FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Tzoumis, KA McMahon, M Munro, JF AF Tzoumis, KA McMahon, M Munro, JF TI Reconciling economic and environmental interests in the US National Brownfields Program: The legacy of superfund and the missing contribution of innovative technology SO JOURNAL OF URBAN TECHNOLOGY LA English DT Article C1 Roosevelt Univ, Sch Policy Studies, Publ Adm Program, Chicago, IL 60605 USA. Oak Ridge Natl Lab, Washington, DC USA. RP Tzoumis, KA (reprint author), Roosevelt Univ, Sch Policy Studies, Publ Adm Program, Chicago, IL 60605 USA. NR 15 TC 3 Z9 3 U1 0 U2 0 PU CARFAX PUBLISHING PI BASINGSTOKE PA RANKINE RD, BASINGSTOKE RG24 8PR, HANTS, ENGLAND SN 1063-0732 J9 J URBAN TECHNOL JI J. Urban Technol. PD DEC PY 1998 VL 5 IS 3 BP 61 EP 77 DI 10.1080/10630739883840 PG 17 WC Urban Studies SC Urban Studies GA 159VM UT WOS:000078195800006 ER PT J AU Anderson, BG Lucas, SG Barrick, RE Heckert, AB Basabilvazo, GT AF Anderson, BG Lucas, SG Barrick, RE Heckert, AB Basabilvazo, GT TI Dinosaur skin impressions and associated skeletal remains from the upper Campanian of southwestern New Mexico: New data on the integument morphology of hadrosaurs SO JOURNAL OF VERTEBRATE PALEONTOLOGY LA English DT Article AB Skin impressions from the tail region of an indeterminate hadrosaur recently excavated from the Upper Cretaceous Ringbone Formation. southwest New Mexico represent the first known dinosaur specimen from New Mexico with impressions of the integument preserved in association with skeletal remains. The mid- to distal-caudal region is represented by 20 articulated centra, other disarticulated centra, a single chevron, ossified tendons and fragmentary bone, including poorly preserved neural spines. The skin impressions are preserved in negative and positive relief between two very fine-grained sandstone beds, interpreted as part of a fluvio-lacustrine facies package. The impression surface is directly below the ossified tendons, and 2.5 m from the articulated vertebral column. The skin impressions are six discrete patches characterized by predominantly apical, circular to ovate tubercles. Measurements of the long and short axes of individual tubercles demonstrate that a distribution of relatively homogenous tubercle sizes occur along the tail section. The tubercles range from 3 to 12 mm and 10 to 16 mm on the short and long axes, respectively. All tubercles examined are ornamented with radiating ridges and grooves that converge at their apex. Presently, the material cannot be identified below the level of Hadrosauridae; however, a comparison of tubercle size, shape and ornamentation described previously from hadrosaur skin impressions indicates the integument morphology of the Ringbone hadrosaur has some similarities to that of the gryposaurs. In general, the complexity of the radial sculpturing, specifically the number of ridges and rugosity, increases with increasing tubercle size. This specific type of ornamentation is not known from modern reptiles or birds; however, the tubercular morphology is similar to that of the lizard Heloderma. Although it is impossible to determine whether the ridges and grooves may have had a physiologic function, these features would increase the surface area of the skin, and therefore may have afforded more efficient heat exchange across the skin, or possibly provided added resistance to tearing and puncturing. C1 Mesa SW Museum, Mesa, AZ 85201 USA. New Mexico Museum Nat Hist, Albuquerque, NM 87104 USA. N Carolina State Univ, Dept Meteorol Earth & Atmospher Sci, Raleigh, NC 27695 USA. Univ New Mexico, Dept Earth & Planetary Sci, Albuquerque, NM 87131 USA. US DOE, Carlsbad, NM 88220 USA. RP Anderson, BG (reprint author), Mesa SW Museum, 53 N MacDonald St, Mesa, AZ 85201 USA. NR 22 TC 16 Z9 20 U1 0 U2 2 PU SOC VERTEBRATE PALEONTOLOGY PI NORTHBROOK PA 60 REVERE DR, STE 500, NORTHBROOK, IL 60062 USA SN 0272-4634 J9 J VERTEBR PALEONTOL JI J. Vertebr. Paleontol. PD DEC PY 1998 VL 18 IS 4 BP 739 EP 745 PG 7 WC Paleontology SC Paleontology GA 154FB UT WOS:000077877100006 ER PT J AU Valentine, GA AF Valentine, GA TI Damage to structures by pyroclastic flows and surges, inferred from nuclear weapons effects SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE pyroclastic density currents; pyroclastic flow; pyroclastic surge; structural damage; volcanic hazards ID COLLAPSING VOLCANIC COLUMNS; NUEE-ARDENTE DEPOSITS; MOUNT ST-HELENS; MT-PELEE; NUMERICAL-MODELS; ERUPTION; MARTINIQUE; TRANSPORT; DYNAMICS; IGNIMBRITES AB In order to define the risk from explosive eruptions, one must constrain both the probability of explosive events and the effects, or consequences, of those events. This paper focuses on the effects of pyroclastic flows and surges there termed 'pyroclastic density currents', or PDCs) on buildings, infrastructure elements, and to some extent on vehicles. PDCs impart a lateral force to such structures in the form of dynamic pressure, which depends on the bulk density of the PDC (which in turn depends mainly on particle concentration) and its velocity. For reasonable ranges of particle concentration (10(-3) to 0.5) and velocities (10 to 300 m/s), dynamic pressure on the upstream face of a structure ranges from similar to 0.1 kPa to 10(4) kPa. Lateral loads ranging up to about 100 kPa were produced during nuclear weapons tests in the 1940s and 1950s that were designed to study the effects of such loading on a variety of structures for civil defense and emergency response purposes in the event of nuclear war. Although considerable simplifications are involved, the data from these weapon tests provide useful analog information for understanding the effects of PDCs. I reviewed data from the nuclear tests, describing the expected damage from different loadings. Tables are provided that define the response of different structural elements (e.g., windows, framing, walls) and whole structures to loading in probabilistic terms, which in principle account for variations in construction quality, orientation, and other factors. Finally, damage documented from historical eruptions at Mt. Lamington (1951), Herculaneum (AD 79 Vesuvius eruption), and St. Pierre (1902 Mt. Pelee eruption) is reviewed. Damage patterns, combined with estimates of velocity, provide an independent estimate of particle concentration in the PDCs. Details of structural damage should be recorded and mapped around future eruptions in order to help refine this aspect of consequence analysis. Another fruitful approach would be to combine numerical simulations of eruption scenarios, which can produce simulated maps of dynamic pressure, with GIS-based data on structures for a given region; the result would be predictions of consequences that could be used for planning and emergency response training. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Geoanal Grp EES5, Los Alamos, NM 87545 USA. RP Valentine, GA (reprint author), Univ Calif Los Alamos Natl Lab, Geoanal Grp EES5, Mail Stop F665, Los Alamos, NM 87545 USA. NR 41 TC 88 Z9 88 U1 4 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD DEC PY 1998 VL 87 IS 1-4 BP 117 EP 140 DI 10.1016/S0377-0273(98)00094-8 PG 24 WC Geosciences, Multidisciplinary SC Geology GA 165YD UT WOS:000078548700008 ER PT J AU Burton, H AF Burton, H TI Robot: Mere machine to transcendent SO LIBRARY JOURNAL LA English DT Book Review C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Burton, H (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 USA SN 0363-0277 J9 LIBR J JI Libr. J. PD DEC PY 1998 VL 123 IS 20 BP 150 EP 151 PG 2 WC Information Science & Library Science SC Information Science & Library Science GA 148BH UT WOS:000077532000277 ER PT J AU Ruzette, AVG Banerjee, P Mayes, AM Pollard, M Russell, TP Jerome, R Slawecki, T Hjelm, R Thiyagarajan, P AF Ruzette, AVG Banerjee, P Mayes, AM Pollard, M Russell, TP Jerome, R Slawecki, T Hjelm, R Thiyagarajan, P TI Phase behavior of diblock copolymers between styrene and n-alkyl methacrylates SO MACROMOLECULES LA English DT Article ID CRITICAL ORDERING TRANSITION; PRESSURE-VOLUME-TEMPERATURE; ANGLE NEUTRON-SCATTERING; POLYMER BLENDS; INTERACTION PARAMETER; POLY(METHYL METHACRYLATE); MICROPHASE SEPARATION; DISORDER TRANSITION; POLYSTYRENE; DEPENDENCE AB In contrast to most diblock copolymers which exhibit the classical upper critical ordering transition (UCOT), polystyrene-b-poly n-butyl methacrylate-PS-b-PBMA-has been shown to undergo ordering upon heating through a lower critical ordering transition(LCOT). Here we report the phase behavior of a family of diblock copolymers formed from styrene and a homologous series of n-alkyl methacrylates, as determined by combined dynamic rheological testing and small-angle neutron scattering (SANS). It is shown that the shortest side chain methacrylates, with the exception of methyl methacrylate, exhibit the LCOT, while for side chains longer than n-butyl, the copolymers exhibit the classical UCOT behavior. Combined group contribution/lattice fluid model calculations of the solubility parameter and specific volume of the corresponding homopolymers qualitatively support these observations. The same calculations were further employed to molecularly design LCOT behavior into a new diblock material consisting of styrene and a random copolymer of methyl and lauryl methacrylate, denoted PS-b-P(MMA-r-LMA). The success of this approach suggests a simple semiquantitative method for predicting and designing the phase behavior of weakly interacting polymer pairs. C1 MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. Univ Massachusetts, Dept Polymer Sci & Engn, Amherst, MA 01003 USA. Univ Liege, Ctr Educ & Res Macromol, B-4000 Cointe Ougree, Belgium. NIST, Cold Neutron Res Facil, Gaithersburg, MD 20899 USA. Los Alamos Natl Lab, Los Alamos Neutron Sci Ctr, Los Alamos, NM 87544 USA. Argonne Natl Lab, Intense Pulsed Neutron Source, Argonne, IL 60439 USA. RP MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA. RI Lujan Center, LANL/G-4896-2012 NR 35 TC 92 Z9 92 U1 2 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD DEC 1 PY 1998 VL 31 IS 24 BP 8509 EP 8516 DI 10.1021/ma981055c PG 8 WC Polymer Science SC Polymer Science GA 150GW UT WOS:000077657000009 ER PT J AU Millero, FJ Dickson, AG Eischeid, G Goyet, C Guenther, P Johnson, KM Key, RM Lee, K Purkerson, D Sabine, CL Schottle, RG Wallace, DWR Lewis, E Winn, CD AF Millero, FJ Dickson, AG Eischeid, G Goyet, C Guenther, P Johnson, KM Key, RM Lee, K Purkerson, D Sabine, CL Schottle, RG Wallace, DWR Lewis, E Winn, CD TI Assessment of the quality of the shipboard measurements of total alkalinity on the WOCE Hydrographic Program Indian Ocean CO2 survey cruises 1994-1996 SO MARINE CHEMISTRY LA English DT Article DE alkalinity; WOCE Hydrographic Program; CO2 ID SEA-WATER; SEAWATER; ACID; THERMODYNAMICS; DISSOCIATION; 273.15-K; 318.15-K; CARBON; MEDIA AB In 1995, we participated in a number of WOCE Hydrographic Program cruises in the Indian Ocean as part of the Joint Global Ocean flux Study (JGOFS) CO, Survey sponsored by the Department of Energy (DOE). Two titration systems were used throughout this study to determine the pH, total alkalinity (TA) and total inorganic carbon dioxide (TCO2) of the samples collected during these cruises. The performance of these systems was monitored by making closed cell titration measurements on Certified Reference Materials (CRMs). A total of 962 titrations were made on six batches of CRMs during the cruises. The reproducibility calculated from these titrations was +/-0.007 in pH, +/-4.2 mu mol kg(-1) in TA, and +/-4.1 mu mol kg(-1) in TCO2. The at-sea measurements on the CRMs were in reasonable agreement with laboratory measurements made on the same batches. These results demonstrate that the CRMs can be used as a reference standard for TA and to monitor the performance of titration systems at sea. Measurements made on the various legs of the cruise agreed to within 6 mu mol kg(-1) at the 15 crossover points. The overall mean and standard deviation of the differences at all the crossovers are 2.1 +/- 2.1 mu mol kg(-1). These crossover results are quite consistent with the overall reproducibility of the CRM analyses for TA (+/-4 mu mol kg(-1)) over the duration of the entire survey, The TA results for the Indian Ocean cruises provide a reliable data set that when combined with TCO2 data can completely characterize the carbonate system. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Calif San Diego, Scripps Inst Oceanog, San Diego, CA 92093 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Princeton Univ, Dept Geosci, Princeton, NJ 08544 USA. NOAA, Atlantic Oceanog & Meteorol Lab, Miami, FL 33149 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. RP Millero, FJ (reprint author), Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. RI Lee, Kitack/G-7184-2015 NR 20 TC 19 Z9 21 U1 5 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD DEC PY 1998 VL 63 IS 1-2 BP 9 EP 20 DI 10.1016/S0304-4203(98)00043-7 PG 12 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 214ZP UT WOS:000081357700002 ER PT J AU Johnson, KM Dickson, AG Eischeid, G Goyet, C Guenther, P Key, RM Millero, FJ Purkerson, D Sabine, CL Schottle, RG Wallace, DWR Wilke, RJ Winn, CD AF Johnson, KM Dickson, AG Eischeid, G Goyet, C Guenther, P Key, RM Millero, FJ Purkerson, D Sabine, CL Schottle, RG Wallace, DWR Wilke, RJ Winn, CD TI Coulometric total carbon dioxide analysis for marine studies: assessment of the quality of total inorganic carbon measurements made during the US Indian Ocean CO2 Survey 1994-1996 SO MARINE CHEMISTRY LA English DT Article DE total carbon dioxide (TCO2); single-operator multiparameter metabolic analyzers (SOMMA) coulometry; marine studies ID PERFORMANCE AB Two single-operator multiparameter metabolic analyzers (SOMMA)-coulometry systems (I and II) for total carbon dioxide (TCO2) were placed on board the R/V Knorr for the US component of the Indian Ocean CO, Survey in conjunction with the World Ocean Circulation Experiment-WOCE Hydrographic Program (WHP), The systems were used by six different measurement groups on 10 WHP Cruises beginning in December 1994 and ending in January 1996. A total of 18,828 individual samples were analyzed for TCO2 during the survey. This paper assesses the analytical quality of these data and the effect of several key factors on instrument performance. Data quality is assessed from the accuracy and precision of certified reference material (CRM) analyses from three different CRM batches. The precision of the method was 1.2 mu mol/kg. The mean and standard deviation of the differences between the known TCO2 for the CRM (certified value) and the CRM TCO2 determined by SOMMA-coulometry were -0.91 +/- 0.58 (n = 470) and - 1.01 +/- 0.44 (n = 513) mu mol/kg for systems I and II, respectively, representing an accuracy of 0.05% for both systems. Measurements of TCO2, made on 12 crossover stations during the survey agreed to within 3 mu mol/kg with an overall mean and standard deviation of the differences of - 0.78 +/- 1.74 mu mol/kg (n = 600). The crossover results are therefore consistent with the precision of the CRM analyses. After 14 months of nearly continuous use, the accurate and the virtually identical performance statistics for the two systems indicate that the cooperative survey effort was extraordinarily successful and will yield a high quality data set capable of fulfilling the objectives of the survey. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Univ Calif San Diego, Scripps Inst Oceanog, San Diego, CA 92093 USA. Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA. Princeton Univ, Dept Geol, Princeton, NJ 08544 USA. Univ Miami, Rosenstiel Sch Marine & Atmospher Sci, Miami, FL 33149 USA. Univ Hawaii, Dept Oceanog, Honolulu, HI 96822 USA. RP Johnson, KM (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. NR 16 TC 33 Z9 35 U1 2 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-4203 J9 MAR CHEM JI Mar. Chem. PD DEC PY 1998 VL 63 IS 1-2 BP 21 EP 37 DI 10.1016/S0304-4203(98)00048-6 PG 17 WC Chemistry, Multidisciplinary; Oceanography SC Chemistry; Oceanography GA 214ZP UT WOS:000081357700003 ER PT J AU Duan, J AF Duan, J TI Passive tracer dispersion with random or periodic source SO MATHEMATICAL AND COMPUTER MODELLING LA English DT Article DE tracer transport; concentration; long-time behavior; periodic concentration; invariant measure ID FLOWS; CHANNELS AB In this paper, the author investigates the impact of external sources on the pattern formation and long-time behavior of concentration profiles of passive tracers in a two-dimensional shear flow. It is shown that a time-periodic concentration profile exists for time-periodic external source, while for random source, the distribution functions of all concentration profiles weakly converge to a unique invariant measure (like a stationary state in deterministic systems) as time goes to infinity. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Duan, J (reprint author), Clemson Univ, Dept Math Sci, Clemson, SC 29634 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-7177 J9 MATH COMPUT MODEL JI Math. Comput. Model. PD DEC PY 1998 VL 28 IS 11 BP 1 EP 5 DI 10.1016/S0895-7177(98)00160-5 PG 5 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 148VX UT WOS:000077555200001 ER PT J AU De Chant, LJ AF De Chant, LJ TI Analytical solutions for diffusive finite reservoir problems using a modified orthogonal expansion method SO MATHEMATICAL AND COMPUTER MODELLING LA English DT Article DE modified orthogonal method; eigenfunction expansion; diffusion; heat equation AB In this paper, we consider an eigenfunction expansion solution method useful for a family of 1-d, unsteady diffusion dominated transport problems (mass, e.g., effluent leakage from a landfill; momentum, e.g., deceleration of shaft in a journal bearing, and energy; e.g., unsteady thermal loading of the skin of a re-entry vehicle) characterized by movement from a bounded, and therefore, time dependent, reservoir to an infinite reservoir. It is demonstrated that simple orthogonality is not applicable to this type of problem. To overcome this limitation, an extended eigenfunction expansion method is developed by modifying the weighting function within the classical orthogonality definition. Using this method, an analytical series solution is obtained. This series solution is also obtained using Laplace transform methods and analytical inversion. Comparison with numerical and approximate methods is good. The analytical solution developed here provides a convenient and physically insightful solution form useful in its own right and as a test problem for numerical implementations. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP De Chant, LJ (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Mail Stop D-413, Los Alamos, NM 87545 USA. NR 15 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0895-7177 J9 MATH COMPUT MODEL JI Math. Comput. Model. PD DEC PY 1998 VL 28 IS 11 BP 73 EP 86 DI 10.1016/S0895-7177(98)00165-4 PG 14 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Mathematics, Applied SC Computer Science; Mathematics GA 148VX UT WOS:000077555200006 ER PT J AU Ren, BR AF Ren, BR TI A bent Laue-Laue monochromator for a synchrotron-based monochromatic x-ray computed tomography system SO MEDICAL PHYSICS LA English DT Article C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Ren, BR (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 2 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0094-2405 J9 MED PHYS JI Med. Phys. PD DEC PY 1998 VL 25 IS 12 BP 2483 EP 2483 DI 10.1118/1.598466 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA 149YX UT WOS:000077635700036 ER PT J AU Holden, TM Tome, CN Holt, RA AF Holden, TM Tome, CN Holt, RA TI Experimental and theoretical studies of the superposition of intergranular and macroscopic strains in Ni-based industrial alloys SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID ZIRCALOY-2; ZIRCONIUM; STRESSES; TEXTURE AB Measurements of the strain response to applied stress in polycrystalline MONEL-400 by neutron diffraction are modeled with the elastoplastic self-consistent (EPSC) theory. The strains in the different crystallographic orientations of grains, which are generated in the tensile test experiments, are shown to be caused by the anisotropy of elastic and plastic deformation with respect to crystallographic orientation. On the basis of the description of the results in the theory, the origin of a number of anomalies of a general nature in measurements by both neutron and X-ray diffraction can be understood. The theory is used to calculate which crystallographic reflections are least sensitive to intergranular effects under uniaxial tension. C1 Natl Res Council Canada, Chalk River Labs, Neutron Program Mat Res, Chalk River, ON K0J 1J0, Canada. Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. AECL Res, Chalk River Labs, Fuel Channels Div, Chalk River, ON K0J 1J0, Canada. RP Holden, TM (reprint author), Natl Res Council Canada, Chalk River Labs, Neutron Program Mat Res, Chalk River, ON K0J 1J0, Canada. RI Tome, Carlos/D-5058-2013 NR 19 TC 19 Z9 19 U1 1 U2 3 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 DEC PY 1998 VL 29 IS 12 BP 2967 EP 2973 DI 10.1007/s11661-998-0204-0 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 152HU UT WOS:000077771700011 ER PT J AU Yang, F Saxena, A Riester, L AF Yang, F Saxena, A Riester, L TI Use of the nanoindentation technique for studying microstructure/crack interactions in the fatigue of 4340 steel SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article AB The objectives of this research are to study the influence of microstructure on the fatigue crack growth behavior in 4340 steel and to explore the application of the nanoindentation technique for determining the plastic deformation zone at a fatigue crack tip. Two heat treatment conditions were chosen for the steel: annealed and quenched plus tempered. The annealed steel consists of coarse pearlite and proeutectoid ferrite, while the quenched and tempered steel consists of fine tempered martensite. Fatigue crack propagation tests were conducted on disklike compact (DCT) specimens. Subsequently, the nanoindentation technique was applied to quantitatively determine the plastic deformation zone at fatigue crack tips. The plastic deformation zone size determined by the nanoindentation test seems larger than the cyclic deformation zone calculated using the fracture mechanics equation, which involves many assumptions. The fatigue crack growth test results show that the annealed steel has a higher resistance to crack growth than the quenched and tempered steel. The fatigue crack in the annealed steel tends to grow along pearlite domain boundaries, or the cementite/ferrite interfaces within a pearlite domain. In contrast, the fatigue crack in the quenched and tempered steel tends to traverse the fine martensite laths. Consequently, the actual crack path in the annealed steel is rougher than in the quenched and tempered steel and more secondary cracks are observed in the annealed steel. C1 Georgia Inst Technol, Sch Mat Sci & Engn, Atlanta, GA 30332 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. NR 9 TC 8 Z9 9 U1 0 U2 9 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 DEC PY 1998 VL 29 IS 12 BP 3029 EP 3036 DI 10.1007/s11661-998-0210-2 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 152HU UT WOS:000077771700017 ER PT J AU Leung, LR Ghan, SJ AF Leung, LR Ghan, SJ TI Parameterizing subgrid orographic precipitation and surface cover in climate models SO MONTHLY WEATHER REVIEW LA English DT Article ID BOUNDARY-LAYER PROPERTIES; ATMOSPHERIC MODELS; SIMULATION; FLUXES; CLOUD; SENSITIVITY; MOUNTAIN; LAKE AB Previous development of the Pacific Northwest National Laboratory's regional climate model has focused on representing orographic precipitation using a subgrid parameterization where subgrid Variations of surface elevation are aggregated to a limited number of elevation classes. An airflow model and a thermodynamic model are used to parameterize the orographic uplift/descent as air parcels dress over mountain barriers or valleys. This paper describes further testing and evaluation of this subgrid parameterization. Building upon this modeling framework, a subgrid vegetation scheme has been developed based on statistical relationships between surface elevation and vegetation. By analyzing high-resolution elevation and vegetation data, a dominant land cover is defined for each elevation band of each model grid cell to account for the subgrid heterogeneity in vegetation. When larger lakes are present, they are distinguished from land within elevation bands and a lake model is used to simulate the thermodynamic properties. The use of the high-resolution vegetation data and the subgrid vegetation scheme has resulted in an improvement in the model's representation of surface cover over the western United States. Simulation using the new vegetation scheme yields a 1 degrees C cooling when compared with a simulation where vegetation was derived from a 30-min global vegetation dataset without subgrid Vegetation treatment; this coding helps to reduce the warm bias previously found in the regional climate model. A 3-yr simulation with the subgrid parameterization in the climate model is compared with observations. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Leung, LR (reprint author), Pacific NW Lab, POB 999,MS K9-30, Richland, WA 99352 USA. RI Ghan, Steven/H-4301-2011 OI Ghan, Steven/0000-0001-8355-8699 NR 43 TC 62 Z9 62 U1 0 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0027-0644 J9 MON WEATHER REV JI Mon. Weather Rev. PD DEC PY 1998 VL 126 IS 12 BP 3271 EP 3291 DI 10.1175/1520-0493(1998)126<3271:PSOPAS>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150GZ UT WOS:000077657300014 ER PT J AU Bruch, R Afanasyeva, N Kano, P Schneider, D AF Bruch, R Afanasyeva, N Kano, P Schneider, D TI Surface spectroscopy of nano- and subnanostructures SO NANOTECHNOLOGY LA English DT Article ID IONS AB In light of recent progress in the fabrication and diagnostics of nanostructures and surfaces, more advanced spectroscopic and imaging methods are necessary in order to elucidate the detailed structure, nature and creation of such microsystems. We present here one especially promising method, namely highly charged ion surface interaction using an electron beam ion trap (EBIT) facility. Specifically we focus on the microspectroscopy, nano- and subnanostructure modification of surfaces and generation of x-rays involving heavy highly charged ion-structure interaction. In this process a large amount of potential energy is deposited by single ions at the surface leading to localized surface defects of subnanosize. In particular, we present new results on highly charged Biq+ (q = 50-71) ions interacting with gold surfaces. A detailed experimental and theoretical analysis is provided for the x-ray spectra from the gold surface. These data have been measured at the Lawrence Livermore National Laboratory EBIT highly charged ion facility. The comparison of our computer simulation with experimental x-ray spectra provides evidence for the formation of subsurface hollow atoms. A striking orbital (n) and angular momentum (l) dependence for hollow atoms formation has been found shedding more light on the dynamics of complex ion-surface and ion-solid interaction processes. Finally, new developments in imaging on nano- and angstrom-scale using heavy highly charged ions are discussed. C1 Univ Nevada, Dept Phys, Reno, NV 89503 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bruch, R (reprint author), Univ Nevada, Dept Phys, Reno, NV 89503 USA. NR 13 TC 3 Z9 3 U1 2 U2 4 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD DEC PY 1998 VL 9 IS 4 BP 346 EP 351 DI 10.1088/0957-4484/9/4/008 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 152AL UT WOS:000077753000008 ER PT J AU Runge, K Sumpter, BG Noid, DW Gray, SK Yang, CY AF Runge, K Sumpter, BG Noid, DW Gray, SK Yang, CY TI Electron propagation along a nanowire: a study in chattering SO NANOTECHNOLOGY LA English DT Article AB Recent fabrication techniques have made it possible to create wires of submicron diameters, as small as a few tens of nanometers, and lengths of hundreds of microns. These nanowires have properties, including electrical conductivities, that differ greatly from the properties of the bulk material. It is necessary to simulate these characteristics of nanowires in an efficient and predictive fashion. While these structures are small on the scale of everyday objects, they still consist of thousands, if not millions, of nuclei and electrons, and hence a full a priori quantum mechanical treatment of these nanowires is not likely to be available in the near future. In this contribution, we present an efficient new approach for the simulation of electron transport along a nanowire. We see that our classical simulations, in which we have propagated one hundred thousand trajectories, result in chaotic scattering, that is chattering, of the electron. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Runge, K (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RI Sumpter, Bobby/C-9459-2013 OI Sumpter, Bobby/0000-0001-6341-0355 NR 6 TC 0 Z9 0 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0957-4484 J9 NANOTECHNOLOGY JI Nanotechnology PD DEC PY 1998 VL 9 IS 4 BP 365 EP 368 DI 10.1088/0957-4484/9/4/012 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied SC Science & Technology - Other Topics; Materials Science; Physics GA 152AL UT WOS:000077753000012 ER PT J AU Beiu, V Makaruk, HE AF Beiu, V Makaruk, HE TI Deeper sparsely nets can be optimal SO NEURAL PROCESSING LETTERS LA English DT Article DE size complexity; threshold gates; limited fan-in; VLSI complexity ID NEURAL NETWORKS; COMPLEXITY; COMPUTATION; TRADEOFFS; THRESHOLD; SIZE AB The starling points of this paper are two size-optimal solutions: (i) one for implementing arbitrary Boolean functions [1]; and (ii) another one for implementing certain sub-classes of Boolean functions [2]. Because VLSI implementations do not cope well with highly interconnected nets - the area of a chip grows with the cube of the fan-in [3] - this paper will analyse the influence of limited fan-in on the size optimality for the two solutions mentioned. First, we will extend a result from Home & Hush [1] valid for fan-in Delta = 2 to arbitrary fan-in. Second, we will prove that size-optimal solutions are obtained for small constant fan-in for both constructions, while relative minimum size solutions can be obtained for fan-ins strictly lower than linear These results are in agreement with similar ones proving that for small constant fan-ins (Delta = 6 ... 9), there exist VLSI-optimal (i.e., minimising AT(2)) solutions [4], while there are similar small constants relating to our capacity of processing information [5]. C1 Univ Calif Los Alamos Natl Lab, Space & Atmospher Div NIS1, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Theoret Div T13 MS B213, Los Alamos, NM 87545 USA. RI Beiu, Valeriu/F-7799-2015 OI Beiu, Valeriu/0000-0001-8185-956X NR 25 TC 15 Z9 15 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 1370-4621 J9 NEURAL PROCESS LETT JI Neural Process. Lett. PD DEC PY 1998 VL 8 IS 3 BP 201 EP 210 DI 10.1023/A:1009665432594 PG 10 WC Computer Science, Artificial Intelligence; Neurosciences SC Computer Science; Neurosciences & Neurology GA 146BY UT WOS:000077408700001 ER PT J AU Hsu, JT Ishii, M Hibiki, T AF Hsu, JT Ishii, M Hibiki, T TI Experimental study on two-phase natural circulation and flow termination in a loop SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article ID 2-PHASE FLOW; CRITERIA AB In order to study the two-phase natural circulation and flow termination during a small break loss of coolant accident in LWR, a hot leg U-bend simulation loop has been built based on the two-phase flow scaling criteria developed under this program. The nitrogen-water system has been used to isolate the key hydrodynamic phenomena from heat transfer problems. Various tests were carried out to establish the basic mechanism of the flow termination and reestablishment as well as to obtain essential information on scale effects of various parameters such as the loop frictional resistance, thermal center, U-bend curvature, and inlet geometry. It was found that the permanent termination of the natural circulation was related to the head balance between the hot and cold legs. The local flow condition at the inverted U-bend could produce intermittent flow, however was not related to the permanent flow termination. The void distribution in a hot leg, flow regime, and natural circulation rate have been measured in detail for various conditions. Significant effects of the inlet geometry on these were observed. Near the flow termination condition, large amplitude flow oscillations occurred. The occurrence of this type of flow instability is important for safety analyses, because it may lead to loop-to-loop oscillations or flow excursions in a prototype system which has a multi-loop configuration. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Reactor Anal & Safety Div, Argonne, IL 60439 USA. Kyoto Univ, Inst Res Reactor, Osaka 5900494, Japan. RP Ishii, M (reprint author), Purdue Univ, Sch Nucl Engn, W Lafayette, IN 47907 USA. RI Hibiki, Takashi /B-6923-2017 OI Hibiki, Takashi /0000-0002-4138-7286 NR 9 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD DEC PY 1998 VL 186 IS 3 BP 395 EP 409 DI 10.1016/S0029-5493(98)00285-4 PG 15 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 153JV UT WOS:000077830700008 ER PT J AU Chung, HM Kassner, TF AF Chung, HM Kassner, TF TI Cladding metallurgy and fracture behavior during reactivity-initiated accidents at high burnup SO NUCLEAR ENGINEERING AND DESIGN LA English DT Article AB High-burnup fuel failure during a reactivity-initiated accident has been a subject of safety-related concern. Because of wide variations in cladding metallurgical and simulation test conditions, it has been difficult to understand the complex failure behavior observed in tests in the SPERT, NSRR and CABRI reactors. In this paper, we propose a failure model that is based on temperature-sensitive tensile properties and fracture toughness. The model assumes that dynamic fracture toughness and high-strain-rate tensile properties of high-burnup cladding are sensitive to temperature and exhibit ductile-brittle transition phenomena similar to those of bcc alloys. Significant effects of temperature and shape of the pulse are predicted when a simulated test is conducted near the cladding material's ductile-brittle transition temperature. Temperature dependence of tensile properties and fracture toughness is, in turn, sensitive to cladding microstructural characteristics such as density, distribution and orientation of hydrides; distribution of oxygen in the metallic phase; and irradiation-induced damage. Because all of these characteristics are strongly influenced by corrosion, the key parameters that influence susceptibility to failure are oxide layer thickness and hydriding behavior. Therefore, high-burnup fuel failure is predicted to be more sensitive to local cladding corrosion (e.g. grid span location) than to fuel burnup. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Chung, HM (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 22 TC 21 Z9 21 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0029-5493 J9 NUCL ENG DES JI Nucl. Eng. Des. PD DEC PY 1998 VL 186 IS 3 BP 411 EP 427 DI 10.1016/S0029-5493(98)00286-6 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA 153JV UT WOS:000077830700009 ER PT J AU Taylor, G Mansfield, DK AF Taylor, G Mansfield, DK TI Intense millimetre wave bursts from plasmas well conditioned with lithium in the tokamak fusion test reactor SO NUCLEAR FUSION LA English DT Article ID EMISSION; TFTR AB Intense bursts of millimetre wave emission are emitted from plasmas in TFTR when the graphite limiter is well conditioned with elemental lithium through the injection of lithium pellets. The bursts have been observed in ohmic and neutral beam heated plasmas fuelled with deuterium only, a mixture of deuterium and tritium or tritium only. The bursting is characterized by 5-10 mu s duration emission spikes of randomly varying amplitude. Spectral analysis of the millimetre wave emission reveals two components; broadband emission, which appears at frequencies below the second harmonic electron cyclotron frequency, and narrowband emission (Delta f < 3 GHz), with an equivalent radiation temperature of over 1 MeV and a frequency corresponding to the upper hybrid frequency near the low field plasma edge. The equivalent radiation temperature of the bursts increases with decreasing edge density, decreasing limiter recycling and increasing plasma stored energy. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08544 USA. RP Taylor, G (reprint author), Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08544 USA. NR 10 TC 2 Z9 2 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD DEC PY 1998 VL 38 IS 12 BP 1819 EP 1827 DI 10.1088/0029-5515/38/12/307 PG 9 WC Physics, Fluids & Plasmas SC Physics GA 157XG UT WOS:000078086500007 ER PT J AU Singh, O Krinsky, S AF Singh, O Krinsky, S TI Orbit compensation for the time-varying elliptically polarized wiggler operating at 100 Hz SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB The time-varying elliptically polarized wiggler, installed in the X13 straight section of the NSLS X-ray ring, generates circularly polarized photons in the energy range of 0.1-10keV, with AC modulation of polarization helicity. The DC vertical magnetic field is produced by a hybrid permanent magnet structure, and the AC horizontal magnetic field is generated by an electromagnet capable of switching at frequencies up to 100 Hz. Here, we discuss the compensation of the residual vertical and horizontal orbit motion utilizing a time-domain algorithm employing a function generator to drive trim coils at the wiggler ends, and the wideband, high precision orbit measurement system of the X-ray ring. The residual orbit motion at 100 Hz has been reduced to a level below 1 mu m, and the device has been run in regular operations with no negative effect on other users. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. RP Singh, O (reprint author), Brookhaven Natl Lab, NSLS, Upton, NY 11973 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1998 VL 418 IS 2-3 BP 249 EP 255 DI 10.1016/S0168-9002(98)00902-4 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100004 ER PT J AU Nomura, M Takahashi, H AF Nomura, M Takahashi, H TI Three-dimensional simulation code for the injector of PNC's high-power, high-duty electron linac SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB We developed a new, three-dimensional simulation code ETRA3D to calculate beam dynamics in the injector of PNC's high-power, high-duty electron linac. In ETRA3D, beam dynamics is calculated by the Hamilton equations, and a space-charge force is determined by the potentials produced by the other electrons. The Hamiltonian is assessed at each time-step, and the length of the time-step is varied by changing in the Hamiltonian to reduce calculation time and errors. The precision of ETRB3D was checked by comparing it with the envelope equation; the agreement between them was good. We demonstrated the capabilities of ETRA3D by an example in which the electron beam is not launched along the axis of a series of the solenoid coils; under this condition, two-dimensional codes cannot calculate its dynamics. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Power Reactor & Nucl Fuel Dev Corp, Oarai Engn Ctr, Adv Technol Div, Oarai, Ibaraki 31113, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Nomura, M (reprint author), Power Reactor & Nucl Fuel Dev Corp, Oarai Engn Ctr, Adv Technol Div, 4002 Narita Cho, Oarai, Ibaraki 31113, Japan. 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1998 VL 418 IS 2-3 BP 256 EP 266 DI 10.1016/S0168-9002(98)00906-1 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100005 ER PT J AU Singh, O Tang, Y Krinsky, S AF Singh, O Tang, Y Krinsky, S TI Orbit feedback at the NSLS SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE feed back systems; NSLS; storage ring AB We discuss the design of global and local orbit feedback systems. Analog and digital implementations at the NSLS are described, as are the results of measurements characterizing performance. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. RP Krinsky, S (reprint author), Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. EM krinsky@bnl.gov NR 18 TC 2 Z9 2 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 DEC 1 PY 1998 VL 418 IS 2-3 BP 267 EP 279 DI 10.1016/S0168-9002(98)00909-7 PG 13 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100006 ER PT J AU Hovater, C Poelker, M AF Hovater, C Poelker, M TI Injection modelocked Ti-sapphire laser with discretely variable pulse repetition rates to 1.56 GHz SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID AMPLIFIER AB A gain-switched diode laser was used to injection modelock a Ti-sapphire laser. The pulse repetition rate of the modelocked Ti-sapphire laser was varied by setting the diode laser pulse repetition rate equal to different multiples of the Ti;sapphire laser cavity fundamental frequency. Pulse repetition rates from 223 MHz (fundamental) to 1.56 GHz (seventh harmonic) were observed. No intracavity modelocking device was required and the Ti-sapphire laser cavity length was not changed. Maximum average output power at 854 nm was 700 mW for all pulse repetition rates when pumped with 6 W from an argon-ion laser. Pulsewidths ranged from 21 to 39 ps (FWHM). Phase noise measurements indicate that timing jitter was 2.5 ps at a pulse repetition rate of 223 MHz. Pulse-to-pulse amplitude fluctuations however, were significant and suggest that active cavity length stabilization may be required for reliable photoinjector applications. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Jefferson Lab, Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. RP Poelker, M (reprint author), Jefferson Lab, Thomas Jefferson Natl Accelerator Facil, Mailstop 16,12000 Jefferson Ave, Newport News, VA 23606 USA. EM poelker@jlab.org NR 11 TC 11 Z9 11 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 DEC 1 PY 1998 VL 418 IS 2-3 BP 280 EP 284 DI 10.1016/S0168-9002(98)00931-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100007 ER PT J AU Cushman, P Heering, A Ronzhin, A AF Cushman, P Heering, A Ronzhin, A TI Studies of hybrid photomultiplier tubes in magnetic fields up to 5 Tesla SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE calorimetry; HPD; magnetic fields; phototube ID DETECTOR AB Single and multi-channel hybrid photodiode tubes were operated inside a very high magnetic field of up to 5 Tesla, The effects of focussing and image displacement on crosstalk and gain were examined as a function of angle in the B-field. Brightening of the response in the illuminated pixel, due to improved focussing of the backscatter was observed. Increased path length through the threshold layer of the photodiode decreased the response at large angles. (C) 1998 Elsevier Science B.V. Ail rights reserved. C1 Univ Minnesota, Dept Phys & Astron, Minneapolis, MN 55455 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Cushman, P (reprint author), Univ Minnesota, Dept Phys & Astron, 116 Church St SE, Minneapolis, MN 55455 USA. EM prisca@mnhep.hep.umn.edu NR 6 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1998 VL 418 IS 2-3 BP 300 EP 305 DI 10.1016/S0168-9002(98)00691-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100009 ER PT J AU Cagliardi, CA Hawker, EA Tribble, RE Koetke, DD Nord, PM McGaughey, PL Brown, CN AF Cagliardi, CA Hawker, EA Tribble, RE Koetke, DD Nord, PM McGaughey, PL Brown, CN TI Hardware trigger system for Fermilab E866 SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE electronic trigger system; programmable CAMAC trigger module; Drell-Yan muon-pair production ID COLLISIONS; COPPER AB E866 is the fourth experiment to be performed with the Fermilab Meson East spectrometer. Originally constructed in 1980 for E605, this spectrometer has since been used for E772 and E789. During these three experiments, the hardware trigger depended on components dating from the early 1970s. The trigger system was rebuilt for E866 to improve its reliability and increase its flexibility. The new system incorporates several new modules designed and built specifically for this experiment. Notably, a custom Track Correlator combines the features of a 16-bit memory lookup and a 12-bit: prescaler into a single extremely fast CAMAC module. The new hardware trigger system and modules are described, and the system performance during E866 is discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. Valparaiso Univ, Dept Phys, Valparaiso, IN 46383 USA. Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. RP Cagliardi, CA (reprint author), Texas A&M Univ, Inst Cyclotron, College Stn, TX 77843 USA. EM cggroup@comp.tamu.edu NR 7 TC 2 Z9 2 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 DEC 1 PY 1998 VL 418 IS 2-3 BP 322 EP 331 DI 10.1016/S0168-9002(98)00903-6 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100012 ER PT J AU Rehm, KE Jiang, CL Paul, M Blumenthal, D Daniel, LA Davids, CN Decrock, P Fischer, SM Henderson, D Lister, C Nickles, J Nolen, J Pardo, RC Schiffer, JP Seweryniak, D Segel, RE AF Rehm, KE Jiang, CL Paul, M Blumenthal, D Daniel, LA Davids, CN Decrock, P Fischer, SM Henderson, D Lister, C Nickles, J Nolen, J Pardo, RC Schiffer, JP Seweryniak, D Segel, RE TI Study of radiative capture reactions with radioactive ion beams SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE radiative capture reactions; radioactive ion beams; FMA ID F-18(P,ALPHA)O-15 REACTION; ASTROPHYSICAL INTEREST; RECOIL SEPARATOR AB A technique for separating and identifying reaction products from radiative capture reactions induced by radioactive ion beams has been developed. The F-18(p,gamma)Ne-19 and O-18(p,gamma)F-19 reactions have been measured in inverse kinematics by identifying the F-19 and Ne-19 reaction products with respect to mass and charge at forward angles in the Fragment Mass Analyzer. A total detection efficiency of 30% and a suppression factor for the incident beam relative to the (p,gamma) reaction products of better than 10(12):1 was achieved. Details of the detection technique, the beam monitoring procedure as well as experience in the use of polypropylene targets in experiments with radioactive beams are discussed. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Hebrew Univ Jerusalem, IL-91904 Jerusalem, Israel. Univ Wisconsin, Madison, WI 53706 USA. Northwestern Univ, Evanston, IL 60208 USA. RP Rehm, KE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 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 DEC 1 PY 1998 VL 418 IS 2-3 BP 355 EP 364 DI 10.1016/S0168-9002(98)00885-7 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100016 ER PT J AU Va'vra, J Maly, JA Va'vra, PM AF Va'vra, J Maly, JA Va'vra, PM TI Soft X-ray production in spark discharges in hydrogen, nitrogen, air, argon and xenon gases SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE X-ray generator; YAP scintillation detector; sparking ID DEEP DIRAC LEVELS; ELECTRON TRANSITIONS AB We describe a generator of soft X-rays of energy between 2 and 10 keV by sparking in hydrogen, air, nitrogen, argon and xenon gases at low pressure with a sparking voltage as low as similar to 0.8 kV. The X-ray events appear to come in clusters, with an average mean multiplicity of 3 per single event into the solid angle of our detector; the extrapolated production into a 4 pi-solid angle is more than similar to 1500 pulses per event, assuming the isotropic distribution. The device operates with the peak spark currents 0.2-0.5 kA and the total spark charge more than 4 x 10(14) electrons/spark. The spark stored energy 0.024-0.17 J/pulse is more than four orders of magnitude smaller compared to experiments reporting similar X-ray production. The X-ray generator can be used as a simple monitor of the gaseous detectors, or a device to study various gaseous phenomena occurring in large sparks. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Appl Sci Consultants, San Jose, CA 95123 USA. RP Va'vra, J (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, SLAC Bin 62,POB 4349, Stanford, CA 94309 USA. NR 19 TC 3 Z9 3 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD DEC 1 PY 1998 VL 418 IS 2-3 BP 405 EP 419 DI 10.1016/S0168-9002(98)00926-7 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UQ UT WOS:000077219100021 ER PT J AU Bechthold, U Ullrich, J Ramm, U Kraft, G Hagmann, S Reinhold, CO Schultz, DR Schmidt-Bocking, H AF Bechthold, U Ullrich, J Ramm, U Kraft, G Hagmann, S Reinhold, CO Schultz, DR Schmidt-Bocking, H TI Intra-atomic double scattering of Binary Encounter electrons in heavy ion collisions with gas targets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 4th International Symposium on Swift Heavy Ions in Matter (SHIM98) CY MAY 11-15, 1998 CL BERLIN, GERMANY SP Commissariat Energie Atom (CEA/DSM/DRECAM), Deutsch Forsch Gemeinschaft (DFG), Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung, Hahn-Meitner-Inst GmbH, Rontec GmbH, Varian GmbH ID IONIZATION SPECTRUM; TRACK STRUCTURE; EMISSION AB Experimental evidence for intra-atomic double scattering of fast Binary Encounter (BE) electrons produced in collisions of 5.9 MeV/u U29+ with various gas targets is presented. A broad distribution of electrons displaying the shape of the (BE) peak at twice of the velocity of the ion beam at angles up to 135 degrees is observed in the double differential electron emission spectra, This emission is attributed to target electrons ejected in a knock-on collision that are subsequently elastically scattered at their own target nuclear potential. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Kansas State Univ, Manhattan, KS 66506 USA. Kansas State Univ, Manhattan, KS 66506 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Univ Frankfurt, Inst Kernphys, D-60486 Frankfurt, Germany. RP Bechthold, U (reprint author), Gesell Schwerionenforsch GmbH, Planckstr 1, D-64291 Darmstadt, Germany. OI Reinhold, Carlos/0000-0003-0100-4962 NR 17 TC 2 Z9 2 U1 0 U2 0 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 DEC PY 1998 VL 146 IS 1-4 BP 46 EP 51 DI 10.1016/S0168-583X(98)00440-6 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 151KN UT WOS:000077719400007 ER PT J AU Schaffer, HW Mokler, PH Dunford, RW Kozhuharov, C Kramer, A Ludziejewski, T Prinz, HT Rymuza, P Sarkadi, L Stohlker, T Swiat, P Warczak, A AF Schaffer, HW Mokler, PH Dunford, RW Kozhuharov, C Kramer, A Ludziejewski, T Prinz, HT Rymuza, P Sarkadi, L Stohlker, T Swiat, P Warczak, A TI Measurement of the spectral shape for the two-photon decay in heliumlike gold SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 4th International Symposium on Swift Heavy Ions in Matter (SHIM98) CY MAY 11-15, 1998 CL BERLIN, GERMANY SP Commissariat Energie Atom (CEA/DSM/DRECAM), Deutsch Forsch Gemeinschaft (DFG), Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung, Hahn-Meitner-Inst GmbH, Rontec GmbH, Varian GmbH ID 2-PHOTON DECAY; STATE; EXCITATION; S-1(0) AB Progress on a measurement of the spectral distribution of the two-photon decay of the 1s2s S-1(0) level in the strong central fields of heavy heliumlike ions is reported. A measurement of the exact shape of the continuous spectrum of the two-photon decay in heavy heliumlike ions provides a sensitive test of the details of the complete structure of a heliumlike system. In our experiment at GSI, a beam of 106.6 MeV/u Au77+ ions was excited by a thin Aluminum foil and the subsequent decays were observed in an array of Ge(i) detectors. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Argonne Natl Lab, Argonne, IL 60439 USA. Soltan Inst Nucl Studies, PL-05400 Swierk, Poland. Inst Nucl Res, H-4001 Debrecen, Hungary. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. RP Schaffer, HW (reprint author), Gesell Schwerionenforsch GmbH, Planckstr 1, D-64291 Darmstadt, Germany. NR 12 TC 1 Z9 1 U1 0 U2 1 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 DEC PY 1998 VL 146 IS 1-4 BP 62 EP 66 DI 10.1016/S0168-583X(98)00449-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 151KN UT WOS:000077719400010 ER PT J AU Reinhold, CO Kurpick, P Burgdorfer, J Yoshida, S Gervais, B AF Reinhold, CO Kurpick, P Burgdorfer, J Yoshida, S Gervais, B TI Electronic excitation in transmission of relativistic H- ions through thin foils SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS LA English DT Article; Proceedings Paper CT 4th International Symposium on Swift Heavy Ions in Matter (SHIM98) CY MAY 11-15, 1998 CL BERLIN, GERMANY SP Commissariat Energie Atom (CEA/DSM/DRECAM), Deutsch Forsch Gemeinschaft (DFG), Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung, Hahn-Meitner-Inst GmbH, Rontec GmbH, Varian GmbH ID IONIZATION; COLLISIONS; HYDROGEN; STATE; ATOMS AB We describe a theoretical model to study the transmission or relativistic H- ions through thin carbon foils. Our approach is based on a Monte Carlo solution of the Langevin equation describing electronic excitations of the atoms during the transport through the foil. Calculations for the subshell populations of outgoing hydrogen atoms are found to be in good agreement with recent experimental data on an absolute scale and show that there exists a propensity for populating extreme Stark states. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Phys, MS 6373, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Ctr Interdisciplinaire Rech Ions Lourds, CEA CNRS, Lab Mixte, F-14040 Caen, France. RP Reinhold, CO (reprint author), Oak Ridge Natl Lab, Div Phys, MS 6373, Bldg 6003, Oak Ridge, TN 37831 USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 22 TC 2 Z9 2 U1 0 U2 0 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 DEC PY 1998 VL 146 IS 1-4 BP 76 EP 81 DI 10.1016/S0168-583X(98)00483-2 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 151KN UT WOS:000077719400013 ER PT J AU Lvovsky, L Ioshikhes, I Raja, MC Zevin-Sonkin, D Sobolev, IA Liberzon, A Shwartzburd, J Ulanovsky, LE AF Lvovsky, L Ioshikhes, I Raja, MC Zevin-Sonkin, D Sobolev, IA Liberzon, A Shwartzburd, J Ulanovsky, LE TI Interdependence between DNA template secondary structure and priming efficiencies of short primers SO NUCLEIC ACIDS RESEARCH LA English DT Article ID DUPLEX STABILITY; RNA; THERMODYNAMICS; PREDICTIONS; MISMATCHES; PARAMETERS; STACKING AB Here we analyze the effect of DNA folding on the performance of short primers and describe a simple technique for assessing hitherto uncertain values of thermodynamic parameters that determine the folding of single-stranded DNA into secondary structure. An 8mer with two degenerate positions is extended simultaneously at several complementary sites on a known template (M13mp18) using one, two or three (but never all four) of the possible dNTPs, The length of the extension is site specific because it is limited by the first occurrence in the downstream template sequence of a base whose complementary dNTP is not present. The relative priming efficiencies of different sites are then ranked by comparing their band brightnesses on a gel. The priming efficiency of a short primer (unlike conventional long primers) depends dramatically on the secondary structure of the template at and around the priming site. We calculated the secondary structure and its effect on priming using a simple model with relatively few parameters which were then optimized to achieve the best match between the predictions and the actual rankings of the sites in terms of priming efficiency, This work introduces an efficient and conceptually novel approach that in the future can make use of more data to optimize a larger set of DNA folding parameters in a more refined model, The model we used, however crude it may be, significantly improved the prediction of priming efficiencies of 8mer primers and appreciably raised the success rate of our DNA sequencing technique (from 67 to 91% with a significance of P < 7 x 10(-5)), which uses such primers. C1 Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. RP Ulanovsky, LE (reprint author), Argonne Natl Lab, Ctr Mech Biol & Biotechnol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM levy@anl.gov NR 16 TC 3 Z9 3 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD DEC 1 PY 1998 VL 26 IS 23 BP 5525 EP 5532 DI 10.1093/nar/26.23.5525 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 147WE UT WOS:000077487400038 PM 9826780 ER PT J AU Monegato, G Lyness, JN AF Monegato, G Lyness, JN TI The Euler-Maclaurin expansion and finite-part integrals SO NUMERISCHE MATHEMATIK LA English DT Article AB In this paper we compare G(p), the Mellin transform (together with its analytic continuation), and (G) over bar(p), the related Hadamard finite-part integral of a function g(x), which decays exponentially at infinity and has specified singular behavior at the origin. Except when p is a nonpositive integer, these coincide. When p is a nonpositive integer, (G) over bar(p) is well defined, but G(p) has a pole. We show that the terms in the Laurent expansion about this pole can be simply expressed in terms of the Hadamard finite-part integral of a related function. This circumstance is exploited to provide a conceptually uniform proof of the various generalizations of the Euler-Maclaurin expansion for the quadrature error functional. C1 Politecn Torino, Dipartimento Matemat, I-10129 Turin, Italy. Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Monegato, G (reprint author), Politecn Torino, Dipartimento Matemat, Cso Abruzzi 24, I-10129 Turin, Italy. NR 11 TC 16 Z9 17 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0029-599X J9 NUMER MATH JI Numer. Math. PD DEC PY 1998 VL 81 IS 2 BP 273 EP 291 DI 10.1007/s002110050392 PG 19 WC Mathematics, Applied SC Mathematics GA 153QG UT WOS:000077843300005 ER PT J AU Weiss, JD Stallard, BR Garcia, MJ AF Weiss, JD Stallard, BR Garcia, MJ TI Using optical absorption to measure the state of charge of lead-acid batteries SO OPTICAL ENGINEERING LA English DT Article DE fiber optic sensors; optical absorption; battery monitoring AB Proposed here is a method of measuring the state of charge of lead-acid batteries based on the assumption that the addition of sulfuric acid to water will reduce the optical absorption at certain absorption peaks of pure water. This reduction is expected to result from the accompanying drop in the concentration of water molecules. Measurements of the absorption in the vicinity of 0.97, 1.20, and 1.45 mu m indicate that this is indeed the case, although deviations from a linear dependence on water concentration are noted. Two ways of implementing this phenomenon in a lead-acid battery are presented; one involves an absorption cell in a flooded battery, while the second involves an optical fiber woven into an absorbed-glass-mat battery. In the second case, the absorptive electrolyte serves as the cladding of the optical fiber and introduces attenuated total internal reflection into what would otherwise be perfectly guided modes. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)02312-5]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Weiss, JD (reprint author), Sandia Natl Labs, Mail Stop 1081,POB 5800, Albuquerque, NM 87185 USA. NR 8 TC 1 Z9 1 U1 2 U2 2 PU SPIE - INTERNATIONAL SOCIETY FOR OPTICAL ENGINEERING PI BELLINGHAM PA POB 10, BELLINGHAM, WA 98227-0010 USA SN 0091-3286 J9 OPT ENG JI Opt. Eng. PD DEC PY 1998 VL 37 IS 12 BP 3254 EP 3259 DI 10.1117/1.601999 PG 6 WC Optics SC Optics GA 147VN UT WOS:000077518300022 ER PT J AU Wang, HY LeSar, R Rickman, JM AF Wang, HY LeSar, R Rickman, JM TI Analysis of dislocation microstructures: impact of force truncation and slip systems SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID DISTRIBUTIONS; SIMULATION; DYNAMICS AB We present a systematic investigation of the microstructures resulting from simulations of overdamped dislocation dynamics and quantitatively assess the impact of Various slip system constraints and force truncation schemes. We show that the degree of local ordering in these structures correlates with the number of active slip planes. We compare the microstructures resulting from a common force cut-off scheme with those generated by applying full periodic boundary conditions and find that the dislocation structure is quite sensitive to the choice of boundary conditions. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Lehigh Univ, Dept Mat Sci & Engn, Bethlehem, PA 18015 USA. RP LeSar, R (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RI LeSar, Richard/G-1609-2012 NR 19 TC 12 Z9 12 U1 1 U2 1 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 DEC PY 1998 VL 78 IS 6 BP 1195 EP 1213 PG 19 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 146KH UT WOS:000077427500001 ER PT J AU Zhang, XF AF Zhang, XF TI A defective structure for Tl-deficient Tl2-xBa2CaCu2Oy superconductors SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID CA-CU-O; ELECTRON-DIFFRACTION; CRYSTAL-STRUCTURE; TL2BA2CACU2O8 FILMS; NEUTRON-DIFFRACTION; PHASE-FORMATION; THIN-FILMS; STABILITY; SYSTEM; MICROSCOPY AB Considerable Tl deficiency has been detected in the Tl2Ba2CaCu2Oy (Tl-2212) superconducting phase formed in thin films and polycrystals. Transmission electron microscopy was used to characterize the structure of this Tl-deficient phase. It has been found that the space group changes to be I4mm which is apparently different from I4/mmm as usually reported for the Tl-2212 phase. The change in the space group is due to a lack of the (001) mirrors in the defective Tl-2212 structure which can be directly imaged by high-resolution electron microscopy. Image simulations confirmed a proposed structure model in which inhomogeneously distributed Tl vacancies and Tl disorder in the Tl-O layers are considered to be responsible for the symmetry change. The stability of such a defective Tl-2212 phase will be discussed. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. Chinese Acad Sci, Beijing Lab Electron Microscopy, Beijing 100080, Peoples R China. RP Zhang, XF (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop K765, Los Alamos, NM 87545 USA. NR 30 TC 1 Z9 1 U1 0 U2 0 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 DEC PY 1998 VL 78 IS 6 BP 1339 EP 1351 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA 146KH UT WOS:000077427500008 ER PT J AU Saxena, A Dandoloff, R Lookman, T AF Saxena, A Dandoloff, R Lookman, T TI Deformable curved magnetic surfaces SO PHYSICA A LA English DT Article; Proceedings Paper CT Collective Phenomena in Physics Meeting on Dynamkcs and Kinetics of Fluids and Materials (CPiP 98) CY JAN 07-10, 1998 CL UNIV WEST INDIES, CAVE HILL, BRIDGETOWN, BARBADOS HO UNIV WEST INDIES, CAVE HILL DE magnetoelasticity; self-duality; sine-Gordon and double sine-Gordon solutions ID COMPRESSIBLE HEISENBERG CHAIN; GEOMETRICAL FRUSTRATION; STATISTICAL-MECHANICS; SOLITONS; VESICLES; CURVATURE; MEMBRANES; INSTABILITY; EXCITATIONS; TRANSITIONS AB We study curved magnetic surfaces in the context of soft condensed matter. Specifically, we consider classical Heisenberg spins on elastically deformable curved geometries in orthogonal curvilinear coordinates such as a cylinder, a torus, etc. We find that a mismatch of length scales (geometrical frustration) in the presence of magnetic solitons leads to an elastic soliton (deformation) on the magnetic surfaces. We illustrate the results on (i) a circular cylinder with either spin anisotropy or external magnetic field or multiple solitons, (ii) an elliptic cylinder and (iii) a torus section. Our results are applicable to microtubules and vesicles (spheroidal or toroidal) comprised of magnetic organic materials such as magnetic polymers. (C) 1998 Elsevier Science B.V. All rights reserved. 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. Univ Western Ontario, Dept Appl Math, London, ON N6A 5B7, Canada. RP Saxena, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM abs@aegir.lanl.gov NR 50 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 1 PY 1998 VL 261 IS 1-2 BP 13 EP 25 DI 10.1016/S0378-4371(98)00378-1 PG 13 WC Physics, Multidisciplinary SC Physics GA 149HA UT WOS:000077598000003 ER PT J AU Gronbech-Jensen, N Beardmore, KM Pincus, P AF Gronbech-Jensen, N Beardmore, KM Pincus, P TI Interactions between charged spheres in divalent counterion solution SO PHYSICA A LA English DT Article; Proceedings Paper CT Collective Phenomena in Physics Meeting on Dynamkcs and Kinetics of Fluids and Materials (CPiP 98) CY JAN 07-10, 1998 CL UNIV WEST INDIES, CAVE HILL, BRIDGETOWN, BARBADOS HO UNIV WEST INDIES, CAVE HILL DE electrostatics; colloids; complex fluids ID COLLOIDAL SUSPENSIONS; POLYELECTROLYTES; ATTRACTION; MACROIONS AB We simulate model systems of charged spherical particles in their counterion solution and measure the thermodynamic pressure and the pair distribution function from which we derive effective potentials of mean force. For a system with only electrostatic and hard core interactions, we investigate the effective potential between two like-charged spheres in divalent counterion solution as a function of concentration. We find a strong attractive interaction for high concentration and a global repulsive effective interaction for dilute systems. The results indicate a first order phase transition in sphere-counterion density as a function of global concentration and the effective sphere-sphere potentials in the dilute (solvated) regime suggest significant density fluctuations due to short range local minima in the effective energy surface. Our results arise from a minimal approach model of several recent experiments on polystyrene latex particles in monovalent counterion solution. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. RP Gronbech-Jensen, N (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM ngj@mimer.lanl.gov NR 20 TC 76 Z9 76 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 1 PY 1998 VL 261 IS 1-2 BP 74 EP 81 DI 10.1016/S0378-4371(98)00369-0 PG 8 WC Physics, Multidisciplinary SC Physics GA 149HA UT WOS:000077598000008 ER PT J AU Pellegrini, M Larsen, NA Yeates, TO Gronbech-Jensen, N AF Pellegrini, M Larsen, NA Yeates, TO Gronbech-Jensen, N TI A new constrained Langevin method: application to protein crystallographic refinement SO PHYSICA A LA English DT Article; Proceedings Paper CT Collective Phenomena in Physics Meeting on Dynamkcs and Kinetics of Fluids and Materials (CPiP 98) CY JAN 07-10, 1998 CL UNIV WEST INDIES, CAVE HILL, BRIDGETOWN, BARBADOS HO UNIV WEST INDIES, CAVE HILL DE constrained dynamics; protein conformational variability; X-ray refinement ID RESTRAINED MOLECULAR-DYNAMICS; CRYSTAL-STRUCTURES; THERMAL MOTION; DISORDER AB We present an algorithm to perform Langevin simulations with constraints. The algorithm iteratively solves a set of linear equations to find the Lagrange multipliers that satisfy the constraints. We apply the algorithm to a polypeptide, and demonstrate that it is stable within a range of timesteps. The algorithm is then used to perform X-ray crystallographic refinement of proteins. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Angeles, Inst Mol Biol, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Pellegrini, M (reprint author), Univ Calif Los Angeles, Inst Mol Biol, Los Angeles, CA 90095 USA. OI Yeates, Todd/0000-0001-5709-9839 NR 11 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD DEC 1 PY 1998 VL 261 IS 1-2 BP 224 EP 231 DI 10.1016/S0378-4371(98)00375-6 PG 8 WC Physics, Multidisciplinary SC Physics GA 149HA UT WOS:000077598000020 ER PT J AU Achucarro, A Borrill, J Liddle, AR AF Achucarro, A Borrill, J Liddle, AR TI On the formation of non-topological string networks SO PHYSICA B LA English DT Article; Proceedings Paper CT Symposium on Quantum Phenomena at Low Temperatures - Disorder, Defects, and Decoherence in Quantum Systems CY JAN 07-11, 1998 CL LAMMI, FINLAND DE string simulation; defect formation; semilocal string; gauge fields ID ELECTROWEAK STRINGS; COSMIC STRINGS; UNCONVENTIONAL SUPERCONDUCTORS; SEMILOCAL STRINGS; BUBBLE COLLISIONS; PHASE-TRANSITIONS; SUPERFLUID HE-3; EARLY UNIVERSE; DEFECTS; SIMULATION AB We review recent simulations of the formation of a particular class of non-topological defects known as semilocal strings during a phase transition. Semilocal strings have properties that are intermediate between topological cosmic strings and stable electroweak strings, and therefore the observation that they could form in substantial quantities during a cosmological phase transition has implications for structure formation, baryogenesis, etc. At the same time, and from a purely theoretical point of view, they provide a very good testing ground for investigating the role of gauge fields in defect formation. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 UPV, EHU, Dept Theoret Phys, Bilbao 48080, Spain. Univ Groningen, Inst Theoret Phys, Groningen, Netherlands. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Natl Energy Res Sci Comp Ctr, Berkeley, CA USA. Univ Calif Berkeley, Natl Lab, Berkeley, CA 94720 USA. Univ Sussex, Ctr Astron, Brighton BN1 9QJ, E Sussex, England. RP Achucarro, A (reprint author), UPV, EHU, Dept Theoret Phys, Bilbao 48080, Spain. RI Liddle, James/A-4867-2013 OI Liddle, James/0000-0002-2508-7910 NR 43 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC PY 1998 VL 255 BP 116 EP 125 DI 10.1016/S0921-4526(98)00458-X PG 10 WC Physics, Condensed Matter SC Physics GA 143ZH UT WOS:000077287100011 ER PT J AU Zhang, B Brooks, JS Wang, Z Perenboom, JAAJ Simmons, J Reno, J Lumpkin, N O'Brien, JL Clark, R AF Zhang, B Brooks, JS Wang, Z Perenboom, JAAJ Simmons, J Reno, J Lumpkin, N O'Brien, JL Clark, R TI Quantization and chiral edge state properties in nearly 3D quantum well structures SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 13th International Conference on High Magnetic Fields in Semiconductor Physics CY AUG 10-14, 1998 CL UNIV NIJMEGEN, NIJMEGEN, NETHERLANDS HO UNIV NIJMEGEN DE edge states; quantum Hall effect; quantum well; two-dimensional gas; GaAs ID HALL; TRANSITION AB We report magneto-transport measurements including Hall, R(xy), longitudinal, R(xx), and vertical, R(zz), magnetoresistance on nearly 3-dimensional (3D) 200 layer GaAs/AlGaAs quantum well structures. Although the interlayer bandwidth is nearly 20% of the Fermi energy, we still observe complete quantization of the Hall resistance for the 3D quantum Hall state. The temperature dependence of the R(xx) minimum shows two unusual features: initially, at higher temperatures 1 K where the quantum Hall state develops, a gap with an activation energy much smaller than the Landau gap is observed; in the low temperature limit 0.030 K a variable range hopping behavior takes over with a residual resistivity limit. Independent measurements of G(zz) (in 3D approximate to 1/R(zz)) where the chiral edge states dominate the vertical transport show the same temperature dependence. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. Univ Nijmegen, High Field Magnet Lab, NL-6525 ED Nijmegen, Netherlands. Univ Nijmegen, Mat Res Inst, NL-6525 ED Nijmegen, Netherlands. Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ New S Wales, Natl Pulsed Magnet Lab, Sydney, NSW 2052, Australia. Univ New S Wales, Semicond Nanofabricat Facil Sch Phys, Sydney, NSW 2052, Australia. RP Zhang, B (reprint author), Boston Coll, Dept Phys, Chestnut Hill, MA 02167 USA. RI O'Brien, Jeremy/A-6290-2008; OI O'Brien, Jeremy/0000-0002-3576-8285 NR 13 TC 3 Z9 3 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC PY 1998 VL 256 BP 279 EP 282 DI 10.1016/S0921-4526(98)00597-3 PG 4 WC Physics, Condensed Matter SC Physics GA 152KE UT WOS:000077775900057 ER PT J AU Marinescu, DC Quinn, JJ Wojs, A AF Marinescu, DC Quinn, JJ Wojs, A TI Collective excitations in a 2D electron system: Canted field geometry SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 13th International Conference on High Magnetic Fields in Semiconductor Physics CY AUG 10-14, 1998 CL UNIV NIJMEGEN, NIJMEGEN, NETHERLANDS HO UNIV NIJMEGEN DE collective excitations; spin polarization AB We investigate the charge and spin collective modes induced in a 2D electron gas by a weak electromagnetic perturbation in the presence of a dc magnetic field which makes an angle theta with the electron layer. The excitation frequencies are determined within the framework of the Landau-Silin theory of Fermi liquids by solving a semi-classical equation for transport in the self-consistent electromagnetic field associated with particle density fluctuations. The quasiparticle interaction is spin dependent and varies parametrically with the degree of spin polarization. In the long wavelength limit, we obtain analytic results for the frequencies of the collective modes as functions of theta. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. RP Marinescu, DC (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM marinescudc@ornl.gov RI Wojs, Arkadiusz/M-9381-2015 OI Wojs, Arkadiusz/0000-0002-3624-5275 NR 5 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC PY 1998 VL 256 BP 474 EP 476 DI 10.1016/S0921-4526(98)00526-2 PG 3 WC Physics, Condensed Matter SC Physics GA 152KE UT WOS:000077775900097 ER PT J AU Heron, RJ Lewis, RA Clark, RG Starrett, RP Kane, BE Facer, GR Lumpkin, NE Rickel, DG Pfeiffer, LN West, KW AF Heron, RJ Lewis, RA Clark, RG Starrett, RP Kane, BE Facer, GR Lumpkin, NE Rickel, DG Pfeiffer, LN West, KW TI Far-infrared studies of extremely high mobility gated GaAs/AlGaAs structures in magnetic fields SO PHYSICA B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT 13th International Conference on High Magnetic Fields in Semiconductor Physics CY AUG 10-14, 1998 CL UNIV NIJMEGEN, NIJMEGEN, NETHERLANDS HO UNIV NIJMEGEN DE far-infrared; magnetospectroscopy; heterostructures ID CYCLOTRON-RESONANCE LINEWIDTH; HETEROSTRUCTURES AB Extremely narrow cyclotron resonance linewidths are reported in GaAs-based heterostructures measured using double-modulated far-infrared photoconductivity. At low carrier densities and temperatures full widths at half maximum as small as 6 mT are observed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia. Univ Wollongong, Dept Engn Phys, Wollongong, NSW 2522, Australia. Univ Calif Los Alamos Natl Lab, NHMFL, Los Alamos, NM 87545 USA. Lucent Technol, Bell Labs, Murray Hill, NJ 07974 USA. RP Heron, RJ (reprint author), Univ New S Wales, Sch Phys, Sydney, NSW 2052, Australia. EM rjh@newt.phys.unsw.edu RI Lewis, Roger/D-3135-2014 OI Lewis, Roger/0000-0002-4598-7553 NR 10 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD DEC PY 1998 VL 256 BP 481 EP 485 DI 10.1016/S0921-4526(98)00491-8 PG 5 WC Physics, Condensed Matter SC Physics GA 152KE UT WOS:000077775900099 ER PT J AU Daney, DE Maley, MP Boenig, HJ Willis, JO Coulter, JY Gherardi, L Coletta, G AF Daney, DE Maley, MP Boenig, HJ Willis, JO Coulter, JY Gherardi, L Coletta, G TI Single-phase AC losses in prototype HTS conductors for superconducting power transmission lines SO PHYSICA C LA English DT Article; Proceedings Paper CT International Cryogenic Materials Conference on AC Loss and Stability of Low-and High-T(c) Superconductors (ICMC98) CY MAY 10-13, 1998 CL UNIV TWENTE, ENSCHEDE, NETHERLANDS SP ICMC, FOM, STW, Main Board Univ Twente (Coll van Bestuur), Univ Fdn (Stichting Universiteitsfonds Twente) HO UNIV TWENTE DE transport AC loss; Bi-2223 tape; calorimetric method; power transmission cable AB We report single-phase AC loss measurements on 8-, 4-, and 3-layer, multi-strand, HTS prototype conductors for power transmission lines. We use both calorimetric and electrical techniques. The agreement between the two techniques suggests that the interlayer current distribution in l-m long conductors are representative of those in long conductors. The losses for the 8- and 4-layer conductors are in rough agreement, with the 8-layer losses being somewhat lower. The 3-layer conductor losses are substantially higher - probably due to unbalanced azimuthal currents for this configuration. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Pirelli Cavi & Sistemi, I-20126 Milan, Italy. RP Daney, DE (reprint author), Univ Calif Los Alamos Natl Lab, MS J580,POB 1663, Los Alamos, NM 87545 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1998 VL 310 IS 1-4 BP 236 EP 239 DI 10.1016/S0921-4534(98)00468-7 PG 4 WC Physics, Applied SC Physics GA 152YT UT WOS:000077806200046 ER PT J AU Sumption, MD Scanlan, RM Collings, EW AF Sumption, MD Scanlan, RM Collings, EW TI Coupling current control in Rutherford cables wound with NbTi, Nb3Sn, and Bi : 2212/Ag SO PHYSICA C LA English DT Article; Proceedings Paper CT International Cryogenic Materials Conference on AC Loss and Stability of Low-and High-T(c) Superconductors (ICMC98) CY MAY 10-13, 1998 CL UNIV TWENTE, ENSCHEDE, NETHERLANDS SP ICMC, FOM, STW, Main Board Univ Twente (Coll van Bestuur), Univ Fdn (Stichting Universiteitsfonds Twente) HO UNIV TWENTE DE Rutherford cable; NbTi; Nb3Sn; Bi : 2212 tape; coupling loss; interstrand resistance ID RESISTANCE AB Calorimetric measurements of AC loss have been performed on Rutherford cables wound with NbTi, Nb3Sn, and Bi:2212/Ag strands, respectively. For the NbTi cables Ni and stabrite coatings had been applied, while for the Nb3Sn and Bi:2212/Ag cables the strand surfaces were just bare Cu or Ag, respectively. Most of the cables contained resistive cores: ribbons of kapton, or titanium (NbTi), stainless steel (NbTi and Nb3Sn), and nichrome-80 (Bi:2212/Ag). In all cases the cores were found to lead to a strong suppression of the face-on (field normal to the broad cable face) coupling current loss; to such an extent that even the Bi:2212/Ag cables, which would otherwise be severely cross-sintered, show the possibility of acceptable coupling loss. Effective crossover interstrand contact resistances are calculated and normalized to a standard cable specification ('LHC inner') for the purpose of intercomparison. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. Lawrence Berkeley Lab, Superconducting Magnet Grp, Berkeley, CA 94720 USA. RP Sumption, MD (reprint author), Ohio State Univ, Dept Mat Sci & Engn, Columbus, OH 43210 USA. RI Sumption, Mike/N-5913-2016 OI Sumption, Mike/0000-0002-4243-8380 NR 10 TC 5 Z9 5 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC PY 1998 VL 310 IS 1-4 BP 291 EP 295 DI 10.1016/S0921-4534(98)00478-X PG 5 WC Physics, Applied SC Physics GA 152YT UT WOS:000077806200056 ER PT J AU Ghosh, AK Sampson, WB Kim, SW Leroy, D Oberli, LR Wilson, MN AF Ghosh, AK Sampson, WB Kim, SW Leroy, D Oberli, LR Wilson, MN TI Stability measurements on cored cables in normal and superfluid helium SO PHYSICA C LA English DT Article; Proceedings Paper CT International Cryogenic Materials Conference on AC Loss and Stability of Low-and High-T(c) Superconductors (ICMC98) CY MAY 10-13, 1998 CL UNIV TWENTE, ENSCHEDE, NETHERLANDS SP ICMC, FOM, STW, Main Board Univ Twente (Coll van Bestuur), Univ Fdn (Stichting Universiteitsfonds Twente) HO UNIV TWENTE DE stability; NbTi; Rutherford cable; 'porous-metal' filling; superfluid helium ID MINIMUM QUENCH ENERGIES; RUTHERFORD CABLES; WIRES AB The relative stability of LHC type cables has been measured by the direct heating of one of the individual strands with a short duration current pulse. The minimum energy required to initiate a quench has been determined for a number of cables which have a central core to increase the effective inter-strand cross-over resistance. Experiments were performed in both normal helium at 4.4 K and superfluid at 1.9 K. Conductors in general are less stable at the lower temperature when measured at the same fraction of critical current. Results show that the cored-cables, even when partially filled with solder or with a 'porous-metal' filler exhibit a relatively low stability at currents close to the critical current. It is speculated that the high inter-strand electrical and thermal resistance inherent in these cables may affect the stability at high currents. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. CERN, CH-1211 Geneva 23, Switzerland. Oxford Instruments, Oxford, England. RP Ghosh, AK (reprint author), Brookhaven Natl Lab, 902-A, Upton, NY 11973 USA. NR 9 TC 10 Z9 10 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 DEC PY 1998 VL 310 IS 1-4 BP 335 EP 339 DI 10.1016/S0921-4534(98)00484-5 PG 5 WC Physics, Applied SC Physics GA 152YT UT WOS:000077806200062 ER PT J AU Zheng, H Jiang, M Nikolova, R Vlasko-Vlasov, V Welp, U Veal, BW Crabtree, GW Claus, H AF Zheng, H Jiang, M Nikolova, R Vlasko-Vlasov, V Welp, U Veal, BW Crabtree, GW Claus, H TI Magnetization and magnetic levitation of ring samples made of melt textured YBa2Cu3Ox SO PHYSICA C LA English DT Article DE magnetization; levitation forces; YBa2Cu3Ox ID SUPERCONDUCTOR; GROWTH; YBACUO AB We present measurements of the magnetization and the levitation force of various superconducting rings made of melt textured YBa2Cu3Ox. We compare the measurements on the rings to those when a slit is cut into them. The slit prevents shielding currents from forming complete loops around the perimeter of the rings. For most small rings used for the magnetization measurements (5 mm diameter or less), the slit reduces the magnetization according to Bean's model. For some rings, however, this decrease was much smaller that the theoretical value. Consistently, however, magneto-optical images revealed the presence of weak, links cutting across those rings. The larger rings used for the levitation experiments (20 mm diameter) were not of the same quality, i.e., the ratio of the levitation force before and after the slit was cut was below the theoretical value for all rings investigated. Because of their large size, magneto-optical images of those rings could not be taken. It is very likely that these larger rings have weak links which prevent large-diameter circulating shielding currents. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Mat Sci Div 223, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Claus, H (reprint author), Argonne Natl Lab, Mat Sci Div 223, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 8 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD DEC 1 PY 1998 VL 309 IS 1-2 BP 17 EP 24 DI 10.1016/S0921-4534(98)00573-5 PG 8 WC Physics, Applied SC Physics GA 145GP UT WOS:000077362900003 ER PT J AU Trabert, E Beiersdorfer, P Utter, SB Lopez-Urrutia, JRC AF Trabert, E Beiersdorfer, P Utter, SB Lopez-Urrutia, JRC TI Forbidden transitions in the visible spectra of an electron beam ion trap (EBIT) SO PHYSICA SCRIPTA LA English DT Article ID MAGNETIC-DIPOLE TRANSITION; HIGHLY-CHARGED IONS; ISOELECTRONIC SEQUENCE; LIFETIME MEASUREMENTS; LINES; KR; CONFIGURATIONS; PROBABILITIES; MOLYBDENUM; XE32+ AB In an explorative study of visible spectra from an electron beam ion trap (EBIT), a variety of rare-gas ion species has been excited and stored. The spectra reveal several forbidden lines and also show peculiarities of general interest to EBIT users. The lifetime of the 3s(2)3p(2) P-3(2) level in Si-like Kr22+ has been measured as [(6.3 +/- 0.3)ms]. The M1 transition 3s(2)3p(2) P-3(1)-P-3(2) in the Si-like ion Mo28+ has been observed at (284.0 +/- 0.2) M1, confirming an identification from tokamak observations by Denne et al. The 3d(4) D-5(2)-D-5(3) transition in Ti-like Au has been found at (353.2 +/- 0.2)nm and thus the predicted isoelectronic trend been confirmed. C1 Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94501 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. RP Trabert, E (reprint author), Univ Calif Lawrence Livermore Natl Lab, Dept Phys & Space Technol, Livermore, CA 94501 USA. EM Traebert@ep3.ruhr-uni.bochum.de RI Crespo Lopez-Urrutia, Jose R./F-7069-2011 OI Crespo Lopez-Urrutia, Jose R./0000-0002-2937-8037 NR 35 TC 37 Z9 37 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 DEC PY 1998 VL 58 IS 6 BP 599 EP 604 DI 10.1088/0031-8949/58/6/009 PG 6 WC Physics, Multidisciplinary SC Physics GA 149AQ UT WOS:000077584100009 ER PT J AU Walukiewicz, W Dubon, OD Silvestri, HH Haller, EE AF Walukiewicz, W Dubon, OD Silvestri, HH Haller, EE TI Hole transport in the upper Hubbard band in Cu-doped germanium under uniaxial pressure SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 8th International Conference on Shallow-Level Centres in Semiconductors (SLCS-(*) CY JUL 27-30, 1998 CL MONTPELLIER, FRANCE ID TRANSITION; SILICON AB The ground state of substitutional Cu in Ge undergoes a transformation from a highly localized 1s(3) to a much more extended 1s(2)2s(1) configuration at the uniaxial pressure of 0.42 GPa along the [100] direction. The transformation is associated with a dramatic reduction of the resistivity. The observed metal-insulator transition is explained with the formation of extended Hubbard bands well separated from the valence band. It is shown that the hole mobility in the upper Hubbard band is limited by scattering from ionized and neutral Cu centers in the delocalized 1s(2)2s(1) configuration. The concentration of the scattering centers and thus also the hole mobility can be controlled by uniaxial pressure. Hole mobilities as high as 10(7) cm(2)/Vs have been observed at 16 K for intermediate uniaxial stresses. These results indicate a very weak coupling between acoustic phonons and the holes in the upper Hubbard band. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Walukiewicz, W (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM wwladek@mh1.lbl.gov NR 24 TC 1 Z9 1 U1 1 U2 1 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD DEC PY 1998 VL 210 IS 2 BP 253 EP 262 DI 10.1002/(SICI)1521-3951(199812)210:2<253::AID-PSSB253>3.0.CO;2-0 PG 10 WC Physics, Condensed Matter SC Physics GA 149LU UT WOS:000077607400005 ER PT J AU Kim, H Vogelgesang, R Ramdas, AK Rodriguez, S Grimsditch, M Anthony, TR AF Kim, H Vogelgesang, R Ramdas, AK Rodriguez, S Grimsditch, M Anthony, TR TI Infrared and Raman spectroscopy of acceptor-bound holes: Boron acceptors in isotopically controlled "blue" diamonds SO PHYSICA STATUS SOLIDI B-BASIC RESEARCH LA English DT Article; Proceedings Paper CT 8th International Conference on Shallow-Level Centres in Semiconductors (SLCS-(*) CY JUL 27-30, 1998 CL MONTPELLIER, FRANCE ID SEMICONDUCTING DIAMOND; GERMANIUM; SPECTRA AB The extremely rare, nitrogen-free, boron-doped diamonds display a Lyman spectrum in the infrared associated with a substitutional group III acceptor. The Lyman spectrum reveals a unique ex ample of "self-energy" corrections to the effective mass theory for the same substitutional acceptor but located in a host differing merely in its isotopic composition. The Lyman spectrum, observed as a function of temperature, shows the existence of a close pair of Is ground states separated by approximate to 2 meV. The electronic Raman spectrum discloses a line at 2.07(1) meV in natural and 2.01(1) meV in C-13 diamonds corresponding to the transition between the spin-orbit split 1s(p(3/2)) and 1s(p(1/2)) ground states. Polarization features show the transition to be dominantly Gamma(5) in character, placing an upper limit on the ratio of the non-spherical Luttinger parameters of the valence band; Zeeman and piezospectroscopic effects fully support the assignment. C1 Purdue Univ, Dept Phys, W Lafayette, IN 47907 USA. Argonne Natl Lab, Argonne, IL 60439 USA. GE Corp Res & Dev, Schenectady, NY 12309 USA. RP Kim, H (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 28 TC 1 Z9 1 U1 1 U2 3 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0370-1972 J9 PHYS STATUS SOLIDI B JI Phys. Status Solidi B-Basic Res. PD DEC PY 1998 VL 210 IS 2 BP 451 EP 458 DI 10.1002/(SICI)1521-3951(199812)210:2<451::AID-PSSB451>3.0.CO;2-0 PG 8 WC Physics, Condensed Matter SC Physics GA 149LU UT WOS:000077607400035 ER PT J AU Woitke, O Djuric, N Dunn, GH Bannister, ME Smith, ACH Wallbank, B Badnell, NR Pindzola, MS AF Woitke, O Djuric, N Dunn, GH Bannister, ME Smith, ACH Wallbank, B Badnell, NR Pindzola, MS TI Absolute cross sections for excitation of the 2s S-2 -> 2p P-2 transition in B2+ and for electron-impact single ionization of B2+ SO PHYSICAL REVIEW A LA English DT Article ID LI-LIKE IONS; R-MATRIX; COUPLING METHOD; HYDROGEN; SCATTERING; CONTINUUM; ENERGY; BEAMS AB Absolute cross sections for electron-impact excitation of the 2s S-2-->2p P-2 transition of B2+ measured between 5.4 and 7.0 eV are presented. The results are in good agreement with the R-matrix-with-pseudostates (RMPS) calculation of Marchalant et al. [J. Phys. B 30, L435 (1997)]. Also presented are cross sections for electron-impact single ionization of B2+, including measurements between 25 and 200 eV and calculations using the RMPS and time-dependent close-coupling methods. The measured ionization cross sections are about 14% higher near the peak than previous measurements by Crandall er nl. [Phys. Rev. A 34, 1757 (1986)], but agree well with experimental data of Hofmann et al. [Z. Phys. D 16, 113 (1990)] and with the present and other theoretical predictions. [S1050-2947(98)01212-8]. 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. UCL, Dept Phys & Astron, London WC1E 6BT, England. St Francis Xavier Univ, Dept Phys, Antigonish, NS B2G 2W5, Canada. Univ Strathclyde, Dept Phys & Appl Phys, Glasgow G4 0NG, Lanark, Scotland. Auburn Univ, Dept Phys, Auburn, AL 36849 USA. RP Univ Colorado, Joint Inst Lab Astrophys, Boulder, CO 80309 USA. NR 29 TC 26 Z9 26 U1 0 U2 1 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 DEC PY 1998 VL 58 IS 6 BP 4512 EP 4517 DI 10.1103/PhysRevA.58.4512 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700036 ER PT J AU Keating, PB Gulley, MS Bryant, HC MacKerrow, EP Miller, WA Rislove, DC Cohen, S Donahue, JB Fitzgerald, DH Funk, DJ Frankle, SC Hutson, RL Macek, RJ Plum, MA Stanciu, NG van Dyck, OB Wilkinson, CA AF Keating, PB Gulley, MS Bryant, HC MacKerrow, EP Miller, WA Rislove, DC Cohen, S Donahue, JB Fitzgerald, DH Funk, DJ Frankle, SC Hutson, RL Macek, RJ Plum, MA Stanciu, NG van Dyck, OB Wilkinson, CA TI H-0 (n = 3,4) Stark states produced in the interaction of 800-MeV H- ions with thin foils SO PHYSICAL REVIEW A LA English DT Article ID RYDBERG STATES AB The interaction of 800-MeV H- ions with a thin foil produces protons, the ground state and excited states of neutral H-0 atoms, and unstripped H- ions. We investigated the distributions of individual H-0 Stark states within the n=3 and 4 levels produced by C and Al2O3 foil stripping of H- ions. Foils of various thicknesses were placed upstream of a magnet with a linearly increasing transverse field along the beam direction producing a motional electric field strong enough to ionize H-0 states with n greater than or equal to 3. We consider three questions: (i) What are the populations of individual H-0 Stark states produced in the interaction of 800-MeV H- ions with thin C and Al2O3 foils, (ii) how do the relative population distributions change with foil thickness, and (iii) how is the population distribution produced in an Al2O3 foil modified when the foil is placed in a magnetic field? A simple qualitative model is presented to explain the major trends. [S1050-2947(98)02212-4]. C1 Univ New Mexico, Albuquerque, NM 87131 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Phys Sci Inc, New England Business Ctr 20, Andover, MA 01810 USA. RP Keating, PB (reprint author), Univ New Mexico, Albuquerque, NM 87131 USA. NR 23 TC 8 Z9 8 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 DEC PY 1998 VL 58 IS 6 BP 4526 EP 4538 DI 10.1103/PhysRevA.58.4526 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700038 ER PT J AU Chen, MH Reed, KJ Guo, DS Savin, DW AF Chen, MH Reed, KJ Guo, DS Savin, DW TI Dielectronic recombination for boronlike ions SO PHYSICAL REVIEW A LA English DT Article ID TIME-RESOLVED SPECTROSCOPY; IONIZATION EQUILIBRIUM; TOKAMAK PLASMAS; RATES; COEFFICIENTS; SELENIUM AB We have calculated the total dielectronic recombination (DR) coefficients for the P-2(1/2) and P-2(3/2) states in B-like Ti17+, Fe21+, and Mo37+ ions for electron temperatures 0.1 less than or equal to T less than or equal to 10 000 eV. The calculations are carried out using the multiconfiguration Dirac-Fock method in intermediate coupling with a configuration interaction. We find that accurate Coster-Kronig energies are critical for a successful determination of low-temperature DR coefficients. We also find that the DR involving fine-structure excitations can be as important as the 2s-2p excitation channels in the low-temperature regime for some ions. [S1050-2947(98)02612-2]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. So Univ, Dept Phys, Baton Rouge, LA 70813 USA. A&M Coll, Baton Rouge, LA 70813 USA. Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA. RP Chen, MH (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. RI Savin, Daniel/B-9576-2012 OI Savin, Daniel/0000-0002-1111-6610 NR 24 TC 11 Z9 11 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 DEC PY 1998 VL 58 IS 6 BP 4539 EP 4547 DI 10.1103/PhysRevA.58.4539 PG 9 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700039 ER PT J AU Walkup, JR Dunn, M Watson, DK Germann, TC AF Walkup, JR Dunn, M Watson, DK Germann, TC TI Avoided crossings of diamagnetic hydrogen as functions of magnetic field strength and angular momentum SO PHYSICAL REVIEW A LA English DT Article ID DIMENSIONAL PERTURBATION-THEORY; CIRCULAR RYDBERG STATES; LARGE-N EXPANSIONS; POTENTIAL SCATTERING; DENSITY FUNCTIONALS; EXCEPTIONAL POINTS; 1/D EXPANSION; WAVE-PACKETS; ATOM; SPECTRA AB The energy levels of diamagnetic hydrogen as a function of two independent parameters, magnetic field strength B, and angular momentum m, are examined. Avoided crossings appear between these energy levels as either parameter is varied while the other is held fixed. These avoided crossings are directly related to degeneracies (Fermi resonances) occurring at zeroth order in perturbation theory. The mathematical basis of these degeneracies are the square-root branch points that connect the energy levels. It is found that the locations of avoided crossings in either constant-B or constant-in spectra can be predicted by visually scanning the locations of these branch points in the complex-delta plane, where delta= 1/(2 + 2 \m\) is the perturbation parameter used in this research. [S1050-2947(98)07111-X]. C1 Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. Univ Calif Los Alamos Natl Lab, Theoret Div T 11, Los Alamos, NM 87545 USA. RP Walkup, JR (reprint author), Univ Oklahoma, Dept Phys & Astron, Norman, OK 73019 USA. NR 85 TC 16 Z9 16 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD DEC PY 1998 VL 58 IS 6 BP 4668 EP 4682 DI 10.1103/PhysRevA.58.4668 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700053 ER PT J AU Yatsenko, LP Guerin, S Halfmann, T Bohmer, K Shore, BW Bergmann, K AF Yatsenko, LP Guerin, S Halfmann, T Bohmer, K Shore, BW Bergmann, K TI Stimulated hyper-Raman adiabatic passage. I. The basic problem and examples SO PHYSICAL REVIEW A LA English DT Article ID POPULATION TRANSFER AB We discuss various theoretical issues that arise when one extends the conventional stimulated Raman adiabatic passage, involving a pump pulse preceded by a Stokes pulse, to situations in which the pump interaction involves a two-photon transition. As in the simpler cases, it is possible to obtain complete population transfer between an initial state and a targeted final state, if certain general conditions on the pulses are met. We point out important considerations, associated with dynamic Stark shifts and multiphoton ionization, which make successful population transfer more difficult in the multiphoton extension. We illustrate these problems and requirements by considering specific examples of excitation in metastable helium. [S1050-2947(98)09211-7]. C1 Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. Natl Acad Sci Ukraine, Inst Phys, Kiev 22, Ukraine. Univ Bourgogne, CNRS, Phys Lab, F-21011 Dijon, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Yatsenko, LP (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 8 TC 40 Z9 41 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 DEC PY 1998 VL 58 IS 6 BP 4683 EP 4690 DI 10.1103/PhysRevA.58.4683 PG 8 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700054 ER PT J AU Guerin, S Yatsenko, LP Halfmann, T Shore, BW Bergmann, K AF Guerin, S Yatsenko, LP Halfmann, T Shore, BW Bergmann, K TI Stimulated hyper-Raman adiabatic passage. II. Static compensation of dynamic Stark shifts SO PHYSICAL REVIEW A LA English DT Article ID COHERENT POPULATION TRANSFER; 3-LEVEL SYSTEM DRIVEN; DELAYED LASER-PULSES; MULTILEVEL SYSTEMS; MAGNETIC SUBLEVELS; SCATTERING AB When one extends the conventional stimulated Raman adiabatic passage method of population transfer; involving a pump pulse preceded by a Stokes pulse, to situations in which the pump (or pump and Stokes) interaction involves a two-photon transition, there occur unavoidable dynamic Stark shifts which prevent maintenance of the relevant resonance conditions. Such shifts can prevent the desired population transfer. We show, through numerical modeling and analytic considerations, that the detrimental effects of dynamic shifts can be compensated by a suitable choice of (static) detunings of the carrier frequencies of the two pulses, so that population transfer can be achieved. We present simple analytic expressions for bounding the range of detunings for which population transfer can occur, and we present numerical results supporting the simple picture of the two-step linewidth. We illustrate these remarks by considering specific examples. [S1050-2947(98)09311-1]. C1 Univ Kaiserslautern, Fachbereich Phys, D-67653 Kaiserslautern, Germany. Univ Bourgogne, CNRS, Phys Lab, F-21011 Dijon, France. Natl Acad Sci Ukraine, Inst Phys, Kiev 22, Ukraine. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Guerin, S (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 10 TC 36 Z9 36 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 DEC PY 1998 VL 58 IS 6 BP 4691 EP 4704 DI 10.1103/PhysRevA.58.4691 PG 14 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA 145CD UT WOS:000077352700055 ER PT J AU Kopidakis, G Wang, CZ Soukoulis, CM Ho, KM AF Kopidakis, G Wang, CZ Soukoulis, CM Ho, KM TI Hydrogen-induced structural changes in tetrahedral amorphous carbon SO PHYSICAL REVIEW B LA English DT Article ID TIGHT-BINDING MODEL; EQUILIBRIUM STRUCTURE; MICROSCOPIC STRUCTURE; ELECTRONIC-PROPERTIES; NEUTRON-SCATTERING; MOLECULAR-DYNAMICS; METHANE; SILICON AB The influence of hydrogen on the structure and properties of tetrahedral amorphous carbon (ta-C) is studied by tight-binding molecular-dynamics simulations. The results show that hydrogen tends to break carbon-carbon bands in ta-C. Reduction of C-C coordinations makes ta-C softer and introduces more electronic states in the energy-gap region, [S0163-1829(98)00945-X]. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Kopidakis, G (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RI Soukoulis, Costas/A-5295-2008 NR 27 TC 12 Z9 12 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 DEC 1 PY 1998 VL 58 IS 21 BP 14106 EP 14109 DI 10.1103/PhysRevB.58.14106 PG 4 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000005 ER PT J AU Klemm, RA Arnold, G Rieck, CT Scharnberg, K AF Klemm, RA Arnold, G Rieck, CT Scharnberg, K TI Coherent versus incoherent c-axis Josephson tunneling between layered superconductors SO PHYSICAL REVIEW B LA English DT Article ID BOUNDARIES; STATE AB We calculate I-c( T) and R-n for both coherent and incoherent electron tunneling across a c-axis break junction between two nu=s,d(x2-y2)-wave layered superconducting half spaces, each with c-axis bandwidth 2J. Coherent quasiparticle tunneling only occurs for voltages V<2J/e, leading to difficulties in measuring R-n for under-doped samples. The coherent part of I-c(0) is independent of Delta(nu)(0) for J/Delta(nu)(0)much less than 1, and can be large. Our results are discussed with regard to recent experiments. [S0163-1829(98)01745-7]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 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 18 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 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 21 BP 14203 EP 14206 DI 10.1103/PhysRevB.58.14203 PG 4 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000030 ER PT J AU Kim, DH Park, JH Kim, YH Lee, JM Hahn, TS Hettinger, JD Miller, DJ Gray, KE AF Kim, DH Park, JH Kim, YH Lee, JM Hahn, TS Hettinger, JD Miller, DJ Gray, KE TI Angular dependence of the Hall conductivity in YBa2Cu3Ox films with columnar defects SO PHYSICAL REVIEW B LA English DT Article ID PINNING STRENGTH DEPENDENCE; MIXED-STATE; VORTICES PARALLEL; SCALING BEHAVIOR; CUO2 LAYERS; TRANSPORT-PROPERTIES; SUPERCONDUCTORS; CRYSTALS; ORIGIN; RESISTIVITY AB We have studied the role of strong pinning on the Hall conductivity by measuring the angular dependence of the longitudinal and the Hall resistivity of YBa2Cu3Ox films with columnar defects. The resulting Hall conductivity \sigma(xy)\ of irradiated films shows a sharp increase with decreasing temperature when an external magnetic field is aligned parallel to the columnar defects, a strong pinning configuration, whereas \sigma(xy)\ of unirradiated films shows a broad minimum in the same orientation. This distinctive difference demonstrates the pinning dependence of the Hall conductivity; [S0163-1829(98)04446-4]. C1 Yeungnam Univ, Dept Phys, Kyongsan 712749, South Korea. Korea Inst Sci & Technol, Seoul 136791, South Korea. Argonne Natl Lab, Argonne, IL 60439 USA. RP Kim, DH (reprint author), Yeungnam Univ, Dept Phys, Kyongsan 712749, South Korea. NR 17 TC 3 Z9 3 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 DEC 1 PY 1998 VL 58 IS 21 BP 14215 EP 14218 DI 10.1103/PhysRevB.58.14215 PG 4 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000033 ER PT J AU Dimitrov, DA Ankudinov, AL Bishop, AR Conradson, SD AF Dimitrov, DA Ankudinov, AL Bishop, AR Conradson, SD TI Pair distribution function and x-ray absorption signatures of rotational and radial local distortions in a model system with average long-range order SO PHYSICAL REVIEW B LA English DT Article ID MULTIPLE-SCATTERING CALCULATIONS; PULSED-NEUTRON-DIFFRACTION; RANDOM SOLID-SOLUTIONS; FINE-STRUCTURE; CUO2 PLANE; COLOSSAL-MAGNETORESISTANCE; STRIPE STRUCTURE; LATTICE; SUPERCONDUCTORS; TC AB The signatures of local distortions in three-dimensional crystalline structures are studied by calculating extended x-ray absorption fine structure (EXAFS) spectra and pair distribution functions (PDF) from a binary system with several different concentrations of randomly distributed radial, rotational, or buckling static distortions. The PDF and EXAFS are examined to determine if unique signatures for the different distortion scan be obtained. It is shown how the complementarity of the PDF and EXAFS data can be used to effectively separate the radial from the rotational local distortions. [S0163-1829(98)04445-2]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Dimitrov, DA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 46 TC 10 Z9 10 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 DEC 1 PY 1998 VL 58 IS 21 BP 14227 EP 14237 DI 10.1103/PhysRevB.58.14227 PG 11 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000036 ER PT J AU Balakrishnan, R Saxena, A AF Balakrishnan, R Saxena, A TI Energy structure of curved magnetic surfaces and its relationship with geometric phase SO PHYSICAL REVIEW B LA English DT Article AB We show that the energy H of a Heisenberg ferromagnetic spin system on curved surfaces satisfies the inequality H greater than or equal to\Gamma\ where Gamma is a certain geometric phase associated with the spin vector field. We solve the variational equation delta H=0 exactly, for a wide class of surfaces to find soliton lattice solutions in terms of a geometry-dependent parameter. Both H and Gamma develop two branches each, which all merge at the one-soliton limit. This branching is a signature of a topological transition in the system. An analogous branching (of time periods) also occurs in a dynamical system, when there is a change in topology of phase trajectories. [S0163-1829(98)00345-2]. C1 Inst Math Sci, Madras 600113, Tamil Nadu, India. