FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Nagel, LJ Fultz, B Robertson, JL AF Nagel, LJ Fultz, B Robertson, JL TI Phase equilibria of Co3V SO JOURNAL OF PHASE EQUILIBRIA LA English DT Article AB In situ neutron diffraction experiments were performed over a wide range of temperatures on the alloy Co3V. These experiments showed that the L1(2) region of the phase diagram does not exist. The observed Lit phase appears to be a metastable state that can be obtained in quenched alloys. The hP24-fcc phase boundary was estimated to be 1045 degrees C. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Nagel, LJ (reprint author), CALTECH,DEPT MAT SCI,PASADENA,CA 91125, USA. NR 10 TC 11 Z9 11 U1 0 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1054-9714 J9 J PHASE EQUILIB JI J. Phase Equilib. PD FEB PY 1997 VL 18 IS 1 BP 21 EP 23 DI 10.1007/BF02646756 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA WN536 UT WOS:A1997WN53600003 ER PT J AU Smith, AB Schmidt, D AF Smith, AB Schmidt, D TI Neutron scattering and models: Chromium SO JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS LA English DT Article ID OPTICAL-MODEL; INELASTIC-SCATTERING; ELASTIC-SCATTERING; CORE POLARIZATION; NUCLEI AB Neutron elastic-scattering cross sections of elemental chromium are measured from 4.5-10 MeV in steps of approximate to 0.5 MeV and at greater than or similar to 40 scattering angles distributed between 17 degrees and 160 degrees. Concurrently cross sections for the inelastic neutron-excitation of the yrast 2(+) (1.434 MeV) level in Cr-52 are determined. The experimental results are combined with lower-energy values previously reported from this group and with results from the literature to form an extensive scattering database which is interpreted in the context of spherical-optical and coupled-channels models. The physical implications of the measurements and models are discussed including; deformation, coupling, dispersive and asymmetry effects. C1 UNIV ARIZONA,TUCSON,AZ. PHYS TECH BUNDESANSTALT,D-3300 BRAUNSCHWEIG,GERMANY. RP Smith, AB (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 71 TC 6 Z9 6 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0954-3899 J9 J PHYS G NUCL PARTIC JI J. Phys. G-Nucl. Part. Phys. PD FEB PY 1997 VL 23 IS 2 BP 197 EP 209 DI 10.1088/0954-3899/23/2/007 PG 13 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA WJ026 UT WOS:A1997WJ02600007 ER PT J AU Keeney, JA Bass, BR AF Keeney, JA Bass, BR TI Fracture analysis of the NESC-1 spinning cylinder experiment SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference CY JUL 23-27, 1995 CL HONOLULU, HI SP Amer Soc Mech Engineers AB This palter presents finite-element analyses of the cylinder specimen being used in the international Network for Evaluating Steel Components (NESC) large-scale spinning-cylinder project (NESC-1). The objective of the NESC-1 project is to focus on a complete process for assessing the structural integrity of aged reactor pressure vessels. A new cylinder specimen was reconstituted from segments of the previously: tested SC-4 and SC-6 specimens because the relatively high fracture toughness of the original specimen might preclude achieving the test objectives. The wall thickness is greater for the reconstituted specimen when compared with the previous specimen geometry (175 versus 150 mm). Also, the initial and coolant temperatures for the proposed thermal shock may be reduced as much as 25 degrees C to increase the probability of achieving cleavage initiation. Analyses were carried out to determine the combined effects of increasing the wall thickness and lowering the initial and coolant temperatures in the experiment. Estimates were nr ade of the change in hoop strain on the clad inner surface directly above a subclad crack due to initiation and axial propagation of the crack, Three-dimensional ab finite-element models of the cladded cylinder were generated with 6:1 and 2:1 semi-elliptical 70-mm-deep subclad cracks. The cylinder specimen was subjected to thermal-shock and centrifugal loading conditions and analyzed with a thermo-elastic-plastic material model. The analytical results indicate that lowering the initial and coolant temperatures by 25 degrees C will Mot significantly change the peak driving force, but will shift the stress-intensity factor (K-1) versus temperature curves so that the crack will become critical at an earlier time in the transient. The peak KI value occurs at a lower temperature (after the crack becomes critical), which increases the probability of achieving cleavage initiation. Also, the calculated hoop strains Sor the two crack aspect ratios (simulation of 2:1 crack propagating axially) provide an estimated change in hoop strain in the range of 3 to 4 percent on the clad inner surface. RP Keeney, JA (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 5 TC 2 Z9 2 U1 1 U2 1 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD FEB PY 1997 VL 119 IS 1 BP 52 EP 56 DI 10.1115/1.2842266 PG 5 WC Engineering, Mechanical SC Engineering GA WK950 UT WOS:A1997WK95000008 ER PT J AU Simos, N Chassapis, C AF Simos, N Chassapis, C TI Classical versus improved thin shell theories: A theoretical argument or a design concern? SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article AB Differences in the response of thin nonshallow spherical shells resulting from the choice of the adopted shell theory (classical or improved) are addressed analytically and through a series of representative shell problems. The analytical approach utilized to study the variation between the two theoretical models is based on the response resulting from singular lends, The differences are quantified in a set of problems that reflect on the assumptions used in formulating the analytical description of the two theories in question. The broad scope of this paper is to examine the impact of shear deformability, introduced by the improved theory on the stress field when amplified under specific lending and geometric conditions, when those are of primary concern to the engineers. Such cases associated with stress concentration around cutouts, interaction of shells with nozzles, stress field in the vicinity of concentrated sur;face loads, etc. The mathematical formulation is based on the derivation of appropriate Green functions and the computational scheme is formed upon a special type of boundary integral equation., Comparison solutions for stress concentration around circular cutouts of twisted and sheared shells, stress amplification in the junction of shell with nozzles, and local stress field induced by concentrated loads are presented for the two theories. C1 STEVENS INST TECHNOL,DEPT MECH ENGN,HOBOKEN,NJ 07030. RP Simos, N (reprint author), BROOKHAVEN NATL LAB,ASSOCIATED UNIV INC,DEPT ADV TECHNOL,BLDG 197C,POB 5000,UPTON,NY 11973, USA. NR 16 TC 0 Z9 0 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD FEB PY 1997 VL 119 IS 1 BP 96 EP 104 DI 10.1115/1.2842273 PG 9 WC Engineering, Mechanical SC Engineering GA WK950 UT WOS:A1997WK95000015 ER PT J AU Teske, JG Edmonds, CG Deckert, G Satterlee, JD AF Teske, JG Edmonds, CG Deckert, G Satterlee, JD TI Structural features of Glycera dibranchiata monomer hemoglobins. Primary sequences of monomer hemoglobin components II and III SO JOURNAL OF PROTEIN CHEMISTRY LA English DT Article DE Glycera dibranchiata; monomer hemoglobin; primary sequence; mass spectrometry; HPLC; alignments ID AMINO-ACID-SEQUENCE; HYPERFINE RESONANCE ASSIGNMENTS; IONIZATION MASS-SPECTROMETRY; SLOW CYANIDE BINDING; ELECTROSPRAY-IONIZATION; NMR RESONANCES; OXYGEN BINDING; LIGAND-BINDING; HEME-PROTEINS; IV AB Primary sequences for the remaining two members (GMH2, GMH3) of the group of three major monomeric hemoglobins from the marine annelid Glycera dibranchiata have been obtained. Full sequences of each 147-amino acid globin were achieved with a high degree of confidence using standard Edman technology in combination with molecular mass determinations of the intact globins and of the cyanogen bromide cleavage fragments using electrospray ionization mass spectrometry. When minor assumptions concerning Q/E identities are made these new results indicate the likely correspondence of GMG2 with the protein represented by the first Glycera dibranchiata monomer hemoglobin complete sequence [Imamura et al., (1972), J. Biol. Chem. 247, 2785-2797]. When these new sequences are combined with the previously determined primary sequence for the third major monomer hemoglobin, GMH4 [Alam et al., J. Protein Chem. (1994), 13, 151-164], it becomes clear that these three (GMG2-4) are truly distinct proteins, contrary to previous suggestions. Surprisingly, our results show that none of these three primary sequences is identical to the published sequence of the refined monomer hemoglobin crystal structure protein; however, there is a strong correspondence to the GMG2 sequence. The present sequencing results, in combination with the published GMH4 sequence, confirm the presence of a distal Leu in place of the more commonly encountered distal His in all three of the major monomer hemoglobins isolated in this laboratory and indicate that the unusual B10 Phe occurs only in GMH4. Analysis of the sequences presented here, along with comparison of amino acid content for Glycera dibranchiata monomer hemoglobins isolated from three different laboratories, and comparison of NMR results from two laboratories suggest further correspondences which unify disparate published isolations. C1 WASHINGTON STATE UNIV, DEPT CHEM, PULLMAN, WA 99164 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. FU NIGMS NIH HHS [GM47423, GM47645] NR 34 TC 8 Z9 8 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0277-8033 J9 J PROTEIN CHEM JI J. Protein Chem. PD FEB PY 1997 VL 16 IS 2 BP 139 EP 150 DI 10.1023/A:1026346202134 PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WT459 UT WOS:A1997WT45900007 PM 9112607 ER PT J AU Wu, D Landsberger, S Vandegrift, GF AF Wu, D Landsberger, S Vandegrift, GF TI Application of neutron activation analysis in a fission molybdenum separation study SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT 9th International Conference on Modern Trends in Activation Analysis (MTAA-9) CY SEP 24-30, 1995 CL SEOUL, SOUTH KOREA SP Korea Inst Geol Min & Mat, Int Atom Energy Agcy, Korean Soc Anal Sci AB The separation of Mo-99 from low-enriched uranium (LEU, 19.5% U-235) targets was evaluated using natural uranium (NU) and non-radioactive tracers. Neutron activation analysis was used to determine (1) the efficiency of molybdenum recovery and (2) the decontamination factor of numerous fission product elements from the molybdenum product. Using NU and non-radioactive elements simplified procedures and allowed tests to be completed in a fume hood instead of a shielded cell. During activation of the non-radioactive tracers, uranium fission occurs, which can interfere with subsequent gamma-ray analysis. A comparison was made of the interferences caused by these fission products from both NU and LEU. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. RP Wu, D (reprint author), UNIV ILLINOIS,DEPT NUCL ENGN,214 NEL,103 S GOODWIN AVE,URBANA,IL 61801, USA. NR 13 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD FEB PY 1997 VL 216 IS 1 BP 101 EP 105 DI 10.1007/BF02034503 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV467 UT WOS:A1997XV46700018 ER PT J AU Palmer, DA Wesolowski, DJ AF Palmer, DA Wesolowski, DJ TI Potentiometric measurements of the first hydrolysis quotient of magnesium(II) to 250 degrees C and 5 molal ionic strength (NaCl) SO JOURNAL OF SOLUTION CHEMISTRY LA English DT Article DE magnesium; hydrolysis; potentiometry; thermodynamics; aqueous; temperature; ionic strength ID SODIUM-CHLORIDE MEDIA; AQUEOUS-SOLUTIONS; WATER; ELECTROLYTES; THERMODYNAMICS; 300-DEGREES-C; TEMPERATURES; IONIZATION; PARAMETERS; PRESSURES AB The first molal hydrolysis quotient, Q(1,1), of Mg2+ was measured potentiometrically from 1 to 250 degrees C at ionic strengths of 0.11, 0.31, 1.01, and 5.0 mol-kg(-1) in an aqueous NaCl medium using a hydrogen-electrode, concentration cell. Only hydrolysis of the first four percent of the magnesium in solution could be followed before precipitation of brucite, Mg(OH)(2)(cr), occurred. The log Q(1,1) values were fitted as a function of temperature and ionic strength using four adjustable parameters. The resulting constants are compared with the limited existing low temperature data. At infinite dilution and 25 degrees C the following quantities are reported: log K-1,K-1 = -11.68+/-0.05, Delta H degrees = 70.1+/-1.2 kJ-mol(-1), Delta H degrees = 11+/-4 J-K-1-mol(-1), and Delta C-p(o) = 0 J-K-1-mol(-1). At each ionic strength, including the values extrapolated to infinite dilution, the heat capacity change for the hydrolysis reaction was zero, i.e., log Q(1,1) was found to be a linear function of the reciprocal temperature in Kelvin, at least over the measured range of 1-250 degrees C. The hydrolysis constants at infinite dilution were modeled to 550 degrees C and two kbar pressure with a function incorporating solvent density using published results obtained at these extreme conditions. RP Palmer, DA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,BLDG 4500S,POB 2008,OAK RIDGE,TN 37831, USA. NR 28 TC 24 Z9 24 U1 2 U2 9 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0095-9782 J9 J SOLUTION CHEM JI J. Solut. Chem. PD FEB PY 1997 VL 26 IS 2 BP 217 EP 232 DI 10.1007/BF02767923 PG 16 WC Chemistry, Physical SC Chemistry GA WU766 UT WOS:A1997WU76600008 ER PT J AU Crevel, G Huikeshoven, H Cotterill, S Simon, M Wall, J Philpott, A Laskey, RA McConnell, M Fisher, PA Berrios, M AF Crevel, G Huikeshoven, H Cotterill, S Simon, M Wall, J Philpott, A Laskey, RA McConnell, M Fisher, PA Berrios, M TI Molecular and cellular characterization of CRP1, a Drosophila chromatin decondensation protein SO JOURNAL OF STRUCTURAL BIOLOGY LA English DT Article ID NUCLEAR LAMIN ISOFORMS; XENOPUS EGG EXTRACTS; HEAT-SHOCK; DEVELOPMENTAL REGULATION; AFFINITY PURIFICATION; SPERM DECONDENSATION; NUCLEOLAR PROTEIN; EUKARYOTIC CELLS; DNA-REPLICATION; FREE SYSTEM AB CRP1, a Drosophila nuclear protein that can catalyze decondensation of demembranated Xenopus sperm chromatin was cloned and its primary structure was deduced from cDNA sequence, Alignment of deduced amino acid sequence with published sequences of other proteins revealed strong homologies to Xenopus nucleoplasmin and NO38, CRP1 is encoded by one or several closely related genes found at a single locus, position 99A on the right arm of chromosome 3, CRP1 mRNA is expressed throughout Drosophila development; it is highest during oogenesis and early embryogenesis. mRNA levels correlate closely with levels of protein expression measured previously, Results of chemical crosslinking indicate that CRP1 is either tetrameric off pentameric; similar ambiguity was revealed by direct visualization using scanning transmission electron microscopy. Consistent with previously published results, parallel crosslinking studies of Xenopus nucleoplasmin suggested a pentameric structure. Scanning transmission electron microscopic examination after negative staining revealed that CRP1 and Xenopus nucleoplasmin are morphologically similar. CRP1 is able to substitute for nucleoplasmin in Xenopus egg extract-mediated sperm chromatin decondensation. In vitro, CRP1-induced decondensation is accompanied by direct binding of CRP1 to chromatin. (C) 1997 Academic Press. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. WELLCOME CRC INST,CAMBRIDGE CB2 1QR,ENGLAND. SUNY STONY BROOK,DEPT PHARMACOL SCI,MED CTR,STONY BROOK,NY 11794. RP Crevel, G (reprint author), MARIE CURIE RES INST,OXTED RH8 0TL,SURREY,ENGLAND. FU NCRR NIH HHS [P41-RR01777]; Wellcome Trust NR 45 TC 36 Z9 37 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 1047-8477 J9 J STRUCT BIOL JI J. Struct. Biol. PD FEB PY 1997 VL 118 IS 1 BP 9 EP 22 DI 10.1006/jsbi.1996.3836 PG 14 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WN413 UT WOS:A1997WN41300002 PM 9087911 ER PT J AU Moss, WC AF Moss, WC TI Understanding the periodic driving pressure in the Rayleigh-Plesset equation SO JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA LA English DT Letter AB The Rayleigh-Plesset equation is the basis of most theoretical analyses of bubble dynamics. Surprisingly, experiment and theory do not agree on the spatial location and the value of the periodic driving pressure. In the experiment the driving pressure is located near the bubble, whereas, the theory assumes that the driving pressure is far from the bubble. The paradox is resolved by deriving a modified equation that is valid for compressible flows in a finite spherical geometry. The modified equation is identical to the incompressible Rayleigh-Plesset equation with the driving pressure at infinity replaced by the actual driving pressure, which is located within 25 bubble radii of the bubble. We show that a hydrophone at the center of the flask measures this driving pressure, which is why the theory and experiment agree when an incompressible Rayleigh-Plesset equation is used to describe compressible flows. (C) 1997 Acoustical Society of America. RP Moss, WC (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 13 TC 13 Z9 13 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0001-4966 J9 J ACOUST SOC AM JI J. Acoust. Soc. Am. PD FEB PY 1997 VL 101 IS 2 BP 1187 EP 1190 DI 10.1121/1.418111 PG 4 WC Acoustics; Audiology & Speech-Language Pathology SC Acoustics; Audiology & Speech-Language Pathology GA WH323 UT WOS:A1997WH32300056 ER PT J AU Laulainen, N Trexler, E AF Laulainen, N Trexler, E TI Assessing the relative contribution of biogenic and fossil processes to visibility-scattering aerosols found in remote areas: Near-term organic research program SO JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION LA English DT Article; Proceedings Paper CT Aerosols and Atmospheric Optics: Radiative Balance and Visual Air Quality Conference CY SEP 26-30, 1994 CL SNOWBIRD, UT SP Air & Waste Management Assoc, Amer Geophys Union ID HUMIDITY AB Organic carbon has been found to be a significant component of aerosols that impair visibility in remote areas across the country. Organic aerosols are particularly important in western areas of the United States and contribute roughly equally with sulfate aerosols and dust in the total extinction budget. Potential visibility enhancement resulting from various future energy management options that reduce volatile organic carbon and particulate material emissions from fossil-energy-related processes hinges on the relative contribution of the fossil-fuel-derived;organic component to the extinction budget. Thus, additional studies are needed to quantify the partitioning of organic carbon between biogenic and fossil sources. Relative humidity (RH) also plays an important role in visibility impairment. It is well known that water soluble aerosol species, such as sulfate and nitrate, can increase light-scattering efficiencies of fine particles by more than an order of magnitude as RH is increased from 20-30% to 90-95%. Organic carbon aerosol has been found to be a mixture of more soluble and less soluble components, but few studies have been performed to evaluate the RH: response function of aerosols composed of these components, either separately or in combination, especially at high relative humidities. The purpose of this paper is to describe some experiments that could address the major uncertainties of biogenic and fossil carbon contributions to the fine particle extinction budget and visibility impairment. C1 US DOE, WASHINGTON, DC USA. RP Laulainen, N (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU AIR & WASTE MANAGEMENT ASSOC PI PITTSBURGH PA ONE GATEWAY CENTER, THIRD FL, PITTSBURGH, PA 15222 SN 1047-3289 J9 J AIR WASTE MANAGE JI J. Air Waste Manage. Assoc. PD FEB PY 1997 VL 47 IS 2 BP 212 EP 215 PG 4 WC Engineering, Environmental; Environmental Sciences; Meteorology & Atmospheric Sciences SC Engineering; Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WJ729 UT WOS:A1997WJ72900012 ER PT J AU Hwang, SL Becher, PF Lin, HT AF Hwang, SL Becher, PF Lin, HT TI Desintering process in the gas-pressure sintering of silicon nitride SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID FRACTURE-TOUGHNESS; SI3N4; POWDER; OXYGEN; DENSIFICATION; CERAMICS AB A unique desintering phenomenon has been observed in gas-pressure sintering of silicon nitrides with additives of yttria and alumina, The desintering phenomenon occurred, simultaneous with weight increase, only when a boron nitride crucible was used in combination with the application of high nitrogen pressure (5 MPa), When the nitrogen pressure was low (0.5 MPa), or when the boron nitride crucible was replaced by a graphite crucible, this desintering phenomenon was not observed, These results could be rationalized by the chemical dissolution of nitrogen into the oxynitride melts and the resultant evolution of carbon monoxide, This indicates that the high nitrogen overpressure employed in gas-pressure sintering of silicon nitride ceramics is not always beneficial. RP Hwang, SL (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37830, USA. NR 29 TC 16 Z9 16 U1 0 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1997 VL 80 IS 2 BP 329 EP 335 PG 7 WC Materials Science, Ceramics SC Materials Science GA WK085 UT WOS:A1997WK08500008 ER PT J AU Wallis, DJ Browning, ND Nellist, PD Pennycook, SJ Majid, I Liu, Y VanderSande, JB AF Wallis, DJ Browning, ND Nellist, PD Pennycook, SJ Majid, I Liu, Y VanderSande, JB TI Atomic structure of a 36.8 (210) tilt grain boundary in TiO2 SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID ELECTRON-ENERGY-LOSS; MULTIPLET STRUCTURE; LOSS SPECTROSCOPY; VACANCY LEVELS; CRYSTALS AB An understanding of the atomic structure at internal interfaces is of crucial importance for the electronic and structural properties of most advanced materials. Here, me present a detailed study of the atomic structure at a [001] tilt grain boundary of Sigma 5(210) in TiO2 (rutile). Z-contrast imaging is used to obtain a 2-D atomic map of the cation positions at the interface. Details of the charge state of cations and atomic structure around anion sites are then provided using electron energy loss spectroscopy, In particular, the spectroscopic data for oxygen is interpreted using multiple scattering theory to give 3-D structural information. These combined techniques allow a unique grain boundary structure to be defined. C1 OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. MIT, DEPT MAT SCI & ENGN, CAMBRIDGE, MA 02139 USA. RP Wallis, DJ (reprint author), UNIV ILLINOIS, DEPT PHYS, CHICAGO, IL 60607 USA. OI Browning, Nigel/0000-0003-0491-251X NR 24 TC 23 Z9 24 U1 0 U2 4 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD FEB PY 1997 VL 80 IS 2 BP 499 EP 502 PG 4 WC Materials Science, Ceramics SC Materials Science GA WK085 UT WOS:A1997WK08500031 ER PT J AU Superko, HR Krauss, RM AF Superko, HR Krauss, RM TI LDL subclass distribution change in familial combined hyperlipidemia patients following gemfibrozil and niacin treatment SO JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. BERKELEY HEARTLAB,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0735-1097 J9 J AM COLL CARDIOL JI J. Am. Coll. Cardiol. PD FEB PY 1997 VL 29 IS 2 SU A BP 92191 EP 92191 PG 1 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA WF761 UT WOS:A1997WF76100182 ER PT J AU Weinberger, J Mirzadeh, S Knapp, FFR Amols, H AF Weinberger, J Mirzadeh, S Knapp, FFR Amols, H TI Beta irradiation for restenosis after stent transplantation: Dose variations among differing stents SO JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. COLUMBIA UNIV,NEW YORK,NY 10027. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0735-1097 J9 J AM COLL CARDIOL JI J. Am. Coll. Cardiol. PD FEB PY 1997 VL 29 IS 2 SU A BP 97359 EP 97359 PG 1 WC Cardiac & Cardiovascular Systems SC Cardiovascular System & Cardiology GA WF761 UT WOS:A1997WF76101005 ER PT J AU McLuckey, SA Stephenson, JL OHair, RAJ AF McLuckey, SA Stephenson, JL OHair, RAJ TI Decompositions of odd- and even-electron anions derived from deoxy-polyadenylates SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID CHARGED OLIGONUCLEOTIDE ANIONS; GAS-PHASE; MASS-SPECTROMETRY; ION TRAP AB Radical anions have been formed via electron transfer from multiply charged 5'-d(AAA)-3' and 5'-d(AAAA)-3' anions to CCl3+. These ions have been isolated in a quadrupole ion trap operated with helium bath gas at a pressure of 1 mtorr and subjected to resonance excitation (i.e., conventional ion trap collisional activation). Collisional activation of the even-electron species of the same charge state formed directly via electrospray was also performed by using essentially identical conditions. The collisional activation data can be compared directly without ambiguity arising from differences in parent ion internal energies and/or dissociation time frames. Both the odd- and even-electron anions yield extensive sequence-informative fragmentation but show significant differences in the extent of nucleobase loss and in the relative contributions from the various sequence diagnostic dissociation channels. The results of this study indicate that radical anions derived from multiply deprotonated oligo-deoxynucleotides that survive the electron transfer process are stable with respect to fragmentation in the ion trap environment under normal storage conditions and that the unimolecular dissociation behavior of these ions differs from the even-electron anions of the same charge state. These findings suggest, therefore, that odd- and even-electron anions might be used to provide complementary sequence information in cases in which neither ion type provides the full sequence. (C) 1997 American Society for Mass Spectrometry C1 UNIV MELBOURNE,SCH CHEM,PARKVILLE,VIC 3052,AUSTRALIA. RP McLuckey, SA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 17 TC 44 Z9 44 U1 0 U2 5 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD FEB PY 1997 VL 8 IS 2 BP 148 EP 154 DI 10.1016/S1044-0305(96)00231-0 PG 7 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA WF079 UT WOS:A1997WF07900006 ER PT J AU Jacomino, VMF Fields, DE AF Jacomino, VMF Fields, DE TI A critical approach to the calibration of a watershed model SO JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION LA English DT Article DE simulation; modeling/statistics; watershed management; hydrology; optimization; sensitivity analysis ID SENSITIVITY ANALYSIS; HYDROLOGY; UNCERTAINTY AB A complex watershed-scale water quality simulation model, the Hydrological Simulation Program-FORTRAN (HSPF) model, was calibrated for a 16 km(2) catchment. The simulation step size was 0.33 hours with predicted and recorded hydrologic flows compared on an annual and monthly basis during a total calibration period of four years. Unguided numerical optimization when applied alone did not yield a model parameter set with acceptable predictive capability; instead, it was necessary to apply a critical process that included sensitivity analysis, numerical optimization, and testing of derived model parameter sets to evaluate their performance for periods other than those for which they were determined. Using this critical calibration process, the model was proven to have significant predictive capability Numerical optimization is an aid for model calibration, but it must not be used blindly. C1 OAK RIDGE NATL LAB, KNOXVILLE, TN 37931 USA. RP Jacomino, VMF (reprint author), IPEN CNEN SP, CAIXA POSTAL 11040, BR-05422970 SAO PAULO, BRAZIL. NR 13 TC 27 Z9 28 U1 1 U2 9 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 1093-474X J9 J AM WATER RESOUR AS JI J. Am. Water Resour. Assoc. PD FEB PY 1997 VL 33 IS 1 BP 143 EP 154 DI 10.1111/j.1752-1688.1997.tb04091.x PG 12 WC Engineering, Environmental; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA WX810 UT WOS:A1997WX81000016 ER PT J AU Kostecki, R McLarnon, F AF Kostecki, R McLarnon, F TI Electrochemical and in situ Raman spectroscopic characterization of nickel hydroxide electrodes SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID QUARTZ CRYSTAL MICROBALANCE; ATOMIC-FORCE MICROSCOPY; OXIDE ELECTRODES; ELECTROCHROMIC BEHAVIOR; FILMS; IDENTIFICATION; STATE; IRON AB In situ laser Raman spectra of electrochemically precipitated thin-film Ni(OH)(2) electrodes in alkaline NaOH electrolytes were recorded, and the effect of repeated charge-discharge cycling on the structure and phase composition of the discharged and charged films was investigated. Careful deconvolution analyses of the Raman and surface-enhanced Raman spectra showed that freshly precipitated films of Ni(OH)(2) contain not only an oc-like phase but also small amounts of a beta-phase. By combining cyclic voltammetry with in situ Raman spectroscopy, spectral changes that accompanied charge-discharge cycling could be associated with a partial transformation of the predominant alpha-phase into a disordered beta-Ni(OH)(2) phase. A new phase characterized by a vibration at 522 cm(-1) was also discovered in the film at the end of the cycling procedure. Analysis of the Raman spectra of the oxidized electrode (NiOOH active material) revealed for the first time a slight variation of the 477/559 cm(-1) peak pair ratio, which corresponds to phase transitions in the Ni(III) hydrous -1 oxide film, as the electrode was cycled. Significant differences between the low-frequency-region Raman spectra of chemically synthesized alpha,beta-Ni(OH)(2) and those of highly disordered hydrous Ni(OH)(2) films, as well as the absence of characteristic vibrations in the OK stretching region of the in situ Raman spectra of the Ni(OH)(2) electrode, suggest that chemically prepared alpha,beta-nickel hydroxides should not be regarded as structural models for electrochemically precipitated thin-film materials. RP Kostecki, R (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720, USA. NR 28 TC 81 Z9 81 U1 5 U2 37 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1997 VL 144 IS 2 BP 485 EP 493 DI 10.1149/1.1837437 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WL647 UT WOS:A1997WL64700021 ER PT J AU Yu, XH Bates, JB Jellison, GE Hart, FX AF Yu, XH Bates, JB Jellison, GE Hart, FX TI A stable thin-film lithium electrolyte: Lithium phosphorus oxynitride SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID IONIC CONDUCTIVITIES; POLYMER ELECTROLYTE; INTERFACE; ELLIPSOMETRY; BATTERIES; GLASSES AB The electrochemical and optical properties of Lithium phosphorous oxynitride (Lipon) thin films have been studied with an emphasis on the stability window vs. lithium metal and the behavior of the Li/Lipon interface. Impedance measurements made between -26 and 140 degrees C show that Lipon exhibits a single, Li+-ion conducting phase with an average conductivity of 2.3 (+/-0.7) x 10(-6) S/cm at 25 degrees C and an average activation energy of E(a) = 0.55 +/- 0.02 eV. No detectable reaction or degradation was evident at the Li/Lipon interface, and linear sweep voltammetry measurements on three-electrode cells indicated that Lipon is stable from 0 to about 5.5 V with respect to a Li+/Li reference. The complex refractive index of Lipon was measured by spectroscopic ellipsometry. Optical bandgaps of 3.45 and 3.75 eV were obtained from the ellipsometry data and from optical absorption measurements, respectively. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV SOUTH,DEPT PHYS,SEWANEE,TN 37375. NR 26 TC 354 Z9 365 U1 41 U2 262 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1997 VL 144 IS 2 BP 524 EP 532 DI 10.1149/1.1837443 PG 9 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WL647 UT WOS:A1997WL64700027 ER PT J AU Kane, WF Cohen, SA Hummel, JP Luther, B Beach, DB AF Kane, WF Cohen, SA Hummel, JP Luther, B Beach, DB TI Use of SiBN and SiBON films prepared by plasma enhanced chemical vapor deposition from borazine as interconnection dielectrics SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article ID SILICON DIOXIDE; COPPER; METALLIZATION; DIFFUSION; BARRIERS; TEOS AB Thin films of silicon boron nitride (SiBN) of typical composition Si0.09B0.39N0.51 and silicon boron oxynitride (SiBON) of typical composition Si0.16B0.29O0.41N0.14 were prepared by plasma enhanced chemical vapor deposition and the properties of these films were evaluated with respect to their suitability as interconnection dielectrics in microelectronic fabrication. Films were deposited on 125 mm silicon substrates in a parallel-plate reactor at a substrate temperature of 400 degrees C and a plasma power of 0.5 W/cm(2). Boron nitride, for comparison of electrical properties, was deposited from borazine (B3N3H6); silicon boron nitride was deposited from borazine, disilane (Si2H6), and ammonia (NH3); silicon boron oxynitride was deposited from borazine, disilane, ammonia, and nitrous oxide (N2O). Metal-insulator-metal capacitors were fabricated and electrical measurements indicated that all three films had excellent dielectric proper-ties with dielectric constants of 4.1, 4.7, and 3.9 for BN, SiBN, and SiBON, respectively. Tests of conformality indicated that deposition into trenches with an aspect ratio of 4:1 gave conformality greater than 70%. Silicon boron oxynitride was shown to be an excellent barrier to the diffusion of copper. A planar, single level metal-insulator structure was constructed using a SiBN/SiBON insulator with copper metallization. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Kane, WF (reprint author), IBM CORP,DIV RES,TJ WATSON RES CTR,YORKTOWN HTS,NY 10598, USA. NR 16 TC 14 Z9 15 U1 0 U2 8 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1997 VL 144 IS 2 BP 658 EP 663 DI 10.1149/1.1837463 PG 6 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WL647 UT WOS:A1997WL64700047 ER PT J AU Bondar, VD Grytsiv, MY Groodzinsky, AS Vasyliv, MY Chakhovskoi, AG Hunt, CE Malinowski, ME Felter, TE AF Bondar, VD Grytsiv, MY Groodzinsky, AS Vasyliv, MY Chakhovskoi, AG Hunt, CE Malinowski, ME Felter, TE TI Thin film energy-controlled variable color cathodoluminescent screens SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Article AB A new technique for obtaining energy-variable multicolor cathodoluminescent display screens is presented. This technique employs radio frequency ion plasma sputtering of one thin-film phosphor material over a dissimilar phosphor substrate. The technique employed differs from the old ''Penetron'' screen in that the substrate and the secondary phosphor layer are single-crystal materials. This results in higher resolution and allows the use of lower energy beam excitation. The experiments presented use Y2O3:Eu (red) deposited on a Y3Al5O12-Tb,Ce (green) substrate with excitation in the low killovolt range. The method demonstrated, however, is extendable to a full red-green-blue triplet composed of a wide variety of materials. The screens are particularly applicable to small, low-power formats, such as avionics and instrumentation displays. C1 UNIV CALIF DAVIS,DEPT ELECT & COMP ENGN,DAVIS,CA 95616. SANDIA NATL LABS,LIVERMORE,CA 94550. RP Bondar, VD (reprint author), LVOV IVAN FRANKO STATE UNIV,DEPT PHYS,UA-290005 LVOV,UKRAINE. NR 4 TC 8 Z9 8 U1 0 U2 1 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1997 VL 144 IS 2 BP 704 EP 707 DI 10.1149/1.1837472 PG 4 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WL647 UT WOS:A1997WL64700056 ER PT J AU Doeff, MM Ferry, A Ma, YP Ding, L DeJonghe, LC AF Doeff, MM Ferry, A Ma, YP Ding, L DeJonghe, LC TI Effect of electrolyte composition on the performance of sodium/polymer cells SO JOURNAL OF THE ELECTROCHEMICAL SOCIETY LA English DT Letter ID TRANSFERENCE NUMBER; POLYMER; SODIUM; BATTERIES AB The dependence on Na/P(EO)(n)NaX/NaxMnO2 (P(EO)=poly(ethylene oxide), X=CF3SO3 or (CF3SO2)(2)N)) cell cycle life and rate capability on polymer electrolyte composition is described. Transition time experiments and mathematical modeling indicate that failure due to salt precipitation occurs at it(1/2)=10.5 to 21.4 mA s(0.5)/cm(2), when high initial concentrations of NaCF3SO3 are used in operating cells. Evidence for large ionic clusters in concentrated PEO/NaCF3SO3 solutions is also seen in the Raman spectroscopic data. Salt precipitation is a direct consequence of the concentration gradients that arise during operation, due to the negative cationic transference numbers (t(t)(0)) of the binary saltipolymer electrolyte. By decreasing the initial salt concentration, t(+)(0) is increased, cell rate capability is doubled, and the cycle life is enhanced nearly threefold. Similar improvements are obtained when PEO/NaN(CF3SO2)(2) electrolytes are used. C1 UMEA UNIV,DEPT EXPT PHYS,S-90187 UMEA,SWEDEN. RP Doeff, MM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Doeff, Marca/G-6722-2013 OI Doeff, Marca/0000-0002-2148-8047 NR 19 TC 28 Z9 28 U1 0 U2 12 PU ELECTROCHEMICAL SOC INC PI PENNINGTON PA 10 SOUTH MAIN STREET, PENNINGTON, NJ 08534 SN 0013-4651 J9 J ELECTROCHEM SOC JI J. Electrochem. Soc. PD FEB PY 1997 VL 144 IS 2 BP L20 EP L22 DI 10.1149/1.1837419 PG 3 WC Electrochemistry; Materials Science, Coatings & Films SC Electrochemistry; Materials Science GA WL647 UT WOS:A1997WL64700003 ER PT J AU Bolton, PR Ritchie, B AF Bolton, PR Ritchie, B TI Propagation of intense, ultrashort laser pulses through preionized plasma slabs SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID IONIZATION; RECOMBINATION; ACCELERATION AB Relativistic self-focusing and channel formation induced by intense, ultrashort laser pulses in preionized targets is modeled for accessible experimental parameters. The stability of channel formation is limited by the nonparaxiality of the laser beam in regions of tight self-focusing. This issue is examined with recently developed nonparaxial theory. Channel formation is also characterized in terms of the transmitted pulse spectrum, the transmitted laser intensity profile, and the radial electron density distribution. Calculations indicate a signature spectral shift in transmission biased toward longer wavelengths, which is attributed to the rapid expulsion of electrons away from the propagation axis. RP Bolton, PR (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 21 TC 3 Z9 3 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD FEB PY 1997 VL 14 IS 2 BP 437 EP 443 DI 10.1364/JOSAB.14.000437 PG 7 WC Optics SC Optics GA WH671 UT WOS:A1997WH67100027 ER PT J AU Armstrong, DJ Alford, WJ Raymond, TD Smith, AV Bowers, MS AF Armstrong, DJ Alford, WJ Raymond, TD Smith, AV Bowers, MS TI Parametric amplification and oscillation with walkoff-compensating crystals SO JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS LA English DT Article ID SUM-FREQUENCY; GENERATION; CAVITY; SINGLE AB We measure and model parametric gain and oscillation for two crystals arranged for walkoff compensation. We show how the orientation of the crystals determines the relative sign of the nonlinear mixing coefficient in the two crystals. This sign dramatically influences small signal gain and oscillator performance, and we show how to determine the correct crystal orientation from parametric-gain measurements. The performance of two-crystal oscillators is examined with particular attention to beam tilts, conversion efficiency, and beam quality. We find reduced efficiency and increased oscillation threshold when the coefficients have opposite signs in a two-crystal ring oscillator. Sign reversal seems to have little influence on spectral purity or far-field beam profiles when the oscillator is seeded. (C) 1997 Optical Society of America. C1 ACULIGHT CORP,BELLEVUE,WA 98005. RP Armstrong, DJ (reprint author), SANDIA NATL LABS,DEPT LASERS OPT & REMOTE SENSING,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 22 TC 70 Z9 74 U1 1 U2 10 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0740-3224 J9 J OPT SOC AM B JI J. Opt. Soc. Am. B-Opt. Phys. PD FEB PY 1997 VL 14 IS 2 BP 460 EP 474 DI 10.1364/JOSAB.14.000460 PG 15 WC Optics SC Optics GA WH671 UT WOS:A1997WH67100031 ER PT J AU Wunderlich, B AF Wunderlich, B TI Modeling the heat flow and heat capacity of modulated differential scanning calorimetry SO JOURNAL OF THERMAL ANALYSIS LA English DT Article DE calorimetry; Fourier series; heat capacity; heat flow calorimeter; MDSC; spread-sheet analysis; temperature modulated calorimetry ID TEMPERATURE; DSC AB Modulated differential scanning calorimetry (MDSC) uses an abbreviated Fourier transformation for the data analysis and separation of the reversing component of the heat flow and temperature signals. In this paper a simple spread-sheet analysis will be presented that can be used to better understand and explore the effects observed in MDSC and their link to actual changes in the instrument and sample. The analysis assumes that instrument lags and other kinetic effects are either avoided or corrected for. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Wunderlich, B (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 13 TC 55 Z9 55 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0368-4466 J9 J THERM ANAL JI J. Therm. Anal. PD FEB PY 1997 VL 48 IS 2 BP 207 EP 224 DI 10.1007/BF01979265 PG 18 WC Thermodynamics; Chemistry, Analytical; Chemistry, Physical SC Thermodynamics; Chemistry GA WK782 UT WOS:A1997WK78200001 ER PT J AU Civetta, L Orsi, G Pappalardo, L Fisher, RV Heiken, G Ort, M AF Civetta, L Orsi, G Pappalardo, L Fisher, RV Heiken, G Ort, M TI Geochemical zoning, mingling, eruptive dynamics and depositional processes - The Campanian Ignimbrite, Campi Flegrei caldera, Italy SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article DE calderas; campanian Ignimbrite; Campi Flegrei caldera; chemostratigraphy; large-volume magma chamber; magma mingling; eruptive dynamics ID NEAPOLITAN-YELLOW-TUFF; SIERRA-LA-PRIMAVERA; MAGMA CHAMBER; FRACTIONAL CRYSTALLIZATION; PHLEGRAEAN FIELDS; TRACE-ELEMENT; STRUCTURAL EVOLUTION; CHEMICAL EVOLUTION; PHLEGREAN-FIELDS; ALKALINE MAGMA AB The Campanian Ignimbrite (CI) is a large-volume trachytic tuff erupted at 37 ka from the Campi Flegrei and composed of a fallout deposit overlain by ignimbrite. The ignimbrite was spread over an area of about 30,000 km(2) including the Campanian Plain and the Apennine Mountains, with ridges over 1000 m a.s.l. The pumice fragments of the CI range in composition from trachyte to phonolitic-trachyte (DI = 75-90), They do not show any systematic compositional variation with stratigraphic height, but the analyzed sections can be divided into three groups on the basis of chemical composition of pumices. Least-evolved pumices (DI = 75-83) occur in the ignimbrite in the central sector of the Campanian Plain up to 30 km from the vent, while the most-differentiated pumices (DI = 88-90) characterize the cogenetic fallout deposit and the ignimbrite in the western sector of the Campanian Plain, on the Tyrrhenian scarp of the Apennines between Caserta and Mt. Maggiore, on Roccamonfina volcano, and on the Sorrento Peninsula, up to 50 km from the source. Pumice fragments of intermediate composition (DI = 84-87) occur in the ignimbrite on the Apennine Mountains and Roccamonfina volcano, up to 65 km from the vent. In one exposure at Mondragone, at the base of a calcareous ridge, an ignimbrite with pumices of most-evolved composition is overlain by an ignimbrite with pumices of intermediate composition. The observed compositional variation between most- and least-evolved ignimbrite was generated in part by crystal-liquid fractionation, although other magmatic processes such as syn-eruptive mingling between most- and least-evolved magmas accounts for the mineralogical disequilibria and for the bimodality of the glass compositions in the intermediate-composition rocks. Pumice Sr-isotope ratios are positively correlated with degree of differentiation. Feldspar crystals separated from pumices of different compositions have a homogeneous Sr-isotope composition similar to that of the least-evolved pumices. Interaction between fluids and strongly fractionated Sr-poor less-dense magma can account for these isotopic features. Geochemical, mineralogic, stratigraphic and volcanologic data, together with the stratigraphic relations between most-, intermediate- and least-evolved ignimbrite as detected at Mondragone and from bore-hole drillings suggest that: (1) the CI magmatic system was composed of two distinct magma layers - the upper layer was more differentiated and homogeneous in composition, while the deeper was less evolved and slightly zoned; and (2) the CI was mostly emplaced in three main pulses of pyroclastic flows that tapped the chamber at variable levels and with distinct withdrawal dynamics. The eruption began with emission of the most differentiated magma, which gave rise to the fallout deposit. It continued with generation of expanded, turbulent pyroclastic flows that reached the Sorrento Peninsula in the southeast and Roccamonfina volcano in the northwest. These flows, whose thickness was greater than the overtopped relief, were able to travel over the water of the bay of Naples. Subsequently an intermediate-composition magma resulting from mingling of different portions of the magma chamber generated similar flows that spread radially and traveled not less than 65 km from the vent. During the last pulse the least-evolved magma was tapped and generated flows that spread within the Campanian Plain. Variation in eruptive dynamics and composition of magma during the course of the eruption likely reflected variations of both geometry of vent and plumbing system, and efficiency of water/magma interaction, which in turns affected the dynamics of the magma chamber and the withdrawal mechanism, and resulted from the dynamics of the caldera collapse. C1 OSSERV VESUVIANO,NAPLES,ITALY. UNIV CALIF SANTA BARBARA,DEPT GEOL SCI,SANTA BARBARA,CA 93106. LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. NO ARIZONA UNIV,DEPT GEOL & ENVIRONM SCI,FLAGSTAFF,AZ 86011. RP Civetta, L (reprint author), UNIV NAPLES FEDERICO II,DIPARTIMENTO GEOFIS & VULCANOL,LARGO SAN MARCELLINO 10,I-80138 NAPLES,ITALY. NR 72 TC 171 Z9 171 U1 1 U2 11 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 FEB PY 1997 VL 75 IS 3-4 BP 183 EP 219 DI 10.1016/S0377-0273(96)00027-3 PG 37 WC Geosciences, Multidisciplinary SC Geology GA WK942 UT WOS:A1997WK94200001 ER PT J AU Wunderlich, B AF Wunderlich, B TI Metastable mesophases SO MACROMOLECULAR SYMPOSIA LA English DT Article; Proceedings Paper CT 2nd International Symposium on Molecular Order and Mobility in Polymer Systems CY MAY 21-24, 1996 CL ST PETERSBURG, RUSSIA SP Int Union Pure & Appl Chem, Macromolecular Div (IUPAC), Russian Acad Sci, Inst Macromolecular Compounds DE mesophase; microphase; nanophase; macromolecule; liquid crystal; plastic crystal; condis crystal; conformational disorder; phase diagram ID HEAT-CAPACITY; THERMODYNAMIC PROPERTIES; LINEAR MACROMOLECULES; PHASE-TRANSITIONS; POLYMERS; POLYETHYLENE; CRYSTALS; GROWTH; SIZE AB Mesophases are briefly summarized and defined on a uniform basis, making use of order and mobility parameters. A schematic one-component phase diagram is then reviewed that includes equilibrium as well as nonequilibrium phases. Assuming only five condensed phases (crystal, melt, glass, mesophase, and mesophase glass), fifteen different phase areas exist with simultaneous presence of up to three phases. Examples of all phase areas are documented with results from our laboratory. This scheme can be extended to more components and more than these five phases and produces then many more possible phase areas than can be handled experimentally at the present. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Wunderlich, B (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 47 TC 12 Z9 12 U1 1 U2 6 PU HUTHIG & WEPF VERLAG PI BASEL PA AUF DEM WOLF 4, CH-4052 BASEL, SWITZERLAND SN 1022-1360 J9 MACROMOL SYMP JI Macromol. Symp. PD FEB PY 1997 VL 113 BP 51 EP 65 DI 10.1002/masy.19971130108 PG 15 WC Polymer Science SC Polymer Science GA WQ303 UT WOS:A1997WQ30300007 ER PT J AU Deng, XN Moran, J Copeland, NG Gilbert, DJ Jenkins, NA Primakoff, P MartinDeLeon, PA AF Deng, XN Moran, J Copeland, NG Gilbert, DJ Jenkins, NA Primakoff, P MartinDeLeon, PA TI The mouse Spam1 maps to proximal chromosome 6 and is a candidate for the sperm dysfunction in Rb(6.16)24Lub and Rb(6.15)1Ald heterozygotes SO MAMMALIAN GENOME LA English DT Article ID GENE; TRANSLOCATION; PROTEIN; PH-20; HYALURONIDASE; SEGREGANTS; SEQUENCES; ADHESION; REGION; EGG AB We have determined the chromosomal localization of the murine gene encoding the 68-kDa sperm adhesion molecule 1, Spam1 or Ph-20. Using two independent approaches, fluorescence in situ hybridization (FISH) and interspecific backcross analysis, we show that Spam1 maps to proximal mouse Chromosome (Chr) 6. This map position is within the conserved linkage group corresponding to human Chr 7q, where the human homolog, SPAM1, has been shown to map previously. Genetic mapping shows the gene to be very closely linked to Met, one of the most proximal loci on MMU 6. It thus places the gene near the centromere and the junction of the Rb(6.16)24Lub and Rb(6.15)1Ald translocations. The essential role of the Spam1 sperm antigen in mouse sperm-egg interactions and its gene location provide strong support for its candidacy as the gene involved in the dysfunction of mouse sperm bearing the Rb(6.16)24Lub or Rb(6.15)1Ald translocation. C1 UNIV DELAWARE,DEPT BIOL,NEWARK,DE 19716. PRINCETON UNIV,DEPT MOL BIOL,PRINCETON,NJ 08544. FREDERICK CANC RES CTR,MAMMALIAN GENET LAB,ABL BASIC RES PROGRAM,FREDERICK,MD. LAWRENCE LIVERMORE NATL LAB,SECT MOL & CELL BIOL,DAVIS,CA 95616. NR 26 TC 21 Z9 21 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD FEB PY 1997 VL 8 IS 2 BP 94 EP 97 DI 10.1007/s003359900365 PG 4 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA WJ659 UT WOS:A1997WJ65900004 PM 9060406 ER PT J AU Doyle, J Ren, XJ Lennon, G Stubbs, L AF Doyle, J Ren, XJ Lennon, G Stubbs, L TI Mutations in the Cacnl1a4 calcium channel gene are associated with seizures, cerebellar degeneration, and ataxia in tottering and leaner mutant mice SO MAMMALIAN GENOME LA English DT Article ID FUNCTIONAL EXPRESSION; CHROMOSOME 19P; BRAIN; MAPS AB Tottering and leaner, two mutations of the mouse tottering locus, have been studied extensively as models for human epilepsy, Here we describe the isolation, mapping, and expression analysis of Cacnl1a4, a gene encoding the alpha subunit of a proposed P-type calcium channel, and also report the physical mapping and expression patterns of the orthologous human gene. DNA sequencing and gene expression data demonstrate that Cacnl1a4 mutations are the primary cause of seizures and ataxia in tottering and leaner mutant mice, and suggest that tottering locus mutations and human diseases, episodic ataxia 2 and familial hemiplegic migraine, represent mutations in mouse and human versions of the same channel-encoding gene. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,OAK RIDGE SCH BIOMED SCI,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94551. OI Stubbs, Lisa/0000-0002-9556-1972 NR 41 TC 99 Z9 103 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD FEB PY 1997 VL 8 IS 2 BP 113 EP 120 PG 8 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA WJ659 UT WOS:A1997WJ65900008 PM 9060410 ER PT J AU Dhar, MS Johnson, DK AF Dhar, MS Johnson, DK TI A microsatellite map of the pink-eyed dilution (p) deletion complex in mouse Chromosome 7 SO MAMMALIAN GENOME LA English DT Article ID AMINOBUTYRIC-ACID RECEPTOR; II OCULOCUTANEOUS ALBINISM; HIGH-RESOLUTION MAP; CLEFT-PALATE; PRADER-WILLI; GENETIC-MAP; MUTATIONS; LOCUS; MICE; REGIONS C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,GRAD SCH BIOMED SCI,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. FU NCI NIH HHS [5-T32-CA-09936] NR 28 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-8990 J9 MAMM GENOME JI Mamm. Genome PD FEB PY 1997 VL 8 IS 2 BP 143 EP 145 DI 10.1007/s003359900375 PG 3 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA WJ659 UT WOS:A1997WJ65900014 PM 9060416 ER PT J AU Robinson, DH Kolber, Z Sullivan, CW AF Robinson, DH Kolber, Z Sullivan, CW TI Photophysiology and photoacclimation in surface sea ice algae from McMurdo Sound, Antarctica SO MARINE ECOLOGY PROGRESS SERIES LA English DT Article DE Antarctic; sea ice algae; photoacclimation; photoinhibition; pump and probe fluorometry ID PHOTOSYNTHETIC ENERGY-CONVERSION; PHOTOSYSTEM-II; CHLOROPHYLL FLUORESCENCE; MICROBIAL COMMUNITIES; HIGH-RESOLUTION; HIGH IRRADIANCE; TEMPERATURE; PHYTOPLANKTON; LIGHT; GROWTH AB Microalgal absorption, pigment concentrations, photophysiology and the efficiency for energy conversion at photosystem II (Fv/Fm) were measured for surface ice algal communities freshly collected from saline ponds overlying fast ice in McMurdo Sound, Antarctica, during austral spring and summer 1989-90. These parameters also were measured for surface ice algae exposed in the laboratory to irradiances from 4 to 600 mu mol photons m(-2) s(-1). Freshly collected algae exhibited a pigment composition consistent with acclimation to high irradiance, which included low intracellular chlorophyll (chl) a concentrations (0.19 to 0.50 kg m(-3)), low accessory photosynthetic pigments relative to chl a (chl c: chl a = 0.16 to 0.25 mol mol(-1); fucoxanthin: chl a = 0.53 to 0.77 mol mol(-1)), and high photoprotective pigments relative to chl a (diatoxanthin + diadinoxanthin: chl a = 0.19 to 0.50 mol mol(-1)). In contrast, the photoadaptive index for freshly collected algae (E(k) = 37 to 45 mu mol photons m(-2) s(-1)) was less than the daily average photosynthetically active radiation reaching the algal communities during the study (110 to 720 mu mol photons m(-2) s(-1)), indicating that the algae were not acclimated to their high irradiance environment. No depression of photosynthesis was observed in the photosynthesis-irradiance curve at irradiances less than or equal to 250 mu mol photons m(-2) s(-1) (4- to 8-fold greater than E(k)) However, Fv/Fm (0.24 to 0.43) and the quantum yield of photosynthesis (phi(C), 0.018 to 0.037 mol C mol(-1) absorbed photons) were low in freshly collected algae, which suggests that the algae were photoinhibited under natural illumination conditions. Within 32 h after shifting algae to low irradiance, a relaxation from high-light stress was observed. Photosynthetic efficiency (alpha(b)), phi(C) and Fv/Fm increased by 165, 170 and 67%, respectively, and E(k) decreased by 60%. In addition, whereas total cellular concentrations of photosynthetic pigments were unchanged, diatoxanthin:chl a decreased by >75% due to the conversion of diatoxanthin to diadinoxanthin. The presence of xanthophyll cycling and an observed depression of relative maximum and minimum quantum yields of fluorescence in response to high irradiance indicate that algae employed the dissipation of absorbed energy from the pigment bed of photosystem II as a protection mechanism from high irradiance. Indications of additional photoprotection mechanisms and photoinhibitory damage were also observed. These results indicate that surface ice algae successfully inhabit the surface ice habitat by employing a strategy of low-light harvesting, absorbed energy dissipation, and tolerance to photoinhibitory damage. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. UNIV SO CALIF, DEPT BIOL SCI, LOS ANGELES, CA 90089 USA. RP Robinson, DH (reprint author), NASA, GODDARD SPACE FLIGHT CTR, UNIV SPACE RES ASSOC, CODE 971, GREENBELT, MD 20771 USA. NR 59 TC 28 Z9 30 U1 1 U2 13 PU INTER-RESEARCH PI OLDENDORF LUHE PA NORDBUNTE 23, D-21385 OLDENDORF LUHE, GERMANY SN 0171-8630 J9 MAR ECOL PROG SER JI Mar. Ecol.-Prog. Ser. PD FEB PY 1997 VL 147 IS 1-3 BP 243 EP 256 DI 10.3354/meps147243 PG 14 WC Ecology; Marine & Freshwater Biology; Oceanography SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Oceanography GA WP969 UT WOS:A1997WP96900022 ER PT J AU Holcomb, GR Cramer, SD AF Holcomb, GR Cramer, SD TI Nickel sulfide hollow whisker formation SO MATERIALS CHARACTERIZATION LA English DT Article ID TEMPERATURE AB Hollow, high-aspect-ratio nickel sulfide whiskers were formed during aqueous corrosion experiments at 250 degrees C by the U. S. Department of Energy. The whiskers grew radially from Teflon thread at the waterline in acidic sodium sulfate solutions containing chloride additions. The hollow morphology is consistent with that reported for the mineral millerite found in nature in hematite cavities. The data suggest that iron and chloride impurities are necessary for the observed whisker structure. (C) Elsevier Science Inc., 1997. RP Holcomb, GR (reprint author), US DOE,ALBANY RES CTR,ALBANY,OR 97321, USA. RI Holcomb, Gordon/G-9070-2013 OI Holcomb, Gordon/0000-0003-3542-5319 NR 13 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-5803 J9 MATER CHARACT JI Mater. Charact. PD FEB PY 1997 VL 38 IS 2 BP 67 EP 73 DI 10.1016/S1044-5803(97)80025-3 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Characterization & Testing SC Materials Science; Metallurgy & Metallurgical Engineering GA XG797 UT WOS:A1997XG79700002 ER PT J AU Paranthaman, M David, KA Lindemer, TB AF Paranthaman, M David, KA Lindemer, TB TI Phase equilibria of the MgO-Cu2O-CuO system SO MATERIALS RESEARCH BULLETIN LA English DT Article DE oxides; chemical synthesis; thermogravimetric analysis; X-ray diffraction; phase equilibria ID SUBSTITUTION AB Phase equilibria of the MgO-Cu2O-CuO system have been determined in air at temperatures ranging from 850 to 1100 degrees C. The starting compositions ranged from 0 to 100% Mg in (Mg1-xCux)O. CuO was quite soluble in MgO. The solubility of CuO in MgO at 850 degrees C was about 9% and at 1050 degrees C was about 20%. The only known ternary Guggenite phase had a composition of Cu2MgO3. The Guggenite phase exists in three forms, namely, Guggenite A (G(A), orthorhombic, space group Pmmn(59)), Guggenite B (G(B), orthorhombic, space group I(0)), and Guggenite X (G(X), monoclinic). Guggenite A was obtained as a single phase in air at x(CuO) = 67% (i.e., 67% CuO and 33% MgO) and 1000 degrees C. It undergoes a phase transition to the Guggenite X phase when it is heated above 1050 degrees C. The Guggenite B phase was obtained in a mixture at x(CuO) = 75% and at temperatures above 1050 degrees C. MgO was not found to be soluble in CuO. For samples with x(CuO) greater than or equal to 67%, the Guggenite A phase coexisted with tenorite (CuO, monoclinic) at temperatures less than or equal to 1000 degrees C and above 1021 degrees C, it was in equilibrium with cuprite (Cu2O, cubic). For CuO compositions between 20% and 67%, a mixture of Guggenite A phase and the periclase phase (MgO, cubic) was obtained at temperatures less than or equal to 1000 degrees C. The decomposition of Cu2MgO3 (Guggenite A) phase was determined at several oxygen partial pressures and the Gibbs free energy of formation of this phase was also calculated. Copyright (C) 1997 Elsevier Science Ltd. C1 OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Paranthaman, M (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI Paranthaman, Mariappan/N-3866-2015 OI Paranthaman, Mariappan/0000-0003-3009-8531 NR 12 TC 14 Z9 14 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0025-5408 J9 MATER RES BULL JI Mater. Res. Bull. PD FEB PY 1997 VL 32 IS 2 BP 165 EP 173 DI 10.1016/S0025-5408(96)00184-5 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA WG368 UT WOS:A1997WG36800004 ER PT J AU Suryanarayana, C Korth, GE Froes, FH AF Suryanarayana, C Korth, GE Froes, FH TI Compaction and characterization of mechanically: Alloyed nanocrystalline titanium aluminides SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID POWDERS; EVOLUTION AB Blended elemental (BE) Ti-24 at; pet Al-ii at. pet Nb (Ti-24-11) and Ti-55 at. pet-Al (Ti-55) powders and prealloyed (PA) Ti-24-11 powders were mechanically alloyed in a SPEX mill or an attritor. After SPEX milling for 10 hours, the BE Ti-24-11 powder contained the B2/bcc phase, while the BE Ti-55 powder showed the presence of an amorphous phase. The PA Ti-24-11 powder containing the B2 phase showed a decrease of crystal size on milling. These powders were consolidated by hot isostatic pressing (''hipping''), Ceracon process, and dynamic methods. On compaction,,the B2/bcc phase in the Ti-24-11 sample transformed to a mixture of the B2 and orthorhombic (''O''), phases, while the amorphous phase in the Ti-55 powder crystallized to a mixture of the gamma-TiAl and alpha(2)-Ti3Al phases. The finest grain size in compacted material was obtained in the dynamically consolidated powder, and the grain size in the-hot isostatic pressed (''hipped'') powder became larger with the increasing hipping temperature. C1 UNIV IDAHO,INST MAT & ADV PROC,MOSCOW,ID 83844. UNIV IDAHO,DEPT MET ENGN,MOSCOW,ID 83844. LOCKHEED MARTIN IDAHO TECHNOL CO,DIV MET & CERAM,IDAHO FALLS,ID 83415. RI Suryanarayana, C/B-9314-2008 NR 27 TC 38 Z9 39 U1 0 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD FEB PY 1997 VL 28 IS 2 BP 293 EP 302 DI 10.1007/s11661-997-0132-4 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WL436 UT WOS:A1997WL43600005 ER PT J AU Klueh, RL Alexander, DJ Maziasz, PJ AF Klueh, RL Alexander, DJ Maziasz, PJ TI Bainitic chromium-tungsten steels with 3 pct chromium SO METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE LA English DT Article ID CR-W STEELS; MICROSTRUCTURE; BEHAVIOR AB Previous work on 3Cr-1.5MoV (nominally Fe-3Cr-2.5Mo-0.25V-0.1C), 2.25Cr-2W (Fe-2.25Cr-2W-0.1C), and 2.25Cr-2WV (Fe-2.25Cr-2W-0.25V-0.1C) steels indicated that the impact toughness of these steels depended on the microstructure of the bainite formed during continuous cooling from the austenitization temperature. Microstructures formed during continuous cooling can differ from classical upper and lower bainite formed during isothermal transformation. Two types of nonclassical microstructures were observed depending on the cooling rate: carbide-free acicular bainite at rapid cooling rates and granular bainite at slower cooling rates. The Charpy impact toughness of the acicular ferrite was considerably better than;for the granular bainite. It was postulated that alloying to improve the hardenability of the steel would promote the formation of acicular bainite, just as increasing the cooling rate does. To test this, chromium and tungsten were added to the 2.25Cr-2W and 2.25Cr-2WV steel compositions to increase their hardenability. Charpy testing indicated that the new 3Cr-W and 3Cr-WV steels had improved impact toughness, as demonstrated by lower ductile-brittle transition temperatures and higher upper-shelf energies. This improvement occurred with less. tempering than was necessary to achieve similar toughness fdr the 2.25Cr steels and for high-chromium (9 to 12 pet Cr) Cr-W and Cr-Mo steels. RP Klueh, RL (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. OI Maziasz, Philip/0000-0001-8207-334X NR 28 TC 17 Z9 17 U1 2 U2 4 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1073-5623 J9 METALL MATER TRANS A JI Metall. Mater. Trans. A-Phys. Metall. Mater. Sci. PD FEB PY 1997 VL 28 IS 2 BP 335 EP 345 DI 10.1007/s11661-997-0136-0 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WL436 UT WOS:A1997WL43600009 ER PT J AU Lubkowitz, MA Hauser, L Breslav, M Naider, F Becker, JM AF Lubkowitz, MA Hauser, L Breslav, M Naider, F Becker, JM TI An oligopeptide transport gene from Candida albicans SO MICROBIOLOGY-UK LA English DT Article DE Candida albicans; peptide transport; Saccharomyces cerevisiae ID PEPTIDE-TRANSPORT; SACCHAROMYCES-CEREVISIAE; SEQUENCE-ANALYSIS; SHUTTLE VECTORS; PERMEASES; ALIGNMENT; DIPEPTIDE; PROTEINS; YEAST AB A Candida albicans oligopeptide transport gene, OPT1. was cloned from a C. albicans genomic library through heterologous expression in the Saccharomyces cerevisiae di-/tripeptide transport mutant PB1X-9B. When transformed with a plasmid harbouring OPT1, S. cerevisiae PB1X-9B, which did not express tetra-/pentapeptide transport activity under the conditions used, was conferred with an oligopeptide transport phenotype, as indicated by growth on the tetrapeptide Lys-Leu-Leu-Gly, sensitivity to toxic tetra- and pentapeptides, and an increase in the initial uptake rate of the radiolabelled tetrapeptide Lys-Leu-Gly-[H-3]Leu. The level of oligopeptide transport was found to be influenced in the heterologous host by the source of nitrogen used for growth. The entire 3.8 kb fragment containing the oligopeptide transport activity was sequenced and an ORF of 2349 nucleotides containing a 58 nucleotide intron was identified. The deduced protein product of 783 amino acid residues contained 12 hydrophobic regions suggestive of a membrane transport protein. Sequence comparisons revealed that similar proteins are encoded by genes from S. cerevisiae and Schisosaccharomyces pombe and that OPT1 is not a member of the ABC or PTR membrane transport families. C1 UNIV TENNESSEE,DEPT MICROBIOL,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT BIOCHEM CELLULAR & MOL BIOL,KNOXVILLE,TN 37996. UNIV TENNESSEE,GRAD SCH BIOMED SCI,DIV BIOL,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. CUNY COLL STATEN ISL,DEPT CHEM,STATEN ISL,NY 10314. RI Hauser, Loren/H-3881-2012 NR 35 TC 71 Z9 76 U1 0 U2 0 PU SOC GENERAL MICROBIOLOGY PI READING PA MARLBOROUGH HOUSE, BASINGSTOKE RD, SPENCERS WOODS, READING, BERKS, ENGLAND RG7 1AE SN 1350-0872 J9 MICROBIOL-UK JI Microbiology-(UK) PD FEB PY 1997 VL 143 BP 387 EP 396 PN 2 PG 10 WC Microbiology SC Microbiology GA WH225 UT WOS:A1997WH22500014 PM 9043116 ER PT J AU Wall, MA Barbee, TW Weihs, TP AF Wall, MA Barbee, TW Weihs, TP TI Preparation of multilayered materials in cross-section for in situ TEM tensile deformation studies SO MICROSCOPY RESEARCH AND TECHNIQUE LA English DT Article DE thick films; cross-section; precision ion milling ID SPECIMEN PREPARATION; ELECTRON-MICROSCOPY; DEFECTS; METAL AB The success of in Situ transmission electron microscopy experimentation is often dictated by proper specimen preparation and sample design procedures. We have developed a novel technique permitting the production of tensile specimens of multilayered films in cross-section for in situ deformation studies. Of primary importance in the development of this technique is the production of an electron transparent micro-gauge section. This micro-gauge section predetermines the position at which plastic deformation, crack nucleation and growth, and failure are observed. In short, we report in detail, a unique combination of specimen preparation procedural steps and the design of a multilayer foil sample. The ability of these procedures to facilitate the success of in situ TEM: tensile studies of layered materials in cross-section is demonstrated using a Cu-Zr multilayer foil. (C) 1997 Wiley-Liss, Inc. RP Wall, MA (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,7000 EAST AVE,LIVERMORE,CA 94550, USA. RI Weihs, Timothy/A-3313-2010 NR 16 TC 1 Z9 1 U1 1 U2 7 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 1059-910X J9 MICROSC RES TECHNIQ JI Microsc. Res. Tech. PD FEB 1 PY 1997 VL 36 IS 3 BP 143 EP 150 DI 10.1002/(SICI)1097-0029(19970201)36:3<143::AID-JEMT1>3.0.CO;2-Q PG 8 WC Anatomy & Morphology; Biology; Microscopy SC Anatomy & Morphology; Life Sciences & Biomedicine - Other Topics; Microscopy GA WL995 UT WOS:A1997WL99500001 PM 9080403 ER PT J AU Norton, GA McClelland, JF AF Norton, GA McClelland, JF TI Rapid determination of limestone using photoacoustic spectroscopy SO MINERALS ENGINEERING LA English DT Article DE process instrumentation; industrial minerals AB Rapid and accurate determinations of limestone in lime products would be useful for process control applications in the lime industry. The loss-on-ignition method commonly used for determining residual limestone is very time consuming and prone to error. In this study, the feasibility of using photoacoustic spectroscopy (PAS) as a process control tool in the lime industry was investigated. Results from preliminary PAS measurements on samples prepared in the laboratory indicated that a low-cost dedicated analyzer employing PAS has excellent potential. (C) 1997 Elsevier Science Ltd. RP Norton, GA (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0892-6875 J9 MINER ENG JI Miner. Eng. PD FEB PY 1997 VL 10 IS 2 BP 237 EP 240 DI 10.1016/S0892-6875(96)00149-5 PG 4 WC Engineering, Chemical; Mineralogy; Mining & Mineral Processing SC Engineering; Mineralogy; Mining & Mineral Processing GA WK621 UT WOS:A1997WK62100010 ER PT J AU Berguer, R Remler, M Beckley, D AF Berguer, R Remler, M Beckley, D TI Laparoscopic instruments cause increased forearm fatigue: A subjective and objective comparison of open and laparoscopic techniques SO MINIMALLY INVASIVE THERAPY & ALLIED TECHNOLOGIES LA English DT Article DE laparoscopy; ergonomics; surgical instruments; electromyography; fatigue ID ELECTROMYOGRAPHIC ACTIVITY; WORK; THUMB AB Background: Endoscopic surgery presents new ergonomic conditions for surgeons that may cause fatigue and decreased performance during prolonged laparoscopic procedures, This study uses a post-operative questionnaire and surface electromyography (EMG) to compare upper extremity discomfort and muscle contraction during real and simulated laparoscopic and open surgical tasks. Methods: We asked surgeons to rank upper extremity discomfort immediately following laparoscopic or open operations on a scale of 0-3. We also measured the surface EMG activity of the right upper forearm flexor and extensor compartment, Deltoid and Trapezius muscles in three surgeons during simulated surgical tasks, The maximum voluntary contraction (MVC) for each muscle was used to normalize the data between subjects. Statistical comparisons were carried out using paired t-tests and P < 0.05. Results: Surgeons reported a significant increase in moderate/severe discomfort of the dominant foream following laparascopic operations. We found a significant increase in forearm flexor muscle contraction during tasks performed with the laparoscopic instrument compared to the haemostat (P = 0.01), Task repetition resulted in significant increases in the Deltoid (P = 0.02) and EDC (P = 0.05) muscle contractions with the laparoscopic instrument only. Conclusion: Use of laparoscopic instruments results in greater forearm discomfort, possibly due to the need for increased forearm flexor muscle contractions compared to conventional surgical instruments. Further studies and design changes are needed to optimize laparoscopic Instrument design. RP Berguer, R (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT SURG, 150 MUIR RD 112, MARTINEZ, CA 94553 USA. NR 21 TC 22 Z9 22 U1 3 U2 5 PU INFORMA HEALTHCARE PI LONDON PA TELEPHONE HOUSE, 69-77 PAUL STREET, LONDON EC2A 4LQ, ENGLAND SN 1364-5706 J9 MINIM INVASIV THER JI Minim. Invasive Ther. Allied Technol. PD FEB PY 1997 VL 6 IS 1 BP 36 EP 40 DI 10.3109/13645709709152824 PG 5 WC Surgery SC Surgery GA WN008 UT WOS:A1997WN00800009 ER PT J AU Dees, C Askari, M Foster, JS Ahamed, S Wimalasena, J AF Dees, C Askari, M Foster, JS Ahamed, S Wimalasena, J TI DDT mimicks estradiol stimulation of breast cancer cells to enter the cell cycle SO MOLECULAR CARCINOGENESIS LA English DT Article DE cyclin-dependent kinase; xenoestrogen; promotion; kinase; DDT; retinoblastoma gene product ID ESTROGEN-RECEPTOR; PROTEIN-KINASE; D1 AB Estrogens play a critical role in the etiology of found breast cancer. Estradiol promotes the growth of breast cancer cells in vivo and in vitro. Exogenous estrogens in both the environment and in the human diet increase the growth of breast cancer cells in vitro. A role for xenoestrogens in breast cancer etiology has been proposed but remains controversial. We examined the effects of the xenoestrogenic pesticide 1,1,1 -trichloro-2,2-bis(chlorophenyl)ethane (DDT) on estrogen-receptor (ER)-positive MCF-7 and T-47D human breast cancer cells as well as on ER-negative HS 578Bst breast cancer cells and rat liver cells. Estradiol and DDT were found to increase the growth of MCF-7 cells in the presence of insulin. The activity of cyclin-dependent kinase (Cdk)2 increased in growth-arrested T-47D and MCF-7 cells treated with beta-estradiol or DDT. The steroidal antiestrogen ICI 182,780 prevented both growth and Cdk2 activation induced by estradiol or DDT. Increased phosphorylation of Cdk2 and the retinoblastoma protein (pRb105) was observed in ER-positive cells treated with DDT or estradiol. Cdk2 activity was not affected by DDT or estradiol in ER-negative HS 578Bst breast cancer cells or in rat liver epithelial cells. Cyclin D1 protein synthesis was increased by DDT and estradiol in MCF-7 cells. DDT and estradiol-induced ER-dependent transcriptional activation of estrogen response elements (EREs) in stably transfected MVLN cells, and ERE activation by low doses of DDT was increased by insulin. These findings suggest that DDT can stimulate breast cancer cells to enter into the cell cycle by directly affecting key regulatory elements. The relative potency of DDT in inducing cell-cycle progression appears to be only 100-300 times less than that of estradiol when measured in the presence of insulin. Therefore, the cancer risks associated with DDT exposure may be greater than first thought, especially when additional mitogenic stimuli are present. (C) 1997 Wiley-Liss, Inc.double dagger C1 OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. UNIV TENNESSEE,KNOXVILLE,TN. UNIV TENNESSEE HOSP,DEPT OBSTET & GYNECOL,KNOXVILLE,TN. NR 32 TC 50 Z9 51 U1 1 U2 5 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0899-1987 J9 MOL CARCINOGEN JI Mol. Carcinog. PD FEB PY 1997 VL 18 IS 2 BP 107 EP 114 DI 10.1002/(SICI)1098-2744(199702)18:2<107::AID-MC6>3.0.CO;2-D PG 8 WC Biochemistry & Molecular Biology; Oncology SC Biochemistry & Molecular Biology; Oncology GA WL325 UT WOS:A1997WL32500006 PM 9049186 ER PT J AU Phillips, JM AF Phillips, JM TI EC-NSF workshop on materials recommends pilot areas for international cooperation SO MRS BULLETIN LA English DT Editorial Material RP Phillips, JM (reprint author), SANDIA NATL LABS,SURFACE & SENSOR CONTROLLED PROC DEPT,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0883-7694 J9 MRS BULL JI MRS Bull. PD FEB PY 1997 VL 22 IS 2 BP 13 EP 13 PG 1 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WH736 UT WOS:A1997WH73600011 ER PT J AU Eisenberg, D AF Eisenberg, D TI Into the black of night SO NATURE STRUCTURAL BIOLOGY LA English DT Editorial Material AB Protein structure of prediction methods, critically assessed at Asilomar. California, are starting to work, combining ideas descended from two lines of thought: from Darwin and from Boltzmann and Schrodinger. RP Eisenberg, D (reprint author), UNIV CALIF LOS ANGELES,US DOE,LAB STRUCT BIOL & MOL MED,BOX 95157,LOS ANGELES,CA 90025, USA. NR 0 TC 20 Z9 21 U1 0 U2 1 PU NATURE PUBLISHING CO PI NEW YORK PA 345 PARK AVE SOUTH, NEW YORK, NY 10010-1707 SN 1072-8368 J9 NAT STRUCT BIOL JI Nat. Struct. Biol. PD FEB PY 1997 VL 4 IS 2 BP 95 EP 97 DI 10.1038/nsb0297-95 PG 3 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA WF961 UT WOS:A1997WF96100005 PM 9033584 ER PT J AU Mitchison, HM Taschner, PEM Kremmidiotis, G Callen, DF Doggett, NA Lerner, TJ Janes, RB Wallace, BA Munroe, PB ORawe, AM Gardiner, RM Mole, SE AF Mitchison, HM Taschner, PEM Kremmidiotis, G Callen, DF Doggett, NA Lerner, TJ Janes, RB Wallace, BA Munroe, PB ORawe, AM Gardiner, RM Mole, SE TI Structure of the CLN3 gene and predicted structure, location and function of CLN3 protein SO NEUROPEDIATRICS LA English DT Article; Proceedings Paper CT 6th International Congress on Neuronal Ceroid Lipofuscinoses (NCL-96) CY JUN 08-11, 1996 CL GUSTAVEHUND, FINLAND DE CLN3 gene; protein; juvenile NCL AB The genomic sequence of the human CLN3 gene, which is defective in juvenile onset neuronal ceroid lipofuscinosis (Batten disease) is being delineated using a variety of methods, A Sacchoromyces cerevisiae gene, YHC3 (for Yeast Homologue to human CLN3), which is highly similar to the human disease gene, has been identified by computer-aided homology searching, Topology predictions indicate the CLN3 protein contains six transmembrane segments, Most similarity between the human and yeast proteins lies either in the transmembrane segments or along one face of the predicted protein structure. C1 LEIDEN UNIV, DEPT HUMAN GENET, SYLVIUS LAB, NL-2333 AL LEIDEN, NETHERLANDS. WOMENS & CHILDRENS HOSP, DEPT CYTOGENET & MOL GENET, ADELAIDE, SA, AUSTRALIA. LOS ALAMOS NATL LAB, DIV LIFE SCI, LOS ALAMOS, NM USA. LOS ALAMOS NATL LAB, CTR HUMAN GENOME STUDIES, LOS ALAMOS, NM USA. MASSACHUSETTS GEN HOSP, MOL NEUROGENET UNIT, CHARLESTOWN, MA USA. UNIV LONDON, BIRKBECK COLL, DEPT CRYSTALLOG, LONDON WC1E 7HX, ENGLAND. RP Mitchison, HM (reprint author), UCL, SCH MED, RAYNE INST, DEPT PAEDIAT, 5 UNIV ST, LONDON WC1E 6JJ, ENGLAND. RI Mole, Sara/C-2024-2008; Janes, Robert/A-6164-2011; Callen, David/G-1975-2012; Taschner, Peter/J-8853-2014; Wallace, B. A./C-3753-2008; OI Taschner, Peter/0000-0001-9621-465X; Wallace, B. A./0000-0001-9649-5092; Callen, David/0000-0002-6189-9991; Mole, Sara/0000-0003-4385-4957 FU NINDS NIH HHS [NS30152, NS28722, NS32009]; Wellcome Trust NR 5 TC 16 Z9 16 U1 0 U2 0 PU GEORG THIEME VERLAG KG PI STUTTGART PA RUDIGERSTR 14, D-70469 STUTTGART, GERMANY SN 0174-304X J9 NEUROPEDIATRICS JI Neuropediatrics PD FEB PY 1997 VL 28 IS 1 BP 12 EP 14 DI 10.1055/s-2007-973656 PG 3 WC Clinical Neurology; Pediatrics SC Neurosciences & Neurology; Pediatrics GA XA124 UT WOS:A1997XA12400005 PM 9151311 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Logan, J Abumrad, NN Hitzemann, RJ Pappas, NS Pascani, K AF Wang, GJ Volkow, ND Fowler, JS Logan, J Abumrad, NN Hitzemann, RJ Pappas, NS Pascani, K TI Dopamine D-2 receptor availability in opiate-dependent subjects before and after naloxone-precipitated withdrawal SO NEUROPSYCHOPHARMACOLOGY LA English DT Article DE naloxone; opiate abuse; PET, withdrawal ID POSITRON EMISSION TOMOGRAPHY; HUMAN-BRAIN; MORPHINE-WITHDRAWAL; NUCLEUS-ACCUMBENS; C-11 RACLOPRIDE; COCAINE; BINDING; RELEASE; RATS; MICRODIALYSIS AB Dopamine may play a role in opiate withdrawal and dependence. We measured dopamine D-2 receptor availability in 11 opiate-dependent subjects using PET and [C-11]raclopride at baseline and during naloxone precipitated withdrawal. Because [C-11]raclopride is sensitive to endogenous dopamine, this strategy enabled us to test whether we could document in humans the DA reductions reported in animal models of opiate withdrawal. Results were compared with values from 11 controls, two of which also received naloxone. The ratio of the distribution volume in striatum to that in cerebellum (B-max/K-d+1) was used as model parameter for D-2 receptor availability. Baseline measures for B-max/K-d were lower in opiatedependent subjects (2.44 +/- 0.4) than in controls (2.97 +/- 0.45, p less than or equal to .009). Naloxone precipitated an intense withdrawal in the abusers but did not change the B-max/K-d ratio. This study documents decreases in D-2 receptors in opiate-dependent subjects but does not document significant changes in striatal DA concentration during acute withdrawal. (C) 1997 American College of Neuropsychopharmacology [Neuropsychopharmacology 16:174-182, 1997] C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. SUNY STONY BROOK,DEPT RADIOL,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. VET AFFAIRS MED CTR,PSYCHIAT SERV,NORTHPORT,NY. N SHORE UNIV HOSP,DEPT SURG,MANHASSET,NY. 