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Balakrishnan, R (reprint author), Inst Math Sci, Madras 600113, Tamil Nadu, India. NR 14 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 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 21 BP 14383 EP 14386 DI 10.1103/PhysRevB.58.14383 PG 4 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000053 ER PT J AU Yokoo, T Raymond, S Zheludev, A Maslov, S Ressouche, E Zaliznyak, I Erwin, R Nakamura, M Akimitsu, J AF Yokoo, T Raymond, S Zheludev, A Maslov, S Ressouche, E Zaliznyak, I Erwin, R Nakamura, M Akimitsu, J TI Magnetic ordering, spin waves, and Haldane-gap excitations in (NdxY1-x)(2)BaNiO5 linear-chain mixed-spin antiferromagnets SO PHYSICAL REVIEW B LA English DT Article ID ONE-DIMENSIONAL ANTIFERROMAGNETS; SOFT-MODE TRANSITION; NEUTRON-SCATTERING; MONTE-CARLO; FIELD; ND2BANIO5; Y2BANIO5; NENP; DIFFRACTION; PR2BANIO5 AB Linear-chain nickelates with the composition (NdxY1-x)(2)BaNiO5 (x = 1, x = 0.75, x = 0.5, and x = 0.25) are studied in a series of neutron-scattering experiments. Powder diffraction is used to determine the temperature dependence of the magnetic structure in all four systems. Single-crystal inelastic neutron scattering is employed to investigate the temperature dependence of the Haldane-gap excitations and low-energy spin waves in the x= 1 compound Nd2BaNiO5. The results of these experiments are discussed in the context of the "Haldane chain in a staggered field" model for R2BaNiO5 systems, and quantitative agreement with theory is obtained. [SO163-1829(98)07945-4]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. CEN, MDN, SPSMS, DRFMC, F-38054 Grenoble, France. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 157, Japan. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. PL Kapitza Phys Problems Inst, Moscow, Russia. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI Zaliznyak, Igor/E-8532-2014; Maslov, Sergei/C-2397-2009 OI Zaliznyak, Igor/0000-0002-9886-3255; Maslov, Sergei/0000-0002-3701-492X NR 47 TC 41 Z9 41 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 21 BP 14424 EP 14435 DI 10.1103/PhysRevB.58.14424 PG 12 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000059 ER PT J AU von Ranke, PJ Pecharsky, VK Gschneidner, KA Korte, BJ AF von Ranke, PJ Pecharsky, VK Gschneidner, KA Korte, BJ TI Anomalous behavior of the magnetic entropy in PrNi5 SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL-FIELD AB By considering a Hamiltonian that includes the crystalline electric field and exchange interaction components we showed theoretically that paramagnetic PrNi5 exhibits an anomalous entropy behavior in which the magnetic entropy increases with increasing magnetic field at low temperature. This anomaly in magnetic entropy can be fully understood and is associated with the crossing of the two lowest magnetic energy levels (Gamma(4) and Gamma(1)). Experimental verification of the anomalous behavior of the magnetic entropy in polycrystalline PrNi5 was obtained. [S0163-1829 (98)02045-1]. 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. Univ Estado Rio De Janeiro, IF, BR-20550013 Rio De Janeiro, Brazil. RP von Ranke, PJ (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 14 TC 50 Z9 50 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 DEC 1 PY 1998 VL 58 IS 21 BP 14436 EP 14441 DI 10.1103/PhysRevB.58.14436 PG 6 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000060 ER PT J AU de Bernabe, A Cuello, GJ Bermejo, FJ Trouw, FR Jansen, APJ AF de Bernabe, A Cuello, GJ Bermejo, FJ Trouw, FR Jansen, APJ TI Vibrational dynamics in solid alpha-oxygen: Experimental assessment of spin-phonon couplings SO PHYSICAL REVIEW B LA English DT Article ID CONDENSED OXYGEN; BETA-OXYGEN; THERMAL-CONDUCTIVITY; NEUTRON-SCATTERING; MAGNETIC-STRUCTURE; HIGH-PRESSURE; TRANSITION; FIELDS; PHASE AB The dynamics of ct-oxygen is investigated by means of high-resolution inelastic neutron scattering. The generalized frequency distribution for vibrational motions is derived from the large-angle spectra. A comparison of spectra on both sides of the alpha-->beta magnetic ordering transition provides a clear indication of the extent of the coupling between the magnetic and lattice degrees of freedom. The specific heat and vibrational mean-square amplitudes are calculated from the spectra and compared with experimental and ab initio results. The latter also aids with the assignment of the spectral Features, and to reconcile the present observations with previous measurements. [S0163-1829(98)07045-3]. C1 CSIC, E-28006 Madrid, Spain. Argonne Natl Lab, Argonne, IL 60439 USA. Eindhoven Univ Technol, Inorgan Chem & Catalysis Lab, NL-5600 MB Eindhoven, Netherlands. RP de Bernabe, A (reprint author), CSIC, Serrano 123, E-28006 Madrid, Spain. RI Cuello, Gabriel/C-5831-2009 OI Cuello, Gabriel/0000-0003-3844-0602 NR 55 TC 6 Z9 6 U1 0 U2 3 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 21 BP 14442 EP 14451 DI 10.1103/PhysRevB.58.14442 PG 10 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000061 ER PT J AU Grimsditch, M McNeil, LE Lockwood, DJ AF Grimsditch, M McNeil, LE Lockwood, DJ TI Unexpected behavior of the antiferromagnetic mode of NiO SO PHYSICAL REVIEW B LA English DT Article ID RAMAN-SCATTERING; 2-MAGNON AB Although NiO is often considered the classic example of an antiferromagnetic insulator, recent investigations have revealed unexplained features of the magnon spectrum. The present study of the temperature and polarization behavior of first-order magnetic Raman scattering reveals that the polarization selection rules are not described by the generally accepted antisymmetric scattering tensor. The inclusion of quadratic magnetooptic coupling terms can explain the symmetry of the scattering tensor, but does not lead to results consistent with the accepted [112] spin alignment direction. [S0163-1829(98)06241-9]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ N Carolina, Dept Phys & Astron, Chapel Hill, NC 27599 USA. Natl Res Council Canada, Inst Microstruct Sci, Ottawa, ON K1A 0R6, Canada. RP Grimsditch, M (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 26 Z9 26 U1 2 U2 9 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 DEC 1 PY 1998 VL 58 IS 21 BP 14462 EP 14466 DI 10.1103/PhysRevB.58.14462 PG 5 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000064 ER PT J AU Choudhury, DP Srikanth, H Sridhar, S Canfield, PC AF Choudhury, DP Srikanth, H Sridhar, S Canfield, PC TI Magnetoelectrodynamics at high frequencies in the antiferromagnetic and superconducting states of DyNi2B2C SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTAL; MICROWAVE RESPONSE; PENETRATION DEPTH; CRITICAL FIELDS; MAGNETISM; ORDER; TRANSITIONS; DEPENDENCE; ANISOTROPY; INTERPLAY AB We report our observation of the behavior of the radio frequency (rf) and microwave response of DyNi2B2C over a wide range of temperature (T) and magnetic field (H) in the antiferromagnetic (AFM) and superconducting (SC) states. At microwave frequencies of 10 GHz, the T dependence of the surface impedance Z(s) = R-s+ iX(s) was measured which yields the T dependence of the complex conductivity sigma(1) - i sigma(2) in the SC and AFM states. At radio frequencies (4 MHz), the H and T dependence of the penetration depth lambda(T,H) were measured. The establishment of antiferromagnetic order at T-N = 10.3 K results in a marked decrease in the scattering of charge carriers, leading to sharp decreases in R-s and X-s. However, R-s and X-s differ from each other in the AFM state. We show that the results are consistent with relaxation processes whence the scattering rate becomes comparable to the microwave frequency. The rf measurements yield a rich dependence of the scattering on the magnetic field near and below T-N. Anomalous decrease of scattering at moderate applied fields is observed at temperatures near and above T-N, and arises due to a crossover from a negative magnetoresistance state, possibly associated with a loss of spin disorder scattering at low fields, to a positive magnetoresistance state associated with the metallic nature. The normal state magnetoresistance is positive at all temperatures for mu(0)H>2 T and at all fields for T> 15 K. Several characteristic field scales associated with metamagnetic: transitions [H-M1(T),H-M2(T)], the onset of spin disorder H-D(T) and The upper critical field H-c2(T) are observed in the rf measurements. [S0163-1829 (98)04342-2]. C1 Northeastern Univ, Dept Phys, Boston, MA 02115 USA. USAF, Res Lab, Bedford, MA 01730 USA. Iowa State Univ Sci & Technol, Ames Lab, Dept Phys & Astron, Ames, IA 50011 USA. RP Choudhury, DP (reprint author), Northeastern Univ, Dept Phys, Boston, MA 02115 USA. RI Sridhar, Srinivas/A-3688-2012; Canfield, Paul/H-2698-2014 NR 50 TC 6 Z9 6 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 DEC 1 PY 1998 VL 58 IS 21 BP 14490 EP 14497 DI 10.1103/PhysRevB.58.14490 PG 8 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000069 ER PT J AU Aranson, IS Scheidl, S Vinokur, VM AF Aranson, IS Scheidl, S Vinokur, VM TI Nonequilibrium dislocation dynamics and instability of driven vortex lattices in two dimensions SO PHYSICAL REVIEW B LA English DT Article ID MOVING GLASS PHASE; SPIRAL WAVES; SYSTEMS; MEDIA; ORDER; DEFECTS AB We consider dislocations in a vortex lattice that is driven in a two-dimensional superconductor with random impurities. The structure and dynamics of dislocations are studied in this genuine nonequilibrium situation on the basis of a coarse-grained equation of motion for the displacement field. The presence of dislocations leads to a characteristic anisotropic distortion of the vortex density that is controlled by a Kardar-Parisi-Zhang nonlinearity in the coarse-grained equation of motion. This nonlinearity also implies a screening of the interaction between dislocations and thereby an instability of the vortex lattice to the proliferation of free dislocations. [S0163-1829(98)02342-X]. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Univ Cologne, Inst Theoret Phys, D-50937 Cologne, Germany. RP Aranson, IS (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Aranson, Igor/I-4060-2013 NR 31 TC 18 Z9 18 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 DEC 1 PY 1998 VL 58 IS 21 BP 14541 EP 14547 DI 10.1103/PhysRevB.58.14541 PG 7 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000075 ER PT J AU Nordborg, H Blatter, G AF Nordborg, H Blatter, G TI Numerical study of vortex matter using the Bose model: First-order melting and entanglement SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TC SUPERCONDUCTORS; HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTAL YBA2CU3O7; UNIVERSAL PHASE-DIAGRAM; ONE-COMPONENT PLASMA; MONTE-CARLO; LAYERED SUPERCONDUCTORS; LONGITUDINAL SUPERCONDUCTIVITY; ANISOTROPIC SUPERCONDUCTORS; UNTWINNED YBA2CU3O7-DELTA AB We present an extensive numerical study of vortex matter using the mapping to two-dimensional bosons and path-integral Monte Carlo simulations. We find a first-order vortex lattice melting transition into an entangled vortex liquid. The jumps in entropy and density are consistent with experimental results on YBa2Cu3O7-delta. The liquid is denser than the lattice and has a correlation length l(z) approximate to 1.7 epsilon a(0) in the direction parallel to the held. In the language of bosons we find a sharp quantum phase transition from a Wigner crystal to a superfluid, even in the case of logarithmic interaction. We also measure the excitation spectrum of the Bose system and find the roton minimum to be insensitive to the range of the interaction. [S0163-1829(98)02246-2]. C1 ETH Honggerberg, CH-8093 Zurich, Switzerland. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60469 USA. RP Nordborg, H (reprint author), ETH Honggerberg, CH-8093 Zurich, Switzerland. OI Nordborg, Henrik/0000-0003-3432-3257 NR 69 TC 30 Z9 30 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 DEC 1 PY 1998 VL 58 IS 21 BP 14556 EP 14571 DI 10.1103/PhysRevB.58.14556 PG 16 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000077 ER PT J AU Kwok, WK Paulius, LM Vinokur, VM Petrean, AM Ronningen, RM Crabtree, GW AF Kwok, WK Paulius, LM Vinokur, VM Petrean, AM Ronningen, RM Crabtree, GW TI Anisotropically splayed and columnar defects in untwinned YBa2Cu3O7-delta SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTAL YBA2CU3O7-DELTA; LATTICE-MELTING TRANSITION; HIGH-TC SUPERCONDUCTORS; VORTEX-LIQUID-STATE; 0.8 GEV PROTONS; CU-O CRYSTALS; BOSON LOCALIZATION; ION IRRADIATION; ENHANCEMENT AB Pinning by splayed and columnar defects created by 3.9 GeV (197)AU(29+) ions is investigated using transport measurements of vortex motion perpendicular and parallel to the splay plane in untwinned crystals of YBa2Cu3O7-delta. These results are compared with a sample with parallel columnar defects parallel to the c axis. We report on the temperature, held, and angular dependence of the vortex liquid and solid state. We find that, at twice the matching field, the irreversibility lines for pre- and post-irradiated splayed-defect samples cross. We determine the vortex liquid pinning energy for splayed and columnar defects and show that the barrier to vortex motion perpendicular to the splay plane is greater than that to motion parallel to the splay plane. [S0163-1829(98)01646-4]. C1 Argonne Natl Lab, Mat Sci & Sci & Technol Ctr Superconduct, Argonne, IL 60435 USA. Western Michigan Univ, Dept Phys, Kalamazoo, MI 49008 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. RP Kwok, WK (reprint author), Argonne Natl Lab, Mat Sci & Sci & Technol Ctr Superconduct, Argonne, IL 60435 USA. NR 43 TC 27 Z9 27 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 21 BP 14594 EP 14608 DI 10.1103/PhysRevB.58.14594 PG 15 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000081 ER PT J AU Homes, CC Clayman, BP Peng, JL Greene, RL AF Homes, CC Clayman, BP Peng, JL Greene, RL TI Reply to "Comment on 'Optical properties of Nd1.85Ce0.15CuO4'" SO PHYSICAL REVIEW B LA English DT Article ID CONDUCTORS; SYSTEMS; PHONON AB The nature of the phonon screening is discussed for the cuprate superconductor Nd1.85Ce0.15CuO4 that we have previously examined [Phys. Rev. B 56, 5525 (1997)] in order to reply to the preceding Comment; the implications for phonon assignments are also examined. [S0163-1829(98)03846-6]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Simon Fraser Univ, Dept Phys, Burnaby, BC V5A 1S6, Canada. Univ Maryland, Dept Phys & Astron, Ctr Superconduct Res, College Pk, MD 20742 USA. RP Homes, CC (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 14 TC 0 Z9 0 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 DEC 1 PY 1998 VL 58 IS 21 BP 14623 EP 14624 DI 10.1103/PhysRevB.58.14623 PG 2 WC Physics, Condensed Matter SC Physics GA 144RC UT WOS:000077328000085 ER PT J AU Zvezdin, AK Dobrovitski, VV Harmon, BN Katsnelson, MI AF Zvezdin, AK Dobrovitski, VV Harmon, BN Katsnelson, MI TI Quantum fluctuations in many-spin magnetic molecules SO PHYSICAL REVIEW B LA English DT Article ID CLUSTERS AB If a single spin possessing an easy-axis anisotropy is subjected to an external field perpendicular to the easy axis, the susceptibility exhibits a peculiar peak. We establish that the specific spectral properties of quantum fluctuations give rise to this peak. We predict that this effect takes place in real many-spin systems, such as Mn-12 clusters, and can be studied at finite temperatures in real experiments with attainable resolution. This offers an approach for studying quantum fluctuations in magnetic molecules, in addition to relaxation rate measurements. C1 Russian Acad Sci, Inst Gen Phys, Moscow 117942, Russia. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Russian Acad Sci, Inst Met Phys, Ekaterinburg 620219, Russia. RP Zvezdin, AK (reprint author), Russian Acad Sci, Inst Gen Phys, 38 Vavilov St, Moscow 117942, Russia. RI Katsnelson, Mikhail/D-4359-2012; Zvezdin, Anatoly/K-2072-2013 NR 18 TC 19 Z9 19 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 DEC 1 PY 1998 VL 58 IS 22 BP 14733 EP 14736 PG 4 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000019 ER PT J AU Romero, DB Podobedov, VB Weber, A Rice, JP Mitchell, JF Sharma, RP Drew, HD AF Romero, DB Podobedov, VB Weber, A Rice, JP Mitchell, JF Sharma, RP Drew, HD TI Polarons in the layered perovskite manganite La1.2Sr1.8Mn2O7 SO PHYSICAL REVIEW B LA English DT Article ID COLOSSAL-MAGNETORESISTANCE; GIANT MAGNETORESISTANCE; OXIDES; SUPERCONDUCTIVITY; PHONON; ORDER AB The temperature (6-350 K) and magnetic-field dependence (0-7.5 T) of the phononic Raman spectra in the layered manganites, R1.2Sr1.8Mn2O7 (R = La,Nd), reveal anomalous behaviors of the Mn and equatorial O-xy(Big) modes arising from local octahedral distortions and coupling to the Mn3+ e(g) electrons. These results provide the evidence for polaron formation and its interplay with electrical transport and magnetism in the layered manganites. C1 NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Russian Acad Sci, Inst Spect, Troitsk 142092, Moscow Region, Russia. RP Podobedov, VB (reprint author), NIST, Opt Technol Div, Gaithersburg, MD 20899 USA. NR 21 TC 27 Z9 27 U1 1 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 22 BP 14737 EP 14740 PG 4 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000020 ER PT J AU Yethiraj, M Paul, DM Tomy, CV Thompson, JR AF Yethiraj, M Paul, DM Tomy, CV Thompson, JR TI Square flux lines in YNi2B2C SO PHYSICAL REVIEW B LA English DT Article ID LATTICE; SCATTERING; ERNI2B2C AB Magnetic fields penetrate a type-II superconductor via quantized Bur lines. Why these flux lines sometimes form square arrays, as in YNi2B2C with the field parallel to the c axis, rather than the expected hexagonal ordering, has long fascinated physicists and has eluded a simple explanation. Our latest measurements on YNi2B2C prove conclusively that the London penetration depth within the a-b plane is not isotropic. This anisotropy of the London depths implies that the cross section of an individual flux line has square symmetry, which makes a square lattice energetically favored over the more prosaic hexagonal ordering. [S0163-1829(98)51146-0]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Warwick, Dept Phys, Coventry CV4 7AL, W Midlands, England. Univ Tennessee, Knoxville, TN 37996 USA. RP Yethiraj, M (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 14 TC 13 Z9 13 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD DEC 1 PY 1998 VL 58 IS 22 BP 14767 EP 14770 PG 4 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000028 ER PT J AU Balbach, JJ Conradi, MS Hoffmann, MM Udovic, TJ Adolphi, NL AF Balbach, JJ Conradi, MS Hoffmann, MM Udovic, TJ Adolphi, NL TI Nuclear magnetic resonance evidence of disorder and motion in yttrium trideuteride SO PHYSICAL REVIEW B LA English DT Article ID SWITCHABLE OPTICAL-PROPERTIES; LANTHANUM HYDRIDE FILMS; THEORETICAL PREDICTION; ELECTRONIC-STRUCTURE; HYDROGEN DIFFUSION; INSULATING YH3; METAL-HYDRIDES; NMR; DYNAMICS; SITE AB Three samples of YDx, with x ranging from 2.9 to nearly 3.0, were studied with deuterium nuclear magnetic resonance to gain insight into the locations of the D atoms in the lattice and their motions. Line shapes at low temperatures (200-330 K) show substantial disorder at some of the deuterium sites. Near 355 K, the spectrum sharpens to yield three uniaxial Fake patterns, reflecting a motional averaging process. However, the three measured intensities do not match the ratios expected from the neutron-determined, HoD3-like structure. This is strong evidence that the structure and space group of YD3 are different than reported, or that the current model needs adjustment. At still higher temperatures near 400 K, the Fake doublet features broaden, and a single sharp resonance develops, signalling a diffusive motion that carries all D atoms over all sites. The temperature at which line shape changes occur depends on the number of deuterium vacancies, 3-x. The changes occur at lower temperatures in the most defective sample, indicating the role of D-atom vacancies in the motional processes. The longitudinal relaxation rate T-1(-1) displays two regimes, being nearly temperature independent below 300 K and strongly thermally activated above. The relaxation rate depends on the number of deuterium vacancies, 3-x, varying an order of magnitude over the range of stoichiometries studied and suggesting that D-atom diffusion is involved. Also, the activation energy describing T-1(-1) (similar or equal to k(B)x 5500 K) approximately matches that for diffusion. An unusual omega(0)(-0.7) frequency dependence of T-1(-1) is observed. A relaxation mechanism is proposed in which diffusion is the Pate-determining step and in which frequency dependence arises from a field-dependent radius of the relaxation zones. [S0163-1829(98)07845-X]. C1 NIDDKD, NIH, Bethesda, MD 20892 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. Pacific NW Natl Lab, Richland, WA 99352 USA. NIST, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Knox Coll, Dept Phys, Galesburg, IL 61401 USA. RP Balbach, JJ (reprint author), NIDDKD, NIH, Bethesda, MD 20892 USA. NR 31 TC 20 Z9 20 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 DEC 1 PY 1998 VL 58 IS 22 BP 14823 EP 14832 DI 10.1103/PhysRevB.58.14823 PG 10 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000036 ER PT J AU Goodrich, RG Harrison, N Vuillemin, JJ Teklu, A Hall, DW Fisk, Z Young, D Sarrao, J AF Goodrich, RG Harrison, N Vuillemin, JJ Teklu, A Hall, DW Fisk, Z Young, D Sarrao, J TI Fermi surface of ferromagnetic EuB6 SO PHYSICAL REVIEW B LA English DT Article AB We have determined the Fermi surface and effective masses of electronic carriers in ferromagnetic EuB6 from pulsed field magnetization and steady field torque Landau quantum oscillatory measurements. To aid in the interpretation of the measurements, superconducting quantum interference device magnetometer measurements of the overall magnetization were made on the same samples. The results are consistent with recent electronic structure calculations and show both an electron and a hole pocket located at the X point in the Brillouin zone. [S0163-1829(98)03935-9]. C1 Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Univ Arizona, Dept Phys, Tucson, AZ 85721 USA. Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA. RP Goodrich, RG (reprint author), Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA. NR 19 TC 35 Z9 35 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 DEC 1 PY 1998 VL 58 IS 22 BP 14896 EP 14902 DI 10.1103/PhysRevB.58.14896 PG 7 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000046 ER PT J AU Benkraouda, M Clem, JR AF Benkraouda, M Clem, JR TI Critical current from surface barriers in type-II superconducting strips SO PHYSICAL REVIEW B LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; BI2SR2CACU2O8; CRYSTALS; FLUX; IRREVERSIBILITY; MAGNETIZATION; PENETRATION; RELAXATION AB Extending a model we previously used to calculate magnetization hysteresis arising from the geometrical barrier in a flat, bulk-pinning-free type-II superconducting strip subjected to a perpendicular magnetic field H-a, we here calculate the contribution, arising from screening currents on the top and bottom surfaces, to the magnetic-field-dependent critical current I-c(H-a) due to surface barriers, including both the geometrical barrier and the Bean-Livingston barrier. [S0163-1829(98)04946-7]. C1 UAE Univ, Dept Phys, Al Ain, U Arab Emirates. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Benkraouda, M (reprint author), UAE Univ, Dept Phys, POB 17551, Al Ain, U Arab Emirates. NR 21 TC 62 Z9 63 U1 1 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 DEC 1 PY 1998 VL 58 IS 22 BP 15103 EP 15107 DI 10.1103/PhysRevB.58.15103 PG 5 WC Physics, Condensed Matter SC Physics GA 146XW UT WOS:000077460000068 ER PT J AU Marcucci, LE Riska, DO Schiavilla, R AF Marcucci, LE Riska, DO Schiavilla, R TI Electromagnetic structure of trinucleons SO PHYSICAL REVIEW C LA English DT Article ID MONTE-CARLO CALCULATIONS; FORM-FACTORS; ELASTIC-SCATTERING; EXCHANGE CURRENTS; BINDING-ENERGY; CROSS-SECTION; GROUND-STATE; NUCLEI; POTENTIALS; CHARGE AB The electromagnetic form factors of the trinucleons H-3 and He-3 are calculated with wave functions obtained with the Argonne vis two-nucleon and Urbana IX three-nucleon interactions. Full account is taken of the two-body currents required by current conservation with the upsilon(18) interaction as well as those associated with Na transition currents and the currents of Delta resonance components in the wave functions. Explicit three-nucleon current operators associated with the two-pion exchange three-nucleon interaction arising from irreducible S-wave pion-nucleon scattering are constructed and shown to have very little effect on the calculated magnetic form factors. The calculated magnetic form factor of H-3, and charge form factors of both H-3 and He-3 are in satisfactory agreement with the experimental data. However, the position of the zero in the magnetic form factor of He-3 is slightly underpredicted. [S0556-2813(98)06312-2]. C1 Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Univ Helsinki, Dept Phys, SF-00014 Helsinki, Finland. Jefferson Lab, Newport News, VA 23606 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RP Marcucci, LE (reprint author), Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. NR 44 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3069 EP 3084 DI 10.1103/PhysRevC.58.3069 PG 16 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200009 ER PT J AU Kievsky, A Viviani, M Rosati, S Huber, D Glockle, W Kamada, H Witala, H Golak, J AF Kievsky, A Viviani, M Rosati, S Huber, D Glockle, W Kamada, H Witala, H Golak, J TI Benchmark calculations for polarization observables in three-nucleon scattering SO PHYSICAL REVIEW C LA English DT Article ID NEUTRON-DEUTERON SCATTERING; N-D SCATTERING; MOMENTUM-SPACE; ELASTIC-SCATTERING; MIXING PARAMETERS; BREAKUP THRESHOLD; 3-NUCLEON FORCE; PHASE-SHIFT; POTENTIALS AB High precision benchmark calculations for phase shifts and mixing parameters as well as observables in elastic neutron-deuteron scattering below the deuteron breakup threshold are presented using a realistic nucleon-nucleon potential. Two totally different methods, one using a variational principle in configuration space and the other solving the Faddeev equations in momentum space, are used and compared to each other. The agreement achieved in phase shifts and mixing parameters as well as in the polarization observables is excellent. The extreme sensitivity of the vector analyzing power A(gamma) to small changes of the phase shifts and mixing parameters is pointed out. [S0556-2813(98)07312-9]. C1 Ist Nazl Fis Nucl, I-56100 Pisa, Italy. Univ Pisa, Dipartimento Fis, I-56100 Pisa, Italy. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Ruhr Univ Bochum, Inst Theoret Phys 2, D-44780 Bochum, Germany. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. RP Kievsky, A (reprint author), Ist Nazl Fis Nucl, Piazza Torricelli 2, I-56100 Pisa, Italy. RI kievsky, alejandro/A-7123-2011 NR 23 TC 42 Z9 43 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 DEC PY 1998 VL 58 IS 6 BP 3085 EP 3092 DI 10.1103/PhysRevC.58.3085 PG 8 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200010 ER PT J AU O'Brien, NJ Wadsworth, R Archer, DE Fallon, P Hibbert, IM Joss, DT LaFosse, DR Nolan, PJ Paul, ES Pfohl, J Riley, MA Sarantites, DG Wyss, R AF O'Brien, NJ Wadsworth, R Archer, DE Fallon, P Hibbert, IM Joss, DT LaFosse, DR Nolan, PJ Paul, ES Pfohl, J Riley, MA Sarantites, DG Wyss, R TI Highly deformed structures in Sm-135,Sm-136 SO PHYSICAL REVIEW C LA English DT Article ID SUPERDEFORMED BAND; LIFETIME MEASUREMENTS; LARGE-DEFORMATION; MASS REGION; SPECTROSCOPY; TRANSITIONS; MINIMUM; ND-133; STATES; SM-135 AB High-spin states have been populated in the neutron-deficient Sm-135,Sm-136 nuclei via the Pd-105(Cl-35,pxn) reaction at a beam energy of 180 MeV. Transitions within the Sm nuclei were enhanced by using the Microball charged particle array and gamma-ray de-excitation was studied using Gammasphere. A new highly deformed band has been observed in the data and assigned to Sm-136. Comparison of the properties of the new band with Woods-Saxon cranking calculations suggests that it is built upon a nu(i(13/2))(2) configuration,The band shows evidence for an interaction at h omega similar to 0.7 MeV. This has tentatively been interpreted as resulting from a crossing between the alpha = + 1/2 signatures of the [532]5/2 and [541]1/2 proton orbitals. The previously known nu i(13/2) intruder band in Sm-135 was also observed and extended to higher rotational frequency. Both structures show good agreement with extended total Routhian surface calculations. [S0556-2813(98)01212-6]. C1 Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Royal Inst Technol, Dept Phys 1, S-10444 Stockholm, Sweden. RP O'Brien, NJ (reprint author), Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. NR 27 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3212 EP 3218 DI 10.1103/PhysRevC.58.3212 PG 7 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200022 ER PT J AU Joss, DT Paul, ES Clark, RM Lee, IY Asztalos, SJ Becker, JA Bernstein, L Cederwall, B Deleplanque, MA Diamond, RM Fallon, P Farris, LP Hauschild, K Hibbert, IM Kelly, WH Macchiavelli, AO Nolan, PJ O'Brien, NJ Semple, AT Stephens, FS Wadsworth, R AF Joss, DT Paul, ES Clark, RM Lee, IY Asztalos, SJ Becker, JA Bernstein, L Cederwall, B Deleplanque, MA Diamond, RM Fallon, P Farris, LP Hauschild, K Hibbert, IM Kelly, WH Macchiavelli, AO Nolan, PJ O'Brien, NJ Semple, AT Stephens, FS Wadsworth, R TI Lifetime measurements of a triaxial band in Ce-133 SO PHYSICAL REVIEW C LA English DT Article ID MASS REGION; SUPERDEFORMED BANDS; NUCLEI; SHAPE AB Lifetimes of states within a triaxial band belonging to;the gamma-soft nucleus Ce-133 have been determined through a Doppler-broadened line shape analysis. A value, Q(t)approximate to 2.2 eb, has been found for the transition quadrupole moment which is considerably smaller than that of superdeformed structures (Q(t)approximate to 7.4 e b) in this mass region. The results are discussed in terms of deformation self-consistent calculations based on the total Routhian surface formalism. [S0556-2813(98)01912-8]. C1 Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Iowa State Univ, Ames, IA 50011 USA. RP Joss, DT (reprint author), Univ Liverpool, Oliver Lodge Lab, POB 147, Liverpool L69 7ZE, Merseyside, England. RI Hauschild, Karl/A-6726-2009; Cederwall, Bo/M-3337-2014 OI Cederwall, Bo/0000-0003-1771-2656 NR 20 TC 8 Z9 8 U1 1 U2 1 PU AMER 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 DEC PY 1998 VL 58 IS 6 BP 3219 EP 3222 DI 10.1103/PhysRevC.58.3219 PG 4 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200023 ER PT J AU Kaye, RA Riley, LA Solomon, GZ Tabor, SL Semmes, P AF Kaye, RA Riley, LA Solomon, GZ Tabor, SL Semmes, P TI Collective behavior in Rb-78 SO PHYSICAL REVIEW C LA English DT Article ID Y-82; ODD; DEFORMATION; SIGNATURE; BANDS AB Mean lifetimes of 10 states in Rb-78 have been measured using the recoil-distance method. The gamma-ray spectra of the recoils produced following the Ni-58(Na-23,2pn) Rb-78 reaction at 70 MeV were observed in prompt coincidence using the FSU plunger in the Pitt-FSU detector array. Different decry curves in different coincidence gates provide additional confirmation for the 153 keV doublet in the level scheme. The alternating pattern of B(M1) strengths observed previously in the yrast band was seen to continue down to lower spins but with an attenuated magnitude, in agreement with neighboring odd-odd nuclei Br-74 and Y-82 A slight reduction in collectivity with decreasing spin was inferred in the lowest positive- and negative-parity bands based on the gradual decrease in the B(E2) strengths. Particle-rotor model calculations predict strong alternations in both the signature splitting and B(MI) strength pattern in the positive-parity yrast band, in qualitative agreement with the experimental results. [S0556-2813(98)02812-X]. C1 Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Tennessee Technol Univ, Dept Phys, Cookeville, TN 38505 USA. RP Kaye, RA (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. OI Riley, Lewis/0000-0001-5921-7296 NR 16 TC 8 Z9 8 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3228 EP 3236 DI 10.1103/PhysRevC.58.3228 PG 9 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200025 ER PT J AU Ghugre, SS Kharraja, B Garg, U Janssens, RVF Carpenter, MP Crowell, B Khoo, TL Lauritsen, T Nisius, D Mueller, W Reviol, W Riedinger, LL Kaczarowski, R AF Ghugre, SS Kharraja, B Garg, U Janssens, RVF Carpenter, MP Crowell, B Khoo, TL Lauritsen, T Nisius, D Mueller, W Reviol, W Riedinger, LL Kaczarowski, R TI High-spin states in Rh-97,Rh-98 SO PHYSICAL REVIEW C LA English DT Article ID COINCIDENCE AB High-spin states in Rh-97,Rh-98 (Z=45) were populated via the Cu-65(S-36,xn)Rh-97,Rh-98 (x=4,3) fusion-evaporation reactions. More than 40 additional transitions have been identified and placed in the decay schemes of these nuclei. The level scheme of Rh-97 has been extended up to tentative spins of J(pi) = 39/2(+),37/2(-), and the placement of some of the previously known transitions has been revised. The level structure of Rh-97 indicates a single-particle nature and the observed levels are reproduced well by spherical shell-model calculations. The level scheme of Rh-98 has been extended up to spins J similar to 20 (h) over bar and up to an excitation energy of similar to 10 MeV. The low-spin structure of Rh-98(J less than or equal to 10 (h) over bar), appears to indicate also a single particle structure, as supported by the stretched coupling scheme [Rh-97(J')x nu(d(5/2))= Rh-98(J)]. [S0556-2813(98)03912-0]. C1 Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Soltan Inst Nucl Studies, PL-05400 Swierk, Poland. RP Ghugre, SS (reprint author), IUCDAEF Calcutta Ctr, Sector III-LB-8, Calcutta 700091, W Bengal, India. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 21 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3243 EP 3251 DI 10.1103/PhysRevC.58.3243 PG 9 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200027 ER PT J AU Hwang, JK Ramayya, AV Gilat, J Hamilton, JH Peker, LK Rasmussen, JO Kormicki, J Ginter, TN Babu, BRS Beyer, CJ Jones, EF Donangelo, R Zhu, SJ Griffin, HC Ter Akopian, GM Oganessian, YT Daniel, AV Ma, WC Varmette, PG Cole, JD Aryaeinejad, R Drigert, MW Stoyer, MA AF Hwang, JK Ramayya, AV Gilat, J Hamilton, JH Peker, LK Rasmussen, JO Kormicki, J Ginter, TN Babu, BRS Beyer, CJ Jones, EF Donangelo, R Zhu, SJ Griffin, HC Ter Akopian, GM Oganessian, YT Daniel, AV Ma, WC Varmette, PG Cole, JD Aryaeinejad, R Drigert, MW Stoyer, MA TI Rotational bands in Nb101-103 and Y-98,Y-100 nuclei and identification of yrast bands in La-146 and Pr-149 SO PHYSICAL REVIEW C LA English DT Article ID OCTUPOLE CORRELATIONS; NEUTRON-RICH AB Several gamma transitions in Nb101-103, Y-98,Y-100, La-146, and Pr-149 are identified from spontaneous fission studies employing a Cf-252 source and the Gammasphere detector array. In particular, the pairing-free bands in Y-100 and Nb-102 are extended, two rather highly deformed negative-parity hands feeding the 4.3-s beta-decaying isomer of Nb-102 are identified, and their possible bandhead configurations are discussed. In the case of Nb-101,Nb-103, We have extended previously reported level schemes by over 20 transitions in each nuclide. For the fission partners La-146 and Pr-149 we have elucidated their previously unreported yrast level schemes. [S0556-2813(98)04112-0]. C1 Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Fed Rio de Janeiro, Inst Fis, BR-21945970 Rio De Janeiro, Brazil. Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China. Univ Michigan, Ann Arbor, MI 48104 USA. Joint Inst Nucl Res, Dubna 141980, Russia. Joint Inst Heavy Ion Res, Oak Ridge, TN 37835 USA. Mississippi State Univ, Dept Phys, Mississippi State, MS 39762 USA. Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. ORISE, UNISOR, Oak Ridge, TN 37831 USA. RP Hwang, JK (reprint author), Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. NR 14 TC 39 Z9 41 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3252 EP 3259 DI 10.1103/PhysRevC.58.3252 PG 8 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200028 ER PT J AU Talou, P Carjan, N Strottman, D AF Talou, P Carjan, N Strottman, D TI Time-dependent properties of proton decay from crossing single-particle metastable states in deformed nuclei SO PHYSICAL REVIEW C LA English DT Article AB A dynamical study of the decay of a metastable state by quantum tunneling through an anisotropic, nonseparable, two-dimensional potential barrier is performed by the numerical solution of the time-dependent Schrodinger equation. Initial quasistationary proton states are chosen in the framework of a deformed Woods-Saxon single-particle model. The decay of two sets of states corresponding to true and quasi-level-crossing is studied and the evolution of their decay properties as a function of nuclear deformation is calculated around the crossing point;Tbe results show that the investigation of the proton decay from metastable states in deformed nuclei can unambiguously distinguish between the two types of crossing and determine the structure: of the nuclear states involved. [S0556-2813(98)00912-1]. C1 CEN Bordeaux Gradignan, F-33175 Gradignan, France. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Talou, P (reprint author), CEN Bordeaux Gradignan, F-33175 Gradignan, France. NR 19 TC 18 Z9 20 U1 2 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 DEC PY 1998 VL 58 IS 6 BP 3280 EP 3285 DI 10.1103/PhysRevC.58.3280 PG 6 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200031 ER PT J AU Myers, WD Swiatecki, WJ AF Myers, WD Swiatecki, WJ TI Nuclear diffuseness as a degree of freedom SO PHYSICAL REVIEW C LA English DT Article AB The response of the nuclear energy to changes in neutron and proton surface diffusenesses is investigated using the Thomas-Fermi model. Algebraic expressions are provided for the energy cost of changing the two diffusenesses away from their equilibrium values. This will make it possible to generalize the macroscopic-microscopic calculations of nuclear masses and deformation energies by the inclusion of the neutron and proton diffusenesses as degrees of freedom (to be varied along with the shape degrees of freedom). One result, which is suggested by the relatively low cost in macroscopic energy of increasing the diffuseness of a heavy nucleus by 10% (abour 4 MeV), is that superheavy nuclei near Z=126, N=184 may have a fair chance of becoming stabilized by shell effects. An appendix introduces an improved measure of surface diffuseness, with certain advantages over the conventional Sussmann width b. [S0556-2813(98)03612-7]. C1 Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Myers, WD (reprint author), Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. NR 11 TC 21 Z9 22 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 DEC PY 1998 VL 58 IS 6 BP 3368 EP 3373 DI 10.1103/PhysRevC.58.3368 PG 6 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200041 ER PT J AU Lane, MR Gregorich, KE Lee, DM Wierczinski, B McGrath, CA Hendricks, MB Shaughnessy, DA Strellis, DA Sylwester, ER Wilk, PA Hoffman, DC AF Lane, MR Gregorich, KE Lee, DM Wierczinski, B McGrath, CA Hendricks, MB Shaughnessy, DA Strellis, DA Sylwester, ER Wilk, PA Hoffman, DC TI Production cross sections of (261)(105)Ha from the Cf-250(N-15,4n) and Am-243(Ne-22,4n) reactions SO PHYSICAL REVIEW C LA English DT Article ID CHEMISTRY AB We have measured the production cross section of 1.8-s (261)Ha from two different reactions. It was produced in the Cf-250(N-15,4n) reaction at 84 MeV and in the Am-243(Ne-22,4n) reaction at 116 MeV. Our rotating wheel system with a special parent-daughter stepping mode was used to detect alpha-alpha correlations between (261)Ha and Lr-257. We measured 13 and 9 correlations in the two reactions, respectively. Assuming a 100% alpha branch, we have determined the production cross section of (261)Ha to be 0.51+/-0.20 nb in the Cf-250(N-15,4n) reaction at 84 MeV, and 0.25+/-0.11 nb in the Am-243(Ne-22,4n) reaction at 116 MeV. Based on the number of fission events observed in the latter reaction, we have been able to set an upper limit of 18% for the spontaneous fission branch of (261)Ha. [S0556-2813(98)02211-0]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Chalmers Univ Technol, Dept Nucl Chem, Gothenburg, Sweden. RP Lane, MR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, MS 70A-3307, Berkeley, CA 94720 USA. RI Wilk, Philip/B-5954-2008; McGrath, Christopher/E-8995-2013 NR 15 TC 8 Z9 10 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3413 EP 3418 DI 10.1103/PhysRevC.58.3413 PG 6 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200046 ER PT J AU Heilbronn, L Madey, R Elaasar, M Htun, M Frankel, K Gong, WG Anderson, BD Baldwin, AR Jiang, J Keane, D McMahan, MA Rathbun, WH Scott, A Shao, Y Watson, JW Westfall, GD Yennello, S Zhang, WM AF Heilbronn, L Madey, R Elaasar, M Htun, M Frankel, K Gong, WG Anderson, BD Baldwin, AR Jiang, J Keane, D McMahan, MA Rathbun, WH Scott, A Shao, Y Watson, JW Westfall, GD Yennello, S Zhang, WM TI Neutron yields from 435 MeV/nucleon Nb stopping in Nb and 272 MeV/nucleon Nb stopping in Nb and Al SO PHYSICAL REVIEW C LA English DT Article ID CROSS-SECTIONS; MEV-NUCLEON; COLLISIONS; CARBON AB Neutron fluences were measured from 435 MeV/nucleon Nb ions stopping in a Nb target and 272 MeV/ nucleon Nb ions stopping in targets of Nb and Al for neutrons above 20 MeV and at laboratory angles between 3 degrees and 80 degrees. The resultant spectra were integrated over angles to produce neutron energy distributions and over energy to produce neutron angular distributions. The total neutron yields for each system were obtained by integrating over the angular distributions. The angular distributions from all three systems are peaked forward, and the energy distributions from all three systems show an appreciable yield of neutrons with velocities greater than the beam velocity. Comparison of the total neutron yields from the two Nb+Nb systems suggests that the average neutron multiplicity decreases with decreasing projectile energy. Comparison of the total yields from the two 272 MeV/nucleon systems suggests that the total yields show the same dependence on projectile and target mass number as do total inclusive neutron cross sections. The data are compared with Boltzmann-Uehling-Uhlenbeck model calculations. [S0556-2813(98)05312-6]. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Kent State Univ, Kent, OH 44242 USA. MPI, D-80805 Munich, Germany. Michigan State Univ, E Lansing, MI 48824 USA. RP Heilbronn, L (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Heilbronn, Lawrence/J-6998-2013; Yennello, Sherry/B-5803-2015 OI Heilbronn, Lawrence/0000-0002-8226-1057; Yennello, Sherry/0000-0003-3963-5217 NR 27 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3451 EP 3461 DI 10.1103/PhysRevC.58.3451 PG 11 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200051 PM 11725795 ER PT J AU Chen, CM Johnson, MB Ernst, DJ AF Chen, CM Johnson, MB Ernst, DJ TI Forward elastic amplitudes of high-energy pions and kaons on nuclei SO PHYSICAL REVIEW C LA English DT Article ID TOTAL CROSS-SECTIONS; DELTA-RESONANCE; CHARGE-EXCHANGE; SCATTERING; MODEL; DYNAMICS; CARBON; MEV/C; C-12 AB Experimental elastic angular distributions for pions and kaons in the region of laboratory momentum from 600 to 900 MeV/c over the nuclear-Coulomb interference region are analyzed to extract both the real and imaginary part of the forward meson-nucleus scattering amplitude. For pions, results for the total cross sections extracted are smaller than those found from transmission experiments. The real part of the amplitude is found to have an interesting energy dependence. The significance of this result for the behavior of hadrons in nuclei is discussed. For kaons, only qualitative results were obtained due to limited data. [S0556-2813(98)01112-1]. C1 St Johns & St Marys Inst Technol, Tam Sui 25135, Taipei Cty, Taiwan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. RP Chen, CM (reprint author), St Johns & St Marys Inst Technol, Tam Sui 25135, Taipei Cty, Taiwan. NR 38 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 DEC PY 1998 VL 58 IS 6 BP 3500 EP 3507 DI 10.1103/PhysRevC.58.3500 PG 8 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200057 ER PT J AU Ahle, L Akiba, Y Ashktorab, K Baker, MD Beavis, D Britt, HC Chang, J Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Crawford, HJ Cumming, JB Debbe, R Dunlop, JC Eldredge, W Engelage, J Fung, SY Garcia, E Gushue, S Hamagaki, H Hansen, LF Hayano, RS Heintzelman, G Judd, E Kang, J Kim, EJ Kumagai, A Kurita, K Lee, JH Luke, J Miake, Y Mignerey, A Moskowitz, B Moulson, M Muentz, C Nagamiya, S Namboodiri, MN Ogilvie, CA Olness, J Remsberg, LP Sako, H Sangster, TC Seto, R Shea, J Shigaki, K Soltz, R Steadman, SG Stephens, GSF Tannenbaum, MJ Thomas, JH Ueno-Hayashi, S Videbaek, F Wang, F Wu, Y Xiang, H Xu, GH Yagi, K Yao, H Zajc, WA Zhu, F AF Ahle, L Akiba, Y Ashktorab, K Baker, MD Beavis, D Britt, HC Chang, J Chasman, C Chen, Z Chi, CY Chu, YY Cianciolo, V Cole, BA Crawford, HJ Cumming, JB Debbe, R Dunlop, JC Eldredge, W Engelage, J Fung, SY Garcia, E Gushue, S Hamagaki, H Hansen, LF Hayano, RS Heintzelman, G Judd, E Kang, J Kim, EJ Kumagai, A Kurita, K Lee, JH Luke, J Miake, Y Mignerey, A Moskowitz, B Moulson, M Muentz, C Nagamiya, S Namboodiri, MN Ogilvie, CA Olness, J Remsberg, LP Sako, H Sangster, TC Seto, R Shea, J Shigaki, K Soltz, R Steadman, SG Stephens, GSF Tannenbaum, MJ Thomas, JH Ueno-Hayashi, S Videbaek, F Wang, F Wu, Y Xiang, H Xu, GH Yagi, K Yao, H Zajc, WA Zhu, F TI Kaon production in Au+Au collisions at 11.6A GeV/c SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; NUCLEUS-NUCLEUS COLLISIONS; 14.6A GEV/C; DISTRIBUTIONS; ENERGIES; MATTER AB A systematic study of the spectra and yields of K(+) and K(-) is reported by experiment E866 as a function of centrality in Au+Au collisions at 11.6A GeV/c. The invariant transverse spectra for both kaon species are well described by exponentials in m(t), with inverse slope parameters that are largest at midrapidity and which increase with centrality. The inverse slopes of the K(+) spectra are slightly larger than the inverse slopes of the K(-) spectra. The kaon rapidity density peaks at midrapidity with the K(+) distribution wider in rapidity than K-. The integrated total yields of K(+) and K(-) increase nonlinearly and steadily with the number of projectile participants. The yield per participant for kaons is two to three times larger than the yield from N-N collisions. This enhancement suggests that the majority of kaons in central Au+Au reactions are produced in secondary hadronic collisions. There is no evidence for an onset of additional kaon production from a possible small volume of baryon-rich quark-gluon plasma. The differences between K(+) and K(-) rapidity distributions and transverse spectra are consistent with a lower phase space for K(-) production due to a higher energy threshold. These differences also exclude simple thermal models that assume emission from a common equilibrated system. [S0556-2813(98)01011-5]. C1 MIT, Cambridge, MA 02139 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Riverside, Riverside, CA 92507 USA. High Energy Accel Res Org, KEK, Tsukuba, Ibaraki 305, Japan. High Energy Accel Res Org, KEK, Tanashi Branch, Tanashi, Tokyo 188, Japan. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Yonsei Univ, Seoul 120749, South Korea. Univ Maryland, College Pk, MD 20742 USA. Univ Tokyo, Sch Sci, Ctr Nucl Study, Tanashi, Tokyo 188, Japan. Columbia Univ, New York, NY 10027 USA. Nevis Labs, Irvington, NY 10533 USA. RP Ahle, L (reprint author), Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Mignerey, Alice/D-6623-2011; seto, richard/G-8467-2011; Cumming, James/I-3358-2013; Hayano, Ryugo/F-7889-2012; HAMAGAKI, HIDEKI/G-4899-2014; OI Ogilvie, Craig/0000-0002-5188-5123; Cumming, James/0000-0001-6930-0958; Hayano, Ryugo/0000-0002-1214-7806; Tannenbaum, Michael/0000-0002-8840-5314; Thomas, James/0000-0002-6256-4536 NR 28 TC 91 Z9 91 U1 0 U2 0 PU AMER 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 DEC PY 1998 VL 58 IS 6 BP 3523 EP 3538 DI 10.1103/PhysRevC.58.3523 PG 16 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200060 ER PT J AU Kahana, DE Kahana, SH AF Kahana, DE Kahana, SH TI Two phase simulation of ultrarelativistic nuclear collisions SO PHYSICAL REVIEW C LA English DT Article ID GEV-C; PARTICLE; ENERGY; FRAGMENTATION; DYNAMICS; CASCADE; QUARK; MODEL; PP AB A two phase cascade is presented for ultrahigh energy ion-ion collisions from root s = 17-200 GeV. First a high-energy cascade is performed, in which original baryons and any freed hard partons collide. This stage ignores energy loss from soft processes. In this first version no hard processes, aside from Drell-Yan production, are included. The space-time history of the hard cascade is used to reconstruct the soft energy loss. Soft meson production is heated as coherent over groups of interacting nucleons. Two body data, though, are used to guide this reconstruction. A second, low-energy cascade is then carried out. The model selected to describe elementary hadron-hadron collisions in the soft cascade incorporates generic mesons and baryons as the agents for rescattering. We imagine a constituent quark model applies, with generic mesons consisting of an excited pair, and generic baryons constructed from three quarks. The chief result is a reconciliation of the important Drell-Yan measurements, indicating high-mass lepton pairs are produced as if no energy is lost from the nucleons, with the apparent success of a purely hadronic, soft cascade in describing nucleon stopping and meson production in heavy ion experiments at the CERN SPS. The LUCIFER II code may be downloaded under the GNU General Public License from http://bnlnth.phy.bnl.gov/. [S0556-2813(98)02011-1]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. SUNY Stony Brook, Dept Phys, Stony Brook, NY 11791 USA. RP Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. OI Kahana, David Ewan/0000-0003-1266-9089; Kahana, Sidney/0000-0002-5790-9384 NR 55 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 2469-9985 EI 2469-9993 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3574 EP 3586 DI 10.1103/PhysRevC.58.3574 PG 13 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200065 ER PT J AU Mekjian, AZ Schlei, BR Strottman, D AF Mekjian, AZ Schlei, BR Strottman, D TI Various models for pion probability distributions from heavy-ion collisions SO PHYSICAL REVIEW C LA English DT Article ID BOSE-EINSTEIN CORRELATIONS; HIGH-ENERGY COLLISIONS; MULTIPLICITY DISTRIBUTIONS; RELATIVISTIC HYDRODYNAMICS; FRAGMENTATION; INTERFEROMETRY; FLUCTUATIONS; BEHAVIOR AB Various models for pion multiplicity distributions produced in relativistic heavy ion collisions are discussed. The models include a relativistic hydrodynamic model, a thermodynamic description, an emitting source pion laser model, and a description which generates a negative binomial description. The approach developed can be used to discuss other cases which will be mentioned. The pion probability distributions for these various cases are compared. Comparison of the pion laser model and Bose-Einstein condensation in a laser trap and with the thermal model are made. The thermal model and hydrodynamic model are also used to illustrate why the number of pions never diverges and why the Bose-Einstein correction effects are relatively small. The pion emission strength eta of a Poisson emitter and a critical density eta(c) are connected in a thermal model by eta/n(c) = e(-m/T)<1, and this fact reduces any Bose-Einstein correction effects in the number and number fluctuation of pions. Fluctuations can be much larger than Poisson in the pion laser model and for a negative binomial description. The dan representation of the negative binomial distribution due to Van Hove and Giovannini is discussed using the present description. Applications to CERN/NA44 and CERN/NA49 data are discussed in terms of the relativistic hydrodynamic model. [S0556-2813(98)04912-7]. C1 Rutgers State Univ, Dept Phys, Piscataway, NJ 08854 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, DDT DO, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Mekjian, AZ (reprint author), Rutgers State Univ, Dept Phys, Piscataway, NJ 08854 USA. EM mekjian@ruthep.rutgers.edu; schlei@LANL.gov; dds@LANL.gov NR 50 TC 15 Z9 15 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 DEC PY 1998 VL 58 IS 6 BP 3627 EP 3635 DI 10.1103/PhysRevC.58.3627 PG 9 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200069 ER PT J AU Maris, P Roberts, CD AF Maris, P Roberts, CD TI Pseudovector components of the pion, pi(0)->gamma gamma, and F-pi(q(2)) SO PHYSICAL REVIEW C LA English DT Article ID DYSON-SCHWINGER EQUATIONS; FORM-FACTOR; ELECTROPRODUCTION; CONFINEMENT; PROPAGATOR; BREAKING; PHYSICS; GEV2; QCD AB As a consequence of dynamical chiral symmetry breaking the pion Bethe-Salpeter amplitude necessarily contains terms proportional to gamma(5)gamma.P and gamma(5)gamma.k, where k is the relative and P the total momentum of the constituents. These terms are essential for the preservation of low-energy theorems, such as the Gell-Mann-Oakes-Renner relation and those describing anomalous decays of the pion, and to obtaining an electromagnetic pion form factor that falls as 1/q(2) for large q(2), up to calculable In q(2) corrections. In a simple model, which correlates low- and high-energy pion observables, we find q(2)F(pi)(q(2))similar to 0.12-0.19 GeV2 for q(2)greater than or similar to 10 GeV2. [S0556-2813(98)02512-6]. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Maris, P (reprint author), Argonne Natl Lab, Div Phys, Bldg 203, Argonne, IL 60439 USA. NR 22 TC 104 Z9 104 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 DEC PY 1998 VL 58 IS 6 BP 3659 EP 3665 DI 10.1103/PhysRevC.58.3659 PG 7 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200073 ER PT J AU Warren, GA Alarcon, R Armstrong, C Asavapibhop, B Barkhuff, DH Bertozzi, W Burkert, V Chen, J Chen, JP Comfort, JR Dale, D Dodson, G Dolfini, S Dow, K Epstein, M Farkhondeh, M Finn, JM Gilad, S Gothe, RW Jiang, X Jones, M Joo, K Karabarbounis, A Kelly, J Kowalski, S Kunz, C Liu, D Lourie, RW Madey, R Margaziotis, D Markowitz, P McIntyre, JI Mertz, C Milbrath, BD Miskimen, R Mitchell, J Mukhopadhyay, S Papanicolas, CN Perdrisat, C Punjabi, V Qin, L Rutt, P Sarty, A Shaw, J Soong, SB Tieger, D Tschalaer, C Turchinetz, W Ulmer, P Van Verst, S Vellidis, C Weinstein, LB Williamson, S Woo, RJ Young, A AF Warren, GA Alarcon, R Armstrong, C Asavapibhop, B Barkhuff, DH Bertozzi, W Burkert, V Chen, J Chen, JP Comfort, JR Dale, D Dodson, G Dolfini, S Dow, K Epstein, M Farkhondeh, M Finn, JM Gilad, S Gothe, RW Jiang, X Jones, M Joo, K Karabarbounis, A Kelly, J Kowalski, S Kunz, C Liu, D Lourie, RW Madey, R Margaziotis, D Markowitz, P McIntyre, JI Mertz, C Milbrath, BD Miskimen, R Mitchell, J Mukhopadhyay, S Papanicolas, CN Perdrisat, C Punjabi, V Qin, L Rutt, P Sarty, A Shaw, J Soong, SB Tieger, D Tschalaer, C Turchinetz, W Ulmer, P Van Verst, S Vellidis, C Weinstein, LB Williamson, S Woo, RJ Young, A TI Induced proton polarization for pi(0) electroproduction at Q(2)=0.126 GeV2/c(2) around the Delta(1232) resonance SO PHYSICAL REVIEW C LA English DT Article ID ANALYZING POWER; SCATTERING; MODEL AB We present a measurement of the induced proton polarization P-n in pi(0) electroproduction on the proton around the Delta resonance. The measurement was made at a central invariant mass and a squared four-momentum transfer of W=1231 MeV and Q(2)=0.126 GeV2/c(2), respectively. We measured a large induced polarization, P-n = -0.397 +/- 0.055 +/- 0.009. The data suggest that the scalar background is larger than expected from a recent effective Hamiltonian model. [S0556-2813(98)02012-3]. C1 Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. Univ Bonn, Dept Phys, D-5300 Bonn, Germany. Calif State Univ Los Angeles, Dept Phys & Astron, Los Angeles, CA 90032 USA. Coll William & Mary, Dept Phys, Williamsburg, VA 23187 USA. Florida State Univ, Dept Phys, Tallahassee, FL 32306 USA. Kent State Univ, Dept Phys, Kent, OH 44242 USA. MIT, Dept Phys, Nucl Sci Lab, Cambridge, MA 02139 USA. MIT, Bates Accelerator Ctr, Cambridge, MA 02139 USA. Norfolk State Univ, Dept Phys & Engn, Norfolk, VA 23504 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. Rutgers State Univ, Dept Phys, Piscataway, NJ 08855 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Univ Athens, Inst Accelerating Syst & Applicat, Athens, Greece. Univ Athens, Dept Phys, Athens, Greece. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. Univ Maryland, Dept Phys & Astron, College Pk, MD 20742 USA. Univ Massachusetts, Dept Phys, Amherst, MA 01003 USA. Univ Virginia, Inst Nucl & Particle Phys, Charlottesville, VA 22901 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. RP Warren, GA (reprint author), Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. RI Sarty, Adam/G-2948-2014; McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 19 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3722 EP 3725 DI 10.1103/PhysRevC.58.3722 PG 4 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200081 ER PT J AU Garrett, PE Burke, DG Deleze, M Drissi, S Jolie, J Kern, J Lehmann, H Mannanal, SJ Warr, N AF Garrett, PE Burke, DG Deleze, M Drissi, S Jolie, J Kern, J Lehmann, H Mannanal, SJ Warr, N TI States in Os-191 observed with the Os-192(p,pn gamma) reaction SO PHYSICAL REVIEW C LA English DT Article ID HIGH-SPIN; EXCITATIONS AB States in Os-191 have been observed with the Os-192(p,pn gamma) reaction. The most intense gamma ray observed is the decay from the head of a previously assigned oblate decoupled band. Gamma rays in coincidence with this transition reveal a band structure up to spin 19/2(+). These results, together with those from a previous single-nucleon transfer study, are better reproduced in calculations assuming epsilon=0.17 and gamma=24 degrees, rather than epsilon=0.37 and gamma=43 degrees as previously suggested. Candidates for members of the ground state band are also suggested. [S0556-2813(98)02712-5]. C1 Univ Kentucky, Dept Phys & Astron, Lexington, KY 40506 USA. McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1, Canada. Univ Fribourg, Inst Phys, CH-1700 Fribourg, Switzerland. RP Garrett, PE (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-414,POB 808, Livermore, CA 94550 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP 3734 EP 3737 DI 10.1103/PhysRevC.58.3734 PG 4 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200084 ER PT J AU Macchiavelli, AO Clark, RM Deleplanque, MA Diamond, RM Fallon, P Lee, IY Stephens, FS Vetter, K AF Macchiavelli, AO Clark, RM Deleplanque, MA Diamond, RM Fallon, P Lee, IY Stephens, FS Vetter, K TI Rotational-like properties of the shears bands SO PHYSICAL REVIEW C LA English DT Article AB We present a model study of the quasirotational properties of a system consisting of two angular momentum vectors (blades) interacting via an effective force of the form V2P2(theta), where theta is the angle between the blades. We find the relationship between angular momentum and rotational frequency and derive from it the kinematical and dynamical moments of inertia. The dynamics of this simple system seems to account for the salient features of the shears bands. [S0556-2813(98)04811-0]. C1 Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Macchiavelli, AO (reprint author), Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. NR 9 TC 17 Z9 17 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 DEC PY 1998 VL 58 IS 6 BP 3746 EP 3748 DI 10.1103/PhysRevC.58.3746 PG 3 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200087 ER PT J AU Jalilian-Marian, J Koch, V AF Jalilian-Marian, J Koch, V TI Bremsstrahlung dileptons in ultrarelativistic heavy ion collisions SO PHYSICAL REVIEW C LA English DT Article AB We consider production of dilepton pairs through coherent. electromagnetic radiation during nuclear collisions. We show that the number of pairs produced through bremsstrahlung is about two orders of magnitude smaller than the yield measured by the CERES Collaboration. Therefore, coherent bremsstrahlung can be ruled out as an explanation for the observed enhancement of low mass dileptons in CERES and HELIOS data. [S0556-2813(98)04012-6]. C1 Lawrence Berkeley Lab, Div Nucl Sci, Nucl Theory Grp, Berkeley, CA 94720 USA. RP Jalilian-Marian, J (reprint author), Lawrence Berkeley Lab, Div Nucl Sci, Nucl Theory Grp, Berkeley, CA 94720 USA. NR 15 TC 1 Z9 1 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 DEC PY 1998 VL 58 IS 6 BP 3763 EP 3766 DI 10.1103/PhysRevC.58.3763 PG 4 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200092 ER PT J AU Paul, SD Baktash, C Satula, W Gross, CJ Birriel, I Clark, RM Cunningham, RA Devlin, M Fallon, P Galindo-Uribarri, A Ginter, T Lafosse, DR Kay, J Lerma, F Lee, IY Leyland, C Macchiavelli, AO MacDonald, BD Metcalfe, SJ Piechaczek, A Radford, DC Reviol, W Riedinger, LL Rudolph, D Rykaczewski, K Sarantites, DG Saladin, JX Shapira, D Sylvan, GN Tabor, SL Toth, KS Weintraub, W Winchell, DF Wood, VQ Wyss, R Yu, CH AF Paul, SD Baktash, C Satula, W Gross, CJ Birriel, I Clark, RM Cunningham, RA Devlin, M Fallon, P Galindo-Uribarri, A Ginter, T Lafosse, DR Kay, J Lerma, F Lee, IY Leyland, C Macchiavelli, AO MacDonald, BD Metcalfe, SJ Piechaczek, A Radford, DC Reviol, W Riedinger, LL Rudolph, D Rykaczewski, K Sarantites, DG Saladin, JX Shapira, D Sylvan, GN Tabor, SL Toth, KS Weintraub, W Winchell, DF Wood, VQ Wyss, R Yu, CH TI Band structure in Y-79 and the question of T=O pairing SO PHYSICAL REVIEW C LA English DT Article ID SHAPE TRANSITION; IDENTICAL BANDS; EXCITED-STATES; NUCLEI; ISOTOPES; REGION; SR-78 AB Gamma rays in the N=Z + 1 nucleus Y-79 were identified using the reaction Si-28(Fe-54, p2n)Y-79 at a 200 MeV beam energy and an experimental setup consisting of an array of Ge detectors and the Recoil Mass Spectrometer at Oak Ridge National Laboratory. With the help of additional gamma-gamma coincidence data obtained with Gammasphere, these gamma rays were found to form a strongly coupled rotational band with rigid-rotor-like behavior. Results of conventional Nilsson-Strutinsky cranked shell model calculations, which predict a deformation of beta(2)similar to 0.4, are in excellent agreement with the properties of this band. Similar calculations for the neighboring N=Z and N=Z + 1 nuclei are also in good agreement with experimental data. This suggests that the presence of the putative T=0 neutron-proton pairing does not significantly affect such simple observables as the moments of inertia of these bands at low spins. [S0556-2813(98)50612-7]. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Univ Pittsburgh, Dept Phys, Pittsburgh, PA 15260 USA. Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. SERC, Daresbury Lab, CCLRC, Warrington WA4 4AD, Cheshire, England. Washington Univ, Dept Chem, St Louis, MO 63130 USA. Vanderbilt Univ, Dept Phys & Astron, Nashville, TN 37235 USA. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Louisiana State Univ, Dept Phys, Baton Rouge, LA 70803 USA. Florida State Univ, Tallahassee, FL 32306 USA. Royal Inst Technol, Phys Dept Frescati, S-10405 Stockholm, Sweden. RP Paul, SD (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Rudolph, Dirk/D-4259-2009; Devlin, Matthew/B-5089-2013; radford, David/A-3928-2015 OI Rudolph, Dirk/0000-0003-1199-3055; Devlin, Matthew/0000-0002-6948-2154; NR 20 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD DEC PY 1998 VL 58 IS 6 BP R3037 EP R3041 DI 10.1103/PhysRevC.58.R3037 PG 5 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200002 ER PT J AU Yu, CH Batchelder, JC Bingham, CR Grzywacz, R Rykaczewski, K Toth, KS Akovali, Y Baktash, C Galindo-Uribarri, A Ginter, TN Gross, CJ Karny, M Kim, SH MacDonald, BD Paul, SD Radford, DC Szerypo, J Weintraub, W AF Yu, CH Batchelder, JC Bingham, CR Grzywacz, R Rykaczewski, K Toth, KS Akovali, Y Baktash, C Galindo-Uribarri, A Ginter, TN Gross, CJ Karny, M Kim, SH MacDonald, BD Paul, SD Radford, DC Szerypo, J Weintraub, W TI In-beam spectroscopy study of the proton emitter (151)Lu SO PHYSICAL REVIEW C LA English DT Article ID RADIOACTIVITY; NUCLEI AB Gamma rays decaying from the excited states of the proton-unbound (151)Lu were observed for the first time in an experiment using the (96)Ru((58)Ni, p2n)(151)Lu reaction. These gamma rays were identified by correlating prompt gamma radiations at the target position with (151)Lu proton radioactivities at the focal plane of a recoil mass separator. Systematic data on N = 80 isotones suggest a possible isomeric level at high spin in (151)Lu. Our measurement was unable to observe such an isomer, but provided an upper limit on its half-life. The observed gamma rays in (151)Lu can be interpreted in terms of two possible level structures. [S0556-2813(98)50812-6]. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Vanderbilt Univ, Dept Phys, Nashville, TN 37235 USA. Warsaw Univ, Inst Phys Expt, Warsaw, Poland. Georgia Inst Technol, Sch Phys, Atlanta, GA 30332 USA. Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RP Yu, CH (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI radford, David/A-3928-2015 NR 19 TC 16 Z9 20 U1 0 U2 1 PU AMER 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 DEC PY 1998 VL 58 IS 6 BP R3042 EP R3045 DI 10.1103/PhysRevC.58.R3042 PG 4 WC Physics, Nuclear SC Physics GA 149BL UT WOS:000077585200003 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, 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, HL Cihangir, S Clark, AG Cobal, R 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, H Freeman, J Friedman, J 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 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 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, 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, HL Cihangir, S Clark, AG Cobal, R 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, H Freeman, J Friedman, J 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 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 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 Collaborat TI Observation of B-c mesons in p(p)over-bar collisions at root s=1.8 TeV SO PHYSICAL REVIEW D LA English DT Article ID SILICON VERTEX DETECTOR; FRAGMENTATION FUNCTIONS; PARTON DISTRIBUTIONS; SEMILEPTONIC DECAYS; HADRONIC COLLISIONS; E+E ANNIHILATION; SEARCH; QUARKS; CHARM AB We report the observation of bottom-charmed mesons B-c in 1.8 TeV collisions using the CDF detector at the Fermilab Tevatron. The B-c mesons were found through their semileptonic decays, B-c(+/-) --> J/psi l(+/-)X. A fit to the J/psi l mass distribution yielded 20.4(-5.5)(+6.2) events from B-c mesons. A test of the null hypothesis, i.e., an attempt to fit the data with background alone, was rejected at the level of 4.8 standard deviations. By studying the quality of the fit as a function of the assumed B-c mass, we determined M(B-c) = 6.40 +/- 0.39 (stat.)+/-0.13 (syst) GeV/c(2). From the distribution of trilepton intersection points in the plane transverse to the beam direction we measured the B-c lifetime to be tau(B-c) = 0.46(-0.16)(+0.18) (stat)+/-0.03 (syst) ps. We also measured the ratio of production cross section times branching fraction for Bc+ --> J/psi l(+) nu relative to that for B+ --> J/psi K+ to be sigma(B-c) X B(B-c --> J/psi l nu)/sigma(B) X B(B-->J/psi K) = 0.132(-0.037)(+0.041) (stat)+/-0.031 (syst)(-0.020)(+0.032)(lifetime). [S0556-2821(98)01421-0]. C1 Kek Nat Lab High Energy Phys, Tsukuba 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. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. CERN, 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 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, Trieste, Italy. Univ Udine, Ist Nazl Fis Nucl, I-33100 Udine, Italy. Univ Tsukuba, Tsukuba 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 Kek Nat Lab High Energy Phys, Tsukuba 305, Japan. RI vilar, rocio/D-7454-2014; 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; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580 NR 35 TC 191 Z9 195 U1 2 U2 5 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 DEC 1 PY 1998 VL 58 IS 11 AR 112004 DI 10.1103/PhysRevD.58.112004 PG 29 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800011 ER PT J AU Abe, K Akagi, T Anthony, PL Antonov, R Arnold, RG Averett, T Band, HR Bauer, JM Borel, H Bosted, PE Breton, V Button-Shafer, J Chen, JP Chupp, TE Clendenin, J Comptour, C Coulter, KP Court, G Crabb, D Daoudi, M Day, D Dietrich, FS Dunne, J Dutz, H Erbacher, R Fellbaum, J Feltham, A Fonvieille, H Frlez, E Garvey, D Gearhart, R Gomez, J Grenier, P Griffioen, KA Hoibraten, S Hughes, EW Hyde-Wright, C Johnson, JR Kawall, D Klein, A Kuhn, SE Kuriki, M Lindgren, R Liu, TJ Lombard-Nelsen, RM Marroncle, J Maruyama, T Maruyama, XK McCarthy, J Meyer, W Meziani, ZE Minehart, R Mitchell, J Morgenstern, J Petratos, GG Pitthan, R Pocanic, D Prescott, C Prepost, R Raines, P Raue, B Reyna, D Rijllart, A Roblin, Y Rochester, LS Rock, SE Rondon, OA Sick, I Smith, LC Smith, TB Spengos, M Staley, F Steiner, P St Lorant, S Stuart, LM Suekane, F Szalata, ZM Tang, H Terrien, Y Usher, T Walz, D Wesselmann, F White, JL Witte, K Young, CC Youngman, B Yuta, H Zapalac, G Zihlmann, B Zimmermann, D AF Abe, K Akagi, T Anthony, PL Antonov, R Arnold, RG Averett, T Band, HR Bauer, JM Borel, H Bosted, PE Breton, V Button-Shafer, J Chen, JP Chupp, TE Clendenin, J Comptour, C Coulter, KP Court, G Crabb, D Daoudi, M Day, D Dietrich, FS Dunne, J Dutz, H Erbacher, R Fellbaum, J Feltham, A Fonvieille, H Frlez, E Garvey, D Gearhart, R Gomez, J Grenier, P Griffioen, KA Hoibraten, S Hughes, EW Hyde-Wright, C Johnson, JR Kawall, D Klein, A Kuhn, SE Kuriki, M Lindgren, R Liu, TJ Lombard-Nelsen, RM Marroncle, J Maruyama, T Maruyama, XK McCarthy, J Meyer, W Meziani, ZE Minehart, R Mitchell, J Morgenstern, J Petratos, GG Pitthan, R Pocanic, D Prescott, C Prepost, R Raines, P Raue, B Reyna, D Rijllart, A Roblin, Y Rochester, LS Rock, SE Rondon, OA Sick, I Smith, LC Smith, TB Spengos, M Staley, F Steiner, P St Lorant, S Stuart, LM Suekane, F Szalata, ZM Tang, H Terrien, Y Usher, T Walz, D Wesselmann, F White, JL Witte, K Young, CC Youngman, B Yuta, H Zapalac, G Zihlmann, B Zimmermann, D TI Measurements of the proton and deuteron spin structure functions g(1) and g(2) SO PHYSICAL REVIEW D LA English DT Review ID DEEP-INELASTIC-SCATTERING; BJORKEN SUM-RULE; POLARIZED STRUCTURE FUNCTIONS; HYPERON SEMILEPTONIC DECAYS; NUCLEON STRUCTURE FUNCTIONS; SMALL-X-BEHAVIOR; ENERGY ELECTRON-BEAMS; MAGNETIC FORM-FACTORS; RESONANCE REGION; PARTON-MODEL AB Measurements are reported of the proton and deuteron spin structure functions g(1)(p) and g(1)(d) at beam energies of 29.1, 16.2., and 9.7 GeV, and g(2)(p) and g(2)(d) at a beam energy of 29.1 GeV. The integrals Gamma(p) = integral(0)(1)g(1)(p)(x, Q(2))dx and Gamma(d) = integral(0)(1)g(1)(d)(x, Q(2))dx were evaluated at fixed Q(2) = 3 (GeV/c)(2) using the full data set to yield Gamma(p) = 0.132+/-0.003(stat)+/-0.009(syst) and Gamma(d)=0.047+/-0.003+/-0.006. The Q(2) dependence of the ratio g(1)/F-1 was studied and found to be small for Q(2) > 1 (GeV/c)(2). Within experimental precision the g(2) data are well described by the twist-2 contribution, g(2)(WW). Twist-3 matrix elements were extracted and compared to theoretical predictions. The asymmetry A(2) was measured and found to be significantly smaller than the positivity limit root R for both proton and deuteron targets. A(2)(p) is found to be positive and inconsistent with zero. Measurements of g(1) in the resonance region show strong variations with x and Q2, consistent with resonant amplitudes extracted from unpolarized data. These data allow us to study the Q(2) dependence of the integrals Gamma(p) and Gamma(n) below the scaling region. [S0556-2821(98)06919-7]. C1 Tohoku Univ, Sendai, Miyagi 980, Japan. American Univ, Washington, DC 20016 USA. Univ Basel, Inst Phys, CH-4056 Basel, Switzerland. Univ Blaise Pascal, CNRS, IN2P3, LPC, F-63170 Aubiere, France. Ctr Etud Saclay, Serv Phys Nucl, DAPNIA, F-91191 Gif Sur Yvette, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Massachusetts, Amherst, MA 01003 USA. Univ Michigan, Ann Arbor, MI 48109 USA. USN, Postgrad Sch, Monterey, CA 93943 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Univ Penn, Philadelphia, PA 19104 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Stanford Univ, Stanford, CA 94305 USA. Temple Univ, Philadelphia, PA 19122 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Univ Virginia, Charlottesville, VA 22901 USA. Coll William & Mary, Williamsburg, VA 23187 USA. Univ Wisconsin, Madison, WI 53706 USA. Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. Univ Bonn, D-53113 Bonn, Germany. FFIYM, N-2007 Kjeller, Norway. Kent State Univ, Kent, OH 44242 USA. Florida Int Univ, Miami, FL 33199 USA. CERN, CH-1211 Geneva 23, Switzerland. RP Abe, K (reprint author), Tohoku Univ, Sendai, Miyagi 980, Japan. RI Averett, Todd/A-2969-2011; Rondon Aramayo, Oscar/B-5880-2013; Frlez, Emil/B-6487-2013; Day, Donal/C-5020-2015 OI Day, Donal/0000-0001-7126-8934 NR 186 TC 192 Z9 192 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 DEC 1 PY 1998 VL 58 IS 11 AR 112003 PG 54 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800010 ER PT J AU Adeva, B Akdogan, T Arik, E Arvidson, A Badelek, B Bardin, G Baum, G Berglund, P Betev, L Bird, IG Birsa, R Bjorkholm, P de Botton, N Boutemeur, M Bradamante, F Bravar, A Bressan, A Bultmann, S Burtin, E Cavata, C Crabb, D Cranshaw, J Cuhadar, T Dalla Torre, S van Dantzig, R Derro, B Deshpande, A Dhawan, S Dulya, C Dyring, A Eichblatt, S Faivre, JC Fasching, D Feinstein, F Fernandez, C Forthmann, S Frois, B Gallas, A Garzon, JA Gilly, H Giorgi, M von Goeler, E Goertz, S Golutvin, IA Gracia, G de Groot, N Perdekamp, MG Haft, K von Harrach, D Hasegawa, T Hautle, P Hayashi, N Heusch, CA Horikawa, N Hughes, VW Igo, G Ishimoto, S Iwata, T Kabuss, EM Kageya, T Karev, A Kessler, HJ Ketel, TJ Kiryluk, J Kiryushin, I Kishi, A Kisselev, Y Klostermann, L Kramer, D Krivokhijine, V Kroger, W Kukhtin, V Kurek, K Kyynarainen, J Lamanna, M Landgraf, U Le Goff, JM Lehar, F de Lesquen, A Lichtenstadt, J Lindqvist, T Litmaath, N Lowe, M Magnon, A Mallot, GK Marie, F Martin, A Martino, J Matsuda, T Mayes, B McCarthy, JS Medved, K Meyer, W van Middelkoop, G Miller, D Miyachi, Y Mori, K Moromisato, J Nagaitsev, A Nassalski, J Naumann, L Niinikoski, TO Oberski, JEJ Ogawa, A Ozben, C Pereira, H Perrot-Kunne, F Peshekhonov, D Piegia, R Pinsky, L Platchkov, S Plo, M Pose, D Postma, H Pretz, J Puntaferro, R Pussieux, T Radel, G Rijllart, A Reicherz, G Roberts, J Rock, S Rodriguez, M Rondio, E Ropelewski, L Sabo, I Saborido, J Sandacz, A Savin, I Schiavon, P Schiller, A Schuler, KP Seitz, R Semertzidis, Y Sergeev, S Shanahan, P Sichtermann, EP Simeoni, F Smirnov, GI Staude, A Steinmetz, A Stiegler, U Stuhrmann, H Szleper, M Tessarotto, F Thers, D Tlaczala, W Tripet, A Unel, G Velasco, M Vogt, J Voss, R Whitten, C Windmolders, R Willumeit, R Wislicki, W Witzmann, A Ylostalo, J Zanetti, AM Zaremba, K Zamiatin, NI Zhao, J AF Adeva, B Akdogan, T Arik, E Arvidson, A Badelek, B Bardin, G Baum, G Berglund, P Betev, L Bird, IG Birsa, R Bjorkholm, P de Botton, N Boutemeur, M Bradamante, F Bravar, A Bressan, A Bultmann, S Burtin, E Cavata, C Crabb, D Cranshaw, J Cuhadar, T Dalla Torre, S van Dantzig, R Derro, B Deshpande, A Dhawan, S Dulya, C Dyring, A Eichblatt, S Faivre, JC Fasching, D Feinstein, F Fernandez, C Forthmann, S Frois, B Gallas, A Garzon, JA Gilly, H Giorgi, M von Goeler, E Goertz, S Golutvin, IA Gracia, G de Groot, N Perdekamp, MG Haft, K von Harrach, D Hasegawa, T Hautle, P Hayashi, N Heusch, CA Horikawa, N Hughes, VW Igo, G Ishimoto, S Iwata, T Kabuss, EM Kageya, T Karev, A Kessler, HJ Ketel, TJ Kiryluk, J Kiryushin, I Kishi, A Kisselev, Y Klostermann, L Kramer, D Krivokhijine, V Kroger, W Kukhtin, V Kurek, K Kyynarainen, J Lamanna, M Landgraf, U Le Goff, JM Lehar, F de Lesquen, A Lichtenstadt, J Lindqvist, T Litmaath, N Lowe, M Magnon, A Mallot, GK Marie, F Martin, A Martino, J Matsuda, T Mayes, B McCarthy, JS Medved, K Meyer, W van Middelkoop, G Miller, D Miyachi, Y Mori, K Moromisato, J Nagaitsev, A Nassalski, J Naumann, L Niinikoski, TO Oberski, JEJ Ogawa, A Ozben, C Pereira, H Perrot-Kunne, F Peshekhonov, D Piegia, R Pinsky, L Platchkov, S Plo, M Pose, D Postma, H Pretz, J Puntaferro, R Pussieux, T Radel, G Rijllart, A Reicherz, G Roberts, J Rock, S Rodriguez, M Rondio, E Ropelewski, L Sabo, I Saborido, J Sandacz, A Savin, I Schiavon, P Schiller, A Schuler, KP Seitz, R Semertzidis, Y Sergeev, S Shanahan, P Sichtermann, EP Simeoni, F Smirnov, GI Staude, A Steinmetz, A Stiegler, U Stuhrmann, H Szleper, M Tessarotto, F Thers, D Tlaczala, W Tripet, A Unel, G Velasco, M Vogt, J Voss, R Whitten, C Windmolders, R Willumeit, R Wislicki, W Witzmann, A Ylostalo, J Zanetti, AM Zaremba, K Zamiatin, NI Zhao, J TI Spin asymmetries A(1) and structure functions g(1) of the proton and the deuteron from polarized high energy muon scattering SO PHYSICAL REVIEW D LA English DT Article ID INELASTIC SCATTERING; GLOBAL ANALYSIS; CROSS-SECTIONS; NUCLEON; SEA; EXCHANGE AB We present the final results of the spin asymmetries A(1) and the spin structure functions g(1) of the proton and the deuteron in the kinematic range 0.0008 < x < 0.7 and 0.2 < Q(2) < 100 GeV2. For the determination of A(1), in addition to the usual method which employs inclusive scattering events and includes a large radiative background at low x, we use a new method which minimizes the radiative background by selecting events with at least one hadron as well as a muon in the final state. We find that this hadron method gives smaller errors for x < 0.02, so it is combined with the usual method to provide the optimal set of results. [S0556-2821(98)07017-9]. C1 Univ Santiago, Dept Particle Phys, Santiago De Compostela 15706, Spain. Univ Bielefeld, Dept Phys, D-33501 Bielefeld, Germany. Bogazici Univ, Istanbul, Turkey. Tech Univ Istanbul, Istanbul, Turkey. Ruhr Univ Bochum, Dept Phys, D-44780 Bochum, Germany. Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90024 USA. CERN, CH-1211 Geneva 23, Switzerland. Univ Freiburg, Dept Phys, D-79104 Freiburg, Germany. GKSS Forschungszentrum Geesthacht GmbH, D-21494 Geesthacht, Germany. Helsinki Univ Technol, Low Temp Lab, FIN-02150 Espoo, Finland. Helsinki Univ Technol, Inst Particle Phys Technol, FIN-02150 Espoo, Finland. Univ Houston, Dept Phys, Houston, TX 77204 USA. Joint Inst Nucl Res Dubna, RU-141980 Dubna, Russia. Univ Mainz, Inst Nucl Phys, D-55099 Mainz, Germany. Univ Mons, Fac Sci, B-7000 Mons, Belgium. Univ Munich, Dept Phys, D-80799 Munich, Germany. Nagoya Univ, CIRSE, Chikusa Ku, Nagoya, Aichi 466, Japan. Nagoya Univ, Dept Phys, Chikusa Ku, Nagoya, Aichi 466, Japan. Delft Univ Technol, FOM, NIKHEF, Delft, Netherlands. Free Univ Amsterdam, NL-1009 AJ Amsterdam, Netherlands. Northwestern Univ, Dept Phys, Evanston, IL 60208 USA. CEA Saclay, DAPNIA, F-91191 Gif Sur Yvette, France. Tel Aviv Univ, Sch Phys, IL-69978 Tel Aviv, Israel. Ist Nazl Fis Nucl, I-34127 Trieste, Italy. Univ Trieste, I-34127 Trieste, Italy. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. Univ Uppsala, Dept Radiat Sci, S-75121 Uppsala, Sweden. Soltan Inst Nucl Studies, PL-00681 Warsaw, Poland. Warsaw Univ, PL-00681 Warsaw, Poland. Yale Univ, Dept Phys, New Haven, CT 06511 USA. Northeastern Univ, Dept Phys, Boston, MA 02115 USA. Miyazaki Univ, Fac Engn, Miyazaki 88921, Japan. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. RIKEN, Inst Phys & Chem Res, Wako, Saitama 35101, Japan. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. Kek Nat Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. Rice Univ, Bonner Lab, Houston, TX 77251 USA. Univ Buenos Aires, Dept Phys, RA-1428 Buenos Aires, DF, Argentina. American Univ, Washington, DC 20016 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Warsaw Univ Technol, Warsaw, Poland. RP Adeva, B (reprint author), Univ Santiago, Dept Particle Phys, Santiago De Compostela 15706, Spain. RI Plo Casasus, Maximo/M-1445-2014; de Groot, Nicolo/A-2675-2009; Hautle, Patrick/C-1044-2012; Martin, Anna/I-9381-2012; Adeva, Bernardo /L-1378-2014; Saborido Silva, Juan Jose/K-1775-2014; CAVATA, Christian/P-6496-2015; Zhao, Jinkui/B-7872-2013; Le Goff, Jean-Marc/E-7629-2013; Semertzidis, Yannis K./N-1002-2013; Gallas Torreira, Abraham Antonio/K-6508-2014 OI Plo Casasus, Maximo/0000-0002-2289-918X; Hautle, Patrick/0000-0002-0502-8278; Martin, Anna/0000-0002-1333-0143; Adeva, Bernardo /0000-0001-9756-3712; Saborido Silva, Juan Jose/0000-0002-6270-130X; Zhao, Jinkui/0000-0002-7756-1952; Gallas Torreira, Abraham Antonio/0000-0002-2745-7954 NR 52 TC 309 Z9 309 U1 1 U2 10 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 DEC 1 PY 1998 VL 58 IS 11 AR 112001 DI 10.1103/PhysRevD.58.112001 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800008 ER PT J AU Arkani-Hamed, N Giudice, GF Luty, MA Rattazzi, R AF Arkani-Hamed, N Giudice, GF Luty, MA Rattazzi, R TI Supersymmetry-breaking loops from analytic continuation into superspace SO PHYSICAL REVIEW D LA English DT Article ID RENORMALIZATION-GROUP EQUATIONS; EFFECTIVE GAUGE-THEORIES; DIMENSIONAL REDUCTION; STANDARD MODEL; BETA-FUNCTION; REGULARIZATION AB We extend to all orders in perturbation theory a method to calculate supersymmetry-breaking effects by analytic continuation of the renormalization group into superspace. A central observation is that the renormalized gauge coupling can be extended to a real vector superfield, thereby including soft breaking effects in the gauge sector. We explain the relation between this vector superfield coupling and the "holomorphic" gauge coupling, which is a chiral superfield running only at one loop. We consider these issues for a number of regulators, including dimensional reduction. With this method, the renormalization group equations for soft-supersymmetry-breaking terms are directly related to supersymmetric beta functions and anomalous dimensions to all orders in perturbation theory. However, the real power of the formalism lies in computing finite soft breaking effects corresponding to high-loop component calculations. We prove that the gaugino mass in gauge-mediated supersymmetry breaking is "screened" from strong interactions in the messenger sector. We present a complete next-to-leading calculation of gaugino masses (two loops) and sfermion masses (three loops! in minimal gauge mediation and several other calculations of phenomenological relevance. [S0556-2821(98)06319-X]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Maryland, Dept Phys, College Pk, MD 20742 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 51 TC 175 Z9 175 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 DEC 1 PY 1998 VL 58 IS 11 AR 115005 DI 10.1103/PhysRevD.58.115005 PG 24 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800069 ER PT J AU Berger, EL Gordon, LE AF Berger, EL Gordon, LE TI Spin dependence of associated production of a prompt photon and a charm quark at next-to-leading order in QCD SO PHYSICAL REVIEW D LA English DT Article ID PARTON DISTRIBUTIONS; HADRON COLLIDERS; CROSS-SECTION; HERA-(N)OVER-RIGHT-ARROW; O(ALPHA-ALPHA(S)(2)); COLLISIONS; SCATTERING AB A second order, O(alpha(s)(2)), calculation in perturbative quantum chromodynamics is presented of the longitudinal spin dependence of the cross section for the two particle inclusive reaction p + p --> gamma + c + X for large values of the transverse momentum of the prompt photon and charm quark. Differential distributions are provided for the spin-averaged cross section and for the two-spin longitudinal polarization asymmetry A(LL) at the energy of the Brookhaven Relativistic Heavy Ion Collider. An assessment is given of the prospects for determination of the spin dependence of the charm quark density. [S0556-2821(98)06619-3]. C1 Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. Jefferson Lab, Newport News, VA 23606 USA. Hampton Univ, Hampton, VA 23668 USA. RP Berger, EL (reprint author), Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. NR 32 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 1998 VL 58 IS 11 AR 114024 DI 10.1103/PhysRevD.58.114024 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800045 ER PT J AU Brisudova, MM Burakovsky, L Goldman, T AF Brisudova, MM Burakovsky, L Goldman, T TI New glueball-meson mass relations SO PHYSICAL REVIEW D LA English DT Article ID PHENOMENOLOGY; DIFFRACTION; PHYSICS; POMERON; DECAYS; MODEL; RULE AB Using the "glueball dominance'' picture of the mixing between q (q) over bar mesons of different hidden flavors, we establish new glueball-meson mass relations which serve as a basis for glueball spectral systematics. For the tensor glueball mass 2.3+/-0.1 GeV used as an input parameter, these relations predict the following glueball masses: M(0(++))similar or equal to 1.65+/-0.05 GeV, M(1(--))similar or equal to 3.2+/-0.2 GeV, M(2(-+))similar or equal to 2.95+/-0.15 GeV, and M(3(--)) similar or equal to 2.8+/-0.15 GeV. We briefly discuss the failure of such relations for the pseudoscalar sector. Our results are consistent with (quasi)linear Regge trajectories for glueballs with a slope similar or equal to 0.3+/-0.1 GeV-2 [S0556-2821(98)10221-7]. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, MS B285, Los Alamos, NM 87545 USA. EM BRISUDA@T5.LANL.GOV; BURAKOV@T5.LANL.GOV; GOLDMAN@T5.LANL.GOV NR 45 TC 26 Z9 26 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 1998 VL 58 IS 11 AR 114015 DI 10.1103/PhysRevD.58.114015 PG 7 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800036 ER PT J AU Brodsky, SJ Gill, MS Melles, M Rathsman, J AF Brodsky, SJ Gill, MS Melles, M Rathsman, J TI Analytic extension of the modified minimal subtraction renormalization scheme SO PHYSICAL REVIEW D LA English DT Article ID QUANTUM CHROMODYNAMICS; GAUGE-THEORIES; PRECISION CORRECTIONS; COUPLING-CONSTANT; FLAVOR THRESHOLDS; BOUND-STATES; LATTICE QCD; Z-BOSON; ORDER; HEAVY AB The conventional definition of the running coupling alpha(<(MS)over bar>)(mu) in quantum chromodynamics is based on a solution to the renormalization group equations which treats quarks as either completely massless at a renormalization scale mu above their thresholds or infinitely massive at a scale below them. The coupling is thus nonanalytic at these thresholds. In this paper we present an analytic extension of alpha(<(MS)over bar>)(mu) which incorporates the finite-mass quark threshold effects into the running of the coupling. This is achieved by using a commensurate scale relation to connect alpha(<(MS)over bar>)(mu) to the physical alpha(v) scheme at specific scales, thus naturally including finite quark masses. The analytic extension inherits the exact analyticity of the alpha(v) scheme and matches the conventional <(MS)over bar> scheme far above and below mass thresholds. Furthermore just as in the alpha(v) scheme, there is no renormalization scale ambiguity, since the position of the physical mass thresholds is unambiguous. [S0556-2821(98)06321-8]. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 48 TC 37 Z9 37 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 DEC 1 PY 1998 VL 58 IS 11 AR 116006 DI 10.1103/PhysRevD.58.116006 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800083 ER PT J AU Dawson, S Dittmaier, S Spira, M AF Dawson, S Dittmaier, S Spira, M TI Neutral Higgs-boson pair production at hadron colliders: QCD corrections SO PHYSICAL REVIEW D LA English DT Article ID EUCLIDEAN ASYMPTOTIC EXPANSIONS; MINIMAL SUPERSYMMETRIC MODEL; LOW-ENERGY THEOREMS; RADIATIVE-CORRECTIONS; PROTON COLLIDERS; GREEN-FUNCTIONS; QUANTUM-FIELDS; MASS; PARTICLES; MSSM AB Neutral Higgs-boson-pair production provides the possibility of studying the trilinear Higgs couplings at future high-energy colliders. We present the QCD corrections to the gluon-initiated processes in the limit of a heavy top quark in the loops and the Drell-Yan-like pair production of scalar and pseudoscalar Higgs particles. The pp cross sections are discussed for CERN LHC energies within the standard model and its minimal supersymmetric extension. The QCD corrections are large, enhancing the total cross sections significantly. [S0556-2821(98)03719-9]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Hamburg, Inst Theoret Phys 2, D-22761 Hamburg, Germany. RP Dawson, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 58 TC 172 Z9 172 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 DEC 1 PY 1998 VL 58 IS 11 AR 115012 DI 10.1103/PhysRevD.58.115012 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800076 ER PT J AU Donnachie, A Page, PR AF Donnachie, A Page, PR TI Interpretation of experimental J(PC) exotic signals SO PHYSICAL REVIEW D LA English DT Article ID PARTIAL-WAVE ANALYSIS; FLUX-TUBE MODEL; HYBRID MESONS AB We investigate theoretical interpretations of the 1.4 GeV J(PC) exotic resonance reported by the E852 Collaboration. It is argued that interpretation in terms of a hybrid meson is untenable. A K-matrix analysis shows that the 1.4 GeV enhancement in the E852 eta pi;17i data can be understood as an interference of a non-resonant Deck-type background and a resonance at 1.6 GeV. A final state rescattering calculation shows that the 1.6 GeV hybrid has a eta pi width which is bounded above by 57 +/- 14 MeV. [S0556-2821(98)05321-1]. C1 Thomas Jefferson Natl Accelerator Facil, Theory Grp, Newport News, VA 23606 USA. RP Univ Manchester, Dept Phys & Astron, Manchester M13 9PL, Lancs, England. EM ad@a3.ph.man.ac.uk; prp@t5.lanl.gov RI Page, Philip/L-1885-2015 OI Page, Philip/0000-0002-2201-6703 NR 39 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 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 1998 VL 58 IS 11 AR 114012 DI 10.1103/PhysRevD.58.114012 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800033 ER PT J AU Hu, M Snow, GR Geer, S Marriner, J Martens, M Ray, RE Streets, J Wester, W Armstrong, T Buchanan, C Corbin, B Lindgren, M Muller, T Gustafson, R AF Hu, M Snow, GR Geer, S Marriner, J Martens, M Ray, RE Streets, J Wester, W Armstrong, T Buchanan, C Corbin, B Lindgren, M Muller, T Gustafson, R TI Search for muonic decays of the antiproton at the Fermilab Antiproton Accumulator SO PHYSICAL REVIEW D LA English DT Article AB A search for antiproton decay has been made at the Fermilab Antiproton Accumulator. Limits are placed on six antiproton decay modes which contain a final-state muon. At the 90% C.L. we find that tau((p) over bar)/B((p) over bar --> mu(-) gamma) >5.0 X 10(4) yr, tau((p) over bar)/B((p) over bar--> mu- pi(0)) > 4.8 x 10(4) yr, tau((p) over bar)/B((p) over bar-->mu- eta) >7.9 x 10(3) yr, tau((p) over bar)/B((p) over bar--> mu- gamma gamma) > 2.3 X 10(4) yr, tau((p) over bar)/B((p) over bar--> mu(-) pi(0)) > 4.3 X 10(3) yr, and tau((p) over bar)/B((p) over bar-->mu(-) K-L(0)) > 6.5 X 10(3) yr. [S0556-2821(98)50223-8]. C1 Univ Nebraska, Lincoln, NE 68588 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Penn State Univ, University Pk, PA 16802 USA. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Michigan, Ann Arbor, MI 48109 USA. RP Snow, GR (reprint author), Univ Nebraska, Lincoln, NE 68588 USA. EM gsnow@unlhep.unl.edu NR 9 TC 4 Z9 4 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 1998 VL 58 IS 11 AR 111101 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800001 ER PT J AU Huston, J Kuhlmann, S Lai, HL Olness, F Owens, JF Soper, DE Tung, WK AF Huston, J Kuhlmann, S Lai, HL Olness, F Owens, JF Soper, DE Tung, WK TI Study of the uncertainty of the gluon distribution SO PHYSICAL REVIEW D LA English DT Article ID PARTON DISTRIBUTIONS; PHYSICS AB The uncertainty in the calculation of many important new processes at the Fermilab Tevatron and CERN LHC is dominated by that concerning the gluon distribution function. We investigate the uncertainty in the gluon distribution of the proton by systematically varying the gluon parameters in the global QCD analysis of parton distributions. The results depend critically on the parton momentum fraction x and the QCD scale Q(2). The uncertainties are presented for integrated gluon-gluon and gluon-quark luminosities for both the Tevatron and LHC as a function of root tau = root x(1)x(2) = root (s) over cap/s, the most relevant quantity for new particle production. The uncertainties are reasonably small, except for large x. [S0556-2821(98)09421-1]. C1 Michigan State Univ, E Lansing, MI 48824 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Florida State Univ, Tallahassee, FL 32306 USA. Natl Tsing Hua Univ, Hsinchu 300, Taiwan. Univ Oregon, Eugene, OR 97403 USA. So Methodist Univ, Dallas, TX 75275 USA. RP Huston, J (reprint author), Michigan State Univ, E Lansing, MI 48824 USA. NR 10 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 DEC 1 PY 1998 VL 58 IS 11 AR 114034 DI 10.1103/PhysRevD.58.114034 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800055 ER PT J AU Martin, SP Wells, JD AF Martin, SP Wells, JD TI Chiral symmetry breaking and effective Lagrangians for softly broken supersymmetric QCD SO PHYSICAL REVIEW D LA English DT Article ID GAUGE-THEORIES; 4 DIMENSIONS; LATTICE; DYNAMICS; MASSES; LIMIT; CHROMODYNAMICS; GLUINOS; MODEL AB We study supersymmetric QCD with N-fS-GAMMA; SEARCH; B->X(S)TAU(+)TAU(-); MASS AB In the standard model and many of its extensions, it is well known that all of the observables associated with the rare decays b --> s gamma and b --> s l(+) l(-) can be expressed in terms of the three Wilson coefficients C-7L,C-9L,C-10L(mu similar to m(b)), together with several universal kinematic functions. In particular, it has been shown that the numerical values of these coefficients can be uniquely extracted by a three-parameter global fit to data obtainable at future B factories given sufficient integrated luminosity. In this paper we examine if such global fits are also sensitive to new operators beyond those which correspond to the above coefficients, i.e., whether it is possible that new operators can be of sufficient importance for the three-parameter fit to fail and for this to be experimentally observable. Using the left-right symmetric model as an example of a scenario with an extended operator basis, we demonstrate via Monte Carlo techniques that such a possibility can indeed be realized. In some sense this potential failure of the global fit approach can actually be one of its greatest successes in identifying the existence of new physics. [S0556-2821(98)09021-3]. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Rizzo, TG (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 65 TC 15 Z9 15 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD DEC 1 PY 1998 VL 58 IS 11 AR 114014 DI 10.1103/PhysRevD.58.114014 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800035 ER PT J AU Suzuki, M AF Suzuki, M TI Final-state interaction phases of the two-body B decay: The bounds from the updated data SO PHYSICAL REVIEW D LA English DT Article ID CP VIOLATION; ASYMMETRIES AB The updated experimental data an used to analyze the final-state interaction phases of the two-body decay amplitudes of the B mesons, B-->(D) over bar pi, (D) over bar rho, (D) over bar*pi, and (D) over bar* rho. Combining the upper bounds on the branching fractions of the color-suppressed neutral modes with those of the charged modes, we have set constraints on the relative phases between the amplitudes A(B-0-->X-Y+) and A(B+-->(XY+)-Y-0) when X = (D) over bar or (D) over bar* and Y = pi or rho. The numbers that we have obtained point to small final-state interactions. When these relative phases are expressed in those of the isospin amplitudes, the bounds become less tight, since the experimental errors accumulate. In the decay where many multibody channels are open, however, there is little advantage in breaking up the observed amplitudes into the isospin eigenchannels for analysis of the final-state interactions. [S0556-2821(98)50323-2]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Suzuki, M (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 23 TC 23 Z9 23 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 DEC 1 PY 1998 VL 58 IS 11 AR 111504 DI 10.1103/PhysRevD.58.111504 PG 3 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 145NB UT WOS:000077376800007 ER PT J AU Ferer, M Smith, DH AF Ferer, M Smith, DH TI Transition from continuous to discontinuous material failure in a simple model of an adhesive layer SO PHYSICAL REVIEW E LA English DT Article ID FRACTURE; BREAKDOWN; DYNAMICS; CRACKS AB A fine-scale, quasistatic model was used to study the removal of a disordered adhesive layer by a uniform force applied perpendicular to the layer. The model includes randomly chosen bonding forces of adhesion between imaginary "gridblocks" within the layer and a substrate, as well as cooperative forces of cohesion between adjacent gridblocks. For small cooperative forces, the amount of failure varies continuously with the applied force F. From infinitesimal failure at a minimum threshold value of the force, the fraction of the layer removed, f(m)(F), increases to encompass the total layer, as the applied force increases. This layer-removal function sharpens as the cooperative forces are increased; i.e., the slope of the layer-removal function, Delta f(m)/Delta F, increases, so that the amount of failure is more and more sensitive to changes in the applied force. Indeed, this slope diverges with an exponent gamma approximate to 0.85 when the cooperative forces are approximately 2.1 as large as the adhesive forces. At small values of the cooperative forces, the layer-removal initiates at many locations and spreads to nearby blocks. The perimeter enclosing the area removed is fractal with a dimension D-p approximate to 1.3. Increasing the cooperative forces causes the failure to initiate at fewer locations in the array, but to spread farther because of the larger cooperative forces. At the critical value of 2.1 for the ratio of cohesive to adhesive forces, the number density of these initiation sites goes to zero, and the ''correlation'' length (average range of the spread of failure) diverges with exponent v approximate to 0.5. The characteristic time required for failure also diverges at the same critical value of cohesive/adhesive ratio; with an exponent, Delta approximate to 0.9. Therefore, increasing the cooperative forces of cohesion effects a transition from the continuous response reminiscent of systems with depinning transitions to the discontinuous response characteristic of standard material fracture. Indeed, the divergent correlation length signals a transition to the long-range elastic forces that have enabled mean-field (fiber-bundle) models to be used in the study of standard material fracture. [S1063-651X(98)07012-3]. C1 W Virginia Univ, Dept Phys, Morgantown, WV 26506 USA. US DOE, Fed Energy Technol Ctr, Morgantown, WV 26507 USA. RP Ferer, M (reprint author), W Virginia Univ, Dept Phys, POB 6315, Morgantown, WV 26506 USA. NR 41 TC 5 Z9 5 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 1998 VL 58 IS 6 BP 7071 EP 7078 DI 10.1103/PhysRevE.58.7071 PN A PG 8 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 148PV UT WOS:000077541800030 ER PT J AU Maslov, S De los Rios, P Marsili, M Zhang, YC AF Maslov, S De los Rios, P Marsili, M Zhang, YC TI Critical exponents of the anisotropic Bak-Sneppen model SO PHYSICAL REVIEW E LA English DT Article ID PUNCTUATED EQUILIBRIUM; EVOLUTION AB We analyze the behavior of the spatially anisotropic Bak-Sneppen model. We demonstrate that a nontrivial relation between critical exponents tau and mu = d/D, recently derived for the isotropic Bak-Sneppen model, holds for its anisotropic version as well. For the one-dimensional anisotropic Bak-Sneppen model, we derive an exact equation for the distribution of avalanche spatial sizes, and extract the value gamma = 2 for one of the critical exponents of the model. Other critical exponents are then determined from previously known exponent relations. Our results are in excellent agreement with Monte Carlo simulations of the model as well as with direct numerical integration of the new equation. [S1063-651X(98)13512-2]. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Fribourg, Inst Phys Theor, CH-1700 Fribourg, Switzerland. SISSA, Sch Adv Int Studies, I-34014 Trieste, Italy. INFM Unit, I-34014 Trieste, Italy. RP Maslov, S (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RI De Los Rios, Paolo/B-2456-2010; EPFL, LBS/B-3567-2010; Maslov, Sergei/C-2397-2009 OI De Los Rios, Paolo/0000-0002-5394-5062; Maslov, Sergei/0000-0002-3701-492X NR 10 TC 13 Z9 13 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 DEC PY 1998 VL 58 IS 6 BP 7141 EP 7145 DI 10.1103/PhysRevE.58.7141 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 148PV UT WOS:000077541800040 ER PT J AU Castillo, VM Hoover, WG AF Castillo, VM Hoover, WG TI Entropy production and Lyapunov instability at the onset of turbulent convection SO PHYSICAL REVIEW E LA English DT Article ID THERMAL TURBULENCE; NUMERICAL EVIDENCE; 2 DIMENSIONS; ATTRACTORS AB Computer simulations of a compressible fluid, convecting heat in two dimensions, suggest that, within a range of Rayleigh numbers, two distinctly different, but stable, time-dependent flow morphologies are possible. The simpler of the flows has two characteristic frequencies: the rotation frequency of the convecting rolls, and the vertical oscillation frequency of the rolls. Observables, such as the heat flux, have a simple-periodic (harmonic) time dependence. The more complex flow has at least one additional characteristic frequency-the horizontal frequency of the cold, downward- and the warm, upward-flowing plumes. Observables of this latter flow have a broadband frequency distribution. The two flow morphologies, at the same Rayleigh number, have different rates of entropy production and different Lyapunov exponents. The simpler "harmonic" flow transports more heat (produces entropy at a greater rate), whereas the more complex "chaotic'' flow has a larger maximum Lyapunov exponent (corresponding to a larger rate of phase-space information loss). A linear combination of these two rates is invariant for the two flow morphologies over the entire range of Rayleigh numbers for which the flows coexist, suggesting a relation between the two rates near the onset of convective turbulence. [S1063-651X(98)04612-1]. C1 Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Castillo, VM (reprint author), Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. NR 18 TC 9 Z9 9 U1 1 U2 3 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 DEC PY 1998 VL 58 IS 6 BP 7350 EP 7354 DI 10.1103/PhysRevE.58.7350 PN A PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 148PV UT WOS:000077541800067 ER PT J AU Durbin, MK Richter, AG Yu, CJ Kmetko, J Bai, JM Dutta, P AF Durbin, MK Richter, AG Yu, CJ Kmetko, J Bai, JM Dutta, P TI Backbone orientational order in fatty acid monolayers at the air-water interface SO PHYSICAL REVIEW E LA English DT Article ID X-RAY-DIFFRACTION; LANGMUIR-MONOLAYERS; PHASE-DIAGRAM; ROTATOR PHASE; TRANSITIONS; SURFACE; ALKANES AB We report on the first observation of superlattice x-ray diffraction peaks (indicating herringbone ordering of the molecular cross sections) in a saturated fatty acid Langmuir monolayer. In the CS phase the "forbidden" (21) peak is observed with a resolution-limited width, implying that the herringbone order is long range. We also searched for this characteristic peak in the S, L-2, L-2', and L-2" phases. Although each phase displayed some higher-order peaks, only the lowest-temperature (L-2") phase showed the herringbone peak. These results do not preclude the existence of short-range herringbone order in the other phases; a Landau theory of lipid monolayers [V. M. Kaganer and E. B. Loginov, Phys. Rev. Lett. 71, 2599 (1993)] predicts the existence of local herringbone order in some tilted phases, manifesting itself in the distortion of the molecular lattice from hexagonal. We have studied this distortion as a function of temperature along low-pressure isobars. The distortion goes to zero as the temperature is increased, but we do not see a first-order transition. [S1063-651X(98)13412-8]. C1 Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37830 USA. RP Durbin, MK (reprint author), Northwestern Univ, Dept Phys & Astron, Evanston, IL 60208 USA. RI Bai, Jianming/O-5005-2015 NR 21 TC 32 Z9 32 U1 0 U2 8 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 DEC PY 1998 VL 58 IS 6 BP 7686 EP 7690 DI 10.1103/PhysRevE.58.7686 PN B PG 5 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 148PW UT WOS:000077541900027 ER PT J AU Gerstenberg, MC Pedersen, JS Smith, GS AF Gerstenberg, MC Pedersen, JS Smith, GS TI Surface induced ordering of micelles at the solid-liquid interface SO PHYSICAL REVIEW E LA English DT Article ID OXIDE) TRIBLOCK-COPOLYMER; AQUEOUS-SOLUTION; NEUTRON-SCATTERING; BLOCK-COPOLYMERS; PHASE-BEHAVIOR; ADSORPTION; SHEAR; MICROEMULSIONS; WATER AB The surface induced ordering of triblock copolymer micelles in aqueous solution was measured with neutron reflectivity far above the critical micelle concentration. The scattering length density profiles showed a clear indication of ordered layers of micelles perpendicular to a quartz surface. The structure and interactions of the micelles were modeled in detail. The convolution of the center distribution of the micelles, obtained from Monte Carlo simulations of hard spheres at a hard wall, and the projected density of the micelle showed excellent agreement with the experimental profiles. [S1063-651X(98)06712-9]. C1 Riso Natl Lab, Dept Condensed Matter Phys & Chem, DK-4000 Roskilde, Denmark. Univ Calif Los Alamos Natl Lab, Manual Lujan Jr Neutron Scattering Ctr MSH805, Los Alamos, NM 87545 USA. RP Gerstenberg, MC (reprint author), Princeton Univ, Princeton Mat Inst, Princeton, NJ 08540 USA. RI Pedersen, Jan/A-8346-2008 OI Pedersen, Jan/0000-0002-7768-0206 NR 25 TC 24 Z9 24 U1 0 U2 6 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 DEC PY 1998 VL 58 IS 6 BP 8028 EP 8031 DI 10.1103/PhysRevE.58.8028 PN B PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 148PW UT WOS:000077541900077 ER PT J AU Ferri, S Calisti, A Stamm, R Talin, B Lee, RW Klein, L AF Ferri, S Calisti, A Stamm, R Talin, B Lee, RW Klein, L TI Electronic broadening model for high-n Balmer line profiles SO PHYSICAL REVIEW E LA English DT Article ID PLASMA AB a method for line profile computations of Stark broadened high principal quantum number (PQN) Balmer series transitions is presented. Since quasistatic electron effects must be included in these cases, the traditional low density/low quantum number impact approximation for the electron broadening operator cannot describe the entire profile. For the high plasma densities and/or high principal quantum numbers (PQN>12) considered, an improved electron broadening contribution is proposed. Using a frequency dependent election broadening operator, the line profile of the H Balmer n=13 transition is calculated using this electron operator and compared with profiles obtained using very accurate numerical simulations. The good agreement suggests that the procedure is sufficiently accurate to provide a predictive capability. [S1063-651X(98)50312-1]. C1 Univ Aix Marseille 1, Ctr St Jerome, CNRS UMR 6633, Lab Phys Interact Ion & Mol, F-13397 Marseille 20, France. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Howard Univ, Dept Phys, Washington, DC 20059 USA. RP Ferri, S (reprint author), Univ Aix Marseille 1, Ctr St Jerome, CNRS UMR 6633, Lab Phys Interact Ion & Mol, Case 232, F-13397 Marseille 20, France. NR 15 TC 4 Z9 4 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD DEC PY 1998 VL 58 IS 6 BP R6943 EP R6946 DI 10.1103/PhysRevE.58.R6943 PN A PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA 148PV UT WOS:000077541800012 ER PT J AU Zoldi, SM Liu, J Bajaj, KMS Greenside, HS Ahlers, G AF Zoldi, SM Liu, J Bajaj, KMS Greenside, HS Ahlers, G TI Extensive scaling and nonuniformity of the Karhunen-Loeve decomposition for the spiral-defect chaos state SO PHYSICAL REVIEW E LA English DT Article ID RAYLEIGH-BENARD CONVECTION; TRANSITION AB By analyzing large-aspect-ratio spiral-defect chaos (SDC) convection images, we show that the Karhunen-Loeve decomposition (KLD) scales extensively for subsystem sizes larger than 4d (d is the fluid depth), which strongly suggests that SDC is extensively chaotic. From this extensive scaling, the intensive length xi(KLD) is computed and found to have a different dependence on the Rayleigh number than the two-point correlation length xi(2). Local computations of xi(KLD) reveal a spatial nonuniformity of SDC images that extends over radii 18d 0) > 99%. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Ctr Particle Astrophys, Berkeley, CA 94720 USA. RP Goldhaber, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Perlmutter, Saul/I-3505-2015 OI Perlmutter, Saul/0000-0002-4436-4661 NR 16 TC 15 Z9 15 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-1573 J9 PHYS REP JI Phys. Rep.-Rev. Sec. Phys. Lett. PD DEC PY 1998 VL 307 IS 1-4 BP 325 EP 331 DI 10.1016/S0370-1573(98)00091-X PG 7 WC Physics, Multidisciplinary SC Physics GA 155GE UT WOS:000077937700040 ER PT J AU Peck, SC Kende, H AF Peck, SC Kende, H TI Differential regulation of genes encoding 1-aminocyclopropane-carboxylate (ACC) synthase in etiolated pea seedlings: effects of indole-3-acetic acid, wounding, and ethylene SO PLANT MOLECULAR BIOLOGY LA English DT Article DE 1-aminocyclopropane-1-carboxylate (ACC) synthase; auxin; wounding; ethylene; Pisum sativum ID PISUM-SATIVUM-L; 1-AMINOCYCLOPROPANE-1-CARBOXYLATE SYNTHASE; MESSENGER-RNA; EXCISED SEGMENTS; KEY ENZYME; CV ALASKA; 2 GENES; BIOSYNTHESIS; TOMATO; SEQUENCE AB Treatment of 5- to 6-day-old etiolated pea (Pisum sativum L.) seedlings with indole-3-acetic acid (IAA) induced within 15 min an increase in the transcript levels of two genes encoding 1-aminocyclopropane-1-carboxylate (ACC) synthase, Ps-ACS1 and Ps-ACS2. Simultaneous treatment with ethylene inhibited this increase and also caused a decrease in ACC synthase enzyme activity as compared to that of seedlings treated with IAA alone. These results indicate that ethylene inhibits its own biosynthesis by decreasing ACC synthase transcript levels via a negative feedback loop. Wounding of pea stems had no effect on the expression of Ps-ACS1, but led within 10 min to an increase in the mRNA levels of Ps-ACS2. This increase was also inhibited by ethylene. The wound signal was transmitted over a distance of at least 4 cm through the stem with no delay in induction or response intensity. The rapid transmission of the wound response is consistent with the possibility that a hydraulic or electric signal is responsible for the spread of the wound response. C1 Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48823 USA. RP Kende, H (reprint author), Michigan State Univ, MSU DOE Plant Res Lab, E Lansing, MI 48823 USA. NR 25 TC 38 Z9 43 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-4412 J9 PLANT MOL BIOL JI Plant Mol.Biol. PD DEC PY 1998 VL 38 IS 6 BP 977 EP 982 DI 10.1023/A:1006033030081 PG 6 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA 152EB UT WOS:000077762100007 PM 9869404 ER PT J AU Bonivert, WDB Cushnie, G AF Bonivert, WDB Cushnie, G TI NMFRC receives high grades from recent EPA survey SO PLATING AND SURFACE FINISHING LA English DT Editorial Material C1 Sandia Natl Labs, Livermore, CA 94551 USA. CAI Engn, Oakton, VA 22124 USA. RP Bonivert, WDB (reprint author), Sandia Natl Labs, M-S 9404,Box 969, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ELECTROPLATERS SOC INC PI ORLANDO PA 12644 RESEARCH PKWY, ORLANDO, FL 32826-3298 USA SN 0360-3164 J9 PLAT SURF FINISH JI Plat. Surf. Finish. PD DEC PY 1998 VL 85 IS 12 BP 64 EP 65 PG 2 WC Metallurgy & Metallurgical Engineering; Materials Science, Coatings & Films SC Metallurgy & Metallurgical Engineering; Materials Science GA 149QW UT WOS:000077617700008 ER PT J AU Walsh, J AF Walsh, J TI Nuclear designs: Great Britain, France, and China in the global governance of nuclear arms SO POLITICAL SCIENCE QUARTERLY LA English DT Book Review C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Walsh, J (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 1 TC 0 Z9 0 U1 0 U2 2 PU ACAD POLITICAL SCIENCE PI NEW YORK PA 475 RIVERSIDE DRIVE, SUITE 1274, NEW YORK, NY 10115-1274 USA SN 0032-3195 J9 POLIT SCI QUART JI Polit. Sci. Q. PD WIN PY 1998 VL 112 IS 4 BP 700 EP 701 PG 2 WC Political Science SC Government & Law GA YV322 UT WOS:000071811600015 ER PT J AU Mio, C Prausnitz, J AF Mio, C Prausnitz, J TI Solvent activities in solutions of star and linear poly(ethylene oxide) and polystyrene SO POLYMER LA English DT Article DE vapour-liquid equilibrium; star polymer; gravimetric method ID POLYMERS; COATINGS; SYSTEMS; POINT AB Solvent activities were measured using a gravimetric method in the range 48-70 degrees C. The polymers were: 15-arm, 20-arm star and linear poly(ethylene oxide), and 8-arm star and linear polystyrene. The solvents were acetone, chloroform and cyclohexane. In the concentrated regime, to 0.5 solvent weight fraction, there is no significant effect of polymer structure on solvent activities. (C) 1998 Elsevier Science Ltd. All rights reserved. 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, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. NR 16 TC 6 Z9 6 U1 2 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0032-3861 J9 POLYMER JI Polymer PD DEC PY 1998 VL 39 IS 25 BP 6401 EP 6405 DI 10.1016/S0032-3861(97)10074-X PG 5 WC Polymer Science SC Polymer Science GA 119LE UT WOS:000075896900027 ER PT J AU Reedy, RC AF Reedy, RC TI Studies of modern and ancient solar energetic particles SO PROCEEDINGS OF THE INDIAN ACADEMY OF SCIENCES-EARTH AND PLANETARY SCIENCES LA English DT Article DE solar energetic particles; cosmogenic nuclides; lunar rocks ID PROTON FLUENCE MODEL; COSMIC-RAY RECORD; EVENTS; CYCLES; MATTER AB Modern solar energetic particles (SEPs) have been studied for about 50 years by satellites and ground-based observations. These measurements indicate much about the nature of SEPs but cover too short a period to quantify the probabilities of very large solar particle events. Many SEPs have high enough energies to make nuclides in material in which they interact. Radionuclides measured in lunar samples have been used to extend the record about SEPs back several million years. Some new measurements of modern SEPs during the last solar cycle and new results for nuclides made by SEPs in lunar samples are presented and their implications discussed. Both the modern and ancient records need to be improved, and methods to get a better understanding of solar energetic particles discussed. The fluxes of SEPs during the last million years show an increasing trend when averaged over shorter radionuclide half-lives. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Mail Stop D436, Los Alamos, NM 87545 USA. EM rreedy@lanl.gov OI Reedy, Robert/0000-0002-2189-1303 NR 33 TC 12 Z9 12 U1 0 U2 0 PU INDIAN ACAD SCIENCES PI BANGALORE PA C V RAMAN AVENUE, SADASHIVANAGAR, P B #8005, BANGALORE 560 080, INDIA SN 0253-4126 J9 P INDIAN AS-EARTH JI Proc. Indian Acad. Sci.-Earth Planet. Sci PD DEC PY 1998 VL 107 IS 4 BP 433 EP 440 PG 8 WC Geosciences, Multidisciplinary SC Geology GA 176ZF UT WOS:000079181800020 ER PT J AU Glimm, J Sharp, D AF Glimm, J Sharp, D TI Stochastic methods for the prediction of complex multiscale phenomena SO QUARTERLY OF APPLIED MATHEMATICS LA English DT Article; Proceedings Paper CT International Symposium on Current and Future Challenges in Aoolied Mathematics, to Mark the 50th Anniversary of the Division-of-Applied-Mathematics CY 1998 CL PROVIDENCE, RHODE ISLAND SP Brown Univ, Div Appl Math ID RICHTMYER-MESHKOV INSTABILITY; RAYLEIGH-TAYLOR INSTABILITY; GROUP FIXED-POINT; POROUS-MEDIA; ANOMALOUS DIFFUSION; MODEL; VALIDATION; IMAGES; FIELD; LAWS AB The purpose of this paper is to develop a general framework for the prediction of complex multiscale phenomena and to illustrate this framework through comparison to two examples of current interest to the authors. Prediction involves a two-step process of inverse prediction to describe the system, given observations of its behavior, and forward prediction, to specify system behavior, given its description. C1 SUNY Stony Brook, Stony Brook, NY 11794 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. RP Glimm, J (reprint author), SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 75 TC 11 Z9 11 U1 0 U2 0 PU AMER MATHEMATICAL SOC PI PROVIDENCE PA 201 CHARLES ST, PROVIDENCE, RI 02940-2213 USA SN 0033-569X J9 Q APPL MATH JI Q. Appl. Math. PD DEC PY 1998 VL 56 IS 4 BP 741 EP 765 PG 25 WC Mathematics, Applied SC Mathematics GA 163NP UT WOS:000078412100010 ER PT J AU Chadwick, MB AF Chadwick, MB TI Neutron, proton, and photonuclear cross-sections for radiation therapy and radiation protection SO RADIATION AND ENVIRONMENTAL BIOPHYSICS LA English DT Review ID KERMA FACTORS; PARTICLE PRODUCTION; CARBON; SPECTRA; BOMBARDMENT; HYDROGEN; ENERGIES; 30-MEV; NUCLEI; O-16 AB I review recent work at Los Alamos undertaken to evaluate neutron, proton, and photonuclear cross-sections up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. In radiation protection, these data can be used to determine shielding requirements in accelerator environments and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross-section and kerma coefficient data with measurements are given. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Chadwick, MB (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM mbchadwick@lanl.gov NR 39 TC 8 Z9 8 U1 1 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0301-634X J9 RADIAT ENVIRON BIOPH JI Radiat. Environ. Biophys. PD DEC PY 1998 VL 37 IS 4 BP 235 EP 242 DI 10.1007/s004110050124 PG 8 WC Biology; Biophysics; Environmental Sciences; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Environmental Sciences & Ecology; Radiology, Nuclear Medicine & Medical Imaging GA 162PZ UT WOS:000078357100003 PM 10052673 ER PT J AU Lobrich, M Cooper, PK Rydberg, B AF Lobrich, M Cooper, PK Rydberg, B TI Joining of correct and incorrect DNA ends at double-strand breaks produced by high-linear energy transfer radiation in human fibroblasts SO RADIATION RESEARCH LA English DT Article ID PREMATURE CHROMOSOME CONDENSATION; HUMAN INTERPHASE CHROMOSOMES; FIELD GEL-ELECTROPHORESIS; IRRADIATED L5178Y CELLS; ALPHA-PARTICLES; MAMMALIAN-CELLS; IONIZING-RADIATION; X-RAY; RESTRICTION ENZYMES; INITIAL DAMAGE AB DNA double-strand breaks (DSBs) were measured within a 3.2-Mbp NotI fragment on chromosome 21 of cells of a normal human fibroblast cell line. Correct rejoining of DSBs was followed by measuring reconstitution of the original-size NotI fragment, and this was compared to total rejoining as measured by a conventional pulsed-field gel electrophoresis technique (FAR assay). After 80 Gy of particle irradiations with LETs in the range of 7-150 keV/mu m, it was found that the repair kinetics was generally slower after irradiation with high-LET particles compared to X irradiation and that a larger proportion of the breaks remained unrepaired after 24 h. On the other hand, the misrejoining frequency as measured by the difference between correct and total rejoining after 24 h did not change with LET, but was approximately the same for all radiations at this dose, equal to 25-30% of the initial breaks. This result is discussed in relation to formation of chromosomal aberrations, deletion mutations and other biological end points. (C) 1998 by Radiation Research Society. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Rydberg, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 51 TC 49 Z9 50 U1 0 U2 1 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 DEC PY 1998 VL 150 IS 6 BP 619 EP 626 DI 10.2307/3579884 PG 8 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA 142CT UT WOS:000077182900003 PM 9840181 ER PT J AU Gaylor, DW Gold, LS AF Gaylor, DW Gold, LS TI Regulatory cancer risk assessment based an a quick estimate of a benchmark dose derived from the maximum tolerated dose SO REGULATORY TOXICOLOGY AND PHARMACOLOGY LA English DT Article ID CARCINOGENIC POTENCY; ACUTE TOXICITY; UNCERTAINTY; BIOASSAYS; SAFETY AB The proposed U.S. Environmental Protection Agency carcinogen risk assessment guidelines employ a benchmark dose as a point of departure (POD) for low-dose risk assessment. If information on the carcinogenic mode of action for a chemical supports a nonlinear dose-response curve below the POD, a margin-of-exposure ratio between the POD and anticipated human exposure would be considered. The POD would be divided by uncertainty (safety) factors to arrive at a reference dose that is likely to produce no, or at most negligible, cancer risk for humans. If nonlinearity below the POD is not supported by sufficient evidence, then linear extrapolation from the incidence at the POD to zero would be used for low-dose cancer risk estimation. The carcinogen guidelines suggest that the lower 95% confidence limit on the dose estimated to produce an excess of tumors in 10% of the animals (LTD10) be used for the POD. Due to the relatively narrow range of doses in 2-year rodent bioassays and the limited range of statistically significant tumor incidence rates, the estimate of the LTD10 obtained from 2-year bioassays is constrained to a relatively narrow range of values. Because of this constraint, a simple, quick, and relatively precise determination of the LTD10 can be obtained by the maximum tolerated dose (MTD) divided by 7. All that is needed is a 90-day study to establish the MTD. It is shown that the LTD10 determined by this relatively easy procedure is generally within a factor of 10 of the LTD10 that would be estimated using tumor incidence rates from 2-year bioassays. Estimates of cancer potency from replicated 2-year bioassays, and hence estimates of cancer risk, have been show to vary by a factor of 4 around a median value. Thus, there may be little gain in precision of cancer risk estimates derived from a a-year bioassay, compared to the estimate based on the MTD from a 90-day study. If the anticipated human exposure were estimated to be small relative to the MTD/7 = LTD10, there may be little value in conducting a chronic 2-year study in rodents because the estimate of cancer risk would be low regardless of the results of a 2-year bioassay. Linear extrapolation to a risk of less than 1 in 100,000 and use of an uncertainty factor, e.g., of 10,000, would give the same regulatory "safe dose." Linear extrapolation to a virtually safe dose associated with a cancer risk estimate of less than one in a million mould be 10 times lower than the reference dose based on the LTD10/10,000. C1 US FDA, Natl Ctr Toxicol Res, Jefferson, AR 72079 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Gaylor, DW (reprint author), US FDA, Natl Ctr Toxicol Res, Jefferson, AR 72079 USA. NR 15 TC 18 Z9 18 U1 0 U2 3 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0273-2300 J9 REGUL TOXICOL PHARM JI Regul. Toxicol. Pharmacol. PD DEC PY 1998 VL 28 IS 3 BP 222 EP 225 DI 10.1006/rtph.1998.1258 PG 4 WC Medicine, Legal; Pharmacology & Pharmacy; Toxicology SC Legal Medicine; Pharmacology & Pharmacy; Toxicology GA 171GA UT WOS:000078853500005 PM 10049793 ER PT J AU Park, YJ Hofmayer, CH Chokshi, NC AF Park, YJ Hofmayer, CH Chokshi, NC TI Survey of seismic fragilities used in PRA studies of nuclear power plants SO RELIABILITY ENGINEERING & SYSTEM SAFETY LA English DT Article DE PRA; seismic fragilities; nuclear power plants AB In recent years, seismic PRA studies have been performed on a large number of nuclear power plants in the USA. This paper presents a summary of a survey on fragility databases and the range of evaluated fragility values of various equipment categories based on past PRAs. The survey includes the use of experience data, the interpretations of available test data, and the quantification of uncertainties. The surveyed fragility databases are limited to data available in the public domain such as NUREG reports, conference proceedings and other publicly available reports. The extent of the availability of data as well as limitations are studied and tabulated for various equipment categories. The survey of the fragility values in past PRA studies includes not only the best estimate values, but also the dominant failure modes and the estimated uncertainty levels for each equipment category. The engineering judgments employed in estimating the uncertainty in the fragility values are also studied. This paper provides a perspective on the seismic fragility evaluation procedures for equipment in order to clearly identify the engineering analysis and judgment used in past seismic PRA studies. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Brookhaven Natl Lab, Dept Adv Technol, Upton, NY 11973 USA. US Nucl Regulatory Commiss, Washington, DC 20555 USA. RP Park, YJ (reprint author), Brookhaven Natl Lab, Dept Adv Technol, POB 5000, Upton, NY 11973 USA. NR 17 TC 12 Z9 17 U1 1 U2 5 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0951-8320 J9 RELIAB ENG SYST SAFE JI Reliab. Eng. Syst. Saf. PD DEC PY 1998 VL 62 IS 3 BP 185 EP 195 DI 10.1016/S0951-8320(98)00019-2 PG 11 WC Engineering, Industrial; Operations Research & Management Science SC Engineering; Operations Research & Management Science GA 126JG UT WOS:000076289700004 ER PT J AU Young, BKF Osterheld, AL Price, DF Shepherd, R Stewart, RE Faenov, AY Magunov, AI Pikuz, TA Skobelev, IY Flora, F Bollanti, S Di Lazzaro, P Letardi, T Grilli, A Palladino, L Reale, A Scafati, A Reale, L AF Young, BKF Osterheld, AL Price, DF Shepherd, R Stewart, RE Faenov, AY Magunov, AI Pikuz, TA Skobelev, IY Flora, F Bollanti, S Di Lazzaro, P Letardi, T Grilli, A Palladino, L Reale, A Scafati, A Reale, L TI High-resolution X-ray spectrometer based on spherically bent crystals for investigations of femtosecond laser plasmas SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SOLID-DENSITY PLASMAS; PUMPED TI-SAPPHIRE; EXCIMER-LASER; SPECTROSCOPY; SPECTRA; PULSES; SATELLITES; RADIATION; GENERATION; TARGETS AB Ultrashort-pulse, laser-produced plasmas have become very interesting laboratory sources to study spectroscopically due to their very high densities and temperatures, and the high laser-induced electromagnetic fields present. Typically, these plasmas are of very small volume and very low emissivity. Thus, studying these near point source plasmas requires advanced experimental techniques. We present a new spectrometer design called the focusing spectrometer with spatial resolution (FSSR-2D) based on a spherically bent crystal which provides simultaneous high spectral (lambda/Delta lambda approximate to 10(4)) and spatial resolution (approximate to 10 mu m) as well as high luminosity (high collection efficiency). We described in detail the FSSR-2D case in which a small, near point source plasma is investigated. An estimate for the spectral and spatial resolution for the spectrometer is outlined based on geometric considerations. Using the FSSR-2D instrument, experimental data measured from both a 100 fs and a nanosecond pulse laser-produced plasma are presented. (C) 1998 American Institute of Physics. [S0034-6748(98)00712-6]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. VNIIFTRI, Multicharged Ions Spectra Data Ctr, Mendeleevo 141570, Moscow Region, Russia. ENEA, Dipartimento Innovaz, Settore Fis Applicata, I-00044 Frascati, Italy. INFN Frascati, I-00044 Frascati, Italy. Univ Aquila, Dipartimento Fis, I-67010 Coppito, Italy. Univ Aquila, INGS, INFN GS, I-67010 Coppito, Italy. Inst Sup Sanita, I-00040 Rome, Italy. Ist Nazl Fis Nucl, Sez Sanita, I-00040 Rome, Italy. RP Young, BKF (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 43 TC 63 Z9 65 U1 1 U2 5 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 DEC PY 1998 VL 69 IS 12 BP 4049 EP 4053 DI 10.1063/1.1149249 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 144BP UT WOS:000077293600005 ER PT J AU Logory, LM Farley, DR Conder, AD Belli, EA Bell, PM Miller, PL AF Logory, LM Farley, DR Conder, AD Belli, EA Bell, PM Miller, PL TI Characterization of an X-ray framing camera utilizing a charge coupled device or film as recording media SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A compact charge coupled device (CCD) camera system has been designed and characterized for use in the six inch manipulator (SIM) at the Nova laser facility. The camera system has been designed to directly replace the 35 mm film packages currently used in SIM-based x-ray imaging diagnostics. The unit's electronic package has been constructed for small size and high thermal conductivity which reduces the overall camera size and improves its performance when operated within the vacuum environment of the Nova target chamber. Measurements of the x-ray imager's contrast transfer function (CTF) were made under a variety of operating conditions on a static x-ray Manson source using both the CCD and Kodak T-Max 3200 film as recording media. The CTF data were converted to an equivalent modulation transfer function (MTF). The MTF plots show that the microchannel plate has a uniform response within our measurement accuracy along its strips. In a direction normal to the strip, however, the MTF is reduced due to the slant angle of the pores in the MCP. The measurements show that the CCD camera has a lower MTF response than T-MAX film for all spatial frequencies and configurations measured. However, data obtained from the film exhibited reciprocity failure and border effects that are not observed in the CCD data. Measurements indicate that the signal-to-noise ratio for the CCD data is four to six times larger than that obtained with film and higher photon flux levels were recorded. The CCD-based diagnostic offers immediate access to the data, improved dynamic range, and reduced turnaround time, while eliminating the need for film development, digitization, equipment, and personnel. (C) 1998 American Institute of Physics. [S0034-6748(98)00912-5]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Logory, LM (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Miller, Paul/E-6880-2013 NR 8 TC 6 Z9 6 U1 0 U2 2 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 DEC PY 1998 VL 69 IS 12 BP 4054 EP 4060 DI 10.1063/1.1149250 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 144BP UT WOS:000077293600006 ER PT J AU Lexa, D AF Lexa, D TI Hermetic holder for X-ray powder diffraction of air-sensitive differential scanning calorimetry samples SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB The design and performance of a hermetic holder for the preservation of air-sensitive differential scanning calorimetry samples during powder x-ray diffraction are described. The holder was developed specifically for the Perkin-Elmer DSC-2C type samples to be analyzed in a Rigaku D/max-2400V diffractometer. It could, however, easily be modified for use with a variety of diffractometers and larger samples. This holder provides simplicity of operation superior to previous holders at a fraction of the cost of environmental chambers. (C) 1998 American Institute of Physics. [S0034-6748(98)02612-4]. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Lexa, D (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. EM lexa@cmt.anl.gov NR 11 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD DEC PY 1998 VL 69 IS 12 BP 4249 EP 4250 DI 10.1063/1.1149240 PG 2 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 144BP UT WOS:000077293600039 ER PT J AU de Leon, JM de Coss, R Rubio-Ponce, A Salkola, MI Bishop, AR AF de Leon, JM de Coss, R Rubio-Ponce, A Salkola, MI Bishop, AR TI Polaronic signatures in structural and optical probes in high T-c superconductors SO REVISTA MEXICANA DE FISICA LA English DT Article; Proceedings Paper CT 14th Latin American Symposium on Solid State Physics CY JAN 11-16, 1998 CL OAXACA, MEXICO DE electron-phonon interaction; polaron; anharmonic lattice modes; neutron scattering ID NEUTRON-SCATTERING; YBA2CU3O7 AB A many body electron-phonon model which includes strong electron-electron correlations and electron-phonon interactions is used as st paradigm for the dynamics of the cluster metal-axial oxygen-metal present in several high-T-c superconductors, showing the presence of polaron tunelling. Energy-resolved correlation functions, derived from the model probe length and time scales pertinent for polaron tunelling, reconciling apparently contradictory experimental results of neutron diffraction and X-ray absorption fine structure. The calculated isotopic shift of phonon modes, associated with the axial oxygen, shows discrepancies with lattice dynamics calculations assuming rigid potentials, in agreement with recent optical measurements. C1 Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Fis Aplicada, Unidad Merida, Merida 97310, Yucatan, Mexico. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Inst Politecn Nacl, Ctr Invest & Estudios Avanzados, Dept Fis Aplicada, Unidad Merida, Apartado Postal 73 Cordemex, Merida 97310, Yucatan, Mexico. RI Mustre de Leon, Jose/B-5630-2009; CinvesNano-Merida, CinvesNano-Merida/C-5672-2013 OI Mustre de Leon, Jose/0000-0002-0513-2323; NR 14 TC 2 Z9 2 U1 0 U2 1 PU SOC MEXICANA FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD DEC PY 1998 VL 44 SU 3 BP 122 EP 125 PG 4 WC Physics, Multidisciplinary SC Physics GA 150QF UT WOS:000077675900033 ER PT J AU Mills, GS Neuhauser, KS AF Mills, GS Neuhauser, KS TI Urban risks of truck transport of radioactive material SO RISK ANALYSIS LA English DT Article DE RADTRAN; transportation risk; routing; spent nuclear fuel AB Truck transport of radioactive material (RAM), e.g., spent nuclear fuel (SNF), normally maximizes use of Interstate highways, which are safer and more efficient for truck transport in general. In the estimation of transportation risks, population bordering a route is a direct factor in determining consequences and an indirect factor in determining exposure times, accident probabilities and severities, and other parameters. Proposals to transport RAM may draw intense resistance from "stakeholders" based on concern for population concentrations along urban segments but the length of a route segment is also a determinative factor in estimating the transport risks. To quantify the relative importance of these two factors, a potential route for transport of SNF (strict use of Interstate highways) was selected and compared with a modified version that bypassed urban areas. The results suggest that emphasis on Interstate highways minimizes total route and urban segment risks. C1 Sandia Natl Labs, Dept 6341, Albuquerque, NM 87185 USA. RP Mills, GS (reprint author), Sandia Natl Labs, Dept 6341, MS 0718, Albuquerque, NM 87185 USA. NR 9 TC 4 Z9 4 U1 0 U2 0 PU KLUWER ACADEMIC/PLENUM PUBL PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD DEC PY 1998 VL 18 IS 6 BP 781 EP 785 DI 10.1111/j.1539-6924.1998.tb01120.x PG 5 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA 162QA UT WOS:000078357200014 ER PT J AU Hacker, BC AF Hacker, BC TI Radium girls: Women and industrial health reform, 1910-1935 SO SOCIAL HISTORY OF MEDICINE 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 1 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0951-631X J9 SOC HIST MED JI Soc. Hist. Med. PD DEC PY 1998 VL 11 IS 3 BP 521 EP 522 PG 2 WC History; History & Philosophy Of Science SC History; History & Philosophy of Science GA 160FM UT WOS:000078219800027 ER PT J AU White, MD Oostrom, M AF White, MD Oostrom, M TI Modeling surfactant-enhanced nonaqueous-phase liquid remediation of porous media SO SOIL SCIENCE LA English DT Article DE surfactant flushing; SEAR; STOMP; multiphase flow; remediation ID SOIL COLUMNS; RESIDUAL TETRACHLOROETHYLENE; AQUIFER REMEDIATION; MULTIPHASE FLOW; SOLUBILIZATION; SIMULATOR; DODECANE AB A mathematical model is developed to investigate the main processes associated with surfactant-enhanced nonaqueous-phase liquid (NAPL) remediation of porous media. The model couples four nonlinear mass balance conservation equations (i.e., water, NAPL-phase organic, aqueous-phase organic, and aqueous-phase surfactant) that incorporate aqueous- and NAPL-phase migration and transport of aqueous-phase dissolved surfactant and organics. Rate-limited solubilization of the organic into the aqueous phase is represented by a linear driving force expression and is dependent on the surfactant-enhanced equilibrium concentration. Surfactant-enhanced mobilization of the NAPL phase is incorporated using surfactant concentration-dependent interfacial tension lowering, scaled relative permeability-saturation-capillary pressure relations, and trapping number-dependent effective residual saturations for the nonwetting liquid. Sorption of surfactant is assumed to conform to a Langmuir isotherm model, whereas organic sorption is modeled using a linear isotherm with a surfactant and soil-organic content-dependent retardation coefficient. The model is used to simulate experiments described by Pennell et al, (1996) in which the NAPL perchloroethylene was flushed from sand columns using different surfactant solutions. C1 Pacific NW Lab, Environm Technol Div, Richland, WA 99352 USA. RP Oostrom, M (reprint author), Pacific NW Lab, Environm Technol Div, POB 999,MS K9-33, Richland, WA 99352 USA. NR 28 TC 19 Z9 20 U1 1 U2 5 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0038-075X J9 SOIL SCI JI Soil Sci. PD DEC PY 1998 VL 163 IS 12 BP 931 EP 940 DI 10.1097/00010694-199812000-00003 PG 10 WC Soil Science SC Agriculture GA 153LH UT WOS:000077834200003 ER PT J AU Shul, RJ Ren, F Wolfgang, E AF Shul, RJ Ren, F Wolfgang, E TI Special issue - Power semiconductor devices and processes - Preface SO SOLID-STATE ELECTRONICS LA English DT Editorial Material C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. Siemens AG, Corp Res, Dept Power Elect, D-8000 Munich, Germany. RP Shul, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1998 VL 42 IS 12 BP 2117 EP 2117 PG 1 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 147NM UT WOS:000077573500001 ER PT J AU Ren, F Abernathy, CR MacKenzie, JD Gila, BP Pearton, SJ Hong, M Marcus, MA Schurman, MJ Baca, AG Shul, RJ AF Ren, F Abernathy, CR MacKenzie, JD Gila, BP Pearton, SJ Hong, M Marcus, MA Schurman, MJ Baca, AG Shul, RJ TI Demonstration of GaN MIS diodes by using AlN and Ga2O3(Gd2O3) as dielectrics SO SOLID-STATE ELECTRONICS LA English DT Article ID MOLECULAR-BEAM EPITAXY; DEVICES; INGAN AB GaN MIS diodes were demonstrated utilizing AlN and Ga2O3(Gd2O3) as insulators. A 345 Angstrom of AlN was grown on the MOCVD grown n-GaN in a MOMBE system using trimethylamine alane as Al precursor and nitrogen generated from a SVT RF N-2 plasma. For the Ga2O3(Gd2O3) growth, a multi-MBE chamber was used and a 195 Angstrom oxide was E-beam evaporated from a single crystal source of Ga5Gd3O12 The forward breakdown voltage of AIN and Ga2O3(Gd2O3) diodes are 5 and 6 V, respectively, which are significantly improved over similar to 1.2 V from that of a Schottky contact. From the C-V measurements, both kinds of diodes showed good charge modulation From accumulation to depletion at different frequencies. The insulator/GaN interface roughness and the thickness of the insulator were measured with X-ray reflectivity. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Chem Engn, Gainesville, FL 32611 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. EMCORE Inc, Somerset, NJ 07061 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Univ Florida, Dept Chem Engn, POB 116005, Gainesville, FL 32611 USA. RI Hong, Minghwei/C-1433-2010 NR 16 TC 43 Z9 43 U1 2 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 EI 1879-2405 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1998 VL 42 IS 12 BP 2177 EP 2181 DI 10.1016/S0038-1101(98)00213-5 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 147NM UT WOS:000077573500008 ER PT J AU Shul, RJ Vawter, GA Willison, CG Bridges, MM Lee, JW Pearton, SJ Abernathy, CR AF Shul, RJ Vawter, GA Willison, CG Bridges, MM Lee, JW Pearton, SJ Abernathy, CR TI Comparison of plasma etch techniques for III-V nitrides SO SOLID-STATE ELECTRONICS LA English DT Article ID LIGHT-EMITTING DIODES; GAN; CL-2/AR; BCL3; ALN; INN AB Fabrication of group-III nitride devices relies on the ability to pattern features to depths ranging from similar to 1000 A to > 5 mu m with anisotropic profiles, smooth morphologies, selective etching of one material over another and a low degree of plasma-induced damage. In this study, GaN etch rates and etch profiles are compared using reactive ion etch (RIE), reactive ion beam etching (RIBE), electron cyclotron resonance (ECR) and inductively coupled plasma (ICP) etch systems. RIE yielded the slowest etch rates and sloped etch profiles despite de-biases > -900 V. ECR and ICP etching yielded the highest rates with anisotropic profiles due to their high plasma flux and the ability to control ion energies independently of plasma density. RIBE etch results also showed anisotropic profiles but with slower etch rates than either ECR or ICP possibly due to lower ion flux. InN and AlN etch characteristics are also compared using ICP and RIBE. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Shul, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 16 TC 35 Z9 35 U1 1 U2 23 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1998 VL 42 IS 12 BP 2259 EP 2267 DI 10.1016/S0038-1101(98)00223-8 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 147NM UT WOS:000077573500018 ER PT J AU Shul, RJ Willison, CG Bridges, MM Han, J Lee, JW Pearton, SJ Abernathy, CR MacKenzie, JD Donovan, SM AF Shul, RJ Willison, CG Bridges, MM Han, J Lee, JW Pearton, SJ Abernathy, CR MacKenzie, JD Donovan, SM TI High-density plasma etch selectivity for the III-V nitrides SO SOLID-STATE ELECTRONICS LA English DT Article ID GAN; CL-2/AR; ALN; INN AB High-density plasma etching has been an effective patterning technique for the group-III nitrides due to ion fluxes which are 2-4 orders of magnitude higher than more conventional reactive ion etch (RIE) systems. GaN etch rates exceeding 0.68 mu m/min have been reported in Cl-2/H-2/Ar inductively coupled plasmas (ICP) at -280 V dc-bias. Under these conditions, the etch mechanism is dominated by ion bombardment energies which can induce damage and minimize etch selectivity. High selectivity etch processes are often necessary for heterostructure devices which are becoming more prominent as growth techniques improve. In this study, we will report high-density ICP etch rates and selectivities for GaN, AlN, and InN as a function of plasma chemistry, cathode rf-power, ICP-source power, and chamber pressure. GaN:AlN selectivities >8:1 were observed in a Cl-2/Ar plasma at 10 mTorr pressure, 500 W ICP-source power, and 130 W cathode rf-power, while the GaN:InN selectivity was optimized at similar to 6.5:1 at 5 mTorr, 500 W ICP-source power, and 130 W cathode rf-power. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Shul, RJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 18 TC 32 Z9 34 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1998 VL 42 IS 12 BP 2269 EP 2276 DI 10.1016/S0038-1101(98)00224-X PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 147NM UT WOS:000077573500019 ER PT J AU Cho, H Vartuli, CB Abernathy, CR Donovan, SM Pearton, SJ Shul, RJ Han, J AF Cho, H Vartuli, CB Abernathy, CR Donovan, SM Pearton, SJ Shul, RJ Han, J TI Cl-2-based dry etching of the AlGaInN system in inductively coupled plasmas SO SOLID-STATE ELECTRONICS LA English DT Article ID FIELD-EFFECT TRANSISTORS; MOLECULAR-BEAM EPITAXY; OHMIC CONTACTS; GAN; INN; NITRIDE; PERFORMANCE; GROWTH; INALN; CL2 AB Cl-2-Based inductively coupled plasmas with low additional d.c. self-biases (-100 V) produce convenient etch rates (500-1500 Angstrom.min(-1)) for GaN, AlN, InN, InAlN and InGaN. A systematic study of the effects of additive gas (Ar, N-2 H-2), discharge composition and ICP source power and chuck power on etch rate and surface morphology has been performed. The general trends are to go through a maximum in etch rate with percent Cl-2 in the discharge for all three mixtures and to have an increase (decrease) in etch rate with source power (pressure). Since the etching is strongly ion-assisted, anisotropic pattern transfer is readily achieved. Maximum etch selectivities of approximately 6 for InN over the other nitrides were obtained. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cho, H (reprint author), Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. NR 25 TC 15 Z9 16 U1 2 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1998 VL 42 IS 12 BP 2277 EP 2281 DI 10.1016/S0038-1101(98)00225-1 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 147NM UT WOS:000077573500020 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 ICP etching of SiC SO SOLID-STATE ELECTRONICS LA English DT Article ID CYCLOTRON-RESONANCE PLASMA; SILICON-CARBIDE; POWER DEVICES; SEMICONDUCTOR; NF3; 6H AB A number of different plasma chemistries, including NF3/O-2, SF6/O-2, SF6/Ar, ICI, IBr, Cl-2/Ar, BCl3/Ar and CH4/H-2/Ar, have been investigated for dry etching of 6H and 3C-SiC in an inductively coupled plasma tool. Rates above 2000 Angstrom cm(-1) are found with fluorine-based chemistries at high ion currents. Surprisingly, Cl-2-based etching does not provide high rates, even though the potential etch products (SiCl4 and CCl4) are volatile. Photoresist masks have poor selectivity over SiC in F-2-based plasmas under normal conditions. and ITO or Ni is preferred. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. 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. Univ Florida, Dept Chem Engn, Gainesville, FL 32611 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 39 TC 44 Z9 47 U1 2 U2 22 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD DEC PY 1998 VL 42 IS 12 BP 2283 EP 2288 DI 10.1016/S0038-1101(98)00226-3 PG 6 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA 147NM UT WOS:000077573500021 ER PT J AU Doeff, MM Reed, JS AF Doeff, MM Reed, JS TI Li ion conductors based on laponite/poly(ethylene oxide) composites SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT 11th International Conference on Solid State Ionics (SSI-11) CY NOV 16-21, 1997 CL HONOLULU, HI SP Int Soc Solid State Ion, Univ Hawaii, Coll Engn ID SILICATES AB Synthesis and characterization of single-ion conducting poly(ethylene oxide) (PEO)/Li-laponite nanocomposites are reported. The amount of PEO that can be intercalated into laponite, a synthetic hectorite with high surface area, ranges from about 0.7 g/g Li-laponite when the polymer average molecular weight is 1000 or above, to about 1 g/g for oligomers of average molecular weight 500. The interlayer spacing increases from al,out 10 Angstrom in the dry clay to 20-24 Angstrom in the nanocomposites, depending upon polymer molecular weight,;and the average particle size increases proportionally, but is still in the sub-micron range. AC impedance measurements on the clear, slightly brittle, self-supporting films indicate that the nanocomposite conductivity is greatly enhanced over that of the dry clay. A maximum of about 10(-6) S/cm at 80 degrees C is obtained for materials containing a slight excess of polymer, and conductivities of nanocomposites containing PEO were generally higher than that of those containing oxymethylene-linked polyethylene glycols (amorphous PEOs). Suggestions for further improving conductivity and mechanical properties of these novel materials are presented. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Doeff, MM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM doeff@CSA1.LBL.gov RI Doeff, Marca/G-6722-2013 OI Doeff, Marca/0000-0002-2148-8047 NR 13 TC 44 Z9 45 U1 3 U2 13 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 DEC PY 1998 VL 113 SI SI BP 109 EP 115 DI 10.1016/S0167-2738(98)00367-1 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 154BU UT WOS:000077868800017 ER PT J AU Paddison, SJ Zawodzinski, TA AF Paddison, SJ Zawodzinski, TA TI Molecular modeling of the pendant chain in Nafion (R) SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT 11th International Conference on Solid State Ionics (SSI-11) CY NOV 16-21, 1997 CL HONOLULU, HI SP Int Soc Solid State Ion, Univ Hawaii, Coll Engn DE Nafion (R); molecular modeling; solvation; electronic structure calculations; molecular dynamics; water; ion transport ID CLASSICAL ELECTROSTATICS; POLYMER ELECTROLYTES; SOLVATION MODELS; WATER-UPTAKE; MEMBRANES; TRANSPORT; DENSITY AB Ion transport through perfluorosulfonic acid ionomers such as Nafion(R) is controlled by both the microstructure of the polymer and the charge and water distribution in the hydrated polymer. We present here the results of theoretical calculations on the side chain of Nafion(R), establishing microscopic information for the modeling of water and proton transport in the membrane. Optimized geometries for the trifluoromethane sulfonic acid fragment (CF3SO3H), the di-trifluoromethane ether fragment (CF3OCF3), and the side chain (CF3-OCF2CF(CF3)OCF2CF2SO3H) were determined by means of both ab initio Hartree Fock theory with second order Moller-Plesset electron correlation corrections, and density functional theory with Becke's three parameter hybrid method. Several rotational potential energy surfaces were calculated to assess chain flexibility and proton accessibility. A probe water molecule was added to each of the fragments to characterize hydrophilic sites. These calculations confirmed that the sulfonic acid group is hydrophilic and the ethers are hydrophobic. Molecular dynamics simulations were then performed on the side chain to check the conditions required to stretch the pendant chain. Thermal averages of several structural parameters assessing the flexibility and stretch of the chain were computed from selected conformations produced in the simulation and these results indicate that although the sulfonate group is free to rotate, the chain stretches little. The construction of a potential energy surface for rotation about the second ether group suggests that the side chain exists in a folded or curled up conformation. A physical continuum dielectric solvent model was used to obtain free energies of electrostatic interaction of the fragments and the full chain with the solvent. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Paddison, SJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. EM paddison@lanl.gov RI Paddison, Stephen/B-2935-2014 NR 30 TC 114 Z9 115 U1 1 U2 25 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 DEC PY 1998 VL 113 SI SI BP 333 EP 340 DI 10.1016/S0167-2738(98)00298-7 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 154BU UT WOS:000077868800047 ER PT J AU McGraw, JM Perkins, JD Zhang, JG Liu, P Parilla, PA Turner, J Schulz, DL Curtis, CJ Ginley, DS AF McGraw, JM Perkins, JD Zhang, JG Liu, P Parilla, PA Turner, J Schulz, DL Curtis, CJ Ginley, DS TI Next generation V2O5 cathode materials for Li rechargeable batteries SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT 11th International Conference on Solid State Ionics (SSI-11) CY NOV 16-21, 1997 CL HONOLULU, HI SP Int Soc Solid State Ion, Univ Hawaii, Coll Engn DE vanadium oxide; charge capacity stability; structural transitions; amorphous; Raman spectroscopy; XRD ID LITHIUM AB We report on investigations of vanadium oxide thin film cathodes prepared by three different synthesis techniques. Our experimental results on PLD-grown, textured V2O5 crystalline: films concur with reports in the literature that there is a voltage threshold above which, cycling appears to be completely reversible and below which, cycling appears to be irreversible. Crystalline films discharged beyond the threshold to 2.0 V exhibited an immediate and continuous fade in capacity as well as a nearly 90% decrease in XRD peak intensity and a similar decrease in Raman signal intensity in as few as ten cycles. PLD-grown amorphous films show capacity loss of <2% over 200 cycles. Amorphous plasma-enhanced chemical vapor deposition (PECVD) films have capacities as :high as 1.5 Li/V with excellent stability over 3000 cycles. Solution-grown nanoparticles (<100 nm) of VO2 were spray-deposited and sintered at relatively low temperatures to produce nanoporous films. Cycling properties along with structural investigations by XRD and Raman scattering will be presented. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Colorado Sch Mines, Golden, CO 80401 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP McGraw, JM (reprint author), Colorado Sch Mines, Golden, CO 80401 USA. RI Liu, Ping/I-5615-2012 NR 6 TC 31 Z9 37 U1 1 U2 26 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 DEC PY 1998 VL 113 SI SI BP 407 EP 413 DI 10.1016/S0167-2738(98)00383-X PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 154BU UT WOS:000077868800057 ER PT J AU von Rottkay, K Richardson, T Rubin, M Slack, J Kullman, L AF von Rottkay, K Richardson, T Rubin, M Slack, J Kullman, L TI Influence of stoichiometry on electrochromic cerium-titanium oxide compounds SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT 11th International Conference on Solid State Ionics (SSI-11) CY NOV 16-21, 1997 CL HONOLULU, HI SP Int Soc Solid State Ion, Univ Hawaii, Coll Engn DE electrochromic cerium titanium oxide; optical constants; TiO2; bandgap; grain size; charge capacity; rms roughness ID ELECTRONIC-STRUCTURE; OPTICAL-PROPERTIES; TIO2 FILMS; REACTIVE EVAPORATION; RUTILE TIO2; THIN-FILMS; DIOXIDE; INDEXES AB CeO2-TiO2 finds use as passive counter-electrode in electrochromic devices. Thin films were produced by de-sputtering in a wide range of compositions. Influence of total pressure and oxygen partial pressure on the optical constants of TiO2 was investigated. Slightly substoichiometric TiO2 films exhibit a red-shift of the bandgap. The TiO2 content in the compound essentially determines the degree of cathodical coloring upon Li+ intercalation [1] [von Rottkay, K., Richardson, T., Rubin, M., Slack, I., Masetti, E., Dautzenberg, G., 1997. SPIE Proceedings 3138 9]. However, pure TiO2 films with comparable visible transmittance in the clear state behave differently during electrochemical cycling depending on oxygen stoichiometry. Films that are deposited at higher total pressure are more oxygen rich and require initial formatting until current voltage cycles become stable. CeO2-TiO2 films of intermediate compositions have the relatively highest charge capacity. Comparison with atomic force microscopy indicates a correlation of small grain size with high charge capacity. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Uppsala, S-75121 Uppsala, Sweden. RP von Rottkay, K (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM KvonRottkay@lbl.gov NR 19 TC 5 Z9 5 U1 0 U2 1 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 DEC PY 1998 VL 113 SI SI BP 425 EP 430 DI 10.1016/S0167-2738(98)00307-5 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 154BU UT WOS:000077868800060 ER PT J AU Stevenson, JW Armstrong, TR Pederson, LR Li, J Lewinsohn, CA Baskaran, S AF Stevenson, JW Armstrong, TR Pederson, LR Li, J Lewinsohn, CA Baskaran, S TI Effect of A-site cation nonstoichiometry on the properties of doped lanthanum gallate SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT 11th International Conference on Solid State Ionics (SSI-11) CY NOV 16-21, 1997 CL HONOLULU, HI SP Int Soc Solid State Ion, Univ Hawaii, Coll Engn DE lanthanum gallate; ionic conductivity; electronic conductivity; mechanical properties ID PEROVSKITE-TYPE OXIDE; LAGAO3-BASED ELECTROLYTE; ELECTRICAL-PROPERTIES; CATHODE MATERIALS; FUEL-CELL; CONDUCTIVITY; SYSTEM; PHASES AB Lanthanum gallate doped with Sr and Mg (LSGM) was synthesized using a combustion synthesis technique. The synthesized powders were sintered to high density in air, although excessively high sintering temperatures led to bloating of samples, possibly due to the volatilization of Ga2O from the perovskite structure. The electrical conductivity of sintered LSGM tended to decrease with increasing A/B cation nonstoichiometry. Under oxidizing conditions, the conductivity was almost completely ionic, but in reducing atmospheres a substantial electronic component was observed. It is likely that this electronic conduction resulted from the introduction of electronic charge carriers via the partial reduction of Ga from the trivalent to the divalent state. The flexural strength of LSGM with an A/B cation ratio of 1.00 was measured to be similar to 150 MPa at room temperature; the strength decreased to similar to 100 MPa at higher temperatures (600-1000 degrees C). The fracture toughness, as measured by notched beam analysis, was similar to 2.0-2.2 MPa root m at room temperature, decreasing to similar to 1.0 MPa root m at 1000 degrees C. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Pacific NW Natl Lab, Dept Chem & Mat Sci, Richland, WA 99352 USA. RP Stevenson, JW (reprint author), Pacific NW Natl Lab, Dept Chem & Mat Sci, POB 999,MS K2-44, Richland, WA 99352 USA. EM jw_stevenson@pnl.gov RI pelosato, renato/E-9950-2010 NR 37 TC 135 Z9 139 U1 1 U2 23 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 DEC PY 1998 VL 113 SI SI BP 571 EP 583 DI 10.1016/S0167-2738(98)00324-5 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 154BU UT WOS:000077868800081 ER PT J AU Gregory, DM Benzinger, TLS Burkoth, TS Miller-Auer, H Lynn, DG Meredith, SC Botto, RE AF Gregory, DM Benzinger, TLS Burkoth, TS Miller-Auer, H Lynn, DG Meredith, SC Botto, RE TI Dipolar recoupling NMR of biomolecular self-assemblies: determining inter- and intrastrand distances in fibrilized Alzheimer's beta-amyloid peptide SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE dipolar recoupling NMR; beta-amyloid peptide; Alzheimer's disease ID SOLID-STATE NMR; DOUBLE-RESONANCE NMR; ROTATIONAL RESONANCE; MOLECULAR-STRUCTURE; PLAQUE COMPETENCE; AMINO-ACIDS; PROTEIN; DISEASE; SPECTROSCOPY; CONFORMATION AB We demonstrate a new method for investigating the structure of self-associating biopolymers using dipolar recoupling NMR techniques. This approach was applied to the study of fibrillar beta-amyloid (A beta) peptides (the primary component of the plaques of Alzheimer's disease) containing only a single isotopic spin label (C-13), by employing the DRAWS (dipolar recoupling with a windowless sequence) technique to measure C-13-C-13 distances. The 'single-label' approach simplified analysis of DRAWS data, since only interstrand contacts are present, without the possibility of any intrastrand contacts. As previously reported [T.L.S. Benzinger, D.M. Gregory, T.S. Burkoth, H. Miller-Auer, D.G. Lynn, R.E. Botto, S.C. Meredith, (1998) 13407.], contacts of approximately 5 Angstrom were observed at all residues studied; consistent with an extended parallel beta-sheet structure with each amino acid in exact register. Here, we propose that our strategy is completely generalizable, and provides a new approach for characterizing any iterative, self-associating biopolymer. Towards the end of generalizing and refining our approach, in this paper we evaluate several issues raised by our previous analyses. First, we consider the effects of double-quantum (DQ) transverse relaxation processes. Next, we discuss the effects of various multiple-spin geometries on modeling of DRAWS data. Several practical issues are also discussed: these include (1) the use of DQ filtering experiments, either to corroborate DRAWS data, or as a rapid screening assessment of the proper placement of isotopic spin labels; and (2) the comparison of solid samples prepared by either lyophilization or freezing. Finally, data obtained from the use of single labels is compared with that obtained in doubly C-13-labeled model compounds of known crystal structure. It is shown that such data are obtainable in far more complex peptide molecules. These data,taken together, refine the DRAWS method, and demonstrate its precision and utility in obtaining high resolution structural data in complex biomolecular aggregates such as A beta. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. Univ Chicago, Dept Chem, Chicago, IL 60637 USA. RP Botto, RE (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM dlynn@midway.uchicago.edu; scmeredi@midway.uchicago.edu; robert_botto@qmgate.anl.gov FU NCRR NIH HHS [R21 RR 12723]; NHLBI NIH HHS [5 T32 HL07327]; NIGMS NIH HHS [5 T32 GM07281] NR 47 TC 69 Z9 70 U1 4 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD DEC PY 1998 VL 13 IS 3 BP 149 EP 166 DI 10.1016/S0926-2040(98)00086-1 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA 161QW UT WOS:000078301300002 PM 10023844 ER PT J AU Zhang, XF AF Zhang, XF TI Geometry of domain boundaries in five-domain YBa2Cu3Oy levitators fabricated by seeded melt processing SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID THIN-FILMS; SINGLE-DOMAIN; GROWTH; MICROSTRUCTURE; YBCO AB Large-diameter five-domain YBa2Cu3Oy (YBCO) cylindrical pellets were produced by a seeded melt-texturing process in a purpose of magnetic levitation applications. Transmission electron microscopy and polarized optical microscopy were utilized to characterize the boundary geometry in the YBCO pellets. In addition to the well-known symmetrical 90 degrees tilt domain boundaries, asymmetrical 90 degrees tilt boundaries have been observed to form the faceted boundary segments. Although the faceted boundaries are based on a basal-plane-faced boundary structure which can in principle lower the supercurrent density, the twist component formed in the boundary area may largely benefit the current transport therefore make the faceted boundary segments not so harmful to the transport property. Nevertheless, microcracks can be induced around the faceted boundaries by thermal cycles, resulting in the decreased levitation force. In this sense, faceted boundary segments should be reduced to a minimum in levitation products. C1 Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Zhang, XF (reprint author), Lawrence Berkeley Lab, Div Mat Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 21 TC 5 Z9 5 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD DEC PY 1998 VL 11 IS 12 BP 1391 EP 1396 DI 10.1088/0953-2048/11/12/007 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 148VG UT WOS:000077553800007 ER PT J AU Goretta, KC Kupperman, DS Majumdar, S Such, MW Murayama, N AF Goretta, KC Kupperman, DS Majumdar, S Such, MW Murayama, N TI Elastic constants of dense, textured (Bi, Pb)(2)Sr2Ca2Cu3Oy SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID NONLINEAR ACOUSTIC PROPERTIES; CU-O SUPERCONDUCTORS; BI2SR2CACU2O8+Y; ANISOTROPY AB We fabricated a dense, bulk (Bi, Pb)(2)Sr2Ca2Cu3Oy (Bi-2223) bar by sinter forging. The bar exhibited excellent phase purity and strong texture of the c axes preferentially aligned parallel to the forging direction. Elastic constants were obtained at room temperature; one elastic constant was also measured to 760 degrees C. Bi-2223 proved to be approximate to 25-30% stiffer than Bi2Sr2CaCu2Ox. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. Natl Ind Res Inst Nagoya, Nagoya, Aichi 4628510, Japan. RP Goretta, KC (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 14 TC 8 Z9 8 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD DEC PY 1998 VL 11 IS 12 BP 1409 EP 1411 DI 10.1088/0953-2048/11/12/010 PG 3 WC Physics, Applied; Physics, Condensed Matter SC Physics GA 148VG UT WOS:000077553800010 ER PT J AU Hannon, JB Kellogg, GL Bartelt, MC Bartelt, NC AF Hannon, JB Kellogg, GL Bartelt, MC Bartelt, NC TI Quantitative analysis of the evolution of surface growth morphology in LEEM SO SURFACE REVIEW AND LETTERS LA English DT Article AB We describe Monte Carlo simulations and diffusion equation analysis which are useful in deriving kinetic parameters from low energy electron microscopy experiments. An analysis of the etching of the Si(001) surface with molecular oxygen is made, illustrating the power of these techniques. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Hannon, JB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 4 TC 0 Z9 0 U1 2 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD DEC PY 1998 VL 5 IS 6 BP 1151 EP 1158 DI 10.1142/S0218625X98001481 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 167LZ UT WOS:000078635900004 ER PT J AU Hannon, JB Swartzentruber, BS Kellogg, GL Bartelt, NC AF Hannon, JB Swartzentruber, BS Kellogg, GL Bartelt, NC TI LEEM measurements of step energies at the (001) surface of heavily boron-doped silicon SO SURFACE REVIEW AND LETTERS LA English DT Article ID SI(100); SI(001); STRESS; PHASE AB We have used the low energy electron microscope (LEEM) to investigate step faceting and striped phase formation on heavily boron-doped Si(001) surfaces. Measurements of thermal fluctuations along the steps, equilibrium island shapes, and the angle of triangular facets provide quantitative information on the step formation energies. We find that a simple, systematic temperature dependence of the spatial anisotropy of the free energy of isolated steps is sufficient to account for the observed faceting of the B type steps. These results suggest that the proliferation of straight A step edges at lower temperature is caused by the energy of isolated A steps becoming vanishingly small. We show that rapid cooling of the samples leads to the nucleation and growth of a high density of vacancy islands on the surfaces. Based on these results, we propose a qualitative model for mass transport during stripe formation. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Hannon, JB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 6 Z9 6 U1 0 U2 5 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD DEC PY 1998 VL 5 IS 6 BP 1159 EP 1165 DI 10.1142/S0218625X98001493 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 167LZ UT WOS:000078635900005 ER PT J AU Stohr, J Padmore, HA Anders, S Stammler, T Scheinfein, MR AF Stohr, J Padmore, HA Anders, S Stammler, T Scheinfein, MR TI Principles of X-ray magnetic dichroism spectromicroscopy SO SURFACE REVIEW AND LETTERS LA English DT Article ID CIRCULAR-DICHROISM; ABSORPTION-SPECTRA; PHOTOEMISSION MICROSCOPE; TRANSITION-METALS; SPIN; SPECTROSCOPY; DOMAINS; PROBE; IRON AB A review is given of the principles underlying X-ray magnetic circular (XMCD) and linear (XMLD) dichroism spectromicroscopies consisting of polarized X-ray absorption spectroscopy in conjunction with scanning or imaging microscopy. The techniques are shown to have many useful and important capabilities for the study of complex magnetic materials. They offer elemental specificity, chemical specificity and variable depth sensitivity, among others. XMCD microscopy is best suited for the study of ferromagnets and ferrimagnets, and it allows a quantitative determination of the size and direction of spin and orbital moments. XMLD microscopy promises to become a powerful tool for the study of antiferromagnets which are difficult to study by conventional microscopy techniques. C1 IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. RP Stohr, J (reprint author), IBM Corp, Almaden Res Ctr, Div Res, 650 Harry Rd, San Jose, CA 95120 USA. RI Raoux, Simone/G-3920-2016 NR 44 TC 122 Z9 123 U1 7 U2 60 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD DEC PY 1998 VL 5 IS 6 BP 1297 EP 1308 DI 10.1142/S0218625X98001638 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 167LZ UT WOS:000078635900019 ER PT J AU Wang, D Karle, R Brettin, TS Iezzoni, AF AF Wang, D Karle, R Brettin, TS Iezzoni, AF TI Genetic linkage map in sour cherry using RFLP markers SO THEORETICAL AND APPLIED GENETICS LA English DT Article DE Prunus; Prunus cerasus; polyploid linkage map ID RAPD MARKERS; PEACH; INHERITANCE; FRAGMENTS; ISOZYME; ALMOND AB Restriction fragment length polymorphism (RFLP) linkage maps of two tetraploid sour cherry (Prunus cerasus L., 2n = 4x = 32) cultivars, Rheinische Schattenmorelle (RS) and Erdi Botermo (EB), were constructed from 86 progeny from the cross RS x EB. The RS linkage map consists of 126 single-dose restriction fragment (SDRF, Wu et al. 1992) markers assigned to 19 linkage groups covering 461.6 cM. The EB linkage map has 95 SDRF markers assigned to 16 linkage groups covering 279.2 cM. Fifty three markers mapped in both parents were used as bridges between both maps and 13 sets of homologous linkage groups were identified. Homoeologous relationships among the sour cherry linkage groups could not be determined because only 15 probes identified duplicate loci. Fifty nine of the markers on the linkage maps were detected with probes used in other Prunus genetic linkage maps. Four of the sour cherry linkage groups may be homologous with four of the eight genetic linkage groups identified in peach and almond. Twenty one fragments expected to segregate in a 1 : 1 ratio segregated in a 2 : 1 ratio. Three of these fragments were used in the final map construction because they all mapped to the same linkage group. Six fragments exhibited segregation consistent with the expectations of intergenomic pairing and/or recombination. C1 Michigan State Univ, Dept Hort, E Lansing, MI 48824 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Iezzoni, AF (reprint author), Michigan State Univ, Dept Hort, E Lansing, MI 48824 USA. NR 18 TC 42 Z9 53 U1 1 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0040-5752 J9 THEOR APPL GENET JI Theor. Appl. Genet. PD DEC PY 1998 VL 97 IS 8 BP 1217 EP 1224 DI 10.1007/s001220051013 PG 8 WC Agronomy; Plant Sciences; Genetics & Heredity; Horticulture SC Agriculture; Plant Sciences; Genetics & Heredity GA 150LP UT WOS:000077666600004 ER PT J AU Nicklass, A Peterson, KA AF Nicklass, A Peterson, KA TI Core-valence correlation effects for molecules containing first-row atoms. Accurate results using effective core polarization potentials SO THEORETICAL CHEMISTRY ACCOUNTS LA English DT Article DE core-valence correlation; core polarization potentials ID CONFIGURATION-INTERACTION CALCULATIONS; GROUND-STATE PROPERTIES; DIPOLE-MOMENT FUNCTIONS; ALKALINE-EARTH ATOMS; GAUSSIAN-BASIS SETS; SPECTROSCOPIC CONSTANTS; PSEUDOPOTENTIAL CALCULATIONS; WAVE-FUNCTIONS; BENCHMARK CALCULATIONS; DISSOCIATION-ENERGY AB The accuracy of employing effective core polarization potentials (CPPs) to account for the effects of core-valence correlation on the spectroscopic constants and dissociation energies of the molecules B-2, C-2, N-2, O-2, F-2, CO, CN, CH, HF, and C2H2 has been investigated by comparison to accurate all-electron benchmark calculations. The results obtained fi-om the calculations employing CPPs were surprisingly accurate in every case studied, reducing the errors in the calculated valence D-e values from a maximum of nearly 2.5 kcal/mol to just 0.3 kcal/mol. The effects of enlarging the basis set and using higher-order valence electron correlation treatments were found to have only a small influence on the core-valence correlation effect predicted by the CPPs. Thus, to accurately recover the effects of intershell correlation, effective core polarization potentials such as the ones used in the present work provide an attractive alternative to carrying out computationally demanding calculations where the core electrons are explicitly included in the correlation treatment. C1 Washington State Univ, Dept Chem, Richland, WA 99352 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Peterson, KA (reprint author), Washington State Univ, Dept Chem, Richland, WA 99352 USA. NR 60 TC 6 Z9 6 U1 0 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 1432-881X J9 THEOR CHEM ACC JI Theor. Chem. Acc. PD DEC 1 PY 1998 VL 100 IS 1-4 BP 103 EP 111 DI 10.1007/s002140050370 PG 9 WC Chemistry, Physical SC Chemistry GA 144ZL UT WOS:000077346100012 ER PT J AU Dill, JA Lee, KM Bates, DJ Anderson, DJ Johnson, RE Chou, BJ Burka, LT Roycroft, JH AF Dill, JA Lee, KM Bates, DJ Anderson, DJ Johnson, RE Chou, BJ Burka, LT Roycroft, JH TI Toxicokinetics of inhaled 2-butoxyethanol and its major metabolite, 2-butoxyacetic acid, in F344 rats and B6C3F1 mice SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article ID GLYCOL MONOBUTYL ETHER; PHYSIOLOGICALLY-BASED PHARMACOKINETICS; ALDEHYDE DEHYDROGENASE-ACTIVITIES; BUTOXYACETIC ACID; BUTYL ETHER; TOXICITY; HUMANS; ABSORPTION; ALCOHOL; VAPOR AB 2-Butoxyethanol (2BE) is used extensively in the production of cleaning agents and solvents. It is primarily metabolized in the liver to 2-butoxyacetic acid (2BAA), which is believed to be responsible for 2BE toxicities associated with hemolysis of red blood cells. The objective of the study was to characterize the systemic disposition of 2BE and 2BAA in rats and mice during 2-year 2BE inhalation toxicity studies. Male and female F344 rats and B6C3F1 mice (6-7 weeks old) were exposed to target 2BE concentrations of 0, 31.2, 62.5, or 125 ppm (rats), or 0, 62.5, 125, or 250 ppm (mice), by whole-body inhalation for 6 h/day, 5 days/ week far up to 18 months. Postexposure blood samples were collected after 1 day, 2 weeks, and 3, 6, 12, and 18 months of exposure. Postexposure 16-h urine samples were collected after 2 weeks and 3, 6, 12, and 18 months of exposure. A separate set of mice was kept in the control chamber and exposed to 2BE for 3 weeks when they were approximately 19 months old. Postexposure blood samples were collected after 1 day and 3 weeks of exposure and 16-h urine samples were collected after 2 weeks of exposure from these aged mice. Blood samples were analyzed for both 2BE and 2BAA and urine samples were analyzed for 2BAA using GC/MS, and their kinetic parameters were estimated through the curve-fitting method using SAS. Systemically absorbed 2BE was rapidly cleared from blood (t(1/2-RAT) < 10 min; t(1/2-MOUSE) < 5 min after the 1-day exposure) independent of exposure concentration. proportional increases in AUC(2BE) relative to increases in exposure concentration indicated linear 2BE kinetics. In contrast, the rate of 2BAA elimination from blood decreased as the exposure concentration increased. Nonproportional increases in AUC(2BAA) also indicated that 2BAA is eliminated following dose-dependent, nonlinear kinetics. Overall, mice eliminated both 2BE and 2BAA from blood faster than rats. Sex-related differences in 2BAA elimination were most significant with rats, in that females were less efficient in clearing 2BAA from the blood. Differences in renal excretion of 2BAA are possibly responsible for the sex-related difference in the 2BAA blood profiles in rats. As exposure continued, the rates of elimination for both 2BE and 2BAA decreased in both species, resulting in longer residence times in the blood. When 19-month-old naive mice were exposed to 125 ppm, 2BE was rapidly cleared from the systemic circulation, exhibiting clearance profiles similar to young mice. However, old mice eliminated 2BAA from blood > 10 times slower than young mice after 1-day of exposure. This delayed elimination of 2BAA in old mice was less obvious after 3 weeks of exposure, suggesting that there might be other factors in addition to the age of animals that could influence the apparent difference in 2BAA kinetics between old and young mice. It was concluded that the elimination kinetics of 2BE and 2BAA following repeated 2BE exposure appear to be dependent on species, sex, age, time of exposure, as well as the exposure concentration. (C) 1998 Academic Press. C1 Pacific NW Lab, Preclin Drug Dev NW Operat, Richland, WA 99352 USA. Pacific NW Lab, Engn & Analyt Sci Dept, Richland, WA 99352 USA. NIEHS, Res Triangle Pk, NC 27709 USA. RP Dill, JA (reprint author), Pacific NW Lab, Preclin Drug Dev NW Operat, Richland, WA 99352 USA. NR 34 TC 14 Z9 16 U1 0 U2 0 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD DEC PY 1998 VL 153 IS 2 BP 227 EP 242 DI 10.1006/taap.1998.8524 PG 16 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA 156WG UT WOS:000078024700009 PM 9878593 ER PT J AU Lemieux, GA Bertozzi, CR AF Lemieux, GA Bertozzi, CR TI Chemoselective ligation reactions with proteins, oligosaccharides and cells SO TRENDS IN BIOTECHNOLOGY LA English DT Review ID NATIVE CHEMICAL LIGATION; N-LINKED GLYCOPEPTIDES; ANTIBACTERIAL PEPTIDE; MONOCLONAL-ANTIBODIES; UNPROTECTED PEPTIDES; BUILDING-BLOCKS; L-SELECTIN; IN-VIVO; TUMOR; GLYCOSYLATION AB Traditional chemical synthesis does not lend itself to the easy, rapid construction of even moderately sized biomolecules, because it requires elaborate protection schemes. Furthermore, many biological studies would be aided by the ability to assemble biomolecules under physiological conditions. These challenges have motivated the development of chemoselective ligation, the selective covalent coupling of mutually and uniquely reactive functional groups under mild, aqueous conditions. This technique has attracted significant attention recently for the synthesis of biological macromolecules of defined homogeneous composition, the design of self-assembling drugs and the chemical remodeling of cell surfaces. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Lemieux, GA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. FU NIGMS NIH HHS [GM08352] NR 74 TC 180 Z9 187 U1 1 U2 24 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0167-7799 J9 TRENDS BIOTECHNOL JI Trends Biotechnol. PD DEC PY 1998 VL 16 IS 12 BP 506 EP 513 DI 10.1016/S0167-7799(98)01230-X PG 8 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA 147AP UT WOS:000077466300003 PM 9881482 ER PT J AU Larson, DJ Foord, DT Petford-Long, AK Anthony, TC Rozdilsky, IM Cerezo, A Smith, GWD AF Larson, DJ Foord, DT Petford-Long, AK Anthony, TC Rozdilsky, IM Cerezo, A Smith, GWD TI Focused ion-beam milling for field-ion specimen preparation: preliminary investigations SO ULTRAMICROSCOPY LA English DT Article DE field-ion microscopy; specimen preparation and handling ID ATOM-PROBE ANALYSIS; THIN-FILMS; MULTILAYERS; MICROSCOPY; TUNGSTEN AB Focused ion-beam milling has been used to fabricate field-ion specimens from a pure metal, a metal alloy, an intermetallic alloy and a multilayer film device. Gallium ions of 30 keV energy with beam currents of 4-1000 pA were used for micromachining of the field-ion specimens and for simultaneous imaging. The final sharpening for pure metal and intermetallic specimens and the entire sharpening procedure for a metal alloy sample and a multilayer film structure containing 100 repetitions of a Cu-2 nm/Co-2 (nm) bilayer were accomplished using the focused ion-beam system, Atom probe analysis indicated that although the amount of gallium implantation was minimal in a Cu-15% Co alloy, significant damage occurred in Cu/Co multilayer film structures prepared by focused ion-beam milling. Focused ion-beam techniques provide an alternative to traditional electropolishing methods for field-ion specimen preparation and atom probe analysis provides quantitative information of implanted gallium and ion-induced damage in such samples. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Oxford, Dept Mat, Oxford OX1 3PH, England. Univ Cambridge, Dept Mat Sci & Met, Cambridge CB2 3QZ, England. Hewlett Packard Labs, Palo Alto, CA 94304 USA. RP Larson, DJ (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008,MS 6376, Oak Ridge, TN 37831 USA. RI Petford-Long, Amanda/P-6026-2014 OI Petford-Long, Amanda/0000-0002-3154-8090 NR 39 TC 58 Z9 58 U1 3 U2 16 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD DEC PY 1998 VL 75 IS 3 BP 147 EP 159 DI 10.1016/S0304-3991(98)00058-8 PG 13 WC Microscopy SC Microscopy GA 149VJ UT WOS:000077626700002 ER PT J AU Glass, RJ Nicholl, MJ Yarrington, L AF Glass, RJ Nicholl, MJ Yarrington, L TI A modified invasion percolation model for low-capillary number immiscible displacements in horizontal rough-walled fractures: Influence of local in-plane curvature SO WATER RESOURCES RESEARCH LA English DT Article ID POROUS-MEDIA; FLOW; INSTABILITY; NETWORK; ROCK AB We develop and evaluate a modified invasion percolation (MIP) model for quasi-static immiscible displacement in horizontal fractures. The effects of contact angle, local aperture field geometry, and local in-plane interfacial curvature between phases are included in the calculation of invasion pressure for individual sites in a discretized aperture field. This pressure controls the choice of which site is invaded during the displacement process and hence the growth of phase saturation structure within the fracture. To focus on the influence of local in-plane curvature on phase invasion structure, we formulate a simplified nondimensional pressure equation containing a dimensionless curvature number (C) that weighs the relative importance of in-plane curvature and aperture-induced curvature. Through systematic Variation of C, we find in-plane interfacial curvature to greatly affect the phase invasion structure. As C is increased from zero, phase invasion fronts transition from highly complicated (IP results) to macroscopically smooth. In addition, measurements of fracture phase saturations and entrapped cluster statistics (number, maximum size, structural complication) show differential response between wetting and nonwetting invasion with respect to C that is independent of contact angle hysteresis. Comparison to experimental data available at this time substantiates predicted behavior. C1 Sandia Natl Labs, Flow Visualizat & Proc Lab, Albuquerque, NM 87185 USA. Oklahoma State Univ, Sch Geol, Stillwater, OK 74078 USA. RP Glass, RJ (reprint author), Sandia Natl Labs, Flow Visualizat & Proc Lab, POB 5800, Albuquerque, NM 87185 USA. NR 34 TC 59 Z9 60 U1 0 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC PY 1998 VL 34 IS 12 BP 3215 EP 3234 DI 10.1029/98WR02224 PG 20 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 145VV UT WOS:000077393000001 ER PT J AU Kneafsey, TJ Pruess, K AF Kneafsey, TJ Pruess, K TI Laboratory experiments on heat-driven two-phase flows in natural and artificial rock fractures SO WATER RESOURCES RESEARCH LA English DT Article ID STEADY-SOLUTION SELECTION; SANDY VADOSE ZONE; POROUS-MEDIA; THERMOHYDROLOGIC CONDITIONS; PREFERENTIAL FLOW; TUFF; VISUALIZATION; EXISTENCE; PIPES AB Water flow in partially saturated fractures under thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. At the potential high-level nuclear waste repository at Yucca Mountain, water flowing in fast pathways may ultimately contact waste packages and transport radionuclides to the accessible environment Sixteen experiments were conducted to visualize heat-driven liquid flow in fracture models that included (1) assemblies of roughened glass plates,. (2) epoxy replicas of rock fractures, and (3) a fractured specimen of Topopah Spring tuff. Continuous rivulet flow was observed for high liquid flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and him flow for lower flow rates and wide apertures. Heat pipe conditions (vapor-liquid counterflow with phase change) were identified in five of the seven experiments in which spatially resolved thermal monitoring was performed but not when vapor-liquid counterflow was hindered by very narrow apertures and when an inadequate working fluid volume was used. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RP Kneafsey, TJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Earth Sci, Berkeley, CA 94720 USA. RI Kneafsey, Timothy/H-7412-2014 OI Kneafsey, Timothy/0000-0002-3926-8587 NR 42 TC 20 Z9 21 U1 0 U2 8 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 DEC PY 1998 VL 34 IS 12 BP 3349 EP 3367 DI 10.1029/98WR02035 PG 19 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 145VV UT WOS:000077393000012 ER PT J AU Newman, BD Campbell, AR Wilcox, BP AF Newman, BD Campbell, AR Wilcox, BP TI Lateral subsurface flow pathways in a semiarid ponderosa pine hillslope SO WATER RESOURCES RESEARCH LA English DT Article ID NEW-MEXICO; PREFERENTIAL FLOW; RUNOFF GENERATION; WATER-MOVEMENT; SOIL; MACROPORES; CATCHMENT; DISCHARGE; SHALLOW; OLD AB The mechanisms controlling lateral subsurface flow in semiarid environments have received relatively little attention despite the fact that lateral subsurface flow can be an important runoff process in these environments. The objective of the current study is to better understand lateral subsurface flow process in semiarid environments. Natural chloride, dissolved organic carbon, and stable isotope (delta D and delta(18)O) tracers were used to investigate the lateral subsurface flow process and the chemical changes that occur as a result of lateral subsurface flow. Observed differences in chemistry between soil matrix water and lateral subsurface flow were large (for example, chloride concentrations in matrix soil water samples were >200 mg/L, compared with only 2 mg/L in lateral subsurface flow samples obtained at the same time). This difference in chemistry is indicative of a two-domain flow system in which macropores conduct lateral subsurface flow that is not in chemical or hydrological equilibrium with the soil matrix. The size of precipitation events appeared to have a strong influence on the variations in old/new water percentages, and examples of both old and new water dominated events were observed. There were also large variations in the chemistry of lateral subsurface flow with time. For example, chloride and dissolved organic carbon concentrations were 10 and 70 times greater, respectively, under saturated conditions than under unsaturated conditions. C1 New Mexico Inst Min & Technol, Earth & Environm Sci Dept, Socorro, NM 87801 USA. Univ Calif Los Alamos Natl Lab, Environm Sci Grp, Los Alamos, NM 87545 USA. RP Newman, BD (reprint author), New Mexico Inst Min & Technol, Earth & Environm Sci Dept, Socorro, NM 87801 USA. EM bnewman@lanl.gov NR 32 TC 76 Z9 77 U1 3 U2 13 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 DEC PY 1998 VL 34 IS 12 BP 3485 EP 3496 DI 10.1029/98WR02684 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 145VV UT WOS:000077393000022 ER PT J AU Keating, EH Bahr, JM AF Keating, EH Bahr, JM TI Using reactive solutes to constrain groundwater flow models at a site in northern Wisconsin SO WATER RESOURCES RESEARCH LA English DT Article ID SANDY SILICATE AQUIFER; CHEMICAL EVOLUTION; WATER; TRANSPORT; EXCHANGE; STREAM; ZONE AB We propose a method for constraining a groundwater flow model both by head observations and concentrations of nonconservative solutes such as calcium, using reaction-path modeling. When calibrating flow models in small watershed in northern Wisconsin using head data alone, we encountered problems of nonuniqueness. However, by coupling the flow models wi th a plagioclase dissolution model, we were able to greatly reduce the number of plausible flow models. First, by using flow modeling and reaction path modeling in parallel, we tested the consistency of residence times predicted by the flow models with solute concentrations predicted by the geochemical models. Mineral dissolution rate parameters were assumed to be spatially uniform; without this condition the geochemistry data would not provide additional constraints to the flow modeling process. For a more comprehensive test of our models, we used reactive-transport modeling to predict the spatial distribution of ions at each site. The models qualitatively reproduced the observed data and our calibrated silicate dissolution rates closely matched those reported in a field study of nearby site. There were also discrepancies between predictions and observations. We attribute these to transient effects and sediment heterogeneities that were not included in the models. While the resulting models are not unique, our approach demonstrates the ability of fairly simple models to explain much of the observed variability in a complex system. C1 Univ Calif Los Alamos Natl Lab, Geoanal Grp, Los Alamos, NM 87545 USA. Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. RP Keating, EH (reprint author), Univ Calif Los Alamos Natl Lab, Geoanal Grp, MS F665, Los Alamos, NM 87545 USA. RI Keating, Elizabeth/B-4678-2011 NR 27 TC 12 Z9 12 U1 0 U2 2 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 DEC PY 1998 VL 34 IS 12 BP 3561 EP 3571 DI 10.1029/98WR02611 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 145VV UT WOS:000077393000029 ER PT J AU Keating, EH Bahr, JM AF Keating, EH Bahr, JM TI Reactive transport modeling of redox geochemistry: Approaches to chemical disequilibrium and reaction rate estimation at a site in northern Wisconsin SO WATER RESOURCES RESEARCH LA English DT Article ID SANDY SILICATE AQUIFER; SIMULATING TRANSPORT; ORGANIC-MATTER; GROUNDWATER; EVOLUTION; SEDIMENTS; BIODEGRADATION; REDUCTION; CHEMISTRY; SYSTEM AB The purpose of this study is to investigate the hydrology and redox geochemistry of shallow groundwater discharging to a stream in northern Wisconsin. In this organic-rich aquifer, we observe both oxygen reducing zones and iron reducing zones whose boundaries are roughly constant over time. To investigate the apparent steady state between solute fluxes and redox reaction rates, we develop a reactive transport model of carbon oxidation. We use a "quasi-kinetic," "partial-equilibrium" approach to modeling redox reactions, a hybrid approach between traditional equilibrium approaches and fully kinetic approaches that require large computer resources. Our model suggests that observed trends in redox sensitive elements can only be explained by oxidation rates that are both dependent on the predominant electron acceptor and are spatially variable, Our coupled models provide field-based estimates of redox kinetics, which are otherwise difficult to obtain in hydrologically complex systems. C1 Univ Calif Los Alamos Natl Lab, Geoanal Grp, Los Alamos, NM 87545 USA. Univ Wisconsin, Dept Geol & Geophys, Madison, WI 53706 USA. RP Keating, EH (reprint author), Univ Calif Los Alamos Natl Lab, Geoanal Grp, POB 1663, Los Alamos, NM 87545 USA. RI Keating, Elizabeth/B-4678-2011 NR 40 TC 22 Z9 22 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD DEC PY 1998 VL 34 IS 12 BP 3573 EP 3584 DI 10.1029/98WR02610 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA 145VV UT WOS:000077393000030 ER PT J AU Miller, MA Verlinde, J Gilbert, CV Lehenbauer, GJ Tongue, JS Clothiaux, EE AF Miller, MA Verlinde, J Gilbert, CV Lehenbauer, GJ Tongue, JS Clothiaux, EE TI Detection of nonprecipitating clouds with the WSR-88D: A theoretical and experimental survey of capabilities and limitations SO WEATHER AND FORECASTING LA English DT Article ID DOPPLER RADAR AB Theoretical calculations and experiments verify that the National Weather Service WSR-88D radars have the sensitivity to detect nonprecipitating clouds, but shaw that significant obstacles impair the generality of this cloud sensing technique. Bragg scatter from refractive index inhomogeneities can be of the same magnitude as cloud echoes under many conditions, whereupon interpretation of WSR-88D echoes can be either complicated or impossible. Moreover, problems with echoes from ground clutter and from insects, birds, and other floating debris hinder WSR-88D cloud detection capabilities, particularly at low elevation angles. To illustrate these problems WSR-88D reflectivities collected using volume coverage pattern (VCP) 21 from the months of March and October 1996 were compared with collocated reflectivities obtained from a zenith-pointing 94-GHz cloud radar located in central Pennsylvania. Coincident echo detection occurred 82% and 39% of the time, while the WSR-88D had significant detections 7% and 44% more of the time, during the March and October periods, respectively. For the coincident detections, there were a number of discrepancies in the reflectivity values that were a function of season, height, and time of day. In a separate analysis the WSR-88D located in Upton, Long Island, New York, was used to validate the theoretical minimum detectable signal of the radar in VCP 31 and show that ground clutter contamination may remain despite the use of clutter suppression techniques. In summary, the results of this study suggest that WSR-88D reflectivity data may contain useful information about cloud structure when cloud droplets are the dominant scatterers. To determine if they are dominant requires information about the turbulent structure of the measurement volume and a method to discriminate undesirable targets such as ground clutter, insects, and birds. These requirements suggest that remotely sensing nonprecipitating and lightly precipitating clouds with the WSR-88D would be a difficult process to automate. Extrapolation of the results of this study imply that the best time to remotely sense low clouds with the WSR-88D may be winter nights and mornings when 1) clouds and wind prevent the development of a strong surface-based inversion that can produce beam ducting that enhances ground clutter, 2) insects and birds are not present, and 3) moisture gradients in the lower troposphere are relatively weak, which may reduce the likelihood that Bragg scatter from turbulent eddies would dominate Rayleigh scatter from cloud droplets. C1 Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Penn State Univ, Dept Meteorol, University Pk, PA 16802 USA. Univ Kansas, Dept Phys & Astron, Lawrence, KS 66045 USA. Natl Weather Serv, Weather Forecast Off, Upton, NY USA. RP Miller, MA (reprint author), Brookhaven Natl Lab, Dept Appl Sci, POB 5000, Upton, NY 11973 USA. NR 18 TC 13 Z9 13 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0882-8156 J9 WEATHER FORECAST JI Weather Forecast. PD DEC PY 1998 VL 13 IS 4 BP 1046 EP 1062 DI 10.1175/1520-0434(1998)013<1046:DONCWT>2.0.CO;2 PG 17 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 150KC UT WOS:000077663200010 ER PT J AU Anders, A AF Anders, A TI Interaction of vacuum-arc-generated macroparticles with a liquid surface SO APPLIED PHYSICS LETTERS LA English DT Article ID DEPOSITION AB The concept of trapping vacuum-arc-generated macroparticles by a liquid is introduced. Experiments have been performed using a pulsed vacuum arc plasma source operating with a carbon cathode. Vacuum pump oil was used as the trapping liquid in vacuum. It was experimentally shown that trapping did not work as anticipated: a substantial number of particles experienced elastic reflection from the liquid surface. With simplified energy and momentum balances it is shown that the liquid behaves increasingly like a solid when the approaching particle is fast. A significant portion of its kinetic energy is transformed into deformation energy which can reappear as kinetic energy of the reflected particle. Particle reflection is likely to be additionally supported by a Leidenfrost-type effect: a thin oil vapor layer of relatively high pressure can be formed between the liquid surface and the macroparticle caused by the macroparticle's high temperature. (C) 1998 American Institute of Physics. [S0003-6951(98)03248-3]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 6 TC 5 Z9 5 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 NOV 30 PY 1998 VL 73 IS 22 BP 3199 EP 3201 DI 10.1063/1.122717 PG 3 WC Physics, Applied SC Physics GA 143MR UT WOS:000077259900007 ER PT J AU Sun, J Su, C Meier, M Isied, SS Wishart, JF van Eldik, R AF Sun, J Su, C Meier, M Isied, SS Wishart, JF van Eldik, R TI Mechanistic information from the first volume profile analysis for intramolecular electron-transfer reactions: Tetraammine-ruthenium(ligand) complexes of cytochrome c SO INORGANIC CHEMISTRY LA English DT Article ID PRESSURE PULSE-RADIOLYSIS; AMMINE COMPLEXES; VOLTAMMETRY; DEPENDENCE; RADICALS; KINETICS; EXCHANGE; SERIES; RATES; ACID C1 Univ Erlangen Nurnberg, Inst Inorgan Chem, D-91058 Erlangen, Germany. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Rutgers State Univ, Dept Chem, Piscataway, NJ 08854 USA. RP Wishart, JF (reprint author), Univ Erlangen Nurnberg, Inst Inorgan Chem, D-91058 Erlangen, Germany. RI Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 NR 31 TC 15 Z9 15 U1 0 U2 0 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 NOV 30 PY 1998 VL 37 IS 24 BP 6129 EP 6135 DI 10.1021/ic980999f PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 144TV UT WOS:000077331900001 ER PT J AU Clark, DL Click, DR Grumbine, SK Scott, BL Watkin, JG AF Clark, DL Click, DR Grumbine, SK Scott, BL Watkin, JG TI Mono(pentamethylcyclopentadienyl)titanium and -zirconium complexes supported by chiral diolate ligands. X-ray crystal structures of [(eta-C5Me5)TiCl(mu-eta(1),eta(1)-2-CF3-dpbd)](2) and [HNEt3][(eta-C5Me5)(2)Zr2Cl2(mu-Cl)(mu-eta(1),eta(2)-3,5-Me-2-dpbd)(2)] SO INORGANIC CHEMISTRY LA English DT Article ID CATALYTIC ASYMMETRIC-SYNTHESIS; MUKAIYAMA ALDOL REACTION; CARBONYL-ENE REACTIONS; DIELS-ALDER REACTIONS; ENANTIOSELECTIVE ADDITION; MOLECULAR-STRUCTURE; ANSA-METALLOCENE; TITANIUM; EPOXIDATION; REDUCTION AB Reaction of optically pure (S,S)-butadiene diepoxide (1) with 2 equiv of Grignard reagent ArMgBr (Ar = 2-CF3C6H4 or 3,5-Me2C6H3) in the presence of copper(I) iodide produces the chiral substituted diphenylbutanediols (dpbd) (2S,3S)-ArCH2CH(OH)CH(OH)CH2Ar (Ar = 2-CF3C6H4 (2), abbreviated 2-CF3-dpbdH(2); Ar = 3,5-Me2C6H3 (3), abbreviated 3,5-Me-2-dpbdH(2)). The mono(pentamethylcyclopentadienyl) halide complex (eta-C5Me5)TiCl3 reacts with 1 equiv of diol 2 in the presence of triethylamine to produce the dimeric species [(eta-C5Me5)TiCl(mu-eta(1),eta(1)- 2-CF3-dpbd)](2) (4). An analogous reaction employing the zirconium halide (eta-C5Me5)ZrCl3 and the diol 3 leads to isolation of the salt complex [HNEt3] [(eta-C5Me5)(2)Zr2Cl2(mu-Cl)(mu-eta(1),eta(2)-3,5-Me-2-dpbd)(2)] (5). Compounds 4 and 5 have been subjected to single-crystal X-ray diffraction studies. The solid-state structure of 4 consists of two titanium metal centers, each bearing a pentamethylcyclopentadienyl ligand and a terminal chloride Ligand, bridged by two diolate ligands such that a central 10-membered ring is formed. The terminal Ti-CI bond length is 2.306(2) Angstrom, and the Ti-O distances range from 1.783(4) to 1.830(5) Angstrom. The two bridging diolate ligands adopt widely differing conformations such that one diolate ligand possesses Ti-O-C angles of 172.3(4) and 172.4(4)degrees while the other displays acute Ti-O-C angles of 125.2(4)degrees. The molecular geometry of the anion in 5 is comprised of two (eta-C5Me5)ZrCl moieties bridged by a single mu(2)-Cl ligand and two diolate ligands. One oxygen atom within each diolate ligand acts as a mu(2) bridge between the zirconium metal centers whereas the other is bound in a terminal fashion to one metal center, thus forming a central Zr2O2 four-membered ring and two ZrO2C2 five-membered rings. Bridging Zr-Cl distances are 2.606(4) and 2.737(3) Angstrom, and terminal Zr-Cl bond lengths are 2.499(4) and 2.584(4) Angstrom. Terminal Zr-O distances are 1.989(9) and 1.972(9) Angstrom, and bridging Zr-O distances range from 2.125(9) to 2.222(8) Angstrom. Crystal data for 4 (at -90 degrees C): monoclinic space group P2(1), a = 12.399(1), b = 22.229(2), c = 13.275(1) Angstrom, beta = 111.208(6)degrees, V = 3411 Angstrom(3), Z = 2, D-calc = 1.338 g cm(-3). Crystal data for 5 (at -90 degrees C): orthorhombic space group P2(1)2(1)2(1), a = 13.615(2), b = 13.623(2), c = 36.042(5) Angstrom, V = 6685 Angstrom(3), Z = 3, D-calc = 1.246 g cm(-3). C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Watkin, JG (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663, Los Alamos, NM 87545 USA. RI Clark, David/A-9729-2011; Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 76 TC 4 Z9 4 U1 0 U2 0 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 NOV 30 PY 1998 VL 37 IS 24 BP 6237 EP 6243 DI 10.1021/ic980645o PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 144TV UT WOS:000077331900016 ER PT J AU Lugmair, CG Tilley, TD AF Lugmair, CG Tilley, TD TI Layered zincophosphate materials prepared from a molecular zinc di(tert-butyl)phosphate complex in organic solvents SO INORGANIC CHEMISTRY LA English DT Article ID HIGH-SURFACE-AREA; NEUTRAL TEMPLATING ROUTE; MESOPOROUS SILICA; PHYSICAL-PROPERTIES; SIEVES; PHASES; OXIDE; PHOSPHATE; PHOSPHONATES; INTERCALATION AB Layered zincophosphate materials were prepared from the molecular precursor Zn-4(mu(4)-O)[O2P((OBu)-Bu-t)(2)](6) (1) via thermolysis (180-215 degrees C) in anhydrous organic solvents in the presence of long-chain primary amines. Through variation of the amine concentration, two series of materials were obtained with the stoichiometries Zn-2(HPO4)(3)(H-3- NCnH2n+1)(2) and Zn-2(HPO4)(3)(H3NCnH2n+1)(2)(H2NCnH2n+1) (n = 8-16) These materials possess an unusual Zn/P ratio of 2:3 which is uncommon for layered zincophosphate materials prepared in aqueous media. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 41 TC 20 Z9 20 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD NOV 30 PY 1998 VL 37 IS 24 BP 6304 EP 6307 DI 10.1021/ic980501+ PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 144TV UT WOS:000077331900025 ER PT J AU Abramov, YA Brammer, L Klooster, WT Bullock, RM AF Abramov, YA Brammer, L Klooster, WT Bullock, RM TI Experimental charge density and neutron structural study of cis-HMn(CO)(4)PPh3: Comprehensive analysis of chemical bonding and evidence for a C-H center dot center dot center dot H-Mn hydrogen bond SO INORGANIC CHEMISTRY LA English DT Review ID ORGANOMETALLIC REACTION-MECHANISMS; ELECTRON POPULATION ANALYSIS; TRANSITION-METAL COMPLEXES; ACCURATE DIFFRACTION DATA; X-RAY-DIFFRACTION; TOPOLOGICAL ANALYSIS; CRYSTAL-STRUCTURE; SUBSTITUTION-REACTIONS; POLYHYDRIDE COMPLEXES; ROBUST ALGORITHM AB The structure and bonding in cis-HMn(CO)(4)PPh3 have been studied by low-temperature neutron and high-resolution X-ray diffraction, the latter study using a charge-coupled device (CCD) area detector. A charge density analysis, including the deformation density, a full topological analysis of p, and selected topological analysis of -del(2)p, has been conducted, cis-HMn(CO)(4)PPh3 adopts an approximately octahedral geometry, the largest deviation being the C(1)-Mn-C(3) angle of 160.0(1)degrees. The hydride ligand (Mn-H(1), 1.573(2) Angstrom) is nucleophilic in nature (i.e., hydridic, with an effective atomic charge of -0.4e) and makes a short contact (2.101(3) Angstrom) with an electrophilic (+0.3e) ortho phenyl hydrogen. The electrostatic component of the Hdelta+... Hdelta- interaction energy is calculated to be 5.7 kcal/mol from the experimental data. This electrostatic evidence coupled with the geometry (C-H ... H 129.0(2)degrees and H ... H-Mn 126.5(1)degrees) and the identification of an H ... H bond path in the charge density distribution strongly supports the characterization of this interaction as an intramolecular C-H ... H-Mn hydrogen bond. Both the deformation density and the topological study clearly illustrate the sigma-donor nature of both the H-Mn and Ph3P-Mn interactions and the sigma-donor/pi-acceptor nature of the manganese-carbonyl bonds. The topological study further confirms the decrease in C-O bond order upon coordination to the metal and demonstrates for the first time by this method that the metal-ligand bonds, although showing characteristics of a closed-shell interaction, do have a significant dative covalent component to the bond. The latter is reinforced by a study of the derived Mn d-orbital populations, in which populations of the d(z2) and d(x2-y2) orbitals are significantly higher than would be predicted by a simple crystal field theory model of metal-ligand bonding. C1 Univ Missouri, Dept Chem, St Louis, MO 63121 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Brammer, L (reprint author), Univ Missouri, Dept Chem, 8001 Nat Bridge Rd, St Louis, MO 63121 USA. RI Bullock, R. Morris/L-6802-2016 OI Bullock, R. Morris/0000-0001-6306-4851 NR 105 TC 56 Z9 56 U1 1 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD NOV 30 PY 1998 VL 37 IS 24 BP 6317 EP 6328 DI 10.1021/ic9809660 PG 12 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 144TV UT WOS:000077331900027 ER PT J AU Londono, JD Maranas, JK Mondello, M Habenschuss, A Grest, GS Debenedetti, PG Graessley, WW Kumar, SK AF Londono, JD Maranas, JK Mondello, M Habenschuss, A Grest, GS Debenedetti, PG Graessley, WW Kumar, SK TI Chain-packing effects in the thermodynamics of polymers SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article ID SATURATED-HYDROCARBON POLYMERS; MOLECULAR-DYNAMICS; MIXING BEHAVIOR; BLENDS; MELTS; POLYISOBUTYLENE; POLYMETHYLENE; PREDICTIONS; SIMULATIONS C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Princeton Univ, Dept Chem Engn, Princeton, NJ 08540 USA. Exxon Res & Engn Co, Corp Res Sci Labs, Annandale, NJ 08801 USA. RP Kumar, SK (reprint author), Penn State Univ, Dept Mat Sci & Engn, 320 Steidle Bldg, University Pk, PA 16802 USA. NR 29 TC 12 Z9 12 U1 0 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD NOV 30 PY 1998 VL 36 IS 16 BP 3001 EP 3005 DI 10.1002/(SICI)1099-0488(19981130)36:16<3001::AID-POLB14>3.0.CO;2-H PG 5 WC Polymer Science SC Polymer Science GA 136BC UT WOS:000076837000014 ER PT J AU Belyaev, VM Johnson, MB AF Belyaev, VM Johnson, MB TI Twist-two lightcone pion wave function SO MODERN PHYSICS LETTERS A LA English DT Article ID QCD SUM-RULES; FORM-FACTORS; RELATIVISTIC QUARKS; EXCLUSIVE PROCESSES; RESONANCE PHYSICS; FRONT DYNAMICS; DECAYS; MESONS; MODEL AB We present an analysis of the existing constraints for the twist-two lightcone pion wave function. We find that existing information on the pion wave function does not exclude the possibility that the pion wave function attains its asymptotic form. New bounds on the parameters of the pion wave function are presented. C1 Inst Theoret & Expt Phys, Moscow 117259, Russia. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Belyaev, VM (reprint author), Inst Theoret & Expt Phys, B Cheremushkinskaya 25, Moscow 117259, Russia. NR 35 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 912805, SINGAPORE SN 0217-7323 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD NOV 30 PY 1998 VL 13 IS 36 BP 2909 EP 2913 DI 10.1142/S0217732398003089 PG 5 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA 150FK UT WOS:000077653100003 ER PT J AU Gade, A Wiedenhover, I Diefenbach, T Gelberg, A Luig, M Meise, H Pietralla, N Wilhelm, M Otsuka, T von Brentano, P AF Gade, A Wiedenhover, I Diefenbach, T Gelberg, A Luig, M Meise, H Pietralla, N Wilhelm, M Otsuka, T von Brentano, P TI Non-yrast states of Ce-132 populated in beta-decay SO NUCLEAR PHYSICS A LA English DT Article DE Pr-132(beta(+)) [from Sn-117(F-19,4n)]; measured E gamma, I gamma, gamma gamma-coin following beta decay; Ce-132 deduced levels; J, pi, delta; comparison with IBM calculations ID INTERACTING-BOSON MODEL; COLLECTIVE NUCLEAR-STATES; QUADRUPOLE-PHONON EXCITATIONS; MIXED-SYMMETRY; GAMMA-DEFORMATION; O(6) LIMIT; TRANSITIONS; REGION; BA-130; XE AB Non-yrast low spin states of the nucleus Ce-132 were studied by means of gamma-spectroscopy following the beta-decay of the ground and medium spin isomeric states of Pr-132. The activity was produced with the reaction Sn-117(F-19, 4n) Pr-132 at the Cologne FN TANDEM accelerator. The gamma gamma coincidences and singles spectra were measured with the OSIRIS cube spectrometer. The beta-decay of Pr-132 populates states with spins up to 6 (H) over bar and excitation energies up to 4.4 MeV in Ce-132. Besides ground and quasi-gamma bands, an excited band based on the 0(2)(+) state and many other low-lying states were observed. The gamma gamma angular correlations were analyzed to assign spins and parities to the excited states, and to determine the multipolarities of the gamma-transitions, We found dominant E2 transitions in the quasi-gamma band and from the quasi-gamma band to the ground band. The experimental data are compared with calculations using the Interacting Boson Model (IBM). Good agreement is reached in the vicinity of the O(6) limit. O 1998 Elsevier Science B.V. C1 Univ Cologne, Inst Kernphys, D-50937 Cologne, Germany. Univ Tokyo, Dept Phys, Tokyo 113, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. RP Gade, A (reprint author), Univ Cologne, Inst Kernphys, Zulpicher Str 77, D-50937 Cologne, Germany. RI Gade, Alexandra/A-6850-2008; OTSUKA, TAKAHARU/G-5072-2014 OI Gade, Alexandra/0000-0001-8825-0976; NR 45 TC 20 Z9 20 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 NOV 30 PY 1998 VL 643 IS 3 BP 225 EP 242 DI 10.1016/S0375-9474(98)00555-7 PG 18 WC Physics, Nuclear SC Physics GA 144VM UT WOS:000077336000001 ER PT J AU Hochberg, D Molina-Paris, C Perez-Mercader, J Visser, M AF Hochberg, D Molina-Paris, C Perez-Mercader, J Visser, M TI Zeta functions, renormalization group equations, and the effective action SO PHYSICAL REVIEW LETTERS LA English DT Article ID GAUGE-THEORIES; ENERGY AB We demonstrate how to extract all the one-loop renormalization group equations for arbitrary quantum field theories from knowledge of an appropriate Seeley-DeWitt coefficient. By formally solving the renormalization group equations to one loop, we renormalization group improve the classical action and use this to derive the leading logarithms in the one-loop effective action for arbitrary quantum field theories. [S0031-9007(98)07781-3]. C1 Lab Astrofis Espacial & Fis Fundamental, Madrid 28080, Spain. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Washington Univ, Dept Phys, St Louis, MO 63130 USA. RP Hochberg, D (reprint author), Lab Astrofis Espacial & Fis Fundamental, Apartado 50727, Madrid 28080, Spain. OI Visser, Matt/0000-0003-1088-6485 NR 22 TC 6 Z9 6 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 30 PY 1998 VL 81 IS 22 BP 4802 EP 4805 DI 10.1103/PhysRevLett.81.4802 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900005 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, 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, O Field, 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, R 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 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 Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martignon, G 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 Musy, M 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, 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, O Field, 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, R 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 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 Lys, J Maeshima, K Maksimovic, P Mangano, M Mariotti, M Marriner, JP Martignon, G 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 Musy, M 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 second generation leptoquarks in the Dimuon plus Dijet channel of p(p)over-bar collisions at root s = 1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID (P)OVER-BAR-P COLLISIONS; PARTON DISTRIBUTIONS; SCALAR LEPTOQUARKS; ROOT-S=1.8 TEV; PAIR PRODUCTION; DECAYS; DETECTOR; LEP AB We report on a search for second generation leptoquarks (Phi(2)) using a data sample corresponding to an integrated luminosity of 110 pb(-1) collected at the Collider Detector at Fermilab. We present upper limits on the production cross section as a function of Phi(2) mass, assuming that the leptoquarks are produced in pairs and decay into a muon and a quark with branching ratio beta. Using a next-to-leading order quantum chromodynamics calculation, we extract a lower mass limit of M(Phi 2) > 202(160) GeV/c(2) at 95% confidence level for scalar leptoquarks with beta = 1(0.5). [S0031-4007(98)07705-9]. C1 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. Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Florida, Gainesville, FL 32611 USA. Ist Nazl Fis Nucl, Lab Nazl Frascati, I-00044 Frascati, Italy. Univ Geneva, CH-1211 Geneva 4, Switzerland. Harvard Univ, Cambridge, MA 02138 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Univ Illinois, Urbana, IL 61801 USA. 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. KEK, Natl Lab High Energy Phys, Tsukuba, Ibaraki 305, Japan. 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 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, Garden City, NY 11530 USA. Texas A&M Univ, College Stn, TX 77843 USA. Texas Tech Univ, Lubbock, TX 79409 USA. Univ Trieste, Ist Nazl Fis Nucl, Udine, Italy. Univ Tsukuba, Tokyo, 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), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Lancaster, Mark/C-1693-2008; Vucinic, Dejan/C-2406-2008; Nomerotski, Andrei/A-5169-2010; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Paulini, Manfred/N-7794-2014; Introzzi, Gianluca/K-2497-2015; vilar, rocio/D-7454-2014 OI Azzi, Patrizia/0000-0002-3129-828X; Punzi, Giovanni/0000-0002-8346-9052; Chiarelli, Giorgio/0000-0001-9851-4816; Warburton, Andreas/0000-0002-2298-7315; Paulini, Manfred/0000-0002-6714-5787; Introzzi, Gianluca/0000-0002-1314-2580; NR 33 TC 29 Z9 30 U1 0 U2 1 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 NOV 30 PY 1998 VL 81 IS 22 BP 4806 EP 4811 DI 10.1103/PhysRevLett.81.4806 PG 6 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900006 ER PT J AU Bernard, C DeGrand, T DeTar, C Gottlieb, S Heller, UM Hetrick, JE Ishizuka, N McNeile, C AF Bernard, C DeGrand, T DeTar, C Gottlieb, S Heller, UM Hetrick, JE Ishizuka, N McNeile, C TI Lattice determination of heavy-light decay constants SO PHYSICAL REVIEW LETTERS LA English DT Article ID PERTURBATION-THEORY AB We report on the MILC Collaboration's calculation of f(B), f(Bs), f(D), f(Ds), and their ratios. Our central values come from the quenched approximation, but the quenching error is estimated from N-F = 2 dynamical staggered lattices. We use Wilson light valence quarks and Wilson and static heavy quarks. for example, f(B) = 157 +/- 11(-9-0)(+25+23) MeV, f(Bs)/f(B) = 1.11 +/- 0.02(-0.03)(+0.04) +/- 0.03, f(D), = 210 +/- 9(-9-1)(+25+17) MeV, and f(B)/f(Ds) = 0.75 +/- 0.03(-0.02-0.00),(+0.04+0.08) where the errors are statistical, systematic (within the quenched approximation), and systematic (of quenching), respectively. [S0031-9007(98)07819-3]. C1 Washington Univ, St Louis, MO 63130 USA. Univ Colorado, Boulder, CO 80309 USA. Univ Utah, Salt Lake City, UT 84112 USA. Indiana Univ, Bloomington, IN 47405 USA. Florida State Univ, Supercomp Computat Res Inst, Tallahassee, FL 32306 USA. Univ Pacific, Stockton, CA 95211 USA. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Univ Calif Santa Barbara, Santa Barbara, CA 93106 USA. Univ Arizona, Tucson, AZ 85721 USA. RIKEN, Brookhaven Natl Lab, Res Ctr, Upton, NY 11973 USA. RP Washington Univ, St Louis, MO 63130 USA. OI Hetrick, James/0000-0002-0740-2251; Heller, Urs M./0000-0002-2780-5584; Wingate, Matthew/0000-0001-6568-988X NR 20 TC 59 Z9 59 U1 0 U2 0 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 NOV 30 PY 1998 VL 81 IS 22 BP 4812 EP 4815 DI 10.1103/PhysRevLett.81.4812 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900007 ER PT J AU Hogan, MJ Pellegrini, C Rosenzweig, J Anderson, S Frigola, P Tremaine, A Fortgang, C Nguyen, DC Sheffield, RL Kinross-Wright, J Varfolomeev, A Varfolomeev, AA Tolmachev, S Carr, R AF Hogan, MJ Pellegrini, C Rosenzweig, J Anderson, S Frigola, P Tremaine, A Fortgang, C Nguyen, DC Sheffield, RL Kinross-Wright, J Varfolomeev, A Varfolomeev, AA Tolmachev, S Carr, R TI Measurements of gain larger than 10(5) at 12 mu m in a self-amplified spontaneous-emission free-electron laser SO PHYSICAL REVIEW LETTERS LA English DT Article ID REGIME AB We report measurements of very large output intensities corresponding to a gain larger than 10(5) for a single pass free-electron laser operating in the self-amplified spontaneous emission (SASE) mode at 12 mu m. We also report the observation and analysis of intensity fluctuations of the SASE radiation intensity in the high-gain regime. The results are compared with theoretical predictions and simulations. [S0031-9007(98)07403-1]. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Kurchatov Inst, RRC, Moscow, Russia. Stanford Synchrotron Radiat Lab, Palo Alto, CA 94304 USA. RP Hogan, MJ (reprint author), Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. NR 26 TC 94 Z9 96 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 NOV 30 PY 1998 VL 81 IS 22 BP 4867 EP 4870 DI 10.1103/PhysRevLett.81.4867 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900021 ER PT J AU Deeney, C Douglas, MR Spielman, RB Nash, TJ Peterson, DL L'Eplattenier, P Chandler, GA Seamen, JF Struve, KW AF Deeney, C Douglas, MR Spielman, RB Nash, TJ Peterson, DL L'Eplattenier, P Chandler, GA Seamen, JF Struve, KW TI Enhancement of X-ray power from a Z pinch using nested-wire arrays SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; INERTIAL CONFINEMENT FUSION; SUPPRESSION; SATURN; LOADS AB Nested-wire arrays on the 20-MA Z-pinch accelerator have produced x-ray powers up to 280 +/- 40 TW (a 40% increase over a single array) and an x-ray pulse width of 4 ns. The short x-ray pulse widths are associated with the formation of tight (l-mm-diameter), uniform pinches at stagnation. Two-dimensional radiation magnetohydrodynamic calculations suggest that the inner array mitigates the growth of implosion instabilities thereby leading to smaller diameter pinches that radiate at higher power than single-wire arrays. [S0031-9007(98)07768-0]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Deeney, C (reprint author), Sandia Natl Labs, MS-1194,POB 5800, Albuquerque, NM 87185 USA. NR 17 TC 303 Z9 341 U1 1 U2 11 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 30 PY 1998 VL 81 IS 22 BP 4883 EP 4886 DI 10.1103/PhysRevLett.81.4883 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900025 ER PT J AU Liang, EP Wilks, SC Tabak, M AF Liang, EP Wilks, SC Tabak, M TI Pair production by ultraintense lasers SO PHYSICAL REVIEW LETTERS LA English DT Article ID RELATIVISTIC THERMAL PLASMAS AB We consider the production of electron-positron pairs by the interaction of relativistic superthermal electrons, generated by ultraintense laser pulses, with high-Z material. We discuss the laser and target parameters required in order to optimize the pair-production rate. We explore the regime when the pairs, if sufficiently confined, can start to exponentiate in number and explore the feasibility of achieving a pair density approaching 10(21) cm(-3), 1/50 th that of solid-ion density. [S0031-9007(98)07766-7]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Liang, EP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 10 TC 290 Z9 295 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 30 PY 1998 VL 81 IS 22 BP 4887 EP 4890 DI 10.1103/PhysRevLett.81.4887 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900026 ER PT J AU Chen, XD Gibson, JM AF Chen, XD Gibson, JM TI Experimental evidence of a gaussian roughness at Si(111)/SiO2 interfaces SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-SCATTERING; SCANNING-TUNNELING-MICROSCOPY; ATOMIC-FORCE MICROSCOPY; DYNAMIC OBSERVATIONS; DIFFUSE-SCATTERING; SI-SIO2 INTERFACE; SURFACE-ROUGHNESS; ION-SCATTERING; SILICON; OXIDATION AB With a plan-view transmission electron microscope technique to unambiguously image the "physical" interface position between Si and furnace grown SiO2 layers, we first show experimental evidence that the height-height autocorrelation function is a Gaussian function at Si(lll)/SiO2 interfaces. With a simple kinetic model, we have found that this Gaussian autocorrelation function is a natural consequence of step motion during silicon oxidation. This result puts interfacial roughness measurements on a firmer foundation in the future. [S0031-9007(98)07785-0]. C1 Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Chen, XD (reprint author), Argonne Natl Lab, Div Sci Mat, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Gibson, Murray/E-5855-2013 OI Gibson, Murray/0000-0002-0807-6224 NR 35 TC 8 Z9 8 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 30 PY 1998 VL 81 IS 22 BP 4919 EP 4922 DI 10.1103/PhysRevLett.81.4919 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900034 ER PT J AU Fishman, RS AF Fishman, RS TI Helical and incommensurate spin-density waves in Fe/Cr multilayers with interfacial steps SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC-STRUCTURE; CHROMIUM-ALLOYS; SUPERLATTICES; CR; ANTIFERROMAGNETISM; TRANSITION AB Although absent in bulk transition metals, a noncollinear, helical (H) spin-density wave (SDW) is stabilized by steps at the interfaces in Fe/Cr multilayers. Using the random-phase approximation, we evaluate the phase boundary between the H SDW and the collinear, incommensurate (I) SDW found in bulk Cr. In agreement with neutron-scattering results, the I-to-H transition temperature T-IH is always lower than the bulk Neel temperature T-N and the nodes of the I SDW lie near the Fe-Cr interfaces. While a H SDW with a single +/-pi/2 twist has lower free energy than a I SDW above T-N, H SDW's with larger twists are stable between T-IH and T-N. [S0031-9007(98)07739-4]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 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 22 TC 22 Z9 22 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 30 PY 1998 VL 81 IS 22 BP 4979 EP 4982 DI 10.1103/PhysRevLett.81.4979 PG 4 WC Physics, Multidisciplinary SC Physics GA 142WT UT WOS:000077223900049 ER PT J AU Wigley, TML Smith, RL Santer, BD AF Wigley, TML Smith, RL Santer, BD TI Anthropogenic influence on the autocorrelation structure of hemispheric-mean temperatures SO SCIENCE LA English DT Article ID CLIMATE-CHANGE; ATMOSPHERE; MODEL; VARIABILITY; TREND AB It is shown that Lagged correlations for and cross-correlations between observed hemispheric-mean temperature data differ markedly from those for unforced (control-run) climate model simulations. The differences can be explained adequately by assuming that the observed data contain a significant externally forced component involving both natural (solar) and anthropogenic influences and that the global climate sensitivity is in the commonly accepted range. Solar forcing alone cannot reconcile the differences in autocorrelation structure between observations and model control-run data. C1 Natl Ctr Atmospher Res, Boulder, CO 80307 USA. Univ N Carolina, Dept Stat, Chapel Hill, NC 27599 USA. Univ Calif Lawrence Livermore Natl Lab, PCMDI, Livermore, CA 94550 USA. RP Wigley, TML (reprint author), Natl Ctr Atmospher Res, Pob 3000, Boulder, CO 80307 USA. EM wigley@ucar.edu RI Wigley, Tom/B-4705-2008; Santer, Benjamin/F-9781-2011 NR 29 TC 61 Z9 61 U1 0 U2 8 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 NOV 27 PY 1998 VL 282 IS 5394 BP 1676 EP 1679 DI 10.1126/science.282.5394.1676 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 143GJ UT WOS:000077246600037 ER PT J AU Jirsak, T Rodriguez, JA Chaturvedi, S Hrbek, J AF Jirsak, T Rodriguez, JA Chaturvedi, S Hrbek, J TI Chemistry of SO2 on Ru(001): formation of SO3 and SO4 SO SURFACE SCIENCE LA English DT Review DE catalysis; chemisorption; low index single crystal surfaces; ruthenium; semi-empirical models and model calculations; sulfur dioxide; synchrotron radiation photoelectron spectroscopy ID FINE-STRUCTURE SPECTROSCOPY; TRANSITION-METAL SURFACES; SULFUR-DIOXIDE ADSORPTION; ENERGY-LOSS SPECTROSCOPY; PHOTOELECTRON-SPECTROSCOPY; INTERMEDIATE NEGLECT; ELECTRONIC-PROPERTIES; DESORPTION-KINETICS; BIMETALLIC SURFACES; COVERED RU(001) AB The interaction of SO2 with Ru(001) at temperatures of 300 and 100 K has been studied using synchrotron-based high-resolution photoemission, INDO/S self-consistent field calculations, and a thermochemical analysis based on the band order conservation Morse potential (BOC-MP) formalism. At 300 K and small exposures of SO,, sulfur dioxide completely decomposes (SO2 --> S-a + 2O(a)), leaving atomic oxygen and two kinds of sulfur species on the Ru surface (S and S-n + O). Several coordination modes for adsorbed SO2 (eta(1)-S a-top, eta(2)-S bridge, eta(2)-O,O bridge, eta(2)-S,O bridge) were examined using INDO/S and the BOC-MP formalism. It was found that adsorption geometries in which the molecule is dicoordinated via O, O or S,O are the most probable precursors for dissociation. For large exposures of SO2 at 300 K, SO3 and SO4 species appear on the Ru(001) surface, thus confirming the theoretical predictions derived from the BOC-MP method which indicate that formation of SO3 and SO4 can take place only when the number of empty adsorption sites is limited. This prediction was also proved during the adsorption of SO2 on an O/Ru(001) surface with theta(O) = 0.25 ML, producing similar types of species as at saturation of SO2 on Ru (S-n + O, SO4 and S). Experiments performed at a surface temperature of 100 K showed a very rich surface chemistry. Five different surface species were observed after SO2 dosing: atomic S, S-n + O, SO2, SO3 and SO4. Annealing to 260 K leaves mainly atomic S and SO4 on the surface and the latter is completely decomposed by 350 K. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodriguez@ebnl.gov RI Hrbek, Jan/I-1020-2013 NR 107 TC 21 Z9 21 U1 0 U2 4 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 NOV 27 PY 1998 VL 418 IS 1 BP 8 EP 21 DI 10.1016/S0039-6028(98)00652-9 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 148VM UT WOS:000077554300010 ER PT J AU Zhuang, GR Chen, YF Ross, PN AF Zhuang, GR Chen, YF Ross, PN TI The reaction of lithium with carbon dioxide studied by photoelectron spectroscopy SO SURFACE SCIENCE LA English DT Article DE carbonate; carbon dioxide; carbon monoxide; lithium; peroxide; photoelectron spectroscopy; superoxide; surface chemical reaction ID PROPYLENE CARBONATE; CO2 ADDITION; LI; ELECTRODES; SURFACES; ALKALI; XPS; TETRAHYDROFURAN; ACTIVATION; ADSORPTION AB The interaction of CO2 with clean Li at 120-320 K was studied using photoelectron spectroscopy. To assist in the interpretation of the spectra, the C 1s and O 1s core-level binding energies of various Li cluster compounds were calculated using an ab initio SCF method. To further understand the reaction pathway, we also studied the reaction of CO2 with an O-2 pre-dosed Li surface, and the adsorption of CO on clean Li. The principal reactions occurring between CO2 (1-30 L) and Li at 120-320 K are: CO(2)double right arrow[CO2](eds), 2[CO2](ads)double right arrow CO32- COads, probably via an oxalate, [C2O4](ads), intermediate, and: CO(ads)double right arrow C+ O2-, CO2 + O(2-)double right arrow CO32-. The relative rates of these reactions are temperature dependent. At 120 K, the main products are CO32-, COads, and [CO2](ads), whereas at 320 K the main products are O2- and elemental carbon with a relatively small amount of CO32-. The reactions are similar to those on the other alkali metals, Na, K and Cs, with the important exception being the much stronger interaction with CO, leading to dissociation and carbon formation. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. RP Ross, PN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. EM pnross@lbl.gov NR 31 TC 13 Z9 13 U1 4 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 27 PY 1998 VL 418 IS 1 BP 139 EP 149 DI 10.1016/S0039-6028(98)00710-9 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 148VM UT WOS:000077554300023 ER PT J AU McCoy, JM Korte, U Maksym, PA AF McCoy, JM Korte, U Maksym, PA TI Determination of the atomic geometry of the GaAs(001)2x4 surface by dynamical RHEED intensity analysis: the beta 2(2x4) model SO SURFACE SCIENCE LA English DT Article DE electron-solid interactions, scattering and diffraction; reflection high-energy electron diffraction (RHEED); surface structure, morphology, roughness and topography; low index single crystal surfaces; gallium arsenide; semiconducting surfaces ID SCANNING-TUNNELING-MICROSCOPY; STRUCTURAL TRANSITION; RECONSTRUCTIONS; GAAS(100)-(2X4); DIFFRACTION; PT(110); ENERGETICS; 2X4 AB Using dynamical reflection high-energy electron diffraction (RHEED) computations, experimental RHEED rocking curves from the MBE-grown As-rich GaAs(001)2 x 4 surface have been analysed to provide estimates of the surface structural parameters. Ab initio total-energy computations suggest that surfaces grown in such As-rich conditions are likely to exist in the so-called beta 2(2 x 4) phase. Therefore, it is assumed that the most appropriate GaAs(001)2 x 4 surface model with which to analyse the experimental data is that of the beta 2(2 x 4) phase. This phase has two As dimers in the surface layer and a third As dimer in the third layer. The experimental rocking curves analysed were measured in the primary beam azimuth, permitting estimates of those beta 2(2 x 4) phase surface structural parameters in the plane perpendicular to the primary beam azimuth. The best experiment-theory fit was obtained using a standard non-linear optimisation scheme (the Marquardt algorithm). We find that by using the beta 2(2 x 4) surface model we are able to get a better fit to the experimental data than in earlier work in which the data were analysed using the beta(2 x 4) surface model. This supports the assumption that the beta 2(2 x 4) surface model is the most appropriate to describe the surface in the As-rich MBE growth conditions used to produce the sample surface upon which the RHEED experiments were performed. Our best-fit beta 2(2 x 4) surface structure is predominantly in agreement with that obtained from a surface X-ray diffraction study and from ab initio total-energy calculations. As in these other studies, our best-fit structure shows a large in-plane relaxation of the second layer threefold coordinated Ga atoms and an outward perpendicular displacement of the first layer As dimers. The good agreement in most details between all of these independent structure determinations suggests that we now have a largely consistent picture of the structure of the GaAs(001)beta 2(2 x 4) surface. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Leicester, Dept Phys & Astron, Leicester LE1 7RH, Leics, England. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA USA. Univ Osnabruck, Fachbereich Phys, D-49069 Osnabruck, Germany. RP Maksym, PA (reprint author), Univ Leicester, Dept Phys & Astron, Univ Rd, Leicester LE1 7RH, Leics, England. NR 35 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 27 PY 1998 VL 418 IS 1 BP 273 EP 280 DI 10.1016/S0039-6028(98)00723-7 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 148VM UT WOS:000077554300033 ER PT J AU Tompson, AFB Falgout, RD Smith, SG Bosl, WJ Ashby, SF AF Tompson, AFB Falgout, RD Smith, SG Bosl, WJ Ashby, SF TI Analysis of subsurface contaminant migration and remediation using high performance computing SO ADVANCES IN WATER RESOURCES LA English DT Article DE contaminant transport; porous media; remediation; heterogeneity; high performance computation ID HETEROGENEOUS POROUS-MEDIA; NUMERICAL-SIMULATION; GROUNDWATER-FLOW; TRANSPORT; AQUIFERS; DEPOSITS AB Highly resolved simulations of groundwater flow, chemical migration and contaminant recovery processes are used to test the applicability of stochastic models of flow and transport in a typical field setting. A simulation domain encompassing a portion of the upper saturated aquifer materials beneath the Lawrence Livermore National Laboratory was developed to hierarchically represent known hydrostratigraphic units and more detailed stochastic representations of geologic heterogeneity within them. Within each unit, Gaussian random field models were used to represent hydraulic conductivity variation, as parameterized from well test data and geologic interpretation of spatial variability. Groundwater flow, transport and remedial extraction of two hypothetical contaminants were made in six different statistical realizations of the system. The effective flow and transport behavior observed in the simulations compared reasonably with the predictions of stochastic theories based upon the Gaussian models, even though more exacting comparisons were prevented by inherent nonidealities of the geologic model and how system. More importantly, however, biases and limitations in the hydraulic data appear to have reduced the applicability of the Gaussian representations and clouded the utility of the simulations and effective behavior based upon them. This suggests a need for better and unbiased methods for delineating the spatial distribution and structure of geologic materials and hydraulic properties in field systems. High performance computing can be of critical importance in these endeavors, especially with respect to resolving transport processes within highly variable media. (C) 1998 Elsevier Science Limited. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div, Livermore, CA 94550 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Computat, Livermore, CA 94550 USA. RP Tompson, AFB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Geosci & Environm Technol Div, Livermore, CA 94550 USA. NR 30 TC 27 Z9 27 U1 0 U2 3 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD NOV 26 PY 1998 VL 22 IS 3 BP 203 EP 221 DI 10.1016/S0309-1708(98)00013-X PG 19 WC Water Resources SC Water Resources GA 146XP UT WOS:000077458800002 ER PT J AU Scheibe, T Yabusaki, S AF Scheibe, T Yabusaki, S TI Scaling of flow and transport behavior in heterogeneous groundwater systems SO ADVANCES IN WATER RESOURCES LA English DT Article DE transport behavior; heterogeneous groundwater systems ID EFFECTIVE HYDRAULIC CONDUCTIVITY; STOCHASTIC-CONVECTIVE TRANSPORT; NUMERICAL SPECTRAL APPROACH; POROUS-MEDIA; STEADY-STATE; DIMENSIONAL SIMULATIONS; SPATIAL VARIABILITY; BOUNDED DOMAIN; CORE-SCALE; PERMEABILITY AB Three-dimensional numerical simulations using a detailed synthetic hydraulic conductivity field developed from geological considerations provide insight into the scaling of subsurface flow and transport processes. Flow and advective transport in the highly resolved heterogeneous field were modeled using massively parallel computers, providing a realistic baseline for evaluation of the impacts of parameter scaling. Upscaling of hydraulic conductivity was performed at a variety of scales using a flexible power law averaging technique. A series of tests were performed to determine the effects of varying the scaling exponent on a number of metrics of flow and transport behavior. Flow and transport simulation on high-performance computers and three-dimensional scientific visualization combine to form a powerful tool for gaining insight into the behavior of complex heterogeneous systems. Many quantitative groundwater models utilize upscaled hydraulic conductivity parameters, either implicitly or explicitly. These parameters are designed to reproduce the bulk flow characteristics at the grid or field scale while not requiring detailed quantification of local-scale conductivity variations. An example from applied groundwater modeling is the common practice of calibrating grid-scale model hydraulic conductivity or transmissivity parameters so as to approximate observed hydraulic head and boundary flux values. Such parameterizations, perhaps with a bulk dispersivity imposed, are then sometimes used to predict transport of reactive or nonreactive solutes. However, this work demonstrates that those parameters that lead to the best upscaling for hydraulic conductivity and head do not necessarily correspond to the best upscaling for prediction of a variety of transport behaviors. This result reflects the fact that transport is strongly impacted by the existence and connectedness of extreme-valued hydraulic conductivities, in contrast to bulk flow which depends more strongly on mean values. It provides motivation for continued research into upscaling methods for transport that directly address advection in heterogeneous porous media. An electronic version of this article is available online at http://www.elsevier.nl/locate/advwatres or http://www.elsevier/com/locate/advwatres (see "Special section on Visualization"). The online version contains additional supporting information, graphics, and a 3D animation of simulated particle movement. (C) 1998 Elsevier Science Limited. All rights reserved. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Scheibe, T (reprint author), Pacific NW Natl Lab, POB 999,MSIN K9-36, Richland, WA 99352 USA. RI Scheibe, Timothy/A-8788-2008 OI Scheibe, Timothy/0000-0002-8864-5772 NR 44 TC 50 Z9 56 U1 2 U2 10 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0309-1708 J9 ADV WATER RESOUR JI Adv. Water Resour. PD NOV 26 PY 1998 VL 22 IS 3 BP 223 EP 238 DI 10.1016/S0309-1708(98)00014-1 PG 16 WC Water Resources SC Water Resources GA 146XP UT WOS:000077458800003 ER PT J AU Manaa, MR Fried, LE AF Manaa, MR Fried, LE TI DFT and ab initio study of the unimolecular decomposition of the lowest singlet and triplet states of nitromethane SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THEORY; POTENTIAL-ENERGY SURFACES; LIQUID NITROMETHANE; CONFIGURATION-INTERACTION; ELECTRONIC-STRUCTURE; GAS-PHASE; DYNAMICS; SPECTROSCOPY; FREQUENCIES; GEOMETRIES AB The fully optimized potential, energy curves for the unimolecurar decomposition of the lowest singlet and triplet states of nitromethane through the C-NO2 bond dissociation pathway are calculated using various DFT and high-level ab initio electronic structure methods. We perform gradient corrected density functional theory (DFT) and multiconfiguration self-consistent field (MCSCF) to conclusively demonstrate that the triplet state of nitromethane is bound. The adiabatic curve of this state exhibits a 33 kcal/mol energy barrier as determined at the MCSCF level. DFT methods locate this barrier at a shorter C-N bond distance with 12-16 kcal/mol lower energy than does MCSCF. In addition to MCSCF and DFT, quadratic configuration interactions with single and double substitutions (QCISD) calculations are also performed for the singlet curve. The potential energy profiles of this state predicted by DFT methods based on Becke's 1988 exchange functional differ by as much as 17 kcal/mol from the predictions of MCSCF and QCISD in the vicinity of the equilibrium structure. The computational methods predict bond dissociation energies 5-9 kcal/mol lower than the experimental value. DFT techniques based on Becke's 3-parameter exchange functional show the best overall agreement with the higher level methods. C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94551 USA. RP Manaa, MR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, POB 808,L-282, Livermore, CA 94551 USA. EM manaa1@llnl.gov; lfried@llnl.gov RI Fried, Laurence/L-8714-2014 OI Fried, Laurence/0000-0002-9437-7700 NR 56 TC 46 Z9 49 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 26 PY 1998 VL 102 IS 48 BP 9884 EP 9889 DI 10.1021/jp982003s PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 147BA UT WOS:000077467000030 ER PT J AU Hilton, DR McMurtry, GM Goff, F AF Hilton, DR McMurtry, GM Goff, F TI Large variations in vent fluid CO2/He-3 ratios signal rapid changes in magma chemistry at Loihi seamount, Hawaii SO NATURE LA English DT Article ID HYDROTHERMAL SOLUTIONS; ISOTOPIC VARIATIONS; MANTLE VOLATILES; CARBON-DIOXIDE; VOLCANIC-ROCKS; HELIUM; SOLUBILITY; SYSTEMATICS; XENOLITHS; BASALTS AB Loihi seamount, an active submarine volcano situated about 30 km south of the island of Hawaii, is the youngest manifestation of the hotspot responsible for the Emperor-Hawaiian seamount chain and Hawaiian islands. This seamount has been the focus of numerous studies characterizing the geophysical, geochemical and biological features of an active intraplate volcano(1-14). In July-August 1996, Loihi seamount experienced the most intense period of seismic activity yet recorded for any Hawaiian volcano(1). Within two months of the 'seismic crisis: summit and flank hydrothermal vent fluids were collected using a manned submersible. Here we report data from these samples that indicate large and systematic changes in the CO2/He-3 ratios of the vent fluids compared to pre-seismic-crisis values(2,3). These changes are consistent with an abrupt transition from alkalic to tholeiitic basaltic magma having supplied volatiles to the vents. This rapid change in magma Chemistry has been discernible only through CO2/He-3 monitoring, and suggests that the anticipated evolution of the Hawaiian plume to a phase of shield-building tholeiitic magmatism is highly episodic at Loihi and not yet complete. C1 Scripps Inst Oceanog, Geosci Res Div, Isotope Lab, La Jolla, CA 92093 USA. Univ Hawaii, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Hilton, DR (reprint author), Scripps Inst Oceanog, Geosci Res Div, Isotope Lab, La Jolla, CA 92093 USA. EM drhilton@ucsd.edu RI Hilton, David/B-7611-2008 NR 29 TC 61 Z9 63 U1 1 U2 9 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 26 PY 1998 VL 396 IS 6709 BP 359 EP 362 DI 10.1038/24603 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 142MJ UT WOS:000077204000047 ER PT J AU Carena, M Chankowski, PH Pokorski, S Wagner, CEM AF Carena, M Chankowski, PH Pokorski, S Wagner, CEM TI The Higgs boson mass as a probe of the minimal supersymmetric standard model SO PHYSICS LETTERS B LA English DT Article ID ELECTROWEAK SYMMETRY-BREAKING; INFRARED FIXED-POINT; TOP-QUARK MASS; RENORMALIZATION-GROUP; RADIATIVE-CORRECTIONS; SUPERGRAVITY; UNIFICATION; SPECTRUM; BOUNDS; SECTOR AB Recently, the LEP collaborations have reported a lower bound on a Standard Model-like Higgs boson of order 89 GeV. We discuss the implications of this bound for the minimal supersymmetric extension of the Standard Model (MSSM). In particular, we show that the lower bound on tan beta, which can be obtained from the presently allowed Higgs boson mass value, becomes stronger than the one set by the requirement of perturbative consistency of the theory up to scales of order M-GUT (associated with the infrared fixed-point solution of the top quark Yukawa coupling) in a large fraction of the allowed parameter space. The potentiality of future LEP2 searches to further probe the MSSM parameter space is also discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Warsaw, Inst Theoret Phys, PL-00681 Warsaw, Poland. CERN, Div TH, CH-1211 Geneva, Switzerland. RP Carena, M (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 61 TC 30 Z9 30 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 NOV 26 PY 1998 VL 441 IS 1-4 BP 205 EP 214 DI 10.1016/S0370-2693(98)01163-0 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 150GT UT WOS:000077656600028 ER PT J AU Michel, S Nguyen, K Rosenstein, A Zhang, LX Floyd, S Jacobson, V AF Michel, S Nguyen, K Rosenstein, A Zhang, LX Floyd, S Jacobson, V TI Adaptive web caching: towards a new global caching architecture SO COMPUTER NETWORKS AND ISDN SYSTEMS LA English DT Article DE web caching; self-organizing; multicast AB An adaptive, highly scalable, and robust web caching system is needed to effectively handle the exponential growth and extreme dynamic environment of the World Wide Web. Our work presented last year sketched out the basic design of such a system. This sequel paper reports our progress over the past year. To assist caches making web query forwarding decisions, we sketch out the basic design of a URL routing framework. To assist fast searching within each cache group, we let neighbor caches share content information. Equipped with the URL routing table and neighbor cache contents, a cache in the revised design can now search the local group, and forward all missing queries quickly and efficiently, thus eliminating both the waiting delay and the overhead associated with multicast queries. The paper also presents a proposal for incremental deployment that provides a smooth transition from the currently deployed cache infrastructure to the new design. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Angeles, Dept Comp Sci, Los Angeles, CA 90095 USA. Lawrence Berkeley Natl Labs, Berkeley, CA USA. RP Zhang, LX (reprint author), Univ Calif Los Angeles, Dept Comp Sci, 4531G Boelter Hall, Los Angeles, CA 90095 USA. NR 5 TC 30 Z9 30 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7552 J9 COMPUT NETWORKS ISDN JI Comput. Netw. ISDN Syst. PD NOV 25 PY 1998 VL 30 IS 22-23 BP 2169 EP 2177 DI 10.1016/S0169-7552(98)00246-3 PG 9 WC Computer Science, Information Systems; Engineering, Electrical & Electronic; Telecommunications SC Computer Science; Engineering; Telecommunications GA 146TC UT WOS:000077445900011 ER PT J AU Miranda, PB Pflumio, V Saijo, H Shen, YR AF Miranda, PB Pflumio, V Saijo, H Shen, YR TI Chain-chain interaction between surfactant monolayers and alkanes or alcohols at solid/liquid interfaces SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SUM-FREQUENCY SPECTROSCOPY; SELF-ASSEMBLED MONOLAYERS; SODIUM DODECYL-SULFATE; VIBRATIONAL SPECTROSCOPY; HYDROPHOBIC SURFACE; WATER-INTERFACE; ALKYL CHAIN; MOLECULAR-DYNAMICS; WETTING PROPERTIES; LIQUID INTERFACE AB Sum-frequency surface vibrational spectroscopy was used to study chain conformation of self-assembled surfactant monolayers at various quartz/alkane and quartz/alcohol interfaces as a function of surfactant surface density and chain lengths of both surfactant and alkane or alcohol molecules. We found that, in comparison with fully packed monolayers such as octadecyltrichlorosilane (OTS) on glass or alkanethiols on gold, the chain conformation of loosely packed monolayers is considerably more sensitive to their environment. With sufficiently high surfactant surface density and sufficiently long chain lengths of both surfactant and alkane, the chain-chain interaction between surfactant and alkane molecules can effectively eliminate all the gauche defects initially present in the surfactant chains. With alkanes replaced by alcohols the hydrophobic effect appears to be dominant, as the alcohol molecules like to form a hydrogen-bonding network at an interface with the hydroxyl groups facing the surfactant monolayer. This causes the surfactant chains to curl up. However, if the long-chain alcohols are diluted in a nonpolar liquid, the hydrogen-bonding network is disrupted and the alcohol can now adsorb individually at the interface. Then again, the chain-chain interaction dominates and if it is sufficiently strong, the chains become all-trans. Our results are relevant for proper interpretation of wetting phenomena on self-assembled monolayers and provide a microscopic understanding of the interplay between interfacial structure and intermolecular interactions between monolayers and the surrounding liquid. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Shen, YR (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. EM shenyr@socrates.berkeley.edu RI Miranda, Paulo/C-5933-2012 OI Miranda, Paulo/0000-0002-2890-0268 NR 65 TC 52 Z9 53 U1 1 U2 31 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 NOV 25 PY 1998 VL 120 IS 46 BP 12092 EP 12099 DI 10.1021/ja9732441 PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 142QD UT WOS:000077210900030 ER PT J AU Nijhuis, M Boucher, CAB Schipper, P Leitner, T Schuurman, R Albert, J AF Nijhuis, M Boucher, CAB Schipper, P Leitner, T Schuurman, R Albert, J TI Stochastic processes strongly influence HIV-1 evolution during suboptimal protease-inhibitor therapy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HUMAN-IMMUNODEFICIENCY-VIRUS; DYNAMICS IN-VIVO; REVERSE-TRANSCRIPTASE; RESISTANCE MUTATIONS; GENETIC BOTTLENECKS; ZIDOVUDINE THERAPY; DRUG-RESISTANCE; MULLER RATCHET; PROVIRAL DNA; TYPE-1 RNA AB It has long been assumed that HIV-1 evolution is best described by deterministic evolutionary models because of the large population size, Recently, however, it was suggested that the effective population size (N-e) may be rather small, thereby allowing chance to influence evolution, a situation best described by a stochastic evolutionary model. To gain experimental evidence supporting one of the evolutionary models, we investigated whether the development of resistance to the protease inhibitor ritonavir affected the evolution of the env gene. Sequential serum samples from five patients treated with ritonavir were used for analysis of the protease gene and the V3 domain of the env gene. Multiple reverse transcription-PCR products were cloned, sequenced, and used to construct phylogenetic trees and to calculate the genetic variation and N-e. Genotypic resistance to ritonavir developed in all five patients, but each patient displayed a unique combination of mutations, indicating a stochastic element in the development of ritonavir resistance. Furthermore, development of resistance induced clear bottleneck effects in the env gene. The mean intrasample genetic variation, which ranged from 1.2% to 5.7% before treatment, decreased significantly (P < 0.025) during treatment, In agreement with these findings, N-e was estimated to be very small (500-15,000) compared with the total HIV-1 RNA copy number. This study combines three independent observations, strong population bottlenecking, small N-e, and selection of different combinations of protease-resistance mutations, all of which indicate that HIV-1 evolution is best described by a stochastic evolutionary model. C1 Univ Utrecht Hosp, Dept Virol, Eijkman Winkler Inst, NL-3584 CX Utrecht, Netherlands. Swedish Inst Infect Dis Control, Dept Clin Virol, S-10521 Stockholm, Sweden. Univ Calif Los Alamos Natl Lab, Grp T10, Los Alamos, NM 87545 USA. RP Boucher, CAB (reprint author), Univ Utrecht Hosp, Dept Virol, Eijkman Winkler Inst, Heidelberglaan 100, NL-3584 CX Utrecht, Netherlands. NR 49 TC 115 Z9 116 U1 0 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 24 PY 1998 VL 95 IS 24 BP 14441 EP 14446 DI 10.1073/pnas.95.24.14441 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 142GE UT WOS:000077191200081 PM 9826719 ER PT J AU Kitamura, K Furukawa, Y Niwa, K Gopalan, V Mitchell, TE AF Kitamura, K Furukawa, Y Niwa, K Gopalan, V Mitchell, TE TI Crystal growth and low coercive field 180 degrees domain switching characteristics of stoichiometric LiTaO3 SO APPLIED PHYSICS LETTERS LA English DT Article ID CRUCIBLE CZOCHRALSKI METHOD; LITHIUM TANTALATE; LINBO3; GENERATION AB We grew LiTaO3 single crystals with a composition close to stoichiometry by using a double crucible Czochralski method. The switching field required for 180 degrees ferroelectric domain reversal and the internal fields originating from nonstoichiometric point defects were compared for the stoichiometric and conventional commercially available crystals. The switching fields for the domain reversal in the stoichiometric crystal with a Curie temperature of 685 degrees C was 1.7 kV/mm. This is about one thirteenth of the switching field required for the conventional LiTaO3 crystals with a Curie temperature near 600 degrees C. The internal field in the stoichiometric crystal drastically decreased to 0.1 kV/mm. (C) 1998 American Institute of Physics. [S0003-6951(98)00847-X]. C1 Natl Inst Res Inorgan Mat, Tsukuba, Ibaraki 3050044, Japan. NGK Spark Plug Co Ltd, Komaki 4858510, Japan. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Kitamura, K (reprint author), Natl Inst Res Inorgan Mat, 1-1 Namiki, Tsukuba, Ibaraki 3050044, Japan. NR 12 TC 202 Z9 208 U1 3 U2 34 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 NOV 23 PY 1998 VL 73 IS 21 BP 3073 EP 3075 DI 10.1063/1.122676 PG 3 WC Physics, Applied SC Physics GA 140AR UT WOS:000077063800017 ER PT J AU Sieg, RM Carlin, JA Boeckl, JJ Ringel, SA Currie, MT Ting, SM Langdo, TA Taraschi, G Fitzgerald, EA Keyes, BM AF Sieg, RM Carlin, JA Boeckl, JJ Ringel, SA Currie, MT Ting, SM Langdo, TA Taraschi, G Fitzgerald, EA Keyes, BM TI High minority-carrier lifetimes in GaAs grown on low-defect-density Ge/GeSi/Si substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID SOLAR-CELLS; SI; FILMS AB A high bulk minority-carrier lifetime in GaAs grown on Si-based substrates is demonstrated. This was achieved by utilizing a step-graded Ge/GeSi buffer (threading dislocation density 2 x 10(6) cm(-2)) grown on an offcut (001) Si wafer, coupled with monolayer-scale control of the GaAs nucleation to suppress antiphase domains. Bulk minority-carrier lifetimes (tau(p)) were measured using room-temperature time-resolved photoluminescence applied to a series of Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As double-heterojunction structures doped n = 1.1 x 10(17) cm(-3) with GaAs thicknesses of 0.5, 1.0, and 1.5 mu m. A lifetime tau(p) = 7.7 ns was determined for GaAs grown on Si. The extracted interface recombination velocity of 3.9 x 10(3) cm/s is comparable to recombination velocities found for Al0.3Ga0.7As/GaAs interfaces grown on both GaAs and Ge wafers, indicating that the crossbatch surface morphology characteristic of strain-relaxed Ge/GeSi surfaces does not impede the formation of high-electronic-quality interfaces. These results hold great promise for future integration of III-V minority-carrier devices with Si wafer technologies. (C) 1998 American Institute of Physics [S0003-6951(98)00447-1]. C1 Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. MIT, Cambridge, MA 02139 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Sieg, RM (reprint author), Ohio State Univ, Dept Elect Engn, Columbus, OH 43210 USA. NR 17 TC 67 Z9 67 U1 3 U2 22 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 NOV 23 PY 1998 VL 73 IS 21 BP 3111 EP 3113 DI 10.1063/1.122689 PG 3 WC Physics, Applied SC Physics GA 140AR UT WOS:000077063800030 ER PT J AU Crone, BK Campbell, IH Davids, PS Smith, DL AF Crone, BK Campbell, IH Davids, PS Smith, DL TI Charge injection and transport in single-layer organic light-emitting diodes SO APPLIED PHYSICS LETTERS LA English DT Article ID POLYMER; ELECTRON; DEVICES; MODEL AB We present experimental and device model results for the current-voltage characteristics of a series of organic diodes. We consider three general types of structures: electron only, hole only, and bipolar devices. Electron and hole mobility parameters are extracted from the corresponding single carrier structures and then used to describe the bipolar devices. The device model successfully describes the experimental results for: electron only devices as thickness is varied, hole only devices as the contact metals are varied, and bipolar devices are both the thickness and the contact metals are varied. (C) 1998 American Institute of Physics. [S0003-6951(98)00547-6]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Crone, BK (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Davids, Paul/D-1550-2010 NR 15 TC 63 Z9 65 U1 1 U2 11 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 NOV 23 PY 1998 VL 73 IS 21 BP 3162 EP 3164 DI 10.1063/1.122706 PG 3 WC Physics, Applied SC Physics GA 140AR UT WOS:000077063800047 ER PT J AU Laissue, JA Geiser, G Spanne, PO Dilmanian, FA Gebbers, JO Geiser, M Wu, XY Makar, MS Micca, PL Nawrocky, MM Joel, DD Slatkin, DN AF Laissue, JA Geiser, G Spanne, PO Dilmanian, FA Gebbers, JO Geiser, M Wu, XY Makar, MS Micca, PL Nawrocky, MM Joel, DD Slatkin, DN TI Neuropathology of ablation of rat gliosarcomas and contiguous brain tissues using a microplanar beam of synchrotron-wiggler-generated X rays SO INTERNATIONAL JOURNAL OF CANCER LA English DT Article ID NEUTRON-CAPTURE THERAPY AB Adult-rat-brain tissues display an unusually high resistance to necrosis when serially irradiated with parallel, thin slices of a microplanar (i.e., microscopically thin and macroscopically broad) beam of synchrotron-wiggler-generated, approx. 35-120 keV (median approx, 50 keV) Gd-filtered X rays at skin-entrance absorbed doses of 312 to 5000 Gy per slice. Such microplanar beams were used to irradiate young adult rats bearing right frontocerebral 9L gliosarcomas (approx. 4 mm diameter), through a volume of tissue containing the tumor and contiguous brain tissue, either in a single array or in 2 orthogonally crossed arrays of tissue slices. Each array included 101 parallel microplanar slices, 100 mu m center-to-center distance, each slice being approx. 25 mu m wide and 12 mm high, with skin-entrance absorbed doses of 3 12.5 Gy or 625 Gy per slice. Compared with unirradiated controls with a median survival time of 20 days after tumor initiation, the median survival time was extended in irradiated rats by 139 days (625 Gy, crossed arrays), 96 days (312.Gy, crossed arrays) or 24 days (625 Gy, single array). The tumors disappeared in 22 of the 36 irradiated rats, 4/11 even alter unidirectional microbeam irradiation. The extent and severity of radiation damage to the normal brain in rats with or without tumor was graded histopathologically. Correlation of those grades with radiation doses shows that loss of tissue structure was confined to beam-crossing regions and Chat only minor damage was done to zones of the brain irradiated unidirectionally. (C) 1998 Wiley-Liss, Inc. C1 Univ Bern, Inst Pathol, CH-3010 Bern, Switzerland. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Cantonal Hosp, Inst Pathol, Lucerne, Switzerland. Univ Bern, Inst Anat, Bern, Switzerland. RP Laissue, JA (reprint author), Univ Bern, Inst Pathol, Murtenstr 31 Postfach, CH-3010 Bern, Switzerland. EM laissue@patho.unibe.ch NR 19 TC 156 Z9 158 U1 2 U2 8 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0020-7136 J9 INT J CANCER JI Int. J. Cancer PD NOV 23 PY 1998 VL 78 IS 5 BP 654 EP 660 DI 10.1002/(SICI)1097-0215(19981123)78:5<654::AID-IJC21>3.0.CO;2-L PG 7 WC Oncology SC Oncology GA 134YV UT WOS:000076772100021 PM 9808538 ER PT J AU Bennett, JS Bell, DW Buchholz, BA Kwok, ESC Vogel, JS Morton, TH AF Bennett, JS Bell, DW Buchholz, BA Kwok, ESC Vogel, JS Morton, TH TI Accelerator mass spectrometry for assaying irreversible covalent modification of an enzyme by acetoacetic ester SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE aldolase; crosslinking; isotope ratio; protein; radiocarbon ID IDENTIFICATION; SENSE AB Protein modification (sometimes known as crosslinking) often requires two or more steps to affix a small molecule irreversibly. Two-step reductive alkylation of the enzyme rabbit muscle aldolase with ethyl 3-C-14-acetoacetate and sodium cyanoborohydride attaches less radioactivity than with cyanoborohydride omitted. The C-14 level incorporated into aldolase corresponds to only about 15-30 modified protein molecules per million. Accelerator mass spectrometry (AMS) provides the only technique currently available for investigating the shorter chains from CNBr-cleavage of modified aldolase. Examination of individual fragments reveals that reductive alkylation of the active site lysine in the presence of cyanoborohydride (+BH3CN) is negligible when compared with the extent of covalent modification in the absence of cyanoborohydride (-BH3CN). Labeling by ethyl acetoacetate cannot result from simple acetoacetylation, because dialysis with hydroxylamine does not wash it out. The amount of C-14 incorporated from ethyl 3-C-14-acetoacetate without cyanoborohydride is roughly proportional to the number of tyrosine residues in each CNBr-fragment, and we surmise that ethyl acetoacetate attaches irreversibly via a reaction specific to that amino acid. Cyanoborohydride inhibits this reaction, but appears to diminish the susceptibility of the active site tyrosine (which is close to a lysine in the tertiary structure of aldolase) less than other tyrosine residues. (Int J Mass Spectrom 179/180 (1998) 185-193) (C) 1998 Elsevier Science B.V. C1 Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA. Univ Calif Lawrence Livermore Natl Lab, Ctr Accelerator Mass Spectrometry, Livermore, CA 94550 USA. RP Morton, TH (reprint author), Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA. RI Buchholz, Bruce/G-1356-2011 NR 17 TC 1 Z9 1 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 EI 1873-2798 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD NOV 23 PY 1998 VL 179 BP 185 EP 193 DI 10.1016/S1387-3806(98)14177-5 PG 9 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 140RD UT WOS:000077101400020 ER PT J AU Paddison, SJ Reagor, DW Zawodzinski, TA AF Paddison, SJ Reagor, DW Zawodzinski, TA TI High frequency dielectric studies of hydrated Nafion (R) SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT Electrochemical-Society Symposium on Processes in Polymers and Polymer/Metal Interfaces CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc DE conductivity; dielectric constant; high frequency; Nafion (R); transport mechanism; water content ID CONTAINING PERFLUOROSULFONATE IONOMERS; PRESSURE ELECTRICAL-CONDUCTIVITY; ION MOTIONS; POLYMER ELECTROLYTES; WATER-UPTAKE; MEMBRANES; RELAXATION; TRANSPORT; SYSTEMS; NMR AB This study reports high frequency dielectric measurements (0.045-30 GHz) on Nafion(R) 117 at various states of hydration. A novel technique to measure the broad band frequency dependent real and imaginary parts of the relative permittivity is described. The basic experimental configuration and numerical data analysis are reported along with a discussion of several difficulties encountered and experimental validation of the method. The preliminary results show a strong dependence of the dielectric constant of the Nafion(R) 117 membrane with water content. The dielectric constant for all hydrated membrane samples was observed to be constant over the initial part of the frequency span, ranging from a maximum of 20 in the samples with 13 waters per sulfonate to a minimum of four in very dry samples. The results reflect the decreasing polar environment of the water at low water contents as well as the increasing extent of binding of the water at the fixed ionic site at low water content. A 'roll off' in the dielectric constant, the extent of which was dependent on water content, was observed also in the frequency spectrum. Several possible origins for this 'roll-off', including real effects of dipolar relaxations occurring in the hydrated polymers and experimental effects due to the similarity of the wavelength of radiation to the sample dimensions are discussed. Finally, the conductivity of the membranes at various water contents and at frequencies below 5 GHz was extracted from the loss factor spectra. These values agreed well with previous conductivity measurements (obtained at lower frequencies) suggesting that no relaxations are observed in the intervening frequency range (roughly 5-50 MHz). (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Paddison, SJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. EM pad-dison@lanl.gov RI Paddison, Stephen/B-2935-2014 NR 23 TC 77 Z9 77 U1 0 U2 16 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 NOV 23 PY 1998 VL 459 IS 1 BP 91 EP 97 DI 10.1016/S0022-0728(98)00321-0 PG 7 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 153PW UT WOS:000077842300009 ER PT J AU Dai, HL Zawodzinski, TA AF Dai, HL Zawodzinski, TA TI The dependence of lithium transference numbers on temperature, salt concentration and anion type in poly (vinylidene fluoride)-hexafluoropropylene copolymer-based gel electrolytes SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT Electrochemical-Society Symposium on Processes in Polymers and Polymer/Metal Interfaces CY MAY 04-09, 1997 CL MONTREAL, CANADA SP Electrochem Soc DE transference numbers; gel electrolytes; polymers AB The electrophoretic NMR method was used to measure lithium transference numbers in gel electrolytes consisting of various salts in propylene carbonate-swollen poly (vinylidene fluoride)-hexafluoropropylene copolymer. We compare the concentration dependence of the lithium transference numbers obtained for a series of anions. The anions considered are CF3SO3- (Tf), N(CF3SO2)(2)(-) (TFSI), N(C2F5SO2)(2)(-) (BETI) and (C(CF3SO2)(3)(-) (TFSM). Larger anions were generally found to result in higher lithium transference numbers. t(Li) in LiTf containing electrolytes decreases steadily with the salt concentration. However, in LiTFSI-containing gel electrolytes, t(Li) is almost invariant over a large concentration range. The results are discussed in the context of the effect of ion-ion interaction, the extent of which is dependent on the degree of anion charge delocalization. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zawodzinski, TA (reprint author), Univ Calif Los Alamos Natl Lab, MST-11,MS D429, Los Alamos, NM 87545 USA. EM za-wod@lanl.gov NR 10 TC 39 Z9 40 U1 1 U2 17 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 NOV 23 PY 1998 VL 459 IS 1 BP 111 EP 119 DI 10.1016/S0022-0728(98)00373-8 PG 9 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA 153PW UT WOS:000077842300011 ER PT J AU Cao, H Zhang, R Yuan, JP Huang, CM Jean, YC Suzuki, R Ohdaira, T Nielsen, B AF Cao, H Zhang, R Yuan, JP Huang, CM Jean, YC Suzuki, R Ohdaira, T Nielsen, B TI Free-volume hole model for positronium formation in polymers: surface studies SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article; Proceedings Paper CT International Symposium on the Electronic and Defect Structure of Materials CY MAR 26-28, 1998 CL UNIV EAST ANGLIA, NORWICH, ENGLAND HO UNIV EAST ANGLIA ID ANNIHILATION LIFETIME MEASUREMENTS; AMORPHOUS POLYMERS; SPECTROSCOPY; COPOLYESTERS; PROBE; FILMS AB Positron annihilation lifetime and Doppler broadening of annihilation radiation experiments are performed in a polyurethane film using the mono-energetic slow positron probe as a function of positron energies. Significant variations of positron annihilation signals are observed at a short distance from the surface (<100 nm). The ortho-positronium lifetime in the polymer increases near the surface, while its intensity decreases. The intensity results are consistent with the description of a free-volume hole model for positronium formation proposed by Brandt, Berko and Walker. This study further confirms that positron annihilation spectroscopy is a sensitive probe for the characterization of physical properties of sub-nanometre defects, such as free volumes and holes for polymeric materials. C1 Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. Electrotech Lab, Tsukuba, Ibaraki 305, Japan. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11972 USA. RP Univ Missouri, Dept Chem, Kansas City, MO 64110 USA. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 29 TC 58 Z9 58 U1 0 U2 5 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 NOV 23 PY 1998 VL 10 IS 46 BP 10429 EP 10442 DI 10.1088/0953-8984/10/46/011 PG 14 WC Physics, Condensed Matter SC Physics GA 146LP UT WOS:000077430800011 ER PT J AU Lukens, WW Matsunaga, PT Andersen, RA AF Lukens, WW Matsunaga, PT Andersen, RA TI Synthesis and structure of Cp*2TiH, Cp*2TiH2Li(tmed), and [Cp*2TiOLi(THF)](2) SO ORGANOMETALLICS LA English DT Article ID ELECTRON-PARAMAGNETIC RESONANCE; PERMETHYLTITANOCENE HYDRIDE; COMPLEXES; DERIVATIVES; LITHIUM; SPECTRA; (ETA-5-C5ME5)2TIR; NITROGEN; COMPOUND; METHYL AB The solid-state crystal structure of the d(1) hydride Cp*2TiH shows that it has a bent sandwich structure with an open Cp*(centroid)-Ti-Cp*(centroid) angle of 150 degrees. The crystal structure contains two molecules in the asymmetric unit, and the hydridic hydrogen atom is located and refined with isotropic thermal parameters to a Ti-H distance of 1.69(5) and 1.84(4) Angstrom in each independent molecule; the average Ti-H distance is 1.76 Angstrom. In each molecule, the Ti-H vector lies on the idealized C-2 axis of the bent metallocene. The addition of n-BuLi and Me2NCH2CH2NMe2 (tmed) in hexane to Cp*2TiH or the addition of [Li(tmed)](2)C10H8 to Cp*2TiCl gives the anionic dihydride Cp*Ti-2(mu-H)(2)Li(tmed). The hydride atoms are not located in the X-ray diffraction experiment, but electron paramagnetic resonance spectra show coupling to two equivalent hydrogen nuclei, A(H)(iso) = 9.6 G. In addition, coupling to Li-7, confirmed by the preparation of the Li-6 isotopomer, shows that the unpaired electron couples with each;hydridic hydrogen and lithium nucleus. The proposed structure has two hydride ligands bridging the Cp*Ti-2 and Li(tmed) fragments. Water in tetrahydrofuran (THF) reacts with Cp*Ti-2(mu-H)(2)Li(tmed) to give the dimer, [Cp*2TiOLi(THF)](2). Its X-ray structure shows that the two Cp*2TiO fragments are joined together by the Li(THF) fragments such that the Li2O2 unit; is a square as found in dimeric lithium alkoxides; in this case, the alkoxide is the metallocene Cp*2TiO-. Variable-temperature magnetic susceptibility shows that the unpaired electrons on each Cp*2TiO- fragment are not coupled down to 5 K. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Andersen, RA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Chem, Berkeley, CA 94720 USA. NR 40 TC 36 Z9 36 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD NOV 23 PY 1998 VL 17 IS 24 BP 5240 EP 5247 DI 10.1021/om980601n PG 8 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 144VX UT WOS:000077337000010 ER PT J AU Toupadakis, A Kubas, GJ King, WA Scott, BL Huhmann-Vincent, J AF Toupadakis, A Kubas, GJ King, WA Scott, BL Huhmann-Vincent, J TI Comparative binding of H-2, N-2, and related ligands to [Mn(CO)(3)(PCy3)(2)](+) and other 16e electrophiles. N-2 does not coordinate, and H-2 is the most versatile weak ligand SO ORGANOMETALLICS LA English DT Article ID MOLECULAR-HYDROGEN COMPLEXES; METAL DIHYDROGEN COMPLEXES; H-H BOND; M = CR; TRANSITION-METALS; ELECTRONIC CONTROL; DIHYDRIDE COORDINATION; MOLYBDENUM COMPLEXES; 16-ELECTRON COMPLEX; CARBONYL-COMPLEXES AB The photochemical reaction of Mn(CO)(5)Br with PCy3 in toluene proceeds with the fast evolution of CO. The complex formed, MnBr(CO)(3)(PCy3)(2), 1, readily reacts with NaA (A = B[C6H3(3,5-CF3)(2)](4)) to form the dark green salt [Mn(CO)(3)(PCy3)(2)][A], 2, which has an agostic interaction of a cyclohexyl C-H with manganese. The light yellow eta(2)-H-2 complex, [Mn(H-2)-(CO)(3)(PCY3)(2)][A], 3, forms at room temperature by placing solutions of 2 under 1 atm of H-2. The H-2 ligand is labile and readily dissociates when the H-2 atmosphere is removed in vacuo. P-31 NMR clearly shows that at 25 degrees C under 1 atm of H-2, 3 exists in equilibrium with 2. At -78 degrees C and under <1 atm of H-2, only 3 is observed. The synthesis of the new tricarbonyl complex [Mn(CO)(3)(PCy3)(2)](+) provides an excellent system of comparison for the binding of small molecules to similar known 16e fragments such as M(CO)(3)(PCy3)(2) (M = Cr, Mo, W, Re+) and M(CO)(dppe)(2) (M = Mo, Mn+). The cationic manganese complex 2 appears to give somewhat more stable binding of H-2 than the isoelectronic neutral chromium congener, which would not have been expected on the basis of relative back-bonding ability of the metal centers. Thus it is clear that increased sigma-donation more than compensates for decreased back-bonding in the relative metal-H-2 bonding energies. Surprisingly, binding of N-2, ethylene, or silanes to 2 was not observed in solution even at low temperature and SO2 binds only weakly. By comparison with other similar systems, it is clear that H-2 becomes an increasingly better ligand than N-2 as the electrophilicity of the metal increases. Thus nonclassical H-2 is a more versatile ligand than most classical ligands in its ability to adjust to a larger range of electronic situations. C1 Univ Crete, Dept Chem, GR-71110 Iraklion, Crete, Greece. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Toupadakis, A (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,Mail Stop L-092, Livermore, CA 94551 USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 66 TC 38 Z9 38 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD NOV 23 PY 1998 VL 17 IS 24 BP 5315 EP 5323 DI 10.1021/om980560v PG 9 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA 144VX UT WOS:000077337000019 ER PT J AU Glendenning, NK Schaffner-Bielich, J AF Glendenning, NK Schaffner-Bielich, J TI Kaon condensation and dynamical nucleons in neutron stars SO PHYSICAL REVIEW LETTERS LA English DT Article ID MATTER; PHASE; EQUATION; STATE AB We discuss the nature of the kaon condensation phase transition. We find several remarkable features which, if kaons condense in neutron stars, will surely affect superfluidity and transport properties. The mixed phase region occupying a large fraction of the star is permeated with microscopic drops located at lattice sites of one phase immersed in the background of the other phase. The electric charge in the drops is apposite to that of the background phase and nucleons have a mass approximately a factor of 2 different depending on whether they are in the drops or the background phase. [S0031-9007(98)07730-8]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Inst Nucl & Particle Astrophys, Berkeley, CA 94720 USA. RP Glendenning, NK (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 26 TC 124 Z9 124 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 NOV 23 PY 1998 VL 81 IS 21 BP 4564 EP 4567 DI 10.1103/PhysRevLett.81.4564 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300009 ER PT J AU Bochna, C Terburg, BP Abbott, DJ Ahmidouch, A Armstrong, CS Arrington, J Assamagan, KA Baker, OK Barrow, SP Beatty, DP Beck, DH Beedoe, SY Beise, EJ Belz, JE Bosted, PE Brash, EJ Breuer, H Cadman, RV Cardman, L Carlini, RD Cha, J Chant, NS Collins, G Cothran, C Cummings, WJ Danagoulian, S Duncan, FA Dunne, JA Dutta, D Eden, T Ent, R Filippone, BW Forest, TA Fortune, HT Frolov, VV Gao, H Geesaman, DF Gilman, R Gueye, PLJ Gustafsson, KK Hansen, JO Harvey, M Hinton, W Holt, RJ Jackson, HE Keppel, CE Khandaker, MA Kinney, ER Klein, A Koltenuk, DM Kumbartzki, G Lung, AF Mack, DJ Madey, R Markowitz, P McFarlane, KW McKeown, RD Meekins, DG Meziani, ZE Miller, MA Mitchell, JH Mkrtchyan, HG Mohring, RM Napolitano, J Nathan, AM Niculescu, G Niculescu, I O'Neill, TG Owen, BR Pate, SF Potterveld, DH Price, JW Rakness, GL Ransome, R Reinhold, J Rutt, PM Salgado, CW Savage, G Segel, RE Simicevic, N Stoler, P Suleiman, R Tang, L van Westrum, D Vulcan, WF Williamson, S Witkowski, MT Wood, SA Yan, C Zeidman, B AF Bochna, C Terburg, BP Abbott, DJ Ahmidouch, A Armstrong, CS Arrington, J Assamagan, KA Baker, OK Barrow, SP Beatty, DP Beck, DH Beedoe, SY Beise, EJ Belz, JE Bosted, PE Brash, EJ Breuer, H Cadman, RV Cardman, L Carlini, RD Cha, J Chant, NS Collins, G Cothran, C Cummings, WJ Danagoulian, S Duncan, FA Dunne, JA Dutta, D Eden, T Ent, R Filippone, BW Forest, TA Fortune, HT Frolov, VV Gao, H Geesaman, DF Gilman, R Gueye, PLJ Gustafsson, KK Hansen, JO Harvey, M Hinton, W Holt, RJ Jackson, HE Keppel, CE Khandaker, MA Kinney, ER Klein, A Koltenuk, DM Kumbartzki, G Lung, AF Mack, DJ Madey, R Markowitz, P McFarlane, KW McKeown, RD Meekins, DG Meziani, ZE Miller, MA Mitchell, JH Mkrtchyan, HG Mohring, RM Napolitano, J Nathan, AM Niculescu, G Niculescu, I O'Neill, TG Owen, BR Pate, SF Potterveld, DH Price, JW Rakness, GL Ransome, R Reinhold, J Rutt, PM Salgado, CW Savage, G Segel, RE Simicevic, N Stoler, P Suleiman, R Tang, L van Westrum, D Vulcan, WF Williamson, S Witkowski, MT Wood, SA Yan, C Zeidman, B TI Measurements of deuteron photodisintegration up to 4.0 GeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM CHROMODYNAMICS; AMPLITUDES; SCATTERING; HADRONS; MODEL AB The first measurements of the differential cross section for the d(gamma,p)n reaction up to 4.0 GeV were performed at the Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson Laboratory. We report the cross sections at the proton center-of-mass angles of 36 degrees, 52 degrees, 69 degrees, and 89 degrees. These results are in reasonable agreement with previous measurements at lower energy. The 89 degrees and 69 degrees data show constituent-counting-rule behavior up to 4.0 GeV photon energy. The 52 degrees and 36 degrees data disagree with the counting-rule behavior. The quantum chromodynamics; (QCD) model of nuclear reactions involving reduced amplitudes disagrees with the present data. [S0031-9007(98)07676-5]. C1 Univ Illinois, Urbana, IL 61801 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Kent State Univ, Kent, OH 44242 USA. Coll William & Mary, Williamsburg, VA 23187 USA. CALTECH, Pasadena, CA 91125 USA. Hampton Univ, Hampton, VA 23668 USA. Univ Penn, Philadelphia, PA 19104 USA. N Carolina Agr & Technol State Univ, Greensboro, NC 27411 USA. Univ Maryland, College Pk, MD 20742 USA. TRIUMF, Vancouver, BC V6T 2A3, Canada. American Univ, Washington, DC 20016 USA. Univ Regina, Regina, SK S4S 0A2, Canada. Univ Virginia, Charlottesville, VA 22901 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Northwestern Univ, Evanston, IL 60201 USA. Rensselaer Polytech Inst, Troy, NY 12180 USA. MIT, Cambridge, MA 02139 USA. Rutgers State Univ, New Brunswick, NJ 08903 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Univ Colorado, Boulder, CO 80309 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Florida Int Univ, Miami, FL 33199 USA. Temple Univ, Philadelphia, PA 19122 USA. Yerevan Phys Inst, Yerevan 375036, Armenia. New Mexico State Univ, Las Cruces, NM 88003 USA. RP Bochna, C (reprint author), Univ Illinois, Urbana, IL 61801 USA. RI Gao, Haiyan/G-2589-2011; Arrington, John/D-1116-2012; Holt, Roy/E-5803-2011 OI Arrington, John/0000-0002-0702-1328; NR 23 TC 102 Z9 102 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 NOV 23 PY 1998 VL 81 IS 21 BP 4576 EP 4579 DI 10.1103/PhysRevLett.81.4576 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300012 ER PT J AU Shvartsburg, AA Jarrold, MF Liu, B Lu, ZY Wang, CZ Ho, KM AF Shvartsburg, AA Jarrold, MF Liu, B Lu, ZY Wang, CZ Ho, KM TI Dissociation energies of silicon clusters: A depth gauge for the global minimum on the potential energy surface SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-DYNAMICS; THERMODYNAMIC PROPERTIES; SPECTRA; IONS; PHOTOFRAGMENTATION; PHOTODETACHMENT; SI AB We have modeled the dissociation of Si-n neutrals and cations in the n less than or equal to 26 range. The fragmentation pathways up to n = 26 and dissociation energies up to n = 20 have been calculated assuming a statistical decomposition process. The results for the cations are in good agreement with the measurements. This indicates that our search of configuration space for the silicon clusters in this size range has indeed found the global minima-a family of "stacked Si-9 tricapped trigonal prisms." This is the first time that dissociation energies have been used to test the results of a global optimization. [S0031-9007(98)07726-6]. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Shvartsburg, AA (reprint author), Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI 上官, 敏慧/E-8964-2012 NR 35 TC 69 Z9 69 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 NOV 23 PY 1998 VL 81 IS 21 BP 4616 EP 4619 DI 10.1103/PhysRevLett.81.4616 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300022 ER PT J AU He, GW Chen, SY Kraichnan, RH Zhang, RY Zhou, Y AF He, GW Chen, SY Kraichnan, RH Zhang, RY Zhou, Y TI Statistics of dissipation and enstrophy induced by localized vortices SO PHYSICAL REVIEW LETTERS LA English DT Article ID SMALL-SCALE STRUCTURES; ISOTROPIC TURBULENCE; 3-DIMENSIONAL TURBULENCE; VELOCITY; VORTEX; INTERMITTENCY; INSTABILITY; TRANSVERSE; LAWS AB The ratios of enstrophy and dissipation moments induced by localized vorticity are inferred to be finite. It follows that the scaling exponents for locally averaged dissipation and enstrophy are equal. However, enstrophy and dissipation exponents measured over finite ranges of scales may be different. The cylindrical vortex profile that yields maximal moment ratios is determined. The moment ratios for cylindrical vortices are used to interpret differences in scale dependence of enstrophy and dissipation previously found in numerical simulations. [S0031-9007(98)07782-5]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. IBM Corp, Div Res, TJ Watson Res Ctr, Yorktown Heights, NY 10598 USA. Chinese Acad Sci, Inst Mech, LNM, Beijing 100080, Peoples R China. RP He, GW (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Chen, Shiyi/A-3234-2010 NR 20 TC 36 Z9 36 U1 4 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 NOV 23 PY 1998 VL 81 IS 21 BP 4636 EP 4639 DI 10.1103/PhysRevLett.81.4636 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300027 ER PT J AU Watt, RG Duke, J Fontes, CJ Gobby, PL Hollis, RV Kopp, RA Mason, RJ Wilson, DC Verdon, CP Boehly, TR Knauer, JP Meyerhofer, DD Smalyuk, V Town, RPJ Iwase, A Willi, O AF Watt, RG Duke, J Fontes, CJ Gobby, PL Hollis, RV Kopp, RA Mason, RJ Wilson, DC Verdon, CP Boehly, TR Knauer, JP Meyerhofer, DD Smalyuk, V Town, RPJ Iwase, A Willi, O TI Laser imprint reduction using a low-density foam buffer as a thermal smoothing layer at 351-nm wavelength SO PHYSICAL REVIEW LETTERS LA English DT Article ID TARGETS; DRIVEN AB Laser-nonuniformity-induced perturbation growth has been measured on planar foam-buffered plastic (CII) targets irradiated with 351-nm laser radiation. The maximum observed perturbation growth was reduced by about 50% by the foam buffer. Rayleigh-Taylor unstable growth of intentional mass modulations was minimally changed by the addition of the foam buffer. We conclude that the reduction of laser-induced perturbation growth is a result of a reduction in the perturbation seed amplitude rather than any changes in the growth rate in the solid due to preheating by radiation or shocks caused by the presence of the foam buffer. [S0031-9007(98)07706-0]. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Rochester, Laser Energet Lab, Rochester, NY 14627 USA. Univ London Imperial Coll Sci Technol & Med, London, England. RP Watt, RG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 13 TC 23 Z9 26 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 NOV 23 PY 1998 VL 81 IS 21 BP 4644 EP 4647 DI 10.1103/PhysRevLett.81.4644 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300029 ER PT J AU Hughes, DA Chrzan, DC Liu, Q Hansen, N AF Hughes, DA Chrzan, DC Liu, Q Hansen, N TI Scaling of misorientation angle distributions SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY DISLOCATION-STRUCTURES; PLASTIC-DEFORMATION; BOUNDARIES; CRYSTALS; STEELS; CREEP AB The measurement of misorientation angle distributions following different amounts of deformation in cold-rolled aluminum and nickel and compressed stainless steel is reported. The sealing of the dislocation cell boundary misorientation angle distributions is studied. Surprisingly, the distributions for the small to large strain regimes for aluminum, 304L stainless steel, nickel, and copper (taken from the literature )appear to be identical. Hence the distributions may be "universal." These results have significant implications for the development of dislocation based deformation models. [S0031-9007(98)07728-X]. C1 Sandia Natl Labs, Ctr Mat & Appl Mech, Livermore, CA 94550 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Riso Natl Lab, Dept Mat, DK-4000 Roskilde, Denmark. RP Hughes, DA (reprint author), Sandia Natl Labs, Ctr Mat & Appl Mech, Livermore, CA 94550 USA. NR 26 TC 113 Z9 117 U1 3 U2 25 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 NOV 23 PY 1998 VL 81 IS 21 BP 4664 EP 4667 DI 10.1103/PhysRevLett.81.4664 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300034 ER PT J AU Hannon, JB Bartelt, MC Bartelt, NC Kellogg, GL AF Hannon, JB Bartelt, MC Bartelt, NC Kellogg, GL TI Etching of the Si(001) surface with molecular oxygen SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRON-MICROSCOPY; ATOMIC OXYGEN; SI(100); ADSORPTION; TEMPERATURES; SI(111); BEAM; SIO AB We have used low-energy electron microscopy to study the etching of large terraces on Si(001) with molecular oxygen. By imaging the etching process in situ, and comparing the results to detailed kinetic models, we determine and quantify the dominant mechanisms by which oxygen attacks the surface. We find that the etch rate follows an Arrhenius form with an activation energy of 2.0 +/- 0.4 eV, significantly lower than estimates reported in modulated beam investigations. [S0031-9007(98)07716-3]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Hannon, JB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 15 TC 31 Z9 31 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 23 PY 1998 VL 81 IS 21 BP 4676 EP 4679 DI 10.1103/PhysRevLett.81.4676 PG 4 WC Physics, Multidisciplinary SC Physics GA 140QF UT WOS:000077099300037 ER PT J AU Schwegler, E Challacombe, M Head-Gordon, M AF Schwegler, E Challacombe, M Head-Gordon, M TI A multipole acceptability criterion for electronic structure theory SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAUSSIAN-BASIS FUNCTIONS; LINEAR SCALING COMPUTATION; 2-ELECTRON INTEGRALS; RECURRENCE RELATIONS; REPULSION INTEGRALS; MOLECULAR INTEGRALS; ALGORITHM; MATRIX; SYSTEMS; TENSOR AB Accurate and computationally inexpensive estimates of multipole expansion errors are crucial to the success of several fast electronic structure methods. In this paper, a new nonempirical multipole acceptability criterion is described that is directly applicable to expansions of high order moments. Several model calculations typical of electronic structure theory are presented to demonstrate its performance. For cases involving small translation distances, accuracies are increased by up to five orders of magnitude over an empirical criterion. The new multipole acceptance criterion is on average within an order of magnitude of the exact: expansion error. Use of the multipole acceptance criterion in hierarchical multipole based methods as well as in traditional electronic structure methods is discussed. (C) 1998 American Institute of Physics. [S0021-9606(98)30844-2]. C1 Univ Calif Los Alamos Natl Lab, Theoret Chem Div, Los Alamos, NM 87545 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Challacombe, M (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Chem Div, POB 1663, Los Alamos, NM 87545 USA. EM mchalla@t12.lanl.gov RI Schwegler, Eric/F-7294-2010; Schwegler, Eric/A-2436-2016 OI Schwegler, Eric/0000-0003-3635-7418 NR 50 TC 23 Z9 23 U1 0 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 NOV 22 PY 1998 VL 109 IS 20 BP 8764 EP 8769 DI 10.1063/1.477546 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 139QE UT WOS:000077039900006 ER PT J AU Gomez, MA Pratt, LR AF Gomez, MA Pratt, LR TI Construction of simulation wave functions for aqueous species: D3O+ SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; CENTRAL FORCE MODEL; QUANTUM MONTE-CARLO; IONIC DISSOCIATION PRODUCTS; LIQUID WATER; INTRAMOLECULAR DEGREES; SUPERCRITICAL WATER; FLEXIBLE BJH; STATES; POTENTIALS AB This paper investigates Monte Carlo techniques for construction of compact wave functions for the internal atomic motion of the D3O+ ion. The polarization force field models of Stillinger et al. and of Ojamae et al. were used. Initial pair product wave functions were obtained from the asymptotic high temperature many-body density matrix after contraction to atom pairs using Metropolis Monte Carlo. Subsequent characterization shows these pair product wave functions to be well optimized for atom pair correlations despite that fact that the predicted zero point energies are too high. The pair product wave functions are suitable to use within variational Monte Carlo, including excited states, and density matrix Monte Carlo calculations. Together with the pair product wave functions, the traditional variational theorem permits identification of wave function features with significant potential for further optimization. The most important explicit correlation variable found for the D3O+ ion was the vector triple product r(OD1) . (r(OD2) X r(OD3)). Variational Monte Carlo with 9 of such explicitly correlated functions yielded a ground state wave function with an error of 5-6% in the zero point energy. (C) 1998 American Institute of Physics. [S0021-9606(98)51144-0]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gomez, MA (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM gomez@lanl.gov RI Pratt, Lawrence/H-7955-2012 OI Pratt, Lawrence/0000-0003-2351-7451 NR 47 TC 7 Z9 7 U1 1 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 NOV 22 PY 1998 VL 109 IS 20 BP 8783 EP 8789 DI 10.1063/1.477548 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 139QE UT WOS:000077039900008 ER PT J AU Peterson, KA AF Peterson, KA TI Accurate ab initio near-equilibrium potential energy and dipole moment functions of the X B-2(1) and first excited (2)A(2) electronic states of OClO and OBrO SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; CORRELATED MOLECULAR CALCULATIONS; RO-VIBRATIONAL SPECTRA; GAUSSIAN-BASIS SETS; CHLORINE DIOXIDE; STRATOSPHERIC OZONE; ABSORPTION-SPECTRUM; INFRARED-SPECTRUM; BROMINE DIOXIDES; WAVE-FUNCTIONS AB Using highly correlated multireference configuration interaction wave functions with large correlation consistent basis sets, three-dimensional near-equilibrium potential energy functions (PEFs) have been calculated for the X B-2(1) and first excited (2)A(2) electronic states of the atmospherically important OClO and OBrO radicals. The analytical PEFs have been used in perturbational and variational calculations of the anharmonic spectroscopic constants and vibrational spectra of both species. Excellent agreement with the available experimental data are observed for both species and electronic states, e.g., the vibrational fundamental frequencies in the ground electronic states are reproduced to within about 5 cm(-1). For the A (2)A(2) state of OClO, it is demonstrated that the anomolously strong intensity of the nu(3) mode in the UV absorption spectrum is due to strong anharmonic coupling between the stretching vibrations and not to a double minimum in the potential. Three-dimensional electric dipole moment functions have also been calculated for the ground electronic states of both species. These were used to calculate accurate absolute infrared absorption intensities for the fundamentals and low-lying overtones and combination bands of both species. (C) 1998 American Institute of Physics. [S0021-9606(98)30144-0]. C1 Washington State Univ, Dept Chem, Richland, WA 99352 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Peterson, KA (reprint author), Washington State Univ, Dept Chem, 2710 Univ Dr, Richland, WA 99352 USA. NR 63 TC 71 Z9 71 U1 0 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 NOV 22 PY 1998 VL 109 IS 20 BP 8864 EP 8875 DI 10.1063/1.477558 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 139QE UT WOS:000077039900018 ER PT J AU Monteiro, OR Vizir, A Brown, G AF Monteiro, OR Vizir, A Brown, G TI Multilayer thin-films with chevron-like microstructure SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID COBALT FILMS; TOPOGRAPHY; ANISOTROPY; COATINGS; TEXTURE; GROWTH AB Direct current magnetron sputtering and evaporation have been used to form thin films with a columnar structure having a chevron-like morphology. This type of morphology is one of the possible types present in sculptured thin films. The tilt angle of the columnar grains was controlled by variation of the angle of incidence of the depositing species, and by carrying out the deposition at a number of different angles of incidence films having a chevron-like microstructure were formed. Films of copper, aluminium and alumina were produced by the technique described here, it is demonstrated that under certain conditions it is possible to grow films that are virtually free of renucleation at the planes where the atom flux changes direction (kink planes). The morphology of the individual grains in the chevron-like films agrees with the zone model developed for more conventional films. The chevron structures were also quite visible in amorphous films, and in this case the 'grain boundaries' consist of regions of lower density. A few examples of potential applications for these chevron films are discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634050, Russia. RP Monteiro, OR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 53-004, Berkeley, CA 94720 USA. EM ormonteiro@lbl.gov RI Vizir, Alexey/R-2139-2016 OI Vizir, Alexey/0000-0002-9563-8650 NR 25 TC 20 Z9 20 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD NOV 21 PY 1998 VL 31 IS 22 BP 3188 EP 3196 DI 10.1088/0022-3727/31/22/003 PG 9 WC Physics, Applied SC Physics GA 145XE UT WOS:000077397000003 ER PT J AU Markovic, NM Grgur, BN Lucas, CA Ross, PN AF Markovic, NM Grgur, BN Lucas, CA Ross, PN TI Underpotential deposition of lead onto Pt(100) in acid solutions: Adsorption isotherms and interface structures SO JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS LA English DT Article ID BROMIDE ADSORPTION; AUGER-SPECTROSCOPY; DISK ELECTRODE; PT(111); LEED; PLATINUM(111); CHLORIDE; COPPER; SITU AB The underpotential deposition (UPD) of Pb onto Pt(100) in pure perchloric acid and in solution containing Br- was examined by classical rotating ring disk electrode (RRDPt(100)E) electrochemical methods in combination with in-situ surface X-ray scattering measurements. The total amount of Pb deposited underpotentially in 0.1 M HClO4 is approximate to 0.62 +/- 5% ML (1 ML equals 1 Pb atom per Pt surface atom), nearly equivalent to a close-packed monolayer of fully discharged Pb adatoms, e.g. 0.63 ML. In pure perchloric acid, deposition of Pb adatoms is accompanied by complete displacement of OHad from the Pt(100) surface, and in the potential range 0.15 V < E < 0.35 V we found an ordered surface structure with a c(2 x 2) unit cell. In perchloric acid containing bromide, the maximum Pb-upd surface coverage is approximate to 0.5 ML; the deposition of 0.5 ML of Pb adatoms is accompanied by desorption of about 0.22 ML of the Br-ad adsorbed on the Pt surface at 0.6 V (ca. 0.42 ML). Thus, Pb UPD on Pt(100) from solution containing Br- is a competitive process, with the total amount of Pb deposited at underpotential being less than the amount needed to form a close-packed monolayer. As a consequence, the formation of an ordered c(2 x 2) structure is observed only at E < 0.15 V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Liverpool, Dept Phys, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. RP Markovic, NM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. OI Grgur, Branimir/0000-0003-4684-9053; Lucas, Christopher/0000-0001-5743-3868 NR 16 TC 14 Z9 14 U1 0 U2 6 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 0956-5000 J9 J CHEM SOC FARADAY T JI J. Chem. Soc.-Faraday Trans. PD NOV 21 PY 1998 VL 94 IS 22 BP 3373 EP 3379 DI 10.1039/a804620d PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 140HW UT WOS:000077082700012 ER PT J AU Chen, KC Ford, RM Cummings, PT AF Chen, KC Ford, RM Cummings, PT TI The global turning probability density function for motile bacteria and its applications SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID CHEMOTACTIC CELL-POPULATIONS; ESCHERICHIA-COLI; MODELS; MIGRATION; BEHAVIOR AB The angular turning probability density distribution for motile bacteria is usually measured in local coordinates and is therefore inconvenient for global analyses of the chemotactic bacterial migration. In this paper we present analytical derivations that convert the local angular turning probability density distribution into a global one. The explicit expression of a reduced global turning probability density function for motile bacteria was derived and its relevant properties were investigated. Depending on the angle variable being integrated and the integration range, three types of cosine moments were separately defined and studied. Some statistical indices and parameters such as the directional persistence, persistence number, and one-dimensional reversal probability were found to be embedded in the various moments of the reduced global turning probability density function. Applications of the reduced global turning probability and its integrated moments to a three-dimensional cell balance equation in an axisymmetric system were also discussed. (C) 1998 Academic Press. C1 Univ Virginia, Dept Chem Engn, Charlottesville, VA 22903 USA. Univ Tennessee, Dept Chem Engn, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Chen, KC (reprint author), NYU, Med Ctr, Dept Physiol & Neurosci, 550 1st Ave, New York, NY 10016 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 29 TC 6 Z9 6 U1 0 U2 2 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD NOV 21 PY 1998 VL 195 IS 2 BP 139 EP 155 DI 10.1006/jtbi.1998.0768 PG 17 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 140GL UT WOS:000077079200001 PM 9822560 ER PT J AU Wolf, DM Eeckman, FH AF Wolf, DM Eeckman, FH TI On the relationship between genomic regulatory element organization and gene regulatory dynamics SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID BACTERIOPHAGE-LAMBDA; CONTROL-SYSTEM; NETWORKS; MODEL; COOPERATIVITY; BEHAVIOR AB In this project we study the relationship between genomic regulatory element organization and gene regulatory dynamics. This paper illustrates an approach to investigating this relationship based on the application of classical nonlinear system analysis techniques to a transcription level, statistical thermodynamical model like that used in Shea & Ackers (1985). Preliminary ideas presented at the ICMCM conference (Wolf & Eeckman, 1998) are developed in this manuscript. We show that, for prokaryotic gene circuits dominated by local promoter control, dynamical system behavior descriptors like the number and stability of equilibrium point steady states and their bifurcation potential can be largely determined from genomic organization (e.g: the number, type, and placement of regulatory protein binding sites). Concepts are illustrated on hypothetical gene regulation systems with one or two genes and varying numbers of regulatory protein binding sites (operators). Gene regulatory systems with a single gene and an arbitrary number of operator sites are shown to be globally stable, with the potential for having multiple equilibrium points and capable of bifurcating. A monomer-controlled gene regulation system with n operator sites is proven to have a maximum of 1 + n/2 stable equilibria for even n, and (n + 1)/2 for odd n, while a multimer-controlled, n operator site system is shown to have a maximum of 2 + n/2 stable equilibria for even n, and (n + 3)/2 for odd n. These results are applied to the design of a two-state switch using a gene regulation system with two operator sites. The question "what is the simplest possible gene regulation system capable of acting like a switch?" is answered. The paper ends with an analysis of a two-gene regulation system, the results of which point to the existence of a "soft-switching" mechanism that may account for the "on-off" hypothesized behavior of some gene networks. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Bioinformat Grp, Berkeley, CA 94720 USA. GeneNetworks, Alameda, CA 94502 USA. RP Wolf, DM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, NERSC, Bioinformat Grp, MS 1123,1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 20 TC 82 Z9 83 U1 1 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD NOV 21 PY 1998 VL 195 IS 2 BP 167 EP 186 DI 10.1006/jtbi.1998.0790 PG 20 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA 140GL UT WOS:000077079200003 PM 9822562 ER PT J AU Benjamin, D AF Benjamin, D TI SVX-II beam test results SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Vertex Detectors CY AUG 31-SEP 05, 1997 CL MANGARATIBA, BRAZIL SP Brazilian Res Council (CNPq), FAPERJ AB This paper presents the first results from the FNAL Meson test beam using SVX-II prototype detectors, taken at the MT-6 beam at FNAL. The signal size for double-sided double-metal detectors, as a function of radiation dose, is presented. The detectors were irradiated with 8 GeV/c proton beam at FNAL. The first results for detectors made from 6 in wafers is also given here. There is no decrease in signal size in the irradiated detectors with radiation doses up to 1.3 Mrad. The detectors made from 6 in wafers have comparable performance to detectors made from 4 in wafers. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Texas Tech Univ, Dept Phys, Lubbock, TX 79409 USA. RP Benjamin, D (reprint author), Fermi Natl Accelerator Lab, MS 318,POB 500, Batavia, IL 60510 USA. NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 1998 VL 418 IS 1 BP 80 EP 84 DI 10.1016/S0168-9002(98)00719-0 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UM UT WOS:000077218800011 ER PT J AU Lipton, R AF Lipton, R TI The D0 silicon tracker SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Vertex Detectors CY AUG 31-SEP 05, 1997 CL MANGARATIBA, BRAZIL SP Brazilian Res Council (CNPq), FAPERJ AB A 800 000 channel Silicon Tracker is being constructed as a part of the DO Upgrade at Fermilab. We describe the design of the tracking system and detectors. Results are presented for production tests of radiation hard SVX-IIE chips and mechanical support structures. Techniques for ladder and disk production and testing are also presented. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Lipton, R (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 4 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 1998 VL 418 IS 1 BP 85 EP 90 DI 10.1016/S0168-9002(98)00720-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UM UT WOS:000077218800012 ER PT J AU Roco, MTP AF Roco, MTP TI Results from the D0 silicon vertex detector beam tests SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Vertex Detectors CY AUG 31-SEP 05, 1997 CL MANGARATIBA, BRAZIL SP Brazilian Res Council (CNPq), FAPERJ AB Extensive tests of the DO silicon vertex detectors and the final version of the SVX-II chip and readout electronics were performed at a test beam facility equipped with a 2T magnet at FNAL. Preliminary results are reported on the performance of the SVX-II chip, charge collection properties, signal to noise ratio, cluster pulse height and spatial resolution. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Roco, MTP (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 2 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 NOV 21 PY 1998 VL 418 IS 1 BP 91 EP 96 DI 10.1016/S0168-9002(98)00721-9 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UM UT WOS:000077218800013 ER PT J AU Krammer, M Adam, W Bauer, C Berdermann, E Bogani, F Borchi, E Bruzzi, M Colledani, C Conway, J Dabrowski, W Delpierre, P Deneuville, A Dulinski, W van Eijk, B Fallou, A Fish, D Foulon, F Friedl, M Gan, KK Gheeraert, E Grigoriev, E Hallewell, G Hall-Wilton, R Han, S Hartjes, F Hrubec, J Husson, D Kagan, H Kania, D Kaplon, J Kass, R Knopfle, KT Manfredi, PF Meier, D Mishina, M LeNormand, F Pan, LS Pernegger, H Pernicka, M Re, V Riester, GL Roe, S Roff, D Rudge, A Schnetzer, S Sciortino, S Speziali, V Stelzer, H Stone, R Tapper, RJ Tesarek, R Thomson, GB Trawick, M Trischuk, W Turchetta, R Walsh, AM Wedenig, R Weilhammer, P Ziock, H Zoeller, M AF Krammer, M Adam, W Bauer, C Berdermann, E Bogani, F Borchi, E Bruzzi, M Colledani, C Conway, J Dabrowski, W Delpierre, P Deneuville, A Dulinski, W van Eijk, B Fallou, A Fish, D Foulon, F Friedl, M Gan, KK Gheeraert, E Grigoriev, E Hallewell, G Hall-Wilton, R Han, S Hartjes, F Hrubec, J Husson, D Kagan, H Kania, D Kaplon, J Kass, R Knopfle, KT Manfredi, PF Meier, D Mishina, M LeNormand, F Pan, LS Pernegger, H Pernicka, M Re, V Riester, GL Roe, S Roff, D Rudge, A Schnetzer, S Sciortino, S Speziali, V Stelzer, H Stone, R Tapper, RJ Tesarek, R Thomson, GB Trawick, M Trischuk, W Turchetta, R Walsh, AM Wedenig, R Weilhammer, P Ziock, H Zoeller, M TI Status of diamond particle detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 6th International Workshop on Vertex Detectors CY AUG 31-SEP 05, 1997 CL MANGARATIBA, BRAZIL SP Brazilian Res Council (CNPq), FAPERJ AB To continue the exciting research in the field of particle physics new accelerators and experiments are under construction. In some of these experiments, e.g. ATLAS and CMS at the Large Hadron Collider at CERN or HERA-B at DESY, the detectors have to withstand an extreme environment. The detectors must be radiation hard, provide a very fast signal, and be as thin as possible. The properties of CVD diamond allow to fulfill these requirements and make it an ideal material for the detectors close to the interaction region of these experiments, i.e. the vertex detectors or the inner trackers. The RD42 collaboration is developing diamond detectors for these applications. The program of RD42 includes the improvement of the charge collection properties of CVD diamond, the study of the radiation hardness and the development of low-noise radiation hard readout electronics. An overview of the progress achieved during the last years will be given. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Austrian Acad Sci, Inst Hochenergiephys, A-1050 Vienna, Austria. Max Planck Inst Kernphys, D-69029 Heidelberg, Germany. GSI Darmstadt, D-6100 Darmstadt, Germany. LENS, Florence, Italy. Univ Florence, Florence, Italy. Ctr Rech Nucl, LEPSI, F-67037 Strasbourg, France. Rutgers State Univ, Piscataway, NJ 08855 USA. CERN, CH-1211 Geneva 23, Switzerland. CPPM, F-13288 Marseille, France. LEPES, Grenoble, France. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Ctr Etud Saclay, F-91191 Gif Sur Yvette, France. Ohio State Univ, Columbus, OH 43210 USA. Univ Bristol, Bristol BS8 1TL, Avon, England. Univ Calif Los Alamos Natl Lab, Div Res, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Pavia, Dipartimento Elettron, I-27100 Pavia, Italy. FNAL, Batavia, IL USA. Sandia Natl Labs, Livermore, CA 94550 USA. Univ Toronto, Toronto, ON M5S 1A7, Canada. RP Krammer, M (reprint author), Austrian Acad Sci, Inst Hochenergiephys, Nikolsdorferg 18, A-1050 Vienna, Austria. RI Krammer, Manfred/A-6508-2010; Grigoriev, Eugene/K-6650-2013; Bruzzi, Mara/K-1326-2015; Gheeraert, Etienne/E-8071-2015; OI Krammer, Manfred/0000-0003-2257-7751; Grigoriev, Eugene/0000-0001-7235-9715; Bruzzi, Mara/0000-0001-7344-8365; Gheeraert, Etienne/0000-0002-9952-5805; Re, Valerio/0000-0003-0697-3420; Sciortino, Silvio/0000-0003-0570-7489 NR 6 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 21 PY 1998 VL 418 IS 1 BP 196 EP 202 DI 10.1016/S0168-9002(98)00733-5 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 142UM UT WOS:000077218800024 ER PT J AU De Arellano-Lopez, AR Dominguez-Rodriguez, A Routbort, JL AF De Arellano-Lopez, AR Dominguez-Rodriguez, A Routbort, JL TI Microstructural constraints for creep in SiC-whisker-reinforced Al2O3 SO ACTA MATERIALIA LA English DT Article ID SILICON-CARBIDE; PLASTIC-DEFORMATION; MATRIX COMPOSITES; ALUMINA; CERAMICS; BEHAVIOR; FLOW; MECHANISMS AB New and published creep data obtained on a SiC-whisker-reinforced Al2O3 composite have been analyzed in terms of an effective grain size and a threshold/critical stress, These concepts allow the formation of a consistent picture of the high-temperature deformation of these composites. For low volume fractions of whiskers, before the formation of a point-contact percolative limit is reached, deformation proceeds via grain-boundary sliding after the applied stress exceeds a temperature-dependent threshold stress. In this regime, the nominal grain size is the most important microstructural feature. For larger volume fractions of whiskers, up to the critical volume fraction for formation of facet-to-facet contact, whiskers inhibit grain-boundary sliding and deformation proceeds by means of pure diffusion. In this regime, the most important microstructural feature is an effective grain size, i.e. the spacing between the whiskers. Deformation proceeds until the stress reaches a temperature-dependent critical stress. At this point, damage occurs by unaccommodated grain-boundary sliding and creep is no longer in a steady state. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Sevilla, Dept Fis Mat Condensada, E-41080 Seville, Spain. Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP De Arellano-Lopez, AR (reprint author), Univ Sevilla, Dept Fis Mat Condensada, E-41080 Seville, Spain. OI R. de Arellano Lopez, Antonio/0000-0002-7443-0244; Dominguez-Rodriguez, Arturo/0000-0003-1598-5669 NR 30 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 20 PY 1998 VL 46 IS 18 BP 6361 EP 6373 DI 10.1016/S1359-6454(98)00331-0 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 148TA UT WOS:000077547600005 ER PT J AU Kriese, MD Moody, NR Gerberich, WW AF Kriese, MD Moody, NR Gerberich, WW TI Effects of annealing and interlayers on the adhesion energy of copper thin films to SiO2/Si substrates SO ACTA MATERIALIA LA English DT Article ID FRACTURE ENERGY; DELAMINATION; MICROSCRATCH; DIELECTRICS; INDENTATION; INTERFACES; MECHANICS; ADHERENCE; HARDNESS; SILICON AB The adhesion of sputtered copper thin films was measured with a quantitative indentation technique utilizing refractory superlayers to trigger and promote delamination. Adhesion energies of the indentation-induced delaminations were analyzed in terms of the critical strain energy release rate. Two groups of films were investigated. Group I ranged in thickness from 225 to 1000 nm in both the as-deposited and annealed condition. Adhesion enemies ranged from 2 to 15 J/m(2), with higher adhesion for the annealed condition. Group II films had nominal thicknesses of 430 and 1100 nm, some with 7-10 nm interlayers of either titanium or chromium. Adhesion energies of these films ranged from 4 to 30 J/m(2), increasing by a factor from 1.3 to 7.5, as a function of the interlayer presence and type with the increase in energy due to a chromium interlayer exceeding that of titanium. Adhesion energies increased with film thickness for all films, with interlayers and annealing producing a larger increase. These quantitative results were compared to previous semi-quantitative and quantitative results, and shown to have comparable magnitudes and trends. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Sandia Natl Labs, Livermore, CA 94551 USA. Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. RP Gerberich, WW (reprint author), Univ Minnesota, Dept Chem Engn & Mat Sci, Minneapolis, MN 55455 USA. NR 35 TC 58 Z9 58 U1 3 U2 17 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 20 PY 1998 VL 46 IS 18 BP 6623 EP 6630 DI 10.1016/S1359-6454(98)00277-8 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 148TA UT WOS:000077547600029 ER PT J AU Se-Thoe, SY Foley, BT Chan, SY Lin, RVTP Oh, HML Ling, AE Chew, SK Snodgrass, I Sng, JEH AF Se-Thoe, SY Foley, BT Chan, SY Lin, RVTP Oh, HML Ling, AE Chew, SK Snodgrass, I Sng, JEH TI Analysis of sequence diversity in the C2-V3 regions of the external glycoproteins of HIV type 1 in Singapore SO AIDS RESEARCH AND HUMAN RETROVIRUSES LA English DT Article ID SUBTYPE-E; TRANSMISSION; SENSITIVITY; ANTIBODIES; INFECTION; THAILAND C1 Singapore Gen Hosp, Dept Pathol, Singapore 169608, Singapore. Los Alamos Natl Lab, Los Alamos, NM USA. Singapore Gen Hosp, Clin Trial & Epidemiol Res Unit, Singapore 169608, Singapore. New Changi Hosp, Singapore 529889, Singapore. Minist Hlth, Dept Epidemiol & Dis Control, Singapore 169608, Singapore. Tan Tock Seng Hosp, Dept Clin Epidemiol, Singapore 308433, Singapore. RP Lin, RVTP (reprint author), Singapore Gen Hosp, Dept Pathol, Outram Rd, Singapore 169608, Singapore. OI Foley, Brian/0000-0002-1086-0296 NR 18 TC 4 Z9 4 U1 0 U2 0 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 USA SN 0889-2229 J9 AIDS RES HUM RETROV JI Aids Res. Hum. Retrovir. PD NOV 20 PY 1998 VL 14 IS 17 BP 1601 EP 1604 DI 10.1089/aid.1998.14.1601 PG 4 WC Immunology; Infectious Diseases; Virology SC Immunology; Infectious Diseases; Virology GA 141XD UT WOS:000077168800012 PM 9840294 ER PT J AU Hauser, MG Arendt, RG Kelsall, T Dwek, E Odegard, N Weiland, JL Freudenreich, HT Reach, WT Silverberg, RF Moseley, SH Pei, YC Lubin, P Mather, JC Shafer, RA Smoot, GF Weiss, R Wilkinson, DT Wright, EL AF Hauser, MG Arendt, RG Kelsall, T Dwek, E Odegard, N Weiland, JL Freudenreich, HT Reach, WT Silverberg, RF Moseley, SH Pei, YC Lubin, P Mather, JC Shafer, RA Smoot, GF Weiss, R Wilkinson, DT Wright, EL TI The COBE Diffuse Infrared Background Experiment search for the cosmic infrared background. I. Limits and detections SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmology : observations; diffuse radiation; infrared : general ID ROCKET-BORNE OBSERVATION; GAMMA-RAYS; DIRBE MAPS; SKY; RADIATION; SPECTRUM; ANISOTROPY; GALAXIES; MODEL; LIGHT AB The Diffuse Infrared Background Experiment (DIRBE) on the Cosmic Background Explorer (COBE) spacecraft was designed primarily to conduct a systematic search for an isotropic cosmic infrared background (CIB) in 10 photometric bands from 1.25 to 240 mu m. The results of that search are presented here. Conservative limits on the CIB are obtained from the minimum observed brightness in all-sky maps at each wavelength, with the faintest limits in the DIRBE spectral range being at 3.5 mu m (vI(v) < 64 nW m(-2) sr(-1), 95% confidence level) and at 240 mu m (vI(v) < 28 nW m(-2) sr(-1), 95% confidence level). The bright foregrounds from interplanetary dust scattering and emission, stars, and interstellar dust emission are the principal impediments to the DIRBE measurements of the GIB. These foregrounds have been modeled and removed from the sky maps. Assessment of the random and systematic uncertainties in the residuals and tests for isotropy show that only the 140 and 240 mu m data provide candidate detections of the GIB. The residuals and their uncertainties provide CIB upper limits more restrictive than the dark sky limits at wavelengths from 1.25 to 100 mu m. No plausible solar system or Galactic source of the observed 140 and 240 mu m residuals can be identified, leading to the conclusion that the CIB has been detected at levels of vI(v) = 25 +/- 7 and 14 +/- 3 nW m(-2) sr(-1) at 140 and 240 mu m, respectively. The integrated energy from 140 to 240 mu m, 10.3 nW m(-2) sr(-1), is about twice the integrated optical light from the galaxies in the Hubble Deep Field, suggesting that star formation might have been heavily enshrouded by dust at high redshift. The detections and upper limits reported here provide new constraints on models of the history of energy-releasing processes and dust production since the decoupling of the cosmic microwave background from matter. C1 Space Telescope Sci Inst, Baltimore, MD 21218 USA. NASA, Goddard Space Flight Ctr, Rayetheon STX, Greenbelt, MD 20771 USA. CALTECH, Jet Prop Lab, IPAC, Pasadena, CA 91125 USA. Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Phys, Space Sci Lab, Berkeley, CA 94720 USA. MIT, Dept Phys, Cambridge, MA 02139 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Univ Calif Los Angeles, Dept Astron, Los Angeles, CA 90024 USA. RP Hauser, MG (reprint author), Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA. RI Reach, William/C-4710-2008; Moseley, Harvey/D-5069-2012; Dwek, Eli/C-3995-2012; OI Reach, William/0000-0001-8362-4094 NR 60 TC 540 Z9 542 U1 1 U2 9 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1998 VL 508 IS 1 BP 25 EP 43 DI 10.1086/306379 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152LX UT WOS:000077780000004 ER PT J AU Zygelman, B Stancil, PC Dalgarno, A AF Zygelman, B Stancil, PC Dalgarno, A TI Stimulated radiative association of He and H+ SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic processes; early universe; molecular processes; planetary nebulae : general; quasars : general ID AB-INITIO; EMISSION AB The enhancement of the rate coefficient for the radiative association of He and H+ to form HeH+ arising from stimulated emission due to a blackbody radiation held is calculated. The effects on the fractional abundance of HeH+ in the early universe, in supernova ejecta, and in planetary nebulae are small. There may occur some enhancement in the abundance of HeH+ in quasar broad-line clouds. C1 Univ Nevada, Dept Phys, WM Keck Lab Computat Phys, Las Vegas, NV 89154 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Harvard Smithsonian Ctr Astrophys, Cambridge, MA 02138 USA. RP Zygelman, B (reprint author), Univ Nevada, Dept Phys, WM Keck Lab Computat Phys, Las Vegas, NV 89154 USA. NR 21 TC 44 Z9 44 U1 0 U2 6 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 20 PY 1998 VL 508 IS 1 BP 151 EP 156 DI 10.1086/306399 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152LX UT WOS:000077780000012 ER PT J AU Qin, KC AF Qin, KC TI Measuring the true helicity of carbon nanotubes SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MICROTUBULES; DIFFRACTION; GROWTH; ROPES AB Electron diffraction patterns from carbon nanotubes have been analyzed for measuring the true helicity of carbon nanotubes. The cylindrical curvature of the tubules causes a large difference between the apparent half twist angle which appears in electron diffraction patterns and the true helical angle of the examined tubule. A direct method has been developed to calculate the cylindrical correction factors, which are vital for accurate deduction of the true helicity from electron diffraction patterns. By combining with measured diameters from real-space images, it is now possible to determine the atomic structure of carbon nanotubes. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Qin, KC (reprint author), IBM Corp, Dept MXQ014, 5600 Cottle Rd, San Jose, CA 95193 USA. NR 14 TC 21 Z9 21 U1 0 U2 1 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 NOV 20 PY 1998 VL 297 IS 1-2 BP 23 EP 28 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 140UW UT WOS:000077107600004 ER PT J AU Taylor, TR Asmis, KR Xu, CS Neumark, DM AF Taylor, TR Asmis, KR Xu, CS Neumark, DM TI Evolution of electronic structure as a function of size in gallium phosphide semiconductor clusters SO CHEMICAL PHYSICS LETTERS LA English DT Article ID KINETIC-ENERGY SPECTROSCOPY; PHOTOELECTRON-SPECTROSCOPY; SILICON; ANIONS; STATES; SPECTRA; PHOTODETACHMENT; CHEMISTRY; GERMANIUM; PARTICLES AB Anion photoelectron spectra have been taken of GaxPy- clusters at a photoderachment wavelength of 266 nm (4.657 eV). Clusters of varying stoichiometry with up to 18 atoms have been investigated. We obtain electron affinities and vertical detachment energies to the ground and low-lying excited states of the neutral clusters, Photoelectron spectra of clusters with 3-5 atoms are compared to previously reported ab initio calculations. Trends in the electron affinities and excitation energies for the larger clusters are discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM dan@radon.cchem.berkeley.edu RI Asmis, Knut/N-5408-2014; Neumark, Daniel/B-9551-2009 OI Asmis, Knut/0000-0001-6297-5856; Neumark, Daniel/0000-0002-3762-9473 NR 35 TC 84 Z9 88 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 EI 1873-4448 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD NOV 20 PY 1998 VL 297 IS 1-2 BP 133 EP 140 DI 10.1016/S0009-2614(98)01104-X PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 140UW UT WOS:000077107600020 ER PT J AU Yarema, KJ Mahal, LK Bruehl, RE Rodriguez, EC Bertozzi, CR AF Yarema, KJ Mahal, LK Bruehl, RE Rodriguez, EC Bertozzi, CR TI Metabolic delivery of ketone groups to sialic acid residues - Application to cell surface glycoform engineering SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID N-ACETYLNEURAMINIC ACID; SELECTIN-CARBOHYDRATE INTERACTIONS; O-GLYCANS; MAMMALIAN-CELLS; RAT-LIVER; OLIGOSACCHARIDES; ACETYLMANNOSAMINE; BIOSYNTHESIS; GLYCOSYLTRANSFERASE; GLYCOPROTEIN AB The development of chemical strategies for decorating cells with defined carbohydrate epitopes would greatly facilitate studies of carbohydrate-mediated cell surface interactions. This report describes a general strategy for engineering the display of chemically defined oligosaccharides on cell surfaces that combines the concepts of metabolic engineering and selective chemical reactivity, Using a recently described method (Mahal, L, K., Yarema, K. J., and Bertozzi, C, R. (1997) Science 276, 1125-1128), we delivered a uniquely reactive ketone group to endogenous cell surface sialic acid residues by treating cells with the ketone-bearing metabolic precursor N-levulinoylmannosamine (ManLev), The ketone undergoes highly selective condensation reactions with complementary nucleophiles such as aminooxy and hydrazide groups. The detailed quantitative parameters of ManLev metabolism in human and nonhuman-derived cell lines were determined to establish a foundation for the modification of cell surfaces with novel epitopes at defined cell-surface densities. Ketones within the glycoconjugates on ManLev-treated cells were then reacted with synthetic aminooxy and hydrazide-functionalized carbohydrates, The remodeled cells were endowed with novel lectin binding profiles as determined by flow cytometry analysis. The simplicity and generality of this method make it well suited for use in the study of carbohydrate-mediated cell surface interactions. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Bertozzi, CR (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 71 TC 126 Z9 128 U1 0 U2 19 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD NOV 20 PY 1998 VL 273 IS 47 BP 31168 EP 31179 DI 10.1074/jbc.273.47.31168 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 141HG UT WOS:000077136900049 PM 9813021 ER PT J AU Shalliker, RA Broyles, BS Guiochon, G AF Shalliker, RA Broyles, BS Guiochon, G TI Visualization of solute migration in liquid chromatography columns SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE detection, LC; visualization of solute migration; solute migration ID RADIAL-DISTRIBUTION; FLOW VELOCITY; EFFICIENCY; HOMOGENEITY; DISPERSION; BEDS AB By matching the refractive indices of the mobile phase, the stationary phase and the material of the bed enclosure, one can render transparent to the eye the chromatographic column which is normally opaque in nature. As a result, band visualization is readily obtained. High-definition on-column detection becomes feasible by using a photographic detector instead of the conventional post-column, on-line (UV-Vis or similar) detector. Quantitative information regarding the concentration distribution in the band is obtained by utilizing optical scanners to obtain a digital image and computer imaging software. The processes of data collection and image analysis are discussed in detail and are illustrated by observing the concept of the infinite diameter column following a central point injection. The performance of the photographic detection method is compared to that of regular detection procedures. The efficiency of the column was determined with both on-column measurements and regular post-column measurements. A minimum reduced plate height (h) of 1.9 was recorded with post-column detection, in agreement with the average of the results given by on column detection. On-column analysis allowed the determination of the local plate height which was found to vary across the central region of the column between 2.7 and 0.95. (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. RP Guiochon, G (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 22 TC 27 Z9 27 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD NOV 20 PY 1998 VL 826 IS 1 BP 1 EP 13 DI 10.1016/S0021-9673(98)00734-1 PG 13 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA 142PR UT WOS:000077209600001 ER PT J AU Kupferman, R AF Kupferman, R TI Simulation of viscoelastic fluids: Couette-Taylor flow SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE viscoelastic flow; Couette-Taylor; finite differences; Hopf bifurcation ID HYPERBOLIC CONSERVATION-LAWS; INSTABILITY; SCHEMES; RESOLUTION; EQUATIONS AB We present a numerical scheme for viscoelastic flow based on a second-order central differencing method recently introduced in the context of incompressible newtonian flow; the incompressibility constraint is treated with the projection method. The result is a simple and efficient scheme that is readily adaptable to a wide class of differential constitutive equations and flow geometries. We implement the new method on Couette-Taylor how for a fluid governed by the Oldroyd-B constitutive equations. We simulate transient flow in a domain that includes at least eight wavelengths during many hundreds of natural periods. For weak elasticity, a stationary instability leading to Taylor vortices is observed. For a regime of parameters where both inertia and elasticity are important, the instability is oscillatory. In both cases the early stage growth rates are compared to linear stability calculations, showing good agreement. The oscillatory instability is fourfold degenerate and gives rise to two bifurcating branches: an axially traveling wave and a standing wave; only one of these solutions is stable. In the early stages of the instability, there is generally a combination of traveling and standing waves, depending on the initial conditions. As nonlinearities become important, the flow spontaneously breaks into coexisting regions of upward- and downward-going waves. Such flow can persist for long times, until the globally stable traveling wave takes over and a limit cycle is reached. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Math, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Math, 1 Cyclotron Rd,50A-2152, Berkeley, CA 94720 USA. EM raz@math.lbl.gov NR 35 TC 16 Z9 17 U1 0 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 NOV 20 PY 1998 VL 147 IS 1 BP 22 EP 59 DI 10.1006/jcph.1998.5934 PG 38 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 143JW UT WOS:000077252900002 ER PT J AU Johansen, H Colella, P AF Johansen, H Colella, P TI A Cartesian grid embedded boundary method for Poisson's equation on irregular domains SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID PARTIAL-DIFFERENTIAL EQUATIONS; ADAPTIVE MESH REFINEMENT; PROJECTION METHOD; COMPUTATION; REGIONS; SOLVER; FLOWS AB We present a numerical method for solving Poisson's equation, with variable coefficients and Dirichlet boundary conditions, on two-dimensional regions. The approach uses a finite-volume discretization, which embeds the domain in a regular Cartesian grid. We treat the solution as a cell-centered quantity, even when those centers are outside the domain. Cells that contain a portion of the domain boundary use conservative differencing of second-order accurate fluxes on each cell volume. The calculation of the boundary flux ensures that the conditioning of the matrix is relatively unaffected by small cell volumes. This allows us to use multigrid iterations with a simple point relaxation strategy. We have combined this with an adaptive mesh refinement (AMR) procedure. We provide evidence that the algorithm is second-order accurate on various exact solutions and compare the adaptive and nonadaptive calculations. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. EO Lawrence Berkeley Natl Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. RP Colella, P (reprint author), Univ Calif Berkeley, Dept Mech Engn, Berkeley, CA 94720 USA. EM pcolella@euler.me.berkeley.edu NR 35 TC 200 Z9 201 U1 2 U2 15 PU ACADEMIC PRESS INC ELSEVIER SCIENCE 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 NOV 20 PY 1998 VL 147 IS 1 BP 60 EP 85 DI 10.1006/jcph.1998.5965 PG 26 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 143JW UT WOS:000077252900003 ER PT J AU Burtsev, S Camassa, R Timofeyev, I AF Burtsev, S Camassa, R Timofeyev, I TI Numerical algorithms for the direct spectral transform with applications to nonlinear Schrodinger type systems SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE nonlinear Schrodinger equation; Zakharov-Shabat eigenvalue problem; nonlinear optics ID SOLITON AB We implement two different algorithms for computing numerically the direct Zakharov-Shabat eigenvalue problem on the infinite line. The first algorithm replaces the potential in the eigenvalue problem by a piecewise-constant approximation, which allows one to solve analytically the corresponding ordinary differential equation. The resulting algorithm is of second order in the step size. The second algorithm uses the fourth-order Runge-Kutta method. We test and compare the performance of these two algorithms on three exactly solvable potentials. We find that even though the Runge-Kutta method is of higher order, this extra accuracy can be lost because of the additional dependence of its numerical error on the eigenvalue. This limits the usefulness of the Runge-Kutta algorithm to a region inside the unit circle around the origin in the complex plane of the eigenvalues, For the computation of the continuous spectrum density, this limitation is particularly severe, as revealed by the spectral decomposition of the L-2-norm of a solution to the nonlinear Schrodinger equation. We show that no such limitations exist for the piecewise-constant algorithm. In particular, this scheme converges uniformly for both continuous and discrete spectrum components. (C) 1998 Academic Press. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Rensselaer Polytech Inst, Dept Math Sci, Troy, NY 12180 USA. RP Timofeyev, I (reprint author), NYU, Courant Inst Math Sci, 251 Mercer St, New York, NY 10012 USA. NR 16 TC 15 Z9 15 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD NOV 20 PY 1998 VL 147 IS 1 BP 166 EP 186 DI 10.1006/jcph.1998.6087 PG 21 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA 143JW UT WOS:000077252900007 ER PT J AU Nunnermacker, LJ Imre, D Daum, PH Kleinman, L Lee, YN Lee, JH Springston, SR Newman, L Weinstein-Lloyd, J Luke, WT Banta, R Alvarez, R Senff, C Sillman, S Holdren, M Keigley, GW Zhou, X AF Nunnermacker, LJ Imre, D Daum, PH Kleinman, L Lee, YN Lee, JH Springston, SR Newman, L Weinstein-Lloyd, J Luke, WT Banta, R Alvarez, R Senff, C Sillman, S Holdren, M Keigley, GW Zhou, X TI Characterization of the Nashville urban plume on July 3 and July 18, 1995 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SOUTHEASTERN UNITED-STATES; GAS-PHASE PEROXIDES; NONENZYMATIC METHOD; CARBONYL-COMPOUNDS; HYDROGEN-PEROXIDE; RURAL SITE; OZONE; NITROGEN; AIRCRAFT; ATLANTA AB This paper reports results from the Southern Oxidants Study field campaign designed to characterize the formation and distribution of ozone and related species in the Nashville urban region, Data from several airborne platforms as well as surface observations on July 3 and 18 are examined to gain insight into the factors that control O-3 formation rates and concentrations in the regional plumes. On both days, well-defined urban and power plant plumes were sampled. Utilizing both aircraft and surface data, a detailed kinetic analysis of the chemical evolution of the urban plume is performed to derive NOx lifetime, ozone production efficiency, OH concentration, HNO3 dry deposition rate, and the relative importance of natural and anthropogenic hydrocarbons to O-3 production. Analysis of the urban plume data revealed a very active photochemical system (average [OH] similar to 1.2 x 10(7) molecules cm(-3)) which consumed 50% of the NOx within approximately 2 hours, at an ozone production efficiency of 2.5 to 4 molecules for each molecule of NOx. Anthropogenic hydrocarbons provided approximately 44% of the fuel for ozone production by the urban plume. The dry deposition rate for HNO3 in the urban plume was estimated to be of the order of 5 to 7 cm s(-1). C1 Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. NOAA, Environm Res Lab, Boulder, CO 80307 USA. Battelle Columbus, Atmospher Sci & Appl Technol, Columbus, OH 43201 USA. NOAA, Air Resources Lab, Silver Spring, MD USA. Univ Michigan, Dept Atmospher Ocean & Space Sci, Ann Arbor, MI 48109 USA. SUNY Coll Old Westbury, Dept Chem Phys, Old Westbury, NY 11568 USA. New York State Dept Hlth, Albany, NY 12201 USA. RP Nunnermacker, LJ (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, POB 5000, Upton, NY 11973 USA. EM lindan@bnl.gov RI Senff, Christoph/I-2592-2013; Banta, Robert/B-8361-2008; Alvarez, Raul/I-4879-2013; Luke, Winston/D-1594-2016; OI Luke, Winston/0000-0002-1993-2241; Sillman, Sanford/0000-0001-6250-1191 NR 38 TC 56 Z9 59 U1 1 U2 9 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 NOV 20 PY 1998 VL 103 IS D21 BP 28129 EP 28148 DI 10.1029/98JD01961 PG 20 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 140GF UT WOS:000077078700011 ER PT J AU Weber, RJ Clarke, AD Litchy, M Li, J Kok, G Schillawski, RD McMurry, PH AF Weber, RJ Clarke, AD Litchy, M Li, J Kok, G Schillawski, RD McMurry, PH TI Spurious aerosol measurements when sampling from aircraft in the vicinity of clouds SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID CONDENSATION NUCLEI; PARTICLE-PRODUCTION; MARINE CUMULUS; NUCLEATION; PACIFIC; FIELDS; AIR AB Extensive airborne measurements of aerosol particles in a pristine marine region were made during the first Aerosol Characterization Experiment(ACE 1) from November 15 to December 14, 1995. During this study, high concentrations of condensation nuclei (CN) were frequently observed both near and within clouds. Near clouds, in the absence of liquid water, Clarke et al. [1998] have reported that high CN levels were from new particle formation by homogeneous nucleation. Here we show, however, that within clouds, elevated CN concentrations were not authentic, but instead a sampling artifact, likely related to fragmentation of cloud drops impacting the aerosol inlet. By themselves, these fragments were often indistinguishable from ambient particles. Spurious CN from fragmenting droplets were observed at temperatures down to roughly -20 degrees C and spanned a broad size range, with diameters down to 3 nm. Comparison of two different sized isokinetic aerosol inlets showed that inlets with smaller openings produce higher droplet fragment concentrations. The mechanism for producing these particles is not completely understood. Although fragmentation appeared to be the primary mechanism, for one instrument, an additional spurious source, correlated with liquid water, was observed when ambient temperatures were below -5 degrees C. These findings show that care must be taken when interpreting airborne aerosol measurements in regions of liquid water. This is particularly pertinent to studies of new particle formation by homogeneous nucleation in the vicinity of clouds. C1 Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Upton, NY 11973 USA. Univ Hawaii Manoa, Sch Ocean & Earth Sci & Technol, Honolulu, HI 96822 USA. Natl Ctr Atmospher Res, Res Aviat Facil, Boulder, CO 80307 USA. Univ Minnesota, Dept Mech Engn, Particle Technol Lab, Minneapolis, MN USA. RP Weber, RJ (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Environm Chem Div, Bldg 815E,POB 5000, Upton, NY 11973 USA. EM rweber@bnl.gov RI McMurry, Peter/A-8245-2008 OI McMurry, Peter/0000-0003-1609-5131 NR 35 TC 43 Z9 43 U1 3 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 NOV 20 PY 1998 VL 103 IS D21 BP 28337 EP 28346 DI 10.1029/98JD02086 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 140GF UT WOS:000077078700022 ER PT J AU Rydberg, B Holley, WR Mian, IS Chatterjee, A AF Rydberg, B Holley, WR Mian, IS Chatterjee, A TI Chromatin conformation in living cells: Support for a zig-zag model of the 30 nm chromatin fiber SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE ionizing radiation; DNA breaks; chromatin fiber; nucleosome; zig-zag model ID DNA STRAND BREAKS; IONIZING-RADIATION; SUPERSTRUCTURE; VARIABILITY; FRAGMENTS; CLUSTERS; RIBBON AB A new method was used to probe the conformation of chromatin in living mammalian cells. The method employs ionizing radiation and is based on the concept that such radiation induces correlated breaks in DNA strands that are in spatial proximity. Human dermal fibroblasts in G(0) phase of the cell cycle and Chinese hamster ovary cells in mitosis were irradiated by X-rays or accelerated ions. Following lysis of the cells, DNA fragments induced by correlated breaks were end-labeled and separated according to size on denaturing polyacrylamide gels. A characteristic peak was obtained for a fragment size of 78 bases, which is the size that corresponds to one turn of DNA around the nucleosome. Additional peaks between 175 and 450 bases reflect the relative position of nearest-neighbor nucleosomes. Theoretical calculations that simulate the indirect and direct effect of radiation on DNA demonstrate that the fragment size distributions are closely related to the chromatin structure model used. Comparison of the experimental data with theoretical results support a zig-zag model of the chromatin fiber rather than a simple helical model. Thus, radiation-induced damage analysis can provide information on chromatin structure in the living cell. (C) 1998 Academic Press. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Chatterjee, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, 1 Cyclotron Rd,MS29-100, Berkeley, CA 94720 USA. EM A_Chattejee@bl.gov NR 27 TC 78 Z9 81 U1 3 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 NOV 20 PY 1998 VL 284 IS 1 BP 71 EP 84 DI 10.1006/jmbi.1998.2150 PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 140KV UT WOS:000077087200007 PM 9811543 ER PT J AU Walensky, LD Shi, ZT Blackshaw, S DeVries, AC Demas, GE Gascard, P Nelson, RJ Conboy, JG Rubin, EM Snyder, SH Mohandas, N AF Walensky, LD Shi, ZT Blackshaw, S DeVries, AC Demas, GE Gascard, P Nelson, RJ Conboy, JG Rubin, EM Snyder, SH Mohandas, N TI Neurobehavioral deficits in mice lacking the erythrocyte membrane cytoskeletal protein 4.1 SO CURRENT BIOLOGY LA English DT Article ID IDENTIFICATION; SPECTRIN; RNA AB The erythrocyte membrane cytoskeletal protein 4.1 (4.1R) is a structural protein that confers stability and flexibility to erythrocytes via interactions with the cytoskeletal proteins spectrin and F-actin and with the band 3 and glycophorin C membrane proteins. Mutations in 4.1R can cause hereditary elliptocytosis, a disease characterized by a loss of the normal discoid morphology of erythrocytes, resulting in hemolytic anemia [1], Different isoforms of the 4.1 protein have been identified in a wide variety of nonerythroid tissues by immunological methods [2-5]. The variation in molecular weight of these different 4.1 isoforms, which range from 30 to 210 kDa [6], has been attributed to complex alternative splicing of the 4.1R gene [7]. We recently identified two new 4.1 genes: one is generally expressed throughout the body (4.1G) [8] and the other is expressed in central and peripheral neurons (4.1N) [9]. Here, we examined 4.1R expression by in situ hybridization analysis and found that 4.1R was selectively expressed in hematopoietic tissues and in specific neuronal populations, In the brain, high levels of 4.1R were discretely localized to granule cells in the cerebellum and dentate gyrus. We generated mice that lacked 4.1R expression; these mice had deficits in movement, coordination, balance and learning, in addition to the predicted hematological abnormalities. The neurobehavioral findings are consistent with the distribution of 4.1R in the brain, suggesting that 4.1R performs specific functions in the central nervous system. (C) Current Biology Ltd ISSN 0960-9822. C1 Johns Hopkins Sch Med, Dept Neurosci, Baltimore, MD 21205 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA 94270 USA. Johns Hopkins Univ, Dept Psychol, Baltimore, MD 21218 USA. Johns Hopkins Sch Med, Dept Anesthesiol & Crit Care Med, Baltimore, MD 21205 USA. Johns Hopkins Sch Med, Dept Pharmacol & Mol Sci, Baltimore, MD 21205 USA. Johns Hopkins Sch Med, Dept Psychiat, Baltimore, MD 21205 USA. RP Snyder, SH (reprint author), Johns Hopkins Sch Med, Dept Neurosci, Baltimore, MD 21205 USA. OI Nelson, Randy/0000-0002-8194-4016 FU NIDDK NIH HHS [DK 32094]; NIMH NIH HHS [MH 57760, MH 57535] NR 16 TC 45 Z9 47 U1 1 U2 2 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON W1P 6LE, ENGLAND SN 0960-9822 J9 CURR BIOL JI Curr. Biol. PD NOV 19 PY 1998 VL 8 IS 23 BP 1269 EP 1272 DI 10.1016/S0960-9822(07)00536-2 PG 4 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA 140VQ UT WOS:000077109400017 PM 9822582 ER PT J AU Davis, WB Wasielewski, MR Kosloff, R Ratner, MA AF Davis, WB Wasielewski, MR Kosloff, R Ratner, MA TI Semigroup representations, site couplings, and relaxation in quantum systems SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID BROWNIAN-MOTION; DYNAMICAL SEMIGROUPS; REDFIELD EQUATION; ELECTRON-TRANSFER; HEAT ENGINE; TIME; SPECTROSCOPY; DISSIPATION; SPACE; MODEL AB The semigroup formalism permits a general description of relaxation processes in quantum mechanical systems coupled to Markovian baths. From its definition, the semigroup formalism should be expressed in terms of the dissipative and relaxation coupling of the eigenstates of the quantum system to the bath modes. Often, for convenience both in calculation and in physical interpretation, it is more straightforward to couple local states of the quantum mechanical system to the bath. Within a simple two-site system, we examine the generalities of these two different coupling schemes, noting situations in which they are the same and situations for which substantial differences occur. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Hebrew Univ Jerusalem, Fritz Haber Res Ctr Mol Dynam, IL-90904 Jerusalem, Israel. Hebrew Univ Jerusalem, Dept Chem Phys, IL-90904 Jerusalem, Israel. RP Northwestern Univ, Dept Chem, 2145 Sheridan Rd, Evanston, IL 60208 USA. RI Kosloff, Ronnie/D-2388-2013 OI Kosloff, Ronnie/0000-0001-6201-2523 NR 60 TC 20 Z9 21 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 19 PY 1998 VL 102 IS 47 BP 9360 EP 9366 DI 10.1021/jp9813544 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 165GY UT WOS:000078514000006 ER PT J AU Wang, HB Thompson, WH Miller, WH AF Wang, HB Thompson, WH Miller, WH TI "Direct" calculation of thermal rate constants for the F+H-2 -> HF+F reaction SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; POTENTIAL-ENERGY SURFACE; DEPENDENT SCHRODINGER-EQUATION; ARRANGEMENT DECOUPLING POTENTIALS; IMAGINARY ABSORBING POTENTIALS; TRANSITION-STATE REGION; F+H-2 REACTION; PHOTOELECTRON-SPECTROSCOPY; BOUNDARY-CONDITIONS; QUANTUM AB We present "direct" calculations of the thermal rate constant for the F + H-2 reaction. The rate is obtained from the time integral of the flux-flux autocorrelation function, which is efficiently evaluated by taking advantage of the low rank of the half-Boltzmannized flux operator. Total rate constants are obtained from exact total angular momentum J not equal 0 calculations and compared with approximate approaches for including nonzero J. The rate constants obtained for the F + H-2 reaction on the new, highly accurate Stark-Werner potential energy surface are in good agreement with previous experimental results. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Miller, WH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RI Wang, Haobin/E-1208-2011; OI Thompson, Ward/0000-0002-3636-6448 NR 64 TC 22 Z9 22 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 19 PY 1998 VL 102 IS 47 BP 9372 EP 9379 DI 10.1021/jp981461y PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 165GY UT WOS:000078514000008 ER PT J AU Althorpe, SC Kouri, DJ Hoffman, DK AF Althorpe, SC Kouri, DJ Hoffman, DK TI Application of the time-independent wave packet reactant-product decoupling method to the (J=0) Li+HF reaction SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DEPENDENT SCHRODINGER-EQUATION; STATE REACTION PROBABILITIES; FILTER-DIAGONALIZATION; EXCHANGE-REACTION; SCATTERING; WAVEPACKET; QUANTUM; FORMULATION; DERIVATION; ACCURATE AB The time-independent wave packet reactant-product decoupling (TIW-RPD) method is a new method for calculating state-to-state reaction probabilities, which we recently developed by extending the original reactant-product decoupling method of Peng and Zhang (Peng, T.; Zharg, J. Z. H. J. Chem. Phys. 1996, 105, 6072; Zhu, W.; Peng, T.; Zhang, J. Z. H. J. Chem. Phys. 1997, 106, 1742). In the TIW-RPD method, the nuclear dynamics Schroedinger equation is partitioned into a set of completely decoupled equations, each of which describes the nuclear dynamics in either the reactant channel, one of the product channels, or the strong-interaction region. In this paper we apply the TIW-RPD method to the (three-dimensional) Li + HF --> LiF + H (J = 0) reaction. We also describe an improvement to the reactant channel part of the method. The state-to-state reaction probabilities for Li + HF converge very well with respect to the size of the strong-interaction region, demonstrating that the TIW-RPD method is robust enough to be applied to a wide range of chemical reactions, including those in which the dynamics are influenced by a long-range potential energy surface. C1 Univ Houston, Dept Chem, Houston, TX 77204 USA. Univ Houston, Dept Phys, Houston, TX 77204 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Althorpe, SC (reprint author), Natl Res Council, Steacie Inst Mol Sci, Ottawa, ON K1N OR6, Canada. NR 26 TC 18 Z9 18 U1 0 U2 5 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 NOV 19 PY 1998 VL 102 IS 47 BP 9494 EP 9499 DI 10.1021/jp981992m PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 165GY UT WOS:000078514000024 ER PT J AU Dvorak, J Hrbek, J AF Dvorak, J Hrbek, J TI Adsorbate ordering effects in the trimerization reaction of acetylene on Cu(100) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ELECTRON-IMPACT IONIZATION; SURFACE ALLOYS; BENZENE; ADSORPTION; C2H2; CHEMISORPTION; CYCLIZATION; DESORPTION; CATALYSIS; CU(110) AB The trimerization of acetylene to benzene on a Cu(100) surface is reported. The reaction occurs at both room temperature and at or below 200 K depending on the coverage. The reaction yield exhibits a strong coverage dependence, with the yield increasing as the initial acetylene coverage increases. The maximum yield for the room temperature reaction is 30%. The structural properties of the acetylene overlayer have been investigated by LEED, and the results correlated with the reaction yield observations. The results are discussed in light of the coverage dependence of the benzene yield for the same reaction on Cu(110) and Pd(lll). It is found that the structural arrangement of the acetylene overlayer on the three different surfaces explains the different coverage dependences of the reaction yield. A unique feature is observed in the thermal desorption data for this system; the mass 26 signal mimics the trimerization reaction rate at high coverages. This is most likely due to the exothermicity of the benzene reaction, leading to the desorption of vibrationally hot benzene molecules, or the transfer of energy to nearby acetylene molecules, resulting in simultaneous desorption. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Penn, Dept Chem, Philadelphia, PA 19104 USA. RP Dvorak, J (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM dvorak@bnl.gov RI Hrbek, Jan/I-1020-2013 NR 36 TC 15 Z9 16 U1 0 U2 5 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 NOV 19 PY 1998 VL 102 IS 47 BP 9443 EP 9450 DI 10.1021/jp981956n PG 8 WC Chemistry, Physical SC Chemistry GA 165GZ UT WOS:000078514100013 ER PT J AU Kanner, GS Butt, DP AF Kanner, GS Butt, DP TI Raman and electrochemical probes of the dissolution kinetics of tungsten in hydrogen peroxide SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID H2O2 SOLUTIONS; WO3; FILMS AB The interaction of tungsten with hydrogen peroxide was studied by Raman spectroscopy and electrochemical measurements. We found that W catalyzes the decomposition of peroxide into its ion, while the native oxide of W becomes increasingly hydrated and soluble. The decay of the peroxide concentration upon immersion of W is consistent with a model of 1-D diffusion to the W surface followed by a surface reaction with a heterogeneous rate constant of 3 x 10(-5) cm/s. This model can also be used to explain the decrease of the H2O2 solution pH and the increase in open circuit potential of W that occurs while W is immersed in H2O2. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Kanner, GS (reprint author), No Arizona Univ, Dept Phys & Astron, POB 6010, Flagstaff, AZ 86011 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 28 TC 6 Z9 6 U1 2 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD NOV 19 PY 1998 VL 102 IS 47 BP 9501 EP 9507 DI 10.1021/jp982716a PG 7 WC Chemistry, Physical SC Chemistry GA 165GZ UT WOS:000078514100019 ER PT J AU Lipoglavsek, M Seweryniak, D Davids, CN Fahlander, C Gorska, M Janssens, RVF Nyberg, J Uusitalo, J Walters, WB Ahmad, I Blomqvist, J Carpenter, MP Cizewski, JA Fischer, SM Grawe, H Hackman, G Huhta, M Lister, CJ Nisius, D Poli, G Reiter, P Ressler, J Schwartz, J Sonzogni, A AF Lipoglavsek, M Seweryniak, D Davids, CN Fahlander, C Gorska, M Janssens, RVF Nyberg, J Uusitalo, J Walters, WB Ahmad, I Blomqvist, J Carpenter, MP Cizewski, JA Fischer, SM Grawe, H Hackman, G Huhta, M Lister, CJ Nisius, D Poli, G Reiter, P Ressler, J Schwartz, J Sonzogni, A TI E2 polarization charge in Sn-102 SO PHYSICS LETTERS B LA English DT Article ID DRIP-LINE NUCLEI; IN-BEAM; MODEL AB The nucleus Sn-102, which is the lightest Sn isotope with known excited states, was investigated with the Cr-50(Ni-58, alpha 2n) reaction using delayed in-beam gamma-ray and conversion-electron spectroscopy. The experimental setup was designed to study the decay of mu s-long isomeric states by placing gamma-ray and electron detectors behind the focal plane of the Fragment Mass Analyzer at the Argonne National Laboratory. A 44 keV conversion-electron line corresponding to the (6(+))-->(4(+)) transition in Sn-102 was identified and a half-life of 0.62(-0.19)(+0.43) mu s was measured for the (6(+)) state. From the available experimental information neutron effective charges from 1.6 to 2.3 e were deduced, based on the comparison with different shell-model calculations, (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Lund, Dept Phys, Div Cosm & Subatom Phys, Lund, Sweden. Jozef Stefan Inst, Ljubljana, Slovenia. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Maryland, Dept Chem, College Pk, MD 20742 USA. Gesell Schwerionenforsch GmbH, D-6100 Darmstadt, Germany. Warsaw Univ, Inst Expt Phys, Warsaw, Poland. Uppsala Univ, Svedberg Lab, Uppsala, Sweden. Royal Inst Technol, S-10044 Stockholm, Sweden. Rutgers State Univ, Dept Phys & Astron, New Brunswick, NJ 08903 USA. Michigan State Univ, Natl Superconducting Cyclotron Lab, E Lansing, MI 48824 USA. Univ Milan, Ist Fis Gen Appl, I-20133 Milan, Italy. RP Lipoglavsek, M (reprint author), Univ Lund, Dept Phys, Div Cosm & Subatom Phys, Solvegatan 14, Lund, Sweden. RI Ressler, Jennifer Jo/F-2279-2010; Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 12 TC 29 Z9 29 U1 0 U2 1 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 NOV 19 PY 1998 VL 440 IS 3-4 BP 246 EP 250 DI 10.1016/S0370-2693(98)01178-2 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 143DD UT WOS:000077239000003 ER PT J AU Clark, RM Kruchen, R Asztalos, SJ Becker, JA Busse, B Chmel, S Deleplanque, MA Diamond, RM Fallon, P Jenkins, D Hauschild, K Hibbert, IM Hubel, H Lee, IY Macchiavelli, AO MacLeod, RW Schmid, G Stephens, FS van Severen, UJ Vetter, K Wadsworth, R Wan, S AF Clark, RM Kruchen, R Asztalos, SJ Becker, JA Busse, B Chmel, S Deleplanque, MA Diamond, RM Fallon, P Jenkins, D Hauschild, K Hibbert, IM Hubel, H Lee, IY Macchiavelli, AO MacLeod, RW Schmid, G Stephens, FS van Severen, UJ Vetter, K Wadsworth, R Wan, S TI The shears mechanism in the lead isotopes SO PHYSICS LETTERS B LA English DT Article ID COLLECTIVE OBLATE; DIPOLE BANDS; PB-196; LIFETIMES; STATES AB Lifetimes of states in at least one of the M1 bands in each nucleus from Pb193-197 have been determined through Doppler-Shift Attenuation Method experiments performed with the Gammasphere array. The nuclei were populated under similar conditions allowing accurate relative measurements of the state lifetimes. The deduced B(M1) values display the characteristic decrease with increasing angular momentum which is a clear signature of the shears mechanism. Combined with the recent results for Pb-198,Pb-199 an impressive body of evidence now exists which supports the interpretation of these structures as examples of a new mode of nuclear behavior: 'magnetic rotation'. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Bonn, Inst Strahlen & Kernphys, D-53115 Bonn, Germany. Univ York, Dept Phys, York YO1 5DD, N Yorkshire, England. Gesell Schwerionenforsch mbH, D-64291 Darmstadt, Germany. RP Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Hauschild, Karl/A-6726-2009; Kruecken, Reiner/A-1640-2013 OI Kruecken, Reiner/0000-0002-2755-8042 NR 29 TC 42 Z9 43 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 NOV 19 PY 1998 VL 440 IS 3-4 BP 251 EP 256 DI 10.1016/S0370-2693(98)01179-4 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 143DD UT WOS:000077239000004 ER PT J AU Hawes, FT Maris, P Roberts, CD AF Hawes, FT Maris, P Roberts, CD TI Infrared behaviour of propagators and vertices SO PHYSICS LETTERS B LA English DT Article DE gluon and Quark Schwinger functions; dynamical chiral symmetry breaking; confinement; Dyson-Schwinger equations; lattice-QCD ID CHIRAL-SYMMETRY BREAKING; VANISHING GLUON PROPAGATOR; DYSON-SCHWINGER-EQUATIONS; NONPERTURBATIVE SOLUTION; SELF-CONSISTENCY; VERTEX; QCD; CONFINEMENT; MODEL AB We elucidate constraints imposed by confinement and dynamical chiral symmetry breaking on the infrared behaviour of the dressed-quark and -gluon propagators, and dressed-quark-gluon vertex. In covariant gauges the dressing of the gluon propagator is completely specified by P(k(2)): = 1/[1 + Pi(k(2))], where Pi(k(2)) is the vacuum polarisation. In the absence of particle-like singularities in the dressed-quark-gluon vertex, extant proposals for the dressed-gluon propagator that manifest P(k(2) = 0)= 0 and max(P(k(2))) similar to 10 neither confine quarks nor break chiral symmetry dynamically. This class includes all existing estimates of P(k(2)) via numerical simulations. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Adelaide, Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Hawes, FT (reprint author), Univ Adelaide, Ctr Subatom Struct Matter, Adelaide, SA 5005, Australia. OI Roberts, Craig/0000-0002-2937-1361 NR 26 TC 51 Z9 51 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 NOV 19 PY 1998 VL 440 IS 3-4 BP 353 EP 358 DI 10.1016/S0370-2693(98)01105-8 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 143DD UT WOS:000077239000019 ER PT J AU Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, P Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Fernandez, A Fox, GF Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yi, D Yang, SM Yoshida, S Zaliznyak, R Zhang, C AF Aitala, EM Amato, S Anjos, JC Appel, JA Ashery, D Banerjee, S Bediaga, I Blaylock, G Bracker, SB Burchat, P Burnstein, RA Carter, T Carvalho, HS Copty, NK Cremaldi, LM Darling, C Denisenko, K Fernandez, A Fox, GF Gagnon, P Gobel, C Gounder, K Halling, AM Herrera, G Hurvits, G James, C Kasper, PA Kwan, S Langs, DC Leslie, J Lundberg, B MayTal-Beck, S Meadows, B Neto, JRTD Mihalcea, D Milburn, RH de Miranda, JM Napier, A Nguyen, A d'Oliveira, AB O'Shaughnessy, K Peng, KC Perera, LP Purohit, MV Quinn, B Radeztsky, S Rafatian, A Reay, NW Reidy, JJ dos Reis, AC Rubin, HA Sanders, DA Santha, AKS Santoro, AFS Schwartz, AJ Sheaff, M Sidwell, RA Slaughter, AJ Sokoloff, MD Solano, J Stanton, NR Stefanski, RJ Stenson, K Summers, DJ Takach, S Thorne, K Tripathi, AK Watanabe, S Weiss-Babai, R Wiener, J Witchey, N Wolin, E Yi, D Yang, SM Yoshida, S Zaliznyak, R Zhang, C CA Fermilab E791 Collaboration TI Measurement of the form-factor ratios for D+->(K)over-bar(star 0)l(+)nu(l) SO PHYSICS LETTERS B LA English DT Article ID SEMILEPTONIC DECAYS; MESON DECAYS; LATTICE; MODEL; QCD AB The form factor ratios r(V)= V(0)/A(1)(0), r(2)=A(2)(0)/A(1)(0) and r(3)=A(3)(0)/A(1)(0) in the decay D+-->(K) over bar*(0)l(+)nu(l) (K) over bar*(0) --> K- pi(+) have been measured using data from charm hadroproduction experiment E791 at Fermilab. From 3034 (595) signal (background) events in the muon channel, we obtain r(V) = 1.84 +/- 0.11 +/- 0.09, r(2) = 0.75 +/- 0.08 +/- 0.09 and, as a first measurement of r(3), we find 0.04 +/- 0.33 +/- 0.29. The values of the form factor ratios r(V) and r(2) measured for the muon channel are combined with the values of r(V) and r(2) that we have measured in the electron channel. The combined E791 results for the muon and electron channels are r(V)= 1.87 +/- 0.08 +/- 0.07 and r(2) = 0.73 +/- 0.06 +/- 0.08. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Mississippi, University, MS 38677 USA. Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil. Univ Calif Santa Cruz, Santa Cruz, CA 95064 USA. Univ Cincinnati, Cincinnati, OH 45221 USA. CINVESTAV, Mexico City 14000, DF, Mexico. Fermilab Astrophys Ctr, Batavia, IL 60510 USA. IIT, Chicago, IL 60616 USA. Kansas State Univ, Manhattan, KS 66506 USA. Univ Massachusetts, Amherst, MA 01003 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Autonoma Puebla, Mexico City, DF, Mexico. Univ S Carolina, Columbia, SC 29208 USA. Stanford Univ, Stanford, CA 94305 USA. Tel Aviv Univ, IL-69978 Tel Aviv, Israel. Tufts Univ, Medford, MA 02155 USA. Univ Wisconsin, Madison, WI 53706 USA. Yale Univ, New Haven, CT 06511 USA. RP Univ Mississippi, University, MS 38677 USA. RI Anjos, Joao/C-8335-2013; Gobel Burlamaqui de Mello, Carla /H-4721-2016 OI Gobel Burlamaqui de Mello, Carla /0000-0003-0523-495X NR 24 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD NOV 19 PY 1998 VL 440 IS 3-4 BP 435 EP 441 DI 10.1016/S0370-2693(98)01243-X PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 143DD UT WOS:000077239000027 ER PT J AU Lorkovic, IM Miranda, KM Lee, B Bernhard, S Schoonover, JR Ford, PC AF Lorkovic, IM Miranda, KM Lee, B Bernhard, S Schoonover, JR Ford, PC TI Flash photolysis studies of the ruthenium(II) porphyrins Ru(P)(NO)(ONO). Multiple pathways involving reactions of intermediates with nitric oxide SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID STRUCTURAL CHARACTERIZATION; RELAXING FACTOR; EXCITED-STATES; AXIAL-LIGAND; COMPLEXES; TETRAPHENYLPORPHYRIN; PHOTOCHEMISTRY; OCTAETHYLPORPHYRIN; FERRIHEMOPROTEINS; SPECTROSCOPY AB Described are the spectra and kinetics of transients formed by laser flash photolysis of the ruthenium nitrosyl nitrito complexes Ru(P)(NO)(ONO), P = TPP (meso-tetraphenylporphyrin), OEP (octaethylporphyrin), TmTP (tetra(m-tolyl)porphyrin), and FTTP (tetra(m-trifluoromethylphenyl)porphyrin) in benzene solutions. Two transient decay processes are seen on the time frame (<1 ms) of the flash photolysis experiment, and a residual difference spectrum, which decays to baseline on a longer time frame, is noted as well. The accumulated evidence points to the formation of two primary photoproducts, Ru(P)(ONO) (A) formed by NO photolabilization and Ru(P)(NO) (B) formed by NO2 photolabilization. Both decay by NO dependent pathways, the reaction of A with NO to re-form Ru(P)(NO)(ONO) being substantially faster (2.4-5.5 x 10(8) M-1 s(-1) in ambient temperature benzene) than the reaction of B with NO (2.4-10 x 10(7) M-1 s(-1)). The product of the latter reaction is apparently the dinitrosyl complex Ru(P)(NO)(2), which undergoes a much slower thermal reaction with excess NO to give again Ru(P)(NO)(ONO). The possibility of B being the oxo complex O=Ru(P)(NO) formed by NO loss from coordinated nitrite was considered but concluded to be a minor pathway at best. Isotopic exchange reactions using either labeled complex or labeled NO in cyclohexane demonstrate photochemical exchange of NO into both the nitrosyl and nitrito complexes, and time-resolved infrared experiments are consistent with formation of a long-lived nitrosyl-containing intermediate. Flash photolysis studies of the respective nitrosyl chloro complexes Ru(TPP)(NO)Cl and Ru(OEP)(NO)Cl indicate that only a single transient species, presumably Ru(P)Cl, is formed in each case, and this decays by a single NO dependent pathway back to starting material. C1 Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. Univ Calif Los Alamos Natl Lab, Biosci Biotechnol Grp CST4, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. RP Miranda, KM (reprint author), Univ Calif Santa Barbara, Dept Chem, Santa Barbara, CA 93106 USA. RI Bernhard, Stefan/A-9389-2008; Miranda, Katrina/B-7823-2009; Ford, Peter/D-1826-2011 OI Ford, Peter/0000-0002-5509-9912 NR 43 TC 81 Z9 81 U1 4 U2 16 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 NOV 18 PY 1998 VL 120 IS 45 BP 11674 EP 11683 DI 10.1021/ja981907o PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA 141AC UT WOS:000077119600016 ER PT J AU Elliott, CM Derr, DL Matyushov, DV Newton, MD AF Elliott, CM Derr, DL Matyushov, DV Newton, MD TI Direct experimental comparison of the theories of thermal and optical electron-transfer: Studies of a mixed-valence dinuclear iron polypyridyl complex SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID INTERVALENCE CHARGE-TRANSFER; TRANSITION-METAL COMPLEXES; SOLVENT REORGANIZATION; CRYSTAL-STRUCTURES; MATRIX-ELEMENTS; HUSH THEORY; ION-PAIRS; ELECTROABSORPTION; SPECTROSCOPY; DEPENDENCE AB The spectral parameters for the optically induced intervalence charge transfer and the rates of thermal electron transfer as a function of temperature have been measured for a rigid, triply linked mixed-valence dinuclear tris(2,2'-bipyridine)iron complex: The total reorganizational energy associated with the intramolecular electron exchange in this complex is almost:exclusively outer-sphere in nature and comes from thermal fluctuations of the solvent. Thus, the system can be treated rigorously at the classical level, where in this context classical refers to treatments of the nuclear modes. The theories developed to describe the optical electron transfer and the thermal electron transfer are evaluated by analysis of the Spectral and rate data, respectively. The quantities common to both theories are the donor-acceptor coupling matrix element, H-12, and the total reorganizational energy. Applying the respective theories to the appropriate corresponding sets of data yields reorganizational energies that are in excellent agreement irrespective of the manner in which the temperature dependence is treated; however, if the reorganizational energy is assumed to be temperature independent; H-12(th) (from the rate data) and H-12(op) (from the spectral data) differ by a statistically significant factor of similar to 2.5. If the theoretically predicted temperature-dependent reorganizational energy composed of orientational reorganization of permanent dipoles and reorganization of solvent density is used in the calculations, the agreement between H-12(op) and H-12(th) improves dramatically. To our knowledge, this work constitutes the first attempt to experimentally compare these two classical theories with this level of rigor. Supplementing the experimental comparisons, we have conducted self-consistent-field (SCF) and configuration interaction (CI) calculations to obtain theoretical values of H-12(op) and the donor-acceptor orbital separation, r for comparison with experimentally determined values. C1 Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Elliott, CM (reprint author), Colorado State Univ, Dept Chem, Ft Collins, CO 80523 USA. OI Matyushov, Dmitry/0000-0002-9352-764X NR 59 TC 62 Z9 62 U1 0 U2 11 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 NOV 18 PY 1998 VL 120 IS 45 BP 11714 EP 11726 DI 10.1021/ja981067d PG 13 WC Chemistry, Multidisciplinary SC Chemistry GA 141AC UT WOS:000077119600021 ER PT J AU Nicholas, JB Haw, JF AF Nicholas, JB Haw, JF TI The prediction of persistent carbenium ions in zeolites SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID IN-SITU NMR; ACIDIC ZEOLITES; CATALYST C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Texas A&M Univ, Dept Chem, Ctr Catalysis, College Stn, TX 77842 USA. RP Nicholas, JB (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, 906 Battelle Blvd, Richland, WA 99352 USA. NR 19 TC 65 Z9 65 U1 0 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD NOV 18 PY 1998 VL 120 IS 45 BP 11804 EP 11805 DI 10.1021/ja982012e PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 141AC UT WOS:000077119600035 ER PT J AU Gavel, OY Bursakov, SA Calvete, JJ George, GN Moura, JJG Moura, I AF Gavel, OY Bursakov, SA Calvete, JJ George, GN Moura, JJG Moura, I TI ATP sulfurylases from sulfate-reducing bacteria of the genus Desulfovibrio. A novel metalloprotein containing cobalt and zinc SO BIOCHEMISTRY LA English DT Article ID ABSORPTION FINE-STRUCTURE; PENICILLIUM-CHRYSOGENUM; RIFTIA-PACHYPTILA; HIGHER-PLANTS; ACTIVE-SITE; PURIFICATION; RUBREDOXIN; ENZYMES; SPECTROSCOPY; IDENTIFICATION AB Adenosine triphosphate sulfurylase catalyzes the formation of adenosine 5'-phosphosulfate from adenosine triphosphate and sulfate. The enzyme plays a crucial role in sulfate activation, the key step for sulfate utilization, and has been purified from crude extracts of Desulfovibrio desulfuricans ATCC 27774 and Desulfovibrio gigas. Both proteins are homotrimers [141 kDa (3 x 47) for D. desulfuricans and 147 kDa (3 x 49) for D. gigas] and have been identified, for the first time, as metalloproteins containing cobalt and zinc. EXAFS reveals that either cobalt or zinc binds endogenously at presumably equivalent metal binding sites and is tetrahedrally coordinated to one nitrogen and three sulfur atoms. Furthermore, the electronic absorption spectra display charge-transfer bands at 335 and 370 nm consistent with sulfur coordination to cobalt, and as expected for a distorted tetrahedral cobalt geometry, d-d bands are observed at 625, 666, and 715 nm. This geometry is supported by the observation of high-spin Co2+ EPR signals at g approximate to 6.5. C1 Univ Nova Lisboa, Fac Ciencias & Tecnol, Ctr Quim Fina & Biotecnol, Dept Quim, P-2825 Monte De Caparica, Portugal. Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. CSIC, Inst Invest Biomed, Valencia, Spain. RAS, AN Bach Inst Biochem, Moscow 117071, Russia. RP Moura, I (reprint author), Univ Nova Lisboa, Fac Ciencias & Tecnol, Ctr Quim Fina & Biotecnol, Dept Quim, P-2825 Monte De Caparica, Portugal. EM isa@dq.fct.unl.pt RI Moura, Jose/D-6426-2013; George, Graham/E-3290-2013; REQUIMTE, SMB/M-5694-2013; Moura, Isabel/D-6339-2013; REQUIMTE, UCIBIO/N-9846-2013; Calvete, Juan/K-9619-2014; OI Moura, Jose/0000-0002-4726-2388; Moura, Isabel/0000-0003-0971-4977; Calvete, Juan/0000-0001-5026-3122; Gavel, Olga/0000-0001-9838-6770 NR 60 TC 48 Z9 49 U1 2 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 NOV 17 PY 1998 VL 37 IS 46 BP 16225 EP 16232 DI 10.1021/bi9816709 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 141AH UT WOS:000077120100021 PM 9819214 ER PT J AU Winokur, MJ Mattes, BR AF Winokur, MJ Mattes, BR TI Structural studies of halogen acid doped polyaniline and the role of water hydration SO MACROMOLECULES LA English DT Article ID X-RAY-SCATTERING; CRYSTALLINE-STRUCTURE; CONDUCTING POLYMER; METAL; STATE; POLY(P-PHENYLENEVINYLENE); OXIDATION; PHASES AB The structural ordering within crystalline polyaniline (PANI) powders as emeraldine (i.e., at 50% oxidation) in both its base (EB) and halogen acid doped salt (ES) forms has been studied using X-ray diffraction. PANI-ES powder precipitates, obtained immediately after synthesis, have significant crystalline fractions which nominally approximate the proposed pseudo-orthorhombic type I (ES-I) salt structure (Pouget, J. P.; et al. Macromolecules 1991, 24, 779). Additional treatments, such as dedoping by immersion in NH4OH solution and redoping by aqueous HF acid, lead to further changes in the structure with the appearance of additional crystalline phases. The role of water hydration in this structural evolution is also examined, and significant structural variations are found to occur with radically different time scales. Comparison of the data with structure factor calculations leads to new structural models that identify changes in the PANI chain packing and, in the case of HCl doping, correlate these with the known variations in the charge transport properties. C1 Univ Wisconsin, Dept Phys, Madison, WI 53706 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Winokur, MJ (reprint author), Univ Wisconsin, Dept Phys, 1150 Univ Ave, Madison, WI 53706 USA. NR 46 TC 34 Z9 34 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 17 PY 1998 VL 31 IS 23 BP 8183 EP 8191 DI 10.1021/ma980586y PG 9 WC Polymer Science SC Polymer Science GA 141MM UT WOS:000077147800025 ER PT J AU Melnichenko, YB Wignall, GD Van Hook, WA Szydlowski, J Wilczura, H Rebelo, LP AF Melnichenko, YB Wignall, GD Van Hook, WA Szydlowski, J Wilczura, H Rebelo, LP TI Comparison of inter- and intramolecular correlations of polystyrene in poor and Theta solvents via small-angle neutron scattering SO MACROMOLECULES LA English DT Article ID CHAIN; BULK C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Univ Warsaw, Dept Chem, PL-02089 Warsaw, Poland. Univ Nova Lisboa, Dept Chem, P-2825 Monte De Caparica, Portugal. RP Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Rebelo, Luis Paulo/B-5285-2008 NR 18 TC 28 Z9 28 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 EI 1520-5835 J9 MACROMOLECULES JI Macromolecules PD NOV 17 PY 1998 VL 31 IS 23 BP 8436 EP 8438 DI 10.1021/ma9812480 PG 3 WC Polymer Science SC Polymer Science GA 141MM UT WOS:000077147800054 ER PT J AU Jimenez, I Garcia, MM Albella, JM Terminello, LJ AF Jimenez, I Garcia, MM Albella, JM Terminello, LJ TI Orientation of graphitic planes during the bias-enhanced nucleation of diamond on silicon: An x-ray absorption near-edge study SO APPLIED PHYSICS LETTERS LA English DT Article ID CORE-LEVEL PHOTOABSORPTION; BORON-NITRIDE; FILMS; DEPOSITION; DEFECTS; GROWTH AB The bias-enhanced nucleation of diamond on Si(100) is studied by angle-dependent x-ray absorption near-edge spectroscopy (XANES). During diamond nucleation, a graphitic phase is also detected. The angle dependence of the XANES signal shows that the graphitic basal planes are oriented perpendicular to the surface. Implications of this result on the mechanism of bias-enhanced nucleation are discussed. (C) 1998 American Institute of Physics. [S0003-6951(98)01646-5]. C1 CSIC, Inst Ciencia Mat Madrid, Madrid, Spain. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Jimenez, I (reprint author), CSIC, Inst Ciencia Mat Madrid, Madrid, Spain. RI Jimenez, Ignacio/F-7422-2010 OI Jimenez, Ignacio/0000-0001-5605-3185 NR 17 TC 22 Z9 22 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 NOV 16 PY 1998 VL 73 IS 20 BP 2911 EP 2913 PG 3 WC Physics, Applied SC Physics GA 136FW UT WOS:000076848700019 ER PT J AU Venezia, VC Eaglesham, DJ Haynes, TE Agarwal, A Jacobson, DC Gossmann, HJ Baumann, FH AF Venezia, VC Eaglesham, DJ Haynes, TE Agarwal, A Jacobson, DC Gossmann, HJ Baumann, FH TI Depth profiling of vacancy clusters in MeV-implanted Si using Au labeling SO APPLIED PHYSICS LETTERS LA English DT Article ID SILICON; DIFFUSION; DAMAGE; GOLD; DEFECTS AB A technique for profiling the clustered-vacancy region produced by high-energy ion implantation into silicon is described and tested. This technique takes advantage of the fact that metal impurities, such as Au, are trapped in the region of excess vacancies produced by MeV Si implants into silicon. In this work, the clustered-vacancy regions produced by 1-, 2-, and 8- MeV Si implants into silicon have been labeled with Au diffused in from the front surface at 750 degrees C. The trapped Au was profiled with Rutherford backscattering spectrometry. The dynamics of the clustered-vacancy region were monitored for isochronal annealing at 750-1000 degrees C, and for isothermal annealing at 950 degrees C, for 10-600 s. Cross-sectional transmission electron microscopy analysis revealed that after the drive-in anneal, the Au in the region of vacancy clusters is in the form of precipitates. The results demonstrate that the Au-labeling technique offers a convenient and potentially quantitative tool for depth profiling vacancies in clusters. (C) 1998 American Institute of Physics. [S0003-6951(98)05046-3]. C1 AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Eaton Corp, Div Semicond Equipment, Beverly, MA 01915 USA. Univ N Texas, Dept Phys, Denton, TX 76203 USA. RP Venezia, VC (reprint author), AT&T Bell Labs, Lucent Technol, 600 Mt Ave, Murray Hill, NJ 07974 USA. RI Haynes, Tony/P-8932-2015 OI Haynes, Tony/0000-0003-2871-4745 NR 22 TC 74 Z9 74 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 NOV 16 PY 1998 VL 73 IS 20 BP 2980 EP 2982 DI 10.1063/1.122650 PG 3 WC Physics, Applied SC Physics GA 136FW UT WOS:000076848700042 ER PT J AU Carlin, J AF Carlin, J TI Waste not want not? SO CHEMISTRY & INDUSTRY LA English DT Article C1 US DOE, Energy Informat Adm, Off Coal Nucl Elect & Alternate Fuels, Washington, DC 20585 USA. RP Carlin, J (reprint author), US DOE, Energy Informat Adm, Off Coal Nucl Elect & Alternate Fuels, Washington, DC 20585 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU SOC CHEMICAL INDUSTRY PI LONDON PA 14 BELGRAVE SQUARE, LONDON SW1X 8PS, ENGLAND SN 0009-3068 J9 CHEM IND-LONDON JI Chem. Ind. PD NOV 16 PY 1998 IS 22 BP 922 EP 925 PG 4 WC Chemistry, Applied SC Chemistry GA 141ER UT WOS:000077130100021 ER PT J AU Tong, H Jin, L AF Tong, H Jin, L TI Recombinant Chinese Pinyin system for efficient processing of information in Chinese SO COMPUTER STANDARDS & INTERFACES LA English DT Article DE Chinese Pinyin system; Chinish; coding system; information processing AB An enhanced Pinyin (Chinese phonetic symbol) coding system has been developed for creating a novel Romanized version of the Chinese language. The homophonic problem associated with inputting Chinese characters to computers has been solved by the addition of a suffix to the conventional Pinyin of individual Chinese characters as well as multisyllable words/phrases. The suffix for the Pinyin of a Chinese character comprises a combination of a tone symbol and a single letter index that is mostly designated as the first letter of an English word giving an appropriate translation. For multisyllable Chinese words, the suffix consists only of a single letter that indicates either the tone of the last Chinese character or the first letter of an English translation. The resulting set of Romanized Chinese notations, christened 'Chinish', make it possible to input Chinese characters as efficiently as English words. It is proposed that Chinish be used as a replacement for the current Pinyin system as a standard interface between Chinese speaking users and computers. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Argonne Natl Lab, BioCARS, Argonne, IL 60439 USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5489 J9 COMP STAND INTER JI Comput. Stand. Interfaces PD NOV 16 PY 1998 VL 20 IS 1 BP 25 EP 29 DI 10.1016/S0920-5489(98)00031-2 PG 5 WC Computer Science, Hardware & Architecture; Computer Science, Software Engineering SC Computer Science GA 153WU UT WOS:000077856900003 ER PT J AU Wiringa, RB Schiavilla, R AF Wiringa, RB Schiavilla, R TI Microscopic calculation of Li-6 elastic and transition form factors SO PHYSICAL REVIEW LETTERS LA English DT Article ID MONTE-CARLO CALCULATIONS; ELECTRON-SCATTERING; EXCHANGE CURRENTS; CROSS-SECTION; LIGHT-NUCLEI; 3-BODY; MODEL; ENERGIES; CAPTURE AB Variational Monte Carlo wave functions, obtained from a realistic Hamiltonian consisting of the Argonne vis two-nucleon and Urbana-IX three-nucleon interactions, are used to calculate the Li-6 ground-state longitudinal and transverse form factors as well as transition form factors to the first four excited states. The charge and current operators include one- and two-body components, leading terms of which are constructed consistently with the two-nucleon interaction. The calculated form factors and radiative widths are in good agreement with available experimental data. [S0031-9007(98)07634-0]. C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Jefferson Lab, Newport News, VA 23606 USA. Old Dominion Univ, Dept Phys, Norfolk, VA 23529 USA. RP Wiringa, RB (reprint author), Argonne Natl Lab, Div Phys, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Wiringa, Robert/M-4970-2015 NR 33 TC 44 Z9 44 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 NOV 16 PY 1998 VL 81 IS 20 BP 4317 EP 4320 DI 10.1103/PhysRevLett.81.4317 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CY UT WOS:000077011300010 ER PT J AU Whyte, DG Evans, TE Hyatt, AW Jernigan, TC Lee, RL Kellman, AG Parks, PB Stockdale, R Taylor, PL AF Whyte, DG Evans, TE Hyatt, AW Jernigan, TC Lee, RL Kellman, AG Parks, PB Stockdale, R Taylor, PL TI Rapid inward impurity transport during impurity pellet injection on the DIII-D tokamak SO PHYSICAL REVIEW LETTERS LA English DT Article ID VISIBLE SPECTROSCOPY; PLASMA; TIME AB Neon killer pellets are injected into the DIII-D tokamak plasma in order to radiatively quench the plasma's stored energy and mitigate disruption effects. Inward radial transport on the time scale of the pellet ablation (less than or equal to 1 ms) results in central deposition of the neon inside the ablation penetration radius of the pellet, causing effective radiative energy dissipation. This result is in contrast to the radially outward deposition measured for fueling (hydronenic) pellets. The observed magnitudes of magnetic fluctuations (delta B/B similar to 0.2%) are shown to be capable of causing the radial transport. C1 Univ Calif San Diego, San Diego, CA 92103 USA. Oak Ridge Natl Lab, Oak Ridge, TN USA. Gen Atom Co, San Diego, CA 92138 USA. RP Whyte, DG (reprint author), Gen Atom Co, POB 85608, San Diego, CA 92138 USA. NR 19 TC 18 Z9 19 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 16 PY 1998 VL 81 IS 20 BP 4392 EP 4395 DI 10.1103/PhysRevLett.81.4392 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CY UT WOS:000077011300029 ER PT J AU Launois, P Moret, R Hone, J Zettl, A AF Launois, P Moret, R Hone, J Zettl, A TI Evidence for distinct polymer chain orientations in KC60 and RbC60 SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL-INSULATOR-TRANSITION; NMR; RB; PRESSURE; AC(60); RB1C60; C-60; A=K; CS; DIFFRACTION AB The KC60 and RbC60 polymer phases exhibit contrasting electronic properties while powder diffraction studies have revealed no definite structural difference. We have performed single crystal x-ray diffraction and diffuse scattering studies of these compounds. It is found that KC60 and RbC60 possess different chain orientations about their axes, which are described by distinct space groups Pmnn and I2/m, respectively. Such a structural difference will be of great importance to a complete understanding of the physical properties. C1 Univ Paris Sud, Phys Solides Lab, URA CNRS 2, F-91405 Orsay, France. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Launois, P (reprint author), Univ Paris Sud, Phys Solides Lab, URA CNRS 2, Bat 510, F-91405 Orsay, France. RI Hone, James/E-1879-2011; Zettl, Alex/O-4925-2016 OI Hone, James/0000-0002-8084-3301; Zettl, Alex/0000-0001-6330-136X NR 28 TC 61 Z9 62 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 NOV 16 PY 1998 VL 81 IS 20 BP 4420 EP 4423 DI 10.1103/PhysRevLett.81.4420 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CY UT WOS:000077011300036 ER PT J AU Kiely, JD Hwang, RQ Houston, JE AF Kiely, JD Hwang, RQ Houston, JE TI Effect of surface steps on the plastic threshold in nanoindentation SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORCE MICROSCOPY; MONOLAYER FILMS AB Using interfacial force microscopy and passivated Au surfaces, we have investigated the effect of surface steps on the initiation of plastic yield by performing nanoindenrations as a function of separation between the probe and neighboring steps. The mean stress at yield was 30%-45% lower at a step than in regions foe of surface defects. In addition, the spatial extent of the step's influence was found to be approximately 3 times the contact radius at the yield threshold, suggesting that yield processes are not limited to the region in contact with the indenter. C1 Sandia Natl Labs, Surface & Interface Sci Dept, Albuquerque, NM 87185 USA. Sandia Natl Labs, Surface Chem Dept, Livermore, CA 94551 USA. RP Kiely, JD (reprint author), Sandia Natl Labs, Surface & Interface Sci Dept, POB 5800, Albuquerque, NM 87185 USA. NR 16 TC 81 Z9 82 U1 0 U2 18 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 NOV 16 PY 1998 VL 81 IS 20 BP 4424 EP 4427 DI 10.1103/PhysRevLett.81.4424 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CY UT WOS:000077011300037 ER PT J AU Schulthess, TC Butler, WH AF Schulthess, TC Butler, WH TI Consequences of spin-flop coupling in exchange biased films SO PHYSICAL REVIEW LETTERS LA English DT Article ID PERMALLOY/COO INTERFACES; ANISOTROPY; BILAYERS AB Using a microscopic Heisenberg model which includes magnetostatic interactions, the Landau-Lifshitz-Gilbert equation of motion is solved in order to study several magnetic properties of ferromagnetic/antiferromagnetic bilayers. For perfectly flat interfaces, it is shown that spin-flop coupling does not lead to exchange bias as has been proposed, but rather gives rise to a uniaxial anisotropy which in turn causes the large coercivities observed in exchange biased films. The introduction of interfacial defects leads to exchange bias of the coned order of magnitude. [S0031-9007(98)07656-X]. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Schulthess, TC (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 13 TC 409 Z9 419 U1 6 U2 63 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 NOV 16 PY 1998 VL 81 IS 20 BP 4516 EP 4519 DI 10.1103/PhysRevLett.81.4516 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CY UT WOS:000077011300060 ER PT J AU Mineev-Weinstein, M AF Mineev-Weinstein, M TI Comment on "Selection of the Saffman-Taylor finger width in the absence of surface tension: An exact result" - Mineev-Weinstein replies SO PHYSICAL REVIEW LETTERS LA English DT Article C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Mineev-Weinstein, M (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, MS-B213, Los Alamos, NM 87545 USA. NR 6 TC 3 Z9 3 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 16 PY 1998 VL 81 IS 20 BP 4529 EP 4529 DI 10.1103/PhysRevLett.81.4529 PG 1 WC Physics, Multidisciplinary SC Physics GA 139CY UT WOS:000077011300064 ER PT J AU Liska, R Wendroff, B AF Liska, R Wendroff, B TI Composite schemes for conservation laws SO SIAM JOURNAL ON NUMERICAL ANALYSIS LA English DT Article DE composite schemes; conservation laws; hyperbolic systems; Lax-Wendroff scheme; Lax-Friedrichs scheme; two-dimensional Riemann problem ID GAS-DYNAMICS; FLUX AB Global composition of several time steps of the two-step Lax-Wendroff scheme followed by a Lax-Friedrichs step seems to enhance the best features of both, although it is only first order accurate. We show this by means of some examples of one-dimensional shallow water flow over an obstacle. In two dimensions we present a new version of Lax-Friedrichs and an associated second order predictor-corrector method. Composition of these schemes is shown to be effective and efficient for some two-dimensional Riemann problems and for Noh's infinite strength cylindrical shock problem. We also show comparable results for composition of the predictor-corrector scheme with a modified second order accurate weighted essentially nonoscillatory (WENO) scheme. That composition is second order but is more efficient and has better symmetry properties than WENO alone. For scalar advection in two dimensions the optimal stability of the new predictor-corrector scheme is shown using computer algebra. We also show that the generalization of this scheme to three dimensions is unstable, but by using sampling we are able to show that the composites are suboptimally stable. C1 Czech Tech Univ, Fac Nucl Sci & Phys Engn, CR-11519 Prague 1, Czech Republic. Los Alamos Natl Lab, Gro T7, Los Alamos, NM 87544 USA. RP Czech Tech Univ, Fac Nucl Sci & Phys Engn, Brehova 7, CR-11519 Prague 1, Czech Republic. EM liska@siduri.fjfi.cvut.cz; bbw@lanl.gov RI Liska, Richard/C-3142-2009 OI Liska, Richard/0000-0002-6149-0440 NR 22 TC 74 Z9 74 U1 1 U2 2 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 USA SN 0036-1429 EI 1095-7170 J9 SIAM J NUMER ANAL JI SIAM J. Numer. Anal. PD NOV 16 PY 1998 VL 35 IS 6 BP 2250 EP 2271 DI 10.1137/S0036142996310976 PG 22 WC Mathematics, Applied SC Mathematics GA 139EY UT WOS:000077016000007 ER PT J AU Bryan, JC AF Bryan, JC TI cis-syn-cis-dicyclohexano-18-crown-6 sodium perrhenate SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID CRYSTAL-STRUCTURES; ETHER COMPLEXES AB The effect of the anion in a crown ether-cation structure is examined by comparing the structure of [{Na(C20H36O6)}(ReO4)] with one containing the same crown ether and cation, but a different anion. The title compound shows that the crown ether does not form an ideal cavity for sodium, as the Na-O bond lengths vary from 2.470(4) (O3) to 2.863 (4) Angstrom (O1). C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Bryan, JC (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 14 TC 6 Z9 6 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 NOV 15 PY 1998 VL 54 BP 1569 EP 1571 DI 10.1107/S0108270198007422 PN 11 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 148NJ UT WOS:000077537400008 ER PT J AU Bryan, JC Perry, MC Arterburn, JB AF Bryan, JC Perry, MC Arterburn, JB TI Trichlorooxo(triphenylphosphine)(triphenylphospkine oxide)rhenium(V) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID RHENIUM-CATALYZED OXIDATION; SULFOXIDE AB The title complex, [ReCl3O(C18H15OP)(C18H15P)], is produced in a reaction between [Re(O)Cl-3(PPh3)(2)] and ethyl 2-hydroxymethyl sulfoxide, The structure is compared to that of [Re(O)Cl-3(PPhEt2)(OPPhEt2)]. The Re-Cl distances are shorter [2.361(2)-2.384 (2) Angstrom] and the Re-P distance is longer [2.506(2) Angstrom] in the title complex. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. New Mexico State Univ, Dept Chem, Las Cruces, NM 88003 USA. RP Bryan, JC (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 14 TC 8 Z9 8 U1 0 U2 1 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 NOV 15 PY 1998 VL 54 BP 1607 EP 1608 DI 10.1107/S010827019800818X PN 11 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 148NJ UT WOS:000077537400026 ER PT J AU Bryan, JC Lavis, JL Sachleben, RA AF Bryan, JC Lavis, JL Sachleben, RA TI Highly rigid crown ether fragments: phenyl and cyclohexyl catechol ethers SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID CHEMISTRY AB The structures of 1,2-bis(o-nitrophenoxy)benzene [(1), C18H12N2O6], 2,2'-o-phenylenedioxybis(phenylamine) [(2), C18H16N2O2] and meso-2,2'-o-phenylenedioxybis(cyclohexanol) [(3), C18H26O4], potential precursors for rigid crown ether molecules, are presented. Each structure displays hydrogen bonding, Compound (1) exhibits weak C-H ... O interactions, while (2) and (3) display extensive E-H ... E and E-H ...pi (E = N, O) bonding. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Bryan, JC (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 16 TC 7 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 NOV 15 PY 1998 VL 54 BP 1662 EP 1666 DI 10.1107/S0108270198006490 PN 11 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 148NJ UT WOS:000077537400048 ER PT J AU Leung, APK Chan, WT Mao, XL Russo, RE AF Leung, APK Chan, WT Mao, XL Russo, RE TI Influence of gas environment on picosecond laser ablation sampling efficiency and ICP conditions SO ANALYTICAL CHEMISTRY LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; EMISSION; SPECTROSCOPY; VAPORIZATION; ATMOSPHERE; EXCITATION; IONS AB The effects of gas atmosphere on inductively coupled plasma excitation characteristics and picosecond laser ablation sampling are studied for enhancing atomic emission spectroscopy sensitivity. Five noble gases (He, Ne, Ar, Kr, Xe) were used in the laser ablation sampling chamber. The noble gases significantly influence the ICP excitation characteristics and the laser ablation sampling efficiency. There is an enhancement in ICP emission intensity for laser sampling in He and Ne and a decrease for Kr and Xe relative to Ar. Plasma shielding is a possible mechanism to explain the gas effects, as the behavior of laser sampling correlates with the ionization potential of the gas, The significant improvement in AES using He as the sample chamber gas is beneficial to chemical analysis, especially for trace analysis, which requires high sensitivity. C1 Univ Hong Kong, Dept Chem, Hong Kong, Hong Kong. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Russo, RE (reprint author), Univ Hong Kong, Dept Chem, Pokfulam Rd, Hong Kong, Hong Kong. NR 28 TC 23 Z9 24 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 15 PY 1998 VL 70 IS 22 BP 4709 EP 4716 DI 10.1021/ac980336f PG 8 WC Chemistry, Analytical SC Chemistry GA 138ZU UT WOS:000077003600010 ER PT J AU Dadoo, R Zare, RN Yan, C Anex, DS AF Dadoo, R Zare, RN Yan, C Anex, DS TI Advances in capillary electrochromatography: Rapid and high-efficiency separations of PAHs SO ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 1997 Pittsburgh Conference CY MAR 16-21, 1997 CL ATLANTA, GEORGIA ID LIQUID-CHROMATOGRAPHY; PACKED CAPILLARIES; MASS-SPECTROMETRY; ELECTROPHORESIS; COLUMNS; PHASE; PERFORMANCE; FLOW; INJECTION; INTERFACE AB Capillary columns packed electrokinetically with 1.5-mu m nonporous octadecylsilica particles are used to achieve rapid separations with high efficiencies. A mixture containing five polycyclic aromatic hydrocarbons (PAHs) as test compounds is separated in less than 5 s with 28 kV applied to a column with a packed length of 6.5cm (10 cm total length). A sample containing 16 PAHs (classified as priority pollutants by the U.S. Environmental Protection Agency) is isocratically separated in under 10 min by using longer columns (15-30 cm). Separation efficiencies greater than 700 000 theoretical plates/m are obtained when detection (via W-excited laser-induced fluorescence) is performed on the packed portion of the capillary. The outlet frit is observed to play an important role in determining column efficiency. The optimum now rate for best separation efficiency occurs at similar to 2 mm/s. The run-to-run reproducibility of the peak retention times on a single column is better than 1% (relative standard deviation). C1 Stanford Univ, Dept Chem, Stanford, CA 94305 USA. Unimicro Technol Inc, Pleasanton, CA 94566 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Anex, DS (reprint author), Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RI Zare, Richard/A-8410-2009 NR 41 TC 74 Z9 78 U1 0 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 15 PY 1998 VL 70 IS 22 BP 4787 EP 4792 DI 10.1021/ac9803028 PG 6 WC Chemistry, Analytical SC Chemistry GA 138ZU UT WOS:000077003600021 ER PT J AU Nordahl, TE Stein, MB Benkelfat, C Semple, WE Andreason, P Zametkin, A Uhde, TW Cohen, RM AF Nordahl, TE Stein, MB Benkelfat, C Semple, WE Andreason, P Zametkin, A Uhde, TW Cohen, RM TI Regional cerebral metabolic asymmetries replicated in an independent group of patients with panic disorder SO BIOLOGICAL PSYCHIATRY LA English DT Article DE panic disorder; regional cerebral glucose metabolism; hemispheric asymmetries ID OBSESSIVE-COMPULSIVE DISORDER; POSITRON EMISSION TOMOGRAPHY; GLUCOSE-UTILIZATION; PREFRONTAL CORTEX; BLOOD-FLOW; DEPRESSION; ANXIETY; RATES; ADULTS AB Background: Abnormal left/right (L/R) hemispheric ratios of regional cerebral glucose metabolic rates (rCMRglc) (hippocampus and inferior prefrontal cortex) have been noted in unmedicated panic disorder patients, Methods: An independent group of panic disorder patients placed on imipramine was studied with positron-emission tomography, testing for evidence of normalization versus persistence of the abnormal rCMRglc ratios, Differences in orbital frontal rCMRglc values between the imipramine-treated and the previously reported unmedicated panic disorder patients were tested examining for evidence that the differences would resemble those noted in obsessive-compulsive disorder (OCD) patients treated with clomipramine. Results: We found the same abnormally low UR hippocampal and posterior inferior prefrontal rCMRglc ratios in the imipramine-treated panic disorder patients, In addition, we found posterior orbital frontal rCMRglc decreases in the imipramine-treated panic disorder patients compared with the unmedicated panic disorder patients, Conclusions: These abnormal asymmetries found in unmedicated panic disorder patients and now, in imipramine-treated panic disorder patients may reflect a trait abnormality, The orbital frontal rCMRglc differences between the imipramine-treated and unmedicated patients are similar to changes noted in OCD patients treated with clomipramine and may reflect direct or indirect effects of imipramine treatment in panic disorder patients, (C) 1998 Society of Biological Psychiatry. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. Univ Calif Davis, Med Ctr, Dept Psychiat, Sacramento, CA 95817 USA. Napa State Hosp, Napa, CA USA. Univ Calif San Diego, Dept Psychiat, La Jolla, CA 92093 USA. McGill Univ, Dept Psychiat, Neurobiol Psychiat Unit, Montreal, PQ, Canada. Case Western Reserve Univ, Dept Psychiat, Cleveland, OH 44106 USA. US FDA, Rockville, MD 20857 USA. NIMH, Bethesda, MD 20892 USA. Wayne State Univ, Dept Psychiat, Detroit, MI USA. RP Nordahl, TE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, MS 55-121,1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Nordahl, Thomas/J-7643-2013 OI Nordahl, Thomas/0000-0002-8627-0356 NR 30 TC 50 Z9 53 U1 1 U2 2 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 USA SN 0006-3223 J9 BIOL PSYCHIAT JI Biol. Psychiatry PD NOV 15 PY 1998 VL 44 IS 10 BP 998 EP 1006 DI 10.1016/S0006-3223(98)00026-2 PG 9 WC Neurosciences; Psychiatry SC Neurosciences & Neurology; Psychiatry GA 137WA UT WOS:000076938700008 PM 9821564 ER PT J AU Gee, SL Parra, M Willig, T Hou, V Chan, N Wu, M Conboy, JG AF Gee, SL Parra, M Willig, T Hou, V Chan, N Wu, M Conboy, JG TI Alternative splicing of protein 4.1 exon 16 is regulated in part by downstream intron elements. SO BLOOD LA English DT Meeting Abstract C1 Univ Calif Berkeley, Div Life Sci, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1998 VL 92 IS 10 SU 1 MA 6 BP 5A EP 5A PN 1 PG 1 WC Hematology SC Hematology GA 141AW UT WOS:000077121300007 ER PT J AU Gilligan, DM Lozovatsky, L Mohandas, N Gwynn, B Peters, LL AF Gilligan, DM Lozovatsky, L Mohandas, N Gwynn, B Peters, LL TI The beta-adducin knockout mouse bas spherocytic anemia and loss of alpha-adducin from RBC ghosts. SO BLOOD LA English DT Meeting Abstract C1 Yale Univ, New Haven, CT USA. Lawrence Berkeley Lab, Berkeley, CA USA. Jackson Lab, Bar Harbor, ME 04609 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1998 VL 92 IS 10 SU 1 MA 1232 BP 301A EP 301A PN 1 PG 1 WC Hematology SC Hematology GA 141AW UT WOS:000077121301224 ER PT J AU de Jong, K Emerson, RK Butler, J Paszty, C Mohandas, N Kuypers, FA AF de Jong, K Emerson, RK Butler, J Paszty, C Mohandas, N Kuypers, FA TI Rapid turnover of red blood cells in sickle cell mice. SO BLOOD LA English DT Meeting Abstract C1 Childrens Hosp, Oakland Res Inst, Oakland, CA 94609 USA. Lawrence Berkeley Lab, Berkeley, CA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1998 VL 92 IS 10 SU 1 MA 1356 BP 331A EP 331A PN 1 PG 1 WC Hematology SC Hematology GA 141AW UT WOS:000077121301348 ER PT J AU Mentzer, W Paszty, C Zhu, Y Turetsky, T Tsai, S Kuypers, F Lee, G Cooper, P Gallagher, P Stevens, M Rubin, E Mohandas, N AF Mentzer, W Paszty, C Zhu, Y Turetsky, T Tsai, S Kuypers, F Lee, G Cooper, P Gallagher, P Stevens, M Rubin, E Mohandas, N TI Stomatocytosis is absent in "stomatin" deficient murine red cells. SO BLOOD LA English DT Meeting Abstract C1 Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA USA. Childrens Hosp Oakland, Oakland, CA USA. Yale Univ, Sch Med, New Haven, CT USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1998 VL 92 IS 10 SU 1 MA 1940 BP 470A EP 470A PN 1 PG 1 WC Hematology SC Hematology GA 141AW UT WOS:000077121301930 ER PT J AU Hawkins, S Man, W Kohwi-Shigematsu, T Skalnik, D AF Hawkins, S Man, W Kohwi-Shigematsu, T Skalnik, D TI Differential binding of the nuclear matrix protein SATB1 to the gp91-phox promoter during myeloid cell differentiation. SO BLOOD LA English DT Meeting Abstract C1 Indiana Univ, Sch Med, Dept Pediat & Biochem,Sect Pediat Hematol Oncol, Herman B Wells Ctr Pediat Res, Indianapolis, IN 46202 USA. Indiana Univ, Sch Med, Dept Mol Biol,Sect Pediat Hematol Oncol, Herman B Wells Ctr Pediat Res, Indianapolis, IN 46202 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1998 VL 92 IS 10 SU 1 MA 2048 BP 497A EP 497A PN 1 PG 1 WC Hematology SC Hematology GA 141AW UT WOS:000077121302038 ER PT J AU Embury, SH Mohandas, N Paszty, C Crnic, L Cooper, P Cheung, ATW AF Embury, SH Mohandas, N Paszty, C Crnic, L Cooper, P Cheung, ATW TI The viscous vicissitudes of in vivo blood flow in the transgenic knockout sickle cell mouse. SO BLOOD LA English DT Meeting Abstract C1 San Francisco Gen Hosp, Dept Med, San Francisco, CA 94110 USA. San Francisco Gen Hosp, Div Hematol, San Francisco, CA 94110 USA. Univ Calif San Francisco, San Francisco, CA 94143 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Dept Life Sci, Berkeley, CA 94720 USA. Univ Calif Davis, Med Ctr, Dept Pathol, Sacramento, CA 95817 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU W B SAUNDERS CO PI PHILADELPHIA PA INDEPENDENCE SQUARE WEST CURTIS CENTER, STE 300, PHILADELPHIA, PA 19106-3399 USA SN 0006-4971 J9 BLOOD JI Blood PD NOV 15 PY 1998 VL 92 IS 10 SU 1 MA 2853 BP 694A EP 694A PN 1 PG 1 WC Hematology SC Hematology GA 141AW UT WOS:000077121302842 ER PT J AU Boscher, D Bourdarie, S Friedel, R Korth, A AF Boscher, D Bourdarie, S Friedel, R Korth, A TI Long term dynamic radiation belt model for low energy protons SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RING CURRENT; ELECTRON; SIMULATIONS; DIFFUSION; TRANSPORT; FIELD; PHASE; CRRES; ION AB A new simple model for equatorialy mirroring protons, based on classical radial diffusion, is used here to understand the global long term dynamics of the ring current ion population. The convection access for low energy particles coming from the plasmasheet is used as a source population. Then magnetospheric acceleration processes are reproduced by using a Kp dependent radial diffusion coefficient. Comparing the results with CRRES satellite energetic ion measurements from the fifteen months of the total mission yields very good quantitative agreement for similar to 80 keV ring-current protons and good qualitative agreement with similar to 300 keV ions. C1 DESP, ONERA, Dept Environm Spatial, F-31055 Toulouse, France. Univ Calif Los Alamos Natl Lab, Los Alamos, NM USA. Max Planck Inst Aeron, D-37189 Katlenburg Lindau, Germany. RP Boscher, D (reprint author), DESP, ONERA, Dept Environm Spatial, POB 4025 2,Av E Belin, F-31055 Toulouse, France. RI Friedel, Reiner/D-1410-2012 OI Friedel, Reiner/0000-0002-5228-0281 NR 14 TC 15 Z9 15 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 NOV 15 PY 1998 VL 25 IS 22 BP 4129 EP 4132 DI 10.1029/1998GL900077 PG 4 WC Geosciences, Multidisciplinary SC Geology GA 139GH UT WOS:000077019300007 ER PT J AU Veith, KF AF Veith, KF TI Comment on "Empirical determination of depth-distance corrections for m(b) and M-w from global seismograph network stations" SO GEOPHYSICAL RESEARCH LETTERS LA English DT Editorial Material AB This paper looks at the bases for the cited depth-distance corrections by Guust Nolet, Steve Krueger, and Robert M. Clouser(Paper 98GL01094, GRL, Vol. 25, No. 9, pp. 1451-1454, May 1, 1998), the historic curves of Gutenberg and Richter, and those given by Veith and Clawson (1972). It discusses the some of the problems associated with the establishment of such curves and suggests modes of strengthening both the current work and potential future work. C1 US Dept Energy, Off Nonproliferat & Natl Secur, Off Res & Dev, Washington, DC 20585 USA. RP Veith, KF (reprint author), US Dept Energy, Off Nonproliferat & Natl Secur, Off Res & Dev, Washington, DC 20585 USA. NR 1 TC 1 Z9 1 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 NOV 15 PY 1998 VL 25 IS 22 BP 4241 EP 4242 DI 10.1029/1998GL900083 PG 2 WC Geosciences, Multidisciplinary SC Geology GA 139GH UT WOS:000077019300035 ER PT J AU Ritchie, B Weatherford, CA AF Ritchie, B Weatherford, CA TI Use of a fast Fourier transform (FFT) 3D time-dependent Schrodinger equation solver in molecular electronic structure SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT International Symposium on Atomic, Molecular, and Condensed Matter Theory at the 38th Annual Sanibel Symposium CY FEB 21-27, 1998 CL ST AUGUSTINE, FLORIDA SP IBM Corp, HyperCube Inc, Q-Chem Inc, Univ Florida AB An implicit split-operator FFT algorithm for the numerical solution of the time-dependent Schrodinger equation is implemented for the electronic structure of H-2(+) and and H-2. The covalent versus separated-atoms behavior is described by two distinct steady states to which the imaginary-time Schrodinger solution evolves for small or large internuclear distances, respectively. (C) 1998 John Wiley & Sons, Inc. C1 Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Weatherford, CA (reprint author), Florida A&M Univ, Dept Phys, Tallahassee, FL 32307 USA. NR 10 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD NOV 15 PY 1998 VL 70 IS 4-5 BP 627 EP 635 PG 9 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 139CN UT WOS:000077010200009 ER PT J AU Butler, LG Maverick, AW Gallegos, CH Goettee, JD Marshall, BR Fowler, CM Rickel, DG Gonzales, JM Tabaka, LJ AF Butler, LG Maverick, AW Gallegos, CH Goettee, JD Marshall, BR Fowler, CM Rickel, DG Gonzales, JM Tabaka, LJ TI Some aspects of data processing for an optical absorption experiment in a pulsed 1000-Tesla magnet SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT International Symposium on Atomic, Molecular, and Condensed Matter Theory at the 38th Annual Sanibel Symposium CY FEB 21-27, 1998 CL ST AUGUSTINE, FLORIDA SP IBM Corp, HyperCube Inc, Q-Chem Inc, Univ Florida DE pulsed magnetic field; Zeeman effect; quadruple metal bonds; octachlorodirhenate AB A procedure is given for the analysis of optical absorption data acquired in the hostile environment of a pulsed 1000-Tesla magnet. (C) 1998 John Wiley & Sons, Inc. C1 Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. Univ Calif Los Alamos Natl Lab, Natl High Magnet Field Lab, Los Alamos, NM 87545 USA. Bechtel Nevada, Los Alamos, NM 87544 USA. Bechtel Nevada, Special Technol Lab, Santa Barbara, CA 93111 USA. RP Butler, LG (reprint author), Louisiana State Univ, Dept Chem, Baton Rouge, LA 70803 USA. RI Butler, Leslie/D-1636-2016 OI Butler, Leslie/0000-0003-1547-608X NR 5 TC 1 Z9 1 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD NOV 15 PY 1998 VL 70 IS 4-5 BP 797 EP 804 PG 8 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 139CN UT WOS:000077010200026 ER PT J AU Boettger, JC AF Boettger, JC TI Relativistic effects on the structural phase stability of molybdenum SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article; Proceedings Paper CT International Symposium on Atomic, Molecular, and Condensed Matter Theory at the 38th Annual Sanibel Symposium CY FEB 21-27, 1998 CL ST AUGUSTINE, FL SP IBM Corp, HyperCube Inc, Q-Chem Inc, Univ Florida DE molybdenum; phase stability; relativity; Douglas-Kroll ID DOUGLAS-KROLL TRANSFORMATION; METALS; MO; ENERGY; CR; 4D AB The body-centered cubic-face-centered cubic (bcc-fcc) structural phase stability of molybdenum (Mo) is studied as a function of volume with both nonrelativistic and scalar-relativistic linear combinations of Gaussian-type orbitals-fitting functions (LCGTO-FF) calculations. It is demonstrated that relativity has a significant, albeit small effect, on the bcc-fcc structural energy difference, which increases with pressure. The scalar-relativistic structural energy difference curve is shown to be in excellent agreement with an earlier scalar-relativistic calculation using the full-potential linear muffin-tin orbital (FP-LMTO) method, clearly demonstrating the ability of the scalar-relativistic LCGTO-FF method to resolve an extremely subtle relativistic effect. It is argued that relativity will tend to delay pressure-induced structural phase transitions that are triggered by electron band reordering. (C) 1998 John Wiley & Sons, Inc. 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 jn@lanl.gov NR 26 TC 3 Z9 3 U1 0 U2 1 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0020-7608 EI 1097-461X J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD NOV 15 PY 1998 VL 70 IS 4-5 BP 825 EP 830 PG 6 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA 139CN UT WOS:000077010200029 ER PT J AU Mathis, JE Goyal, A Lee, DF List, FA Paranthaman, M Christen, DK Specht, ED Kroeger, DM Martin, PM AF Mathis, JE Goyal, A Lee, DF List, FA Paranthaman, M Christen, DK Specht, ED Kroeger, DM Martin, PM TI Biaxially textured YBa2Cu3O7-delta conductors on rolling assisted biaxially textured substrates with critical current densities of 2-3 mA/cm(2) SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS LA English DT Article DE superconductors; pulsed laser deposition; critical current; biaxially textured substrates; RABiTS; X-ray diffraction ID THIN-FILMS; GRAIN-BOUNDARIES; BUFFER LAYERS; SUPERCONDUCTING TAPES; DEPOSITION; DEPENDENCE; BICRYSTALS AB Epitaxial YBa2Cu3O7-delta (YBCO) films with transport critical current densities approaching 3 x 10(6) A/cm(2) (77 K, 0 T) were fabricated using laser ablation of YBCO onto rolling-assisted biaxially textured-substrates (RABiTS) using a combination of thin CeO2 and thick YSZ buffer layers. The configuration of the sample was YBCO (similar to 0.2 mu m)/YSZ (0.7 mu m)/CeO2 (0.05 mu m)Ni (125 mu m). The CeO2 and YSZ buffer layers were deposited using electron-beam evaporation and sputtering, respectively. The temperature window for successful pulsed-laser deposition of YBCO onto RABiTS was found to be between 740 degrees C and 790 degrees C. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Mathis, JE (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Christen, David/A-9709-2008; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531 NR 17 TC 54 Z9 54 U1 0 U2 0 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO, 105, JAPAN SN 0021-4922 J9 JPN J APPL PHYS 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. PD NOV 15 PY 1998 VL 37 IS 11B BP L1379 EP L1382 DI 10.1143/JJAP.37.L1379 PG 4 WC Physics, Applied SC Physics GA 168PF UT WOS:000078700900011 ER PT J AU Cantrell, JH Zhang, XG AF Cantrell, JH Zhang, XG TI Nonlinear acoustic response from precipitate-matrix misfit in a dislocation network SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID HARMONIC-GENERATION AB An analytical model is presented for the effects on the acoustic nonlinearity of the interaction of matrix dislocations with precipitate coherency strains in metallic alloys. The acoustic nonlinearity parameters are shown to depend linearly on the dislocation density, volume fraction of precipitates and precipitate-matrix misfit parameters, and on the fourth power of the dislocation loop length. The model predicts changes in the acoustic nonlinearity parameter associated with the growth of precipitates during the artificial aging of aluminum alloy 2024 that are in good agreement with experimental measurements reported in the literature. [S0021-8979(98)04222-4]. C1 NASA, Langley Res Ctr, Hampton, VA 23681 USA. Oak Ridge Natl Lab, Computat Phys & Engn Div, Oak Ridge, TN 37831 USA. RP Cantrell, JH (reprint author), NASA, Langley Res Ctr, Mail Stop 231, Hampton, VA 23681 USA. NR 12 TC 21 Z9 23 U1 0 U2 11 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 NOV 15 PY 1998 VL 84 IS 10 BP 5469 EP 5472 DI 10.1063/1.368309 PG 4 WC Physics, Applied SC Physics GA 133CP UT WOS:000076669100010 ER PT J AU Simmons, JA Blount, MA Moon, JS Lyo, SK Baca, WE Wendt, JR Reno, JL Hafich, MJ AF Simmons, JA Blount, MA Moon, JS Lyo, SK Baca, WE Wendt, JR Reno, JL Hafich, MJ TI Planar quantum transistor based on 2D-2D tunneling in double quantum well heterostructures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FIELD-EFFECT TRANSISTOR; 2-DIMENSIONAL ELECTRON-SYSTEMS; ROOM-TEMPERATURE; DEVICES; DIODES; PARALLEL; TRANSCONDUCTANCE; REALIZATION; GROWTH; CELL AB We report on our work on the double electron layer tunneling transistor (DELTT), based on the gate control of two-dimensional-two-dimensional (2D-2D)! tunneling in a double quantum well heterostructure. While previous quantum transistors have typically required tiny laterally defined features, by contrast the DELTT is entirely planar and can be reliably fabricated in large numbers. We use a novel epoxy-bond-and-stop-etch flip-chip process, whereby submicron gating on opposite sides of semiconductor epitaxial layers as thin as 0.24 mu m can be achieved. Because both electron layers in the DELTT are 2D, the resonant tunneling features are unusually sharp, and can be easily modulated with one or more surface gates. We demonstrate DELTTs with peak-to-valley ratios in the source-drain I-V curve of order 20:1 below 1 K. Both the height and position of the resonant current peak can be controlled by gate voltage over a wide range. DELTTs with larger subband energy offsets (similar to 21 meV) exhibit characteristics that are nearly as good at 77 K, in good agreement with our theoretical calculations. Using these devices, we also demonstrate bistable memories operating at 77 K. Finally, we briefly discuss the prospects for room temperature operation, increases in gain and high speed. (C) 1998 American Institute of Physics. [S0021-8979(98)06522-0]. C1 Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP Simmons, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 39 TC 37 Z9 37 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 NOV 15 PY 1998 VL 84 IS 10 BP 5626 EP 5634 DI 10.1063/1.368610 PG 9 WC Physics, Applied SC Physics GA 133CP UT WOS:000076669100036 ER PT J AU Korte, BJ Pecharsky, VK Gschneidner, KA AF Korte, BJ Pecharsky, VK Gschneidner, KA TI The correlation of the magnetic properties and the magnetocaloric effect in (Gd1-xErx) NiAl alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID REFRIGERATOR; CYCLE AB A study of the magnetic properties of several (Gd1-xErx)NiAl alloys (where x = 0, 0.30, 0.40, 0.46, 0.50, 0.55, 0.60, 0.80, and 1.00) was undertaken using both ac and dc magnetic and heat capacity measurements in an attempt to understand the table-like magnetocaloric effect previously observed in (Gd0.54Er0.46)NiAl. Results indicate the presence of both antiferromagnetic and ferromagnetic ordering processes in all alloys containing Gd. For ErNiAl, a metamagnetic transition from an antiferromagnetic ground state was observed. Within each alloy, several magnetic transitions occur over a temperature range from 10 K [in (Gd0.20Er0.80)NiAl] up to 35 K (in GdNiAl), with all but the lowest temperature transition shifting to higher temperatures with increasing Gd content. The change in magnetic entropy (Delta S-mag) induced by a change in field is observed to peak around the Neel temperature for ErNiAl while gradually broadening and shifting toward the Curie temperature as the Gd content is increased. For Gd-rich alloys, a significant contribution to Delta S-mag is observed at both the low and high temperature transitions, resulting in a rounded, skewed caret-like temperature profile of the magnetocaloric effect. Factors, which are believed to contribute to this effect, include the presence and temperature spacing of multiple zero-field transitions, which most likely result from competing anisotropy and exchange interactions within a frustrated hexagonal spin lattice. This leads to broad peaks in the magnetic heat capacity that span several transition temperatures, providing for a substantial Delta S-mag over an extended temperature range. This characteristic is desired for application to magnetic refrigeration, where certain thermodynamic cycles (e. g., Ericsson cycle) require specific temperature profiles of the magnetocaloric effect in refrigerant materials (e. g., a constant change in magnetic entropy as a function of temperature within the region of cooling). In general, the best materials are those which supply the maximum amount of cooling over the widest temperature range. (C) 1998 American Institute of Physics. [S0021-8979(98)03122-3]. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Korte, BJ (reprint author), Univ Colorado, Dept Chem, Boulder, CO 80309 USA. NR 21 TC 91 Z9 95 U1 2 U2 28 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 NOV 15 PY 1998 VL 84 IS 10 BP 5677 EP 5685 DI 10.1063/1.368830 PG 9 WC Physics, Applied SC Physics GA 133CP UT WOS:000076669100046 ER PT J AU Tav, C Datskos, PG Pinnaduwage, LA AF Tav, C Datskos, PG Pinnaduwage, LA TI Electron attachment to boron trichloride SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CROSS-SECTIONS; ENERGY; EXCITATION; PLASMAS; BCL3 AB Low-energy electron attachment to BCl3 was measured using an electron swarm technique. The parent negative ion, BCl3- was observed within a narrow electron range close to thermal energy. Previous negative ion measurements in BCl3 discharges, which yielded seemingly inconsistent results, can be shown to be self-consistent based on the present observations. (C) 1998 American Institute of Physics. [S0021-8979(98)01722-8]. C1 Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Pinnaduwage, LA (reprint author), Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. EM llp@ornl.gov NR 17 TC 4 Z9 4 U1 0 U2 2 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 NOV 15 PY 1998 VL 84 IS 10 BP 5805 EP 5807 DI 10.1063/1.368846 PG 3 WC Physics, Applied SC Physics GA 133CP UT WOS:000076669100070 ER PT J AU Salsbury, FR Harris, RA AF Salsbury, FR Harris, RA TI The origin of the magnetic-field-dependent quadrupolar splitting SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article AB We confirm that the recently discovered field-dependent nuclear quadrupolar splitting of Xe-131 [T. Meersmann and M. Haake, Phys. Rev. Lett. 81, 1211 (1998)] arises from a distortion of the electron density due to the applied magnetic field. This distortion depends both linearly and quadratically on the applied field. The existence of the former is due to the coupling to the field and the nuclear spin. The latter is a manifestation of the quadratic Zeeman effect. In addition to confirming the order of magnitude for the observed effect, we show that there should be an asymmetry introduced in the spectra due to the linear coupling with the nuclear spin. This effect has not been seen experimentally. (C) 1998 American Institute of Physics. [S0021-9606(98)01643-2]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Salsbury, FR (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Salsbury, Freddie/A-5923-2008 NR 6 TC 5 Z9 5 U1 1 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 NOV 15 PY 1998 VL 109 IS 19 BP 8338 EP 8341 DI 10.1063/1.477627 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 139AJ UT WOS:000077005000023 ER PT J AU Morris, GM Goodsell, DS Halliday, RS Huey, R Hart, WE Belew, RK Olson, AJ AF Morris, GM Goodsell, DS Halliday, RS Huey, R Hart, WE Belew, RK Olson, AJ TI Automated docking using a Lamarckian genetic algorithm and an empirical binding free energy function SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article DE automated docking; binding affinity; drug design; genetic algorithm; flexible small molecule protein interaction ID DIHYDROFOLATE-REDUCTASE; LIGAND INTERACTIONS; MOLECULAR DESIGN; HIV-1 PROTEASE; FLEXIBLE LIGANDS; IONIZABLE GROUPS; NUCLEIC-ACIDS; FORCE-FIELD; PROTEINS; INHIBITORS AB A novel and robust automated docking method that predicts the bound conformations of flexible Ligands to macromolecular targets has been developed and tested, in combination with a new scoring function that estimates the free energy change upon binding. Interestingly, this method applies a Lamarckian model of genetics, in which environmental adaptations of an individual's phenotype are reverse transcribed into its genotype and become heritable traits (sic). We consider three search methods, Monte Carlo simulated annealing, a traditional genetic algorithm, and the Lamarckian genetic algorithm, and compare their performance in dockings of seven protein-ligand test systems having known three-dimensional structure. We show that both the traditional and Lamarckian genetic algorithms can handle ligands with more degrees of freedom than the simulated annealing method used in earlier versions of AUTODOCK, and that the Lamarckian genetic algorithm is the most efficient, reliable, and successful of the three. The empirical free energy function was calibrated using a set of 30 structurally known protein-ligand complexes with experimentally determined binding constants. Linear regression analysis of the observed binding constants in terms of a wide variety of structure-derived molecular properties was performed. The final model had a residual standard error of 9.11 kJ mol(-1) (2.177 kcal mol(-1)) and was chosen as the new energy function. The new search methods and empirical free energy function are available in AUTODOCK, version 3.0. (C) 1998 John Wiley & Sons, Inc. C1 Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Hewlett Packard Co, San Diego, CA USA. Sandia Natl Labs, Dept Appl Math, Albuquerque, NM 87185 USA. Univ Calif San Diego, Dept Comp Sci & Engn, La Jolla, CA 92093 USA. RP Olson, AJ (reprint author), Scripps Res Inst, Dept Mol Biol, MB-5,10550 N Torrey Pines Rd, La Jolla, CA 92037 USA. EM olson@scripps.edu OI Morris, Garrett/0000-0003-1731-8405 NR 79 TC 5676 Z9 5821 U1 44 U2 335 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0192-8651 J9 J COMPUT CHEM JI J. Comput. Chem. PD NOV 15 PY 1998 VL 19 IS 14 BP 1639 EP 1662 DI 10.1002/(SICI)1096-987X(19981115)19:14<1639::AID-JCC10>3.0.CO;2-B PG 24 WC Chemistry, Multidisciplinary SC Chemistry GA 131NC UT WOS:000076581300010 ER PT J AU Hofstee, C Oostrom, M Dane, JH Walker, RC AF Hofstee, C Oostrom, M Dane, JH Walker, RC TI Infiltration and redistribution of perchloroethylene in partially saturated, stratified porous media SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE DNAPL; nonspreading; gamma radiation; numerical simulator (STOMP); multifluid flow ID NONAQUEOUS-PHASE LIQUID; MODEL DEVELOPMENT; ORGANIC-COMPOUNDS; NUMERICAL-MODEL; MULTIPHASE FLOW; TRANSPORT; WATER; VERIFICATION; VALIDATION; DRAINAGE AB Contamination of the subsurface by nonaqueous phase liquids (NAPLs) is a widespread problem. To investigate the behavior of a nonspreading, dense NAPL (DNAPL) in the vadose zone, we conducted perchloroethylene (PCE) infiltration experiments in nominally 1- and 2-dimensional (D), stratified porous media. In addition, the usefulness and limitations of a multifluid flow simulator to describe PCE infiltration and redistribution under the experimental conditions were tested. The physical simulations were conducted in a column (1-D) and a flow container (2-D) which were packed with two distinct layers of coarse-grained sand and a fine-grained sand layer in between. Volumetric water and PCE contents were determined with a fully automated dual-energy gamma radiation system. While migrating through the drier parts of the coarse-grained sand layers, PCE appeared to wet the water-air interface rather than displacing any water. In the wetter parts of the porous medium, PCE displaced water and behaved as a true nonwetting fluid. PCE showed a limited response to gradients in capillary pressure and rather high values for the volumetric PCE content were measured in the fine-grained sand layers. This was attributed to the nonspreading nature of PCE. The multifluid flow simulator appeared to predict the initial PCE movement in the vadose zone reasonably well. However, the model was not capable of predicting the final amounts of PCE retained in either the unsaturated of saturated part of the flow domain, mainly because the simulator does not consider the nonspreading flow behavior of NAPLs. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Auburn Univ, Dept Agron & Soils, Auburn, AL 36849 USA. Pacific NW Natl Lab, Environm Technol Div, Richland, WA USA. Auburn Univ, Dept Civil Engn, Auburn, AL 36849 USA. RP Dane, JH (reprint author), ROK Technol, N Charleston, SC, Brazil. NR 44 TC 30 Z9 32 U1 1 U2 3 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 NOV 15 PY 1998 VL 34 IS 4 BP 293 EP 313 DI 10.1016/S0169-7722(98)00101-6 PG 21 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 148GV UT WOS:000077497600001 ER PT J AU Shook, GM Pope, GA Kostarelos, K AF Shook, GM Pope, GA Kostarelos, K TI Prediction and minimization of vertical migration of DNAPLS using surfactant enhanced aquifer remediation at neutral buoyancy SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE DNAPL; remediation; surfactants; vertical migration; buoyancy ID RESIDUAL TETRACHLOROETHYLENE AB Surfactant enhanced aquifer remediation (SEAR) had previously been thought to require a capillary barrier below the contaminated zone to prevent the vertical migration of a microemulsion containing solubilized DNAPL. This paper shows the vertical migration of the dense microemulsion is described and predicted by the value of three dimensionless scaling groups. Embedded within these scaling groups are four design parameters. The value of these parameters can be manipulated in order to reduce the amount of vertical migration anticipated for a given remediation design. Plots have been constructed that illustrate the relationship between vertical migration and the value of the scaling groups; such plots can be used to predict vertical migration and to determine appropriate screen intervals of extraction wells to ensure full capture of the contaminants. This predictive capability has been verified in laboratory experiments. Predicted migration of the microemulsion agreed within about 2% of that observed Development of the scaling groups is presented, remediation design implications are discussed, and laboratory verification is shown. Additional discussion of the laboratory work is given in a companion paper [Kostarelos, K., Pope, G.A., Rouse, B.A., Shook, G.M., 1998. A new concept: the use of neutrally-buoyant microemulsions for DNAPL remediation, J. Contam. Hydro., this edition]. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Idaho Natl Lab, Idaho Falls, ID 83415 USA. Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. Univ Texas, Dept Civil Engn, Austin, TX 78712 USA. RP Shook, GM (reprint author), Idaho Natl Lab, Idaho Falls, ID 83415 USA. EM ook@inel.gov; gary_pope@pe.utexas.edu; dino_k@mail.utexas.edu OI Kostarelos, Konstantinos/0000-0003-0303-6634 NR 24 TC 17 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 EI 1873-6009 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD NOV 15 PY 1998 VL 34 IS 4 BP 363 EP 382 DI 10.1016/S0169-7722(98)00090-4 PG 20 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 148GV UT WOS:000077497600004 ER PT J AU Kostarelos, K Pope, GA Rouse, BA Shook, GM AF Kostarelos, K Pope, GA Rouse, BA Shook, GM TI A new concept: the use of neutrally-buoyant microemulsions for DNAPL remediation SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article DE groundwater; microemulsion; remediation; surfactant; DNAPL; contaminants ID RESIDUAL TETRACHLOROETHYLENE; SURFACTANT; SELECTION; AQUIFERS; RECOVERY; PHASE; OIL AB Even in the absence of mobilization of dense nonaqueous phase liquid (DNAPL), the microemulsion that forms when the surfactant solubilizes a dense contaminant such as trichloroethylene will be more dense than water and tends to migrate downward. This paper addresses the issue of migration with a new concept: surfactant enhanced aquifer remediation at neutral buoyancy. Laboratory results of surfactant remediation in two-dimensional model aquifers show that downward migration of microemulsion containing solubilized dense contaminants can be reduced to an acceptable level, even in the absence of capillary barriers in the aquifer. One model experiment was designed to exhibit a small degree of vertical migration and full capture of the microemulsion at the extraction well. The second experiment was designed to demonstrate the effect of large buoyancy forces that lead to excessive downward migration of the microemulsion. Density measurements of aqueous solutions containing sodium dihexyl sulfosuccinate surfactant, isopropanol, trichloroethylene, and sodium chloride are presented. A companion paper presents the results of the flow and transport calculations needed for this approach to surfactant flooding. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Texas, Dept Civil Engn, Austin, TX 78712 USA. Univ Texas, Dept Petr & Geosyst Engn, Austin, TX 78712 USA. Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Pope, GA (reprint author), Univ Texas, Dept Civil Engn, Austin, TX 78712 USA. EM dino_k@mail.utexas.edu; gary_pope@pe.utexas.edu; bruce_rouse@pe.utexas.edu; ook@inel.gov OI Kostarelos, Konstantinos/0000-0003-0303-6634 NR 24 TC 28 Z9 28 U1 0 U2 2 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 NOV 15 PY 1998 VL 34 IS 4 BP 383 EP 397 DI 10.1016/S0169-7722(98)00091-6 PG 15 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA 148GV UT WOS:000077497600005 ER PT J AU Karen, P Woodward, PM AF Karen, P Woodward, PM TI Liquid-mix disorder in crystalline solids: ScMnO3 SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article DE scandium manganese oxide; liquid-mix disorder; metastable; ordering kinetics; synchrotron X-ray diffraction; crystallite size; micro-strain analysis ID MAGNETIC-PROPERTIES; X-RAY; DIFFRACTION AB The liquid-mix citrate synthesis of ScMnO3, when conducted at temperatures below approximately 700 degrees C, leads to the formation of a (nano)crystalline oxide with the liquid-mix disorder of the metal atoms preserved. The disordered phase has an excess of oxygen atoms over three per formula, implying the presence of both Mn3+ and Mn4+. Synchrotron X-ray powder diffraction reveals two phases (domains) with nearly identical lattices in the liquid-mix sample; a bixbyite-type phase (as adopted by Sc2O3 and Mn2O3) and a defect fluorite-type phase. Examinations of the unit-cell parameters indicate that most if not all of the Mn4+ and excess oxygen are incorporated into the fluorite-type phase, Annealing at temperatures higher than 700 degrees C induces a rapid transformation of this phase mixture into a single-phase product represented by the stable hexagonal modification of ScMnO3. Both components of the liquid-mix oxide, viz, the metastable bixbyite-type phase and the oxidation-stabilized fluorite-type phase, exhibit high strain attributed to the size imbalance of the constituent metal atoms. Transformation into the stable ordered hexagonal phase is accompanied by an order of magnitude decrease in the micro-strain and a dramatic increase in the crystallite size, The kinetics of the ordering phase transition have been investigated using conventional X-ray powder diffraction techniques. Disordered (Sc1-xMnx)(2)O3+delta solid solutions, synthesized analogously by the liquid-mix technique, transform under exsolution of ScMnO3 into stable solid solutions, The thermodynamically stable solid-solution limits are estimated to be (Sc0.85Mn0.15)(2)O-3 and (Sc0.10Mn0.90)(2)O-3 at 1000 degrees C for the scandium and manganese rich ends of the phase diagram, respectively. (C) 1998 Academic Press. C1 Univ Oslo, Dept Chem, N-0315 Oslo, Norway. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Woodward, PM (reprint author), Univ Oslo, Dept Chem, POB 1033, N-0315 Oslo, Norway. RI Karen, Pavel/A-9062-2008 OI Karen, Pavel/0000-0003-2937-6477 NR 36 TC 35 Z9 35 U1 2 U2 11 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 NOV 15 PY 1998 VL 141 IS 1 BP 78 EP 88 DI 10.1006/jssc.1998.7918 PG 11 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 146YU UT WOS:000077462100009 ER PT J AU Zhao, YS AF Zhao, YS TI Crystal chemistry and phase transitions of perovskite in P-T-X space: Data for (KxNa1-x)MgF3 perovskites SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID NAMGF3 PEROVSKITE; THERMAL-EXPANSION; DIFFRACTION; RADIATION AB We report a high-resolution synchrotron X-ray powder diffraction study on (KxNa1-x)MgF3 perovskites at high pressures and temperatures. The crystal structure of the perovskite transforms reversibly from orthorhombic (Pbnm) to tetragonal (P4/mbm) to cubic (Pm3m) with change of pressure and temperature and also with K+ concentration. The tilt angle of the MgF6 octahedral framework decreases continually and the octahedral Mg-F bond length increases slightly with increasing temperature. Correspondingly, at high pressures, the tilting angles increase slightly and the shortening of the Mg-F bond length is the dominant compression mechanism. Both octahedral tilting and bond length decrease with increasing K+ participation. We have monitored superlattice diffraction associated with in-phase and antiphase octahedral tiltings in situ and in real time in P-T-X space. The intensities of the superlattice diffraction peaks decrease quickly toward zero with increasing temperature and/or K+ concentration. Meanwhile, the doublet and triplet diffraction peaks, which directly reflect the dimensional differences of the a, b, and c axes, converge continuously and finally coalesce into single peaks as the temperature reaches T-c and/or the K+ concentration reaches X-c, The transition temperatures are plotted as a function of pressure (T-c-P), and as a function of composition (T-c-X), The structural phase transitions in (K,Na) MgF3 perovskites are driven by two order parameters, which are represented by the octahedral tiltings theta = (phi(x)(-), phi(y)(-) 0) and phi = (0, 0, phi(z)(+)). The strong coupling between these two order parameters drives the end-member NaMgF3 perovskite to transform directly from the orthorhombic to cubic phase at temperature T-c=1038 K. Such direct orthorhombic-cubic phase transition remains unbroken even at pressures up to 10 GPa, However, with increasing incorporation of larger K+ cations into the crystal structure, the interaction between the octahedral tiltings was successively decoupled and the purely intermediate tetragonal phase thus appeared around X similar to 35%, The crystal structure of the (KxNa1-x) MgF3 perovskites eventually becomes cubic at X similar to 40%. (C) 1998 Academic Press. C1 Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. RP Zhao, YS (reprint author), Los Alamos Natl Lab, LANSCE, MS-H805, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012 NR 29 TC 26 Z9 27 U1 0 U2 9 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0022-4596 EI 1095-726X J9 J SOLID STATE CHEM JI J. Solid State Chem. PD NOV 15 PY 1998 VL 141 IS 1 BP 121 EP 132 DI 10.1006/jssc.1998.7927 PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 146YU UT WOS:000077462100015 ER PT J AU Andersen, EK Andersen, IGK Norby, P Hanson, JC AF Andersen, EK Andersen, IGK Norby, P Hanson, JC TI Kinetics of oxidation of fuel cell cathode materials lanthanum strontium Manganates(III)(IV) at actual working conditions: In situ powder diffraction studies SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID MANGANITE; NEUTRON AB Time resolved synchrotron X-ray powder diffraction methods have been used to study the kinetics of oxidation of lanthanum strontium manganates(III, IV) in a Bow of oxygen. The process studied is La1-xSrxMnO3.00+ delta/2O(2) <-> La1-xSrxMnO3.00+delta (for x=0.00, 0.10, 0.15), A contraction of the unit cell is observed on oxidation of the materials. The unit cell volume changes linearly with the mean oxidation state of the manganese. Rate constants for the process can consequently be determined from time resolved X-ray diffractograms, The reactions follow first-order kinetics. Arrhenius plots based on rate constants determined at 4 temperatures in the range 700-900 degrees C are linear as an indication that only one rate determining step is involved. The activation energy for oxidation is 136 kJ mol(-1) for LaMnO3.00, 179 kJ mol(-1) for La0.90Sr0.10Mn1.01 O-3.01, and 160 kJ mol(-1) for La0.84Sr0.15Mn1.01O3.00. (C) 1998 Academic Press. C1 Odense Univ, Dept Chem, DK-5230 Odense M, Denmark. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Andersen, EK (reprint author), Odense Univ, Dept Chem, Campusvej 55, DK-5230 Odense M, Denmark. RI Hanson, jonathan/E-3517-2010; Norby, Poul/B-9047-2014 OI Norby, Poul/0000-0002-2590-7050 NR 12 TC 16 Z9 16 U1 0 U2 8 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 NOV 15 PY 1998 VL 141 IS 1 BP 235 EP 240 PG 6 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA 146YU UT WOS:000077462100031 ER PT J AU Ghan, SJ Guzman, G Abdul-Razzak, H AF Ghan, SJ Guzman, G Abdul-Razzak, H TI Competition between sea salt and sulfate particles as cloud condensation nuclei SO JOURNAL OF THE ATMOSPHERIC SCIENCES LA English DT Article ID GENERAL-CIRCULATION MODEL; NORTHEAST ATLANTIC; AEROSOLS; SULFUR; SENSITIVITY; ALBEDO; OCEAN AB The influence of yea salt on the cloud droplet activation of sulfate particles is investigated using a size-resolving model of the aerosol activation process. The authors found that the total number concentration of activated cloud droplets increases with increasing sea salt concentration if the sulfate number concentrations are relatively low and updrafts are strong, but it decreases with higher sea salt if sulfate number concentrations are high and cloud updrafts are weak. The increase is due to the activation of accumulation mode sea salt particles. while the decrease is due to the reduction in maximum cloud supersaturation due to competition with coarse mode sea salt particles. These conclusions are insensitive to the sulfate size distribution and surface wind speed. C1 Pacific NW Lab, Richland, WA 99352 USA. Texas A&M Univ, Kingsville, TX USA. RP Ghan, SJ (reprint author), Pacific NW Lab, POB 999,Battelle Blvd, Richland, WA 99352 USA. EM steve.ghan@pnl.gov RI Ghan, Steven/H-4301-2011 OI Ghan, Steven/0000-0001-8355-8699 NR 24 TC 79 Z9 83 U1 0 U2 7 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 NOV 15 PY 1998 VL 55 IS 22 BP 3340 EP 3347 DI 10.1175/1520-0469(1998)055<3340:CBSSAS>2.0.CO;2 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 141YE UT WOS:000077171300002 ER PT J AU Choudry, MS Dollar, M Eastman, JA AF Choudry, MS Dollar, M Eastman, JA TI Nanocrystalline NiAl-processing, characterization and mechanical properties SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE nanocrystalline; microhardness; NiAl-processing ID NANOSTRUCTURED MATERIALS; DUCTILITY AB Nanocrystalline ordered NiAl (n-NiAl) was successfully synthesized by an electron beam gas condensation and compacted in-situ at various temperatures. As-compacted material exhibits grain sizes between 2 and 4 nm and densities between 78 and 94% of the theoretical density, increasing with increasing compaction temperature above all as a result of reduced porosity. The nanocrystalline structure of NiAl is stable up to about 1000 degrees C. Microhardness of as compacted n-NiAl increases with increasing density, above all as a result of reduced porosity. For the reasons not fully understood yet, microhardness of n-NiAl increases also with increasing grain size following annealing, a response different from that in the conventional, coarse-grained NiAl. The present material is significantly stronger than its conventional counterpart but not as strong as predicted by Hall-Fetch-type modeling. Also, in the nanocrystalline form, NiAl exhibits room temperature ductility, unlike its coarse-grained counterpart. The present study provides probably the first unequivocal experimental evidence of the room temperature ductility of a nanocrystalline intermetallic material. The mechanical behavior of n-NiAl can be rationalized assuming that diffusional, rather than dislocation, mechanisms control strength and ductility of n-materials. (C) 1998 Elsevier Science S.A. All rights reserved. C1 IIT, Mech Mat & Aerosp Engn Dept, Chicago, IL 60616 USA. Westinghouse Elect Corp, Power Generat Business Unit, Orlando, FL 32826 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. RP Dollar, M (reprint author), IIT, Mech Mat & Aerosp Engn Dept, Chicago, IL 60616 USA. RI Eastman, Jeffrey/E-4380-2011; OI Eastman, Jeff/0000-0002-0847-4265 NR 14 TC 26 Z9 26 U1 0 U2 4 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 NOV 15 PY 1998 VL 256 IS 1-2 BP 25 EP 33 DI 10.1016/S0921-5093(98)00810-7 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 142RF UT WOS:000077213600004 ER PT J AU Wang, JG Zhang, LC Chen, GL Ye, HQ AF Wang, JG Zhang, LC Chen, GL Ye, HQ TI TEM observations of mechanical twins in a hot-deformed Ti-45A1-10Nb alloy (vol 252, pg 222, 1998) SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Correction C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. Univ Sci & Technol Beijing, State Key Lab Adv Met & Mat, Beijing 100083, Peoples R China. Acad Sinica, Inst Met Res, Atom Imaging Solids Lab, Shenyang 110015, Peoples R China. RP Wang, JG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-370, Livermore, CA 94551 USA. NR 1 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD NOV 15 PY 1998 VL 256 IS 1-2 BP 315 EP 315 PG 1 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 142RF UT WOS:000077213600035 ER PT J AU Hoover, WG AF Hoover, WG TI Isomorphism linking smooth particles and embedded atoms SO PHYSICA A LA English DT Article DE surface tension; smooth particles; simulation ID APPLIED MECHANICS AB Macroscopic continuum simulations can be based on an unstructured moving spatial grid made up of "smooth particles". The smooth particles' equations of motion include interpolated values of the macroscopic stress gradient at each particle's position. Microscopic solid-state simulations can be based on the motion of "embedded atoms", with equations of motion based on a physical idea - embedding atoms in the local electronic density. The embedded atoms then move according to Newtonian equations of motion, based on electronic density gradients at each particle position. I show here that these two descriptions, macroscopic smooth particles and microscopic embedded atoms, can give identical particle trajectories. This demonstration facilitates the understanding of macroscopic models for surface tension and also suggests that certain macroscopic continuum approaches to smooth particle applied mechanics could have useful analogs in microscopic molecular dynamics. (C) 1998 Elsevier Science B.V. All rights reserved. PACS: 02.60; 05.20; 68.10.C; 68.10.M. C1 Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Hoover, WG (reprint author), Univ Calif Davis, Dept Appl Sci, Livermore, CA 94551 USA. NR 10 TC 25 Z9 28 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD NOV 15 PY 1998 VL 260 IS 3-4 BP 244 EP 254 DI 10.1016/S0378-4371(98)00357-4 PG 11 WC Physics, Multidisciplinary SC Physics GA 142JJ UT WOS:000077196900002 ER PT J AU Camassa, R Hyman, JM Luce, BP AF Camassa, R Hyman, JM Luce, BP TI Nonlinear waves and solitons in physical systems SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO ID SOLITARY WAVES; INVERSE SCATTERING; OPTICAL FIBERS; PERTURBATIONS; TRANSMISSION; DISPERSION AB Advances in nonlinear science have been plentiful in recent years. In particular, interest in nonlinear wave propagation continues to grow, stimulated by new applications, such as fiber-optic communication systems, as well as the many classical unresolved issues of fluid dynamics. What is arguably the turning point for the modern perspective of nonlinear systems took place at Los Alamos over 40 years ago with the pioneering numerical simulations of Fermi, Pasta, and Ulam. A decade later, this research initiated the next major advance of Zabusky and Kruskal that motivated the revolution in completely integrable systems. With this in mind, the conference on Nonlinear Waves in Solitons in Physical Systems (NWSPS) was organized by the Center for Nonlinear Studies (CNLS) at Los Alamos National Laboratory in May of 1997, to assess the current state-of-the-art in this very active field. Papers from the conference attendees as well as from researchers unable to attend the conference were collected in this special volume of Physica D. In this paper, the contributions to the conference and to this special issue are reviewed, with an emphasis on the many unifying principles that all these works share. Copyright (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Hyman, JM (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM jh@lanl.gov NR 84 TC 19 Z9 20 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 1 EP 20 DI 10.1016/S0167-2789(98)00108-0 PG 20 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600002 ER PT J AU Cai, D Gronbech-Jensen, N Bishop, AR Findikoglu, AT Reagor, D AF Cai, D Gronbech-Jensen, N Bishop, AR Findikoglu, AT Reagor, D TI A perturbed Toda lattice model for low loss nonlinear transmission lines SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO ID SRTIO3 AB In communications, radar, and digital electronics one traditionally uses discrete components that have unavoidable discontinuities at device or package interfaces. These components are typically used by designing a resonant response in the band of interest. Such resonant responses are inadequate for high data rates and, consequently, distributed devices are a topic of great current interest in high frequency electronics. The semiconductor based distributed devices recently developed have demonstrated fast responses. However, the limiting factor in these devices is the loss introduced by the semiconductor elements that introduces the nonlinearity. Future generations of high speed electronics will require distributed devices with lower loss but equivalent nonlinearity. Our earlier work on electrically tunable coplanar waveguide (CPW) devices incorporating nonlinear dielectric thin films of strontium barium titanate has shown that compact microwave devices based on nonlinear dielectric thin films are fast, broad-band, easily-tunable, and low loss (loss tangent < 10(-2)). These components are at lower loss than semiconductor components at the microwave frequencies of technological interest, enabling extensive use of nonlinear wave, self-focusing and pulse-shaping concepts when modeling the transmission lines. We are investigating the application of our novel materials technology and modeling to various distributed high speed signal processing problems in such low loss nonlinear transmission lines. We have modeled the transmission lines with discrete elements using a perturbed Toda lattice. Our full numerical simulations have shown that the transmission line is able to shape an input pulse into a train of stable traveling solitons. We have developed a perturbation theory to capture the soliton dynamics. We emphasize that how to couple a signal into the transmission line is an important issue in modeling soliton generation and transmission along the line in a realistic experimental setting. Copyright (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Cai, D (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, POB 1663, Los Alamos, NM 87545 USA. NR 7 TC 4 Z9 4 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 291 EP 300 DI 10.1016/S0167-2789(98)00128-6 PG 10 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600022 ER PT J AU Habib, S Khare, A Saxena, A AF Habib, S Khare, A Saxena, A TI Statistical mechanics of double sinh-Gordon kinks SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO DE double sinh-Gordon equation; quasi-exactly solvable (QES) potential; kink lattice; probability distribution function (PDF); Langevin dynamics ID STRUCTURAL PHASE-TRANSITIONS; IDEAL-GAS PHENOMENOLOGY; SCHRODINGER-EQUATION; 1+1 DIMENSIONS; MODEL; FIELDS; APPROXIMATION; POTENTIALS; BEHAVIOR; CRYSTALS AB We study the classical thermodynamics of the double sinh-Gordon (DSHG) theory in 1 + 1 dimensions. This model theory has a double well potential V (phi) = (zeta cosh 2 phi-n)(2) when n > zeta, thus allowing for the existence of kinks and antikinks. Though it is non-integrable, the DSHG model is remarkably amenable to analysis. Below we obtain exact single kink and kink lattice solutions as well as the asymptotic kink-antikink interaction. In the continuum limit, finding the classical partition function is equivalent to solving for the ground state of a Schrodinger-like equation obtained via the transfer integral method. For the DSHG model, this equation turns out to be quasi-exactly solvable. We exploit this property to obtain exact energy eigenvalues and wavefunctions for several temperatures both above and below the symmetry breaking transition temperature (provided n = 1, 2,..., 6). The availability of exact results provides an excellent testing ground for large scale Langevin simulations. The probability distribution function (PDF) calculated from Langevin dynamics is found to be in striking agreement with the exact PDF obtained from the ground state wavefunction. This validation points to the utility of a PDF-based computation of thermodynamics utilizing Langevin methods. In addition to the PDF, field-field and field fluctuation correlation functions were computed and also found to be in excellent agreement with the exact results. Copyright (C) 1998 Elsevier Science B.V, All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, T 8, Los Alamos, NM 87545 USA. Inst Phys, Bhubaneswar 751005, Orissa, India. Univ Calif Los Alamos Natl Lab, Div Theoret, T 11, Los Alamos, NM 87545 USA. RP Habib, S (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T 8, MS B285, Los Alamos, NM 87545 USA. EM habib@lanl.gov NR 47 TC 14 Z9 14 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 341 EP 356 DI 10.1016/S0167-2789(98)00133-X PG 16 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600027 ER PT J AU Sanati, M Saxena, A AF Sanati, M Saxena, A TI Domain walls in omega-phase transformations SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO DE Ginzburg-Landau model; asymmetric double-well potential; domain wall arrays and interaction; omega-phase transformation ID DIFFUSE-SCATTERING; ALLOYS; TRANSITIONS; EXAMPLE AB The beta-phase (body-centered cubic: b.c.c.) to omega-phase transformation in certain elements (e.g. Zr) and alloys (e.g. Zr-Nb) is induced either by quenching or application of pressure. The omega-phase is a metastable state and usually coexists with the beta-matrix in the form of small particles. To study the formation of domain walls in these materials we have extended the Landau model of Cook for the omega-phase transition by including a spatial gradient (Ginzburg) term of the scalar order parameter. In general, the Landau free energy is an asymmetric double-well potential. From the variational derivative of the total free energy we obtain a static equilibrium condition. By solving this equation for different physical parameters and boundary conditions, we obtained different quasi-one-dimensional soliton-like solutions. These solutions correspond to three different types of domain walls between the omega-phase and the beta-matrix. In addition, we obtained soliton lattice (domain wall array) solutions, calculated their formation energy and the asymptotic interaction between the solitons. Copyright (C) 1998 Published by Elsevier Science B.V. C1 Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Sanati, M (reprint author), Univ Cincinnati, Dept Phys, Cincinnati, OH 45221 USA. NR 26 TC 12 Z9 12 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 368 EP 379 DI 10.1016/S0167-2789(98)00135-3 PG 12 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600029 ER PT J AU Ben-Naim, E Knight, JB Nowak, ER Jaeger, HM Nagel, SR AF Ben-Naim, E Knight, JB Nowak, ER Jaeger, HM Nagel, SR TI Slow relaxation in granular compaction SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO DE granular materials; vibration; relaxation; hard spheres; adsorption ID SEQUENTIAL ADSORPTION; DYNAMICS; PACKING; LINE AB Experimental studies show that the density of a vibrated granular material evolves from a low density initial state into a higher density final steady state. The relaxation towards the final density follows an inverse logarithmic law. As the system approaches its final state, a growing number of beads have to be rearranged to enable a local density increase. A free volume argument shows that this number grows as N = rho/(1 - rho). The time scale associated with such events increases exponentially similar to e(N), and as a result a logarithmically slow approach to the final state is found rho(infinity) - rho(t) similar to 1/1nt. Furthermore, a one-dimensional toy model that captures this relaxation dynamics as well as the observed density fluctuations is discussed. Copyright (C) 1998 Published by Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Princeton Univ, Dept Phys, Princeton, NJ 08540 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Chicago, James Franck Inst, Chicago, IL 60637 USA. RP Ben-Naim, E (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RI Ben-Naim, Eli/C-7542-2009 OI Ben-Naim, Eli/0000-0002-2444-7304 NR 19 TC 91 Z9 91 U1 1 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 380 EP 385 DI 10.1016/S0167-2789(98)00136-5 PG 6 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600030 ER PT J AU Hagberg, A Meron, E AF Hagberg, A Meron, E TI Order parameter equations for front transitions: Nonuniformly curved fronts SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO DE spiral waves; reaction-diffusion; interface motion ID REACTION-DIFFUSION SYSTEM; EXCITABLE MEDIA; PATTERN-FORMATION; SPIRAL WAVES; PROPAGATION; BIFURCATIONS; DYNAMICS; EQUILIBRIUM; CURVATURE; VELOCITY AB Kinematic equations for the motion of slowly propagating, weakly curved fronts in bistable media are derived. The equations generalize earlier derivations where algebraic relations between the normal front velocity and its curvature are assumed. Such relations do not capture the dynamics near nonequilibrium Ising-Bloch (NIB) bifurcations, where transitions between counterpropagating Bloch fronts may spontaneously occur. The kinematic equations consist of coupled integro-diffential equations for the front curvature and the front velocity, the order parameter associated with the NIB bifurcation. They capture the NIB bifurcation, the instabilities of Ising and Bloch fronts to transverse perturbations, the core structure of a spiral wave, and the dynamic process of spiral wave nucleation. Copyright (C) 1998 Published by Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, T 7, Los Alamos, NM 87545 USA. Ben Gurion Univ Negev, Jacob Blaustein Inst Desert Res, IL-84990 Sede Boqer, Israel. Ben Gurion Univ Negev, Dept Phys, IL-84990 Sede Boqer, Israel. RP Hagberg, A (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RI MERON, EHUD/F-1810-2012 NR 48 TC 14 Z9 14 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 460 EP 473 DI 10.1016/S0167-2789(98)00143-2 PG 14 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600037 ER PT J AU Hyman, JM Rosenau, P AF Hyman, JM Rosenau, P TI Pulsating multiplet solutions of quintic wave equations SO PHYSICA D LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NEW MEXICO ID KORTEWEG-DEVRIES EQUATION; SOLITARY WAVES; KDV-TYPE; 5TH-ORDER; SOLITONS; EXISTENCE AB Numerical studies are used to demonstrate that, in addition to supporting conventional solitons, the quintic Korteweg-de Vries equation, u(t) + (u(2))x = u(xxxxx), and its regularized version, u(t) + (u(2))(x) + u(txxxx) = 0, support multihumped solitary waves (doublets, triplets, quadruplets, etc.), referred to collectively as multiplets. Their peaks pulsate as they travel and undergo nearly elastic collisions with other multiplets. An N-humped multiplet can pulsate thousands of cycles before disassociating into an (N - 1)-humped multiplet and a single-peak solitary wave (singlet). Although multiplets are easily created from an initial wide compact pulse, they rarely are formed by fusing singlets or multiplets in collisions. We describe the emergence and evolution of multiplets, their nearly elastic collision dynamics, and their eventual decomposition into singlets. To consider the effect of cubic dispersion on the solution of these equations, we also study mu(t) + (u(2)), + eta u(xxx) = delta u(xxxxx). The impact of cubic dispersion critically depends on the sign of eta and its amplitude. For sufficiently large eta > eta(1) > 0, only a train of singlets emerge from an initial pulse with compact support. If eta is decreased, multiplets begin to emerge leading the train of singlets. The number of humps in the multiplet increases as tl is decreased, until below a critical point eta < eta(infinity) < 0 the initial pulse decomposes into highly oscillatory waves. Copyright (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Tel Aviv Univ, Sch Math Sci, IL-69978 Tel Aviv, Israel. RP Hyman, JM (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 13 TC 11 Z9 11 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 502 EP 512 DI 10.1016/S0167-2789(98)00146-8 PG 11 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600040 ER PT J AU Vorobieff, P Ecke, RE AF Vorobieff, P Ecke, RE TI Vortex structure in rotating Rayleigh-Benard convection SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NM DE Rayleigh-Benard convection; vortex dynamics ID PARTICLE-IMAGE-VELOCIMETRY; NUMBER; FLUID; FLOW AB We investigate the flow patterns in a cylindrical rotating Rayleigh-Benard convection cell with radius-to-height ratio Gamma = 0.5. The Rayleigh number R is 2 x 10(8), the dimensionless rotation rate Omega varies from 9.6 x 10(3) to 4.8 x 10(4), and the convective Rossby number Ro is between 0.31 and 0.06. Measurements of the velocity field in the volume adjacent to the top of the cell are acquired with a scanning particle image velocimetry (PN) system. We present quantitative results for velocity and vorticity of the cyclonic and anticyclonic vortices characterizing the convection, as well as for the dependence of the vortex size on the rotation rate and variation of vorticity with depth. Copyright (C) 1998 Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies & Condensed Matter, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Thermal Phys Grp, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Ctr Nonlinear Studies & Condensed Matter, POB 1663, Los Alamos, NM 87545 USA. EM kalmoth@lanl.gov RI Vorobieff, Peter/B-3376-2011; OI Vorobieff, Peter/0000-0003-0631-7263; Ecke, Robert/0000-0001-7772-5876 NR 15 TC 23 Z9 23 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 EI 1872-8022 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 153 EP 160 DI 10.1016/S0167-2789(98)00118-3 PG 8 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600012 ER PT J AU Mitkov, I Zharnitsky, V AF Mitkov, I Zharnitsky, V TI pi-Kinks in the parametrically driven sine-Gordon equation and applications SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NM DE sine-Gordon equation; parametrical forcing; domain wall dynamics; easy-plane ferromagnets; normal form technique ID SOLITONS; FERROMAGNET; DYNAMICS; FIELD; CHAIN AB Parametrically driven sine-Gordon equation with a mean-zero forcing is considered. It is shown that the system is well approximated by the double sine-Gordon equation using the normal form technique. The reduced equation possesses pi-kink solutions, which are also observed numerically in the original system. This result is applied to domain walls dynamics in one-dimensional easy-plane ferromagnets. For such system the existence of pi-kinks implies the "true" domain structure in the presence of high-frequency magnetic field. Copyright (C) 1998 Elsevier Science B.V. C1 Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Computat Sci Methods Grp, Los Alamos, NM 87545 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Mitkov, I (reprint author), Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. EM igor@cnls.lanl.gov; vadim@cnls.lanl.gov NR 18 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 301 EP 307 DI 10.1016/S0167-2789(98)00129-8 PG 7 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600023 ER PT J AU Hammerberg, JE Holian, BL Roder, J Bishop, AR Zhou, SJ AF Hammerberg, JE Holian, BL Roder, J Bishop, AR Zhou, SJ TI Nonlinear dynamics and the problem of slip at material interfaces SO PHYSICA D-NONLINEAR PHENOMENA LA English DT Article; Proceedings Paper CT 17th Annual International Conference of the Center for Nonlinear Studies CY MAY 12-16, 1997 CL LOS ALAMOS, NM DE friction; molecular dynamics; dislocations; microstructure; Frenkel-Kontorova model ID FRICTION; DEFORMATION; MONOLAYERS AB The problem of dry friction between two metallic interfaces is discussed from the perspective of large scale molecular dynamics (MD) simulations. For flat interfaces between identical metals, two-dimensional MD simulations using embedded-atom-method potentials for copper have shown a variety of phenomena associated with a velocity weakening of the tangential force at high relative velocities (approaching significant fractions of the transverse sound speed). These include dislocation generation, dislocation motion both parallel and normal to the sliding interface, large plastic deformation, nucleation of microstructure, diffusive coarsening of microstructure, and material mixing. The early time behavior of a flat sliding interface is dominated by dislocation motion parallel to the interface. For this early stage, lower-dimensional models are useful in interpreting some of the simulation data. A two-chain forced Frenkel-Kontorova model reproduces some of the behavior of the larger scale simulations when the phenomenological damping is taken to be consistent with the MD simulations. This model exhibits four velocity regimes of steady state flow which will be discussed. Some of the implications for the nucleation of microstructure will be addressed. Copyright (C) 1998 Published by Elsevier Science B.V. C1 Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87544 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM USA. RP Hammerberg, JE (reprint author), Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87544 USA. EM jeh@lanl.gov NR 17 TC 97 Z9 98 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2789 J9 PHYSICA D JI Physica D PD NOV 15 PY 1998 VL 123 IS 1-4 BP 330 EP 340 DI 10.1016/S0167-2789(98)00132-8 PG 11 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA 152YW UT WOS:000077806600026 ER PT J AU Diener, J Shen, YR Kovalev, DI Polisski, G Koch, F AF Diener, J Shen, YR Kovalev, DI Polisski, G Koch, F TI Two-photon-excited photoluminescence from porous silicon SO PHYSICAL REVIEW B LA English DT Article ID NANOCRYSTALS; POLARIZATION; SPECTROSCOPY; ANISOTROPY; GENERATION; SI AB Two-photon-excited photoluminescence can be readily observed from porous silicon (PSi) with pulsed lasers. While its spectrum and lifetime are identical to those under one-photon excitation,;it has a degree of polarization significantly higher than the latter and depending on the orientation of the input polarization with respect to the crystalline axes of the sample. The degree of polarization is a maximum when the input polarization is along [110] in the surface plane of PSi prepared from a Si (100) wafer and a minimum along [010]. The results can be understood from selective excitation of ellipsoidal nanoparticles by linearly polarized light and intrinsic anisotropy in two-photon excitation of crystalline Si. [S0163-1829(98)05844-5]. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Tech Univ Munich, Phys Dept E16, D-85747 Garching, Germany. RP Diener, J (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. NR 21 TC 15 Z9 15 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 NOV 15 PY 1998 VL 58 IS 19 BP 12629 EP 12632 DI 10.1103/PhysRevB.58.12629 PG 4 WC Physics, Condensed Matter SC Physics GA 144CE UT WOS:000077295500026 ER PT J AU Pfrommer, BG Louie, SG AF Pfrommer, BG Louie, SG TI Density-functional study of the magnetic and metal-insulator transition of bcc hydrogen SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED-GRADIENT-APPROXIMATION; ELECTRONIC-STRUCTURE; MOTT INSULATORS; GROUND-STATE; EXCHANGE; OXIDES; EQUATION; SYSTEMS; GAP AB A model body-centered cubic (bcc) hydrogen solid is studied using density functional theory in the local spin density approximation (LSDA) and in the generalized gradient approximation (GGA). In GGA, the paramagnetic to antiferromagnetic phase transition occurs at a higher density, and is in much better agreement with previous variational quantum Monte Carlo (VQMC) calculations than LSDA. The metal-insulator transition in GGA is observed at a higher density and is also closer to the VQMC result than LSDA. In the limit of isolated hydrogen atoms, we find that in GGA the self-consistent electron density is greatly improved over LSDA due to a better cancellation of the electronic self-interaction. [S0163-1829(98)06343-7]. 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. NR 36 TC 8 Z9 8 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD NOV 15 PY 1998 VL 58 IS 19 BP 12680 EP 12683 DI 10.1103/PhysRevB.58.12680 PG 4 WC Physics, Condensed Matter SC Physics GA 144CE UT WOS:000077295500040 ER PT J AU Bao, W Broholm, C Aeppli, G Carter, SA Dai, P Rosenbaum, TF Honig, JM Metcalf, P Trevino, SF AF Bao, W Broholm, C Aeppli, G Carter, SA Dai, P Rosenbaum, TF Honig, JM Metcalf, P Trevino, SF TI Magnetic correlations and quantum criticality in the insulating antiferromagnetic, insulating spin liquid, renormalized Fermi liquid, and metallic antiferromagnetic phases of the Mott system V2O3 SO PHYSICAL REVIEW B LA English DT Review ID CR-DOPED V2O3; HUBBARD-MODEL; ITINERANT ANTIFERROMAGNETISM; ELECTRICAL-PROPERTIES; QUANTITATIVE ASPECTS; INFINITE DIMENSIONS; HIGH-PRESSURE; DENSITY-WAVE; NORMAL STATE; TRANSITION AB Magnetic correlations in all four phases of pure and doped vanadium sesquioxide (V2O3) have been examined by magnetic thermal-neutron scattering. Specifically, we have studied the antiferromagnetic and paramagnetic phases of metallic V2-yO3, the antiferromagnetic insulating and paramagnetic metallic phases of stoichiometric V2O3, and the antiferromagnetic and paramagnetic phases of insulating V1.944Cr0.056O3. While the antiferromagnetic insulator can be accounted for by a localized Heisenberg spin model, the long-range order in the antiferromagnetic metal is an incommensurate spin-density wave, resulting from a Fermi surface nesting instability. Spin dynamics in the strongly correlated metal are dominated by spin fluctuations with a "single lobe'' spectrum in the Stoner electron-hole continuum. Furthermore, our results in metallic V2O3 represent an unprecedentedly complete characterization of the spin fluctuations near a metallic quantum critical point, and provide quantitative support for the self-consistent renormalization theory for itinerant antiferromagnets in the small moment limit. Dynamic magnetic correlations for (h) over bar omega 800 keV) in the fission product gamma-ray spectrum. Ratios of the observed peak intensities are then formed. The values of these ratios can be compared to calculated theoretical values to identify the fissile material, The present work focuses on the differentiation between U-235 and Pu-239. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Colorado Sch Mines, Golden, CO 80401 USA. RP Beddingfield, DH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,NIS-5 MS E540, Los Alamos, NM 87545 USA. NR 2 TC 32 Z9 33 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD NOV 11 PY 1998 VL 417 IS 2-3 BP 405 EP 412 DI 10.1016/S0168-9002(98)00781-5 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA 138FG UT WOS:000076960200022 ER PT J AU Alivisatos, AP Barbara, PF Castleman, AW Chang, J Dixon, DA Klein, ML McLendon, GL Miller, JS Ratner, MA Rossky, PJ Stupp, SI Thompson, ME AF Alivisatos, AP Barbara, PF Castleman, AW Chang, J Dixon, DA Klein, ML McLendon, GL Miller, JS Ratner, MA Rossky, PJ Stupp, SI Thompson, ME TI From molecules to materials: Current trends and future directions SO ADVANCED MATERIALS LA English DT Article; Proceedings Paper CT Workshop on From Molecules to Materials CY APR 30-MAY 02, 1997 CL AUSTIN, TEXAS ID SCANNING OPTICAL MICROSCOPY; TRANSITION-METAL COMPLEXES; 3,4,9,10-PERYLENETETRACARBOXYLIC DIANHYDRIDE PTCDA; SPIN POLYNITROXIDE RADICALS; VERSATILE BRIDGING LIGANDS; ORGANIC SOLAR-CELLS; ROOM-TEMPERATURE; THIN-FILMS; GAS-PHASE; LASER VAPORIZATION AB The development, characterization, and exploitation of novel materials based on the assembly of molecular components is an exceptionally active and rapidly expanding field. For this reason, the topic of molecule-based materials (MBMs) was chosen as the subject of a workshop sponsored by the Chemical Sciences Division of the United States Department of Energy. The purpose of the workshop was to review and discuss the diverse research trajectories in the field from a chemical perspective, and to focus on the critical elements that are likely to be essential for rapid progress. The MBMs discussed encompass a diverse set of compositions and structures, including clusters, supramolecular assemblies, and assemblies incorporating biomolecule-based components. A full range of potentially interesting materials properties, including electronic, magnetic, optical, structural, mechanical, and chemical characteristics were considered. Key themes of the workshop included synthesis of novel components, structural control, characterization of structure and properties, and the development of underlying principles and models. MBMs, defined as "useful substances prepared from molecules or molecular ions that maintain aspects of the parent molecular framework" are of special significance because of the capacity for diversity in composition, structure, and properties, both chemical and physical. Key attributes are the ability in MBMs to access the additional dimension of multiple length scales and available structural complexity via organic chemistry synthetic methodologies and the innovative assembly of such diverse components. The interaction among the assembled components can thus lead to unique behavior. A consequence of the complexity is the need for a multiplicity of both existing and new tools for materials synthesis, assembly, characterization, and theoretical analysis. For some technologically useful properties, e.g., ferro- or ferrimagnetism and superconductivity, the property is not a property of a molecule or ion; it is a cooperative solid-state (bulk) property-a property of the entire solid. Hence, the desired properties are a consequence of the interactions between the molecules or ions, and understanding the solid-state structure as well as methods to predict, control, and modulate the structure are essential to understanding and manipulating such behaviors. As challenging as this is, molecules enable a substantially greater ability of control than atoms as building blocks for new materials and thus are well positioned to contribute significantly to new materials. The diversity of components and processes leads to the recognition of the critical role of cross-disciplinary research, including not only that between traditionally different areas within chemistry, but also between chemistry and biochemistry, physics, and a number of engineering disciplines. Enhancing communication and active collaboration between these groups was seen as a critical goal for the research area. C1 Univ Texas, Austin, TX 78712 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Minnesota, Minneapolis, MN 55455 USA. Penn State Univ, University Pk, PA 16802 USA. Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Univ Penn, Lab Res Struct Matter, Philadelphia, PA 19104 USA. Princeton Univ, Princeton, NJ 08544 USA. Univ Utah, Salt Lake City, UT 84112 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Illinois, Urbana, IL 61801 USA. Univ So Calif, Los Angeles, CA 90089 USA. RP Rossky, PJ (reprint author), Univ Texas, Austin, TX 78712 USA. RI Stupp, Samuel/B-6737-2009; Alivisatos , Paul /N-8863-2015; OI Alivisatos , Paul /0000-0001-6895-9048; Thompson, Mark/0000-0002-7764-4096 NR 216 TC 370 Z9 372 U1 14 U2 128 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD NOV 10 PY 1998 VL 10 IS 16 BP 1297 EP 1336 PG 40 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA 139UA UT WOS:000077047000002 ER PT J AU Erlandsen, H Flatmark, T Stevens, RC Hough, E AF Erlandsen, H Flatmark, T Stevens, RC Hough, E TI Crystallographic analysis of the human phenylalanine hydroxylase catalytic domain with bound catechol inhibitors at 2.0 angstrom resolution SO BIOCHEMISTRY LA English DT Article ID HUMAN TYROSINE-HYDROXYLASE; CRYSTAL-STRUCTURES; RESONANCE RAMAN; ACTIVE-SITE; IRON; 4-MONOOXYGENASE; PROTEIN; PHOSPHORYLATION; NORADRENALINE; MECHANISM AB The aromatic amino acid hydroxylases represent a superfamily of structurally and functionally closely related enzymes, one of those functions being reversible inhibition by catechol derivatives. Here we present the crystal structure of the dimeric catalytic domain (residues 117-424) of human phenylalanine hydroxylase (hPheOH), cocrystallized with various potent and well-known catechol inhibitors and refined at a resolution of 2.0 Angstrom. The catechols bind by bidentate coordination to each iron in both subunits of the dimer through the catechol hydroxyl groups, forming a blue-green colored ligand-to-metal charge-transfer complex. Ic. addition, Glu330 and Tyr325 are identified as determinant residues in the recognition of the inhibitors. In particular, the interaction with Glu330 conforms to the structural explanation for the pH dependence of catecholamine binding to PheOH, with a pK(a) value of 5.1 (20 degrees C). The overall structure of the catechol-bound enzyme is very similar to that of the uncomplexed enzyme (rms difference of 0.2 Angstrom for the C alpha atoms). Most striking is the replacement of two iron-bound water molecules with catechol hydroxyl groups. This change is consistent with a change in the ligand field symmetry of the high-spin (S = 5/2) Fe(III) from a rhombic to a nearly axial ligand field symmetry as seen upon noradrenaline binding using EPR spectroscopy [Martinez, A., Andersson, K. K., Haavik, J., and Flatmark, T. (1991) fur. J. Biochem. 198, 675-682]. Crystallographic comparison with the structurally related rat tyrosine hydroxylase binary complex with the oxidized cofactor 7,8-dihydrobiopterin revealed overlapping binding sites for the catechols and the cofactor, compatible with a competitive type of inhibition of the catechols versus BH4. The comparison demonstrates some structural differences at the active site as the potential basis for the different substrate specificity of the two enzymes. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Phys Biosci Div, Berkeley, CA 94720 USA. Univ Tromso, Dept Chem, Prot Crystallog Grp, N-9037 Tromso, Norway. Univ Bergen, Dept Biochem & Mol Biol, N-5009 Bergen, Norway. RP Stevens, RC (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 36 TC 46 Z9 47 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD NOV 10 PY 1998 VL 37 IS 45 BP 15638 EP 15646 DI 10.1021/bi9815290 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 141KT UT WOS:000077143600006 PM 9843368 ER PT J AU Field, EH Zeng, YH Johnson, PA Beresnev, IA AF Field, EH Zeng, YH Johnson, PA Beresnev, IA TI Nonlinear sediment response during the 1994 Northridge earthquake: Observations and finite source simulations SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID STRONG GROUND MOTION; LOMA-PRIETA EARTHQUAKE; SAN-FERNANDO EARTHQUAKE; SITE AMPLIFICATION; LOS-ANGELES; SOIL RESPONSE; S-WAVE; CALIFORNIA; PATH; AFTERSHOCKS AB We have addressed the long-standing question regarding nonlinear sediment response in the Los Angeles region by testing whether sediment amplification was similar between the Northridge earthquake and its aftershocks. Comparing the weak- and strong-motion site response at 15 sediment sites, we find that amplification factors were significantly less for the main shock implying systematic nonlinearity. The difference is largest between 2 and 4 Hz (4 factor of 2), and is significant at the 99% confidence level between 0.8 and 5.5 Hz. The inference of nonlinearity is robust with respect to the removal of possibly anomalous sediment sites and how the reference-site motion is defined. Furthermore, theoretical ground-motion simulations show no evidence of any bias from finite source effects during the main shock. Nonlinearity is also suggested by the fact that the four sediment sites that contain a clear fundamental resonance for the weak motion exhibit a conspicuous absence of the peak in the strong motion. Although we have taken the first step of establishing the presence of nonlinearity, it remains to define the physics of nonlinear response and to test the methodologies presently applied routinely in engineering practice. The inference of nonlinearity implies that care must be exercised in using sediment site data to study large earthquakes or predict strong ground motion. C1 Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. Univ Nevada, Seismol Lab, Reno, NV 89557 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Carleton Univ, Dept Earth Sci, Ottawa, ON K1S 5B6, Canada. RP Field, EH (reprint author), Univ So Calif, Dept Earth Sci, Los Angeles, CA 90089 USA. NR 65 TC 35 Z9 35 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 10 PY 1998 VL 103 IS B11 BP 26869 EP 26883 DI 10.1029/98JB02235 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 137MQ UT WOS:000076918900001 ER PT J AU Patton, HJ AF Patton, HJ TI Bias in the centroid moment tensor for central Asian earthquakes: Evidence from regional surface wave data SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID NUCLEAR-EXPLOSIONS; SOURCE PARAMETERS; DISCRIMINANT; PROPAGATION; CALIBRATION; EXCITATION; FAULT AB Surface waves recorded on the Chinese Digital Seismic Network (CDSN) station Urumqi (WMQ) are analyzed for 26 centroid moment tensor (CMT) earthquakes located within an epicentral distance of 1300 km. Applying a simple grid search method for source parameter retrieval, I obtain revised estimates of the focal depth, fault strike, and seismic moment (M-0) from amplitude spectra of Love and Rayleigh waves and compare these estimates with the CMT best double-couple solutions. The comparisons show that residuals are unbiased for focal depth and fault strike, where population spreads are +/-13 km and +/-17 degrees, respectively. On the other hand, M-0 estimates are found to be biased, with CMT M-0 larger than regional estimates by an average of 0.27 +/- 0.04 log units. The results for focal depth and strike are consistent with previous global and regional studies comparing independent estimates with CMT results. Recent full-waveform modeling studies for central Asian earthquakes support the findings of bias in M-0 estimates. I suggest that causes for M-0 bias may be related to great thicknesses of continental crust in Hindu Kush and Tien Shan regions and to data censoring practices at small magnitudes. M-0 : m(b) scaling relationships for central Asian earthquakes show better agreement with western U.S. scaling when M-0 estimates determined in this study are used. C1 Univ Calif Los Alamos Natl Lab, Geophys Grp, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Patton, HJ (reprint author), Univ Calif Los Alamos Natl Lab, Geophys Grp, Div Earth & Environm Sci, EES-3, Los Alamos, NM 87545 USA. NR 25 TC 17 Z9 20 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 10 PY 1998 VL 103 IS B11 BP 26963 EP 26974 DI 10.1029/98JB02529 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 137MQ UT WOS:000076918900006 ER PT J AU Reidel, SP AF Reidel, SP TI Emplacement of Columbia River flood basalt SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SADDLE MOUNTAINS; LAVA FLOWS; ERUPTION AB Evidence is examined for the emplacement of the Umatilla, Wilbur Creek, and the Asotin Members of Columbia River Basalt Group. These flows erupted in the eastern part of the Columbia Plateau during the waning phases of volcanism. The Umatilla Member consists of two flows in the Lewiston basin area and southwestern Columbia Plateau. These flows mixed to form one flow in the central Columbia Plateau. The composition of the younger flow is preserved in the center and the composition of the older flow is at the top and bottom. There is a complete gradation between the two. Flows of the Wilbur Creek and Asotin Members erupted individually in the eastern Columbia Plateau and also mixed together in the central Columbia Plateau. Comparison of the emplacement patterns to intraflow Structures and textures of the flows suggests that very little time elapsed between eruptions. In addition, the amount of crust that formed on the earlier flows prior to mixing also suggests rapid emplacement. Calculations of volumetric flow rates through constrictions in channels suggest emplacement times of weeks to months under fast laminar flow for all three members. A new model for the emplacement of Columbia River Basalt Group flows is proposed that suggests rapid eruption and emplacement for the main part of the flow and slower emplacement along the margins as the of the flow margin expands. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Reidel, SP (reprint author), Pacific NW Lab, POB 999,MS K6-81, Richland, WA 99352 USA. EM sp.reidel@pnl.gov NR 52 TC 38 Z9 38 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD NOV 10 PY 1998 VL 103 IS B11 BP 27393 EP 27410 DI 10.1029/97JB03671 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 137MQ UT WOS:000076918900034 ER PT J AU Burgess, JD Jones, VW Porter, MD Rhoten, MC Hawkridge, FM AF Burgess, JD Jones, VW Porter, MD Rhoten, MC Hawkridge, FM TI Scanning force microscopy images of cytochrome c oxidase immobilized in an electrode-supported lipid bilayer membrane SO LANGMUIR LA English DT Letter ID SELF-ASSEMBLED MONOLAYERS; VESICLE CRYSTALS; SURFACES; BEHAVIOR; BINDING; GOLD; AU; AG AB Scanning force microscopic images of cytochrome c oxidase immobilized within an electrode-supported lipid bilayer membrane are reported. These images represent the first direct evidence that the microscopic architecture of this important model system effectively mimics the microstructure proposed for the inner mitochondrial membrane. The images reveal (1) that the oxidase is present as monomers and small aggregates within the supported membrane and (2) that the oxidase constitutes similar to 20% of the lipid bilayer membrane. The latter finding allows an estimation of the lower limit for the minimum turnover rate (similar to 0.5 electrons/s) required for the transition of the oxidase from its resting to pulsed kinetic state. C1 US DOE, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Virginia Commonwealth Univ, Dept Chem, Richmond, VA 23284 USA. RP Porter, MD (reprint author), US DOE, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. EM mporter@porter1.ameslab.gov; fmhawkri@saturn.vcu.edu NR 28 TC 24 Z9 24 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD NOV 10 PY 1998 VL 14 IS 23 BP 6628 EP 6631 DI 10.1021/la980648d PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 138RY UT WOS:000076987600005 ER PT J AU Barenblatt, GI Bell, JB Crutchfield, WY AF Barenblatt, GI Bell, JB Crutchfield, WY TI The thermal explosion revisited SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article AB The classical problem of the thermal explosion in a long cylindrical vessel is modified so that only a fraction alpha of its wall is ideally thermally conducting while the remaining fraction l-alpha is thermally isolated. Partial isolation of the wall naturally reduces the critical radius of the vessel. Most interesting is the case when the structure of the boundary is a periodic one, so that the alternating conductive alpha and isolated 1-alpha parts of the boundary occupy together the segments 2 pi/N (N is the number of segments) of the boundary. A numerical investigation is performed. It is shown that at small alpha and large N, the critical radius obeys a scaling law with the coefficients depending on N. For large N, the result is obtained that in the central core of the vessel the temperature distribution is axisymmetric. In the boundary layer near the wall having the thickness approximate to 2 pi r(0)/N (r(0) is the radius of the vessel), the temperature distribution varies sharply in the peripheral direction. The temperature distribution in the axisymmetric core at the critical value of the vessel radius is subcritical. C1 Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Barenblatt, GI (reprint author), Univ Calif Berkeley, Dept Math, Berkeley, CA 94720 USA. NR 3 TC 10 Z9 10 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 10 PY 1998 VL 95 IS 23 BP 13384 EP 13386 DI 10.1073/pnas.95.23.13384 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 138WU UT WOS:000076997000007 PM 9811808 ER PT J AU Benzinger, TLS Gregory, DM Burkoth, TS Miller-Auer, H Lynn, DG Botto, RE Meredith, SC AF Benzinger, TLS Gregory, DM Burkoth, TS Miller-Auer, H Lynn, DG Botto, RE Meredith, SC TI Propagating structure of Alzheimer's beta-amyloid((10-35)) is parallel beta-sheet with residues in exact register SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SOLID-STATE NMR; DOUBLE-RESONANCE NMR; AMYLOID FIBRIL FORMATION; CROSS-LINKING; X-RAY; 5-ENOLPYRUVYLSHIKIMATE-3-PHOSPHATE SYNTHASE; EXCHANGE SPECTROSCOPY; DISTANCE MEASUREMENTS; ROTATIONAL RESONANCE; MOLECULAR-STRUCTURE AB The pathognomonic plaques of Alzheimer's disease are composed primarily of the 39- to 43-aa beta-amyloid (A beta) peptide. Crosslinking of A beta peptides by tissue transglutaminase (tTg) indicates that Gln(15) of one peptide is proximate to Lys(16) of another in aggregated A beta. sere se report how the fibril structure is resolved by mapping interstrand distances in this core region of the A beta peptide chain with solid-state NMR. Isotopic substitution provides the source points for measuring distances in aggregated A beta. Peptides containing a single carbonyl C-13 label at Gln15, Lys(16), Leu(17), Or Val(18) were synthesized and evaluated by NMR dipolar recoupling methods for the measurement of interpeptide distances to a resolution of 0.2 Angstrom. Analysis of these data establish that this central core of A beta consists of a parallel beta-sheet structure in which identical residues on adjacent chains are aligned directly, i,e., in register. Our data! in conjunction with existing structural data, establish that the A beta fibril is a hydrogen-bonded, parallel beta-sheet defining the long asis of the A beta fibril propagation. C1 Univ Chicago, Dept Chem, Chicago, IL 60637 USA. Univ Chicago, Dept Pathol, Chicago, IL 60637 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Lynn, DG (reprint author), Univ Chicago, Dept Chem, 5735 S Ellis Ave, Chicago, IL 60637 USA. EM d-lynn@uchicago.edu; robert-botto@qmgate.anl.gov; scmeredi@midway.uchicago.edu FU NCRR NIH HHS [R21 RR 12723]; NHLBI NIH HHS [5 T32 HL07327]; NICHD NIH HHS [T32 HD007327]; NIGMS NIH HHS [5 T32 GM07281, T32 GM007281] NR 82 TC 336 Z9 345 U1 4 U2 35 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 10 PY 1998 VL 95 IS 23 BP 13407 EP 13412 DI 10.1073/pnas.95.23.13407 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 138WU UT WOS:000076997000012 PM 9811813 ER PT J AU Hang, B Medina, M Fraenkel-Conrat, H Singer, B AF Hang, B Medina, M Fraenkel-Conrat, H Singer, B TI A 55-kDa protein isolated from human cells shows DNA glycosylase activity toward 3,N-4-ethenocytosine and the G/T mismatch SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID M13 VIRAL-DNA; ESCHERICHIA-COLI; OLIGODEOXYNUCLEOTIDE DUPLEX; LIPID-PEROXIDATION; OPPOSITE THYMIDINE; N-GLYCOSYLASE; ADDUCTS; SITE; 3,N-4-ETHENO-2'-DEOXYCYTIDINE; LESION AB Etheno adducts in DNA arise from multiple endogenous and exogenous sources. Of these adducts we have reported that, 1,N-6-ethenoadenine (epsilon A) and 3,N-4-ethenocytosine (epsilon C) are removed from DNA by two separate DNA glycosylases. We later confirmed these results by using a gene knockout mouse lacking alkylpurine-DNA-N-glycosylase, which excises epsilon A. The present work is directed toward identifying and purifying the human glycosylase activity releasing epsilon C. HeLa cells were subjected to multiple steps of column chromatography, including two epsilon C-DNA affinity columns, which resulted in >1,000-fold purification. Isolation and renaturation of the protein from SDS/polyacrylamide gel showed that the epsilon C activity resides in a 55-kDa polypeptide, This apparent molecular mass is approximately the same as reported for the human G/T mismatch thymine-DNA glycosylase, This latter activity copurified to the final column step and was present in the isolated protein band having epsilon C-DNA glycosylase activity, In addition, oligonucleotides containing epsilon C.G or G/T(U), could compete for epsilon C protein binding, further indicating that the epsilon C-DNA glycosylase is specific for both types of substrates in recognition. The same substrate specificity for epsilon C also was observed in a recombinant G/T mismatch DNA glycosylase from the thermophilic bacterium, Methanobacterium thermoautotrophicum THF. 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. FU NCI NIH HHS [R01 CA072079, CA 47723, CA 72079, R01 CA047723] NR 47 TC 74 Z9 74 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD NOV 10 PY 1998 VL 95 IS 23 BP 13561 EP 13566 DI 10.1073/pnas.95.23.13561 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 138WU UT WOS:000076997000038 PM 9811839 ER PT J AU Istrail, S Pevzner, P Shamir, R AF Istrail, S Pevzner, P Shamir, R TI Special volume - Computational Molecular Biology DAM-CMB series - Volume 2 - Foreword SO DISCRETE APPLIED MATHEMATICS LA English DT Editorial Material C1 Sandia Natl Labs, Algorithms & Discrete Math Dept, Albuquerque, NM 87185 USA. Univ So Calif, Dept Math, Los Angeles, CA 90089 USA. Tel Aviv Univ, Sch Math, Dept Comp Sci, IL-69978 Tel Aviv, Israel. RP Istrail, S (reprint author), Sandia Natl Labs, Algorithms & Discrete Math Dept, POB 5800,MS 1110, Albuquerque, NM 87185 USA. RI Shamir, Ron/E-6514-2011 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 0166-218X J9 DISCRETE APPL MATH JI Discret Appl. Math. PD NOV 9 PY 1998 VL 88 IS 1-3 BP 3 EP 6 DI 10.1016/S0166-218X(98)00109-7 PG 4 WC Mathematics, Applied SC Mathematics GA 144EF UT WOS:000077300400002 ER PT J AU Knill, E Bruno, WJ Torney, DC AF Knill, E Bruno, WJ Torney, DC TI Non-adaptive group testing in the presence of errors SO DISCRETE APPLIED MATHEMATICS LA English DT Article ID POOLING DESIGNS AB In group testing, the task is to determine the distinguished members of a set of objects O by asking subset queries of the form "does the set Q subset of or equal to O contain a distinguished object?" In biological applications of group testing, the task is to repeatedly screen a library of objects for those which are positive for a probe. The subset queries consist of screening a pooled subset of the objects with the probe. This procedure has become an important component of the experimental methods used for the compilation of physical maps of chromosomes and other genetic material. For many screening applications, it is most cost-effective to ask many subset queries in parallel. This leads to non-adaptive group testing problems. An important aspect of most screening environments is that the screening results are far from reliable. In this report we discuss some of the error models that can be used and show how they affect the design of non-adaptive screening experiments. We give a unified treatment of the known methods for constructing pooling designs, provide explicit formulas for their performance under different error assumptions and discuss the asymptotic performance of random designs. 1998 Published by Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Knill, E (reprint author), Univ Calif Los Alamos Natl Lab, MS B265, Los Alamos, NM 87545 USA. EM knill@c3serve.c3.lanl.gov NR 24 TC 17 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-218X J9 DISCRETE APPL MATH JI Discret Appl. Math. PD NOV 9 PY 1998 VL 88 IS 1-3 BP 261 EP 290 DI 10.1016/S0166-218X(98)00075-4 PG 30 WC Mathematics, Applied SC Mathematics GA 144EF UT WOS:000077300400014 ER PT J AU Dahl, DA Appelhans, AD AF Dahl, DA Appelhans, AD TI Sample charge compensation via self-charge-stabilizing ion optics SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY LA English DT Article DE ion optics; sample charging; secondary ion mass spectrometry; ion trap ID MASS-SPECTROMETRY; POLYMER SURFACES; SIMS AB A self-charge-stabilizing ion optics method to control electrostatic sample charging of insulators bombarded with energetic particles has been developed and evaluated. In this method, ion optical elements form a simple self-controlling electrostatic field servo loop that automatically Limits sample charging. The method has been applied successfully with insulating samples for secondary ion mass spectrometry in both quadrupole and ion trap based instruments. Self-charge-stabilizing ion optics appears to be a direct way to prevent or control sample charging in those circumstances where the approach is applicable. (Int J Mass Spectrom 178 (1998) 187-204) (C) 1998 Elsevier Science B.V. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Dahl, DA (reprint author), Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. NR 13 TC 19 Z9 19 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1387-3806 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. PD NOV 9 PY 1998 VL 178 IS 3 BP 187 EP 204 DI 10.1016/S1387-3806(98)14120-9 PG 18 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA 137FC UT WOS:000076903300005 ER PT J AU Wu, ZL Sheehan, L Kozlowski, MR AF Wu, ZL Sheehan, L Kozlowski, MR TI Laser modulated scattering as a nondestructive evaluation tool for defect inspection in optical materials for high power laser applications SO OPTICS EXPRESS LA English DT Article ID THIN-FILMS; PHOTOTHERMAL DEFLECTION; COATINGS; DAMAGE AB Laser modulated scattering (LMS) is introduced as a tool for defect inspection and characterization of optical materials for high power laser applications. LMS is a scatter sensitive version of the well-known photothermal microscopy techniques. Because only the defects of a superpolished optic generate a scattering signal, the technique is essentially a method for dark-field photothermal microscopy. Experimental results show that the technique (1) measures the local absorption properties of defects, contamination, and laser damage sites; (2) when used in conjunction with DC scattering, can differentiate between absorbing and non-absorbing defects; and (3) detects thermal transport inhomogeneities. (C)1998 Optical Society of America C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wu, ZL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 16 TC 11 Z9 12 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 1094-4087 J9 OPT EXPRESS JI Opt. Express PD NOV 9 PY 1998 VL 3 IS 10 BP 376 EP 383 PG 8 WC Optics SC Optics GA 137DW UT WOS:000076900400004 PM 19384384 ER PT J AU Chung, DJH Kolb, EW Riotto, A AF Chung, DJH Kolb, EW Riotto, A TI Nonthermal supermassive dark matter SO PHYSICAL REVIEW LETTERS LA English DT Article ID PARTICLE-PRODUCTION; BUBBLE COLLISIONS; INFLATION; UNIVERSE; DECAY AB We discuss several cosmological production mechanisms for nonthermal supermassive dark matter and argue that dark matter may be elementary particles of mass much greater than the weak scale. Searches for dark matter should not be limited to weakly interacting particles with mass of the order of the weak scale, but should extend into the supermassive range as well. [S0031-9007(98)07529-2]. C1 Univ Chicago, Dept Phys, Chicago, IL 60637 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Ctr, Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Dept Astron & Astrophys, Chicago, IL 60637 USA. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. RP Chung, DJH (reprint author), Univ Chicago, Dept Phys, Chicago, IL 60637 USA. EM djchung@theory.uchicago.edu; rocky@rigoletto.fnal.gov; riotto@nxth04.cern.ch NR 27 TC 153 Z9 154 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 NOV 9 PY 1998 VL 81 IS 19 BP 4048 EP 4051 DI 10.1103/PhysRevLett.81.4048 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000005 ER PT J AU Reyes, MA Berisso, MC Christian, DC Felix, J Gara, A Gottschalk, E Gutierrez, G Hartouni, EP Knapp, BC Kreisler, MN Lee, S Markianos, K Moreno, G Sosa, M Wang, MHLS Wehmann, A Wesson, D AF Reyes, MA Berisso, MC Christian, DC Felix, J Gara, A Gottschalk, E Gutierrez, G Hartouni, EP Knapp, BC Kreisler, MN Lee, S Markianos, K Moreno, G Sosa, M Wang, MHLS Wehmann, A Wesson, D TI Partial wave Analysis of the centrally produced KSKS system at 800 GeV/c SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCALAR GLUEBALL; F(0)(1500) AB Results are presented from a partial wave analysis of a sample of centrally produced mesons in the reaction pp --> p(slow)(KSKS)p(fast), with 800 GeV/c protons incident on a liquid hydrogen target. The meson system is found to be predominantly S wave in the mass range between KSKS threshold and 1.55 GeV/c(2). The f(0)(1500) is observed in this region. Above 1.55 GeV/c(2) two solutions are possible, one with mainly S wave and another with mainly D wave. This ambiguity prevents a unique determination of the spin of the f(J)(1710) meson. [S0031-9007(98)07609-1]. C1 Univ Guanajuato, Guanajuato, Mexico. Univ Massachusetts, Amherst, MA 01003 USA. Fermilab, Batavia, IL 60510 USA. Columbia Univ, Nevis Labs, Irvington, NY 10027 USA. RP Reyes, MA (reprint author), Univ Guanajuato, Guanajuato, Mexico. OI Hartouni, Edward/0000-0001-9869-4351 NR 13 TC 11 Z9 12 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 NOV 9 PY 1998 VL 81 IS 19 BP 4079 EP 4082 DI 10.1103/PhysRevLett.81.4079 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000013 ER PT J AU Mughabghab, SF Dunford, C AF Mughabghab, SF Dunford, C TI Nuclear level density and the effective nucleon mass SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORMULA; MODEL; PARAMETER AB Novel results were obtained for the spin dispersion parameter, which demonstrate the influence of the nucleon pairing correlations and shell effects in nuclei. The volume and Surface parameters of the level density parameter, as well as the shell-damping factor, were determined as a(upsilon) = 0.076 +/- 0.009 MeV-1 a(s) = 0.180 +/- 0.047 MeV-1, and gamma(0) = 0.47 +/- 0.04 MeV-1, respectively. The effective nucleon mass at the Fermi surface is found to be enhanced and its value is m*/m = 1.09 +/- 0.13. These findings are in excellent agreement with the theoretical estimates of Shlomo and Natowitz. [S0031-9007(98)07627-3]. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Mughabghab, SF (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 24 TC 45 Z9 45 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 9 PY 1998 VL 81 IS 19 BP 4083 EP 4086 DI 10.1103/PhysRevLett.81.4083 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000014 ER PT J AU Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Baldine, A Barabach, L Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Borocz, ZK Bucher, D Buijs, A Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Djordjadze, V Donni, P Doubovik, I Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Frolov, V Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Kim, H Kolb, BW Kosarev, I Koutcheryaev, I Krumpel, T Kugler, A Kulinich, P Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Maximov, A Mehdiyev, R Mgebrichvili, G Miake, Y Mikhalev, D Mishra, GC Miyamoto, Y Morrison, D Mukhopadhyay, DS Myalkovski, V Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nilsson, P Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Parfenov, A Pavliouk, S Pietzmann, T Patracek, V Pinanaud, W Plasil, F Purschke, ML Raeven, B Rak, J Raniwala, R Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Shabratova, G Sibiriak, I Siemiarczuk, T Silvermyr, D Sinha, BC Slavine, N Soderstrom, K Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Twenhofel, C Tykarski, L Urbahn, J von Eijndhoven, N von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Wyslouch, B Yagi, K Yokota, Y Young, GR AF Aggarwal, MM Agnihotri, A Ahammed, Z Angelis, ALS Antonenko, V Arefiev, V Astakhov, V Avdeitchikov, V Awes, TC Baba, PVKS Badyal, SK Baldine, A Barabach, L Barlag, C Bathe, S Batiounia, B Bernier, T Bhalla, KB Bhatia, VS Blume, C Bock, R Bohne, EM Borocz, ZK Bucher, D Buijs, A Busching, H Carlen, L Chalyshev, V Chattopadhyay, S Cherbatchev, R Chujo, T Claussen, A Das, AC Decowski, MP Djordjadze, V Donni, P Doubovik, I Majumdar, MRD El Chenawi, K Eliseev, S Enosawa, K Foka, P Fokin, S Frolov, V Ganti, MS Garpman, S Gavrishchuk, O Geurts, FJM Ghosh, TK Glasow, R Gupta, SK Guskov, B Gustafsson, HA Gutbrod, HH Higuchi, R Hrivnacova, I Ippolitov, M Kalechofsky, H Kamermans, R Kampert, KH Karadjev, K Karpio, K Kato, S Kees, S Kim, H Kolb, BW Kosarev, I Koutcheryaev, I Krumpel, T Kugler, A Kulinich, P Kurata, M Kurita, K Kuzmin, N Langbein, I Lebedev, A Lee, YY Lohner, H Luquin, L Mahapatra, DP Manko, V Martin, M Maximov, A Mehdiyev, R Mgebrichvili, G Miake, Y Mikhalev, D Mishra, GC Miyamoto, Y Morrison, D Mukhopadhyay, DS Myalkovski, V Naef, H Nandi, BK Nayak, SK Nayak, TK Neumaier, S Nianine, A Nikitine, V Nikolaev, S Nilsson, P Nishimura, S Nomokonov, P Nystrand, J Obenshain, FE Oskarsson, A Otterlund, I Pachr, M Parfenov, A Pavliouk, S Pietzmann, T Patracek, V Pinanaud, W Plasil, F Purschke, ML Raeven, B Rak, J Raniwala, R Raniwala, S Ramamurthy, VS Rao, NK Retiere, F Reygers, K Roland, G Rosselet, L Roufanov, I Roy, C Rubio, JM Sako, H Sambyal, SS Santo, R Sato, S Schlagheck, H Schmidt, HR Shabratova, G Sibiriak, I Siemiarczuk, T Silvermyr, D Sinha, BC Slavine, N Soderstrom, K Solomey, N Sorensen, SP Stankus, P Stefanek, G Steinberg, P Stenlund, E Stuken, D Sumbera, M Svensson, T Trivedi, MD Tsvetkov, A Twenhofel, C Tykarski, L Urbahn, J von Eijndhoven, N von Nieuwenhuizen, GJ Vinogradov, A Viyogi, YP Vodopianov, A Voros, S Wyslouch, B Yagi, K Yokota, Y Young, GR TI Centrality dependence of neutral pion production in 158A GeV Pb-208+Pb-208 collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSVERSE-MOMENTUM SPECTRA; MULTIPLICITY DEPENDENCE; HADRONIC COLLISIONS; NUCLEUS COLLISIONS; CHARGED-PARTICLES; P-NUCLEUS; DISTRIBUTIONS; ENERGIES; MODEL AB The production of neutral pions in 158A GeV Pb-208 + Pb-208 collisions has been studied in the WA98 experiment at the CERN Super Proton Synchrotron (SPS). Transverse momentum spectra are studied for the range 0.3 less than or equal to m(T) - m(0) less than or equal to 4.0 GeV/c. The results for central collisions are compared to various models. The centrality dependence of the neutral pion spectral shape and yield is investigated. An invariance of the spectral shape and a simple scaling of the yield with the number of participating nucleons is observed for centralities with greater than about 30 participating nucleons. This is most naturally explained by assuming an equilibrated system. [S0031-9007(98)07532-2]. C1 Panjab Univ, Chandigarh 160014, India. Univ Rajasthan, Jaipur 302004, Rajasthan, India. Bhabha Atom Res Ctr, Ctr Variable Energy Cyclotron, Calcutta 700064, W Bengal, India. Univ Geneva, CH-1211 Geneva 4, Switzerland. RRC Kurchatov, RU-123182 Moscow, Russia. Joint Nucl Res Inst, RU-141980 Dubna, Russia. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Jammu, Jammu 180001, India. Univ Munster, D-48149 Munster, Germany. Ecole Mines, SUBATECH, Nantes, France. Gesell Schwerionenforsch Inst Darmstadt, D-64220 Darmstadt, Germany. Univ Utrecht, NIKHEF, NL-3508 TA Utrecht, Netherlands. Univ Lund, SE-22100 Lund, Sweden. Univ Tsukuba, Tsukuba, Ibaraki 305, Japan. Nucl Res Inst, CZ-25068 Rez, Czech Republic. Univ Groningen, KVI, NL-9747 AA Groningen, Netherlands. Inst Nucl Studies, PL-00681 Warsaw, Poland. MIT, Cambridge, MA 02139 USA. Inst Phys, Bhubaneswar 751005, Orissa, India. Univ Tennessee, Knoxville, TN 37966 USA. RP Aggarwal, MM (reprint author), Panjab Univ, Chandigarh 160014, India. RI Decowski, Patrick/A-4341-2011; Mehdiyev, Rashid/H-6299-2013; Lohner, Herbert/B-2397-2014; Sumbera, Michal/O-7497-2014; OI Lohner, Herbert/0000-0002-7441-739X; Sumbera, Michal/0000-0002-0639-7323; Kampert, Karl-Heinz/0000-0002-2805-0195 NR 21 TC 67 Z9 68 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 NOV 9 PY 1998 VL 81 IS 19 BP 4087 EP 4091 DI 10.1103/PhysRevLett.81.4087 PG 5 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000015 ER PT J AU Steele, JV Koch, V AF Steele, JV Koch, V TI Lifetime of a disoriented chiral condensate SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-ENERGY COLLISIONS; DOMAINS; FORM AB The lifetime of a disoriented chiral condensate formed within a heat bath of pions is calculated assuming temperatures and densities attainable at present and future heavy-ion colliders. A generalization of the reduction formula to include coherent states allows us to derive a formula for the decay rate. We predict the half-life to be between 4 and 7 fm/c, depending on the assumed pion density. We also calculate the lifetime in the presence of higher resonances and baryons, which shortens the lifetime by at most 20%. [S0031-9007(98)07558-9]. C1 Ohio State Univ, Dept Phys, Columbus, OH 43210 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Steele, JV (reprint author), Ohio State Univ, Dept Phys, 174 W 18th Ave, Columbus, OH 43210 USA. NR 21 TC 12 Z9 12 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 NOV 9 PY 1998 VL 81 IS 19 BP 4096 EP 4099 DI 10.1103/PhysRevLett.81.4096 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000017 ER PT J AU Egolf, DA AF Egolf, DA TI Dynamical dimension of defects in spatiotemporal chaos SO PHYSICAL REVIEW LETTERS LA English DT Article ID GINZBURG-LANDAU EQUATION; MEDIATED TURBULENCE; PHASE TURBULENCE; TRANSITION; SYSTEMS; MODEL AB We utilize the dynamical fluctuations in spatiotemporal chaotic systems to elucidate the dynamical role of topological defects. We find that each defect in a representative defect-mediated system is associated with one to two degrees of dynamical freedom. Furthermore, we find that a significant fraction of the total degrees of freedom is not associated with the defects, and, in fact, appear to be related to the background phase turbulence. This new understanding of defect-mediated chaos provides hope that these complicated systems may be amenable to reduced statistical descriptions. [S0031-9007(98)07577-2]. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. RP Egolf, DA (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Ctr Nonlinear Studies, MS B258, Los Alamos, NM 87545 USA. NR 19 TC 15 Z9 15 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 NOV 9 PY 1998 VL 81 IS 19 BP 4120 EP 4123 DI 10.1103/PhysRevLett.81.4120 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000023 ER PT J AU Nellist, PD Pennycook, SJ AF Nellist, PD Pennycook, SJ TI Subangstrom resolution by underfocused incoherent transmission electron microscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID INFORMATION LIMIT AB It is quantitatively explained why incoherent transmission electron microscope imaging is extremely robust to the effects of chromatic aberration, which usually limits the resolution in the conventional coherent mode of imaging. Combining this robustness with using underfocus to counter the effects of spherical aberration, we demonstrate subangstrom lattice resolution and information transfer to 0.078 nm. C1 Univ Cambridge, Cavendish Lab, Cambridge CB3 0HE, England. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Nellist, PD (reprint author), Univ Birmingham, Sch Phys & Astron, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. NR 22 TC 112 Z9 112 U1 2 U2 27 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 9 PY 1998 VL 81 IS 19 BP 4156 EP 4159 DI 10.1103/PhysRevLett.81.4156 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000032 ER PT J AU Willemin, M Schilling, A Keller, H Rossel, C Hofer, J Welp, U Kwok, WK Olsson, RJ Crabtree, GW AF Willemin, M Schilling, A Keller, H Rossel, C Hofer, J Welp, U Kwok, WK Olsson, RJ Crabtree, GW TI First-order vortex-lattice melting transition in YBa2Cu3O7-delta near the critical temperature detected by magnetic torque SO PHYSICAL REVIEW LETTERS LA English DT Article ID UNTWINNED YBA2CU3O7-DELTA; HEAT EXPERIMENTS; LATENT-HEAT; LINE; SUPERCONDUCTORS; IRREVERSIBILITY; BI2SR2CACU2O8 AB High-resolution magnetic-torque studies on an untwinned YBa2Cu3O7-delta Single crystal near its critical temperature T-c reveal that the first-order vortex-lattice melting transition (VLMT) persists at least up to 0.5 K below T-c. The associated sharp discontinuity in magnetization is detectable even at temperatures where the torque signal deviates from mean-field behavior due to fluctuations. The magnetic irreversibility at the VLMT can be suppressed by applying a weak transverse ac magnetic field. This offers the possibility of separating the irreversibility line from the melting line near T-c. C1 Univ Zurich, Inst Phys, CH-8057 Zurich, Switzerland. IBM Corp, Div Res, Zurich Res Lab, CH-8803 Ruschlikon, Switzerland. Argonne Natl Lab, Sci & Technol Ctr Superconductiv, Argonne, IL 60439 USA. RP Willemin, M (reprint author), Univ Zurich, Inst Phys, Winterthurerstr 190, CH-8057 Zurich, Switzerland. NR 32 TC 69 Z9 69 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 NOV 9 PY 1998 VL 81 IS 19 BP 4236 EP 4239 DI 10.1103/PhysRevLett.81.4236 PG 4 WC Physics, Multidisciplinary SC Physics GA 139CW UT WOS:000077011000052 ER PT J AU Wright, AF Grossner, U AF Wright, AF Grossner, U TI The effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN SO APPLIED PHYSICS LETTERS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; DEFECTS; EFFICIENCY; METALS; FILMS AB Density-functional-theory calculations have been performed to study the effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN. Four candidate structures were examined and their formation energies were found to depend strongly on Fermi level and growth stoichiometry. A structure having gallium vacancies at the dislocation core is predicted to be most stable in n-type material grown under nitrogen-rich conditions, while a structure without vacancies is most stable in p-type material grown under these conditions. In material grown under gallium-rich conditions, a structure having nitrogen vacancies at the dislocation core is predicted to be most stable in p-type material, whereas a variety of core structures should be present in n-type material. Edge dislocations are predicted to behave as electron traps in n-type material and may act as hole traps in p-type material depending on the growth conditions. (C) 1998 American Institute of Physics. [S0003-6951(98)02545-5]. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Jena, Inst Festkorpertheorie & Theoret Opt, D-07743 Jena, Germany. RP Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. EM afwrigh@sandia.gov RI Grossner, Ulrike/A-5914-2008 NR 22 TC 171 Z9 172 U1 3 U2 34 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 NOV 8 PY 1998 VL 73 IS 19 BP 2751 EP 2753 DI 10.1063/1.122579 PG 3 WC Physics, Applied SC Physics GA 134HF UT WOS:000076736900017 ER PT J AU Brundermann, E Chamberlin, DR Haller, EE AF Brundermann, E Chamberlin, DR Haller, EE TI Thermal effects in widely tunable germanium terahertz lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID FAR-INFRARED-EMISSION; GE AB We report laser emission from Be-doped Ge lasers at high repetition rates of up to 45 kHz which is one order of magnitude higher than previously reported. Laser radiation was detected from Ge:Be crystals with volumes as small as 0.5 mm(3) and with intercontact distances down to 1 mm. We present a thermal analysis and derive the design parameters for continuous wave Ge lasers. [S0003-6951(98)00145-4]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Brundermann, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. RI Bruendermann, Erik/J-7186-2016 OI Bruendermann, Erik/0000-0003-4119-3489 NR 10 TC 19 Z9 19 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 NOV 8 PY 1998 VL 73 IS 19 BP 2757 EP 2759 PG 3 WC Physics, Applied SC Physics GA 134HF UT WOS:000076736900019 ER PT J AU Perlin, P Kisielowski, C Iota, V Weinstein, BA Mattos, L Shapiro, NA Kruger, J Weber, ER Yang, JW AF Perlin, P Kisielowski, C Iota, V Weinstein, BA Mattos, L Shapiro, NA Kruger, J Weber, ER Yang, JW TI InGaN/GaN quantum wells studied by high pressure, variable temperature, and excitation power spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID LIGHT-EMITTING-DIODES; III-V NITRIDES; ELASTIC-CONSTANTS; SINGLE; GA1-XINXN; EMISSION; FILMS; GAN AB The energies of photo- and electroluminescence transitions in InxGa1-xN quantum wells exhibit a characteristic "blueshift'' with increasing pumping power. This effect has been attributed either to band-tail filling, or to screening of piezoelectric fields. We have studied the pressure and temperature behavior of radiative recombination in InxGa1-xN/GaN quantum wells with x = 0.06, 0.10, and 0.15. We find that, although the recombination has primarily a band-to-band character, the excitation-power induced blueshift can be attributed uniquely to piezoelectric screening. Calculations of the piezoelectric field in pseudomorphic InxGa1-xN layers agree very well with the observed Stokes redshift of the photoluminescence. The observed pressure coefficients of the photoluminescence (25-37 meV/GPa) are surprisingly low, and, so far, their magnitude can only be partially explained. (C) 1998 American Institute of Physics. [S0003-6951(98)01045-6]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. SUNY Buffalo, Dept Phys, Buffalo, NY 14260 USA. APA Opt, Blaine, MN 55449 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM pperlin@ux8.lbl.gov NR 27 TC 93 Z9 94 U1 0 U2 8 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 NOV 8 PY 1998 VL 73 IS 19 BP 2778 EP 2780 DI 10.1063/1.122588 PG 3 WC Physics, Applied SC Physics GA 134HF UT WOS:000076736900026 ER PT J AU Curtiss, LA Raghavachari, K Redfern, PC Rassolov, V Pople, JA AF Curtiss, LA Raghavachari, K Redfern, PC Rassolov, V Pople, JA TI Gaussian-3 (G3) theory for molecules containing first and second-row atoms SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SET MODEL CHEMISTRY; QUADRATIC CONFIGURATION-INTERACTION; 2ND-ROW COMPOUNDS; CORE CORRELATION; ORBITAL METHODS; WAVE-FUNCTIONS; ENERGIES; 1ST-ROW AB Gaussian-3 theory (G3 theory) for the calculation of molecular energies of compounds containing first (Li-F) and second row (Na-Cl) atoms is presented. This new theoretical procedure, which is based on ab initio molecular-orbital theory, modifies G2 theory [J. Chem. Phys. 94, 7221 (1991)] in several ways including a new sequence of single point energy calculations using different basis sets, a new formulation of the higher level correction, a spin-orbit correction for atoms, and a correction for core correlation. G3 theory is assessed using 299 energies from the G2/97 test set including enthalpies of formation, ionization potentials, electron affinities, and proton affinities. This new procedure corrects many of the deficiencies of G2 theory. There is a large improvement for nonhydrogen systems such as SiF(4) and CF(4), substituted hydrocarbons, and unsaturated cyclic species. Core-related correlation is found to be a significant factor, especially for species with unsaturated rings. The average absolute deviation from experiment for the 148 calculated enthalpies of formation is reduced to under one kcal/mol, from 1.56 kcal/mol for G2 theory to 0.94 kcal/mol for G3 theory. Significant improvement is also found for ionization potentials and electron affinities. The overall average absolute deviation of G3 theory from experiment for the 299 energies is 1.02 kcal/mol compared to 1.48 kcal/mol for G2 theory. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. EM curtiss@anlchm.chm.anl.gov OI Rassolov, Vitaly/0000-0002-7244-8870 NR 39 TC 2232 Z9 2254 U1 7 U2 107 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 8 PY 1998 VL 109 IS 18 BP 7764 EP 7776 DI 10.1063/1.477422 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 132ZZ UT WOS:000076663100012 ER PT J AU Green, PF Brow, RK Hudgens, JJ AF Green, PF Brow, RK Hudgens, JJ TI Specific heat and transport "anomalies" in mixed alkali glasses SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SILICATE-GLASSES; VIBRATIONAL SPECTROSCOPY; LIQUIDS; TRANSITION; PHOSPHATE; NMR; RESONANCE; FRAGILITY; EXAFS AB We show that changes in the relative mole fractions of Li2O and Na2O in alkali metaphosphate glasses lead to "anomalies" in the specific heat and structural relaxations. The heat capacity change between the liquid and glassy states, Delta c(p)(T-g), at the calorimetric glass transition temperature, T-g, exhibits a minimum when the mole fractions of Li2O and Na2O are comparable. Moreover, systematic changes in the temperature dependence of the viscosity, eta, i.e., changes in the "fragility" of the system, accompany these changes in mole fraction. This observed dependence of the ''fragility'' on the mixed alkali ion composition occurs in the absence of apparent changes in the covalent network connectivity which normally accounts for this behavior in glasses. (C) 1998 American Institute of Physics. [S0021-9606(98)51342-6]. C1 Univ Texas, Texas Mat Inst, Dept Chem Engn, Austin, TX 78712 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Green, PF (reprint author), Univ Texas, Texas Mat Inst, Dept Chem Engn, Austin, TX 78712 USA. NR 43 TC 8 Z9 8 U1 3 U2 5 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD NOV 8 PY 1998 VL 109 IS 18 BP 7907 EP 7912 DI 10.1063/1.477438 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 132ZZ UT WOS:000076663100028 ER PT J AU Rao, RM Beuhler, RJ White, MG AF Rao, RM Beuhler, RJ White, MG TI Nonthermal photodesorption of N-2 from Ag(111) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LASER-INDUCED DESORPTION; INDUCED THERMAL-DESORPTION; FEMTOSECOND SURFACE-CHEMISTRY; SINGLE-PHONON DESORPTION; IMAGE-POTENTIAL STATES; CO; MECHANISM; ELECTRONS; CU(100); ENERGY AB We have measured translational and rotational energy distributions of N-2 molecules following desorption from a Ag(111) surface by infrared (1064 nm) radiation. The observed desorption yields were large even at laser fluences far below that required for laser-induced thermal desorption. State-resolved laser techniques using coherent VUV radiation showed that the rotational and translational energy distributions of the desorbing N-2 molecules are not consistent with the predictions of the heat diffusion model governing laser-induced surface heating. These results suggest that physisorbed adsorbates can couple directly to the nascent-phonon distribution or the nascent electron-hole pairs in the photoexcited substrate without heating of the surface. (C) 1998 American Institute of Physics. [S0021-9606(98)70542-2] C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rao, RM (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. NR 59 TC 7 Z9 7 U1 0 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 NOV 8 PY 1998 VL 109 IS 18 BP 8016 EP 8026 DI 10.1063/1.477449 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 132ZZ UT WOS:000076663100040 ER PT J AU Okada, M Poker, DB Zehner, DM AF Okada, M Poker, DB Zehner, DM TI Absolute deuterium coverage determination for the Mo0.75Re0.25(100), (110), and (111) surfaces SO SURFACE SCIENCE LA English DT Article DE deuterium; hydrogen; low-energy electron diffraction (LEED); low-index single-crystal surfaces; molybdenum; nuclear reaction analysis; rhenium; thermal desorption spectroscopy ID ALKALI-ION-SCATTERING; HYDROGEN ADSORPTION; W(110) SURFACE; PHASE-TRANSITIONS; MO(110) SURFACE; MO(001) SURFACE; W(001) SURFACE; RECONSTRUCTION; CHEMISORPTION; H/MO(100) AB Adsorption of hydrogen (deuterium) on the (100), (110), and (111) surfaces of the random alloy Mo0.75Re0.25 has been studied with low-energy electron diffraction (LEED), temperature-programmed desorption, and nuclear reaction analysis. The relative distribution of Mo and Re in the outermost layers of these surfaces is orientation-dependent. Following exposure to D-2, only (1 x 1) patterns are observed with LEED for all surfaces and D coverages, indicating no adsorbate-induced reconstruction. Using the D (He-3, p)He-4 reaction, the saturation coverages for the (100), (110), and (111) surfaces are determined to be 2.02 +/- 0.10, 0.99 +/- 0.05, and 2.86 +/- 0.24 ML, respectively. No bulk absorption of D is observed after exposure to either D-2 or D for all three surfaces. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. RP Zehner, DM (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 49 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 8 PY 1998 VL 417 IS 1 BP 1 EP 8 DI 10.1016/S0039-6028(98)00570-6 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 140QY UT WOS:000077100900005 ER PT J AU Liu, P Kendelewicz, T Brown, GE Nelson, EJ Chambers, SA AF Liu, P Kendelewicz, T Brown, GE Nelson, EJ Chambers, SA TI Reaction of water vapor with alpha-Al2O3(0001) and alpha-Fe2O3(0001) surfaces: synchrotron X-ray photoemission studies and thermodynamic calculations SO SURFACE SCIENCE LA English DT Article DE aluminum oxide; iron oxide; single-crystal surfaces; surface defects; synchrotron radiation photoelectron spectroscopy; water ID ENERGY-ELECTRON DIFFRACTION; IRON-OXIDE SURFACES; ALPHA-ALUMINA; PHOTOELECTRON-SPECTROSCOPY; XPS; RELAXATION; ADSORPTION; MORPHOLOGY; GROWTH; MG AB X-ray photoemission experiments were carried out to study the reaction of water vapor with clean (0001) surfaces of single-crystal corundum (alpha-Al2O3) and single-crystal, thin-film hematite (alpha-Fe2O3) at constant reaction time (3 min) as a function of water vapor pressure [p(H2O)] and, in separate experiments, at longer reaction times (=30 min, with total exposure ranging from 1.8 L to 1.8 x 10(10) L) at constant p(H2O). A two-stage reaction was observed for each oxide surface, with dissociative chemisorption of water occurring mainly at defect sites below threshold pressures of approximate to 1 Torr and approximate to 10(-4) Torr for the corundum and hematite (0001) surfaces, respectively. Extensive hydroxylation of these surfaces was found to occur above the respective threshold pressures. Longer exposures to water vapor below these threshold pressures did not result in increased hydroxylation; however, longer exposures above these threshold pressures resulted in increased hydroxylation, as expected. The threshold pressure of alpha-Al2O3 was accurately predicted using a simple equilibrium thermodynamic model for the conversion of corundum to gibbsite (AI(OH)(3)). In contrast, the measured threshold pressure for hematite is more than five orders of magnitude lower than the predicted threshold pressure for the conversion of hematite to FeOOH or Fe(OH)(3). This difference between observation and prediction for hematite (0001) is not completely understood, but may be due to the presence of a passivating layer of Fe-hydroxide that reduces the surface energy of the hydroxylated hematite (0001). (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Stanford Univ, Dept Geog & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. Stanford Linear Accelerator Ctr, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Liu, P (reprint author), Stanford Univ, Dept Geog & Environm Sci, Surface & Aqueous Geochem Grp, Stanford, CA 94305 USA. EM pingl@pangea.stanford.edu NR 67 TC 193 Z9 193 U1 12 U2 84 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 8 PY 1998 VL 417 IS 1 BP 53 EP 65 DI 10.1016/S0039-6028(98)00661-X PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 140QY UT WOS:000077100900010 ER PT J AU Henderson, MA Joyce, SA Rustad, JR AF Henderson, MA Joyce, SA Rustad, JR TI Interaction of water with the (1x1) and (2x1) surfaces of alpha-Fe2O3(012) SO SURFACE SCIENCE LA English DT Article DE auger electron spectroscopy (AES); electron energy loss spectroscopy (EELS); iron oxide; low energy electron diffraction (LEED); secondary ion mass spectroscopy; single crystal surfaces; surface chemical reaction; thermal desorption spectroscopy; vibrations of adsorbed molecules; water ID HYDROGEN DESORPTION; ELECTRONIC-STRUCTURE; MONOHYDRIDE PHASE; OXIDE SURFACES; ADSORPTION; MECHANISM; HEMATITE; SPECTROSCOPY; TRANSITION; TIO2(110) AB The interaction of water with the (1x1) and (2x1) surfaces of alpha-Fe2O3(012) was examined with temperature programmed desorption (TPD), static secondary ion mass spectrometry (SSIMS), low energy electron diffraction (LEED) and high resolution electron energy loss spectroscopy (HREELS) in the temperature range between 100 and 950 K. The (1x1) surface is fully oxidized and has a bulk-like concentration and structure of cation and anion sites. After vacuum annealing at 950 K a (2 x 1) pattern is observed in LEED. Although the structure of the (2 x 1) surface is not fully understood, it possesses a greater surface concentration of cation sites than the (1 x 1) surface, some of which are probably reduced. H2O adsorbs dissociatively on both surfaces as evidenced by KREELS losses at 3625 and 960 cm(-1) due to the stretching and bending modes of terminal hydroxyl groups. These losses shift as expected for D2O. Bridging hydroxyls are also formed by proton transfer to bridging oxygen anion sites from dissociating water molecules, but have a poorly resolved O-H stretch at 3400 cm(-1) suggesting they are involved in hydrogen-bonding interactions. Further evidence for water dissociation on both surfaces comes from isotopic scrambling of oxygen between these hydroxyls and the O-18-enriched surfaces. Although both surfaces dissociate water, the structural differences between the (1 x 1) and (2x1) surfaces result in different ratios of molecular-to-dissociative water. Terminal hydroxyls occupy roughly 6x10(14) sites cm(-2) on the (1 x 1) surface, but only about 4.5 x 10(14) sites cm(-2) on the (2 x 1) surface. The balance of available cation sites bind molecular water that evolves in TPD below 300 K from either surface. This molecular water is readily detected in both HREELS and SSIMS. The surface structure also influences the hydroxyl recombinative desorption kinetics. Terminal and bridging hydroxyls recombine to liberate water in TPD at 350 K from the (1 x 1) surface and at 405 K from the (2 x 1) surface. The recombinative desorption state of water at 350 K from the (1 x 1) surface exhibits first-order desorption kinetics with an activation energy of about 120 kJ mol(-1) and a pre-exponential of 1 x 10(17) s(-1). The first-order behavior and the high pre-exponential suggests that recombinative desorption from the (1 x 1 ) surface involves pairing of bridging and terminal hydroxyl groups. In contrast, recombinative desorption from the (2 x 1) surface is pseudo-zeroth order in appearance suggesting that hydroxyls are bound in one-dimensional arrays with desorption occurring preferentially at the ends of each array. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Henderson, MA (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K8-93, Richland, WA 99352 USA. RI Joyce, Stephen/Q-7804-2016 OI Joyce, Stephen/0000-0003-1330-7362 NR 32 TC 90 Z9 90 U1 2 U2 40 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD NOV 8 PY 1998 VL 417 IS 1 BP 66 EP 81 DI 10.1016/S0039-6028(98)00662-1 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA 140QY UT WOS:000077100900011 ER PT J AU Cameron, TM Baker, RT Westcott, SA AF Cameron, TM Baker, RT Westcott, SA TI Metal-catalysed multiple boration of ketimines SO CHEMICAL COMMUNICATIONS LA English DT Article ID BETA-AMINO ALCOHOLS; COUPLING REACTION; B BONDS; DIBORATION; HYDROBORATION; ALKENES; VINYLARENES; MECHANISM; COMPLEXES; ALKYNES AB Metal-catalysed addition of B(2)cat(2)' (cat' = 4-Bu-t-1,2-O2C6H3) to ketimines affords N-borylenamines and HBcat'. Analogous catalysed reactions of ketimines with HBcat' in tetrahydrofuran afford multiply berated products, providing the first examples of metal-catalysed hydroboration of enamines. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Mt Allison Univ, Dept Chem, Sackville, NB E4L 1G8, Canada. RP Baker, RT (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, MS 1514, Los Alamos, NM 87545 USA. NR 31 TC 21 Z9 21 U1 0 U2 3 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD NOV 7 PY 1998 IS 21 BP 2395 EP 2396 DI 10.1039/a805792c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA 136FQ UT WOS:000076848200056 ER PT J AU Rodriguez, JA Chaturvedi, S Jirsak, T AF Rodriguez, JA Chaturvedi, S Jirsak, T TI The bonding of sulfur to Pd surfaces: photoemission and molecular-orbital studies SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PD(111) SURFACE; MOSX FILMS; CATALYSTS; HYDROGEN; S-2; NI; CHEMISORPTION; ADSORPTION; S/MO(110); SULFIDE AB The adsorption and dissociation of S-2 on Pd(111) and polycrystalline Pd were studied using synchrotron-based high-resolution photoemission spectroscopy and ab initio SCF calculations. The photoemission results show several sulfur species with distinct electronic properties. The formation of Pd-S bonds induces large positive binding-energy shifts in the core and valence levels of Pd. After chemisorbing sulfur on the Pd surfaces, there is a substantial decrease in the electron density that the metal exhibits near the Fermi level and a simultaneous drop in the electron population of its 4d band. Pd is more sensitive to sulfur than other metals frequently used in automotive exhaust catalysts (Rh and Pt). (C) 1998 Elsevier Science B.V. All rights reserved. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov NR 35 TC 39 Z9 41 U1 0 U2 8 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 NOV 6 PY 1998 VL 296 IS 3-4 BP 421 EP 428 DI 10.1016/S0009-2614(98)01011-2 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 135PF UT WOS:000076811000033 ER PT J AU Norton, DP Park, C Prouteau, C Christen, DK Chisholm, MF Budai, JD Pennycook, SJ Goyal, A Sun, EY Lee, DF Kroeger, DM Specht, E Paranthaman, M Browning, ND AF Norton, DP Park, C Prouteau, C Christen, DK Chisholm, MF Budai, JD Pennycook, SJ Goyal, A Sun, EY Lee, DF Kroeger, DM Specht, E Paranthaman, M Browning, ND TI Epitaxial YBa2Cu3O7 films on rolled-textured metals for high-temperature superconducting applications SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 4th International Workshop on Oxide Electronics CY DEC 08-09, 1997 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP DARPA, Univ Maryland, NSF-MRSEC, Univ Maryland, Ctr Superconduct Res HO UNIV MARYLAND DE rolled-textured metals; high-temperature superconducting; epitaxial growth ID CRITICAL-CURRENT DENSITY; THIN-FILMS; TAPES; DEPOSITION; GROWTH; NICKEL; OXIDE AB The epitaxial growth of high temperature superconducting (HTS) films on rolled-textured metal represents a viable approach for long-length superconducting tapes. Epitaxial, 0.5 mu m thick YBa2Cu3O7 (YBCO) films with critical current densities, J(c), greater than 1 MA cm(-2) have been realized on rolled-textured (001) Ni tapes with yttria-stabilized zirconia (YSZ)/CeO2 oxide buffer layers. This paper describes the synthesis using pulsed-laser deposition (PLD) of epitaxial oxide buffer layers on biaxially-textured metal that comprise the so-called rolling-assisted biaxially-textured substrates (RABiTS(TM)). The properties of the buffer and YBa2Cu3O7 films on rolled-textured Ni are discussed, with emphasis given to the crystallographic and microstructural properties that determine the superconducting properties of these multilayer structures. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Illinois, Dept Phys, Chicago, IL 60607 USA. RP Norton, DP (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. RI Yoon, Sejin/F-7637-2013; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016; Specht, Eliot/A-5654-2009; OI Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306; Specht, Eliot/0000-0002-3191-2163; Browning, Nigel/0000-0003-0491-251X NR 21 TC 37 Z9 38 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD NOV 6 PY 1998 VL 56 IS 2-3 BP 86 EP 94 PG 9 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 150GK UT WOS:000077655700003 ER PT J AU Jia, QX Fan, Y Mombourquette, C Reagor, D AF Jia, QX Fan, Y Mombourquette, C Reagor, D TI Development of ramp-edge SNS Josephson junctions and SQUIDs SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 4th International Workshop on Oxide Electronics CY DEC 08-09, 1997 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP DARPA, Univ Maryland, NSF-MRSEC, Univ Maryland, Ctr Superconduct Res HO UNIV MARYLAND DE Josephson junctions; SQUIDs; thin films; superconductors ID DC SQUIDS; LOW-NOISE; THIN-FILMS; BARRIERS; MAGNETOMETERS; RESISTANCE AB We have fabricated high performance Josephson junctions, de SQUIDs, and directly-coupled SQUID magnetometers, where the junction uses a ramp-edge superconductor/normal-metal/superconductor (SNS) configuration. The devices are fully defined by the standard photolithography. We use Ag-doped YBa2Cu3O7-x for the superconducting electrodes and PrBa2Cu3O7-x as the N-layer barrier. The controllability of the processing and the reproducibility of the device performance was improved substantially by using Ag-doped YBa2Cu3O7-x for the electrodes. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Jia, QX (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Mail Stop K763, Los Alamos, NM 87545 USA. EM qxjia@lanl.gov RI Jia, Q. X./C-5194-2008 NR 27 TC 0 Z9 0 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD NOV 6 PY 1998 VL 56 IS 2-3 BP 95 EP 99 DI 10.1016/S0921-5107(98)00224-4 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 150GK UT WOS:000077655700004 ER PT J AU Theis, CD Yeh, J Schlom, DG Hawley, ME Brown, GW AF Theis, CD Yeh, J Schlom, DG Hawley, ME Brown, GW TI The influence of vicinal SrTiO3 surfaces on the growth and ferroelectric properties of epitaxial Bi4Ti3O12 thin films SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 4th International Workshop on Oxide Electronics CY DEC 08-09, 1997 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP DARPA, Univ Maryland, NSF-MRSEC, Univ Maryland, Ctr Superconduct Res HO UNIV MARYLAND DE Bi4Ti3O12; epitaxy; vicinal; oxide MBE; ferroelectric ID MOLECULAR-BEAM EPITAXY; LAYERS; YBA2CU3O7-DELTA; (001)SRTIO3; SUBSTRATE; TITANATE AB Adsorption-controlled growth conditions have been utilized to grow epitaxial, stoichiometric, c-axis oriented Bi4Ti3O12 thin films by reactive molecular beam epitaxy (MBE). We have studied samples grown on vicinal (miscut) and well-oriented (100) SrTiO3 substrates. There is a degradation in film properties as a function of step density (degree of miscut) on the SrTiO3 surface. The greater the degree of miscut of the SrTiO3, substrate, the less intense the X-ray diffraction peak intensities of the film become, and the wider are the rocking curve widths. The reduced film quality is further confirmed by ferroelectric hysteresis measurements. Films grown on miscut substrates have significant space charge contributions to the polarization, while films grown on well-oriented substrates show symmetric hysteresis loops with remanent polarizations approaching values obtained for bulk single crystals. The degradation of film properties is explained by considering the influence of steps at the SrTiO3, substrate surface on the electronic and crystallographic continuity in the ab plane of the deposited Bi4Ti3O12 films. (C) 1998 Published by Elsevier Science S.A. All rights reserved. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Schlom, DG (reprint author), Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RI Schlom, Darrell/J-2412-2013 OI Schlom, Darrell/0000-0003-2493-6113 NR 43 TC 7 Z9 7 U1 0 U2 7 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD NOV 6 PY 1998 VL 56 IS 2-3 BP 228 EP 233 DI 10.1016/S0921-5107(98)00244-X PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 150GK UT WOS:000077655700028 ER PT J AU Xiang, XD AF Xiang, XD TI Combinatorial synthesis and high throughput evaluation of functional oxides - A integrated materials chip approach SO MATERIALS SCIENCE AND ENGINEERING B-SOLID STATE MATERIALS FOR ADVANCED TECHNOLOGY LA English DT Article; Proceedings Paper CT 4th International Workshop on Oxide Electronics CY DEC 08-09, 1997 CL UNIV MARYLAND, COLLEGE PK, MARYLAND SP DARPA, Univ Maryland, NSF-MRSEC, Univ Maryland, Ctr Superconduct Res HO UNIV MARYLAND DE combinatorial synthesis; functional oxides; material chip fabrication ID NEAR-FIELD MICROSCOPE AB Integrated materials chip approach, in which large collections of different thin film metal oxides are integrated and synthesized on a small chip and screened for a particular functionality, is applied to discover or optimize superconductors, luminescent materials, magnetic materials, ferroelectrics and dielectrics. This technology promises to significantly increase the efficiency of the materials discovery and optimization process and improve our understanding of materials structure-property relationship. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Xiang, XD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM xdxiang@lbl.gov RI Xiang, Xiaodong/A-9445-2012; Xiang, Xiaodong/A-5936-2017 NR 9 TC 17 Z9 18 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5107 J9 MAT SCI ENG B-SOLID JI Mater. Sci. Eng. B-Solid State Mater. Adv. Technol. PD NOV 6 PY 1998 VL 56 IS 2-3 BP 246 EP 250 DI 10.1016/S0921-5107(98)00221-9 PG 5 WC Materials Science, Multidisciplinary; Physics, Condensed Matter SC Materials Science; Physics GA 150GK UT WOS:000077655700031 ER PT J AU Ren, ZF Huang, ZP Xu, JW Wang, JH Bush, P Siegal, MP Provencio, PN AF Ren, ZF Huang, ZP Xu, JW Wang, JH Bush, P Siegal, MP Provencio, PN TI Synthesis of large arrays of well-aligned carbon nanotubes on glass SO SCIENCE LA English DT Article ID FIELD-EMISSION AB Free-standing aligned carbon nanotubes have previously been grown. above 700 degrees C on mesoporous silica embedded with iron nanoparticles. Here, carbon nanotubes aligned over areas up to several square centimeters were grown on nickel-coated glass below 666 degrees C by plasma-enhanced hot filament chemical vapor deposition. Acetylene gas was used as the carbon source and ammonia gas was used asa catalyst and dilution gas. Nanotubes with controllable diameters from 20 to 400 nanometers and lengths from 0.1 to 50 micrometers were obtained. Using this method, large panels of aligned carbon nanotubes can be made under conditions that are suitable for device fabrication. C1 SUNY Buffalo, Mat Synth Lab, Dept Phys, Buffalo, NY 14260 USA. SUNY Buffalo, Mat Synth Lab, Dept Chem, Buffalo, NY 14260 USA. SUNY Buffalo, Ctr Adv Photon & Elect Mat, Buffalo, NY 14260 USA. SUNY Buffalo, Instrumentat Ctr, Buffalo, NY 14214 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ren, ZF (reprint author), SUNY Buffalo, Mat Synth Lab, Dept Phys, Nat Sci Complex, Buffalo, NY 14260 USA. RI Ren, Zhifeng/B-4275-2014 NR 16 TC 2057 Z9 2132 U1 62 U2 555 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 NOV 6 PY 1998 VL 282 IS 5391 BP 1105 EP 1107 DI 10.1126/science.282.5391.1105 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 136YY UT WOS:000076887700045 ER PT J AU Superko, HR AF Superko, HR TI Did grandma give you heart disease? The new battle against coronary artery disease SO AMERICAN JOURNAL OF CARDIOLOGY LA English DT Article; Proceedings Paper CT Symposium on Impact of Multiple Risk Factors on Coronary Artery Disease - Beyond Total Cholesterol CY NOV 05, 1998 CL CORNELL UNIV, COLL MED, NEW YORK, NEW YORK HO CORNELL UNIV, COLL MED ID LOW-DENSITY-LIPOPROTEIN; PRIMARY-PREVENTION TRIAL; LDL SUBCLASS PATTERN; RISK FACTOR; MYOCARDIAL-INFARCTION; PLASMA HOMOCYST(E)INE; ATHEROSCLEROSIS RISK; ELEVATED LIPOPROTEIN(A); POSTMENOPAUSAL WOMEN; PYRIDOXAL-PHOSPHATE AB Atherosclerosis/coronary artery disease (CAD) is largely a result of genetically linked dyslipidemias that can often be identified in clinical practice. Expression of these genetic traits is highly individual and can be affected by environmental factors such as diet and exercise. By understanding the heterogeneity of CAD, it becomes clear that all patients cannot be optimally managed with the same therapeutic regimen. Whereas elevated low-density lipoprotein (LDL) cholesterol is strongly correlated with CAD risk, reduction of LDL cholesterol alone is not an adequate strategy in many cases. Patients with the small, dense LDL of the atherogenic lipoprotein profile (pattern B) experience a 3-fold increased risk of CAD, and pattern B is also correlated with the development of type 2 diabetes. Likewise, elevated lipoprotein(a) increases atherosclerotic risk, particularly in the presence of other risk factors, and is predictive of CAD risk in bath women and men. Recent data show that the routine lipid profile-total cholesterol, triglycerides, LDL cholesterol, and high-density lipoprotein (HDL) cholesterol-does not detect the most common inherited dyslipidemias. Newer, more sophisticated tests, such as gradient gel electrophoresis, can detect disease-relevant lipidemic details, e.g., LDL subclass pattern, LDL particle diameter, and LDL subregions. Although these testing procedures are more expensive, their cost must be weighed against the potential lifelong cost of sometimes expensive drug treatment that may be avoided based on the results of such tests. Thus, by attending to the implications of family history, the interactions of genetic, metabolic, and environmental factors, and utilizing more targeted resting procedures, physicians can match the patient's disorder with specifically effective therapy while maintaining a cost-effective approach to disease management. (C) 1998 by Excerpta Medico, Inc. C1 Berkeley Heartlab Inc, San Mateo, CA 94402 USA. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Cholesterol Genet & Heart Dis Inst, Berkeley, CA 94720 USA. RP Superko, HR (reprint author), Berkeley Heartlab Inc, 1875 S Grant St,Suite 700, San Mateo, CA 94402 USA. NR 96 TC 16 Z9 16 U1 0 U2 0 PU EXCERPTA MEDICA INC PI NEW YORK PA 245 WEST 17TH STREET, NEW YORK, NY 10011 USA SN 0002-9149 J9 AM J CARDIOL JI Am. J. Cardiol. PD NOV 5 PY 1998 VL 82 IS 9A SI SI BP 34Q EP 46Q PG 13 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA 138NU UT WOS:000076979500006 PM 9819102 ER PT J AU Ding, CF Wang, XB Wang, LS AF Ding, CF Wang, XB Wang, LS TI Photoelectron spectroscopy of doubly charged anions: Intramolecular Coulomb repulsion and solvent stabilization SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Letter ID ELECTROSPRAY ION-SOURCE; NEGATIVE CLUSTER IONS; GAS-PHASE; HYDRATION; ENERGIES; SO4(2-) AB Photoelectron spectroscopy has been combined with an electrospray ionization technique to study gas-phase multiply charged anions and their intramolecular Coulomb repulsion and solvation stabilization. We report an initial study on a series of linear dicarboxylate dianions (DC2-), -O2C(CH2)(n)CO2- (n = 3-6), solvated by one and two waters. The second electron binding energy of DC2- decreases with decreasing aliphatic chain length owing to the increasing Coulomb repulsion between the two charges; the dianion with n = 2 has a binding energy close to zero and is not stable in the gas phase. We found that this dianion can be stabilized by one water, and in general the first water stabilizes the electron binding energy of DC2- by similar to 0.3 eV. The second water, however, was observed to show a much stronger stabilization effect (similar to 0.6 eV), suggesting that the two waters solvate the two carboxylate groups separately. C1 Washington State Univ, Dept Phys, Richland, WA 99352 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Wang, LS (reprint author), Washington State Univ, Dept Phys, Richland, WA 99352 USA. NR 31 TC 70 Z9 70 U1 2 U2 15 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 NOV 5 PY 1998 VL 102 IS 45 BP 8633 EP 8636 DI 10.1021/jp982698x PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 137VQ UT WOS:000076937700001 ER PT J AU Bai, S Yonker, CR AF Bai, S Yonker, CR TI Pressure and temperature effects on the hydrogen-bond structures of liquid and supercritical fluid methanol SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; SPIN-LATTICE RELAXATION; GAS-PHASE; MOLECULAR-DYNAMICS; NMR-SPECTROSCOPY; MIXTURES; C-13; DIFFRACTION; ALCOHOLS; ETHANOL AB The proton spin-lattice relaxation times and proton chemical shifts for the hydroxyl and methyl protons in methanol were measured at liquid and supercritical densities using capillary high-pressure NMR spectroscopy. The pressure range for the proton nuclear relaxation measurements was between 50 and 3500 bar over a temperature range of 298-573 K. The proton chemical shifts of methanol were investigated for a pressure range of 50-3500 bar and a temperature range of 298-773 K. Attempts were made to separate the contributions of the dipolar and spin-rotation interactions to the spin-relaxation processes at each thermodynamic condition over methanol densities ranging from liquid to supercritical fluid. An average number of hydrogen bonds per molecule in methanol and the apparent activation energy of the methyl group internal rotation have been extracted from the experimental relaxation data. The extracted quantities show a moderate pressure dependence in addition to temperature effects, which suggest that molecular packing effects on hydrogen-bonded methanol are important at higher pressures. A comparison between methanol and water at similar thermodynamic conditions was also made to obtain new insight into these two important supercritical solvents. C1 Pacific NW Lab, Environm & Energy Sci Div, Richland, WA 99352 USA. RP Yonker, CR (reprint author), Pacific NW Lab, Environm & Energy Sci Div, POB 999, Richland, WA 99352 USA. EM Clem.Yonker@pnl.gov NR 42 TC 60 Z9 60 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD NOV 5 PY 1998 VL 102 IS 45 BP 8641 EP 8647 DI 10.1021/jp981302e PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 137VQ UT WOS:000076937700003 ER PT J AU Chen, LH Lucia, LA Gaillard, ER Whitten, DG Icil, H Icli, S AF Chen, LH Lucia, LA Gaillard, ER Whitten, DG Icil, H Icli, S TI Photooxidation of a conjugated diene by an exciplex mechanism: Amplification via radical chain reactions in the perylene diimide-photosensitized oxidation of alpha-terpinene SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ELECTRON-TRANSFER; ION-PAIRS; SINGLET OXYGEN; SUPEROXIDE; CONTACT AB Irradiation of the perylene diimide (1) or 9,10-dicyanoanthracene (DCA) in the presence of alpha-terpinene (2-HH) in the presence of molecular oxygen leads to moderately efficient oxidation of 2-HH to p-cymene (2). Although 1 might be expected to photosensitize oxidations by the conventional "singlet oxygen" pathways, spectroscopic studies indicate that while oxygen can quench the fluorescent singlet of 1, no singlet oxygen is produced. 2-HH is also an efficient quencher of the fluorescent singlets of 1 and DCA and, for nonpolar solvents such as methylene chloride, in each case the quenching results in formation of an exciplex or contact radical ion pair. Under conditions where quenching by 2-HH to form the exciplex is complete, maximum quantum yields of 2 are obtained, thus indicating that the exciplex is the precursor to its formation. Nonproductive decay of the exciplex to starting materials is its major fate, thus the moderately high quantum efficiencies for formation of 2 require a mechanism involving amplification. Spin-trapping experiments suggest the role of hydroperoxy radicals and amplification by a radical chain mechanism involving these radicals and the intermediate 2-H-. is proposed. Possible paths for reaching these radicals from the exciplex are considered; either oxygen quenching of the exciplex or proton transfer within the exciplex followed by oxygen interception of the semireduced perylene diimide appear viable. For the reaction of DCA with 2-HH and oxygen, it is found that the much longer-lived exciplex undergoes quenching by oxygen. C1 Univ Rochester, Dept Chem, Rochester, NY 14627 USA. Univ Rochester, NSF, Ctr Photoinduced Charge Transfer, Rochester, NY 14627 USA. Eastern Mediterranean Univ, Dept Chem, Mersin 10, N Cyprus, Turkey. Ege Univ, Fac Sci, Dept Chem, TR-35100 Bornova, Izmir, Turkey. RP Whitten, DG (reprint author), Univ Calif Los Alamos Natl Lab, CST-1 MS J565, Los Alamos, NM 87545 USA. NR 31 TC 15 Z9 15 U1 2 U2 13 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 NOV 5 PY 1998 VL 102 IS 45 BP 9095 EP 9098 DI 10.1021/jp983346t PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 137VQ UT WOS:000076937700062 ER PT J AU Adzic, RR Wang, JX AF Adzic, RR Wang, JX TI Configuration and site of O-2 adsorption on the Pt(111) electrode surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SINGLE-CRYSTAL SURFACES; ANION ADSORPTION; MOLECULAR-OXYGEN; ACID-SOLUTIONS; METAL ADATOMS; REDUCTION; PLATINUM; HYDROGEN; ELECTROCATALYSIS; DEPOSITION AB The inhibition of O-2 reduction On a Pt(lll) electrode surface with Ag adatoms has been studied to gain information on the type of O-2 adsorption during the reaction. A pronounced inhibition is observed upon adsorption of Ag submonolayers, and a complete inhibition is caused by underpotential deposition of a pseudomorphic Ag monolayer and of an incommensurate hexagonal bilayer. Electrochemical and in situ surface X-ray scattering techniques were used to obtain kinetic and structural data. Statistical models for the inhibition of O-2 reduction caused at submonolayers of Ag adatoms residing on top, bridge, and hollow sites of Pt(lll) for O-2 adsorbed on the same type of sites in three different configurations have been compared with the experimental data. Analysis of the extent of the inhibition of O-2 reduction as a function of the Ag coverage shows that the data are best interpreted with O-2 adsorbed at a bridge site. C1 Brookhaven Natl Lab, Dept Appl Sci, Div Chem Sci, Upton, NY 11973 USA. RP Adzic, RR (reprint author), Brookhaven Natl Lab, Dept Appl Sci, Div Chem Sci, Upton, NY 11973 USA. RI Wang, Jia/B-6346-2011 NR 30 TC 49 Z9 49 U1 3 U2 33 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 NOV 5 PY 1998 VL 102 IS 45 BP 8988 EP 8993 DI 10.1021/jp981057z PG 6 WC Chemistry, Physical SC Chemistry GA 137VK UT WOS:000076937200009 ER PT J AU Rao, RM Dvorak, J Beuhler, RJ White, MG AF Rao, RM Dvorak, J Beuhler, RJ White, MG TI State-selective laser photochemistry of formaldehyde on Ag(111) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PULSED FREE JETS; SURFACE PHOTOCHEMISTRY; INDUCED POLYMERIZATION; CO; PT(111); DESORPTION; MOLECULES; PHOTODISSOCIATION; PHOTODESORPTION; DISTRIBUTIONS AB State-selective (VUV + UV) resonant multiphoton ionization is used to measure the state- and energy-distributions of the gas-phase products which accompany the UV photoinduced polymerization of formaldehyde on Ag(lll). At 355 nm, only direct desorption of H2CO is observed, whereas both CO product formation and H2CO desorption are found at 266 nm. The rotational state and translational energies of the desorbed CO products exhibit a "fast" channel associated with a prompt fragmentation process and a "slow" channel in near-thermal equilibrium with the Ag surface. No gas-phase hydrogen products (H atoms, H-2) were detected during UV exposure, but H-2 desorption is observed during breakup of the polymer above 200 K. The time-dependent desorption yields for both slow CO and H2CO are strongly temperature dependent and reflect the rate of polymerization. A simple kinetic model is used to describe the competing processes of desorption, fragmentation, and polymerization which ultimately result from the decay or fragmentation of an H2CO(a)(-) Or other H2CO(a) excited-state species. In combination with depletion rates measured over the temperature range 30-95 K, the kinetic model results in an activation energy for polymerization of 0.90 +/- 0.06 kcal/mol. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP White, MG (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM white@dynamics.chm.bnl.gov NR 54 TC 5 Z9 5 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD NOV 5 PY 1998 VL 102 IS 45 BP 9050 EP 9060 DI 10.1021/jp9828484 PG 11 WC Chemistry, Physical SC Chemistry GA 137VK UT WOS:000076937200017 ER PT J AU Norby, RJ Cotrufo, MF AF Norby, RJ Cotrufo, MF TI Global change - A question of litter quality SO NATURE LA English DT Editorial Material ID ELEVATED CO2; DECOMPOSITION C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. Univ Naples 2, Dipartimento Sci Ambientali, I-81100 Caserta, Italy. RP Norby, RJ (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. EM rjn@ornl.gov; fcotrufo@tin.it RI Norby, Richard/C-1773-2012; Cotrufo, M. Francesca/C-1614-2013 OI Norby, Richard/0000-0002-0238-9828; Cotrufo, M. Francesca/0000-0002-6191-8953 NR 12 TC 114 Z9 122 U1 5 U2 40 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 5 PY 1998 VL 396 IS 6706 BP 17 EP 18 DI 10.1038/23812 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 136HE UT WOS:000076852700023 ER PT J AU Nielsen, MA Knill, E Laflamme, R AF Nielsen, MA Knill, E Laflamme, R TI Complete quantum teleportation using nuclear magnetic resonance SO NATURE LA English DT Article ID ENTANGLEMENT; STATE; COMPUTATION; CHANNELS AB Quantum-mechanical systems have information processing capabilities(1,2) that are not possible with classical devices, One example is quantum teleportation(3), in which the quantum state of a system is transported from one location to another without moving through the intervening space. But although partial implementations(4,5) of quantum teleportation over macroscopic distances have been achieved using optical systems, the final stage of the teleportation procedure-which allows the complete recovery of the original state-was omitted. Here we report an experimental implementation of full quantum teleportation over interatomic distances using liquid-state nuclear magnetic resonance. We achieve teleportation of the quantum state of a carbon nucleus to a hydrogen nucleus in molecules of trichloroethylene, by exploiting natural phase decoherence of the carbon nuclei. Such a teleportation scheme may be used as a subroutine in larger quantum computations, or for quantum communication. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ New Mexico, Dept Phys & Astron, Albuquerque, NM 87131 USA. RP Nielsen, MA (reprint author), Univ Calif Los Alamos Natl Lab, MS B-288, Los Alamos, NM 87545 USA. EM mnielsen@theory.caltech.edu NR 27 TC 388 Z9 424 U1 1 U2 22 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 5 PY 1998 VL 396 IS 6706 BP 52 EP 55 DI 10.1038/23891 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 136HE UT WOS:000076852700048 ER PT J AU Davis, WB Svec, WA Ratner, MA Wasielewski, MR AF Davis, WB Svec, WA Ratner, MA Wasielewski, MR TI Molecular-wire behaviour in p-phenylenevinylene oligomers SO NATURE LA English DT Article ID ELECTRON-TRANSFER; DISTANCE DEPENDENCE; COMPLEXES; POLYENES; SYSTEMS; SPACERS; LENGTH; RATES AB Electron transfer from electron-donor to electron-acceptor molecules via a molecular 'bridge' is a feature of many biological and chemical systems. The electronic structure of the bridge component in donor-bridge-acceptor (DBA) systems is known to play a critical role in determining the ease of electron transfer(1,2). In most DBA systems, the rate at which electron transfer occurs scales exponentially with the donor-acceptor distance-effectively the length of the bridge molecule. But theory predicts that regimes exist wherein the distance dependence may be very weak, the bridge molecules essentially acting as incoherent molecular wires(3-6). Here we show how these regimes can be accessed by molecular design. We have synthesized a series of structurally well-defined DBA molecules that incorporate tetracene as the donor and pyromellitimide as the acceptor, linked by p-phenylenevinylene oligomers of various lengths. Photoinduced electron transfer in this series exhibits very weak distance dependence for donor-acceptor separations as large as 40 Angstrom, with rate constants of the order of 10(11) s(-1). These findings demonstrate the importance of energy matching between the donor and bridge components for achieving molecular-wire behaviour. C1 Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Wasielewski, MR (reprint author), Northwestern Univ, Dept Chem, Evanston, IL 60208 USA. EM wasielew@chem.nwu.edu NR 31 TC 591 Z9 595 U1 7 U2 72 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD NOV 5 PY 1998 VL 396 IS 6706 BP 60 EP 63 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA 136HE UT WOS:000076852700051 ER PT J AU Helgesson, J Randrup, J AF Helgesson, J Randrup, J TI Transport simulations with pi and Delta in-medium properties SO PHYSICS LETTERS B LA English DT Article DE spin-isospin modes; transport simulation; in-medium properties; heavy-ion collisions; delta-hole model; pion production ID HEAVY-ION COLLISIONS; SPIN-ISOSPIN MODES; ELASTIC-SCATTERING; DILEPTON PRODUCTION; PIONIC MODES; ENERGIES; MATTER AB Transport simulations including in-medium properties derived in a microscopic pi + NN-1 + Delta N-1 model in infinite nuclear matter are presented. In-medium pion dispersion relations, partial Delta decay widths, pion absorption cross sections and Delta cross sections are incorporated into the transport description by means of a local-density approximation. Strong modifications of pi and Delta production and absorption rates are found, but only small effects on pion observables. (C) 1998 Elsevier Science B.V. Ail rights reserved. C1 European Ctr Studies Theoret Nucl Phys & Related, ECT, Trento, Italy. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Malmo Univ, Sch Engn & Econ, S-20506 Malmo, Sweden. NR 31 TC 6 Z9 6 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 NOV 5 PY 1998 VL 439 IS 3-4 BP 243 EP 250 DI 10.1016/S0370-2693(98)01109-5 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 138HX UT WOS:000076967400002 ER PT J AU Cheng, HC Dobrescu, BA Matchev, KT AF Cheng, HC Dobrescu, BA Matchev, KT TI A chiral supersymmetric standard model SO PHYSICS LETTERS B LA English DT Article ID MU-PROBLEM; FERMILAB TEVATRON; SYMMETRY-BREAKING; LIGHT GRAVITINO; STRING MODELS; GAUGE; COLLIDER; U(1); SIGNATURES; HIERARCHY AB We propose a supersymmetric extension of the Standard Model with an extra U(1) gauge symmetry, so that all supersymmetric mass terms, including the mu-term, are forbidden by the gauge symmetries. Supersymmetry is broken dynamically which results in U(1) breaking and generation of realistic mu term and soft breaking masses. The additional fields required to cancel the U(I) anomalies are identified with the messengers of supersymmetry breaking. The gaugino masses arise as in the usual gauge mediated scenario, while squarks and sleptons receive their masses from both the U(1) D-term and the two-loop gauge mediation contributions. The scale of supersymmetry breaking in this model can be below 10(6) GeV, yielding collider signatures with decays to goldstinos inside the detector. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Cheng, HC (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 36 TC 44 Z9 44 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 NOV 5 PY 1998 VL 439 IS 3-4 BP 301 EP 308 DI 10.1016/S0370-2693(98)01052-1 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 138HX UT WOS:000076967400011 ER PT J AU Blotz, A Shuryak, E AF Blotz, A Shuryak, E TI Instanton-induced charm contribution to polarized deep-inelastic scattering SO PHYSICS LETTERS B LA English DT Article ID PROTON AB Recent data on B decays involving eta' may be explained if the singlet axial current of charmed quarks has a large matrix element to eta', and instantons were shown to be able to generate this effect. We study the magnitude of charm contributions to nucleon polarized structure functions generated in a similar way. Comparing the charm contribution, which is related to a dim(6) gluonic operator, to that of light quarks, which are related by the anomaly equation to G (G) over tilde, we found that Delta c/Delta Sigma similar or equal to -0.03. Future experiments like COMPASS at CERN identifying charm production in DIS can measure this "intrinsic polarized charm" component of the nucleon. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. SUNY Stony Brook, Dept Phys Astron, Stony Brook, NY 11794 USA. RP Blotz, A (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, T5 MS B283, Los Alamos, NM 87545 USA. NR 15 TC 10 Z9 10 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 NOV 5 PY 1998 VL 439 IS 3-4 BP 415 EP 420 DI 10.1016/S0370-2693(98)01051-X PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 138HX UT WOS:000076967400027 ER PT J AU Rodriguez, JA Jirsak, T Chaturvedi, S Hrbek, J AF Rodriguez, JA Jirsak, T Chaturvedi, S Hrbek, J TI Surface chemistry of SO2 on Sn and Sn/Pt(111) alloys: Effects of metal-metal bonding on reactivity toward sulfur SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID BIMETALLIC SURFACES; ELECTRONIC-PROPERTIES; CO-CHEMISORPTION; PROMOTED SULFIDATION; CHEMICAL-PROPERTIES; NITRIC-OXIDE; PT(111); ADSORPTION; PLATINUM; PHOTOEMISSION AB The surface chemistry of SO2 on polycrystalline Sn, Pt(lll), and a (root 3 x root 3)R30 degrees-Sn/Pt(lll) surface alloy has been investigated using synchrotron-based high-resolution photoemission and ab initio self-consistent field calculations. Metallic tin has a large chemical affinity for SO2. At 100-150 K, SO2 disproportionates on polycrystalline tin forming multilayers of SO3 (2SO(2,a) --> SOgas + SO3,a). At these low temperatures, the full dissociation of SO2 (SO2,a --> S-a + 2O(a)) is minimal. As the temperature is raised to 300 K, the SO3 decomposes, yielding SO4, S, and O on the surface. Pure tin exhibits a much higher reactivity toward SO2 than late transition metals (Ni, Pd, Pt, Cu, Ag, Au) In contrast, tin atoms in contact with Pt(111) interact weakly with SO2. A (root 3 x root 3)R30 degrees-Sn/Pt(111) alloy is much less reactive toward SO2 than polycrystalline tin or clean Pt(lll). At 100 K, SO2 adsorbs molecularly on (root 3 x root 3)R30 degrees-Sn/Pt( ill). Most of the adsorbed SO2 desorbs intact from the surface (250-300K), whereas a small fraction dissociates into S and O. The drastic drop in reactivity when going from pure tin to the (root 3 x root 3)R30 degrees-Sn/Pt(111) alloy can be attributed to a combination of ensemble and electronic effects. On the other hand, the low reactivity of the Pt sites in (root 3 x root 3)R30 degrees-Sn/Pt(lll) with respect to P(111) is a consequence of electronic effects. The Pt-Sn bond is complex, involving a Sn(5s,5p)--> Pt(6s,6p) charge transfer and a Pt(5d)--> Pt(6s,6p) rehybridization that localize electrons in the region between the metal centers. These phenomena reduce the electron donor ability of Pt and Sn, and both metals are not able to respond in an effective way to the presence of SO2. The Sn/Pt system illustrates how a redistribution of electrons that occurs in bimetallic bonding can be useful for the design of catalysts that have a remarkably low reactivity toward SO2 and for controlling sulfur poisoning. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Rodriguez, JA (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. EM rodrigez@bnl.gov RI Hrbek, Jan/I-1020-2013 NR 72 TC 65 Z9 65 U1 2 U2 12 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 NOV 4 PY 1998 VL 120 IS 43 BP 11149 EP 11157 DI 10.1021/ja982174a PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA 136JE UT WOS:000076855000017 ER PT J AU Liang, L Feng, XD Liu, J Rieke, PC Fryxell, GE AF Liang, L Feng, XD Liu, J Rieke, PC Fryxell, GE TI Reversible surface properties of glass plate and capillary tube grafted by photopolymerization of N-isopropylacrylamide SO MACROMOLECULES LA English DT Article ID ULTRAFILTRATION MEMBRANES; TEMPERATURE; POLY(N-ISOPROPYLACRYLAMIDE); SEPARATION; GELS AB A new, simple, and effective method to modify the surface of glass plate and quartz capillary tube by ultraviolet (UV) photopolymerization of N-isopropylacrylamide (NIPAAm) has been developed. A photosensitizer, silane coupling agent with the dithiocarbamate group, was synthesized by the condensation re action between chloropropyltrimethoxysilane and sodium N,N'-diethyldithiocarbamate. The thiocarbamate groups were installed on the glass surface by coupling the silane agent with the hydroxyl groups on the glass surface. Subsequently, the silane-modified surface was photografted by NIPAAm in the presence of N,N-methylenebisacrylamide. The characteristics of the glass surfaces were examined by scanning electronic microscopy (SEM) and the static and dynamic contact angle techniques. The thickness of grafted PNIPAAm film is less than 320 nm, and the surface showed a completely hydrophilic nature at about room temperature and a hydrophobic nature above 40 degrees C. The water meniscus height in a capillary tube (2 mm in diameter), whose wall was coated with a cross-linked NIPAAm layer, was rose to 7 mm by changing the temperature of the water in contact with a capillary tube by about 20 degrees C. The rapid and remarkable change in surface properties with the temperature change makes it applicable as actuators, modulators, and the antifouling surface and microchannel of separation membranes. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Liang, L (reprint author), Ferro Corp, 7500 Pleasant Valley Rd, Independence, OH 44131 USA. EM Fengx@FERRO.com NR 32 TC 110 Z9 115 U1 2 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD NOV 3 PY 1998 VL 31 IS 22 BP 7845 EP 7850 PG 6 WC Polymer Science SC Polymer Science GA 136JA UT WOS:000076854600037 ER PT J AU Matsumoto, K Tucker, JD AF Matsumoto, K Tucker, JD TI Detection of structural chromosome damage in rat interphase cells using region-specific fluorescence in situ hybridization probes developed by microdissection SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article DE chromosome aberrations; interphase; region-specific DNA probes; multi-color FISH; rat ID INSITU HYBRIDIZATION; RAPID GENERATION; PAINTING PROBES; HUMAN GENOME; DNA PROBES; AMPLIFICATION; ABERRATIONS; RADIATION; BAND; FISH AB Cytogenetic analysis using fluorescence in situ hybridization (FISH) was employed to detect structural chromosome aberrations in interphase. We generated DNA probes specific for rat chromosome regions 1q11-12, 1q31-35 and 1q51-53 by microdissection and degenerate oligonucleotide-primed PCR. Targeted regions were labeled in unique colors by FISH. Abnormal cells were identified on the basis of alterations in the physical distance between the hybridization signals. To evaluate the ability of these probes to quantify chromosome aberrations in interphase, rats were acutely exposed whole-body to O, 1, 2, 3 or 4 Gy of Cs-137 gamma rays. Eight days later, peripheral blood, bone marrow, lung and pancreas were removed and hybridized with the probes. Multi-color FISH analysis showed dose-responsive frequencies of abnormal interphase nuclei in peripheral blood and bone marrow cells. In lung and pancreas, on the contrary, no increase in the frequency of the abnormal interphases was observed. However, chromosome damage was observed when primary lung cells, obtained from rats irradiated 8 days previously, were cultured for three days. Detection of rearranged signals after in vitro tissue culture was attributed to the movement of chromosome domains that accompanies mitosis. The use of region-specific painting probes appears useful for detecting structural chromosome damage in interphase cells of rat tissues, although further optimization is still needed to improve the method. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, Livermore, CA 94551 USA. RP Matsumoto, K (reprint author), Inst Environm Toxicol, Div Toxicol, 2-772 Suzuki Cho, Tokyo 1870011, Japan. FU NCI NIH HHS [P01 CA-55861] NR 43 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD NOV 3 PY 1998 VL 421 IS 2 BP 179 EP 190 DI 10.1016/S0027-5107(98)00164-X PG 12 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA 134ZQ UT WOS:000076774400004 PM 9852991 ER PT J AU Mason, TA AF Mason, TA TI Simulation of the variation of material tensor properties of polycrystals achieved through modification of the crystallographic texture SO SCRIPTA MATERIALIA LA English DT Article ID ELASTIC PROPERTIES; CONSTANTS C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Mason, TA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 23 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD NOV 3 PY 1998 VL 39 IS 11 BP 1537 EP 1543 DI 10.1016/S1359-6462(98)00345-5 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA 139RC UT WOS:000077042300008 ER PT J AU Miller, DG AF Miller, DG TI A liquid state least-squares procedure for obtaining solid state multicomponent diffusion coefficients from diffusion couples SO ACTA MATERIALIA LA English DT Article ID ROOT DIFFUSIVITY; TERNARY; PROFILES; ALLOYS AB A procedure is developed for analyzing combined concentration profiles from multicomponent solid-state diffusion data obtained with free-diffusion boundary conditions. This procedure is exactly analogous to the analysis of liquid-state diffusion data obtained from free-diffusion refractive-index profiles (e.g. from Rayleigh interferometry). All data from all couples are least-squared together to characterize the diffusion coefficient matrix. Different profile weightings provide interesting alternatives, as well as diagnostics. Symmetric averagings are shown to eliminate or reduce effects of concentration dependence. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Miller, DG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 23 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 2 PY 1998 VL 46 IS 17 BP 5993 EP 5999 DI 10.1016/S1359-6454(98)00284-5 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 144GH UT WOS:000077305300002 ER PT J AU Leggoe, JW Mammoli, AA Bush, MB Hu, XZ AF Leggoe, JW Mammoli, AA Bush, MB Hu, XZ TI Finite element modelling of deformation in particulate reinforced metal matrix composites with random local microstructure variation SO ACTA MATERIALIA LA English DT Article ID SIC/AL COMPOSITES; 2-PHASE MATERIALS; BEHAVIOR; GROWTH AB Deformation in particulate reinforced metal matrix composites (PR MMCs) with locally varying reinforcement volume fraction has been modelled using a two-scale finite element approach. The responses of axisymmetric unit cell models were used to define the constitutive response of mesoscale regions possessing varying volume fractions. Macroscale response was then investigated using two- and three-dimensional "random arrays" of finite elements, in which element properties were randomly assigned in line with a Gaussian distribution. Two-dimensional random arrays developed non-uniform strain fields, severe strain localization ensuing as straining proceeded. Two-dimensional random arrays are, however, inappropriate for modelling the three-dimensional microstructure of PR MMCs. Three-dimensional random arrays also developed non-uniform strain fields, but severe strain localization did not arise. Reinforcement clustering was simulated by varying the standard deviation in element volume fraction. Yield stress, strain hardening and elastic modulus were all found to increase as the severity of clustering iri;creased. (C) 1998 Acta Metallurgica he. Published by Elsevier Science Ltd. All rights reserved. C1 Univ Western Australia, Dept Mech & Mat Engn, Nedlands, WA 6009, Australia. RP Leggoe, JW (reprint author), Univ Calif Los Alamos Natl Lab, TSA-7,Mail Stop F609, Los Alamos, NM 87545 USA. RI Hu, Xiaozhi /H-4353-2011 NR 29 TC 35 Z9 42 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 2 PY 1998 VL 46 IS 17 BP 6075 EP 6088 DI 10.1016/S1359-6454(98)00279-1 PG 14 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 144GH UT WOS:000077305300010 ER PT J AU Cohron, JW Lin, Y Zee, RH George, EP AF Cohron, JW Lin, Y Zee, RH George, EP TI Room-temperature mechanical behavior of FeAl: Effects of stoichiometry, environment, and boron addition SO ACTA MATERIALIA LA English DT Article ID FRACTURE-BEHAVIOR; STRAIN-RATE; DOPED FEAL; DUCTILITY; NI3AL; EMBRITTLEMENT; HYDROGEN; ALLOYS; WATER; AL AB The intrinsic ductility of FeAl (in ultrahigh vacuum) decreases with increasing Al content, from around 16% in Fe-37A1 to zero in Fe-48A1. The sharpest decline occurs around the composition where the fracture mode changes from transgranular to intergranular. Boron shifts this ductile-brittle transition to higher Al levels by segregating to the grain boundaries and suppressing grain-boundary fracture. However, its effectiveness decreases with increasing Al concentration, even though the amount of B segregating to the grain boundaries remains the same, independent of alloy stoichiometry. Consequently, even the B-doped alloys become brittle and fracture intergranularly as the stoichiometric composition is approached. Low-pressure hydrogen embrittles FeAl, although not as severely as atmospheric moisture. Environmental embrittlement is most noticeable in Fe-rich FeAl; with increasing Al concentration, the grain boundaries become intrinsically weak, and brittle fracture persists even after environmental effects are eliminated. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Auburn Univ, Mat Engn Program, Auburn, AL 36849 USA. RP George, EP (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI George, Easo/L-5434-2014 NR 33 TC 39 Z9 42 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD NOV 2 PY 1998 VL 46 IS 17 BP 6245 EP 6256 DI 10.1016/S1359-6454(98)00254-7 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA 144GH UT WOS:000077305300024 ER PT J AU Ruvimov, S Liliental-Weber, Z Washburn, J Qiao, D Lau, SS Chu, PK AF Ruvimov, S Liliental-Weber, Z Washburn, J Qiao, D Lau, SS Chu, PK TI Microstructure of Ti/Al ohmic contacts for n-AlGaN SO APPLIED PHYSICS LETTERS LA English DT Article ID GAN; RESISTANCE AB Transmission electron microscopy was employed to evaluate the microstructure of Al/Ti ohmic contacts to AlGaN/GaN heterostructure field-effect transistor structures. Contact resistance was found to depend on the structure and composition of the metal and AlGaN layers, and on atomic structure of the interface. A 15-25-nm-thick interfacial AlTi2N layer was observed at the contact-AlGaN interface. Formation of such nitrogen-containing layers appears to be essential for ohmic behavior on n-type III-nitride materials suggesting a tunneling contact mechanism. Contact resistivity was found to increase with Al fraction in the AlGaN layer. (C) 1998 American Institute of Physics. [S0003-6951(98)01244-3]. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif San Diego, La Jolla, CA 92093 USA. City Univ Hong Kong, Hong Kong, Hong Kong. RP Ruvimov, S (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Chu, Paul/B-5923-2013 OI Chu, Paul/0000-0002-5581-4883 NR 15 TC 93 Z9 99 U1 3 U2 16 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 NOV 2 PY 1998 VL 73 IS 18 BP 2582 EP 2584 DI 10.1063/1.122512 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900014 ER PT J AU Yan, Y Pennycook, SJ Dai, J Chang, RPH Wang, A Marks, TJ AF Yan, Y Pennycook, SJ Dai, J Chang, RPH Wang, A Marks, TJ TI Polytypoid structures in annealed In2O3-ZnO films SO APPLIED PHYSICS LETTERS LA English DT Article ID TRANSPARENT; CRYSTALS; SYSTEM AB Atomic-resolution Z-contrast images demonstrate unambiguously that the annealed, metalorganic chemical vapor deposition derived transparent In2O3-ZnO films have a polytypoid microstructure, consisting of ZnO slabs of variable width separated by single In-O octahedral layers. These In-O layers induce a polarity inversion in the two adjacent ZnO layers, which is reversed again by a mirror domain boundary inside each ZnO slab. (C) 1998 American Institute of Physics. [S0003-6951(98)01444-2]. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Northwestern Univ, Mat Res Ctr, Evanston, IL 60208 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 RI Chang, R.P.H/B-7505-2009; Dai, Jiyan/I-7098-2013 OI Dai, Jiyan/0000-0002-7720-8032 NR 14 TC 61 Z9 62 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 NOV 2 PY 1998 VL 73 IS 18 BP 2585 EP 2587 DI 10.1063/1.122513 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900015 ER PT J AU Merkulov, VI Lowndes, DH Jellison, GE Puretzky, AA Geohegan, DB AF Merkulov, VI Lowndes, DH Jellison, GE Puretzky, AA Geohegan, DB TI Structure and optical properties of amorphous diamond films prepared by ArF laser ablation as a function of carbon ion kinetic energy SO APPLIED PHYSICS LETTERS LA English DT Article ID GROWTH AB Amorphous carbon films with variable sp(3) content were produced by ArF (193 nm) pulsed laser deposition. Electron energy loss spectroscopy and spectroscopic ellipsometry were employed to systematically study changes in the bonding and optical properties of the carbon films as a function of the kinetic energy of ablated C ions, which was measured using an ion probe. The measurements reveal that the films with the most diamond-like properties are obtained at the C ion kinetic energy of similar to 90 eV. In contrast to measurements made as a function of laser fluence, ion probe measurements of kinetic energy are a convenient as well as more accurate and fundamental method for monitoring deposition conditions, with the advantage of being readily transferable for interlaboratory comparisons. (C) 1998 American Institute of Physics. [S0003-6951(98)03044]. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Merkulov, VI (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Puretzky, Alexander/B-5567-2016; Geohegan, David/D-3599-2013 OI Puretzky, Alexander/0000-0002-9996-4429; Geohegan, David/0000-0003-0273-3139 NR 18 TC 64 Z9 64 U1 0 U2 7 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 NOV 2 PY 1998 VL 73 IS 18 BP 2591 EP 2593 DI 10.1063/1.122515 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900017 ER PT J AU Klimov, VI Schwarz, CJ McBranch, DW White, CW AF Klimov, VI Schwarz, CJ McBranch, DW White, CW TI Initial carrier relaxation dynamics in ion-implanted Si nanocrystals: Femtosecond transient absorption study SO APPLIED PHYSICS LETTERS LA English DT Article ID POROUS SILICON; VISIBLE PHOTOLUMINESCENCE; LIGHT-EMISSION; LUMINESCENCE; MECHANISM AB Transient absorption spectra of ion-implanted Si nanocrystals (NCs) exhibit two picosecond photoinduced absorption features, attributed to carriers in NC quantized states (high-energy band) and Si/SiO2 interface states (low-energy band). Fast relaxation of the high-energy band indicates that populations of quantized states are short lived and decay on the sub-10-ps time scale due to efficient surface trapping. This shows that the red emission in our samples is not due to carriers in quantized states but rather is a result of deactivation of surface traps. (C) 1998 American Institute of Physics. [S0003-6951(98)00544-0]. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87544 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Klimov, VI (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, CST-6,MS-J585, Los Alamos, NM 87544 USA. RI Lujan Center, LANL/G-4896-2012 NR 18 TC 70 Z9 70 U1 2 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 NOV 2 PY 1998 VL 73 IS 18 BP 2603 EP 2605 DI 10.1063/1.122519 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900021 ER PT J AU Li, DQ Bishop, A Gim, Y Shi, XB Fitzsimmons, MR Jia, QX AF Li, DQ Bishop, A Gim, Y Shi, XB Fitzsimmons, MR Jia, QX TI Conduction properties of metal organic monolayer semiconductor heterostructures SO APPLIED PHYSICS LETTERS LA English DT Article AB We have fabricated and characterized rectifying devices made of metal/organic monolayer/semiconductor heterostructures. The devices consist of an organic barrier layer sandwiched between an aluminum (Al) metal contact and a p-type Si semiconductor. The barrier materials were chosen from three types of self-assembled monolayers (SAMs) with different electronic properties: (1) wide-band gap poly(diallydimethyl ammonium) chloride (PDDA) 2, narrow-band gap PDDA/NiPc (nickel phthalocyanine tetrasulfonate), and donor type PDDA/PPP (poly p-quaterphenylene-disulfonic-dicarboxylic acid). From current-voltage (I - V) measurements at room temperature, we have found the turn-on voltage of the devices can be tuned by varying the structure, hence electronic properties, of the organic monolayers, and that there exists a power-law dependence of I on V, I proportional to V-alpha, with the exponent alpha = 2.2 for PDDA, 2.7 for PDDA/NiPc, and 1.44 for PDDA/PPP as the barrier layer, respectively. Our results imply that the transport properties are controlled by both the electronic properties of the SAMs and those of the metal and semiconductor, as indicated by the power-law dependence of the I - V characteristics. (C) 1998 American Institute of Physics. [S0003-6951(98)03744-9] C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Li, DQ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012; Jia, Q. X./C-5194-2008 NR 10 TC 27 Z9 27 U1 0 U2 3 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 NOV 2 PY 1998 VL 73 IS 18 BP 2645 EP 2647 DI 10.1063/1.122540 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900035 ER PT J AU Cheong, HM Ahrenkiel, SP Hanna, MC Masccarenhas, A AF Cheong, HM Ahrenkiel, SP Hanna, MC Masccarenhas, A TI Phonon signatures of spontaneous CuPt ordering in Ga0.47In0.53As/InP SO APPLIED PHYSICS LETTERS LA English DT Article ID RAMAN-SCATTERING; ALLOY SEMICONDUCTORS; GAINP2; MODES; SPECTRA; IN0.53GA0.47AS AB Polarized Raman scattering spectra of spontaneously ordered Ga0.47In0.53As alloys, combined with low-temperature photoluminescence and transmission electron microscopy, are used to find a unique phonon signature of CuPtB-type ordering. In the Raman spectra of ordered alloys, a new phonon peak that is absent in the spectrum of the random alloy appears at 181 cm(-1). The intensity of this peak correlates with the degree of ordering inferred from electron diffraction measurements. We propose that Raman scattering measurements can be used as a nondestructive probe to detect spontaneous ordering in this alloy. (C) 1998 American Institute of Physics. [S0003-6951(98)02244-X] C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Cheong, HM (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 NR 24 TC 11 Z9 11 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 NOV 2 PY 1998 VL 73 IS 18 BP 2648 EP 2650 DI 10.1063/1.122541 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900036 ER PT J AU Park, SY Isobe, T Senna, M Weeks, RA Zuhr, RA AF Park, SY Isobe, T Senna, M Weeks, RA Zuhr, RA TI Effects of KrF laser irradiation on Bi nanoclusters embedded in a-SiO2 by ion implantation SO APPLIED PHYSICS LETTERS LA English DT Article ID GLASS AB Bismuth nanoclusters have been formed in optical grade silica glass (Corning 7940) by ion implantation which formed localized Bi:SiO2 composite in the near-surface region. Subsequent irradiation with 248 nm KrF excimer laser light modifies the distribution and chemical states of the implanted bismuth in the composite. Excimer laser irradiation causes not only photochemical reactions in the composite leaving a thin film of bismuth oxide on the surface, but also removal of the precipitated particles by both thermal and nonthermal desorption mechanisms from the surface. (C) 1998 American Institute of Physics. [S0003-6951(98)02344-4] C1 Keio Univ, Fac Sci & Technol, Dept Appl Chem, Yokohama, Kanagawa 2238522, Japan. Vanderbilt Univ, Dept Appl & Engn Sci, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Park, SY (reprint author), Keio Univ, Fac Sci & Technol, Dept Appl Chem, Yokohama, Kanagawa 2238522, Japan. NR 14 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD NOV 2 PY 1998 VL 73 IS 18 BP 2687 EP 2689 DI 10.1063/1.122554 PG 3 WC Physics, Applied SC Physics GA 131DR UT WOS:000076560900049 ER PT J AU Lee, TC AF Lee, TC TI Biosynthesis and possible biological functions of plasmalogens SO BIOCHIMICA ET BIOPHYSICA ACTA-LIPIDS AND LIPID METABOLISM LA English DT Review DE ethanolamine plasmalogen; choline plasmalogen; biosynthesis; function; ether lipid ID PLATELET-ACTIVATING-FACTOR; GUINEA-PIG LIVER; DIHYDROXYACETONE PHOSPHATE ACYLTRANSFERASE; CALCIUM-INDEPENDENT PHOSPHOLIPASE; CULTURED RAT HEPATOCYTES; CANINE KIDNEY-CELLS; ETHANOLAMINE PLASMALOGEN; PEROXISOMAL DISORDERS; CHOLINE PLASMALOGENS; LIPID-PEROXIDATION C1 Oak Ridge Associated Univ, Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. RP Lee, TC (reprint author), Oak Ridge Associated Univ, Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. FU NHLBI NIH HHS [HL52492] NR 83 TC 69 Z9 76 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0005-2760 J9 BBA-LIPID LIPID MET JI Biochim. Biophys. Acta-Lipids Lipid Metab. PD NOV 2 PY 1998 VL 1394 IS 2-3 BP 129 EP 145 DI 10.1016/S0005-2760(98)00107-6 PG 17 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 136CW UT WOS:000076841500001 PM 9795186 ER PT J AU Chen, MJ Utschig, LM Rathke, JW AF Chen, MJ Utschig, LM Rathke, JW TI Paramagnetic Rh(III) complexes from reactions of phosphines with hydride-bridged and nonbridged rhodium phthalocyanine dimers: Metal-to-ligand charge transfer induced by phosphines SO INORGANIC CHEMISTRY LA English DT Article ID REACTIVITY AB The paramagnetic rhodium phthalocyanine complex (RPc)(PMe3)(2)Rh (4) (RPc = dianion of 1,4,8,11,15,18,22,25-octa-n-pentylphthalocyanine) has been prepared by the reaction of trimethylphosphine (PMe3) with hydride-bridged and nonbridged rhodium phthalocyanine dimers. The reaction of the mu-hydrido complex (RPcH)Rh(mu-H)Rh(RPc) (5) (RPcH = RPc with one of its meso nitrogens protonated) with PMe3 at -10 degrees C produces (RPc)(PMe3)RhH (6), which further reacts with PMe3 to produce 4 and H-2 at higher temperatures. If the solution of 6 is allowed to warm in the absence of free PMe3, H-2 is also liberated and 6 is converted to an equal number of moles of 4 and [(RPc)Rh](2)(PMe3) (7). In contrast, the reaction of 5 with pyridine (py) produces (RPc)(py)RhH (11), which does not react with additional pyridine. Alternatively, 4 is generated by the reaction of the Rh-Rh bonded dimer [(RPc)Rh](2) (1) with PMe3. In this reaction, the formation of 7 as an intermediate may be shown by the titration of 1 with PMe3. Complex 1 reacts with 4 to produce (RPc)Rh- (10) and (RPc)(PMe3)(2-)Rh+ (9). A redox exchange between 4 and 9 ensues. The cobalt analogue of 4, i.e., (RPc)(PMe3)(2)Co (12), was generated reversibly by the reaction of (RPc)Co (13) with PMe3 at low temperatures. The LH NMR and the ESR spectra of 4, 12, and 13 indicate that while 13 is a metal-centered radical, 4 and 12 are best described as ligand-centered radicals. Therefore, 4 and 12 are formulated as Rh(III) and Co(III) complexes of the singly reduced pi-radical anion RPc.-, generated by metal-to-ligand charge-transfer reactions induced by phosphines. Consistent with formulation of 4 as a Rh(III) complex, it is only slowly oxidized in air and its PMe3 ligand is slow to exchange with the free phosphine. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Chen, MJ (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 19 TC 5 Z9 5 U1 1 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 NOV 2 PY 1998 VL 37 IS 22 BP 5786 EP 5792 DI 10.1021/ic980338i PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 136NB UT WOS:000076864600012 ER PT J AU Huang, BQ Corbett, JD AF Huang, BQ Corbett, JD TI Two new binary calcium-aluminum compounds: Ca13Al14, with a novel two-dimensional aluminum network, and Ca8Al3, an Fe3Al-type analogue SO INORGANIC CHEMISTRY LA English DT Article ID ZINTL-PHASES; HYDROGEN; METALS AB Ca13Al14 and Ca8Al3 are obtained by fusion of the appropriate mixture of the elements in Ta containers at 1100 degrees C followed by annealing at 600 degrees C or slow cooling, respectively. The structures of both compounds were determined by single-crystal X-ray means. Ca13Al14 crystallizes with monoclinic symmetry (space group C2/m (no. 12), Z = 2, a = 15.551(4) Angstrom, b = 9.873(2) Angstrom, c = 9.726(2) Angstrom, beta = 108.09(2)degrees), and Ca8Al3 has the triclinic Ca8In3-type structure (Pi (no. 2), Z = 2, a = 9.484(3) Angstrom, b = 9.592(3) Angstrom, c = 9.671(3) Angstrom, alpha = 99.02(3)degrees, beta = 101.13(3)degrees gamma = 119.55(3)degrees). Ca13Al14 contains a two-dimensional Al network structure composed of planar hexagonal six-membered rings, planar rhombus (four-membered) rings, and trigonal three-membered rings. An electron count on the basis of the simple Zintl-Klemm formalism for three- and four-bonded Al in Ca13Al14 suggests the phase is closed shell. However, full band-structure calculations within the extended Huckel formalism indicate that it is metallic, with considerable Ca-Al covalency and, characterically, with all AI-AI bonding states just filled at EF The descriptor "metallic Zintl phase" is apt. Ca8Al3 contains isolated Ca and Al atoms and is slightly electron-rich relative to classical valence rules. Both compounds are good metallic conductors with Pauli-paramagnetic-like properties. C1 Iowa State Univ Sci & Technol, Ames Lab, DOE, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ Sci & Technol, Ames Lab, DOE, Ames, IA 50011 USA. NR 26 TC 32 Z9 32 U1 0 U2 1 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 NOV 2 PY 1998 VL 37 IS 22 BP 5827 EP 5833 DI 10.1021/ic980656h PG 7 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 136NB UT WOS:000076864600019 ER PT J AU Huang, DP Dong, ZC Corbett, JD AF Huang, DP Dong, ZC Corbett, JD TI Na12K38Tl48Au2: A metallic zintl phase with naked icosahedral fragments Tl-7(7-) and Tl-9(9-) plus Au- SO INORGANIC CHEMISTRY LA English DT Article ID CLUSTER; COMPOUND; ANIONS; CHEMISTRY; THALLIUM; STATES; WORK AB The title compound is synthesized by direct reaction of the elements at 500 degrees C followed by slow cooling. Na12K38Tl48Au2 crystallizes hexagonal [space group (No. 189), Z = 1, a = 19.343(2) Angstrom, c = 11.498(5) Angstrom] and is constituted tin terms of oxidation states) as (Na+)(12)(K+)(38)(Tl-7(7-))(3)(Tl-9(9-))(3)(AU(-))(2) Both clusters have C-2 upsilon symmetry and can be viewed as fragments of a centered icosahedral Tl-13. The Tl-7(7-) cluster is an oblate pentagonal bipyramid with an apex-apex bond distance of 3.39 Angstrom, and Tl-9(9-) can be best derived from the centered icosahedron by removal of four adjoining vertexes (or as two fused pentagonal bipyramids). The isolated Au- is bound in a trigonal antiprism of potassium. The compound is structurally electron-precise (Zintl phase), but it shows characteristics of a very poor metal (rho(298) similar to 760 mu Omega(cm) with a Pauli-like susceptibility of similar to 1.4 x 10(-3) emu.mol(-1) over 50-300 K after correction for Larmor precession of cluster orbitals. EHMO results for the bonding in Tl-7(7-) and factors that stabilize this compound are presented and discussed. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Corbett, JD (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 28 TC 24 Z9 24 U1 0 U2 2 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 NOV 2 PY 1998 VL 37 IS 22 BP 5881 EP 5886 PG 6 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 136NB UT WOS:000076864600027 ER PT J AU Hay, BP Clement, O Sandrone, G Dixon, DA AF Hay, BP Clement, O Sandrone, G Dixon, DA TI A molecular mechanics (MM3(96)) force field for metal-amide complexes SO INORGANIC CHEMISTRY LA English DT Article ID NITRIC-ACID SOLUTIONS; SOLVENT-EXTRACTION; CHEMICAL SEPARATIONS; STRUCTURAL CRITERIA; SELECTIVE LIGANDS; RATIONAL DESIGN; ION; URANIUM(VI); PLUTONIUM(IV); STABILITY AB A molecular mechanics (MM3(96)) force field is reported for modeling metal complexes of amides in which the amide is coordinated through oxygen. This model uses a ''points-on-a-sphere'' approach which involves the parametrization of the M-O stretch, the M-O=C bend, and the M-O=C-X (X = C, H, N) torsion interactions. Relationships between force field parameters and metal ion properties (charge, ionic radius, and electronegativity) are presented that allow the application of this model to a wide range of metal ions. The model satisfactorily reproduces the structures of over fifty amide complexes with the alkaline earths, transition metals, lanthanides, and actinides. C1 Pacific NW Lab, Environm Mol Sci Lab, Theory Modeling & Simulat Grp, Richland, WA 99352 USA. RP Hay, BP (reprint author), Pacific NW Lab, Environm Mol Sci Lab, Theory Modeling & Simulat Grp, POB 999, Richland, WA 99352 USA. NR 61 TC 36 Z9 39 U1 1 U2 13 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 NOV 2 PY 1998 VL 37 IS 22 BP 5887 EP 5894 DI 10.1021/ic980641j PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA 136NB UT WOS:000076864600028 ER PT J AU Velkovsky, M AF Velkovsky, M TI Mean field, instantons and finite baryon density SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT Workshop QCD at Finite Baryon Density CY APR 27-30, 1998 CL UNIV BIELEFELD, CTR INTERDISCIPLINARY RES, BIELEFELD, GERMANY SP TMR Network, Commiss European Communities, Westfalisch Lipp Univ Gesell HO UNIV BIELEFELD, CTR INTERDISCIPLINARY RES ID QCD AB Instantons create a non-local interaction between the quarks, which at finite baryon density leads to the formation of a scalar diquark condensate and color superconductivity. A mean field approach leads to a self-consistent description of the [(q) over bar q] and [qq] condensates and shows the inevitability of a BCS type instability at the Fermi surface. The role of the rearrangement of the instanton ensemble for the QCD phase transitions is also discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Brookhaven Natl Lab, POB 5000, Upton, NY 11973 USA. EM momchil@bnl.gov NR 19 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD NOV 2 PY 1998 VL 642 IS 1-2 BP 58C EP 64C DI 10.1016/S0375-9474(98)00499-0 PG 7 WC Physics, Nuclear SC Physics GA 140RR UT WOS:000077102600008 ER PT J AU Weber, H Ernst, C Bass, SA Spieles, C Bleicher, P Belkacem, M Bravina, L Stocker, H Greiner, W AF Weber, H Ernst, C Bass, SA Spieles, C Bleicher, P Belkacem, M Bravina, L Stocker, H Greiner, W TI Excitation function of energy density and partonic degrees of freedom in relativistic heavy ion collisions SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT Workshop QCD at Finite Baryon Density CY APR 27-30, 1998 CL UNIV BIELEFELD, CTR INTERDISCIPLINARY RES, BIELEFELD, GERMANY SP TMR Network, Commiss European Communities, Westfalisch Lipp Univ Gesell HO UNIV BIELEFELD, CTR INTERDISCIPLINARY RES ID NUCLEUS-NUCLEUS COLLISIONS; QUARK-GLUON PLASMA; SUPERDENSE MATTER; EQUATION; STATE; DYNAMICS; QCD; CASCADES AB We estimate the energy density epsilon pile-up at mid-rapidity in central Pb+Pb collisions from 1 - 200 GeV/nucleon. epsilon is decomposed into hadronic and partonic contributions. A detailed analysis of the collision dynamics in the framework of a microscopic transport model shows the importance of partonic degrees of freedom and rescattering of leading (di)quarks in the early phase of the reaction for E-lab greater than or equal to 30 GeV/nucleon. The energy density reaches up to 4 GeV/fm(3), 95% of which are contained in partonic degrees of freedom. It is shown that cells of hadronic matter, after t approximate to 2R/gamma, can be viewed as nearly chemically equilibrated. This matter never exceeds energy densities of similar to 1 GeV/fm(-3), i.e. a density above which the notion of separated hadrons loses its meaning. C1 Univ Frankfurt, Inst Theoret Phys, D-60054 Frankfurt, Germany. Duke Univ, Dept Phys, Durham, NC 27708 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Weber, H (reprint author), Univ Frankfurt, Inst Theoret Phys, Robert Mayer Str 8-10, D-60054 Frankfurt, Germany. RI Stoecker, Horst/D-6173-2013 OI Stoecker, Horst/0000-0002-3282-3664 NR 28 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD NOV 2 PY 1998 VL 642 IS 1-2 BP 121C EP 129C DI 10.1016/S0375-9474(98)00507-7 PG 9 WC Physics, Nuclear SC Physics GA 140RR UT WOS:000077102600016 ER PT J AU Blaschke, D Roberts, CD AF Blaschke, D Roberts, CD TI Deconfinement and hadron properties at extremes of temperature and density SO NUCLEAR PHYSICS A LA English DT Article; Proceedings Paper CT Workshop QCD at Finite Baryon Density CY APR 27-30, 1998 CL UNIV BIELEFELD, CTR INTERDISCIPLINARY RES, BIELEFELD, GERMANY SP TMR Network, Commiss European Communities, Westfalisch Lipp Univ Gesell HO UNIV BIELEFELD, CTR INTERDISCIPLINARY RES ID CONFINEMENT; MESONS AB After introducing essential, qualitative concepts and results, we discuss the application of Dyson-Schwinger equations to QCD at finite T and mu. We summarise the calculation of the critical exponents of two-light-flavour QCD using the chiral and thermal susceptibilities; and an algebraic model that elucidates the origin of an anticorrelation between the mu- and T-dependence of a range of meson properties. That model also provides an algebraic understanding of why the finite-T behaviour of bulk thermodynamic properties is mirrored in their mu-dependence, and why meson masses decrease with mu even though f(pi) and -[(q) over bar q] increase. The possibility of diquark condensation is canvassed. Its realisation is uncertain because it is contingent upon an assumption about the quark-quark scattering kernel that is demonstrably false in some applications; e.g., it predicts the existence of coloured diquarks in the strong interaction spectrum, which are not observed. C1 Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. RP Blaschke, D (reprint author), Univ Rostock, Fachbereich Phys, D-18051 Rostock, Germany. NR 24 TC 21 Z9 21 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 NOV 2 PY 1998 VL 642 IS 1-2 BP 197C EP 209C DI 10.1016/S0375-9474(98)00517-X PG 13 WC Physics, Nuclear SC Physics GA 140RR UT WOS:000077102600026 ER PT J AU Oz, Y Terning, J AF Oz, Y Terning, J TI Orbifolds of AdS(5)xS(5) and 4d conformal field theories SO NUCLEAR PHYSICS B LA English DT Article DE anti-de Sitter; orbifolds; string theory ID ABSORPTION; 3-BRANES; BRANES AB We study the relation between the large N limit of four-dimensional N = 2, 1, 0 conformal field theories and supergravity on orbifolds of AdS(5) x S-5 We analyze the Kaluza-Klein states of the supergravity theory and relate them to the spectrum of (chiral) primary operators of the (super) conformal field theories. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Oz, Y (reprint author), Univ Calif Berkeley, Dept Phys, 366 LeConte Hall, Berkeley, CA 94720 USA. NR 60 TC 44 Z9 44 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 NOV 2 PY 1998 VL 532 IS 1-2 BP 163 EP 180 DI 10.1016/S0550-3213(98)00454-4 PG 18 WC Physics, Particles & Fields SC Physics GA 137GG UT WOS:000076905900009 ER PT J AU Csaki, C Murayama, H AF Csaki, C Murayama, H TI Instantons in partially broken gauge groups SO NUCLEAR PHYSICS B LA English DT Article DE instantons ID DYNAMICAL SUPERSYMMETRY BREAKING; YANG-MILLS THEORY; QUANTUM MODULI SPACE; SYMMETRY-BREAKING; EXACT SUPERPOTENTIALS; VACUUM-STRUCTURE; COULOMB PHASE; DUALITY; QCD; CONFINEMENT AB We discuss the effects of instantons in partially broken gauge groups on the low-energy effective gauge theory. Such effects arise when some of the instantons of the original gauge group G are no longer contained in (or can not be gauge rotated into) the unbroken group H, In cases of simple G and H, a good indicator for the existence of such instantons is the "index of embedding." However, in the general case one has to examine pi(3)(G/H) to decide whether there are any instantons in the broken part of the gauge group. We give several examples of supersymmetric theories where such instantons exist and leave their effects on the low-energy effective theory, (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RP Csaki, C (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 55 TC 18 Z9 18 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 NOV 2 PY 1998 VL 532 IS 1-2 BP 498 EP 526 DI 10.1016/S0550-3213(98)00448-9 PG 29 WC Physics, Particles & Fields SC Physics GA 137GG UT WOS:000076905900022 ER PT J AU 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 Schwarthoff, H Spencer, MB Sung, M Undrus, A Wolf, A Zoeller, MM Richichi, SJ Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menson, 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 Jaffe, DE Masek, G Paar, HP Potter, EM 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 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 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 Sahu, SK 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 AF 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 Schwarthoff, H Spencer, MB Sung, M Undrus, A Wolf, A Zoeller, MM Richichi, SJ Severini, H Skubic, P Bishai, M Fast, J Hinson, JW Menson, 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 Jaffe, DE Masek, G Paar, HP Potter, EM 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 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 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 Sahu, SK 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 CA CLEO Collaboration TI First search for CP violation in tau lepton decay SO PHYSICAL REVIEW LETTERS LA English DT Article ID MONTE-CARLO; LIBRARY AB We have performed the first search for CP violation in tau lepton decay. CP violation in lepton decay does not occur in the minimal standard model but can occur in extensions such as the multi-Higgs doublet model. It appears as a characteristic difference between the tau(-) and tau(+) decay angular distributions for the semileptonic decay modes such as tau(-) --> K-0 pi(-) nu. We define an observable asymmetry to exploit this and find no evidence for any CP violation. [S0031-9007(98)07548-6]. C1 Univ Minnesota, Minneapolis, MN 55455 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. 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 Florida, Gainesville, FL 32611 USA. Harvard Univ, Cambridge, MA 02138 USA. Univ Hawaii Manoa, Honolulu, HI 96822 USA. Univ Illinois, Urbana, IL 61801 USA. Carleton Univ, Ottawa, ON K1S 5B6, Canada. Inst Particle Phys, Montreal, PQ, Canada. McGill Univ, Montreal, PQ H3A 2T8, Canada. Ithaca Coll, Ithaca, NY 14850 USA. Univ Kansas, Lawrence, KS 66045 USA. RP Anderson, S (reprint author), Univ Minnesota, Minneapolis, MN 55455 USA. RI Briere, Roy/N-7819-2014; OI Briere, Roy/0000-0001-5229-1039; Bean, Alice/0000-0001-5967-8674; Poling, Ronald/0000-0001-7305-4702 NR 15 TC 9 Z9 9 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 NOV 2 PY 1998 VL 81 IS 18 BP 3823 EP 3827 DI 10.1103/PhysRevLett.81.3823 PG 5 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500005 ER PT J AU Deissler, RJ Brand, HR AF Deissler, RJ Brand, HR TI Effect of nonlinear gradient terms on breathing localized solutions in the quintic complex Ginzburg-Landau equation SO PHYSICAL REVIEW LETTERS LA English DT Article ID WEAKLY INVERTED BIFURCATION; BROKEN ROTATIONAL SYMMETRY; BINARY-FLUID CONVECTION; SUBCRITICAL BIFURCATIONS; SYSTEMS; STATES AB We study the effect of nonlinear gradient terms on breathing localized solutions in the complex Ginzburg-Landau equation. It is found that even small nonlinear gradient terms-which appear at the same order as the quintic term-can cause dramatic changes in the behavior of the solution, such as causing opposite sides of an otherwise monoperiodic symmetrically breathing solution to breathe at different frequencies, thus causing the solution to breathe periodically or chaotically on only one side or the solution to rapidly spread. [S0031-9007(98)07488-2]. C1 Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, Los Alamos, NM 87545 USA. Innovat Technol, Fairview Pk, OH 44126 USA. Univ Bayreuth, D-95440 Bayreuth, Germany. RP Deissler, RJ (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Nonlinear Studies, MS-B 258, Los Alamos, NM 87545 USA. NR 20 TC 45 Z9 49 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 NOV 2 PY 1998 VL 81 IS 18 BP 3856 EP 3859 DI 10.1103/PhysRevLett.81.3856 PG 4 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500013 ER PT J AU Colby, RH Zheng, X Rafailovich, MH Sokolov, J Peiffer, DG Schwarz, SA Strzhemechny, Y Nguyen, D AF Colby, RH Zheng, X Rafailovich, MH Sokolov, J Peiffer, DG Schwarz, SA Strzhemechny, Y Nguyen, D TI Dynamics of lightly sulfonated polystyrene ionomers SO PHYSICAL REVIEW LETTERS LA English DT Article ID BEHAVIOR; CHAINS AB The tracer diffusion coefficients of both ion-containing polymer chains and their associated counterions were measured in lightly sulfonated ionomers as a function of temperature, ion content, and chain length. The data are shown to be in good agreement with relaxation times derived from viscoelastic measurements at high temperatures. The results are interpreted in terms of a reptation model, modified to account for the additional constraints on individual chain motion imposed by the associating ion pairs. [S0031-9007(98)07469-9]. C1 Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. SUNY Stony Brook, Dept Mat Sci & Engn, Stony Brook, NY 11794 USA. ExxonMobil Res & Engn Co, Annandale, NJ 08801 USA. CUNY Queens Coll, Dept Phys, Flushing, NY 11367 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. NR 15 TC 45 Z9 45 U1 1 U2 19 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 NOV 2 PY 1998 VL 81 IS 18 BP 3876 EP 3879 DI 10.1103/PhysRevLett.81.3876 PG 4 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500018 ER PT J AU Krusin-Elbaum, L Blatter, G Thompson, JR Petrov, DK Wheeler, R Ullmann, J Chu, CW AF Krusin-Elbaum, L Blatter, G Thompson, JR Petrov, DK Wheeler, R Ullmann, J Chu, CW TI Anisotropic rescaling of a splayed pinning landscape in Hg cuprates: Strong vortex pinning and recovery of variable range hopping SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; COLUMNAR DEFECTS; SINGLE-CRYSTALS; FISSION; CONFIGURATIONS; ENTANGLEMENT; LOCALIZATION; VORTICES; ANGLES; LIQUID AB Strong vortex pinning by fission-induced uniformly splayed columnar tracks in anisotropic mercury cuprates is demonstrated to result from (re)scaling of the pinning landscape by a large superconducting anisotropy. The effective "narrowing" of the splay distribution restores variable range vortex hopping (VRH) motion expected for nearly parallel pins. VRH emerges as a distinctive peak in the vortex creep rate (similar to 12% at low fields at T/T-c similar to 0.5) of the most anisotropic HgBa2Ca2Cu3O8+delta, a peak well described by a glassy dynamics with the characteristic exponent mu similar to 1/3. [S0031-9007(98)07526-7]. C1 IBM Res Corp, Yorktown Heights, NY 10598 USA. ETH Honggerberg, CH-8093 Zurich, Switzerland. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Universal Energy Syst Inc, Dayton, OH 45432 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Houston, Texas Ctr Supercond, Houston, TX 77204 USA. RP Krusin-Elbaum, L (reprint author), IBM Res Corp, Yorktown Heights, NY 10598 USA. NR 21 TC 29 Z9 29 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 2 PY 1998 VL 81 IS 18 BP 3948 EP 3951 DI 10.1103/PhysRevLett.81.3948 PG 4 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500036 ER PT J AU Kopnin, NB Vinokur, VM AF Kopnin, NB Vinokur, VM TI Dynamic vortex mass in clean Fermi superfluids and superconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID D-WAVE SUPERCONDUCTORS; INERTIAL MASS; SPECTRAL FLOW; MUTUAL FRICTION; FLUX-FLOW; TEMPERATURE; MAGNUS; FIELD; FORCE; CORE AB We calculate the dynamic vortex mass for clean Fermi superfluids including both s- and d-wave superconductors as a response to a vortex acceleration. Assuming a finite quasiparticle mean free time, the vortex mass appears to be a tensor with components depending on the quasiparticle relaxation time. The diagonal component dominates in the limit of long mean free time while the off-diagonal mass takes over in the moderately clean regime. [S0031-9007(98)07543-7]. C1 LD Landau Theoret Phys Inst, Moscow 117940, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP LD Landau Theoret Phys Inst, Kosygina 2, Moscow 117940, Russia. NR 26 TC 26 Z9 26 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 2 PY 1998 VL 81 IS 18 BP 3952 EP 3955 DI 10.1103/PhysRevLett.81.3952 PG 4 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500037 ER PT J AU Booth, CH MacLaughlin, DE Heffner, RH Chau, R Maple, MB Kwei, GH AF Booth, CH MacLaughlin, DE Heffner, RH Chau, R Maple, MB Kwei, GH TI Pd/Cu site interchange and non-Fermi-liquid behavior in UCu4Pd SO PHYSICAL REVIEW LETTERS LA English DT Article ID MAGNETIC-SUSCEPTIBILITY; ELECTRONIC-STRUCTURE; KONDO DISORDER; HEAT; NMR AB X-ray-absorption fine-structure measurements of the local structure in UCu4Pd are described which indicate a probable lattice-disorder origin for non-Fermi-liquid behavior in this material. Short Pd-Cu distances are observed, consistent with (24 +/- 3)% of the Pd atoms occupying nominally Cu sites. A "Kondo disorder" model, based on the effect on the local Kondo temperature T-K of this interchange and some additional bond-length disorder, agrees quantitatively with previous experimental susceptibility data, and therefore also with specific heat and magnetic resonance experiments. [S0031-9007(98)07530-9]. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Riverside, Dept Phys, Riverside, CA 92521 USA. Univ Calif San Diego, Dept Phys, La Jolla, CA 92093 USA. RP Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RI Booth, Corwin/A-7877-2008 NR 13 TC 50 Z9 50 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 2 PY 1998 VL 81 IS 18 BP 3960 EP 3963 DI 10.1103/PhysRevLett.81.3960 PG 4 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500039 ER PT J AU Osborn, R Rosenkranz, S Argyriou, DN Vasiliu-Doloc, L Lynn, JW Sinha, SK Mitchell, JF Gray, KE Bader, SD AF Osborn, R Rosenkranz, S Argyriou, DN Vasiliu-Doloc, L Lynn, JW Sinha, SK Mitchell, JF Gray, KE Bader, SD TI Neutron scattering investigation of magnetic bilayer correlations in La1.2Sr1.8Mn2O7: Evidence of canting above T-C SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLOSSAL-MAGNETORESISTANCE; GIANT MAGNETORESISTANCE; MANGANITES; LAMNO3; STATE; ORDER AB Neutron scattering investigations of the paramagnetic correlations in the layered manganite La-1.2-Sr1.8Mn2O7, which exhibits colossal magnetoresistance above the Curie transition at T-C = 112 K, show that spins in neighboring layers within each bilayer are strongly canted at an average angle that is dependent on both the magnetic field and the temperature, as predicted by de Gennes. The inplane correlation length does not diverge at T-C, although the magnetic Bragg intensity obeys critical scaling below T-C, with the same temperature dependence as the zero-field electrical conductance. [S0031-9007(98)07520-6]. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. Natl Inst Stand & Technol, Ctr Neutron Res, Gaithersburg, MD 20899 USA. Univ Maryland, College Pk, MD 20742 USA. RP Osborn, R (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Osborn, Raymond/E-8676-2011; Rosenkranz, Stephan/E-4672-2011; Bader, Samuel/A-2995-2013 OI Osborn, Raymond/0000-0001-9565-3140; Rosenkranz, Stephan/0000-0002-5659-0383; NR 19 TC 97 Z9 97 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD NOV 2 PY 1998 VL 81 IS 18 BP 3964 EP 3967 DI 10.1103/PhysRevLett.81.3964 PG 4 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500040 ER PT J AU Phair, L Beaulieu, L Moretto, LG Wozniak, GJ AF Phair, L Beaulieu, L Moretto, LG Wozniak, GJ TI Evidence for dynamical fragment production? SO PHYSICAL REVIEW LETTERS LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Phair, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Beaulieu, Luc/A-6803-2009 OI Beaulieu, Luc/0000-0003-0429-6366 NR 4 TC 1 Z9 1 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 NOV 2 PY 1998 VL 81 IS 18 BP 4021 EP 4021 DI 10.1103/PhysRevLett.81.4021 PG 1 WC Physics, Multidisciplinary SC Physics GA 135YB UT WOS:000076829500055 ER PT J AU Taylor, DJ Fleig, PF Hietala, SL AF Taylor, DJ Fleig, PF Hietala, SL TI Technique for characterization of thin film porosity SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 25th International Conference on Metallurgical Coatings and Thin Films CY APR 25-MAY 01, 1998 CL SAN DIEGO, CALIFORNIA SP Vacuum Met, Thin Film Div, AVS DE thin film porosity; characterization; surface acoustic wave ID GEL AB Properties of thin films change with, and as a result of, porosity. It is important to know and understand these effects; however, it is difficult to measure them. In this work, several films with differing amounts of porosity were deposited by sol-gel methods onto quartz substrates and analyzed using a combined SAW/BET technique and ellipsometry. Gas adsorption was measured by a surface acoustic wave (SAW) device, and porosity was calculated using BET equations. Porosity data was compared and correlated with measurements made by ellipsometry (film refractive index and thickness) and SEM (surface topography). As these techniques do not yield pore size distribution, they are complimentary to the SAW technique, which directly measures porosity information. (C) 1998 Elsevier Science S.A. All rights reserved. C1 TPL Inc, Albuquerque, NM 87109 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Taylor, DJ (reprint author), TPL Inc, 3921 Acad Pkwy N, Albuquerque, NM 87109 USA. NR 6 TC 42 Z9 43 U1 1 U2 3 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 NOV 2 PY 1998 VL 332 IS 1-2 BP 257 EP 261 DI 10.1016/S0040-6090(98)01264-4 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 142LT UT WOS:000077202500047 ER PT J AU Jankowski, AF AF Jankowski, AF TI Characterizing and modeling the apparent anomalous behavior of resistivity in Cr-Si-O thin films SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 25th International Conference on Metallurgical Coatings and Thin Films CY APR 25-MAY 01, 1998 CL SAN DIEGO, CALIFORNIA SP Vacuum Met, Thin Film Div, AVS DE Cr-Si-O cermet; resistivity; effective medium theory; reactive sputtering ID PARTICLES AB The Cr-Si-O material system is of interest for use in thin film resistors. The films are sputter deposited onto conducting substrates from metal-oxide compacts using various reactive gas mixtures. The cermet film compositions range from 50 to 100 vol.% SiO2 as determined from elemental measurements of the Cr, Si and O content. In a wide range of resistivities from 10 to 10(14) Ohm-cm measured through the film thickness, an apparent anomalous behavior is found as a function of the Cr, Si and O composition. The anomaly can be attributed to a discontinuous variation of resistivity with film composition near 80 vol.% SiO2. The film microstructure is characterized as a distribution of conducting metal-silicide particles within an insulating matrix. The 'effective medium' theory is used to predict the variation of conductivity and successfully models the anomalous resistivity behavior. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Jankowski, AF (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 15 TC 11 Z9 11 U1 0 U2 1 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 NOV 2 PY 1998 VL 332 IS 1-2 BP 272 EP 276 DI 10.1016/S0040-6090(98)01098-0 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 142LT UT WOS:000077202500050 ER PT J AU Suryanarayana, C Ivanov, E Noufi, R Contreras, MA Moore, JJ AF Suryanarayana, C Ivanov, E Noufi, R Contreras, MA Moore, JJ TI Synthesis and processing of a Cu-In-Ga-Se sputtering target SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 25th International Conference on Metallurgical Coatings and Thin Films CY APR 25-MAY 01, 1998 CL SAN DIEGO, CALIFORNIA SP Vacuum Met, Thin Film Div, AVS DE sputtering target; mechanical alloying; X-ray diffraction; electron microscopy ID PHASE; CHALCOGENIDES; METALS; COPPER AB Formation of a homogeneous nanocrystalline CuIn0.7Ga0.3Se2 alloy was achieved by mechanical alloying of blended elemental Cu, In, Ga, and Se powders in a planetary ball mill. X-ray diffraction and transmission electron microscopy techniques were employed to follow the alloy formation during the milling process. It was observed that, depending upon the milling conditions, either a metastable cubic or a stable tetragonal phase was produced. The grain size of the mechanically alloyed powder was about 10 nm. The mechanically alloyed powder was consolidated to full density by hot isostatic pressing the powder at 750 degrees C and 100 MPa for 2 h. Irrespective of the nature of the phase in the starting powder, the hot isostatically pressed compact contained the well-recrystallized tetragonal CuIn0.7Ga0.3Se2 phase with a grain size of about 50 nm. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Colorado Sch Mines, Adv Coatings & Surface Engn Lab, Golden, CO 80401 USA. Tosoh SMD Inc, Grove City, OH 43213 USA. Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Suryanarayana, C (reprint author), Colorado Sch Mines, Adv Coatings & Surface Engn Lab, Golden, CO 80401 USA. RI Suryanarayana, C/B-9314-2008 NR 20 TC 11 Z9 14 U1 0 U2 2 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 NOV 2 PY 1998 VL 332 IS 1-2 BP 340 EP 344 DI 10.1016/S0040-6090(98)01033-5 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 142LT UT WOS:000077202500062 ER PT J AU Ruffner, JA Clem, PG Tuttle, BA Brinker, CJ Sriram, CS Bullington, JA AF Ruffner, JA Clem, PG Tuttle, BA Brinker, CJ Sriram, CS Bullington, JA TI Uncooled thin film infrared imaging device with aerogel thermal isolation: deposition and planarization techniques SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 25th International Conference on Metallurgical Coatings and Thin Films CY APR 25-MAY 01, 1998 CL SAN DIEGO, CALIFORNIA SP Vacuum Met, Thin Film Div, AVS DE aerogels; infrared imaging; pyroelectric; PZT; PLZT; planarization ID SILICA AB We have successfully integrated a thermally insulating silica aerogel thin film into a new uncooled monolithic thin film infrared (IR) imaging device. We have calculated noise equivalent temperature differences of 0.04-0.10 degrees C from a variety of PbxZryTi1-yO3 (PZT) and PbxL1-xZryTi1-yO3 (PLZT) pyroelectric imaging elements in these monolithic structures. The low thermal conductivity of the aerogel films should also result in a significantly faster temporal response as well. Fabrication of these monolithic devices entails sol-gel deposition of the aerogel, sputter deposition of the electrodes, and solution chemistry deposition of the pyroelectric element. Consistent pyroelectric response across the device is achieved by use of appropriate deposition and planarization techniques of these three layers. Adjusting the chemistry and deposition process of the aerogel thin film had the greatest effect on large-scale uniformity and performance across the device. Sputter depositing a planarization layer on top of the aerogel offered only minimal improvement in reducing surface roughness. However, using solution chemistry to deposit multiple thin coatings of PZT for the imaging element resulted in a visible reduction in scattering and 80-100% pixel yield. (C) 1998 Elsevier Science S.A. All rights reserved. C1 Sandia Natl Labs MS 1349, Albuquerque, NM 87185 USA. Univ New Mexico, Dept Chem & Nucl Engn, Albuquerque, NM 87131 USA. AMMPEC Inc, Albuquerque, NM 87109 USA. RP Ruffner, JA (reprint author), Sandia Natl Labs MS 1349, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 19 Z9 23 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 NOV 2 PY 1998 VL 332 IS 1-2 BP 356 EP 361 DI 10.1016/S0040-6090(98)01031-1 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA 142LT UT WOS:000077202500065 ER PT J AU Dyer, RB Gai, F Woodruff, WH AF Dyer, RB Gai, F Woodruff, WH TI Infrared studies of fast events in protein folding SO ACCOUNTS OF CHEMICAL RESEARCH LA English DT Review ID LASER TEMPERATURE-JUMP; GCN4 LEUCINE-ZIPPER; RELAXATION DYNAMICS; COILED COILS; SPECTROSCOPY; APOMYOGLOBIN; HELIX; INTERMEDIATE; PEPTIDE; NANOSECOND C1 Los Alamos Natl Lab, Chem Sci & Technol Div, Biosci & Biotechnol Grp CST 4, Los Alamos, NM 87545 USA. Albert Einstein Coll Med, Dept Biochem, Bronx, NY 10461 USA. RP Dyer, RB (reprint author), Los Alamos Natl Lab, Chem Sci & Technol Div, Biosci & Biotechnol Grp CST 4, Mail Stop J586, Los Alamos, NM 87545 USA. NR 53 TC 151 Z9 152 U1 1 U2 20 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0001-4842 J9 ACCOUNTS CHEM RES JI Accounts Chem. Res. PD NOV PY 1998 VL 31 IS 11 BP 709 EP 716 DI 10.1021/ar970343a PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA 144QN UT WOS:000077326400004 ER PT J AU Lamberty, A Savory, J Moody, JR De Bievre, P Rosman, KJR Gramlich, JW AF Lamberty, A Savory, J Moody, JR De Bievre, P Rosman, KJR Gramlich, JW TI The IRMM International Measurement Evaluation Programme (IMEP) IMEP-4: Trace elements (Li, Cu, Zn) in serum SO ACCREDITATION AND QUALITY ASSURANCE LA English DT Article DE International Measurement Evaluation Programme; isotope-specific methods; isotope dilution mass spectrometry; trace elements in serum; comparability and traceability of analytical measurements ID DILUTION MASS-SPECTROMETRY AB The aim of the International Measurement Evaluation Programme (IMEP) is to give an objective picture of state-of-the-practice analytical measurements by comparing them to a reference value obtained by a primary method of measurement. The reference-value is therefore as traceable to the SI system of measurements as can presently be achieved and is independent of human or political decisions. Thus a large scale field test is made to achieve (international) comparability of measurements by comparing them with an independent metrologically established value. In the fourth measurement round, IMEP-4, three trace elements, Li, Cu and Zn, at three different levels in (bovine) serum were measured by about 12 participating laboratories using their routine methods. The (coded) results are graphically reported and compared to certified reference values established by an isotope-specific method, isotope dilution mass spectrometry, defined as a primary method of measurement by the Consultative Committee on Amount of Substance. Results indicate a spread of more than +/- 50%, asymmetrically distributed around the reference value with its own uncertainty range, although the self-declared accuracy of the laboratories was 5-10%. Self-assessment by participants of their analytical capabilities does not show a high correlation between self-rating ("more experienced" or "less experienced") and actual performance. In the way they have been applied, all methods seem to produce results of approximately the same quality. C1 Commiss European Communities, Joint Res Ctr, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. Univ Virginia, Med Ctr, Dept Pathol & Biochem, Charlottesville, VA USA. US Natl Inst Stand & Technol, Gaithersburg, MD 20899 USA. Curtin Univ Technol, Perth, WA 6001, Australia. New Brunswick Lab, Argonne, IL USA. RP De Bievre, P (reprint author), Commiss European Communities, Joint Res Ctr, Inst Reference Mat & Measurements, B-2440 Geel, Belgium. NR 9 TC 9 Z9 9 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 USA SN 0949-1775 J9 ACCREDIT QUAL ASSUR JI Accredit. Qual. Assur. PD NOV PY 1998 VL 3 IS 11 BP 447 EP 458 DI 10.1007/s007690050284 PG 12 WC Chemistry, Analytical; Instruments & Instrumentation SC Chemistry; Instruments & Instrumentation GA 143JB UT WOS:000077250900004 ER PT J AU Hart, M Berman, L AF Hart, M Berman, L TI X-ray optics for synchrotron radiation; Perfect crystals, mirrors and multilayers SO ACTA CRYSTALLOGRAPHICA SECTION A LA English DT Article ID NUCLEAR BRAGG SCATTERING; ENERGY RESOLUTION; SYSTEMATIC METHOD; PHASE PLATE; MONOCHROMATORS; DIFFRACTION; PERFORMANCE; NEUTRONS; BACKSCATTERING; SILICON AB The X-ray optical properties of mirrors and Bragg reflecting perfect crystals are almost perfectly matched to the characteristics of synchrotron-radiation sources. That the X-ray refractive index is close to but less than one was realised early in the history of X-ray scattering - consequences are that mirrors exhibit total external reflection over a small angle range, ca 0.01 rad, and perfect crystals totally reflect X-rays in a small angle range. similar to a few seconds of are near the Bragg angle. The theory and application of these unique properties was developed in considerable derail in the three decades before the advent of the synchrotron-radiation era. This historical development is traced with special emphasis on the way in which the optical concepts were then straightforwardly applied to synchrotron-radiation X-ray optical design. In more recent times, the technology of synthetic multilayers has been developed so that these too are widely used in X-ray optics for synchrotron-radiation beamlines. As X-ray synchrotron-radiation sources were born, perfect-crystal X-ray optics and crystal-growth technology matured; this symbiosis was not planned, it could not have been planned ... but it works, spectacularly! C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Hart, M (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. EM mhart@bnl.gov NR 71 TC 19 Z9 19 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7673 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD NOV 1 PY 1998 VL 54 SI 1 BP 850 EP 858 DI 10.1107/S0108767398011283 PN 6 PG 9 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA 150XX UT WOS:000077692300018 ER PT J AU Sussman, JL Lin, DW Jiang, JS Manning, NO Prilusky, J Ritter, O Abola, EE AF Sussman, JL Lin, DW Jiang, JS Manning, NO Prilusky, J Ritter, O Abola, EE TI Protein Data Bank (PDB): Database of three-dimensional structural information of biological macromolecules SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article AB The Protein Data Bank (PDB) at Brookhaven National Laboratory, is a database containing experimentally determined three-dimensional structures of proteins, nucleic acids and other biological macromolecules, with approximately 8000 entries. Data are easily submitted via PDB's WWW-based tool AutoDep, in either mmCIF or PDB format, and are most conveniently examined via PDB's WWW-based tool 3DB Browser. C1 Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. Weizmann Inst Sci, Bioinformat Unit, IL-76100 Rehovot, Israel. German Canc Res Ctr, Dept Mol Biophys, D-69120 Heidelberg, Germany. RP Sussman, JL (reprint author), Brookhaven Natl Lab, Dept Biol, Bldg 463, Upton, NY 11973 USA. OI Sussman, Joel/0000-0003-0306-3878 NR 13 TC 286 Z9 292 U1 3 U2 13 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD NOV 1 PY 1998 VL 54 SI S1 BP 1078 EP 1084 DI 10.1107/S0907444998009378 PN 6 PG 7 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 147MT UT WOS:000077511400004 PM 10089483 ER PT J AU Ravelli, RBG Raves, ML Ren, Z Bourgeois, D Roth, M Kroon, J Silman, I Sussman, JL AF Ravelli, RBG Raves, ML Ren, Z Bourgeois, D Roth, M Kroon, J Silman, I Sussman, JL TI Static Laue diffraction studies on acetylcholinesterase SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID MOLECULAR-DYNAMICS SIMULATION; TIME-RESOLVED CRYSTALLOGRAPHY; ACTIVE-SITE GORGE; BACK-DOOR; CRYSTAL-STRUCTURE; LIGAND-BINDING; COMPLEX; PROTEIN; FASCICULIN; CHOLINESTERASES AB Acetylcholinesterase (AChE) is one of nature's fastest enzymes, despite the fact that its three-dimensional structure reveals its active site to be deeply sequestered within the molecule. This raises questions with respect to traffic of substrate to, and products from, the active site, which may be investigated by time-resolved crystallography. In order to address one aspect of the feasibility of performing time-resolved studies on AChE, a data set has been collected using the Laue technique on a trigonal crystal of Torpedo californica AChE soaked with the reversible inhibitor edrophonium, using a total X-ray exposure time of 24 ms. Electron-density maps obtained from the Laue data, which are of surprisingly good quality compared with similar maps from monochromatic data, show essentially the same features. They clearly reveal the bound ligand, as well as a structural change in the conformation of the active-site Ser200 induced upon binding. C1 Univ Utrecht, Bijvoet Ctr Biomol Res, Dept Crystal & Struct Chem, NL-3584 CH Utrecht, Netherlands. Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. Univ Chicago, Dept Biochem & Mol Biol, Chicago, IL 60637 USA. Inst Biol Struct Jean Pierre Ebel, F-38027 Grenoble 1, France. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Weizmann Inst Sci, Dept Neurobiol, IL-76100 Rehovot, Israel. RP Ravelli, RBG (reprint author), Univ Utrecht, Bijvoet Ctr Biomol Res, Dept Crystal & Struct Chem, Padualaan 8, NL-3584 CH Utrecht, Netherlands. OI Sussman, Joel/0000-0003-0306-3878 NR 40 TC 34 Z9 36 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD NOV 1 PY 1998 VL 54 SI S2 BP 1359 EP 1366 DI 10.1107/S0907444998005277 PN 6 PG 8 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA 144KT UT WOS:000077314300014 PM 10089512 ER PT J AU Oset, E Oller, JA Pelaez, JR Ramos, A AF Oset, E Oller, JA Pelaez, JR Ramos, A TI Meson-meson and meson-baryon interactions in a chiral non-perturbative approach SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT MESON'98 Conference on the Structure of Mesons, Baryons and Nuclei CY MAY 26-JUN 02, 1998 CL KRAKOW, POLAND SP Inst Phys, Jagellonian Univ Cracow, Forsch Zentrum, Gesell Schwerionen Forsch, IFJ Cracow, Polish State Comm Sci Res, Phys Comm Polish Acad Sci, Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung ID SCATTERING; DYNAMICS; CHANNELS AB A qualitative account of the meson-meson and meson-baryon interactions using chiral Lagrangians and the inverse amplitude method in coupled channels is done. The method, imposing exact unitarity, proves to be a very useful tool to extend the information contained in the chiral Lagrangians at energies beyond the realm of applicability of chiral perturbation theory. C1 Dept Fis Teor, Valencia 46100, Spain. IFIC, Ctr Mixto Univ Valencia CSIC, Valencia 46100, Spain. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Barcelona, Dept Estructura & Constituents Mat, E-08028 Barcelona, Spain. RP Oset, E (reprint author), Dept Fis Teor, Valencia 46100, Spain. RI Pelaez, Jose/K-9767-2014; Ramos, Angels/L-3043-2014 OI Pelaez, Jose/0000-0003-0737-4681; Ramos, Angels/0000-0002-0882-1570 NR 16 TC 3 Z9 3 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1998 VL 29 IS 11 BP 3101 EP 3109 PG 9 WC Physics, Multidisciplinary SC Physics GA 152TR UT WOS:000077793300024 ER PT J AU Gibson, BF AF Gibson, BF TI Baryon-baryon mixing in hypernuclei SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT MESON'98 Conference on the Structure of Mesons, Baryons and Nuclei CY MAY 26-JUN 02, 1998 CL KRAKOW, POLAND SP Inst Phys, Jagellonian Univ Cracow, Forsch Zentrum, Gesell Schwerionen Forsch, IFJ Cracow, Polish State Comm Sci Res, Phys Comm Polish Acad Sci, Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung ID OBSERVABLES AB Implications of few-body hypernuclei for our understanding of the baryon-baryon interaction are examined. Octet-octet coupling effects not present in conventional, non strange nuclei are the focus. The need to identify strangeness -2 hypernuclei to test model predictions is emphasized. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Gibson, BF (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1998 VL 29 IS 11 BP 3203 EP 3209 PG 7 WC Physics, Multidisciplinary SC Physics GA 152TR UT WOS:000077793300039 ER PT J AU Koch, V AF Koch, V TI Dilepton production in relativistic heavy ion collisions SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT MESON'98 Conference on the Structure of Mesons, Baryons and Nuclei CY MAY 26-JUN 02, 1998 CL KRAKOW, POLAND SP Inst Phys, Jagellonian Univ Cracow, Forsch Zentrum, Gesell Schwerionen Forsch, IFJ Cracow, Polish State Comm Sci Res, Phys Comm Polish Acad Sci, Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung ID LOW-MASS DILEPTONS; ELECTRON PAIRS; RHO-MESON; TEMPERATURE; ENHANCEMENT; MATTER; RATES; CERN AB In this contribution we will discuss the production of low mass dileptons. The current theoretical understanding will be briefly reviewed, emphasising possible in medium effects. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Koch, V (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1998 VL 29 IS 11 BP 3233 EP 3239 PG 7 WC Physics, Multidisciplinary SC Physics GA 152TR UT WOS:000077793300043 ER PT J AU Furget, C Abbott, D Ahmidouch, A Anklin, H Arvieux, J Ball, J Beedoe, S Beise, EJ Bimbot, L Boeglin, W Breuer, H Carlini, R Chant, NS Danagoulian, S Dow, K Ducret, JE Dunne, J Ewell, L Eyraud, L Garcon, M Gilman, R Glashausser, C Gueye, P Gustafsson, K Hafidi, K Honneger, A Jourdan, J Kox, S Kumbarski, G Lu, L Lung, A Mack, D Markowitz, P McIntyre, J Meekins, D Merchez, F Mitchell, J Mtingwa, S Mrktchyan, H Pitz, D Qin, L Ransome, R Real, JS Roos, PG Rutt, P Schmidt, W Sawafta, R Stepanyan, S Stephenson, EJ Tieulent, R Tomasi-Gustafsson, E Turchinetz, W Vansyoc, K Volmer, J Voutier, E Vulcan, W Williamson, C Wood, SA Yan, C Zhao, J Zhao, W AF Furget, C Abbott, D Ahmidouch, A Anklin, H Arvieux, J Ball, J Beedoe, S Beise, EJ Bimbot, L Boeglin, W Breuer, H Carlini, R Chant, NS Danagoulian, S Dow, K Ducret, JE Dunne, J Ewell, L Eyraud, L Garcon, M Gilman, R Glashausser, C Gueye, P Gustafsson, K Hafidi, K Honneger, A Jourdan, J Kox, S Kumbarski, G Lu, L Lung, A Mack, D Markowitz, P McIntyre, J Meekins, D Merchez, F Mitchell, J Mtingwa, S Mrktchyan, H Pitz, D Qin, L Ransome, R Real, JS Roos, PG Rutt, P Schmidt, W Sawafta, R Stepanyan, S Stephenson, EJ Tieulent, R Tomasi-Gustafsson, E Turchinetz, W Vansyoc, K Volmer, J Voutier, E Vulcan, W Williamson, C Wood, SA Yan, C Zhao, J Zhao, W TI Tensor polarization measurement in elastic electron-deuteron scattering at large momentum transfer SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT MESON'98 Conference on the Structure of Mesons, Baryons and Nuclei CY MAY 26-JUN 02, 1998 CL KRAKOW, POLAND SP Inst Phys, Jagellonian Univ Cracow, Forsch Zentrum, Gesell Schwerionen Forsch, IFJ Cracow, Polish State Comm Sci Res, Phys Comm Polish Acad Sci, Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung ID RANGE AB The three tensor polarization components (t(20), t(21) and t(22)) of the recoil deuteron in elastic electron-deuteron scattering have been measured in the range of 4-momentum transfer Q = 4.1-6.8 fm(-1). The experiment was performed with the multi-GeV, high intensity electron beam available at the Jefferson Laboratory and using the tensor deuteron polarimeter POLDER. These new data are used to separate the charge G(C) and quadrupole G(Q) form factors at large momentum transfer and provide additional constraints on theoretical models. C1 Inst Sci Nucl, Grenoble, France. CEA Saclay, Serv Phys Nucl, DAPNIA, Gif Sur Yvette, France. Univ Maryland, College Pk, MD 20742 USA. Jefferson Lab, Newport News, VA USA. MIT Bates, Cambridge, MA 02140 USA. Rutgers State Univ, New Brunswick, NJ 08903 USA. Univ Basel, Inst Phys, Basel, Switzerland. Natl Saturne Lab, Gif Sur Yvette, France. N Carolina Agr & Technol State Univ, Greensboro, NC 27411 USA. Florida Int Univ, Miami, FL 33199 USA. Inst Phys Nucl, F-91406 Orsay, France. Inst Phys, Yerevan, Armenia. Indiana Univ, Cyclotron Facil, Bloomington, IN USA. RP Furget, C (reprint author), Inst Sci Nucl, Grenoble, France. RI McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 13 TC 7 Z9 7 U1 0 U2 2 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1998 VL 29 IS 11 BP 3301 EP 3307 PG 7 WC Physics, Multidisciplinary SC Physics GA 152TR UT WOS:000077793300052 ER PT J AU Page, PR AF Page, PR TI Gluonic excitations in mesons SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT MESON'98 Conference on the Structure of Mesons, Baryons and Nuclei CY MAY 26-JUN 02, 1998 CL KRAKOW, POLAND SP Inst Phys, Jagellonian Univ Cracow, Forsch Zentrum, Gesell Schwerionen Forsch, IFJ Cracow, Polish State Comm Sci Res, Phys Comm Polish Acad Sci, Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung ID LATTICE AB We report on some interesting recent theoretical and experimental advances on J(PC) exotics and hybrid mesons. These are the decay selection rules governing JPC exotic decay, the experimental evidence for a J(PC) = 1(-+) exotic in eta pi and rho pi, and the production of charmonium hybrids at forthcoming B-factories. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Page, PR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,T-5,MS-B283, Los Alamos, NM 87545 USA. RI Page, Philip/L-1885-2015 OI Page, Philip/0000-0002-2201-6703 NR 23 TC 1 Z9 1 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1998 VL 29 IS 11 BP 3387 EP 3393 PG 7 WC Physics, Multidisciplinary SC Physics GA 152TR UT WOS:000077793300066 ER PT J AU Thielemann, FK Freiburghaus, C Rauscher, T Rembges, F Rosswog, S Pfeiffer, B Kratz, KL Schatz, H Wiescher, MC AF Thielemann, FK Freiburghaus, C Rauscher, T Rembges, F Rosswog, S Pfeiffer, B Kratz, KL Schatz, H Wiescher, MC TI Explosive nucleosynthesis close to the drip lines SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT MESON'98 Conference on the Structure of Mesons, Baryons and Nuclei CY MAY 26-JUN 02, 1998 CL KRAKOW, POLAND SP Inst Phys, Jagellonian Univ Cracow, Forsch Zentrum, Gesell Schwerionen Forsch, IFJ Cracow, Polish State Comm Sci Res, Phys Comm Polish Acad Sci, Wilhelm Heinrich Heraeus & Else Heraeus-Stiftung ID GAMMA-RAY BURSTS; NEUTRINO-DRIVEN WINDS; NUCLEAR-MASS FORMULA; R-PROCESS; QUASI-EQUILIBRIUM; STAR MATTER; MODELS; NOVAE; APPROXIMATION; DECOMPRESSION AB We give an overview of explosive burning and the role which neutron and/or proton separation energies play. We focus then on the rapid neutron capture process (r-process) which encounters unstable nuclei with neutron separation energies in the range 1-4 MeV, and the rapid proton capture process (rp-process), operating close to the proton drip-line. The site of the rp-process is related to hydrogen accreting neutron stars in binary stellar systems. Explosive II-burning produces nuclei as heavy as A=100, powering events observable as X-ray bursts. The r-process abundances witness nuclear structure far from beta-stability as well as the conditions in the appropriate astrophysical environment. But there is a remaining lack in the full understanding of its astrophysical origin, ranging from the high entropy neutrino wind, blown from hot neutron star surfaces after a supernova explosion, to low entropy "cold decompresssion" of neutron star matter ejected in mergers of binary neutron star systems. C1 Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland. Univ Mainz, Inst Kernchem, D-55099 Mainz, Germany. Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Notre Dame, Dept Phys, Notre Dame, IN 46556 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Thielemann, FK (reprint author), Univ Basel, Dept Phys & Astron, Klingelbergstr 82, CH-4056 Basel, Switzerland. RI Rauscher, Thomas/D-2086-2009 OI Rauscher, Thomas/0000-0002-1266-0642 NR 63 TC 1 Z9 1 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD NOV PY 1998 VL 29 IS 11 BP 3503 EP 3513 PG 11 WC Physics, Multidisciplinary SC Physics GA 152TR UT WOS:000077793300078 ER PT J AU Soderlind, P AF Soderlind, P TI Theory of the crystal structures of cerium and the light actinides SO ADVANCES IN PHYSICS LA English DT Review ID GENERALIZED GRADIENT APPROXIMATION; CUBIC TRANSITION-METALS; ALPHA-GAMMA TRANSITION; ELECTRONIC-STRUCTURE; PHASE-TRANSITIONS; ELASTIC-CONSTANTS; GAMMA->ALPHA TRANSITION; STRUCTURE STABILITIES; EXTREME COMPRESSIONS; THORIUM METAL AB First-principles theory, based on the density-functional approach, is used to study the crystal structures of Ce and the light actinides (Th-Pu) at low temperatures as a function of hydrostatic pressure. Calculated ground-state properties, such as crystal structure, atomic Volume and bulk modulus, are shown to be very well described within this theory. We present the following pressure induced phase transitions: Ce, fcc-->bct-->hcp; The fcc-->bct-->hcp; Pa, bct-->alpha-U-->bct-->hcp; U, alpha-U-->bct-->bcc; Np, alpha-Np-->beta-Np-->bcc; Pu, alpha-Pu-->alpha-Np -->beta-NP-->bcc. We explain the occurrence of low-symmetry (complex) structures in these metals as a consequence of a symmetry-breaking mechanism that shows similarities to a Peierls distortion. The ultimate high-pressure phases are well accounted for in a canonical model for the f bands for these metals. C1 Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 88 TC 118 Z9 119 U1 4 U2 20 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0001-8732 EI 1460-6976 J9 ADV PHYS JI Adv. Phys. PD NOV-DEC PY 1998 VL 47 IS 6 BP 959 EP 998 DI 10.1080/000187398243492 PG 40 WC Physics, Condensed Matter SC Physics GA 140KL UT WOS:000077086400002 ER PT J AU Hill, R Lewis, GK AF Hill, R Lewis, GK TI Directed light fabrication of aircraft components SO AEROSPACE ENGINEERING LA English DT Article C1 Boeing Commercial Airplane Grp, Seattle, WA USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Hill, R (reprint author), Boeing Commercial Airplane Grp, Seattle, WA USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC AUTOMOTIVE ENG INC PI WARRENDALE PA 400 COMMONWEALTH DRIVE, WARRENDALE, PA 15096 USA SN 0736-2536 J9 AEROSPACE ENG JI Aerosp. Eng. PD NOV PY 1998 VL 18 IS 11 BP 31 EP 33 PG 3 WC Engineering, Aerospace SC Engineering GA 140CX UT WOS:000077070100021 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Pappas, NR Wong, CT Pascani, K Felder, CA Hitzemann, RJ AF Wang, GJ Volkow, ND Fowler, JS Pappas, NR Wong, CT Pascani, K Felder, CA Hitzemann, RJ TI Regional cerebral metabolism in female alcoholics of moderate severity does not differ from that of controls SO ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH LA English DT Article DE alcoholism; cerebral glucose metabolism; gender; PET ID POSITRON EMISSION TOMOGRAPHY; GLUCOSE-UTILIZATION; FRONTAL HYPOMETABOLISM; BRAIN; WOMEN; MEN; CONSUMPTION; ESTRADIOL; RECOVERY; ETHANOL AB It is generally believed that women are more vulnerable to alcohol's toxic effects than men. Studies in male alcoholics have consistently shown reductions in brain glucose metabolism, However, such studies have not been done in female alcoholics, The purpose of this study was to evaluate if similar or worse brain metabolic abnormalities occurred in female alcoholics. For this purpose, we measured regional brain metabolism with positron emission tomography and [F-18]fluorodeoxyglucose In 10 recently detoxified female alcoholics and compared it with that in 12 age-matched female controls. There were no differences between alcoholics and control females in regional brain glucose metabolism whether we used regions of Interest analysis or statistical parameter maps methods. These results do not support a higher toxicity for the effects of alcohol in the female brain, as assessed with regional brain glucose metabolism, because metabolic values in female alcoholics did not differ from those of controls, whereas metabolic values in male alcoholics are generally lower than those in controls. However, this study is confounded by the fact that the seventy of alcohol use in these female alcoholics was less than that of the male alcoholics previously investigated In positron emission tomography studies. Future studies in male subjects with alcoholism of moderate severity are required to address gender differences in sensitivity to alcohol effects In brain metabolism. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. SUNY Stony Brook, Dept Radiol, Stony Brook, NY 11794 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. Vet Affairs Med Ctr, Psychiat Serv, Northport, NY USA. RP Wang, GJ (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. FU NIAAA NIH HHS [1RO1 AA09481-01]; NIDA NIH HHS [5RO1 DA/MH09971] NR 36 TC 14 Z9 14 U1 1 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 USA SN 0145-6008 J9 ALCOHOL CLIN EXP RES JI Alcoholism (NY) PD NOV PY 1998 VL 22 IS 8 BP 1850 EP 1854 DI 10.1097/00000374-199811000-00035 PG 5 WC Substance Abuse SC Substance Abuse GA 139WG UT WOS:000077053700036 PM 9835307 ER PT J AU Mears, AJ Jordan, T Mirzayans, F Dubois, S Kume, P Parlee, M Ritch, R Koop, B Kuo, WL Collins, C Marshall, J Gould, DB Pearce, W Carlsson, P Enerback, S Morissette, J Bhattacharya, S Hogan, B Raymond, V Walter, MA AF Mears, AJ Jordan, T Mirzayans, F Dubois, S Kume, P Parlee, M Ritch, R Koop, B Kuo, WL Collins, C Marshall, J Gould, DB Pearce, W Carlsson, P Enerback, S Morissette, J Bhattacharya, S Hogan, B Raymond, V Walter, MA TI Mutations of the forkhead/winged-helix gene, FKHL7, in patients with Axenfeld-Rieger anomaly SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID PRIMARY CONGENITAL GLAUCOMA; AUTOSOMAL-DOMINANT IRIDOGONIODYSGENESIS; OPEN-ANGLE GLAUCOMA; FORK HEAD DOMAIN; HUMAN PAX6 GENE; DNA-BINDING; ALVEOLAR RHABDOMYOSARCOMA; TRANSCRIPTION FACTORS; RING CHROMOSOME-6; FAMILY AB Genetic linkage, genome mismatch scanning, and analysis of patients with alterations of chromosome 6 have indicated that a major locus for development of the anterior segment of the eye, IRID1, is located at 6p25. Abnormalities of this locus lead to glaucoma. FKHL7 (also called "FREAC3"), a member of the forkhead/winged-helix transcription-factor family, has also been mapped to 6p25. DNA sequencing of FKHL7 in five IRID1 families and 16 sporadic patients with anterior-segment defects revealed three mutations: a 10-bp deletion predicted to cause a frameshift and premature protein truncation prior to the FKHL7 forkhead DNA-binding domain, as well as two missense mutations of conserved amino acids within the FKHL7 forkhead domain. Mf1, the murine homologue of FKHL7, is expressed in the developing brain, skeletal system, and eye, consistent with FKHL7 having a role in ocular development. However, mutational screening and genetic-linkage analyses excluded FKHL7 from underlying the anterior-segment disorders in two IRID1 families with linkage to 6p25. Our findings demonstrate that, although mutations of FKHIL7 result in anterior-segment defects and glaucoma in some patients, it is probable that at least one more locus involved in the regulation of eye development is also located at 6p25. C1 Univ Alberta, Dept Ophthalmol, Edmonton, AB, Canada. Univ Alberta, Dept Med Genet, Edmonton, AB, Canada. Inst Ophthalmol, Dept Mol Genet, London, ON, Canada. CHU Laval, Res Ctr, Mol Endocrinol Lab, Quebec City, PQ G1V 4G2, Canada. Univ Laval, Quebec City, PQ G1K 7P4, Canada. Vanderbilt Univ, Med Ctr, Howard Hughes Med Inst, Nashville, TN USA. Univ Victoria, Dept Biol, Ctr Environm Hlth, Victoria, BC V8W 2Y2, Canada. New York Eye & Ear Infirm, Dept Ophthalmol, New York, NY 10003 USA. Univ Calif San Francisco, Canc Genet Program, San Francisco, CA 94143 USA. Lawrence Berkeley Lab, Berkeley, CA USA. Univ Gothenburg, Dept Biol Mol, Gothenburg, Sweden. RP Walter, MA (reprint author), Univ Alberta, Ocular Genet Lab, 832 Med Sci Bldg, Edmonton, AB, Canada. RI Koop, Ben/A-8151-2008; Carlsson, Peter/B-5551-2008 OI Koop, Ben/0000-0003-0045-5200; Carlsson, Peter/0000-0001-6535-5927 NR 51 TC 205 Z9 211 U1 0 U2 8 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD NOV PY 1998 VL 63 IS 5 BP 1316 EP 1328 DI 10.1086/302109 PG 13 WC Genetics & Heredity SC Genetics & Heredity GA 138QZ UT WOS:000076985200008 PM 9792859 ER PT J AU Gustavsson, P Garelli, E Draptchinskaia, N Ball, S Willig, TN Tentler, D Dianzani, I Punnett, HH Shafer, FE Cario, H Ramenghi, U Glomstein, A Pfeiffer, RA Goringe, A Olivieri, NF Smibert, E Tchernia, G Elinder, G Dahl, N AF Gustavsson, P Garelli, E Draptchinskaia, N Ball, S Willig, TN Tentler, D Dianzani, I Punnett, HH Shafer, FE Cario, H Ramenghi, U Glomstein, A Pfeiffer, RA Goringe, A Olivieri, NF Smibert, E Tchernia, G Elinder, G Dahl, N TI Identification of microdeletions spanning the Diamond-Blackfan anemia locus on 19q13 and evidence for genetic heterogeneity SO AMERICAN JOURNAL OF HUMAN GENETICS LA English DT Article ID CONGENITAL HYPOPLASTIC-ANEMIA; RED-CELL APLASIA; CLUSTER; FAMILY; HUMAN-CHROMOSOME-19; TRANSMISSION; MAP AB Diamond-Blackfan anemia (DBA) is a rare pure red-cell hypoplasia of unknown etiology and pathogenesis. A major DBA locus has previously been localized to chromosome 19q13.2. Samples from additional families have been collected to identify key recombinations, microdeletions, and the possibility of heterogeneity for the disorder. In total, 29 multiplex DBA families and 50 families that comprise sporadic DBA cases have been analyzed with polymorphic 19q13 markers, including a newly identified short-tandem repeat in the critical gene region. The results from DNA analysis of 23 multiplex families revealed that 26 of these were consistent with a DBA gene on 19q localized to within a 4.1-cM interval restricted by loci D19S200 and D19S178; however, in three multiplex families, the DBA candidate region on 19q13 was excluded from the segregation of marker alleles. Our results suggest genetic heterogeneity for DBA, and we show that a gene region on chromosome 19q segregates with the disease in the majority of familial cases. Among the 50 families comprising sporadic DBA cases, we identified two novel and overlapping microdeletions on chromosome 19q13. In combination, the three known, microdeletions associated with. DBA restrict the critical gene region to similar to 1 Mb. The results indicate that a proportion of sporadic DBA cases are caused by deletions in the 19q13 region. C1 Uppsala Univ, Childrens Hosp, Dept Genet & Pathol, Clin Genet Unit, Uppsala, Sweden. Univ Turin, Dept Pediat, Turin, Italy. Univ Turin, Dept Genet, Turin, Italy. St George Hosp, Sch Med, Dept Haematol, London, England. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Life Sci, Berkeley, CA USA. Hop Bicetre, APHP, Fac Med, Dept Hematol, Bicetre, France. St Christophers Hosp Children, Dept Lab Med, Philadelphia, PA 19133 USA. St Christophers Hosp Children, Dept Pediat, Philadelphia, PA 19133 USA. Univ Ulm, Dept Pediat, D-7900 Ulm, Germany. Univ Oslo, Dept Pediat, Oslo, Norway. Univ Erlangen Nurnberg, Dept Human Genet, D-8520 Erlangen, Germany. Hosp Sick Children, Toronto, ON M5G 1X8, Canada. Royal Childrens Hosp, Dept Haematol Oncol, Melbourne, Vic, Australia. Sacchska Hosp, Dept Pediat, Stockholm, Sweden. RP Dahl, N (reprint author), Uppsala Univ, Childrens Hosp, Dept Genet & Pathol, Clin Genet Unit, Uppsala, Sweden. FU Telethon [E.0619] NR 28 TC 52 Z9 52 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0002-9297 J9 AM J HUM GENET JI Am. J. Hum. Genet. PD NOV PY 1998 VL 63 IS 5 BP 1388 EP 1395 DI 10.1086/302100 PG 8 WC Genetics & Heredity SC Genetics & Heredity GA 138QZ UT WOS:000076985200014 PM 9792865 ER PT J AU Fiske, PS Nellis, WJ Xu, Z Stebbins, JF AF Fiske, PS Nellis, WJ Xu, Z Stebbins, JF TI Shocked quartz: A Si-29 magic-angle-spinning nuclear magnetic resonance study SO AMERICAN MINERALOGIST LA English DT Article ID INDUCED COORDINATION CHANGES; PLANAR DEFORMATION FEATURES; ALPHA-QUARTZ; AMORPHOUS SIO2; METEOR CRATER; SILICA GLASS; PRESSURE; TEMPERATURES; STISHOVITE; METAMORPHISM AB Quantitative Si-29 NMR spectra of single-crystal alpha-quartz, shock compressed to 12-38 GPa and recovered, provide new information about the complex response of quartz to shock loading. Spectra from samples recovered from shock pressures of 12-20 GPa show a broadening of the 29Si NMR peak and the development of asymmetry toward lower NMR frequency (indicating an increase in the mean Si-O-Si intertetrahedral bond angle). NMR spectra of samples shock compressed above similar to 25 GPa show increasing amounts of a separate amorphous phase of SiO2 with a mean Si-O-Si bond angle roughly 5 degrees narrower, and 10-15% denser, than fused SiO2. Small amounts of crystalline material remain with a mean Si-O-Si bond angle up to 3 degrees larger than unshocked a-quartz. The recovery of dense glass indicates that post-shock temperatures were sufficiently low to also preserve stishovite, had any been created in our experiments. The paucity of stishovite or Si-[6] in an amorphous phase in our recovered samples suggests that the formation of stable, high-coordinated Si is kinetically hindered in shock compression experiments up to about 35-40 GPa, except in regions of high temperature, such as planar deformation features (PDFs), microfaults (pseudotachylites), or voids. C1 Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, Livermore, CA 94550 USA. Lawrence Livermore Natl Lab, Dept Engn, Livermore, CA 94550 USA. Stanford Univ, Dept Geol & Environm Sci, Stanford, CA 94305 USA. RP Fiske, PS (reprint author), Lawrence Livermore Natl Lab, Phys & Space Technol Directorate, L-045, Livermore, CA 94550 USA. EM fiske1@llnl.gov NR 49 TC 15 Z9 15 U1 1 U2 18 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1998 VL 83 IS 11-12 BP 1285 EP 1292 PN 1 PG 8 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 146CN UT WOS:000077410500017 ER PT J AU Zhang, CL Vali, H Romanek, CS Phelps, TJ Liu, SV AF Zhang, CL Vali, H Romanek, CS Phelps, TJ Liu, SV TI Formation of single-domain magnetite by a thermophilic bacterium SO AMERICAN MINERALOGIST LA English DT Article ID IRON-REDUCING BACTERIA; FE(III)-REDUCING BACTERIA; ENVIRONMENTAL SIGNIFICANCE; MAGNETOTACTIC BACTERIUM; BIOGENIC MAGNETITE; MINERAL FORMATION; DEEP SUBSURFACE; SP-NOV; SEDIMENTS; MAGNETIZATION AB Magnetite is a common product of bacterial iron reduction and may serve as a potential physical indicator of biological activity in geological settings. Here we report the formation of single-domain magnetite under laboratory conditions by a thermophilic fermentative bacterial strain TOR-39 that was isolated from the deep subsurface. Time-course analyses were performed at 65 degrees C to study the effect of bacterial activity on solution chemistry and magnetite formation during the growth of TOR-39. Run products were examined by transmission electron microscopy. Magnetite particles formed exclusively outside of bacterial cells and exhibited octahedral shapes having relatively equal length and width (<15% difference). Tiny magnetite particles (<12 nm) nucleated between 10 and 11 h of incubation and increased to average lengths of 55.4 +/- 26.8 nm after 24 h of incubation. Between 24 h and 22 d of incubation, magnetite particles maintained average lengths of 56.2 +/- 24.8 MI. Based on size constraints, greater than 85% of the particles observed fell within the magnetic single domain. Little to no magnetite was detected in abiotic controls at 65 or 95 degrees C, or in TOR-39 cultures whose activity was suppressed. Unlike mesophilic iron-reducing bacteria (e.g., GS-15), TOR-39 produced crystals having shapes and sizes similar to some particles produced intracellularly by magnetotactic bacteria. Thus the single-domain magnetite produced by thermophiles such as TOR-39 may represent a heretofore unrecognized biological contribution to natural remanent magnetization in sedimentary basins and other geothermal environments. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. McGill Univ, Ctr Electron Microscopy, Montreal, PQ H3A 2B2, Canada. Univ Georgia, Savannah River Ecol Lab, Aiken, SC 29802 USA. Univ Georgia, Dept Geol, Aiken, SC 29802 USA. Allegheny Univ Hlth Sci, Dept Microbiol & Immunol, Philadelphia, PA 19129 USA. RP Zhang, CL (reprint author), Univ Missouri, Dept Geol Sci, Columbia, MO 65211 USA. EM geoscc2@showme.missouri.edu RI phelps, tommy/A-5244-2011; Vali, Hojatollah/F-3511-2012 OI Vali, Hojatollah/0000-0003-3464-9943 NR 68 TC 76 Z9 80 U1 2 U2 6 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1998 VL 83 IS 11-12 BP 1409 EP 1418 PN 2 PG 10 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 145YE UT WOS:000077399200003 ER PT J AU Zachara, JM Fredrickson, JK Li, SM Kennedy, DW Smith, SC Gassman, PL AF Zachara, JM Fredrickson, JK Li, SM Kennedy, DW Smith, SC Gassman, PL TI Bacterial reduction of crystalline Fe3+ oxides in single phase suspensions and subsurface materials SO AMERICAN MINERALOGIST LA English DT Article ID AQUATIC SEDIMENTS; IRON-OXIDES; THERMAL-DECOMPOSITION; PHOSPHATE ADSORPTION; MICROBIAL REDUCTION; DIAGENETIC SIDERITE; SURFACE-AREA; FERRIC IRON; DISSOLUTION; GOETHITE AB Microbiologic reduction of synthetic and geologic Fe3+ oxides associated with four Pleistocene-age, Atlantic coastal plain sediments was investigated using a dissimilatory Fe reducing bacterium (Shewanella purrefaciens, strain CN32) in bicarbonate buffer. Experiments investigated whether phosphate and anthraquinone-2, 6-disulfonate, (AQDS, a humic acid analogue) influenced the extent of crystalline Fe3+ oxide bioreduction and whether crystalline Fe3+ oxides in geologic materials are more or less reducible than comparable synthetic phases. Anaerobic incubations (10(8) organisms/mL) were performed both with and without PO, and AQDS that functions as an electron repository and shuttle. The production of Fe2+ (solid and aqueous) was followed with time, as was mineralogy by Xray diffraction. The synthetic oxides were reduced in a qualitative trend consistent with their surface area and free energy: hydrous ferric oxide (HFO)>goethite>hematite. Bacterial reduction of the crystalline oxides was incomplete in spite of excess electron donor. Biogenic formation of vivianite [Fe-3(PO4)(2). 8H(2)O] and siderite (FeCO3) was observed; the conditions of their formation was consistent with their solubility. The geologic Fe3+ oxides showed a large range in reducibility, approaching 100% in some materials. The natural oxides were equally or more reducible than their synthetic counterparts, in spite of association with non-reducible mineral phases (e.g., kaolinite). The reducibility of the synthetic and geologic oxides was weakly effected by PO4, but was accelerated by AQDS. CN32 produced the hydroquinone form of AQDS (AHDS), that, in turn, had thermodynamic power to reduce the Fe3+ oxides. As a chemical reductant, it could reach physical regions of the oxide not accessible by the organism. Electron microscopy showed that crystallite size was not the primary factor that caused differences in reducibility between natural and synthetic crystalline Fe3+ oxide phases. Crystalline disorder and microheterogeneities may be more important. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Zachara, JM (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. EM jm_zachara@ppnl.gov OI Kennedy, David/0000-0003-0763-501X NR 69 TC 269 Z9 282 U1 2 U2 48 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1998 VL 83 IS 11-12 BP 1426 EP 1443 PN 2 PG 18 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 145YE UT WOS:000077399200005 ER PT J AU Kohn, MJ Riciputi, LR Stakes, D Orange, DL AF Kohn, MJ Riciputi, LR Stakes, D Orange, DL TI Sulfur isotope variability in biogenic pyrite: Reflections of heterogeneous bacterial colonization? SO AMERICAN MINERALOGIST LA English DT Article ID SULFATE-REDUCING BACTERIA; REACTIONS FORMING PYRITE; ARCHEAN IRON-FORMATIONS; ION MICROPROBE SHRIMP; MONTEREY BAY; LABORATORY SYNTHESIS; FRAMBOIDAL PYRITE; SULFIDE FORMATION; LASER MICROPROBE; S-34/S-32 RATIOS AB The top 20 cm of sediments at active cold seeps in Monterey Bay, coastal California, contain framboidal pyrite that occurs as infillings and pseudomorphs of the chambers of the tests of foraminifera and rarely as irregularly shaped grains. Sulfur isotope compositions obtained with the ion microprobe show depletions in S-34 (delta(34)S = -41 to -5 parts per thousand, CDT), and large variations both within and among these pyrite grains. Intergranular differences in delta(34)S values in the same sediment are as large as 35 parts per thousand, and intragranular zoning reaches 15 parts per thousand. Zoning is regular in some grains, with systematic isotope changes from core to rim or from one foraminiferal chamber to another, but irregular in others. The regular zoning is consistent with an increase in S-34 through time. Backscattered-electron imaging reveals three types of pyrite: isolated framboids in a porous aggregation ("PF-pyrite"), agglomerated framboids with cementing interstitial pyrite ("F+I-pyrite"), and recrystallized pyrite with isolated relicts of framboids ("RF-pyrite"). In individual grains, RF-pyrite cores grade into F+I-pyrite toward grain rims, and F+I-pyrite grades into PF-pyrite at the grain edges. These textures are consistent with a paragenetic sequence whereby framboids first agglomerate (PF-pyrite), then cement (F+I-pyrite), and finally recrystallize (RF-pyrite). The delta(34)S values of RF-pyrite are generally lower than that of F+I-pyrite; if the paragenetic sequence is correct, then this trend parallels the regular core-rim isotopic zoning observed in some grains. The implied increase in delta(34)S With time is consistent with Rayleigh fractionation of sulfur in a closed system. Bacteria are intimately involved in the production of pyrite from our samples, and heterogeneous colonization by bacteria provides a simple explanation for the sulfur isotope heterogeneity among and within grains: The foraminifera provide open space for colonization and local nutrients for bacterial growth, whereas the cell walls of the bacteria may provide a local nucleation site for sulfides. If so, then initial colonization is reflected in lower delta(34)S values, whereas later bacterial emigration to other foraminifera chambers is indicated by higher delta(34)S values. C1 Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Monterey Bay Aquarium Res Inst, Moss Landing, CA 95039 USA. Univ Calif Santa Cruz, Dept Earth Sci, Santa Cruz, CA 95062 USA. RP Kohn, MJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RI Kohn, Matthew/A-2562-2012 NR 61 TC 78 Z9 84 U1 4 U2 17 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1998 VL 83 IS 11-12 BP 1454 EP 1468 PN 2 PG 15 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 145YE UT WOS:000077399200007 ER PT J AU Siering, PL AF Siering, PL TI The double helix meets the crystal lattice: The power and pitfalls of nucleic acid approaches for biomineralogical investigations SO AMERICAN MINERALOGIST LA English DT Review ID IN-SITU HYBRIDIZATION; RIBOSOMAL-RNA GENES; TARGETED OLIGONUCLEOTIDE PROBES; POLYMERASE CHAIN-REACTION; WHOLE-CELL HYBRIDIZATION; TYRAMIDE SIGNAL AMPLIFICATION; AMMONIUM-OXIDIZING BACTERIA; SULFATE-REDUCING BACTERIA; FLOW CYTOMETRIC DETECTION; ACTIVATED-SLUDGE AB The inability to culture the majority of microorganisms from natural habitats has been well. documented. In response to this constraint, the development and application of culture-independent methods for studying microbial communities have been a focus of microbial ecology for the past several years. Molecular approaches, in particular, offer great potential to investigate the role of microorganisms in areas as diverse as biogeochemistry, pollutant remediation, and disease causation. The purpose of this review is to give a brief critique of nucleic acid-based techniques currently used in microbial ecology, to serve as a reference for those wishing to employ such techniques, and to examine the applicability of these techniques toward studying the biogeochemical roles of bacteria, especially as related to metal cycling and biomineralization. Although published reports on the application of molecular techniques to biogeochemical and biomineralogical problems are scarce, this review aims to familiarize biogeochemists and biomineralogists with the strengths and weaknesses of these approaches. Advances have been made in describing the diversity of uncultured microbial communities, detecting/identifying specific cells and functional genes in environmental samples, detecting in situ activities of specific microorganisms, and determining some of the factors controlling gene expression in in vitro studies. However, the current methods provide limited quantitative information about natural processes. Acknowledging these limitations can assist the development of methods to answer basic questions concerning the in situ distribution and activities of microorganisms. Studies relating these in situ measurements of microbial activity and distribution to the physical and chemical microenvironment will ultimately permit a better understanding of the importance of microorganisms in mineral formation and dissolution processes. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Environm & Engn Lab, Dept Biotechnol, Idaho Falls, ID 83415 USA. RP Siering, PL (reprint author), Humboldt State Univ, Dept Sci Biol, Arcata, CA 95521 USA. EM pls13@axe.humboldt.edu NR 149 TC 9 Z9 9 U1 0 U2 8 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1015 EIGHTEENTH ST, NW SUITE 601, WASHINGTON, DC 20036 USA SN 0003-004X J9 AM MINERAL JI Am. Miner. PD NOV-DEC PY 1998 VL 83 IS 11-12 BP 1593 EP 1607 PN 2 PG 15 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA 145YE UT WOS:000077399200020 ER PT J AU Duckworth, DC Barshick, CM AF Duckworth, DC Barshick, CM TI Ion traps: What be they hold for elemental mass analysis? SO ANALYTICAL CHEMISTRY LA English DT Article ID INDUCTIVELY-COUPLED PLASMA; FOURIER-TRANSFORM; HIGH-RESOLUTION; SPECTROMETRY; EXCITATION; SPECTROSCOPY; MIXTURES C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Barshick, CM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. EM barshickcm@ornl.gov RI Duckworth, Douglas/B-7171-2015 OI Duckworth, Douglas/0000-0002-8161-5685 NR 38 TC 9 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 1 PY 1998 VL 70 IS 21 BP 709A EP 717A PG 9 WC Chemistry, Analytical SC Chemistry GA 136BX UT WOS:000076839000006 ER PT J AU Van Orden, A Keller, RA AF Van Orden, A Keller, RA TI Fluorescence correlation spectroscopy for rapid multicomponent analysis in a capillary electrophoresis system SO ANALYTICAL CHEMISTRY LA English DT Article ID LARGE DNA; MOBILITY; DIFFUSION; KINETICS; PATTERN AB We describe a new technique for performing multicomponent analysis using a combination of capillary electrophoresis (CE) and fluorescence correlation spectroscopy (FCS), which we refer to as CE/FCS, FCS is a highly sensitive and rapid optical technique that is often used to perform multicomponent analysis in static solutions based on the different diffusion times of the analyte species through the detection region of a tightly focused laser beam. In CE/FCS, transit times are measured for a mixture of analytes continuously flowing through a microcapillary in the presence of an electric field. Application of an electric field between the inlet and outlet of the capillary alters the transit times, depending on the magnitude and polarity of the applied held and the electrophoretic mobilities of the analytes, Multicomponent analysis is accomplished without the need to perform a chemical separation, due to the different electrophoretic mobilities of the analytes, This technique is particularly applicable to ultradilute solutions of analyte. We have used CE/FCS to analyze subnanomolar aqueous solutions containing mixtures of Rhodamine 6G (R6G) and R6G-labeled deoxycytosine triphosphate nucleotides, Under these conditions, fewer than two molecules were typically present in the detection region at a time. The relative concentrations of the analytes were determined with uncertainties of similar to 10%, Like diffusional FCS, this technique is highly sensitive and rapid. Concentration detection limits are below 10(-11) M, and analysis times are tens of seconds or less. However, CE/FCS does not require the diffusion coefficients of the analytes to be significantly different and can, therefore, be applied to multicomponent analysis of systems that would be difficult or impossible to study by diffusional FCS. C1 Univ Calif Los Alamos Natl Lab, Dept Chem Sci & Technol, Los Alamos, NM 87545 USA. RP Keller, RA (reprint author), Univ Calif Los Alamos Natl Lab, Dept Chem Sci & Technol, MS M888, Los Alamos, NM 87545 USA. RI Van Orden, Alan/N-4219-2015 NR 24 TC 26 Z9 27 U1 5 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 1 PY 1998 VL 70 IS 21 BP 4463 EP 4471 DI 10.1021/ac980768q PG 9 WC Chemistry, Analytical SC Chemistry GA 136BX UT WOS:000076839000012 PM 21644691 ER PT J AU Ermakov, SV Jacobson, SC Ramsey, JM AF Ermakov, SV Jacobson, SC Ramsey, JM TI Computer simulations of electrokinetic transport in microfabricated channel structures SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY ZONE ELECTROPHORESIS; CYCLIC PLANAR MICROSTRUCTURE; GLASS CHIPS; EXPERIMENTAL VALIDATION; SAMPLE INJECTION; POSTCOLUMN REACTOR; MICROCHIP DEVICE; SYSTEMS; SEPARATIONS; PROTEINS C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Ramsey, JM (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008, Oak Ridge, TN 37831 USA. NR 57 TC 185 Z9 188 U1 2 U2 16 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD NOV 1 PY 1998 VL 70 IS 21 BP 4494 EP 4504 DI 10.1021/ac980551w PG 11 WC Chemistry, Analytical SC Chemistry GA 136BX UT WOS:000076839000016 PM 21644694 ER PT J AU Pronk, AF Stigter, J Stouthamer, AH de Bruijn, FJ Boogerd, FC AF Pronk, AF Stigter, J Stouthamer, AH de Bruijn, FJ Boogerd, FC TI Coproporphyrin excretion by Azorhizobium caulinodans under micro-aerobic conditions SO ANTONIE VAN LEEUWENHOEK INTERNATIONAL JOURNAL OF GENERAL AND MOLECULAR MICROBIOLOGY LA English DT Article DE Azorhizobium caulinodans; coproporphyrin; micro-aerobiosis; excretion; fixLJ; fixK ID NITROGEN-FIXATION; III OXIDASE; ESCHERICHIA-COLI; RHODOBACTER-SPHAEROIDES; RHIZOBIUM-JAPONICUM; GENE; CLONING; HEMF; PURIFICATION; MUTAGENESIS AB Azorhizobium caulinodans ORS571 was found to excrete moderate amounts of a fluorescent pigment into the culture medium in response to dissolved oxygen tensions below 1.0 kPa. The pigment was identified as coproporphyrin, on the basis of its optical and fluorescence spectra. FixLJ and fixK mutant derivatives of ORS571 were found to excrete 25-fold higher amounts of coproporphyrin under micro-aerobic conditions than the wild type strain. These observations suggest that A. caulinodans switches from an aerobic to an anaerobic coproporphyrinogen oxidase when the dissolved oxygen tension falls below 1.0 kPa and that the fixLJ and fixK genes are involved in the regulation of expression of the anaerobic coproporphyrinogen oxidase. C1 Vrije Univ Amsterdam, BioCtr Amsterdam, Dept Mol Cell Physiol, Amsterdam, Netherlands. Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. Michigan State Univ, Dept Microbiol, E Lansing, MI 48824 USA. RP Boogerd, FC (reprint author), Vrije Univ Amsterdam, BioCtr Amsterdam, Dept Mol Cell Physiol, Amsterdam, Netherlands. NR 30 TC 2 Z9 2 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0003-6072 J9 ANTON LEEUW INT J G JI Antonie Van Leeuwenhoek PD NOV PY 1998 VL 74 IS 4 BP 245 EP 251 DI 10.1023/A:1001734626121 PG 7 WC Microbiology SC Microbiology GA 169NB UT WOS:000078754500006 PM 10081584 ER PT J AU Stoner, DL Miller, KS Fife, DJ Larsen, ED Tolle, CR Johnson, JA AF Stoner, DL Miller, KS Fife, DJ Larsen, ED Tolle, CR Johnson, JA TI Use of an intelligent control system to evaluate multiparametric effects on iron oxidation by thermophilic bacteria SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID OXIDIZING BACTERIA; SP-NOV; FERROOXIDANS; PYRITE; GROWTH AB A learning-based intelligent control system, the BioExpert, was developed and applied to the evaluation of multiparametric effects on iron oxidation by enrichment cultures of moderately thermophilic, acidophilic mining bacteria. The control system acquired and analyzed the data and then selected and maintained the sets of conditions that were evaluated. Through multiple iterations, the BioExpert selected sets of conditions that resulted in improved iron oxidation rates. The results obtained with the BioExpert suggested that temperature and pH were coupled, or interactive, parameters. Elevated temperatures (51.5 degrees C) in combination with a moderately high pH (pH 1.84) impaired the growth of and iron oxidation by the enrichment culture. Moderate-to-high oxidation rates were achieved,vith a relatively high pH in combination with a relatively low temperature or, conversely, with a relatively low pH in combination with a relatively high temperature. The interactive effect of pH and temperature was not apparent from the results obtained in an experiment in which temperature was the only parameter that was varied. When the BioExpert was applied to a mixed culture containing mesophilic and thermophilic bacteria, the computer "learned" that pH 1.8, 45 degrees C, and an inlet iron concentration from 30 to 35 mM were most favorable for iron oxidation. In conclusion, this study demonstrated that the learning-based intelligent control system BioExpert was an effective experimental tool that can be used to examine multiparametric effects on the growth and metabolic activity of mining bacteria. C1 Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Biotechnol Grp, Idaho Falls, ID 83415 USA. Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Mat Phys Grp, Idaho Falls, ID 83415 USA. RP Stoner, DL (reprint author), Lockheed Martin Idaho Technol Co, Idaho Natl Engn & Environm Lab, Biotechnol Grp, POB 1625, Idaho Falls, ID 83415 USA. EM dstoner@inel.gov NR 40 TC 5 Z9 5 U1 0 U2 0 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 USA SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD NOV PY 1998 VL 64 IS 11 BP 4555 EP 4565 PG 11 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA 133PD UT WOS:000076694200068 ER PT J AU Solodov, IN Zotov, AV Khoteev, AD Mukhamet-Galeev, AP Tagirov, BR Apps, JA AF Solodov, IN Zotov, AV Khoteev, AD Mukhamet-Galeev, AP Tagirov, BR Apps, JA TI Geochemistry of natural and contaminated subsurface waters in fissured bed rocks of the Lake Karachai area, Southern Urals, Russia SO APPLIED GEOCHEMISTRY LA English DT Article AB Hydrogeochemical investigations of natural and contaminated subsurface waters were conducted between 1992-94 in an area where liquid radioactive waste (RAW) was impounded in a small lake, and subsequently leaked into an underlying water bearing horizon. The waste was discharged from the radiochemical plant of the Mayak Amalgamated Industry near Chelyabinsk, Russia. The underlying water-bearing horizon in fissured metavolcanic rocks was penetrated by uncased observation wells in order to log the hydrogeochemistry. Logging was carried out using a specially designed hydrogeochemical probe. which contained 8 channels to measure continuously the temperature, pressure, electric conductivity, pH, Eh, the dissolved O-2 concentration, and the activities of Na, and NO3 in the wells. The logging technique enabled the natural hydrogeochemical setting to be characterized and permitted delineation of bodies of contaminated waters of different origins using measurements of, pH, pNa and pNO(3). The technique also permitted an evaluation of variations in the chemical composition of the RAW solutions due to radiolytic processes and to chemical interactions with the geologic medium. A conceptual model is proposed for the chemical evolution of the migrating contaminated subsurface waters in the area investigated. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Russian Acad Sci, Inst Ore Deposit Geol Petrog Mineral & Geoche, Moscow, Russia. Univ Calif Los Alamos Natl Lab, Div Earth Sci, Los Alamos, NM 87545 USA. RP Solodov, IN (reprint author), Russian Acad Sci, Inst Ore Deposit Geol Petrog Mineral & Geoche, Moscow, Russia. NR 32 TC 10 Z9 11 U1 3 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD NOV PY 1998 VL 13 IS 8 BP 921 EP 939 DI 10.1016/S0883-2927(98)00025-0 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA 147GK UT WOS:000077480600001 ER PT J AU Meriaudeau, F Goudonnet, JP Carver, E Parks, JE Jacobson, KB Warmack, RJ Ferrell, TL AF Meriaudeau, F Goudonnet, JP Carver, E Parks, JE Jacobson, KB Warmack, RJ Ferrell, TL TI Photon scanning-tunneling microscopy of unstained mammalian cells and chromosomes SO APPLIED OPTICS LA English DT Article ID OPTICAL MICROSCOPY AB The photon scanning-tunneling microscope (PSTM) yields optical topographical images of samples that are thin or that are transparent at the wavelength used. A range of sample sizes can be imaged extending to well below the diffraction Limit for sufficiently flat samples. But samples of the order of several to many micrometers in size can be analyzed with less-refined resolution if total internal reflection can be made to occur in the sample. We used the PSTM to examine the optical topography of mouse and human cells and of chromosomes that are unstained. Our objectives were to demonstrate the images as an alternative to conventional microscopy and to provide a sample-preparation methodology that will later permit localized, simultaneous fluorescence or absorption spectroscopy with the signals collected by the probe tip. Furthermore, the PSTM's ability to produce optical profiles in air and in water was tested to establish the basis for future investigation of possible abnormalities in the chromosomes. That is, we considered both physical and biological objectives. To this end we utilized the 442-nm line of a He-Cd laser as well as the 633-nm line from a He-Ne laser, the resulting image quality being tested partly to ascertain the increased effects of scattering at the smaller wavelength. It is shown that adequate resolution and signal-to-noise ratio can be obtained with the shorter wavelength Even in the presence of intensity fluctuations from the laser, thus showing that fluorescence and absorption studies can be expected to be practicable. (C) 1998 Optical Society of America OCIS codes: 170.1530, 180.0180, 180.5810. C1 Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. LE21 Lab, F-71200 Le Creusot, France. Univ Bourgogne, Lab Photoelect, F-21004 Dijon, France. RP Meriaudeau, F (reprint author), Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. NR 23 TC 1 Z9 1 U1 1 U2 2 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 NOV 1 PY 1998 VL 37 IS 31 BP 7276 EP 7288 DI 10.1364/AO.37.007276 PG 13 WC Optics SC Optics GA 134VJ UT WOS:000076764100018 PM 18301559 ER PT J AU Isidorsson, J Granqvist, CG von Rottkay, K Rubin, M AF Isidorsson, J Granqvist, CG von Rottkay, K Rubin, M TI Ellipsometry on sputter-deposited tin oxide films: optical constants versus stoichiometry, hydrogen content, and amount of electrochemically intercalated lithium SO APPLIED OPTICS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; EFFECTIVE-MEDIUM MODELS; SPECTROSCOPIC ELLIPSOMETRY; TRANSPARENT ELECTRODES; SURFACE-ROUGHNESS; SN OXIDE; ELECTROCHROMISM; REFLECTANCE; CAPACITY; INDEXES AB Tin oxide thin films were deposited by reactive radio-frequency magnetron sputtering onto In2O3:Sn-coated and bare glass substrates. Optical constants in the 300-2500-nm wavelength range were determined by a combination of variable-angle spectroscopic ellipsometry and spectrophotometric transmittance measurements. Surface roughness was modeled from optical measurements and compared with atomic-force microscopy. The two techniques gave consistent results. The fit between experimental optical data and model results could be significantly improved when it was assumed that; the refractive index of the Sn oxide varied across the film thickness. Varying the oxygen partial pressure during deposition made it possible to obtain films whose complex refractive index changed at the transition from SnO to SnO2. An addition of hydrogen gas during sputtering led to lower optical constants in the full spectral range in connection with a blueshift of the bandgap. Electrochemical intercalation of lithium ions into the Sn oxide films raised their refractive index and enhanced their refractive-index gradient. (C) 1998 Optical Society of America OCIS codes: 310.0310, 120.4530, 120.2130. C1 Univ Uppsala, Angstrom Lab, Dept Mat Sci, S-75121 Uppsala, Sweden. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Isidorsson, J (reprint author), Univ Uppsala, Angstrom Lab, Dept Mat Sci, POB 534, S-75121 Uppsala, Sweden. NR 35 TC 24 Z9 24 U1 1 U2 8 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 NOV 1 PY 1998 VL 37 IS 31 BP 7334 EP 7341 DI 10.1364/AO.37.007334 PG 8 WC Optics SC Optics GA 134VJ UT WOS:000076764100026 PM 18301567 ER PT J AU Niles, DW Waters, D Rose, D AF Niles, DW Waters, D Rose, D TI Chemical reactivity of CdCl2 wet-deposited on CdTe films studied by X-ray photoelectron spectroscopy SO APPLIED SURFACE SCIENCE LA English DT Article DE CdTe; CdO; TeO2; CdTeO3; CdCl2; surface chemistry; X-ray photoelectron spectroscopy; photovoltaic; solar cells ID ANODIC OXIDE-FILMS; SOLAR-CELLS; THIN-FILMS; TE; HG0.8CD0.2TE; OXIDATION; DEVICES AB The authors use X-ray photoelectron spectroscopy to investigate the chemical reactivity of CdTe films exposed to a solution of CdCl2 dissolved in methanol. They show that annealing in vacuum does not instigate a chemical reaction between CdCl2 and CdTe, but that annealing in either He:O-2 or pure He leads to the formation of a surface Cl residue comprising Cd, Te, Cl, and O in the form of oxides and oxychlorides. From detailed analysis of X-ray photoelectron data, they propose that CdO, TeO2, TeCl2O are building blocks for the surface Cl residue. (C) 1998 Published by Elsevier Science B.V. All rights reserved. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Niles, DW (reprint author), Hewlett Packard, 3404 E Harmony Rd,MS 64, Ft Collins, CO 80528 USA. NR 25 TC 30 Z9 30 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD NOV PY 1998 VL 136 IS 3 BP 221 EP 229 DI 10.1016/S0169-4332(98)00340-7 PG 9 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA 140QW UT WOS:000077100700007 ER PT J AU Messer, OEB Mezzacappa, A Bruenn, SW Guidry, MW AF Messer, OEB Mezzacappa, A Bruenn, SW Guidry, MW TI A comparison of Boltzmann and multigroup flux-limited diffusion neutrino transport during the postbounce shock reheating phase in core-collapse supernovae SO ASTROPHYSICAL JOURNAL LA English DT Article DE diffusion; stars : interiors; supernovae : general ID II SUPERNOVAE; EXPLOSIONS; EQUATION; CONVECTION; STATE AB We compare Newtonian three-flavor multigroup Boltzmann (MGBT) and (Bruenn's) multigroup flux-limited diffusion (MGFLD) neutrino transport in postbounce core-collapse supernova environments. We focus our study on quantities central to the postbounce neutrino heating mechanism for reviving the stalled shock. Stationary-state three-flavor neutrino distributions are developed in thermally and hydrodynamically frozen time slices obtained from core collapse and bounce simulations that implement Lagrangian hydrodynamics and MGFLD neutrino transport. We obtain distributions for time slices at 106 and 233 ms after core bounce for the core of a 15 M. progenitor, and at 156 ms after core bounce for a 25 M. progenitor. For both transport methods, the electron neutrino and antineutrino luminosities, rms energies, and mean inverse flux factors, all of which enter the neutrino heating rates, are computed as functions of radius and compared. The net neutrino heating rates are also computed as functions of radius and compared. Notably, we find significant differences in neutrino luminosities and mean inverse flux factors between the two transport methods for both precollapse models and for all three time slices. In each case, the luminosities for each transport method begin to diverge above the neutrinospheres, where the MGBT luminosities become larger than their MGFLD counterparts, finally settling to a constant difference maintained to the edge of the core. We find that the mean inverse flux factors, which describe the degree of forward peaking in the neutrino radiation held, also differ significantly between the two transport methods, with MGBT providing more isotropic radiation fields in the gain region. Most important, for a region above the gain radius we find net heating rates for MGBT that are as much as similar to 2 times the corresponding MGFLD rates, and we find net cooling rates below the gain radius that are typically similar to 0.8 times the MGFLD rates. These differences stem from differences in the neutrino luminosities and mean inverse flux factors, which can be as much as 11% and 24%, respectively. They are greatest at earlier postbounce times for a given progenitor mass and, for a given postbounce time, greater for greater progenitor mass. We discuss the ramifications that these new results have for the supernova mechanism. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. RP Messer, OEB (reprint author), Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RI Messer, Bronson/G-1848-2012; Mezzacappa, Anthony/B-3163-2017 OI Messer, Bronson/0000-0002-5358-5415; Mezzacappa, Anthony/0000-0001-9816-9741 NR 30 TC 53 Z9 53 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 SOUTH WOODLAWN AVE, CHICAGO, IL 60637-1603 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD NOV 1 PY 1998 VL 507 IS 1 BP 353 EP 360 DI 10.1086/306323 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA 152LQ UT WOS:000077779400034 ER PT J AU Fournier, KB Cohen, M May, MJ Goldstein, WH AF Fournier, KB Cohen, M May, MJ Goldstein, WH TI Ionization state distribution and radiative cooling rate for argon in a low-density plasma SO ATOMIC DATA AND NUCLEAR DATA TABLES LA English DT Article ID ATOMIC PROCESSES; CROSS-SECTIONS; SPECTROSCOPY; IMPURITIES; ITER AB This paper presents the coronal ionization state distribution for argon. The calculations include ab initio rate coefficients for collisional excitation followed by autoionization (EA), and rates for direct ionization and dielectronic and radiative recombination. The EA rate coefficients have been fitted to analytical expressions, and the fitting coefficients are tabulated. The paper then presents the calculated radiative cooling coefficient for argon ions in a low-density plasma as a function of temperature. The channels for power loss from argon ions include collisional-radiative (CR) line emission, dielectronic and radiative recombination, and bremsstrahlung emission. The power emitted via CR line emission for each ion is tabulated on a grid of temperatures and densities. The total power loss coefficient is fitted to an analytical expression in powers of the temperature. (C) 1998 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Hebrew Univ Jerusalem, Racah Inst Phys, IL-91904 Jerusalem, Israel. RP Fournier, KB (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 18 TC 26 Z9 26 U1 1 U2 2 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0092-640X J9 ATOM DATA NUCL DATA JI Atom. Data Nucl. Data Tables PD NOV PY 1998 VL 70 IS 2 BP 231 EP 254 DI 10.1006/adnd.1998.0793 PG 24 WC Physics, Atomic, Molecular & Chemical; Physics, Nuclear SC Physics GA 162MP UT WOS:000078351000003 ER PT J AU Kuhl, TL Majewski, J Wong, JY Steinberg, S Leckband, DE Israelachvili, JN Smith, GS AF Kuhl, TL Majewski, J Wong, JY Steinberg, S Leckband, DE Israelachvili, JN Smith, GS TI A neutron reflectivity study of polymer-modified phospholipid monolayers at the solid-solution interface: Polyethylene glycol-lipids on silane-modified substrates SO BIOPHYSICAL JOURNAL LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; POLY(ETHYLENE GLYCOL); INTERACTION FORCES; MIXED MONOLAYERS; SILICON; LIPOSOMES; SURFACES; BILAYERS; ELLIPSOMETRY; SPECTROSCOPY AB The structure of polymer-decorated phospholipid monolayers at the solid-solution interface was investigated using neutron reflectometry. The monolayers were composed of distearoylphosphatidylethanolamine (DSPE) matrixed with varying amounts of DSPE-PEG (DSPE with polyethylene glycol covalently grafted to its headgroup). Mixed lipid monolayers were Langmuir-Blodgett deposited onto hydrophobic quartz or silicon substrates, previously hydrophobized by chemically grafting a robust monolayer of octadecyltrichlorosilane (OTS). We show that this method results in homogeneous and continuous phospholipid monolayers on the silanated substrates and determine that the grafted PEG chains extend away from the monolayers into the solvent phase as a function of their density, as expected from scaling theories. In addition, ligands were coupled to the end of the PEG chains and selective binding was demonstrated using fluorescence microscopy. Our results demonstrate that these constructs are ideal for further characterization and studies with well-defined monomolecular films. C1 Univ Calif Los Alamos Natl Lab, MLNSC, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. Univ Illinois, Dept Chem Engn, Urbana, IL 61801 USA. RP Smith, GS (reprint author), Univ Calif Los Alamos Natl Lab, MLNSC, H805, Los Alamos, NM 87545 USA. RI Wong, Joyce/F-3732-2011; Lujan Center, LANL/G-4896-2012 OI Wong, Joyce/0000-0002-3526-6381; FU NIGMS NIH HHS [GM 47334] NR 42 TC 67 Z9 69 U1 1 U2 28 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 1998 VL 75 IS 5 BP 2352 EP 2362 PG 11 WC Biophysics SC Biophysics GA 132PF UT WOS:000076638200025 PM 9788930 ER PT J AU Majewski, J Wong, JY Park, CK Seitz, M Israelachvili, JN Smith, GS AF Majewski, J Wong, JY Park, CK Seitz, M Israelachvili, JN Smith, GS TI Structural studies of polymer-cushioned lipid bilayers SO BIOPHYSICAL JOURNAL LA English DT Article ID SUPPORTED PHOSPHOLIPID-BILAYERS; MEMBRANES; MONOLAYER; SYSTEM; FUSION; GLASS; MODEL; FORCE AB The structure of softly supported polymer-cushioned lipid bilayers, prepared in two different ways at the quartz-solution interface, were determined using neutron reflectometry, The polymer cushion consisted of a thin layer of branched, cationic polyethyleneimine (PEI), and the bilayers were formed by adsorption of small unilamellar dimyristoylphosphatidylcholine (DMPC) vesicles. When vesicles were first allowed to adsorb to a bare quartz substrate, an almost perfect bilayer formed. When the polymer was then added to the aqueous solution, it appeared to diffuse beneath this bilayer, effectively lifting it from the substrate. In contrast, if the polymer layer is adsorbed first to the bare quartz substrate followed by addition of vesicles to the solution, there is very little interaction of the vesicles with the polymer layer, and the result is a complex structure most likely consisting of patchy multilayers or adsorbed vesicles. C1 Univ Calif Los Alamos Natl Lab, MLNSC, Los Alamos, NM 87545 USA. Univ Calif Santa Barbara, Dept Chem Engn, Santa Barbara, CA 93106 USA. RP Smith, GS (reprint author), Univ Calif Los Alamos Natl Lab, MLNSC, H805, Los Alamos, NM 87545 USA. RI Wong, Joyce/F-3732-2011; Lujan Center, LANL/G-4896-2012 OI Wong, Joyce/0000-0002-3526-6381; FU NIGMS NIH HHS [GM 47334, GM17876] NR 18 TC 88 Z9 89 U1 1 U2 16 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD NOV PY 1998 VL 75 IS 5 BP 2363 EP 2367 PG 5 WC Biophysics SC Biophysics GA 132PF UT WOS:000076638200026 PM 9788931 ER PT J AU de Souza, ON Ornstein, RL AF de Souza, ON Ornstein, RL TI Inherent DNA curvature and flexibility correlate with TATA box functionality SO BIOPOLYMERS LA English DT Article DE molecular dynamics; DNA curvature; DNA flexibility; TATA box functionality; TATA box binding protein (TBP); TBP recognition; TBP binding; TBP transcriptional activation ID MOLECULAR-DYNAMICS SIMULATIONS; PARTICLE-MESH EWALD; RNA POLYMERASE-II; MINOR-GROOVE; B-DNA; BINDING-PROTEIN; CRYSTAL-STRUCTURE; AQUEOUS-SOLUTION; NUCLEIC-ACIDS; ADENINE TRACT AB Four 1.5 ns molecular dynamics (MD) simulations were performed on the d(GCTATA-AAAGGG).d(CCCTTTTATAGC) double helix dodecamer bearing the Adenovirus major late promoter TATA element and three iso-composition mutants for which physical and biochemical data are available from the same laboratory. Three of these DNA sequences experimentally induce tight binding with the TATA box binding protein (TBP) and induce high transcription rates; the other DNA sequence induces much lower TBP binding and transcription. The x-ray crystal structures have previously shown that the duplex DNA in DNA-TBP complexes are highly bent. We performed and analyzed MD simulations for these four DNAs, whose experimental structures are not available, in order to address the issue of whether inherent DNA structure and flexibility play a role in establishing these observed preferences. A comparison of the experimental and simulated results demonstrated that DNA duplex sequence-dependent curvature and flexibility play a significant role in TBP recognition, binding, and transcriptional activation. (C) 1998 John Wiley & Sons, Inc. C1 Battelle Mem Inst, Pacific NW Div, Richland, WA 99352 USA. RP Ornstein, RL (reprint author), Battelle Mem Inst, Pacific NW Div, Mailstop K2-21, Richland, WA 99352 USA. EM rl_ornstein@pnl.gov RI Norberto de Souza, Osmar/B-7328-2013 OI Norberto de Souza, Osmar/0000-0002-4602-1208 NR 65 TC 36 Z9 37 U1 1 U2 3 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0006-3525 J9 BIOPOLYMERS JI Biopolymers PD NOV PY 1998 VL 46 IS 6 BP 403 EP 415 PG 13 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA 130RQ UT WOS:000076534300005 PM 9798428 ER PT J AU Woodward, J Orr, M AF Woodward, J Orr, M TI Enzymatic conversion of sucrose to hydrogen SO BIOTECHNOLOGY PROGRESS LA English DT Article ID GLUCOSE-DEHYDROGENASE; PYROCOCCUS-FURIOSUS; ARCHAEON; ARCHAEBACTERIUM; PURIFICATION AB The enzymatic conversion of sugars to hydrogen could be a promising method for alternative fuel production. Maple tree sap is a source of environmental sugar (e.g., sucrose) that has the potential to be converted into hydrogen using the enzymes invertase, glucose dehydrogenase (GDH), hydrogenase, and glucose isomerase (GI) and the cofactor NADP(+)/NADPH. The kinetics of hydrogen production have been studied, and optimal conditions for hydrogen production are described. At low initial sucrose concentrations, in the absence of glucose isomerase, stoichiometric yields of 1 mol of H-2/mol of sucrose were achieved. At higher sucrose concentrations, the yield of hydrogen declined so that at an initial sucrose concentration of 292 mM only 7% yield of hydrogen was obtained. The reason for this low yield was studied and shown not to be caused by enzyme inactivation or a pH drop during the reaction but due to an instability of the cofactor NADP(+). Although gluconic acid inhibited both NADPH production and oxidation by GDH and hydrogenase, respectively, it was not the major cause of NADP(+) instability. Fructose was also shown to be converted to hydrogen if GI was present in the reaction mixture. Also, by starting with sucrose, 1.34 mol of H-2/mol of sucrose was obtained if GI was present in the reaction mixture. C1 Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. RP Woodward, J (reprint author), Oak Ridge Natl Lab, Div Chem Technol, Oak Ridge, TN 37831 USA. NR 15 TC 8 Z9 8 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD NOV-DEC PY 1998 VL 14 IS 6 BP 897 EP 902 DI 10.1021/bp980100x PG 6 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA 146QB UT WOS:000077440900011 ER PT J AU Doran, JC Abbott, S Archuleta, J Bian, X Chow, J Coulter, RL de Wekker, SFJ Edgerton, S Elliott, S Fernandez, A Fast, JD Hubbe, JM King, C Langley, D Leach, J Lee, JT Martin, TJ Martinez, D Martinez, JL Mercado, G Mora, V Mulhearn, M Pena, JL Petty, R Porch, W Russell, C Salas, R Shannon, JD Shaw, WJ Sosa, G Tellier, L Templeman, B Watson, JG White, R Whiteman, CD Wolfe, D AF Doran, JC Abbott, S Archuleta, J Bian, X Chow, J Coulter, RL de Wekker, SFJ Edgerton, S Elliott, S Fernandez, A Fast, JD Hubbe, JM King, C Langley, D Leach, J Lee, JT Martin, TJ Martinez, D Martinez, JL Mercado, G Mora, V Mulhearn, M Pena, JL Petty, R Porch, W Russell, C Salas, R Shannon, JD Shaw, WJ Sosa, G Tellier, L Templeman, B Watson, JG White, R Whiteman, CD Wolfe, D TI The IMADA-AVER boundary layer experiment in the Mexico City area SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Article ID AIR-POLLUTION; PROJECT AB A boundary layer field experiment in the Mexico City basin during the period 24 February-22 March 1997 is described. A total of six sites were instrumented. At four of the sites, 915-MHz radar wind profilers were deployed and radiosondes were released five times per day. Two of these sites also had sodars collocated with the profilers. Radiosondes were released twice per day at a fifth site to the south of the basin, and rawinsondes were flown from another location to the northeast of the city three times per day. Mixed layers grew to depths of 2500-3500 m, with a rapid period of growth beginning shortly before noon and lasting for several hours. Significant differences between the mixed-layer temperatures in the basin and outside the basin were observed. Three thermally and topographically driven flow patterns were observed that are consistent with previously hypothesized topographical and thermal forcing mechanisms. Despite these features, the circulation patterns in the basin important for the transport and diffusion of air pollutants show less day-to-day regularity than had been anticipated on the basis of Mexico City's tropical location, high altitude and strong insolation, and topographical setting. C1 Pacific NW Lab, Richland, WA 99352 USA. Environm Technol Lab, Boulder, CO USA. Los Alamos Natl Lab, Los Alamos, NM USA. Univ Nevada, Desert Res Inst, Reno, NV 89506 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Inst Mexicano Petr, Mexico City 07730, DF, Mexico. Univ Nacl Autonoma Mexico, Mexico City 04510, DF, Mexico. Politecn Nacl, Mexico City, DF, Mexico. US DOE, Germantown, MD USA. RP Doran, JC (reprint author), Pacific NW Lab, POB 999,MSIN K9-30, Richland, WA 99352 USA. EM jc_doran@pnl.gov RI Watson, John/E-6869-2010; Sosa, Gustavo/F-3912-2015; OI Watson, John/0000-0002-1752-6899; Sosa, Gustavo/0000-0002-4980-3491; De Wekker, Stephan/0000-0002-6343-854X NR 20 TC 69 Z9 69 U1 1 U2 4 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 USA SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD NOV PY 1998 VL 79 IS 11 BP 2497 EP 2508 DI 10.1175/1520-0477(1998)079<2497:TIABLE>2.0.CO;2 PG 12 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA 143BL UT WOS:000077235200004 ER PT J AU Duff, MC Mason, CFV Hunter, DB AF Duff, MC Mason, CFV Hunter, DB TI Comparison of acid and base leach for the removal of uranium from contaminated soil and catch-box media SO CANADIAN JOURNAL OF SOIL SCIENCE LA English DT Article DE uranium; synchrotron X-ray fluorescence (SXRF); remediation; chromium; lead; leaching; catch-boxes ID X-RAY-FLUORESCENCE; SPECIATION; ADSORPTION; CHEMISTRY; PHASES AB Several leach solutions have been developed for the removal of uranium (U) from contaminated media such as soil and military catch-box sand used for the ballistics testing of U-containing projectiles. Leach solutions of concentrated sulfuric acid and of carbonate (with and without oxidants such as peroxides) have also been used in the mining of U from high-grade ore deposits. Many of these solutions have been used at U-contaminated environmental sites with varying degrees of success. Batch leaches with six characterized U-contaminated media and seven leach solutions were conducted. After the leach solutions were reacted with the media (five soils and a catch-box sand), the solutions were analyzed for dissolved U, Ca, Si, Fe, Mn, Pb and Cr. We study the ability of acidic, basic, acidic-oxidizing and basic-oxidizing solutions to leach U from contaminated media. The results suggest the removal efficiency of soil U for each leach solution varies with the nature of the U-contamination in the media and the media composition. It is likely the forms of U in the contaminated media such as reduced, absorbed, complexed and solid species influence the solubilization of U by the leaching agents. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, Los Alamos, NM 87545 USA. Univ Georgia, Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29801 USA. RP Duff, MC (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div, POB 1663,MS J534, Los Alamos, NM 87545 USA. NR 31 TC 15 Z9 15 U1 1 U2 6 PU AGR INST CANADA PI OTTAWA PA SUITE 907 151 SLATER ST, OTTAWA, ONTARIO K1P 5H4, CANADA SN 0008-4271 J9 CAN J SOIL SCI JI Can. J. Soil Sci. PD NOV PY 1998 VL 78 IS 4 BP 675 EP 683 PG 9 WC Soil Science SC Agriculture GA 152CW UT WOS:000077759000014 ER PT J AU McKellar, AJ Heryadi, D Yeager, DL Nichols, JA AF McKellar, AJ Heryadi, D Yeager, DL Nichols, JA TI Complete basis set limit ionization potentials of O-3 and NO2 using the multiconfigurational spin tensor electron propagator method (MCSTEP) SO CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; OPEN-SHELL SYSTEMS; WAVE-FUNCTIONS; PHOTOELECTRON-SPECTRUM; KOOPMANS THEOREM; EXCITED-STATES; OZONE; ENERGY AB We have calculated low-lying principal vertical ionization potentials (IPs) of O-3 and NO2 with the multiconfigurational spin tensor electron propagator method (MCSTEP) using several different basis sets. We obtain an estimate of complete basis set limit (CBS) MCSTEP IPs. This is the first time CBS estimates have been used with MCSTEP. We show that MCSTEP is accurate and reliable compared with experiment at the CBS limit for obtaining low-lying vertical IPs for open shell molecules such as NO2 and highly correlated molecules such as O-3. Our results confirm previous assignments of photoelectron peaks based on calculations made using less accurate methods. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Texas A&M Univ, Dept Chem, College Stn, TX 77842 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Yeager, DL (reprint author), Texas A&M Univ, Dept Chem, POB 300012, College Stn, TX 77842 USA. RI Yeager, Danny/D-3679-2015; OI Yeager, Danny/0000-0001-9832-0034; Nichols, Jeffrey/0000-0001-5454-9726 NR 44 TC 23 Z9 23 U1 1 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 NOV 1 PY 1998 VL 238 IS 1 BP 1 EP 9 DI 10.1016/S0301-0104(98)00286-9 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA 132AW UT WOS:000076608400001 ER PT J AU Roy, D Hingerty, BE Shapiro, R Broyde, S AF Roy, D Hingerty, BE Shapiro, R Broyde, S TI A slipped replication intermediate model is stabilized by the Syn orientation of N-2-aminofluorene- and N-2-(acetyl)aminofluorene-modified guanine at a mutational hotspot SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID COVALENTLY ATTACHED BENZOPYRENE; CARCINOGENIC HETEROCYCLIC AMINES; INDUCED FRAMESHIFT MUTAGENESIS; -2 DELETION SITE; DNA DUPLEX; SOLUTION CONFORMATION; BASE DISPLACEMENT; ADDUCT OPPOSITE; ESCHERICHIA-COLI; HOT-SPOTS AB The Escherichia coli NarI restriction enzyme recognition site 5'G(1)G(2)C(3)G(4)C(5)C(6)3' is a mutational hotspot for -2 deletions in E. coli plasmid pBR322, resulting in the sequence 5'GGCC3' when G(4) is modified by the aromatic amine N-2-(acetyl)aminofluorene (AAF) [Burnouf, D., Koehl, P., and Fuchs, R. P. P. (1995) Proc. Natl. Acad. Sci. U.S.A. 86, 4147-4151] even though each G shows similar reactivity [Fuchs, R. P. P. (1984) J. Mel. Biol. 177, 173-180]. Modification at G(4) by the related aromatic amine 2-aminofluorene (AF), which lacks the acetyl group of AAF, can also cause -2 deletions, but at a lower frequency [Bichara, M., and Fuchs, R. P. P. (1985) J. Mol. Biol. 183, 341-351]. A specific mechanism has been proposed to explain the double-base frameshifts in the NarI sequence in which the GC deletion results from a slipped mutagenic intermediate formed during replication [Schaaper, B. M., Koffel-Schwartz, N., and Fuchs, R. P. P. (1990) Carcinogenesis 11, 1087-1095]. We address the following key questions in this study. Why does AAF modification dramatically increase the mutagenicity at the NarI G(4) position, and why does AAF enhance the mutagenicity more than AF? We studied two intermediates which model replication at one arm of a fork, using a fragment of DNA modified by AF or AAF at G(4) in the NarI sequence: [GRAPHICS] Intermediate I can be converted into intermediate II by misalignment. Elongation of intermediate I leads to error-free translesion synthesis, while elongation of intermediate II leads to a -2 frameshift mutation. Minimized potential energy calculations were carried out using the molecular mechanics program DUPLEX to investigate the conformations of the AF and AAF adducts at G(4) in these two intermediates. We find that the slipped mutagenic intermediate is quite stable relative to its normally extended counterpart in the presence of AF and AAF in an abnormal syn orientation of the damaged base. An enhanced probability of elongation from a stable slipped structure rather than a properly aligned one would favor increased -2 frameshift mutations. Furthermore, AAF-modified DNA has a greater tendency to adopt the syn orientation than AF because of its greater bulk, which could explain its greater propensity to cause -2 deletions in the NarI sequence. C1 NYU, Dept Biol, New York, NY 10003 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37830 USA. NYU, Dept Chem, New York, NY 10003 USA. RP Shapiro, R (reprint author), NYU, Dept Biol, New York, NY 10003 USA. FU NCI NIH HHS [CA 28038, CA 75449]; NCRR NIH HHS [RR 06458] NR 88 TC 16 Z9 16 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD NOV PY 1998 VL 11 IS 11 BP 1301 EP 1311 DI 10.1021/tx980106w PG 11 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 140DR UT WOS:000077072000009 PM 9815190 ER PT J AU Jankowiak, R Zamzow, D Stack, DE Todorovic, R Cavalieri, EL Small, GJ AF Jankowiak, R Zamzow, D Stack, DE Todorovic, R Cavalieri, EL Small, GJ TI Spectral characterization of fluorescently labeled catechol estrogen 3,4-quinone-derived N7 guanine adducts and their identification in rat mammary gland tissue SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID POLYACRYLAMIDE-GEL ELECTROPHORESIS; DNA-ADDUCTS; DIOLEPOXIDE; OLIGONUCLEOTIDES; QUINONES; CANCER; N-2-DG AB The oxidation of carcinogenic 4-hydroxycatechol estrogens (CE) of estrone (E-1) and estradiol (E-2) to catechol estrogen 3,4-quinones (CE-3,4-Q) results in electrophilic intermediates that covalently bind to DNA to form depurinating adducts [Cavalieri et al. (1997) Proc. Nail. Acad. Sci. U.S.A. 94, 10937]. These DNA adducts, 4-OHE1-1-N7Gua and 4-OKE2-1-N7Gua, are nonfluorescent. To utilize laser-excited fluorescence methods, the catechol estrogen-derived metabolites and adducts were labeled with a fluorescent marker. The 4-OHEi-1-N7Gua adduct standards (i = 1, 2) and 4-OHEi metabolites have been derivatized with 1-pyrenesulfonyl chloride and investigated by low-temperature spectroscopy under non-line-narrowing and line-narrowing conditions. Molecular modeling studies assisted in interpretation of the fluorescence spectra; energetically favored structures of the 4-OHE2-1-N7Gua-dipyrene adduct and 4-OHE2-dipyrene metabolite reveal unique conformations which, in agreement with fluorescence data, show a significant pi-pi interaction of pyrene labels with guanine and/or the aromatic ring of catechol estrogen. The conformation obtained for the 4-OHE2-1-N7Gua-dipyrene adduct appears to be conducive to mixing of its pi pi* state with pyrene-guanine charge-transfer states, consistent with the experimentally observed strong electron-phonon coupling. Non-line-narrowed and line-narrowed spectra obtained at 77 and 4.2 K, respectively, are shown to distinguish 4-OHE2-1-N7Gua-dipyrene adducts from 4-OHE2-dipyrene metabolites. These standards have subsequently been used for the spectroscopic identification of depurinating DNA adducts formed in a tissue culture experiment where rat mammary gland tissue was treated with the estrogen quinone E-2-3,4-Q. The depurinating adduct formed is 4-OHE2-1-N7Gua. C1 Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. Univ Nebraska, Med Ctr, Canc Res Inst, Omaha, NE 68198 USA. RP Jankowiak, R (reprint author), Iowa State Univ, Ames Lab, USDOE, Ames, IA 50011 USA. EM jankowiak@ameslab.gov FU NCI NIH HHS [CA 49210-05] NR 22 TC 19 Z9 19 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD NOV PY 1998 VL 11 IS 11 BP 1339 EP 1345 DI 10.1021/tx980119+ PG 7 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA 140DR UT WOS:000077072000014 PM 9815195 ER PT J AU Jelinek, R Okada, S Norvez, S Charych, D AF Jelinek, R Okada, S Norvez, S Charych, D TI Interfacial catalysis by phospholipases at conjugated lipid vesicles: colorimetric detection and NMR spectroscopy SO CHEMISTRY & BIOLOGY LA English DT Article DE colorimetric detection; conjugated polymer; enzyme detection; phospholipase; polydiacetylene ID POLYDIACETYLENE THIN-FILMS; GAS WATER INTERFACE; BILAYER-MEMBRANES; MOLECULAR RECOGNITION; BETA-BUNGAROTOXIN; LIPOSOME FUSION; MONOLAYERS; HYDROLYSIS; MODELS; PHOSPHATIDYLCHOLINE AB Background: Self-assembled conjugated polymers are rapidly finding biological and biotechnological applications. This work describes a synthetic membrane system based on self-assembled polydiacetylenes, which are responsive to the enzymatic activity of phospholipases - a ubiquitous class of enzymes that catalyze the hydrolysis of phospholipid molecules embedded in cell membranes. Results: We show that phospholipases are active at bilayer vesicles composed of the natural enzyme substrate, dimyristoylphosphatidylcholine (DMPC), and a synthetic pi-conjugated polymerized lipid based on polydiacetylene (PDA). In addition, the enzymatic reaction induces an optical transition in the surrounding PDA matrix, visible to the naked eye. Nuclear magnetic resonance spectroscopy confirms the occurrence of enzymatic catalysis and reveals the fate of the cleavage products. Conclusions: The results indicate that the structural and color changes of the PDA matrix are directly related to interfacial catalysis by phospholipase. This novel biocatalytic method of inducing optical transitions in conjugated polymers might lead to new approaches towards rapidly screening new enzyme inhibitor compounds. C1 Ben Gurion Univ Negev, Dept Chem, IL-84105 Beer Sheva, Israel. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Ctr Adv Mat, Berkeley, CA 94720 USA. RP Charych, D (reprint author), Chiron Corp, Technol, 4560 Horton Ave,Mailstop 4-5, Emeryville, CA 94608 USA. EM deb_charych@cc.chiron.com RI JELINEK, RAZ/F-2023-2012; OI jelinek, raz/0000-0002-0336-1384 NR 52 TC 54 Z9 55 U1 2 U2 11 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON W1P 6LE, ENGLAND SN 1074-5521 J9 CHEM BIOL JI Chem. Biol. PD NOV PY 1998 VL 5 IS 11 BP 619 EP 629 DI 10.1016/S1074-5521(98)90290-3 PG 11 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA 138PY UT WOS:000076982500005 PM 9831527 ER PT J AU Langlois, DA Benicewicz, BC Douglas, EP AF Langlois, DA Benicewicz, BC Douglas, EP TI Liquid crystalline bispropargyl thermosets SO CHEMISTRY OF MATERIALS LA English DT Article ID ACETYLENE-TERMINATED RESINS; RIGID ROD MOLECULES; INSITU PHOTOPOLYMERIZATION; MESOGENIC DIACRYLATE; CURING REACTIONS; GAS-TRANSPORT; POLYMERIZATION; MONOMERS; POLYMERS; ACRYLATES AB A series of rigid-rod bispropargyl thermoset monomers have been synthesized. These monomers were examined by differential scanning calorimetry (DSC) and hot stage polarized optical microscopy. Enantiotropic or monotropic nematic liquid crystalline phases were observed for all but two monomers. Partial curing of these reactive liquid crystalline monomers resulted in the formation of stable liquid crystalline phases with broad nematic phase ranges. In one example, a monomer that was neither enantiotropic nor monotropic exhibited a stable nematic phase after partial curing. DSC investigations indicated that the onset temperature of thermally induced cross-linking was approximately 260 degrees C and insensitive to the phase type. The rate of cure was insensitive to the phase in which the cure occurred due to the unusual reaction mechanism for the propargyl end group. C1 Univ Calif Los Alamos Natl Lab, Polymers & Coatings Grp, Los Alamos, NM 87545 USA. Univ Florida, Dept Mat Sci & Engn, Gainesville, FL 32611 USA. RP Benicewicz, BC (reprint author), Univ Calif Los Alamos Natl Lab, Polymers & Coatings Grp, POB 1663, Los Alamos, NM 87545 USA. OI Benicewicz, Brian/0000-0003-4130-1232 NR 36 TC 21 Z9 21 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD NOV PY 1998 VL 10 IS 11 BP 3393 EP 3399 DI 10.1021/cm980087b PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 141EG UT WOS:000077129200029 ER PT J AU Woodward, PM Vogt, T Cox, DE Arulraj, A Rao, CNR Karen, P Cheetham, AK AF Woodward, PM Vogt, T Cox, DE Arulraj, A Rao, CNR Karen, P Cheetham, AK TI Influence of cation size on the structural features of Lu(1/2)A(1/2)MuO(3) perovskites at room temperature SO CHEMISTRY OF MATERIALS LA English DT Article ID METAL-INSULATOR-TRANSITION; RARE-EARTH MANGANATES; A-SITE CATIONS; GIANT MAGNETORESISTANCE; NEUTRON-DIFFRACTION; CRYSTAL-STRUCTURE; COLOSSAL MAGNETORESISTANCE; MANGANESE PEROVSKITES; PHASE-TRANSITIONS; MAGNETIC-FIELD AB Polycrystalline samples of Ln(1/2)Sr(1/2)MnO(3) (Ln = La, Pr, La0.33Nd0.67, Nd, Nd0.5Sm0.5, Sm, and Gd) and Ln(1/2)Ca(1/2)MnO(3) (Ln = La, Pr, La0.5Nd0.5, Nd, Sm, and Y0.5Sm0.5) have been prepared, and structure determinations have been carried out at room temperature using high-resolution synchrotron X-ray powder diffraction data. The octahedral tilting distortion increases as the average ionic radius of the Ln/A cations, [rA], decreases. The two crystallographically distinct Mn-O-Mn bonds [Mn-O(eq)-Mn and Mn-O(ax)-Mn] are almost identical for Ln(0.5)Ca(0.5)MnO(3) compounds, with the exception of La0.5Ca0.5MnO3. The La0.5Ca0.5MnO3 compound and the entire Ln(0.5)Sr(0.5)MnO(3) series adopt structures where the Mn-O(eq)-Mn bond angle is consistently and significantly larger (2-6 degrees) than the Mn-O(ax)-Mn bond angle. All of the Ln(0.5)Ca(0.5)MnO(3) compounds have Pnma symmetry, whereas across the Ln(0.5)Sr(0.5)MnO(3) series with increasing (rA), an evolution from Pnma (tilt system a(-)b(+)a(-)) over Imma (tilt system a(-)b(0)a(-)) to I4/mcm (tilt system a(0)a(0)c(-)) symmetry is observed. It appears that the latter two tilt systems are stabilized with respect to the rhombohedral (R (3) over bar c) a(-)a(-)a(-) tilt system, by short-range layered ordering of A-site cations. Changes in the octahedral tilt system at room temperature are linked to changes in the low-temperature magnetic structure. In particular, the simultaneous onset of charge ordering and CE-type antiferromagnetism in the Ln(0.5)Sr(0.5)MnO(3) series appears to be closely associated with the Imma structure. The average Mn-O bond distance is relatively constant across the entire series, but individual Mn-O bond distances show the presence of a cooperative Jahn-Teller effect (orbital ordering) at room temperature in Sm0.5Ca0.5MnO3 and Sm0.25Y0.25Ca0.5MnO3. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Indian Inst Sci, Solid State & Struct Chem Unit, Bangalore 560012, Karnataka, India. Univ Oslo, Dept Chem, N-0315 Oslo, Norway. Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA. RP Ohio State Univ, Dept Chem, 100 W 18Th Ave, Columbus, OH 43210 USA. RI Karen, Pavel/A-9062-2008; Rao, C.N.R./B-1569-2009; Vogt, Thomas /A-1562-2011; Ahirwal, Ashish /F-2532-2013 OI Karen, Pavel/0000-0003-2937-6477; Rao, C.N.R./0000-0003-4088-0615; Vogt, Thomas /0000-0002-4731-2787; Ahirwal, Ashish /0000-0002-9127-6541 NR 78 TC 190 Z9 194 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD NOV PY 1998 VL 10 IS 11 BP 3652 EP 3665 DI 10.1021/cm980397u PG 14 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA 141EG UT WOS:000077129200065 ER PT J AU D'Eath, P Sornborger, A AF D'Eath, P Sornborger, A TI Persistence amplitudes from numerical quantum gravity SO CLASSICAL AND QUANTUM GRAVITY LA English DT Article ID MASSLESS SCALAR FIELD; GRAVITATIONAL COLLAPSE; SUPERGRAVITY AB The Euclidean quantum amplitude to go between data specified on an initial and a final hypersurface may be approximated by the tree amplitude exp(-I-classical/(h) over bar), (1) where I-classical is the Euclidean action of the classical solution joining the initial and final data. In certain cases the tree amplitude is exact. We study I-classical and hence the quantum amplitude, in the case of a spherically symmetric Riemannian gravitational field coupled to a spherically symmetric scalar field. The classical scalar field obeys an elliptic equation, which we solve using relaxation techniques. in conjunction with the field equations giving the gravitational field. An example of the transition from linearity to nonlinearity is presented and power-law behaviour of the action is demonstrated. C1 Univ Cambridge, DAMTP, Cambridge CB3 9EW, England. NASA, Fermi Natl Accelerator Lab, Fermilab Astrophys Grp, Batavia, IL 60510 USA. RP D'Eath, P (reprint author), Univ Cambridge, DAMTP, 3 Silver St, Cambridge CB3 9EW, England. NR 23 TC 4 Z9 4 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0264-9381 J9 CLASSICAL QUANT GRAV JI Class. Quantum Gravity PD NOV PY 1998 VL 15 IS 11 BP 3435 EP 3447 DI 10.1088/0264-9381/15/11/010 PG 13 WC Astronomy & Astrophysics; Physics, Multidisciplinary; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA 141CX UT WOS:000077126000010 ER EF