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-DA06891] NR 32 TC 140 Z9 142 U1 1 U2 4 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0893-133X J9 NEUROPSYCHOPHARMACOL JI Neuropsychopharmacology PD FEB PY 1997 VL 16 IS 2 BP 174 EP 182 DI 10.1016/S0893-133X(96)00184-4 PG 9 WC Neurosciences; Pharmacology & Pharmacy; Psychiatry SC Neurosciences & Neurology; Pharmacology & Pharmacy; Psychiatry GA WD962 UT WOS:A1997WD96200011 PM 9015800 ER PT J AU Hawkes, GL AF Hawkes, GL TI Simulating soil melting with CFD SO NUCLEAR ENGINEERING INTERNATIONAL LA English DT Article RP Hawkes, GL (reprint author), LOCKHEED MARTIN IDAHO TECHNOL,IDAHO FALLS,ID, USA. OI Hawkes, Grant/0000-0003-3496-8100 NR 0 TC 2 Z9 2 U1 0 U2 0 PU REED BUSINESS PUBLISHING LTD PI SUTTON PA QUADRANT HOUSE THE QUADRANT, SUTTON, SURREY, ENGLAND SM2 5AS SN 0029-5507 J9 NUCL ENG INT JI Nucl. Eng. Int. PD FEB PY 1997 VL 42 IS 511 BP 28 EP 29 PG 2 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WL928 UT WOS:A1997WL92800008 ER PT J AU Levedahl, WK Lindl, JD AF Levedahl, WK Lindl, JD TI Energy scaling of inertial confinement fusion targets for ignition and high gain SO NUCLEAR FUSION LA English DT Article AB The dependence of the ignition threshold on the velocity nu(imp) and compressibility of an imploding fuel mass is central to establishing the driver requirements and implosion strategy for inertial confinement fusion (ICF). Using a series of LASNEX calculations, it is found that ke(imp) proportional to nu(imp)(-alpha)beta(a), where ke(imp) is the kinetic energy in the imploding fuel at the ignition threshold, alpha = 5.5+/-0.5, a = 1.7+/-0.2 and nu(imp) is the implosion velocity. Here, the compressibility parameter beta is related to the pressure P and density rho of the DT fuel by the relation P = beta rho(5/3). These results are obtained by starting at the peak implosion velocity for a fuel shell of a high gain ICF capsule and scaling the isentrope, mass and velocity of the fuel shell. In the presence of a mix of hot and cold material at the edge of the central hot spot, it is also found that the results can be fitted by assuming that the reduced clean fuel radius for a mixed capsule requires a velocity increase of the same magnitude as that which would be required if the entire capsule had been rescaled in size by the same ratio. RP Levedahl, WK (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 15 TC 37 Z9 37 U1 0 U2 5 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 FEB PY 1997 VL 37 IS 2 BP 165 EP 173 DI 10.1088/0029-5515/37/2/I01 PG 9 WC Physics, Fluids & Plasmas SC Physics GA XP370 UT WOS:A1997XP37000002 ER PT J AU Abrakov, VV Akulina, DK Andryukhina, ED Batanov, GM Berezhetskij, MS Danilkin, IS Donskaya, NP Fedyanin, OI Gladkov, GA Grebenshchikov, SE Harris, JH Kharchev, NK Kholnov, YV Kolik, LV Kovrizhnykh, LM Larionova, NF Letunov, AA Likin, KM Lyon, JF Meshcheryakov, AI Nechaev, YI Petrov, AE Sarksyan, KA Sbitnikova, IS AF Abrakov, VV Akulina, DK Andryukhina, ED Batanov, GM Berezhetskij, MS Danilkin, IS Donskaya, NP Fedyanin, OI Gladkov, GA Grebenshchikov, SE Harris, JH Kharchev, NK Kholnov, YV Kolik, LV Kovrizhnykh, LM Larionova, NF Letunov, AA Likin, KM Lyon, JF Meshcheryakov, AI Nechaev, YI Petrov, AE Sarksyan, KA Sbitnikova, IS TI High power density electron cyclotron experiments in the L-2M stellarator SO NUCLEAR FUSION LA English DT Article ID CONFINEMENT AB The results of electron cyclotron heating (ECH) experiments in the L-2M stellarator are presented. The main goal of the experiments is to investigate the physics of ECH and of plasma confinement at high values of the volume heating power density. A current free plasma is produced and heated by extraordinary waves at the second harmonic of the electron cyclotron frequency (omega(0)=2 omega(ce)). The experimental results are compared with the empirical LHD scaling and with numerical simulations of plasma confinement and heating processes based on neoclassical theory using the full matrix of transport coefficients, including some additional anomalous corrections. C1 CTR ETUD CADARACHE,ST PAUL DURANCE,FRANCE. OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Abrakov, VV (reprint author), RUSSIAN ACAD SCI,INST GEN PHYS,38 VAVILOV ST,MOSCOW,RUSSIA. RI Batanov, German/Q-1825-2015 OI Batanov, German/0000-0001-5715-2601 NR 16 TC 25 Z9 30 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0029-5515 J9 NUCL FUSION JI Nucl. Fusion PD FEB PY 1997 VL 37 IS 2 BP 233 EP 239 DI 10.1088/0029-5515/37/2/I08 PG 7 WC Physics, Fluids & Plasmas SC Physics GA XP370 UT WOS:A1997XP37000008 ER PT J AU Alexeev, G Auffray, E Baillon, P Barney, D Bassompierre, G Bateman, E Bell, KW Benhammou, Y Bloch, P Bomestar, D Borgia, B Bourotte, J Burge, S Cameron, W Chipaux, R Cockerill, D Connolly, J Dafinei, I Denes, P Depasse, P Deiters, K Dobrzynski, L ElMamouni, H Faure, JL Felcini, M Finger, M Flugel, T Gautheron, F Givernaud, A Gninenko, S Godinovic, N Graham, DJ Guillaud, JP Guschin, E Haguenauer, M Hillemanns, H Hofer, H Ille, B Jaaskelainen, S Katchanov, V Kennedy, B Kirn, T Korzhik, M LassilaPerini, K Lebeau, M Lebrun, P Lecoq, P Lecoeur, G Lecomte, P Leonardi, E Locci, E Loos, R Ma, D Martin, F Mendiburu, JP Musienko, Y Nedelec, P NessiTedaldi, F Newbold, D Newman, H Oukhanov, M Pacciani, L Peigneux, JP Pirro, S Popov, S Puljak, I Purves, C Renker, D Rondeaux, F Rosso, E Rusack, R Rykaczewski, H Schmitz, D Schneegans, M Schwenke, J Seez, C Semeniouk, I Shagin, P Shevchenko, S Shi, X Sillou, D Simohand, D Singovsky, A Soric, I Smith, B Stephenson, R Verrecchia, P Vialle, JP Virdee, TS Zhu, RY AF Alexeev, G Auffray, E Baillon, P Barney, D Bassompierre, G Bateman, E Bell, KW Benhammou, Y Bloch, P Bomestar, D Borgia, B Bourotte, J Burge, S Cameron, W Chipaux, R Cockerill, D Connolly, J Dafinei, I Denes, P Depasse, P Deiters, K Dobrzynski, L ElMamouni, H Faure, JL Felcini, M Finger, M Flugel, T Gautheron, F Givernaud, A Gninenko, S Godinovic, N Graham, DJ Guillaud, JP Guschin, E Haguenauer, M Hillemanns, H Hofer, H Ille, B Jaaskelainen, S Katchanov, V Kennedy, B Kirn, T Korzhik, M LassilaPerini, K Lebeau, M Lebrun, P Lecoq, P Lecoeur, G Lecomte, P Leonardi, E Locci, E Loos, R Ma, D Martin, F Mendiburu, JP Musienko, Y Nedelec, P NessiTedaldi, F Newbold, D Newman, H Oukhanov, M Pacciani, L Peigneux, JP Pirro, S Popov, S Puljak, I Purves, C Renker, D Rondeaux, F Rosso, E Rusack, R Rykaczewski, H Schmitz, D Schneegans, M Schwenke, J Seez, C Semeniouk, I Shagin, P Shevchenko, S Shi, X Sillou, D Simohand, D Singovsky, A Soric, I Smith, B Stephenson, R Verrecchia, P Vialle, JP Virdee, TS Zhu, RY TI Studies of lead tungstate crystal matrices in high energy beams for the CMS electromagnetic calorimeter at the LHC SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE lead tungstate; crystal; CMS; ECAL; electromagnetic calorimeter; energy resolution; APD AB Using matrices of lead tungstate crystals, energy resolutions better than 0.6% at 100 GeV have been achieved in the test beam in 1995. It has been demonstrated that a lead tungstate electromagnetic calorimeter read out by avalanche photodiodes can consistently achieve the excellent energy resolutions necessary to justify its construction in the CMS detector. The performance achieved has been understood in terms of the properties of the crystals and photodetectors. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,LONDON,ENGLAND. RHEIN WESTFAL TH AACHEN,AACHEN,GERMANY. LAPP,ANNECY,FRANCE. UNIV BRISTOL,BRISTOL,AVON,ENGLAND. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CERN,GENEVA,SWITZERLAND. SACLAY,GIF SUR YVETTE,FRANCE. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. INST NUCL PROBLEMS,MINSK,BYELARUS. INR,MOSCOW,RUSSIA. ECOLE POLYTECH,LPNHE,PALAISEAU,FRANCE. CALTECH,PASADENA,CA 91125. CHARLES UNIV,PRAGUE,CZECH REPUBLIC. IHEP,PROTVINO,RUSSIA. PRINCETON UNIV,PRINCETON,NJ 08544. UNIV ROMA LA SAPIENZA,ROME,ITALY. TECH UNIV SPLIT,SPLIT,CROATIA. IPN LYON,IN2P3,CNRS,VILLEURBANNE,FRANCE. UNIV LYON 1,F-69622 VILLEURBANNE,FRANCE. PAUL SCHERRER INST,VILLIGEN,SWITZERLAND. ETH ZURICH,ZURICH,SWITZERLAND. RI Chipaux, Remi/G-1145-2010; gushchin, evgeny/J-3648-2014; korzhik, Mikhail/E-9505-2014; OI gushchin, evgeny/0000-0001-8857-1665; Pacciani, Luigi/0000-0001-6897-5996 NR 3 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 1 PY 1997 VL 385 IS 3 BP 425 EP 434 DI 10.1016/S0168-9002(96)01030-3 PG 10 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WJ772 UT WOS:A1997WJ77200007 ER PT J AU Hull, EL Pehl, RH Stanley, MR Foster, CC Komisarcik, K East, GW Vanderwerp, JD Friesel, DL AF Hull, EL Pehl, RH Stanley, MR Foster, CC Komisarcik, K East, GW Vanderwerp, JD Friesel, DL TI A N-16 gamma-ray facility SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE nitrogen-16; gamma ray; germanium detector AB A practical N-16 gamma-ray source is created in a medium-energy cyclotron environment. A N-16 source emits 6129 and 7115 keV gamma rays. The viability of this several mu Ci source for detector calibration and studying detector physics is established. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. CLEMSON UNIV,CLEMSON,SC 29632. RP Hull, EL (reprint author), INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47408, USA. NR 3 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 1 PY 1997 VL 385 IS 3 BP 489 EP 491 DI 10.1016/S0168-9002(96)01028-5 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WJ772 UT WOS:A1997WJ77200016 ER PT J AU Burks, M Trentalange, S Margetis, S Wieman, H AF Burks, M Trentalange, S Margetis, S Wieman, H TI Electron drift parameters in dimethyl ether SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB We have measured electron drift parameters in dimethyl ether gas over distances up to 14 cm and drift fields up to 1600 V/cm. By careful control of impurity levels, the attenuation of signals in the gas can be brought to manageable levels. Above 1000 V/cm, the attenuation of ionization signals due to attachment by electro-negative impurities is measured to be less than 0.5%/cm, making this gas an attractive candidate for use in small time projection chambers. C1 UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90095. UNIV ARKANSAS,DEPT APPL SCI,LITTLE ROCK,AR 72204. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 1 PY 1997 VL 385 IS 3 BP 519 EP 522 DI 10.1016/S0168-9002(96)00929-1 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WJ772 UT WOS:A1997WJ77200020 ER PT J AU Barrette, J Dai, Y Filimonov, K Gan, D Mark, SK Qi, YJ Rosati, M Starinski, N Wang, M Zhang, B Yu, B Libby, B AF Barrette, J Dai, Y Filimonov, K Gan, D Mark, SK Qi, YJ Rosati, M Starinski, N Wang, M Zhang, B Yu, B Libby, B TI A study of MWPC with chevron cathode pad readout SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PROPORTIONAL-COUNTERS; IMPACT RECONSTRUCTION; HIGH-RESOLUTION; WIRE CHAMBERS; POSITION; COORDINATE; DETECTOR AB An investigation of MWPCs with interpolating chevron shaped cathode pad readout has been carried out as pair of the R&D for the particle tracking system of the PHENIX detector at RHIC. Two prototype chambers were designed and constructed. Their response to minimum ionizing particles was tested with secondary beams from the AGS accelerator system at the Brookhaven National Laboratory. Results on resolution, differential non-linearity and overall performance for different chevron patterns and cell geometries are presented. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. IOWA STATE UNIV,AMES,IA 50011. RP Barrette, J (reprint author), MCGILL UNIV,FOSTER RADIAT LAB,MONTREAL,PQ,CANADA. NR 21 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 1 PY 1997 VL 385 IS 3 BP 523 EP 529 DI 10.1016/S0168-9002(96)00928-X PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WJ772 UT WOS:A1997WJ77200021 ER PT J AU Bieser, F Cooper, G Cwienk, W Eckardt, V Fessler, H Fischer, HG Gabler, F Gornicki, E Hearn, WE Heupke, W Irmscher, D Jacobs, P Kleinfelder, S Lindenstruth, V Machowski, B Marks, K Milgrome, O Mock, A Noggle, T Pimpl, W Poskanzer, AM Rauch, W Renfordt, R Ritter, HG Rohrich, D Rudolph, H Ruschmann, GW Schafer, E Seyboth, P Seyerlein, J Stock, R Sulimma, K Toy, M Vu, C Wenig, S Wieman, H Wright, ME AF Bieser, F Cooper, G Cwienk, W Eckardt, V Fessler, H Fischer, HG Gabler, F Gornicki, E Hearn, WE Heupke, W Irmscher, D Jacobs, P Kleinfelder, S Lindenstruth, V Machowski, B Marks, K Milgrome, O Mock, A Noggle, T Pimpl, W Poskanzer, AM Rauch, W Renfordt, R Ritter, HG Rohrich, D Rudolph, H Ruschmann, GW Schafer, E Seyboth, P Seyerlein, J Stock, R Sulimma, K Toy, M Vu, C Wenig, S Wieman, H Wright, ME TI Design and performance of TPC readout electronics for the NA49 experiment SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE electronics; heavy-ion physics; time projection chamber; data acquisition ID HEAVY-ION COLLISIONS AB Highly integrated readout electronics were developed and produced for the 182 000 channels of the four TPCs of the NA49 heavy-ion fixed target experiment at the CERN SPS. The large number of channels, the high packing density and required cost minimization led to the choice of a custom electronics system. The requirements, the design and the performance of the electronics components are described. C1 MAX PLANCK INST PHYS & ASTROPHYS,MUNICH,GERMANY. CERN,GENEVA,SWITZERLAND. UNIV FRANKFURT,FACHBEREICH PHYS,D-6000 FRANKFURT,GERMANY. INST PHYS NUCL,KRAKOW,POLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA. RP Bieser, F (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. NR 20 TC 9 Z9 9 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 FEB 1 PY 1997 VL 385 IS 3 BP 535 EP 546 DI 10.1016/S0168-9002(96)01029-7 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WJ772 UT WOS:A1997WJ77200023 ER PT J AU Shiue, CY Vallabhahosula, S Wolf, AP Dewey, SL Fowler, JS Schlyer, DJ Arnett, CD Zhou, YG AF Shiue, CY Vallabhahosula, S Wolf, AP Dewey, SL Fowler, JS Schlyer, DJ Arnett, CD Zhou, YG TI Carbon-11 labelled ketamine - Synthesis, distribution in mice and PET studies in baboons SO NUCLEAR MEDICINE AND BIOLOGY LA English DT Article DE baboon; ketamine; 2-(o-chlorophenyl)-2-(methylamino); mouse brain; [C-11]ketamine ID POSITRON EMISSION TOMOGRAPHY; COMPARATIVE PHARMACOLOGY; METABOLISM; RECEPTOR; BINDING; ISOMERS; RAT; INVITRO; ACID AB No carrier-added (NCA)[C-11](+/-)-ketamine (2a) and its errantiomers (+)-2b and (-)-2e were synthesized by methylation of the corresponding norketamine (1a-c) with [C-11]H3I in an overall radiochemical yield of 20% (EOB) with specific activities of 0.35-0.45 Ci/mu mole at EOB in a synthesis time of 40 min from EOB. Compound 2a was metabolized rapidly in mouse brain and labeled metabolites appeared in baboon plasma. PET studies of compounds 2a-c in a baboon showed that influx of compounds 2a-c into the brain was high for the first few min but radioactivity then declined rapidly. Although the retention of radioactivity in the baboon striatum was not significantly different for 2a-c 20 min post injection, graphical analysis of time-activity data for each enantiomer and for the racemate in baboon striatum suggested that (+)-ketamine may interact with receptors slightly more effectively than its (-)-enantiomer or racemate. However, due to its rapid metabolism in the brain and a similar uptake in the striatum and cerebellum, [C-11]ketamine may not be an ideal tracer for studying NMDA receptor with PET. (C) 1997 Elsevier Science Inc. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. MT SINAI MED CTR,NEW YORK,NY 10029. SHANGHAI MED UNIV,SHANGHAI 200032,PEOPLES R CHINA. FU NINDS NIH HHS [NS-15638, NS-15380] NR 28 TC 20 Z9 20 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0883-2897 J9 NUCL MED BIOL JI Nucl. Med. Biol. PD FEB PY 1997 VL 24 IS 2 BP 145 EP 150 DI 10.1016/S0969-8051(96)00186-2 PG 6 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WN448 UT WOS:A1997WN44800004 PM 9089707 ER PT J AU Bhalgat, MK Roberts, JC MercerSmith, JA Knotts, BD Vessella, RL Lavallee, DK AF Bhalgat, MK Roberts, JC MercerSmith, JA Knotts, BD Vessella, RL Lavallee, DK TI Preparation and biodistribution of copper-67-labeled porphyrins and porphyrin-A6H immunoconjugates SO NUCLEAR MEDICINE AND BIOLOGY LA English DT Article DE antibody delivery; renal cell carcinoma; copper-67; porphyrin chelators; targeting ID RENAL-CELL CARCINOMA; MONOCLONAL-ANTIBODY; COLORECTAL-CARCINOMA; RADIOTHERAPY; DOSIMETRY; FRAGMENTS; MECHANISM; THERAPY; ANTIGEN; MODEL AB The synthetic porphyrins, N-benzyl-5,10,15,20-tetrakis(4-carboxyphenyl)porphine (N-bzHTCPP) and N-4-nitrobenzyl-5-(4-carboxyphenyl)-10,15,20-tris(4-sulfophenyl) porphine (N-bzHCS(3)P), represent excellent radiocopper chelating agents that may find utility in antibody mediated diagnosis and/or therapy. N-bzHCS(3)P was conjugated to an anti-renal cell carcinoma (RCC) antibody, A6H, and labeled with copper 67. (CuCS3P)-Cu-67-A6H was studied for its biodistribution in human RCC xenograft bearing nude mice, along with the radiolabeled free porphyrins. The porphyrins resulted in tumor:blood ratios in the range of 3 to 4 after 48 h. The radiolabeled antibody achieved a tumor:blood ratio of over 16 after 45 h, indicating accumulation at the desired site. However, unwanted localization also occurred in the liver and spleen, which will have to be rectified before realizing the full potential of this approach. (C) 1997 Elsevier Science Inc. C1 UNIV UTAH,DEPT MED CHEM,SALT LAKE CITY,UT 84112. LOS ALAMOS NATL LAB,MED RADIOISOTOPES RES PROGRAM,LOS ALAMOS,NM 87545. UNIV WASHINGTON,DEPT UROL,SEATTLE,WA 98195. CUNY HUNTER COLL,NEW YORK,NY 10021. FU NCI NIH HHS [CA25427] NR 43 TC 17 Z9 17 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0883-2897 J9 NUCL MED BIOL JI Nucl. Med. Biol. PD FEB PY 1997 VL 24 IS 2 BP 179 EP 185 DI 10.1016/S0969-8051(96)00215-6 PG 7 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WN448 UT WOS:A1997WN44800008 PM 9089710 ER PT J AU Mackenzie, PB AF Mackenzie, PB TI Recent lattice results on the light quark masses SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID QCD AB I discuss old and new determinations of the light quark masses using lattice QCD. Most lattice results using various approximations can be fit together in a simple picture which is consistent with lower values than conventionally supposed: in the quenched approximation for the strange quark mass in the <(MS)over bar> scheme, <(m)over bar (s)>,(2 GeV) = 95(16) MeV, and for the average of the u and d quark masses, <(m)over bar (l)>(2 GeV) = 3.6(6) MeV. An estimate of the effects of light quark loops yields answers lower still: <(m)over bar (s)>,(2 GeV) in the range 54 - 92 MeV, and <(m)over bar (l)>(2 GeV) in the range 2.1 - 3.5 MeV. C1 FERMILAB NATL ACCELERATOR LAB, DEPT THEORET PHYS, BATAVIA, IL 60510 USA. RP UNIV TSUKUBA, CTR COMPUTAT PHYS, TSUKUBA, IBARAKI 305, JAPAN. NR 22 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 23 EP 29 DI 10.1016/S0920-5632(96)00596-8 PG 7 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900004 ER PT J AU Voyvodic, L AF Voyvodic, L TI Comparison of simulation results for giant air showers SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT IXth International Symposium on Very High Energy Cosmic Ray Interactions CY AUG 18-24, 1996 CL KARLSRUHE UNIV, KARLSRUHE, GERMANY HO KARLSRUHE UNIV AB Comparisions have been made between shower parameters from MOCCA simulations, featured in many Auger Project design studies and from results available from other simulations. Average values of electron and muon components in vertical proton showers are compared for depth of maximum, shearer sizes at sea level and particle densities at distance of 600 meters on the ground. Systematic differences are found, the differences increasing with proton energy. At 10(19) eV the MOCCA predictions, compared with recent simulations based on quark gluon string and other models, show considerably larger average depth of maximum and electron shower size at the ground, but about a factor of two smaller muon and electron densities at 600 meters from the core. These features, of particular interest for energy and composition determinations from ground arrays, are consistent with expectations for increasing inelasticities and transverse momenta in ultra high energy hadron-air interactions. RP Voyvodic, L (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 52B BP 142 EP 142 DI 10.1016/S0920-5632(96)00872-9 PG 1 WC Physics, Particles & Fields SC Physics GA WW405 UT WOS:A1997WW40500022 ER PT J AU Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Sugar, RL Toussaint, D Wingate, M AF Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Sugar, RL Toussaint, D Wingate, M TI Recent MILC spectrum results SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID LATTICE GAUGE-THEORIES AB We report on results from three spectrum calculations with staggered quarks: 1) a quenched calculation with the standard action for the gluons and quarks; 2) a quenched calculation with improved actions for both the gluons and quarks; and 3) a calculation with two flavors of dynamical quarks using the standard actions for the gluons and quarks. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. RP WASHINGTON UNIV, DEPT PHYS, 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; DeTar, Carleton/0000-0002-0216-6771; Rummukainen, Kari/0000-0003-2266-4716 NR 7 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 212 EP 215 DI 10.1016/S0920-5632(96)00617-2 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900025 ER PT J AU Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Sugar, B Toussaint, D Wingate, M AF Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Sugar, B Toussaint, D Wingate, M TI Exotic hybrid mesons with light quarks SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID QCD AB Hybrid mesons, made from a quark, an antiquark and gluons, can have quantum numbers inaccessible to conventional quark-antiquark states. Confirmation of such states would give information on the role of ''dynamical'' color in low energy QCD. We present preliminary results for hybrid meson masses using light Wilson valence quarks. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. FLORIDA STATE UNIV,SCRI,TALLAHASSEE,FL 32306. UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP Bernard, C (reprint author), WASHINGTON UNIV,DEPT PHYS,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; DeTar, Carleton/0000-0002-0216-6771; Rummukainen, Kari/0000-0003-2266-4716 NR 10 TC 20 Z9 20 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 228 EP 231 DI 10.1016/S0920-5632(96)00622-6 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900030 ER PT J AU Duncan, A Eichten, E Perrucci, S Thacker, H AF Duncan, A Eichten, E Perrucci, S Thacker, H TI Quenched chiral logs, the eta' mass, and the hairpin diagram SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID QCD AB Limits on the size of quenched chiral logs in the pion mass for Wilson fermions are investigated. The smallness of chiral logs is shown to be a result of the suppression of the hairpin diagram for small p(2), such that the value of the hairpin on the pion mass shell is much smaller than the physical m(eta')(2),. A direct calculation of the topological susceptibility from the same data gives m(eta'), approximate to 1 GeV. C1 FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. UNIV VIRGINIA, DEPT PHYS, CHARLOTTESVILLE, VA 22901 USA. RP UNIV PITTSBURGH, DEPT PHYS & ASTRON, PITTSBURGH, PA 15260 USA. NR 5 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 256 EP 258 DI 10.1016/S0920-5632(96)00629-9 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900037 ER PT J AU Venkataraman, L Kilcup, G Grandy, J AF Venkataraman, L Kilcup, G Grandy, J TI The staggered eta' with smeared operators SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB We present a refined calculation of the eta' mass using staggered fermions and Wuppertal smeared operators to suppress excited state contributions. We use quenched and dynamical configurations of size 16(3) x 32, with N-f = 0, N-f = 2 and N-f = 4, and compare our results with the expected theoretical forms from quenched, partially quenched, and unquenched chiral perturbation theory. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Venkataraman, L (reprint author), OHIO STATE UNIV,DEPT PHYS,174 W 18TH AVE,COLUMBUS,OH 43210, USA. NR 4 TC 7 Z9 7 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 FEB PY 1997 SU 53 BP 259 EP 261 DI 10.1016/S0920-5632(96)00630-5 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900038 ER PT J AU Kogut, JB Lagae, JF Sinclair, DK AF Kogut, JB Lagae, JF Sinclair, DK TI Manifestations of the axial anomaly in finite temperature QCD SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID LATTICE AB We compute the flavor singlet meson correlators and screening masses in quenched and N-f = 2 QCD at N-t = 8. The consequences of our results for the realization of the U-A(1) symmetry at finite T are discussed and an interpretation of our measurements in terms of the behaviour of the low lying fermionic modes is proposed. C1 ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. RP UNIV ILLINOIS, DEPT PHYS, 1110 W GREEN ST, URBANA, IL 61801 USA. NR 10 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 269 EP 271 DI 10.1016/S0920-5632(96)00633-0 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900041 ER PT J AU Kogut, JB Sinclair, DK AF Kogut, JB Sinclair, DK TI QCD with chiral 4-fermion interactions (chi QCD) SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID ALGORITHMS AB Lattice QCD with staggered quarks is augmented by the addition of a chiral 4-fermion interaction. The Dirac operator is now non-singular at m(q) = 0, decreasing the computing requirements for light quark simulations by at least an order of magnitude. We present preliminary results from simulations at finite and sere temperatures for m(q) = 0, with and without gauge fields. C1 ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. RP Kogut, JB (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. NR 9 TC 8 Z9 7 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 FEB PY 1997 SU 53 BP 272 EP 274 DI 10.1016/S0920-5632(96)00634-2 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900042 ER PT J AU Onogi, T ElKhadra, AX Gough, BJ Hockney, GM Kronfeld, AS Mackenzie, PB Mertens, BP Simone, JN AF Onogi, T ElKhadra, AX Gough, BJ Hockney, GM Kronfeld, AS Mackenzie, PB Mertens, BP Simone, JN TI The light quark masses with an O(a)-improved action SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID QCD AB we present the recent Fermilab calculations of the masses of the light quarks, using tadpole-improved Sheikholeslami-Wohlert (SW) quarks. Sources of systematic errors are studied. Our final result for the average Light quark mass in the quenched approximation evaluated in the <(MS)over bar> scheme is <(m)over bar (q)>(2GeV) = 3.6 +/- 0.6 MeV. (See 2.3). C1 UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. FERMILAB NATL ACCELERATOR LAB, THEORY GRP, BATAVIA, IL 60510 USA. UNIV CHICAGO, DEPT PHYS, CHICAGO, IL 60637 USA. RP HIROSHIMA UNIV, DEPT PHYS, 1-3-1 KAGAMIYAMA, HIGASHIHIROSHIMA 739, JAPAN. NR 6 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 289 EP 291 DI 10.1016/S0920-5632(96)00639-1 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900047 ER PT J AU Gupta, R Bhattacharya, T AF Gupta, R Bhattacharya, T TI Light quark masses and the CP violation parameter epsilon'/epsilon SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB We present estimates of light quarks masses using lattice data. Our main results are based on a global analysis of all the published data for Wilson and Staggered fermions, both in the quenched approximation and with n(f) = 2 dynamical flavors. The Wilson and Staggered results agree after extrapolation to the continuum limit for both the n(f) = 0, 2 theories. Our best estimates, in the <(MS)over bar> scheme at scale 2 GeV, are (m) over bar = 3.2(4) MeV and m(s) = 90(20) MeV in the quenched approximation, and (m) over bar similar to 2.7 MeV and (m) over bar similar to 70 MeV for the n(f) = 2 theory. These estimates are significantly smaller than phenomenological estimates based on sum rules, but maintain the ratios predicted by chiral perturbation theory (chi PT). Along with the new estimates of 4-fermion operators, lower quark masses have a significant impact on the extraction of epsilon'/epsilon from the Standard Model. RP LOS ALAMOS NATL LAB, T8 GRP, MS B285, LOS ALAMOS, NM 87545 USA. RI Bhattacharya, Tanmoy/J-8956-2013 OI Bhattacharya, Tanmoy/0000-0002-1060-652X NR 8 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 292 EP 294 DI 10.1016/S0920-5632(96)00640-8 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900048 ER PT J AU Duncan, A Eichten, E Thacker, H AF Duncan, A Eichten, E Thacker, H TI Electromagnetic splittings and light quark masses SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB A method for computing electromagnetic properties of hadrons in lattice QCD is described. The electromagnetic field is introduced dynamically. using a noncompact formulation. Employing enhanced electric charges. the dependence of the pseudoscalar meson mass on the (anti)quark charges and masses can be accurately calculated. At beta = 5.7 with Wilson action, the pi(+) - pi(0) splitting is found to be 4.9(3) MeV. Using the measured K-0 - K+ splitting, we also find m(u)/m(d) = .512(6). Systematic errors are discussed. Preliminary results for vector meson splittings are also presented. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. UNIV VIRGINIA,DEPT PHYS,CHARLOTTESVILLE,VA 22901. RP Duncan, A (reprint author), UNIV PITTSBURGH,DEPT PHYS & ASTRON,PITTSBURGH,PA 15260, USA. NR 5 TC 6 Z9 6 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 FEB PY 1997 SU 53 BP 295 EP 298 DI 10.1016/S0920-5632(96)00641-X PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900049 ER PT J AU Duncan, A Eichten, E Thacker, H AF Duncan, A Eichten, E Thacker, H TI Electromagnetic structure of light baryons in lattice QCD SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB A method in which electromagnetic properties of hadrons are studied by direct simulation of dynamical photon effects is applied to the extraction of the isomultiplet structure of the octet baryons. Using 187 configurations at beta = 5.7 with Wilson action, and up and down quark masses determined from the meson spectrum, the nucleon splitting is found to be 1.55(+/-0.56 stat) MeV; the hyperon splittings are found to be Sigma(0) - Sigma(+) = 2.47 +/- 0.39, Sigma(-) - Sigma(0) = 4.63 +/- 0.36, Xi(-) - Xi(0) = 5.68 +/- 0.24 MeV. Estimated systematic corrections arising from finite volume and the quenched approximation are included in these results. C1 FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. UNIV VIRGINIA, DEPT PHYS, CHARLOTTESVILLE, VA 22901 USA. RP UNIV PITTSBURGH, DEPT PHYS & ASTRON, PITTSBURGH, PA 15260 USA. NR 7 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 299 EP 301 DI 10.1016/S0920-5632(96)00642-1 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900050 ER PT J AU Bernard, C Blum, T DeGrand, T DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Soni, A Sugar, R Toussaint, D Wingate, M AF Bernard, C Blum, T DeGrand, T DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Soni, A Sugar, R Toussaint, D Wingate, M TI Update on f(B) SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID QCD AB We describe the current status of the MILC collaboration computation of f(B), f(Bs), f(D), f(Ds) and their ratios. Progress over the past year includes: better statistics and plateaus at beta = 6.52 (quenched), beta = 5.6 (N-F = 2) and beta = 5.445 (N-F = 2), new runs with a wide range of dynamical quark masses at beta = 5.5 (N-F = 2), an estimate of the systematic errors due to the chiral extrapolation, and an improved analysis which consistently takes into account both the correlations in the data at every stage and the systematic effects due to changing fitting ranges. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. FLORIDA STATE UNIV, SCRI, TALLAHASSEE, FL 32306 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. RP WASHINGTON UNIV, DEPT PHYS, 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; DeTar, Carleton/0000-0002-0216-6771; Rummukainen, Kari/0000-0003-2266-4716 NR 11 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 358 EP 361 DI 10.1016/S0920-5632(96)00659-7 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900067 ER PT J AU Khan, AA Bhattacharya, T AF Khan, AA Bhattacharya, T TI B and B-c mesons with NRQCD and clover actions SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID NONRELATIVISTIC LATTICE QCD AB We present preliminary results from our study of the heavy-light spectrum and decay constants. For the heavy quark, we use NRQCD at various masses around and above the b quark mass. For the first time, the heavy quark action and the heavy-light current consistently include corrections at second order in the non-relativistic expansion, as well as the leading finite a corrections. The light quarks are simulated using a tadpole-improved Clover action at various masses in the strange and c quark region. C1 LOS ALAMOS NATL LAB, T8 GRP, LOS ALAMOS, NM 87545 USA. RP UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. RI Bhattacharya, Tanmoy/J-8956-2013 OI Bhattacharya, Tanmoy/0000-0002-1060-652X NR 6 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 368 EP 373 PG 6 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900070 ER PT J AU Bernard, C Blum, T DeGrand, T DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Sugar, R Toussaint, D Wingate, M AF Bernard, C Blum, T DeGrand, T DeTar, C Gottlieb, S Heller, UM Hetrick, J McNeile, C Rummukainen, K Sugar, R Toussaint, D Wingate, M TI Assorted weak matrix elements involving the bottom quark SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB As part of a larger project to estimate the f(B) decay constant, we are recalculating f(B)(static) using a variational smearing method in an effort to improve accuracy. Preliminary results for the static B-B parameter and HQET two point functions are also presented. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. FLORIDA STATE UNIV, SCRI, TALLAHASSEE, FL 32306 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. RP WASHINGTON UNIV, DEPT PHYS, ST LOUIS, MO 63130 USA. OI Hetrick, James/0000-0002-0740-2251; Heller, Urs M./0000-0002-2780-5584; Wingate, Matthew/0000-0001-6568-988X; DeTar, Carleton/0000-0002-0216-6771; Rummukainen, Kari/0000-0003-2266-4716 NR 15 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 374 EP 377 DI 10.1016/S0920-5632(96)00663-9 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900071 ER PT J AU Bernard, C Blum, T Soni, A AF Bernard, C Blum, T Soni, A TI SU(3) flavor breaking in hadronic matrix elements for B-(B)over-bar oscillations SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID B-MESONS; 4-FERMION OPERATORS; DECAY CONSTANTS; LATTICE AB We present an analysis, using quenched configurations at 6/g(2) = 5.7, 5.85, 6.0, and 6.3 of the matrix element M(hl) = [<(P)over bar (hl)>\<(h)over bar (gamma mu)>(1 - gamma(5))(1 - gamma(5))l\P-hl] for heavy-light pseudoscalar mesons. The results are extrapolated to the physical B meson states, B-0 and B-s(0). We directly compute the ratio M(bs)/M(bd), and obtain the preliminary result M(bs)/M(bd) = 1.54(13)(32). A precise value of this SU(3) breaking ratio is important for determining V-td once the mixing parameter x(s) for B-s(0) - <(B)over bar (0)(s)> is measured experimentally. We also determine values for the corresponding B parameters, B-bs(2GeV) = B-bd(2GeV) = 1.02(13), which we cannot distinguish in the present analysis. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. RP WASHINGTON UNIV, DEPT PHYS, ST LOUIS, MO 63130 USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 382 EP 385 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900073 ER PT J AU Simone, JN AF Simone, JN TI A look at lattice artifacts in weak matrix elements SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB Realistic estimates for systematic errors in weak matrix elements from the lattice are crucial for phenomenological applications. An important source of uncertainty is momentum dependent discretisation errors. Pseudoscalar meson leptonic decays provide a good laboratory to explore momentum dependent cutoff effects. C1 FERMILAB NATL ACCELERATOR LAB, THEORY GRP, BATAVIA, IL 60510 USA. NR 5 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 386 EP 388 DI 10.1016/S0920-5632(96)00666-4 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900074 ER PT J AU Mandula, JE Ogilvie, MC AF Mandula, JE Ogilvie, MC TI Non-perturbative renormalization of the lattice heavy quark classical velocity SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB We discuss the renormalization of the lattice formulation of the Heavy Quark Effective Theory (LHQET). In addition to wave function and composite operator renormalizations, on the lattice the classical velocity is also renormalized. The origin of this renormalization is the reduction of Lorentz (or O(4)) invariance to (hyper)cubic invariance. We present results of a new, direct lattice simulation of this finite renormalization, and compare the results to the perturbative (one loop) result. The simulation results are obtained with the use of a variationally optimized heavy-light meson operator, using an ensemble of lattices provided by the Fermilab ACP-MAPS collaboration. C1 WASHINGTON UNIV, DEPT PHYS, ST LOUIS, MO 63130 USA. RP US DOE, DIV HIGH ENERGY PHYS, WASHINGTON, DC 20585 USA. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 395 EP 397 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900077 ER PT J AU Kronfeld, AS AF Kronfeld, AS TI Binding energies in nonrelativistic field theories SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID LATTICE QCD AB Relativistic corrections communicate the binding energy of a bound state to its kinetic mass. This mechanism is reviewed and used to explain anomalous results of Collins, Edwards, Heller, and Sloan (hep-lat/9512026), which compared rest and kinetic masses of heavy-light mesons and quarkonia. RP FERMILAB NATL ACCELERATOR LAB, THEORET PHYS GRP, POB 500, BATAVIA, IL 60510 USA. OI Kronfeld, Andreas/0000-0003-2716-1149 NR 13 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 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 401 EP 404 DI 10.1016/S0920-5632(96)00671-8 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900079 ER PT J AU Bernard, C Blum, T DeTar, CE Gottlieb, S Heller, UM Hetrick, JE Karkkainen, L McNeile, C Rummukainen, K Sugar, RL Toussaint, D Wingate, M AF Bernard, C Blum, T DeTar, CE Gottlieb, S Heller, UM Hetrick, JE Karkkainen, L McNeile, C Rummukainen, K Sugar, RL Toussaint, D Wingate, M TI Thermodynamics for two flavor QCD SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID FINITE-TEMPERATURE; PHASE-TRANSITION; EQUATION AB We conclude our analysis of the N-t = 6 equation of state (EOS) for two flavor QCD, first described at last year's conference. We have obtained new runs at am(q) = 0.025 and improved runs at am(q) = 0.0125. The results are extrapolated to m(q) = 0, and we extract the speed of sound as well. We also present evidence for a restoration of the SU(2)xSU(2) chiral symmetry just above the crossover, but not of the axial U(1) chiral symmetry. C1 BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. NOKIA RES CTR, FIN-33721 TAMPERE, FINLAND. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. RP WASHINGTON UNIV, DEPT PHYS, 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; DeTar, Carleton/0000-0002-0216-6771; Rummukainen, Kari/0000-0003-2266-4716 NR 13 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 442 EP 445 DI 10.1016/S0920-5632(96)00683-4 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900091 ER PT J AU Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM McNeile, C Rummukainen, K Sugar, B Toussaint, D Wingate, M AF Bernard, C Blum, T DeGrand, TA DeTar, C Gottlieb, S Heller, UM McNeile, C Rummukainen, K Sugar, B Toussaint, D Wingate, M TI Finite temperature lattice QCD with clover fermions SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID WILSON QUARKS AB We report on our simulation of finite temperature lattice QCD with two flavors of O(a) Symanzik-improved fermions and O(a(2)) Symanzik-improved glue. Our thermodynamic simulations were performed on an 8(3) x 4 lattice, and we have performed complementary zero temperature simulations on an 8(3) x 16 lattice. We compare our results to those from simulations with two flavors of Wilson fermions and discuss the improvement resulting from use of the improved action. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV COLORADO,DEPT PHYS,BOULDER,CO 80309. UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112. INDIANA UNIV,DEPT PHYS,BLOOMINGTON,IN 47405. FLORIDA STATE UNIV,SUPERCOMP COMPUTAT RES INST,TALLAHASSEE,FL 32306. UNIV ARIZONA,DEPT PHYS,TUCSON,AZ 85721. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. RP Bernard, C (reprint author), WASHINGTON UNIV,DEPT PHYS,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; DeTar, Carleton/0000-0002-0216-6771; Rummukainen, Kari/0000-0003-2266-4716 NR 9 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 446 EP 448 DI 10.1016/S0920-5632(96)00684-6 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900092 ER PT J AU Grandy, J Kilcup, G AF Grandy, J Kilcup, G TI Effect of improving the lattice gauge action on QCD topology SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB We use lattice topology as a laboratory to compare the Wilson action (WA) with the Symanzik-Weisz (SW) action constructed from a combination of (1 x 1) and (1 x 2) Wilson loops, and the estimate of the renormalization trajectory (RT)[1] from a renormalization group transformation (RGT) which also includes higher representations of the (1 x 1) loop. Topological charges are computed using the geometric (Luscher's) and plaquette methods on the uncooled lattice, and also by using cooling to remove ultraviolet artifacts. We show that as the action improves by approaching the RT, the topological charges for individual configurations computed using these three methods become more highly correlated, suggesting that artificial lattice renormalizations to the topological susceptibility can be suppressed by improving the action. C1 OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. RP LAWRENCE LIVERMORE NATL LAB, POB 808, L-170, LIVERMORE, CA 94551 USA. NR 9 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 560 EP 563 DI 10.1016/S0920-5632(96)00718-9 PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900126 ER PT J AU Bodwin, GT AF Bodwin, GT TI A lattice formulation of chiral gauge theories SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV AB We present a method for implementing gauge theories of chiral fermions on the lattice. RP Bodwin, GT (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 3 TC 1 Z9 1 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 FEB PY 1997 SU 53 BP 644 EP 646 DI 10.1016/S0920-5632(96)00742-6 PG 3 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900150 ER PT J AU Creutz, M Tytgat, M AF Creutz, M Tytgat, M TI Species doubling and effective Lagrangians SO NUCLEAR PHYSICS B LA English DT Article; Proceedings Paper CT XIV International Conference on Lattice Gauge Theory CY JUN 04-08, 1996 CL WASHINGTON UNIV, ST LOUIS, MO SP Intel Corp, US DOE, Washington Univ Coll Arts Sci, US Natl Sci Fdn, Parks Coll, St Louis Univ, Cray Res Corp HO WASHINGTON UNIV ID CHIRAL GAUGE-THEORIES; SYMMETRY-BREAKING; CURRENT-ALGEBRA; LATTICE; FERMIONS; CONSTRUCTION AB Coupling gauge fields to the chiral currents from an effective Lagrangian for pseudoscalar mesons naturally gives rise to a species doubling phenomenon similar to that seen with fermionic fields in lattice gauge theory. RP BROOKHAVEN NATL LAB, DEPT PHYS, POB 5000, UPTON, NY 11973 USA. NR 30 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD FEB PY 1997 SU 53 BP 651 EP 654 DI 10.1016/S0920-5632(96)00744-X PG 4 WC Physics, Particles & Fields SC Physics GA WH969 UT WOS:A1997WH96900152 ER PT J AU Broadhead, BL Tang, JS Childs, RL Parks, CV Taniuchi, H AF Broadhead, BL Tang, JS Childs, RL Parks, CV Taniuchi, H TI Evaluation of shielding analysis methods in spent-fuel cask environments SO NUCLEAR TECHNOLOGY LA English DT Article DE spent-fuel casks; radiation shielding; dose rate measurements AB The three-dimensional Monte Carlo code MORSE-SGC, as implemented in the SCALE system calculational sequence SAS4, is applied to the analysis of a series of simple geometry benchmark experiments and prototypic spent-fuel storage cask measurements. The simple geometry experiments were performed in Japan and at the General Electric-Morris Operation facility; the cask measurements were performed at the Idaho National Engineering Laboratory. The quantification of uncertainties in a typical shielding analysis process for transport/storage casks can be accomplished by comparison of consistent trends between calculated and measured dose rate quantities in both benchmark and prototypic environments. Benchmark results typically measure the validity of cross-section data and computer code adequacy; prototypic environments, however, generally measure the overall validity of the calculational procedure. A total of five storage cask problems and two simple geometry problems were analyzed to determine the expected accuracies of computational analyses using well-established source-generation and Monte Carlo codes. The general trends seen in this work are in agreement within 30% or better with the measurements for neutron dose rates along the cask side, lid, and bottom. The gamma-ray dose rates with substantial contributions from the top endfitting, plenum, and bottom endfitting regions also are in good agreement. Based on the latest results, gamma-ray dose rate calculations with major contributions due to the active fuel region show a consistent factor of 1.6 overprediction of the measured quantities for casks with iron and concrete shields. Major uncertainties exist in the quantification of Co-59 concentrations in endfitting hardware materials. The results presented support the accuracy of source generation methods and dose estimation methods in these regions given accurate impurity characterizations. Thus, it is felt that the practice of using upper bounds for Co-59 initial concentrations should ensure conservative cask designs. Fortunately, the gamma-ray dose discrepancies seen along the sides of both the iron and concrete cask surfaces are overpredictions. The reason for overprediction is not fully known. Even though these overpredictions are not clearly understood, the trends observed, combined with some degree of code and data testing using these or similar benchmark measurements, should inspire confidence in the shielding results for a shipping/storage package. RP Broadhead, BL (reprint author), OAK RIDGE NATL LAB,COMPUTAT PHYS & ENGN DIV,POB 2008,OAK RIDGE,TN 37831, USA. OI Parks, Cecil/0000-0003-0323-8447 NR 28 TC 4 Z9 4 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0029-5450 J9 NUCL TECHNOL JI Nucl. Technol. PD FEB PY 1997 VL 117 IS 2 BP 206 EP 222 PG 17 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WD510 UT WOS:A1997WD51000008 ER PT J AU Torres, S Cayon, L MartinezGonzalez, E Sanz, JL AF Torres, S Cayon, L MartinezGonzalez, E Sanz, JL TI Testing cosmological models with COBE data SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA B-GENERAL PHYSICS RELATIVITY ASTRONOMY AND MATHEMATICAL PHYSICS AND METHODS LA English DT Article; Proceedings Paper CT 4th Italian-Korean Meeting on Relativistic Astrophysics CY JUL 09-15, 1995 CL ROME, ITALY ID DIFFERENTIAL MICROWAVE RADIOMETER; POWER-SPECTRUM; DENSITY-FLUCTUATIONS; SKY MAPS; ANISOTROPY; IMPRINT AB We test cosmological models with Omega < 1 using the COBE two-year cross-correlation function by means of a maximum-likelihood test with Monte Carlo realizations of several Omega models. Assuming a Harrison-Zel'dovich primordial power spectrum with amplitude proportional to Q, it is found that there is a large region in the (Omega, Q), parameter space that fits the data equally well. We find that the flatness of the universe is not implied by the data. A summary of other analyses of COBE data to constrain the shape of the primordial spectrum is presented. C1 CTR INT FIS,BOGOTA,COLOMBIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. UNIV CANTABRIA,CSIC,INST FIS CANTABRIA,E-39005 SANTANDER,SPAIN. RP Torres, S (reprint author), UNIV NACL,ASTRON OBSERV,AA 49490,BOGOTA,COLOMBIA. RI Martinez-Gonzalez, Enrique/E-9534-2015 OI Martinez-Gonzalez, Enrique/0000-0002-0179-8590 NR 26 TC 0 Z9 0 U1 0 U2 0 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 0369-3554 J9 NUOVO CIMENTO B JI Nouvo Cimento Soc. Ital. Fis. B-Gen. Phys. Relativ. Astron. Math. Phys. Methods PD FEB-MAR PY 1997 VL 112 IS 2-3 BP 525 EP 529 PG 5 WC Physics, Multidisciplinary SC Physics GA XC671 UT WOS:A1997XC67100035 ER PT J AU Beck, U Yang, P Metzger, TH Peisl, J Falta, J Materlik, G Rupp, T Baumgartner, H Eisele, I Patel, JR AF Beck, U Yang, P Metzger, TH Peisl, J Falta, J Materlik, G Rupp, T Baumgartner, H Eisele, I Patel, JR TI Ge delta layer in Si(100) characterized by X-ray reflectivity, grazing incidence diffraction and standing-wave measurements SO NUOVO CIMENTO DELLA SOCIETA ITALIANA DI FISICA D-CONDENSED MATTER ATOMIC MOLECULAR AND CHEMICAL PHYSICS FLUIDS PLASMAS BIOPHYSICS LA English DT Article; Proceedings Paper CT 3rd European Symposium on X-ray Topography and High-Resolution X-ray Diffraction (X-TOP 96) CY APR 22-24, 1996 CL PALERMO, ITALY ID SURFACE; SUPERLATTICES; SILICON AB We report on the structural characterization of a Si-capped MBE-grown Ge delta layer of monolayer thickness on Si (100). We combined X-ray standing wave, X-ray reflectivity and grazing incidence diffraction measurements. X-ray standing wave measurements provide a precise, model-independent determination of the atomic positions of the Ge atoms in the delta layer. Results for the (400) and (220) Si reflections give coherent positions of 1.05+/-0.02 and 1.03+/-0.02, respectively. The coherent fraction is 0.89+/-0.02 in both cases, indicating that Ge is placed on substitutional sites with a lattice expansion perpendicular to the substrate surface, consistent viith pseudomorphic growth. This measured lattice expansion has been used to estimate a Ge content of less than or equal to 64% for the delta layer. X-ray reflectivity measurements in the vicinity of the critical angle of total reflection Fender a cap layer thickness of 164+/-5 Angstrom and a surface roughness of 9+/-1 Angstrom Grazing incidence diffraction measurements (GID) at the (022) in-plane reflection show intensity oscillations along the diffraction rod. Model calculations using kinematic scattering theory give layer thicknesses and roughnesses consistent with the reflectivity results. Furthermore they confirm the preservation of the lateral lattice parameter expected for pseudomorphic growth and are consistent with the delta-layer stoichiometry determined by XSW. C1 DESY,HAMBURGER SYNCHROTRONSTRAHLUNGSLAB HASYLAB,D-22603 HAMBURG,GERMANY. UNIV MUNICH,FAK ELEKTROTECH,INST PHYS,D-85577 NEUBIBERG,GERMANY. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,SSRL,STANFORD,CA 94309. RP Beck, U (reprint author), UNIV MUNICH,SEKT PHYS,GESCHWISTER SCHOLL PL 1,D-80539 MUNICH,GERMANY. RI Yang, Ping/C-5612-2008; Falta, Jens/F-4821-2016 OI Falta, Jens/0000-0002-4154-822X NR 23 TC 1 Z9 1 U1 0 U2 1 PU EDITRICE COMPOSITORI BOLOGNA PI BOLOGNA PA VIA STALINGRADO 97/2, I-40128 BOLOGNA, ITALY SN 0392-6737 J9 NUOVO CIMENTO D JI Nuovo Cimento Soc. Ital. Fis. D-Condens. Matter At. Mol. Chem. Phys. Fluids Plasmas Biophys. PD FEB-APR PY 1997 VL 19 IS 2-4 BP 403 EP 410 PG 8 WC Physics, Multidisciplinary SC Physics GA XJ003 UT WOS:A1997XJ00300035 ER PT J AU With, KA Gardner, RH Turner, MG AF With, KA Gardner, RH Turner, MG TI Landscape connectivity and population distributions in heterogeneous environments SO OIKOS LA English DT Article ID SPATIAL-DISTRIBUTION; FRACTAL LANDSCAPES; MOVEMENT PATTERNS; ECOLOGY; COEXISTENCE; HABITAT; MODELS AB Landscape connectivity refers to the functional relationship among habitat patches, owing to the spatial contagion of habitat and the movement responses of organisms to landscape structure. Heterogeneous landscapes provide a particular challenge for modelling population-level responses to habitat fragmentation, because individuals may be utilizing multiple habitats to varying degrees across the landscape. We apply neutral landscape models to understand how species' habitat affinities interacted with landscape structure (i.e., habitat abundance, distribution, and quality as measured by carrying capacity) to affect the redistribution of individuals. Two types of neutral models are presented: random maps, in which the distribution of habitat is spatially independent and fractal maps, in which habitat exhibits an intermediate level of spatial dependence. The neutral landscapes comprised varying proportions of three habitat types, for which species exhibited a preference gradient (high, medium, low). We performed a series of simulation experiments as a factorial design of parameter states to tease apart the underlying factors responsible for population distributional patterns (random vs clumped) in spatially complex mosaics. Landscape connectivity is a threshold phenomenon, in which even a minimal loss of habitat near the critical threshold (p(c)) is likely to disconnect the landscape, and which may have consequences for population distributions. The exact value of p(c) depends upon the spatial arrangement of habitat; fractal landscapes exhibited connectivity across a greater range of habitat abundance (p) than random maps (fractal p(c) = 0.29-0.50, random p(c) = 0.59). Although the spatial arrangement of habitat (random vs fractal) was the most important determinant of population distributional patterns, different landscape factors were important in structuring populations in the two types of maps. The relative abundance of habitat had the greatest effect on populations in random landscapes, whereas scale-dependent patterns were evident in fractal landscapes. At fine scales, population dispersion was determined by habitat abundance in both random and fractal maps, although populations were more aggregated (as measured by Morisita's Index, I-m) at this scale in random landscapes. But at coarse scales on fractal maps, population distribution was primarily influenced by species' habitat affinities. Assessment of the independent effects of habitat affinity and habitat carrying capacity on population distributions revealed that the differential interaction of species with landscape structure (i.e., different residence probabilities in each habitat type) was the primary determinant of distributional patterns. Neutral landscape models thus provide a useful tool for determining the relative importance of various components of landscape structure that affect population distributions. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RI Turner, Monica/B-2099-2010; With, Kimberly/J-5124-2014 OI With, Kimberly/0000-0001-5570-1515 NR 52 TC 323 Z9 341 U1 13 U2 135 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0030-1299 J9 OIKOS JI Oikos PD FEB PY 1997 VL 78 IS 1 BP 151 EP 169 DI 10.2307/3545811 PG 19 WC Ecology SC Environmental Sciences & Ecology GA WJ109 UT WOS:A1997WJ10900018 ER PT J AU Nguyen, HT Shore, BW Bryan, SJ Britten, JA Boyd, RD Perry, MD AF Nguyen, HT Shore, BW Bryan, SJ Britten, JA Boyd, RD Perry, MD TI High-efficiency fused-silica transmission gratings SO OPTICS LETTERS LA English DT Article ID SURFACE-RELIEF GRATINGS; NATIONAL-IGNITION-FACILITY; DIFFRACTION CHARACTERISTICS; PHOTORESIST AB We describe the design, fabrication, and performance of high-efficiency transmission gratings fabricated in bulk fused silica for use in high-power ultraviolet laser systems. The gratings exhibit a diffraction efficiency of 94% in order m = -1 and st damage threshold greater than 13 J/cm(2) for 3-ns pulses at 351 nm. Model calculations and experimental measurements are in good agreement. (C) 1997 Optical Society of America RP Nguyen, HT (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-439,LIVERMORE,CA 94550, USA. NR 18 TC 53 Z9 55 U1 2 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD FEB 1 PY 1997 VL 22 IS 3 BP 142 EP 144 DI 10.1364/OL.22.000142 PG 3 WC Optics SC Optics GA WE376 UT WOS:A1997WE37600002 PM 18183129 ER PT J AU Pint, BA Treska, M Hobbs, LW AF Pint, BA Treska, M Hobbs, LW TI The effect of various oxide dispersions on the phase composition and morphology of Al2O3 scales grown on beta-NiAl SO OXIDATION OF METALS LA English DT Article DE beta-NiAl; oxide dispersion; reactive elements; theta-Al2O3, phase transformation ID HIGH-TEMPERATURE OXIDATION; ALUMINA CATALYST SUPPORTS; THERMAL-STABILITY; ALLOYS; TRANSFORMATION; MECHANISM; LANTHANUM; BEHAVIOR AB A series of oxide-dispersed beta-NiAl alloys were oxidized in order to explore the effect of various cation dopants on the theta-alpha phase transformation in the Al2O3 scale and the effect of phase composition on the scale microstructure. Larger ions such as Y, Zr, La, and Hf appeared to slow the theta- to alpha-Al2O3 phase transformation, while a smaller ion, Ti, appeared to accelerate the transformation. C1 MIT,HH UHLIG CORROS LAB,CAMBRIDGE,MA 02139. RP Pint, BA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Pint, Bruce/A-8435-2008 OI Pint, Bruce/0000-0002-9165-3335 NR 37 TC 111 Z9 117 U1 1 U2 20 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0030-770X J9 OXID MET JI Oxid. Met. PD FEB PY 1997 VL 47 IS 1-2 BP 1 EP 20 DI 10.1007/BF01682369 PG 20 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA WF081 UT WOS:A1997WF08100001 ER PT J AU Slone, DM Rodrigue, GH AF Slone, DM Rodrigue, GH TI Efficient biased random bit generation for parallel lattice gas simulations SO PARALLEL COMPUTING LA English DT Article DE lattice gas methods; random bit generation; Burgers' equation; BBN TC2200; CRAY 90; performance; implementation ID RANDOM NUMBER GENERATOR; COMPUTERS; EQUATION AB Lattice gas methods are often used to model the kinetics of a variety of diffusive systems, One of the main advantages of these methods is the ease at which they can be parallelized using simple bit vector operations, However, to describe the kinetics of the lattice gas in a randomly biased fashion, it is necessary to efficiently generate a randomly biased bit vector, If one generates a random floating point number per bit, then this is very costly, In this paper, an efficient algorithm is developed that leads to a fully bit vector implementation of a lattice gas automation while significantly reducing the amount of needed generated random floating point numbers, The bit vector algorithm using the new random biased bit vector algorithm is tested on a lattice gas method whose solution is modeled by the solution of the 1-D Burgers' equation, This new lattice gas method is then implemented on the BBN TC2200 and CRAY 90 parallel processors. C1 UNIV CALIF DAVIS,DEPT APPL SCI,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 25 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-8191 J9 PARALLEL COMPUT JI Parallel Comput. PD FEB PY 1997 VL 22 IS 12 BP 1597 EP 1620 DI 10.1016/S0167-8191(96)00060-9 PG 24 WC Computer Science, Theory & Methods SC Computer Science GA WK688 UT WOS:A1997WK68800003 ER PT J AU Ross, FM Oskam, G Searson, PC Macaulay, JM Liddle, JA AF Ross, FM Oskam, G Searson, PC Macaulay, JM Liddle, JA TI Crystallographic aspects of pore formation in gallium arsenide and silicon SO PHILOSOPHICAL MAGAZINE A-PHYSICS OF CONDENSED MATTER STRUCTURE DEFECTS AND MECHANICAL PROPERTIES LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; N-TYPE SILICON; POROUS SILICON; ANODIC-DISSOLUTION; HYDROGEN TERMINATION; FORMATION MECHANISM; SI(100) SURFACES; SI(111) SURFACES; GAAS; HF AB The structure of porous layers formed in n-type GaAs is characterized and compared with the more familiar structure of porous n-type Si. Pores in n-type GaAs run in [111]a directions and have triangular or hexagonal cross-sections; their size and degree of branching depend on the doping level and current density. The characteristic differences between porous GaAs and porous Si are explained by a model in which we consider the bonding configuration of atoms on steps, kinks and terraces on the interior of the pore and the spatial distribution of the rate-limiting electrochemical reactions. C1 JOHNS HOPKINS UNIV, DEPT MAT SCI & ENGN, BALTIMORE, MD 21218 USA. SILICON VIDEO CORP, SAN JOSE, CA 95119 USA. AT&T BELL LABS, MURRAY HILL, NJ 07974 USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, NATL CTR ELECTRON MICROSCOPY, BERKELEY, CA 94720 USA. RI Searson, Peter /A-3311-2010; Schaff, William/B-5839-2009; Liddle, James/A-4867-2013; Oskam, Gerko/D-1768-2013; OI Liddle, James/0000-0002-2508-7910; Searson, Peter/0000-0002-5417-0828 NR 60 TC 27 Z9 27 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0141-8610 J9 PHILOS MAG A JI Philos. Mag. A-Phys. Condens. Matter Struct. Defect Mech. Prop. PD FEB PY 1997 VL 75 IS 2 BP 525 EP 539 PG 15 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Physics, Applied; Physics, Condensed Matter SC Materials Science; Metallurgy & Metallurgical Engineering; Physics GA WH401 UT WOS:A1997WH40100015 ER PT J AU Jia, QX Zhou, DS Foltyn, SR Wu, XD Findikoglu, AT Smith, JL AF Jia, QX Zhou, DS Foltyn, SR Wu, XD Findikoglu, AT Smith, JL TI Microstructure of Ba0.5Sr0.5TiO3 thin films on (100)LaAlO3 with SrRuO3 as electrodes SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID ELECTRICAL-PROPERTIES; LASER-ABLATION; (BA AB Using pulsed-laser deposition, we grew quaternary Ba0.5Sr0.5TiO3 thin films heteroepitaxially on (100) LaAlO3 substrates with conductive SrRuO3 as a bottom electrode. The microstructure of this multilayer of Ba0.5Sr0.5TiO3/SrRuO3/LaAlO3, was characterized by X-ray diffraction and cross-sectional transmission electron microscopy. The heteroepitaxial growth relationship was found to be (h00)(Ba0.5Sr0.5TiO3)parallel to(00l)(SrRuO3)parallel to(h00)(LaAlO3) and [110](Ba0.5Sr0.5TiO3)parallel to [100](SrRuO3)parallel to[110](LaAlO3). The high dielectric constant of the crystalline Ba0.5Sr0.5TiO3 thin films and the low leakage current of the Ba0.5Sr0.5TiO3 film sandwiched between a top Au and bottom SrRuO3 electrodes are attributed to the structural perfection of the films and the clean interfaces between layers. RP Jia, QX (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MAIL STOP G755,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 17 TC 4 Z9 5 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD FEB PY 1997 VL 75 IS 2 BP 261 EP 269 DI 10.1080/13642819708202314 PG 9 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA WH402 UT WOS:A1997WH40200007 ER PT J AU Pinhero, PJ Chang, SL Anderegg, JW Thiel, PA AF Pinhero, PJ Chang, SL Anderegg, JW Thiel, PA TI Effect of water on the surface oxidation of an Al-Pd-Mn quasicrystal SO PHILOSOPHICAL MAGAZINE B-PHYSICS OF CONDENSED MATTER STATISTICAL MECHANICS ELECTRONIC OPTICAL AND MAGNETIC PROPERTIES LA English DT Article ID QUASI-CRYSTALLINE COATINGS; SINGLE-GRAIN; ADSORPTION; ALLOYS; PHOTOELECTRON; ALUMINUM; AL(111); PHASE; H2O AB X-ray photoelectron spectroscopy is used to determine the effect of water on the oxidation of a quasicrystalline alloy at room temperature. We use a single-grain sample, oriented with the fivefold axis perpendicular to the surface plane, and with nominal bulk composition Al70Pd21Mn9. We compare the oxide which forms upon exposure to four basic environments: pure oxygen in ultrahigh vacuum, ambient air, humid air and liquid water. These environments are increasingly aggressive toward the alloy, as judged by the number of alloy constituents oxidized and by the thickness of the oxide layer. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP Pinhero, PJ (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011, USA. NR 27 TC 33 Z9 33 U1 0 U2 4 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0141-8637 J9 PHILOS MAG B JI Philos. Mag. B-Phys. Condens. Matter Stat. Mech. Electron. Opt. Magn. Prop. PD FEB PY 1997 VL 75 IS 2 BP 271 EP 281 DI 10.1080/13642819708202315 PG 11 WC Materials Science, Multidisciplinary; Mechanics; Physics, Applied; Physics, Condensed Matter SC Materials Science; Mechanics; Physics GA WH402 UT WOS:A1997WH40200008 ER PT J AU Cialella, AT Dubayah, R Lawrence, W Levine, E AF Cialella, AT Dubayah, R Lawrence, W Levine, E TI Predicting soil drainage class using remotely sensed and digital elevation data SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID LEAF-AREA INDEX; LAND-COVER CLASSIFICATION; REGRESSION TREE ANALYSIS; SATELLITE DATA; VEGETATION; RADIATION; MODEL; MAINE AB Soil drainage strongly affects the patterns and processes of ecosystems, including biomass production, vegetation community distribution, soil development, aeration, hydrologic processes, and trace gas fluxes. To obviate the need for extensive field surveys, we present a technique to use a remotely sensed optical image and digital elevation data to predict soil drainage class at a 6- by 4-km research site in a mixed conifer forest in Howland, Maine. Elevation, detrended elevation, slope, aspect, and flow accumulation were determined from a 10-m resolution digital elevation model (DEM) of the site. Normalized Difference Vegetation Index (NDVI) data derived from the Advanced Visible and Infrared Imaging Spectrometer (AVIRIS) were used to represent differences in vegetation cover. Classification tree analysis predicted soil drainage class with an average of 78 percent accuracy. RP Cialella, AT (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,BLDG 490D,UPTON,NY 11973, USA. NR 37 TC 26 Z9 27 U1 0 U2 3 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD FEB PY 1997 VL 63 IS 2 BP 171 EP 178 PG 8 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA WG253 UT WOS:A1997WG25300006 ER PT J AU Arko, AJ Joyce, JJ Andrews, AB Thompson, JD Smith, JL Moshopoulou, E Fisk, Z Menovsky, AA Canfield, PC Olson, CG AF Arko, AJ Joyce, JJ Andrews, AB Thompson, JD Smith, JL Moshopoulou, E Fisk, Z Menovsky, AA Canfield, PC Olson, CG TI Electronic structure of heavy fermions: Narrow temperature-independent bands SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE heavy electron system; photoemission; electronic band structure ID SPECTROSCOPIC EVIDENCE; PHOTOEMISSION SPECTRA; SYSTEMS; UPT3; FEATURES; STATE; UIR3 AB The electronic structure of both Ce and U heavy fermions appears to consist of extremely narrow temperature independent bands. There is no evidence from ARPES data reported here for a collective phenomenon normally referred to as the Kondo resonance. In uranium compounds a small dispersion of the bands is easily measurable. C1 FLORIDA STATE UNIV,NHMFL,TALLAHASSEE,FL 32306. UNIV AMSTERDAM,NAT KUNDIG LAB,NL-1018 XE AMSTERDAM,NETHERLANDS. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Arko, AJ (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI Canfield, Paul/H-2698-2014 NR 25 TC 25 Z9 25 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 16 EP 21 DI 10.1016/S0921-4526(96)00534-0 PG 6 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300004 ER PT J AU Yatskar, A Beyermann, WP Movshovich, R Canfield, PC Panchula, A Budko, SL AF Yatskar, A Beyermann, WP Movshovich, R Canfield, PC Panchula, A Budko, SL TI Unexpected heavy-electron behavior at low temperatures in PrInAg2 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE heavy electron system; quadrupolar Kondo effect; Kondo effect; PrInAg2 ID KONDO; ALLOYS AB Specific heat, magnetic susceptibility, and electrical resistivity were measured as a function of temperature in polycrystalline PrInAg2. A broad peak, similar to a conventional Kondo anomaly, occurs in the specific heat at 400 mK. Below the peak, an enhanced linear contribution is observed with a Sommerfeld coefficient of similar to 6.5 J/mol K-2. This is the first Pr-based compound to display heavy-fermion behavior, and it has a Kondo temperature of similar to 1 K. Inelastic -neutron-scattering experiments by Galera et al. found that the non-Kramers doublet (Gamma(3)) in PrInAg2 is the ground state with a first excited level at 5.9 meV. Since the ground slate does not have a magnetic moment, our results point to the possibility of a new type of interaction between the conduction electrons and the quadrupolar moments of the localized 4f electrons. The magnetic susceptibility follows a Curie-Weiss law above similar to 50 K with an effective moment of 3.67 mu(B). At low temperatures, the susceptibility falls below simple Curie-Weiss behavior, and it has a value close to that estimated for a Van Vleck contribution with the crystal electric field levels observed in neutron scattering. The electrical resistivity monotonically decreases with temperature and then saturates below similar to 10 K. A weak decrease is observed in the resistivity around 1 K which is consistent with the small Kondo temperature. C1 UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. AMES LAB,AMES,IA 50011. IOWA STATE UNIV,AMES,IA 50011. RI Canfield, Paul/H-2698-2014 NR 10 TC 5 Z9 5 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 FEB PY 1997 VL 230 BP 46 EP 48 DI 10.1016/S0921-4526(97)81582-7 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300011 ER PT J AU Schmiedeshoff, GM Torikachvili, MS Lacerda, A Buford, CM Smith, JL AF Schmiedeshoff, GM Torikachvili, MS Lacerda, A Buford, CM Smith, JL TI Linear and nonlinear magnetic susceptibility of U1-xThxBe13 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE U1-xThxBe13; heavy electron system; Kondo effect; magnetic susceptibility; high magnetic field ID UBE13 AB We report measurements of the isothermal magnetization of U1-xThxBe13 at 2.5 K, in fields to 18 T, on samples where 0 less than or equal to x less than or equal to 1. Linear (chi(1)) and nonlinear (chi(3)) contributions to the susceptibility are extracted from the data and studied as a function of thorium concentration x. We find chi(3) to be independent of x to about x = 0.9 while chi(1) shows an upturn as x --> 1, an upturn which we interpret as a reduction in a cooperative Kondo like compensation of the uranium magnetic moments. C1 LOS ALAMOS NATL LAB,NATL HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. SAN DIEGO STATE UNIV,DEPT PHYS,SAN DIEGO,CA 92182. N CAROLINA AGR & TECH STATE UNIV,DEPT PHYS,GREENSBORO,NC 27411. RP Schmiedeshoff, GM (reprint author), OCCIDENTAL COLL,DEPT PHYS,LOS ANGELES,CA 90041, USA. NR 3 TC 1 Z9 1 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 56 EP 58 DI 10.1016/S0921-4526(96)00544-3 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300014 ER PT J AU Mentink, SAM Amitsuka, H deVisser, A Slanic, Z Belanger, DP Neumeier, JJ Thompson, JD Menovsky, AA Mydosh, JA Mason, TE AF Mentink, SAM Amitsuka, H deVisser, A Slanic, Z Belanger, DP Neumeier, JJ Thompson, JD Menovsky, AA Mydosh, JA Mason, TE TI Thermodynamic study of the magnetic phase transition in UNi4B SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE UNi4B; specific heat; thermal expansion; magnetic phase transition; phase diagram AB We investigate the magnetic phase transition in UNi4B by specific heat, c(T), thermal expansion and resistivity under pressure. These experiments reveal that the hexagonal symmetry is not broken at T-N = 20 K, and predicts a hydrostatic pressure dependence of T-N of - 29 mK/kbar, close to the result from resistivity. The anomalous upturn of c/T to 470 mJ/mol K-2 at 0.4 K is reduced to 160 mJ/mol K-2 in 16T parallel to b-axis. The specific heat critical exponent alpha = - 0.15(2) suggests 3D Heisenberg universality in zero field. C1 UNIV AMSTERDAM,VAN DER WAALS ZEEMAN LAB,NL-1012 WX AMSTERDAM,NETHERLANDS. HOKKAIDO UNIV,DEPT PHYS,SAPPORO,HOKKAIDO 060,JAPAN. UNIV CALIF SANTA CRUZ,DEPT PHYS,SANTA CRUZ,CA 95064. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LEIDEN UNIV,KAMERLINGH ONNES LAB,NL-2300 RA LEIDEN,NETHERLANDS. RP Mentink, SAM (reprint author), UNIV TORONTO,DEPT PHYS,60 ST GEORGE ST,TORONTO,ON M5S 1A7,CANADA. RI Amitsuka, Hiroshi/K-8539-2012; Mason, Thomas/M-5809-2014 OI Mason, Thomas/0000-0003-1880-3971 NR 7 TC 2 Z9 2 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 108 EP 110 DI 10.1016/S0921-4526(96)00561-3 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300031 ER PT J AU Tang, J Gschneidner, KA AF Tang, J Gschneidner, KA TI Antiferromagnetic ordering in CeHg3 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE CeHg3; antiferromagnet order; specific heat; heat capacity AB CeHg3 was found to undergo an antiferromagnetic phase transition at 1.6 K. This was indicated by the lambda-type peak in its heat capacity and a negative paramagnetic Curie temperature. The electronic specific heat coefficient gamma of 52 mJ/mol K-2 suggested that CeHg3 is not a heavy fermion material contrary to its isostructural counterpart CeAl3. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 4 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 186 EP 188 DI 10.1016/S0921-4526(96)00585-6 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300055 ER PT J AU Kagayama, T Sawamura, T Oomi, G Lacerda, A Smith, JL AF Kagayama, T Sawamura, T Oomi, G Lacerda, A Smith, JL TI Effect of pressure on the electrical resistivity of CeBe13 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE CeBe13; high pressure; concentrated Kondo materials; resistivity ID STATE AB The electrical resistivity of the intermediate valence compound CeBe13 has been measured at high pressures to 2 GPa. The coefficient of T-2-term in the electrical resistivity rapidly decreases with increasing pressure, associated with an enhancement of the Kondo temperature T-K. Pressure dependence of the lattice constants was also measured to 12 GPa at room temperature. The volume dependence of the T-K and its Gruneisen parameter will be discussed briefly. C1 KUMAMOTO UNIV,FAC SCI,DEPT PHYS,KUMAMOTO 860,JAPAN. LOS ALAMOS NATL LAB,PULSE FACIL,NATL HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,STC,LOS ALAMOS,NM 87545. RP Kagayama, T (reprint author), KUMAMOTO UNIV,FAC ENGN,DEPT MECH ENGN & MAT SCI,KUROKAMI 2-39-1,KUMAMOTO 860,JAPAN. NR 11 TC 4 Z9 4 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 204 EP 207 DI 10.1016/S0921-4526(96)00591-1 PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300061 ER PT J AU Claessen, R Straub, T Steiner, P Hufner, S Eyert, V Anderson, RO Allen, JW Janowitz, C Olson, CG AF Claessen, R Straub, T Steiner, P Hufner, S Eyert, V Anderson, RO Allen, JW Janowitz, C Olson, CG TI Angle-resolved photoelectron spectroscopy on the Fermi liquid reference compound TiTe2 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE photoelectron spectroscopy; Fermi liquid; Fermi surface mapping; TiTe2 ID PHOTOEMISSION AB The layered compound TiTe2 can, for several reasons, be viewed as an ideal candidate for electron spectroscopic studies of Fermi liquid behavior. High-resolution angle-resolved photoemission (ARPES) spectra near the Fermi energy reflect the expected energy renormalization and lifetime narrowing of the quasiparticle excitations. These results support a many-body interpretation of ARPES on low-energy excitations in terms of the spectral function A(k,omega). We further present ARPES data measured in the constant energy mode and suggest a new method for obtaining precise information on the Fermi surface, which utilizes the discontinuity in the momentum distribution function of a Fermi liquid. C1 HAHN MEITNER INST BERLIN GMBH,D-14091 BERLIN,GERMANY. UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109. AMES LAB,AMES,IA 50011. IOWA STATE UNIV,AMES,IA 50011. RP Claessen, R (reprint author), UNIV SAARLAND,FACHBEREICH EXPT PHYS,D-66041 SAARBRUCKEN,GERMANY. RI Eyert, Volker/C-5968-2008; Claessen, Ralph/A-2045-2017 OI Claessen, Ralph/0000-0003-3682-6325 NR 10 TC 4 Z9 5 U1 3 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 294 EP 296 DI 10.1016/S0921-4526(96)00687-4 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300088 ER PT J AU Heffner, RH Le, LP Nieuwenhuys, GJ MacLaughlin, DE Amato, A Gygax, FN Schenck, A Kim, JS Stewart, G Ott, HR AF Heffner, RH Le, LP Nieuwenhuys, GJ MacLaughlin, DE Amato, A Gygax, FN Schenck, A Kim, JS Stewart, G Ott, HR TI Evidence for possible spin or orbital magnetism in the superconducting state of UBe12.91B0.09 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE heavy fermion superconductivity; mu SR spectroscopy; UBe12.91B0.09 ID HIGH-TEMPERATURE SUPERCONDUCTORS; UNCONVENTIONAL SUPERCONDUCTORS; PHASE-TRANSITION; U1-XTHXBE13; DIAGRAM; UBE13 AB Although the unconventional character of the superconductivity in pure and doped UBe13 has been well established, the precise nature of the superconducting order parameter is still unknown. We present muon spin rotation measurements in boron-doped UBe13 showing a paramagnetic frequency shift below the superconducting transition temperature which is nearly independent of applied magnetic field (0.01-0.10T), unlike a conventional Knight shift. No increase in line width is observed in zero field. These results are compared to observations of the paramagnetic Meissner effect in other superconductors, and are discussed in terms of the possible alignment of spin or orbital moments associated with unconventional superconductivity in this system. C1 LEIDEN UNIV,LEIDEN,NETHERLANDS. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. ETH ZURICH,ITP,CH-5232 VILLIGEN,SWITZERLAND. UNIV FLORIDA,GAINESVILLE,FL 32611. ETH HONGGERBERG,CH-8093 ZURICH,SWITZERLAND. RP Heffner, RH (reprint author), LOS ALAMOS NATL LAB,MS K764,LOS ALAMOS,NM 87545, USA. RI Amato, Alex/H-7674-2013 OI Amato, Alex/0000-0001-9963-7498 NR 22 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 398 EP 401 DI 10.1016/S0921-4526(96)00733-8 PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300119 ER PT J AU Fernando, GW Kocharian, AN Watson, RE Weinert, M AF Fernando, GW Kocharian, AN Watson, RE Weinert, M TI Stoner criterion of ferromagnetism and moment saturation in the Hubbard model with an applied magnetic field SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE stoner magnetism; ferromagnetic saturation; phase transitions ID ALPHA''-FE16N2 AB The intraatomic Coulomb repulsion of itinerant electrons provides another Stoner mechanism of band splitting leading to ferromagnetism. The behavior of the magnetization versus external magnetic field is derived by an approximate treatment of the local correlations in a simple mean-field approximation for 1D, 2D, and 3D cubic lattices. The criteria for first-order phase transition and full spin alignment in an applied magnetic field are found. These attempts should be regarded as a way to obtain an upper bound for the magnetic moments. The appearance of ferromagnetism is seen for larger values of the intraatomic interaction U and lattice parameter a. This study provides a better understanding of the mechanism of strong ferromagnetic saturation and may help explain the behavior of magnetic moments of certain Fe sites in Fe-N compounds. C1 UNION COLL,DEPT PHYS,SCHENECTADY,NY 12308. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Fernando, GW (reprint author), UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06269, USA. NR 7 TC 4 Z9 4 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 509 EP 512 DI 10.1016/S0921-4526(96)00629-1 PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300153 ER PT J AU MacLaughlin, DE Bernal, OO Amato, A Feyerherm, R Gygax, FN Schenck, A Heffner, RH Le, LP Nieuwenhuys, GJ Andraka, B vonLohneysen, H Stockert, O Ott, HR AF MacLaughlin, DE Bernal, OO Amato, A Feyerherm, R Gygax, FN Schenck, A Heffner, RH Le, LP Nieuwenhuys, GJ Andraka, B vonLohneysen, H Stockert, O Ott, HR TI mu SR studies of Kondo disorder in UCu5-xPdx and CeCu5.9Au0.1 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE UCu5-xPdx; CeCu5.9Au0.1; non-Fermi liquid system; mu SR spectroscopy ID FERMI-LIQUID BEHAVIOR; Y1-XUXPD3; ALLOY AB Muon spin rotation (mu SR) spectra in the non-Fermi-liquid (NFL) heavy-fermion alloys UCu5-xPdx (x = 1.0 and 1.5) and CeCu5.9Au0.1 yield estimates of the rms width (delta chi)(rms) of the inhomogeneous susceptibility distribution in these systems. In UCu5-xPdx, the temperature dependence of (delta chi)(rms) indicates a wide distribution of Kondo temperatures T-K, resulting in a significant number of uncompensated U spins with low T-K which cause NFL behavior. In contrast, mu SR lines in CeCu5.9Au0.1 are too narrow for such ''Kondo disorder'' to account for NFL properties unless, as seems unlikely, the correlation length for the susceptibility disorder is long in this alloy. C1 CALIF STATE UNIV LOS ANGELES,LOS ANGELES,CA 90032. ETH ZURICH,ITP,CH-5232 VILLIGEN,SWITZERLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LEIDEN UNIV,KAMERLINGH ONNES LAB,NL-2300 RA LEIDEN,NETHERLANDS. UNIV FLORIDA,GAINESVILLE,FL 32611. UNIV KARLSRUHE,INST PHYS,D-76128 KARLSRUHE,GERMANY. ETH HONGGERBERG,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND. RP MacLaughlin, DE (reprint author), UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521, USA. RI Feyerherm, Ralf/F-5487-2013; Amato, Alex/H-7674-2013 OI Feyerherm, Ralf/0000-0003-3034-4210; Amato, Alex/0000-0001-9963-7498 NR 15 TC 6 Z9 6 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 FEB PY 1997 VL 230 BP 606 EP 609 DI 10.1016/S0921-4526(96)00760-0 PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300176 ER PT J AU Nakotte, H Buschow, KHJ Bruck, E Klaasse, JCP Prokes, K deBoer, FR Andreev, AV Lacerda, A AF Nakotte, H Buschow, KHJ Bruck, E Klaasse, JCP Prokes, K deBoer, FR Andreev, AV Lacerda, A TI Non-Fermi-liquid scaling in U(Cu,Al)(5) compounds SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE non-Fermi liquid system; UCuxAl5-x ID BEHAVIOR AB We report on the electronic properties of various UCuxAl5-x. These compounds (2.9 less than or equal to x less than or equal to 3.5). These compounds crystallize in the hexagonal CaCu5 structure. For all compounds, we find that the low-temperature specific heat diverges logarithmitically, which may be taken as an indication of non-Fermi-liquid scaling in these materials. Also we find a large magnetic anisotropy in all compounds studied, and we show that the magnetic anisotropy should not be neglected in the analysis of other bulk properties. Though for some of UCuxAl5-x polycrystals non-Fermi-liquid scaling is found also in the magnetic susceptibility, comparison with single-crystal results on UCu3Al2 indicates that any temperature dependence may be due to averaging anisotropic response over all crystallographic directions. C1 UNIV AMSTERDAM,VAN DER WAALS ZEEMAN INST,NL-1018 XE AMSTERDAM,NETHERLANDS. ACAD SCI CZECH REPUBL,INST PHYS,CZ-18040 PRAGUE 8,CZECH REPUBLIC. LOS ALAMOS NATL LAB,NHMFL,PULSED FIELD FACIL,LOS ALAMOS,NM 87545. RP Nakotte, H (reprint author), LOS ALAMOS NATL LAB,MANUEL LUJAN JR NEUTRON SCATTERING CTR,LOS ALAMOS,NM 87545, USA. RI Andreev, Alexander/B-6057-2011; Bruck, Ekkes/E-3365-2014 NR 6 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 616 EP 619 DI 10.1016/S0921-4526(96)00763-6 PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300179 ER PT J AU Heffner, RH Le, LP MacLaughlin, DE Luke, GM Kojima, K Nachumi, B Uemura, YJ Nieuwenhuys, GJ Cheong, SW AF Heffner, RH Le, LP MacLaughlin, DE Luke, GM Kojima, K Nachumi, B Uemura, YJ Nieuwenhuys, GJ Cheong, SW TI Unusual relaxational dynamics in La1-xCaxMnO3 (x=0.33 and 0.67) SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE La1-xCaxMnO3; mu SR spectroscopy; magnetoresistive oxides; spin polarons ID LOW-TEMPERATURE; MAGNETORESISTANCE; FERROMAGNET AB Muon spin relaxation studies on La1-xCaxMnO3 (x = 0.33 and 0.67) powders show that the muon dynamic relaxation function changes from exponential above the magnetic transition temperature to stretched exponential below the critical temperature (T-C = 274 K for x = 0.33, T-N = 150 K for x = 0.67). This suggests a spatially inhomogeneous distribution of very slow Mn-ion correlation times. An anomalously small applied field destroys the dynamical signature of the ferromagnetic transition for x = 0.33, but not the antiferromagnetic transition for x = 0.67. The x = 0.67 system also shows the evidence of a change in the magnetic phase in zero field near T = 75 K. C1 UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. LEIDEN UNIV,KAMERLINGH ONNES LAB,NL-2300 RA LEIDEN,NETHERLANDS. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Heffner, RH (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MS K764,MST-10,LOS ALAMOS,NM 87545, USA. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 17 TC 9 Z9 9 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 FEB PY 1997 VL 230 BP 759 EP 761 DI 10.1016/S0921-4526(97)81596-7 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300221 ER PT J AU Oomi, G Kagayama, T Kawaguchi, K Canfield, PC Budko, SL AF Oomi, G Kagayama, T Kawaguchi, K Canfield, PC Budko, SL TI Effect of pressure and magnetic field on the electrical resistance of PrSb2 SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE PrSb2; magnetic transition; magnetoresistance; high pressure AB Electrical resistance of the nearly two-dimensional compound PrSb2 has been observed at high pressures up to 2.2 GPa and at magnetic fields up to 5 T. It is found that the antiferromagnetic ordering temperature T-N increases with pressure having a rate dT(N)/dP = 1.3 K GPa(-1). Metamagnetic phase transitions are found to be induced at magnetic fields of several T. C1 KUMAMOTO UNIV,FAC SCI,DEPT PHYS,KUMAMOTO 860,JAPAN. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Oomi, G (reprint author), KUMAMOTO UNIV,FAC ENGN,DEPT MECH ENGN & MAT SCI,KUROKAMI 2-39-1,KUMAMOTO 860,JAPAN. RI Canfield, Paul/H-2698-2014 NR 9 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 776 EP 779 DI 10.1016/S0921-4526(96)00837-X PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300226 ER PT J AU Buschinger, B Geibel, C Steglich, F Mandrus, D Young, D Sarrao, JL Fisk, Z AF Buschinger, B Geibel, C Steglich, F Mandrus, D Young, D Sarrao, JL Fisk, Z TI Transport properties of FeSi SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE FeSi; Kondo insulators; thermoelectric power; transport properties ID TEMPERATURE AB We have measured thermoelectric power, thermal conductivity and electric resistivity on FeSi samples, single crystal and polycrystals, with different qualities. Our data can be understood in terms of classic semiconductor physics. Good agreement is found with the results from recent band structure calculations. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. RP Buschinger, B (reprint author), TH DARMSTADT,INST FESTKORPERPHYS,HSCH STR 8,D-64289 DARMSTADT,GERMANY. RI Mandrus, David/H-3090-2014 NR 11 TC 21 Z9 21 U1 1 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 784 EP 786 DI 10.1016/S0921-4526(96)00839-3 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300228 ER PT J AU Chernikov, MA Felder, E Paschen, S Bianchi, AD Ott, HR Sarrao, JL Mandrus, D Fisk, Z AF Chernikov, MA Felder, E Paschen, S Bianchi, AD Ott, HR Sarrao, JL Mandrus, D Fisk, Z TI Low-temperature magnetic and thermodynamic properties of Fe1-xCoxSi SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE Fe1-xCoxSi; narrow-gap semiconductors; specific heat; magnetic susceptibility; thermodynamic properties AB We report measurements of the low-field AC magnetic susceptibility chi'(T,f) and of the specific heat C-p(T) for polycrystalline samples of Fe1-xCoxSi with 0 less than or equal to x less than or equal to 0.03 at low temperatures. For x greater than or equal to 0.01, the chi'(T) curves show maxima indicative of a spin-glass-type freezing of magnetic moments below 1 K. The small values of T-f/x and the T-f(f) variations both suggest a weak magnetic interaction. The specific heat C-p(T) contains a term gamma T which raises with increasing x from 2.1 T mJ mol(-1) K-1 for FeSi to 7.6 T mJ mol(-1) K-1 for Fe0.97Co0.03Si. C1 FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Chernikov, MA (reprint author), ETH HONGGERBERG,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND. RI Paschen, Silke/C-3841-2014; Mandrus, David/H-3090-2014; Bianchi, Andrea/E-9779-2010 OI Paschen, Silke/0000-0002-3796-0713; Bianchi, Andrea/0000-0001-9340-6971 NR 7 TC 3 Z9 3 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 790 EP 793 DI 10.1016/S0921-4526(96)00841-1 PG 4 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300230 ER PT J AU Kempa, K Broido, DA Weitering, HH AF Kempa, K Broido, DA Weitering, HH TI Correlational switching between 3x1 and 6x1 surface reconstructions on Si(111) with submonolayer Ag adsorption SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE silicon; surface reconstruction; correlational switching; ultrafast computing ID STRUCTURAL MODEL AB Electron correlations are strongly enhanced in low-dimensional systems. Taking correlations as the dominant mechanism, we provide an explanation of the recently observed electrostatically enforced structural phase transition(3 x 1 to 6 x 1) on a Si(1 1 1) surface with submonolayer Ag adsorption. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Kempa, K (reprint author), BOSTON COLL,DEPT PHYS,CHESTNUT HILL,MA 02167, USA. NR 7 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 800 EP 802 DI 10.1016/S0921-4526(96)00844-7 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300233 ER PT J AU Budko, SL Canfield, PC Yatskar, A Beyermann, WP AF Budko, SL Canfield, PC Yatskar, A Beyermann, WP TI (Lu1-xYbx)Ni2B2C: From 16 K superconductor to heavy fermion SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE heavy electron system; resistivity; specific heat; (Lu1-xYbx)Ni2B2C; phase diagram ID LUNI2B2C AB YbNi2B2C has recently been discovered to be a heavy fermion with a low-temperature Sommerfeld coefficient of 530 mJ/molK(2) and no magnetic order above 0.35 K. Based on thermodynamic and transport measurements on single-crystal samples the Kondo temperature is T-K approximate to 10 K. As a member of the RNi2B2C (R = Dy-Lu) series of magnetic superconductors R = Yb is remarkable since it does not superconduct for T > 0.35 K, even though the T-C's for TmNi2B2C and LuNi2B2C are 10.8 and 16.3 K, respectively. This is further evidence of the strong hybridization between the Yb 4f-levels and the conduction electrons. Electrical resistivity and specific heat data on single-crystal samples of (Yb1-xLux)Ni2B2C demonstrate how there is a systematic progression from a relatively high-temperature superconductor to a heavy fermion. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. RI Canfield, Paul/H-2698-2014 NR 8 TC 12 Z9 12 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 859 EP 861 DI 10.1016/S0921-4526(96)00736-3 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300250 ER PT J AU Yatskar, A Budko, SL Canfield, PC Beyermann, WP Schmiedeshoff, GM Torikachvili, MS Mielke, CH Lacerda, A AF Yatskar, A Budko, SL Canfield, PC Beyermann, WP Schmiedeshoff, GM Torikachvili, MS Mielke, CH Lacerda, A TI Magnetotransport measurements of single crystalline heavy fermion YbNi2B2C SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE magnetotransport; heavy electron system; YbNi2B2C ID SUPERCONDUCTIVITY; CECU6 AB We have measured transverse (B perpendicular to I) and longitudinal (B parallel to I) magnetoresistance on a single crystalline sample of YbNi2B2C. A remarkably large anisotropic transverse magnetoresistance was found when applying magnetic field parallel or perpendicular to the c-axis of the tetragonal crystallographic structure. A pronounced maximum at 10 T develops below 4 K in the transverse magnetoresistance when the magnetic field is applied along the c-axis, whereas a minimum is found at 7 T below 4 K when the applied field is perpendicular to the c-axis. Above 5 K both configurations (B parallel to c and B perpendicular to c) show a negative magnetoresistance. Finally, the possibility of a metamagnetic-like transition in this compound will be discussed in conjunction with high held magnetization experiments. C1 LOS ALAMOS NATL LAB,NALT HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. UNIV CALIF RIVERSIDE,DEPT PHYS,RIVERSIDE,CA 92521. AMES LAB,AMES,IA 50011. IOWA STATE UNIV,AMES,IA 50011. OCCIDENTAL COLL,DEPT PHYS,LOS ANGELES,CA 90041. SAN DIEGO STATE UNIV,DEPT PHYS,SAN DIEGO,CA 92182. RI Canfield, Paul/H-2698-2014 NR 11 TC 8 Z9 8 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 876 EP 878 DI 10.1016/S0921-4526(96)00741-7 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300255 ER PT J AU Bommeli, F Degiorgi, L Wachter, P Cho, BK Canfield, PC Chau, R Maple, MB AF Bommeli, F Degiorgi, L Wachter, P Cho, BK Canfield, PC Chau, R Maple, MB TI Optical properties of the borocarbide superconductors SO PHYSICA B LA English DT Article; Proceedings Paper CT SCES 96 CY AUG 19-22, 1996 CL ZURICH, SWITZERLAND DE superconductivity; optical properties; LuNi2B2C; YNi2B2C ID MAGNETISM AB We have measured the optical reflectivity of LuNi2B2C and YNi2B2C compounds, and have evaluated the optical conductivity both above and below the superconducting transition temperature. The normal state optical properties suggest that these superconductors are almost in the clean limit. Our results below T-c give, however, evidence of a superconducting gap signature, and are in agreement with a moderate-to-strong coupling limit of the BCS theory. C1 AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,INST PURE & APPL PHYS SCI,LA JOLLA,CA 92093. RP Bommeli, F (reprint author), ETH ZURICH,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND. RI Canfield, Paul/H-2698-2014 NR 10 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4526 J9 PHYSICA B JI Physica B PD FEB PY 1997 VL 230 BP 879 EP 881 DI 10.1016/S0921-4526(97)81597-9 PG 3 WC Physics, Condensed Matter SC Physics GA WW403 UT WOS:A1997WW40300256 ER PT J AU Vaknin, D Miller, LL Zarestky, JL Johnston, DC AF Vaknin, D Miller, LL Zarestky, JL Johnston, DC TI Elastic and quasielastic neutron scattering study of the spin-1/2 square lattice antiferromagnet Sr2CuO2Cl2 SO PHYSICA C LA English DT Article ID HEISENBERG-ANTIFERROMAGNET; LOW-TEMPERATURES; SINGLE-CRYSTAL; APICAL OXYGENS; MONTE-CARLO; LA2CUO4; TRANSITION; MODEL; PURE; SUPERCONDUCTIVITY AB Neutron scattering and magnetic susceptibility chi versus temperature T measurements are reported for a single crystal of the spin-1/2 square lattice Heisenberg antiferromagnet Sr2CuO2Cl2. Neutron Bragg diffraction measurements of the antiferromagnetic (1/2 1/2 0) peak showed that the Neel temperature is T-N = (256 +/- 6)K, whereas the chi(T) for magnetic field applied parallel to the c-axis, chi(c)(T), showed a broad minimum at T-c0 similar to 330 K, with no obvious feature at T-N. The two-dimensional (2D) quasielastic neutron scattering intensity, integrated across the (1/2 1/2 l) 2D magnetic scattering rod, I(T), was found to increase approximately linearly with T from 10 to similar to 240 K, consistent with expectation from spin-wave theory. A broad maximum in I(T) was found above T-N at T-c0 approximate to 300 K. Following B.J. Suh et al. [Phys. Rev. Lett. 75 (1995) 2212], we infer that this maximum and the corresponding broad minimum in chi(c)(T) at T-c0 > T-N reflect a crossover from Heisenberg to XY-like behavior upon cooling below T-c0 similar to 300 K. A simple model for I(T) supports this interpretation. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Vaknin, D (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Vaknin, David/B-3302-2009 OI Vaknin, David/0000-0002-0899-9248 NR 49 TC 8 Z9 8 U1 1 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 FEB 1 PY 1997 VL 274 IS 3-4 BP 331 EP 341 DI 10.1016/S0921-4534(96)00691-0 PG 11 WC Physics, Applied SC Physics GA WJ461 UT WOS:A1997WJ46100018 ER PT J AU Christiansen, PL GronbechJensen, N Lomdahl, PS Malomed, BA AF Christiansen, PL GronbechJensen, N Lomdahl, PS Malomed, BA TI Oscillations of eccentric pulsons SO PHYSICA SCRIPTA LA English DT Article ID SINE-GORDON EQUATION; SOLITONS; DYNAMICS; KINKS; MODEL AB Perturbation theory for elliptic pulsons is developed and predicts pulson and eccentricity oscillations. The pulson oscillation period is predicted qualitatively correct. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. TEL AVIV UNIV,SCH MATH SCI,IL-69978 RAMAT AVIV,ISRAEL. RP Christiansen, PL (reprint author), TECH UNIV DENMARK,INST MATH MODELLING,BLD 321,DK-2800 LYNGBY,DENMARK. RI Christiansen, Peter /A-7978-2011 OI Christiansen, Peter /0000-0002-1465-9987 NR 17 TC 21 Z9 21 U1 0 U2 0 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 FEB PY 1997 VL 55 IS 2 BP 131 EP 134 DI 10.1088/0031-8949/55/2/002 PG 4 WC Physics, Multidisciplinary SC Physics GA WL408 UT WOS:A1997WL40800002 ER PT J AU Knill, E Laflamme, R AF Knill, E Laflamme, R TI Theory of quantum error-correcting codes SO PHYSICAL REVIEW A LA English DT Article ID LOGIC GATE; COMPUTERS AB Quantum error correction will be necessary for preserving coherent states against noise and other unwanted interactions in quantum computation and communication. We develop a general theory of quantum error correction based on encoding states into larger Hilbert spaces subject to known interactions. We obtain necessary and sufficient conditions for the perfect recovery of an encoded state after its degradation by an interaction. The conditions depend only on the behavior of the logical states. We use them to give a recovery-operator-independent definition of error-correcting codes. We relate this definition to four others: the existence of a left inverse of the interaction, an explicit representation of the error syndrome using tensor products, perfect recovery of the completely entangled state, and an information theoretic identity. Two notions of fidelity and error for imperfect recovery are introduced, one for pure and the other for entangled states. The latter is more appropriate when using codes in a quantum memory or in applications of quantum teleportation to communication. We show that the error for entangled states is bounded linearly by the error for pure states. A formal definition of independent interactions for qubits is given. This leads to lower bounds on the number of qubits required to correct e errors and a formal proof that the classical bounds on the probability of error of e-error-correcting codes applies to e-error-correcting quantum codes, provided that the interaction is dominated by an identity component. RP Knill, E (reprint author), LOS ALAMOS NATL LAB,CIC-3,MAIL STOP B265,LOS ALAMOS,NM 87545, USA. NR 27 TC 679 Z9 694 U1 4 U2 34 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 FEB PY 1997 VL 55 IS 2 BP 900 EP 911 DI 10.1103/PhysRevA.55.900 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900012 ER PT J AU Ali, R Ahmad, I Dunford, RW Gemmell, DS Jung, M Kanter, EP Mokler, PH Berry, HG Livingston, AE Cheng, S Curtis, LJ AF Ali, R Ahmad, I Dunford, RW Gemmell, DS Jung, M Kanter, EP Mokler, PH Berry, HG Livingston, AE Cheng, S Curtis, LJ TI Shape of the two-photon-continuum emission from the 1s2s(1)S(0) state in He-like krypton SO PHYSICAL REVIEW A LA English DT Article ID 2-PHOTON DECAY-RATES; INNER-SHELL TRANSITIONS; ONE-ELECTRON ATOMS; FORBIDDEN TRANSITIONS; HYDROGENLIKE ATOMS; SI(LI) DETECTORS; S-1(0) STATE; 22S1/2 STATE; XENON ATOMS; M1 DECAY AB We report a measurement of the spectral distribution of photons from the two-photon decay of the 1s2s S-1(0) level in heliumlike krypton. In the experiment, a beam of Kr34+ ions was excited using a thin carbon foil and the two-photon decays were observed as coincidences in an array of x-ray detectors. An important part of this work was the measurement of the efficiency of the detection system as a function of photon energy. A Monte Carlo model of the experiment was used to compare the data with theoretical calculations and demonstrated good agreement with the nonrelativistic calculations for 2=36. C1 UNIV NOTRE DAME,DEPT PHYS,NOTRE DAME,IN 46556. UNIV TOLEDO,DEPT PHYS & ASTRON,TOLEDO,OH 43606. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RI Ali, Rami/B-8198-2015 OI Ali, Rami/0000-0002-5273-882X NR 84 TC 30 Z9 30 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB PY 1997 VL 55 IS 2 BP 994 EP 1006 DI 10.1103/PhysRevA.55.994 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900024 ER PT J AU Morgan, DV Sagurton, M Bartlett, RJ AF Morgan, DV Sagurton, M Bartlett, RJ TI Single-photon multiple ionization of neon in the K-edge region SO PHYSICAL REVIEW A LA English DT Article ID SHELL IONIZATION; HOLLOW IONS; AUGER; PHOTOIONIZATION; DECAY; XE; LINES; ATOMS; AR AB The ion charge state yields resulting from the photoionization of neon gas have been measured with time-of-flight ion charge state spectroscopy for excitation energies in the K-edge region. The decay of the [1s]3p resonance excited state results in the formation ion charge states Ne+, Ne2+, Ne3+, and Ne4+, with a branching ratio of 0.65:0.32:0.030:0.002, whereas the final charge state for the decay of higher-order [1s]np(n greater than or equal to 4) and [1s]epsilon p continuum excitations is mostly Ne2+. We have measured (q) over bar, the mean charge from photoionization, for excited states near the K edge as a function of photon energy. Postcollision interaction effects are shown to be quite small. C1 BROOKHAVEN NATL LAB,NSLS,LOS ALAMOS LAB SFA,UPTON,NY 11973. RP Morgan, DV (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 21 TC 18 Z9 18 U1 0 U2 5 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 FEB PY 1997 VL 55 IS 2 BP 1113 EP 1118 DI 10.1103/PhysRevA.55.1113 PG 6 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900037 ER PT J AU Chou, TT Yang, CN Yu, LH AF Chou, TT Yang, CN Yu, LH TI Momentum distribution for bosons with positive scattering length in a trap SO PHYSICAL REVIEW A LA English DT Article AB The coordinate-momentum double distribution function rho((r) over right arrow,(p) over right arrow)d(3)rd(3)p is calculated in the local density approximation for bosons with positive scattering length a in a trap. The calculation is valid to the first order of a. To clarify the meaning of the result, it is compared for a special case with the double distribution function rho(w)d(3)rd(3)p of Wigner. C1 SUNY STONY BROOK,INST THEORET PHYS,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP Chou, TT (reprint author), UNIV GEORGIA,DEPT PHYS,ATHENS,GA 30602, USA. NR 9 TC 26 Z9 30 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 FEB PY 1997 VL 55 IS 2 BP 1179 EP 1181 DI 10.1103/PhysRevA.55.1179 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900044 ER PT J AU Wu, W Datz, S Jones, NL Krause, HF Rosner, B Sorge, KD Vane, CR AF Wu, W Datz, S Jones, NL Krause, HF Rosner, B Sorge, KD Vane, CR TI Quasifree electron process in the single ionization of He by fast protons SO PHYSICAL REVIEW A LA English DT Article ID CROSS-SECTIONS; COLLISIONS; DISTRIBUTIONS; TARGETS AB Double-differential cross sections for the single ionization of He by protons are measured at collision energies of 2, 2.8, and 6 MeV. At energy losses larger than 0.75 keV, single ionization is shown to be dominated by binary encounters between the proton and a quasifree target electron. The measured scattering angle and energy loss of the protons show a simple two-body kinematic relation. Furthermore, the measured shapes of differential cross sections are in good agreement with calculations of Rutherford scattering from electrons. C1 TECHNION ISRAEL INST TECHNOL,IL-32000 HAIFA,ISRAEL. HASTINGS COLL LAW,HASTINGS,NE 68901. RP Wu, W (reprint author), OAK RIDGE NATL LAB,DIV PHYS,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 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 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB PY 1997 VL 55 IS 2 BP 1537 EP 1539 DI 10.1103/PhysRevA.55.1537 PG 3 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900087 ER PT J AU Claytor, N Belkacem, A Dinneen, T Feinberg, B Gould, H AF Claytor, N Belkacem, A Dinneen, T Feinberg, B Gould, H TI Ionization of Au78+ and electron capture by Au79+ at 10.8 GeV/nucleon SO PHYSICAL REVIEW A LA English DT Article ID RELATIVISTIC HEAVY-IONS; POSITRON PAIR PRODUCTION; ATOMIC-COLLISIONS; CROSS-SECTIONS; CHARGE STATES AB We have measured the cross sections for ionizating one-electron Au78+ and the total cross sections for electron capture by bare Au79+ at 10.8 GeV/nucleon in C, Al, Cu, Ag, and Au targets. We made the measurement by magnetically separating the charge states and measuring the fraction of Au78+ as a function of target thickness for each element. In contrast to the results reported by Westphal and He [Phys. Rev. Lett. 71, 1160 (1993)], our ionization measurements agree with the calculation of Anholt and Becker [Phys. Rev. A 36, 4628 (1987)]. Our capture cross-section measurements are in agreement with theory for those targets where radiative electron capture is the dominant capture process. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 22 TC 46 Z9 46 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 FEB PY 1997 VL 55 IS 2 BP R842 EP R845 DI 10.1103/PhysRevA.55.R842 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900002 ER PT J AU Frey, MT Dunning, FB Reinhold, CO Burgdorfer, J AF Frey, MT Dunning, FB Reinhold, CO Burgdorfer, J TI Very-high-n Stark wave packets generated by an electric-field step SO PHYSICAL REVIEW A LA English DT Article ID HALF-CYCLE PULSES; RYDBERG ATOMS; IONIZATION; DYNAMICS AB Wave packets comprising a coherent superposition of n similar or equal to 390 Stark states have been created in potassium by rapid application of a de field. Their properties are examined using a half-cycle probe pulse that is applied following a variable time delay and that ionizes a fraction of the excited atoms. The survival probability exhibits pronounced oscillations (quantum beats) that are associated with the time evolution of the wave packet. Interestingly, even in the present regime of complete overlap of different Stark manifolds, a single dominant beat frequency is observed, and this is explained quantum mechanically in terms of energy-level statistics. Similar behavior is predicted by classical trajectory Monte Carlo simulations that reproduce well the experimental observations demonstrating classical-quantum correspondence in high-n systems. C1 RICE UNIV,RICE QUANTUM INST,HOUSTON,TX 77005. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RP Frey, MT (reprint author), RICE UNIV,DEPT PHYS,6100 S MAIN ST,HOUSTON,TX 77005, USA. OI Reinhold, Carlos/0000-0003-0100-4962 NR 15 TC 19 Z9 19 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1050-2947 J9 PHYS REV A JI Phys. Rev. A PD FEB PY 1997 VL 55 IS 2 BP R865 EP R868 DI 10.1103/PhysRevA.55.R865 PG 4 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WH919 UT WOS:A1997WH91900008 ER PT J AU Schabel, MC Park, CH Matsuura, A Shen, ZX Bonn, DA Liang, RX Hardy, WN AF Schabel, MC Park, CH Matsuura, A Shen, ZX Bonn, DA Liang, RX Hardy, WN TI Superconducting-gap anisotropy in YBa2CU3O7-delta: Photoemission results on untwinned crystals SO PHYSICAL REVIEW B LA English DT Article ID BI2SR2CACU2O8+DELTA AB Polarization-dependent angle-resolved photoemission studies of untwinned single crystals of YBa2Cu3O6.95 (Y123) reveal modifications of the near-Fermi-edge spectral weight which are indicative of an anisotropic superconducting gap. The measured magnitude of the leading edge shift increases monotonically from the T-S line toward the zone boundary, reaching a maximum value of approximately 25 meV, similar to the behavior seen in Bi2Sr2CaCu2O8+delta (Bi2212). Within experimental uncertainty, we find variation;which is consistent with that expected for a d(x2-y2) order parameter, providing additional evidence in support of the d-wave pairing hypothesis. C1 STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. UNIV BRITISH COLUMBIA,DEPT PHYS & ASTRON,VANCOUVER,BC V6T 1Z1,CANADA. RP Schabel, MC (reprint author), STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94305, USA. NR 14 TC 46 Z9 47 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 2796 EP 2799 DI 10.1103/PhysRevB.55.2796 PG 4 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600029 ER PT J AU Boettger, JC Wallace, DC AF Boettger, JC Wallace, DC TI Metastability and dynamics of the shock-induced phase transition in iron SO PHYSICAL REVIEW B LA English DT Article ID THERMODYNAMIC PROPERTIES; METALS; WAVE; COMPRESSION; ELEMENTS; SODIUM; CORE AB The shock-induced alpha(bcc)-->epsilon(hcp) transition in iron begins at 13 GPa on the Hugoniot. In the two-phase region above 13 GPa, the Hugoniot lies well above the equilibrium surface defined by G(alpha)=G(epsilon), with G the Gibbs free energy. Also, the phase transition relaxation time tau is uncertain, with estimates ranging from <50 ns to approximate to 180 ns. Here we present an extensive study of these important aspects, metastability and dynamics, of the alpha-epsilon transition in iron. Our primary theoretical tools are (a) accurate theoretically based free energies for alpha and epsilon phases of iron and (b) accurate calculations of the wave evolution following planar impacts. We define metastable surfaces for forward and reverse transitions by the condition that the thermodynamic driving force G(alpha)-G(epsilon) is just balanced by an opposing force resulting from elastic stresses, and we calibrate the forward surface from the Hugoniot and the reverse surface from the phase interface reflection feature of shock profiles. These metastable surfaces, corresponding to alpha< - >epsilon transitions proceeding at a rate of tens of nanoseconds, are in remarkable agreement with quasistatic diamond cell measurements. When the relaxation time tau is calibrated from the rise time of the P2 wave, our calculated wave profiles are in good agreement with VISAR data. The overall comparison of theory and experiment indicates that (a) tau depends on shock strength and is approximately 60-->12 us for shocks of 17-->30 GPa, and (b) while tau expresses linear irreversible-thermodynamic relaxation, some nonlinear relaxation must also be present in the shock process in iron. RP LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 39 TC 98 Z9 103 U1 2 U2 9 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 FEB 1 PY 1997 VL 55 IS 5 BP 2840 EP 2849 DI 10.1103/PhysRevB.55.2840 PG 10 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600035 ER PT J AU Nagel, LJ Fultz, B Robertson, JL Spooner, S AF Nagel, LJ Fultz, B Robertson, JL Spooner, S TI Vibrational entropy and microstructural effects on the thermodynamics of partially disordered and ordered Ni3V SO PHYSICAL REVIEW B LA English DT Article ID 1ST-PRINCIPLES CALCULATION; NEUTRON-SCATTERING; ALLOYS; STATES; DENSITIES; SILICON; CU AB Samples of Ni3V were prepared with two microstructures: (1) with equilibrium D0(22) order, and (2) with partial disorder (having a large D0(22) chemical order parameter, but without the tetragonality of the unit cell). For both materials, we measured the difference in their heat capacities from 60 to 325 K, inelastic neutron-scattering spectra at four values of Q at 11 and at 300 K, and Young's moduli and coefficients of thermal expansion. The difference in heat capacity at low temperatures was consistent with a harmonic model using the phonon density of states (DOS) curves determined from the inelastic neutron-scattering spectra. In contrast, at temperatures greater than 160 K the difference in heat capacity did not approach zero, as expected of harmonic behavior. The temperature dependence of the phonon DOS can be used to approximately account for the anharmonic contributions to the differential heat capacity. We also argue that some of the anharmonic behavior should originate with a microstructural contribution to the heat capacity involving anisotropic thermal contractions of the D0(22) structure. We estimate the difference in vibrational entropy between partially disordered and ordered Ni3V to be S-pdis-S-ord=(+0.038+/-0.015)k(B)/atom at 300 K. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Nagel, LJ (reprint author), CALTECH,MS 138-78,PASADENA,CA 91125, USA. NR 35 TC 19 Z9 19 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 2903 EP 2911 DI 10.1103/PhysRevB.55.2903 PG 9 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600045 ER PT J AU Radaelli, PG Cox, DE Marezio, M Cheong, SW AF Radaelli, PG Cox, DE Marezio, M Cheong, SW TI Charge, orbital, and magnetic ordering in La0.5Ca0.5MnO3 SO PHYSICAL REVIEW B LA English DT Article ID POWDER DIFFRACTION; MAGNETORESISTANCE; LA1-XCAXMNO3; FILMS AB The unusual magnetic properties of La0.5Ca0.5MnO3 were found to be associated with structural and magnetic ordering phenomena, resulting from the close interplay between charge, orbital, and magnetic ordering. Analysis of synchrotron x-ray and neutron powder diffraction data indicates that the anomalous and hysteretic behavior of the lattice parameters occurring between T-C similar to 225 K and T-N similar to 155 K is due to the development of a Jahn-Teller (J-T) distortion of the MnO6 octahedra, the d(z)(2) orbitals being oriented perpendicular to the orthorhombic b axis. We observed an unusual broadening of the x-ray Bragg reflections throughout this temperature region, suggesting that this process occurs in stages. Below TN, the development of well-defined satellite peaks in the x-ray patterns, associated with a transverse modulation with q = [1/2- epsilon,0,0], indicates that quasicommensurate (epsilon similar to 0) orbital ordering occurs within the a-e plane as well. The basic structural features of the charge-ordered low-temperature phase were determined from these satellite peaks. The low-temperature magnetic structure is characterized by systematic broadening of the magnetic peaks associated with the ''Mn+3'' magnetic sublattice. This phenomenon can be explained by the presence of magnetic domain boundaries, which break the coherence of the spin ordering on the Mn+3 sites while preserving the coherence of the spin ordering on the Mn+4 sublattice as well as the identity of the two sublattices. The striking resemblance between these structures and the structural ''charge ordering'' and ''discommensuration'' domain boundaries, which were recently observed by electron diffraction and real-space imaging, strongly suggests that these two types of structures are the same and implies that, in this system, commensurate long-range charge ordering coexists with quasicommensurate orbital ordering. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. CNR,MASPEC,I-43100 PARMA,ITALY. AT&T BELL LABS,MURRAY HILL,NJ 07974. RP Radaelli, PG (reprint author), INST MAX VON LAUE PAUL LANGEVIN,BOITE POSTALE 156,F-38042 GRENOBLE 09,FRANCE. RI Radaelli, Paolo/C-2952-2011 OI Radaelli, Paolo/0000-0002-6717-035X NR 19 TC 756 Z9 760 U1 13 U2 88 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 3015 EP 3023 DI 10.1103/PhysRevB.55.3015 PG 9 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600060 ER PT J AU Rettori, C Rao, D Singley, J Kidwell, D Oseroff, SB Causa, MT Neumeier, JJ McClellan, KJ Cheong, SW Schultz, S AF Rettori, C Rao, D Singley, J Kidwell, D Oseroff, SB Causa, MT Neumeier, JJ McClellan, KJ Cheong, SW Schultz, S TI Temperature dependence of the ESR linewidth in the paramagnetic phase (T>T-C) of R(1-x)B(x)MnO(3+delta) (R=La,Pr; B=Ca,Sr) SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-SPIN-RESONANCE; MAGNETIC-FIELD; MAGNETORESISTANCE; LA1-XSRXMNO3; EXCHANGE; FILMS; (LA0.8CA0.2)MNO3; RESISTIVITY; TRANSITION AB Electron spin resonance (ESR) experiments in the paramagnetic phase of R(1-x)B(x)MnO(3+delta) (R=La,Pr; B=Ca,Sr) show, for 1.1 T-C less than or similar to T less than or similar to 2T(C), a linear T increase of the resonance linewidth, Delta H, in powders, ceramic pellets, and single crystals. Above similar to 2T(C) a slowdown in the T increase of Delta H is observed. The data resemble the results found in other ferromagnetic insulators where the spin-lattice relaxation involves a single-phonon process. We find that the one-phonon process may account for the linear T dependence of the linewidth observed up to similar to 2T(C). A large T dependence of the resonance intensity above T-C was found in all the samples studied, suggesting the existence of spin clusters in these compounds over a wide range of temperature. C1 CTR ATOM BARILOCHE,RA-8400 SAN CARLOS BARILO,RIO NEGRO,ARGENTINA. INST BALSEIRO,RA-8400 SAN CARLOS BARILO,RIO NEGRO,ARGENTINA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. AT&T BELL LABS,MURRAY HILL,NJ 07974. UNIV CALIF SAN DIEGO,LA JOLLA,CA 92037. RP Rettori, C (reprint author), SAN DIEGO STATE UNIV,SAN DIEGO,CA 92182, USA. RI Rettori, Carlos/C-3966-2012 OI Rettori, Carlos/0000-0001-6692-7915 NR 43 TC 105 Z9 106 U1 0 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 3083 EP 3086 DI 10.1103/PhysRevB.55.3083 PG 4 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600070 ER PT J AU Chen, JM Liu, RG Chung, SC Liu, RS Kramer, MJ Dennis, KW McCallum, RW AF Chen, JM Liu, RG Chung, SC Liu, RS Kramer, MJ Dennis, KW McCallum, RW TI Soft-x-ray absorption spectroscopy of Nd1+xBa2-xCu3O7+delta (x=0-0.6) SO PHYSICAL REVIEW B LA English DT Article ID CHARGE-TRANSFER; ELECTRONIC-STRUCTURE; HOLE CONCENTRATION; OXYGEN; SYMMETRY; SUPERCONDUCTIVITY; YBA2CU3O7-DELTA; STATES; TC; TEMPERATURE AB O K-edge and Cu L(23)-edge x-ray-absorption near-edge-structure spectra for the series of Nd1+xBa2-xCu3O7+delta compounds (x=0-0.6) were measured using a bulk-sensitive x-ray fluorescence yield technique. Near the O 1s edge, pre-edge peaks at similar to 527.5 and similar to 528.2 eV are ascribed to the excitations of O 1s electrons to O 2p holes located in the CuO3 ribbons and CuO2 planes, respectively. The peak at similar to 528.2 eV decreases in intensity with increasing the Nd doping, indicating the filling of holes in the CuO2 planes by the substitution of Nd3+ for Ba2+ in the Nd1+xBa2-xCu3O7+delta system. For low levels of Nd doping, the holes are located mainly in the CuO2 planes. At higher Nd doping, the holes are located predominantly in the CuO3 ribbons. The depression in T-c for the Nd1+xBa2-xCu3O7+delta system correlates closely with the hole concentration in the CuO2 planes and the number of disrupted fourfold-coordinated Cu on the chain sites. The high-energy shoulders in the Cu L(23)-edge absorption spectra arise from Cu3d(9)L defected states to Cu2p(-1)3d(10)L excited states, where L denotes the ligand hole on the CuO3 ribbons and CuO2 planes. With increasing the Nd doping, the shoulders shift to higher energy similar to 0.3 eV from x=0 to 0.6. C1 NATL TAIWAN UNIV,DEPT CHEM,TAIPEI 10764,TAIWAN. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Chen, JM (reprint author), SRRC,HSINCHU,TAIWAN. RI Liu, Ru-Shi/A-6796-2010 OI Liu, Ru-Shi/0000-0002-1291-9052 NR 30 TC 18 Z9 18 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 3186 EP 3191 DI 10.1103/PhysRevB.55.3186 PG 6 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600083 ER PT J AU Klemm, RA AF Klemm, RA TI Some improved geometries for Josephson-junction investigations of the order-parameter symmetry in high-T-c superconductors SO PHYSICAL REVIEW B LA English DT Article ID PB DC SQUIDS; PAIRING STATE; TUNNEL-JUNCTIONS; GRAIN-BOUNDARIES; PHASE COHERENCE; YBA2CU3O7-DELTA; VORTEX; FILMS; YBCO AB We propose two new geometries for Josephson junction experiments between the edge of an orthorhombic, untwinned single-crystal high-T-c superconductor, assumed to have an order parameter of the mixed s +/- d(x2-y2) variety, and a conventional, s-wave superconductor. The first geometry is a straight-edge Josephson junction cut at an angle phi(0) with respect to the a-axis edge of a high-T-c crystal. We studied the effects of a regular array of a/b steps comprising the edge upon the I-c(B) pattern for different phi(0) values. Varying phi(0) can elucidate the locations of any purported order-parameter nodes. The second geometry is a disk cut from a high-T-c single crystal, with a Josephson junction formed on the edge, centered at phi(0), with an angular width of Delta phi. The case Delta phi = pi is nearly free of systematic flux trapping problems, and is shown to be particularly important in quantifying the precise amount of s/d order-parameter mixing. Smaller Delta phi values can also be useful in locating the purported order-parameter nodes. RP Klemm, RA (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 45 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 3249 EP 3257 DI 10.1103/PhysRevB.55.3249 PG 9 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600090 ER PT J AU Wijngaarden, RJ Griessen, R Fendrich, J Kwok, WK AF Wijngaarden, RJ Griessen, R Fendrich, J Kwok, WK TI Influence of twin planes in YBa2Cu3O7 on magnetic flux movement and current flow SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTALS; BOUNDARIES; PENETRATION; SUPERCONDUCTORS AB The effect of twin planes in YBa2Cu3O7 on the superconducting current flow is investigated. A single crystal containing only two twin planes is studied magneto-optically up to 1 T. It is found that flux enters the crystal very easily along the twin planes, but that it does not leave the sample preferentially along the twin planes. The flux present in the twin planes reduces the flux penetration in adjacent regions of the sample. During flux penetration, the current density across the twin plane is about half of the current density in the rest of the sample. Due to this, the shielding current breaks up into several subloops. From a simulation follows that in a thin sample flux penetration is enhanced at inward pointing irregularities of the edge of the sample. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Wijngaarden, RJ (reprint author), FREE UNIV AMSTERDAM,DEPT PHYS & ASTRON,DE BOELELAAN 1081,NL-1081 HV AMSTERDAM,NETHERLANDS. NR 22 TC 37 Z9 37 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 3268 EP 3275 DI 10.1103/PhysRevB.55.3268 PG 8 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600092 ER PT J AU Goodwin, TJ Shelton, RN Radousky, HB Rosov, N Lynn, JW AF Goodwin, TJ Shelton, RN Radousky, HB Rosov, N Lynn, JW TI Pr and Cu magnetism in (Pr1.5Ce0.5)Sr(2)Cu(2)MO(10-delta) (M=Nb, Ta): Correlations with a suppression of superconductivity SO PHYSICAL REVIEW B LA English DT Article ID TEMPERATURE SPECIFIC-HEAT; RARE-EARTH; CUPRATE; Y1-XPRXBA2CU3O7; METAMAGNETISM; LA2CUO4; PLANES; OXIDES; R2CUO4; SYSTEM AB The magnetic properties of nonsuperconducting (Pr1.5Ce0.5)Sr(2)Cu(2)MO(10-delta) with M = Nb, Ta are characterized with de magnetization, specific-heat, and neutron-diffraction experiments. Data for (Pr1.5Ce0.5)Sr2Cu2NbO10-delta reveal complex Cu magnetism marked by antiferromagnetic order below 200 K, spin structure transitions at 130 and 57 K, both collinear and noncollinear antiferromagnetic spin structures, and weak ferromagnetic behavior below 130 K. The data also indicate an anomalous ordering of the Pr spins near 10 K, a large linear contribution to the low-temperature specific heat, and a Pr 4f crystal-field ground state similar to that found in PrBa2Cu3O7. Furthermore, there is evidence that the weak ferromagnetic behavior couples to the Pr ordering near 10 K. Identical Pr magnetism and similar Cu magnetism are found in (Pr1.5Ce0.5)Sr2Cu2TaO10-delta, deoxygenated (Pr1.5Ce0.5)Sr2Cu2NbO10-delta, and deoxygenated (Pr1.5Ce0.5)Sr2Cu2TaO10-delta. These results indicate that superconductivity is suppressed in these compounds in the same phenomenological manner as in PrBa2Cu3O7. We interpret this as evidence that superconductivity is suppressed by the same mechanism in both structures and propose that a general correlation exists between anomalous Pr magnetism and a lack of superconductivity in these Pr-based high-T-c cuprates. The significance of these results and analyses to understanding and modeling the suppression of superconductivity by Pr in high-T-c cuprates is discussed. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NIST,DIV REACTOR RADIAT,GAITHERSBURG,MD 20899. RP Goodwin, TJ (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 43 TC 14 Z9 14 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 5 BP 3297 EP 3307 DI 10.1103/PhysRevB.55.3297 PG 11 WC Physics, Condensed Matter SC Physics GA WG886 UT WOS:A1997WG88600095 ER PT J AU Gumbsch, P Zhou, SJ Holian, BL AF Gumbsch, P Zhou, SJ Holian, BL TI Molecular dynamics investigation of dynamic crack stability SO PHYSICAL REVIEW B LA English DT Article ID DISLOCATION NUCLEATION; BRITTLE-FRACTURE; INSTABILITY; MODEL; PROPAGATION; SIMULATIONS; EMISSION; LATTICE AB A series of molecular-dynamics simulations has been performed in order to evaluate the effects of several physical factors on dynamic crack stability. These factors are the crystalline structure and the interatomic interaction modeled by various empirical potentials. For brittle crack propagation at low temperature we find that steady-state crack velocities are limited to a band of accessible values. Increasing the overload beyond K-lc, the crack can propagate with a steady-state velocity, which quickly reaches the terminal velocity of about 0.4 of the Rayleigh wave speed. The magnitude of the terminal velocity can be related to the nonlinearity of the interatomic interaction. Further increasing the overload does not change the steady-state velocity dramatically, but significantly increases the amplitude of acoustic emission from the crack tip. Loading the crack even further leads to instabilities which take the form of cleavage steps, dislocation emission, or branching. The instability is closely related to the buildup of a localized coherent, phononlike field generated by the bond-breaking events. The form of the instability depends critically on crystal structure and on the crystallographic orientation of the crack system but can also be correlated with the relative ease of dislocation generation (and motion). C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. MAX PLANCK INST MET RES,INST WERKSTOFFWISSENSCH,D-70174 STUTTGART,GERMANY. RI Gumbsch, Peter/E-5879-2012 OI Gumbsch, Peter/0000-0001-7995-228X NR 29 TC 97 Z9 97 U1 1 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 6 BP 3445 EP 3455 DI 10.1103/PhysRevB.55.3445 PG 11 WC Physics, Condensed Matter SC Physics GA WJ875 UT WOS:A1997WJ87500028 ER PT J AU Garrett, AW Nagler, SE Barnes, T Sales, BC AF Garrett, AW Nagler, SE Barnes, T Sales, BC TI Neutron-scattering study of magnetic excitations in (VO)(2)P2O7 SO PHYSICAL REVIEW B LA English DT Article ID LADDER; SUSCEPTIBILITY; (VO)2P2O7 AB We report results from inelastic neutron-scattering experiments on powder samples of vanadyl pyrophosphate, (VO)(2)P2O7 (VOPO). We see evidence for three magnetic excitations, at 3.5, 6.0, and 14 meV. The 3.5 meV mode peaks at Q=0.8 Angstrom(-1) and is consistent with the one-magnon gap mode reported previously. The 6.0 meV mode is inconsistent with expectations for magnetic excitations in the usual spin-ladder model. Our results imply that VOPO must be described by a different magnetic Hamiltonian than the simple Heisenberg antiferromagnetic spin ladder. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,THEORET & COMPUTAT PHYS SECT,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RP Garrett, AW (reprint author), UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611, USA. RI Nagler, Stephen/B-9403-2010; Nagler, Stephen/E-4908-2010 OI Nagler, Stephen/0000-0002-7234-2339 NR 18 TC 39 Z9 39 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 6 BP 3631 EP 3635 DI 10.1103/PhysRevB.55.3631 PG 5 WC Physics, Condensed Matter SC Physics GA WJ875 UT WOS:A1997WJ87500052 ER PT J AU Campbell, CE Clements, BE Krotscheck, E Saarela, M AF Campbell, CE Clements, BE Krotscheck, E Saarela, M TI Thermodynamics of boson quantum films SO PHYSICAL REVIEW B LA English DT Article ID HE-4 FILMS; GROUND-STATE; HEAT-CAPACITY; HELIUM FILMS; LIQUID-HE-4; STABILITY; GRAPHITE; DENSITY; ENERGY; FLUIDS AB Theoretical studies of films of liquid He-4 adsorbed to strongly attractive plane substrates indicate that the growth of such films occurs through a sequence of first-order phase transitions-''layering transitions''-which are a direct consequence of the short-range, hard-core-like interaction between individual helium atoms. The present work examines the effects of temperature on these transitions. At given temperatures, the spinodal points and phase coexistence boundaries are determined for the transitions. Increasing the temperature tends to decrease the coverage span of the transition regions, signaling the possible existence of a critical point terminating the two-phase equilibrium. The layering transitions depend strongly on the helium-substrate potential; the longer-range helium-magnesium potential yields fewer transitions and noticeably lower transition temperatures than the helium-graphite potential. The temperature dependence of the chemical potential, third sound, static structure function, heat capacities, and superfluid densities are reported. The heat capacities are compared to those measured by Greywall and Busch [Phys Rev. Lett. 67, 3535 (1991)]. The thermal broadening of the film's density profile is also discussed. We find that below 1.2 K, thermal broadening is quite weak for coverages away from the layering transitions. The monolayer film experiences the least broadening whereas double-layer and triple-layer films broaden by increasing the local density in the outer tail of their density profiles, while depleting the local density in the inner portion of the outermost layer. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. JOHANNES KEPLER UNIV,INST THEORET PHYS,A-4040 LINZ,AUSTRIA. UNIV OULU,DEPT PHYS SCI THEORET PHYS,SF-90570 OULU,FINLAND. RP Campbell, CE (reprint author), UNIV MINNESOTA,SCH PHYS & ASTRON,MINNEAPOLIS,MN 55455, USA. NR 56 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 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 6 BP 3769 EP 3791 DI 10.1103/PhysRevB.55.3769 PG 23 WC Physics, Condensed Matter SC Physics GA WJ875 UT WOS:A1997WJ87500072 ER PT J AU Vilk, YM AF Vilk, YM TI Shadow features and shadow bands in the paramagnetic state of cuprate superconductors SO PHYSICAL REVIEW B LA English DT Article ID RANGE ANTIFERROMAGNETIC CORRELATIONS; FERMI-SURFACE; COEXISTENCE; METALLICITY; YBA2CU3O7; PHASE AB The conditions for the precursors of antiferromagnetic bands in cuprate superconductors are studied using a weak-to-intermediate coupling approach. It is shown that there are, in fact, three different precursor effects due to the proximity to antiferromagnetic instability: (i) the shadow band which is associated with a pole in the Green's function, (ii) the dispersive shadow feature due to the thermal enhancement of the scattering rate, and (iii) the nondispersive shadow feature due to quantum spin fluctuation that exists only in a (k) over right arrow scan of the spectral function A(omega(fixed),(k) over right arrow). I found that dispersive shadow peaks in A(omega,(k) over right arrow) can-exist at finite temperature T in the renormalized classical regime, when T much greater than omega(sf), xi(AFM) > xi(th) = nu(F)/T (omega(sf) is the characteristic energy of spin fluctuations, xi(th) is the thermal wavelength of electron). In contrast at zero temperature, only a nondispersive shadow feature in A(omega(fixed),(k) over right arrow) has been found. I found, however, that the latter effect is always very small. The theory predicts no shadow effects in the optimally doped materials. The conditions for which shadow peaks can be observed in photoemission are discussed. RP Vilk, YM (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 17 TC 34 Z9 34 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 6 BP 3870 EP 3875 DI 10.1103/PhysRevB.55.3870 PG 6 WC Physics, Condensed Matter SC Physics GA WJ875 UT WOS:A1997WJ87500083 ER PT J AU Kuntscher, CA Bendele, GM Stephens, PW AF Kuntscher, CA Bendele, GM Stephens, PW TI Alkali-metal stoichiometry and structure of K4C60 and Rb4C60 SO PHYSICAL REVIEW B LA English DT Article ID RAY-POWDER DIFFRACTION; INTERCALATION COMPOUNDS; ELECTRONIC-STRUCTURE; C-60; SUPERCONDUCTIVITY; FULLERIDES; FULLERENES; DYNAMICS; AXC60; A4C60 AB Alkali-metal fulleride samples KxC60 and RbxC60 with stoichiometries close to x=4 were examined with x-ray powder-diffraction measurements at room temperature. We have shown through Rietveld refinements that A(4)C(60) is a line phase with charge per lattice site that is closer to integer than in any other fulleride. The C-60 molecules are disordered between two possible orientations within the body-centered-tetragonal lattice with the three orthogonal twofold rotation axes aligned with the unit-cell translation vectors in space group I4/mmm. The x-ray diffraction results exclude any quadrupole distortion of the fullerene molecule beyond about 0.04 Angstrom. These results suggest that K4C60 and Rb4C60 may be Mott insulators. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Kuntscher, CA (reprint author), SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794, USA. NR 32 TC 43 Z9 43 U1 1 U2 8 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 6 BP R3366 EP R3369 PG 4 WC Physics, Condensed Matter SC Physics GA WJ875 UT WOS:A1997WJ87500012 ER PT J AU Len, PM Gog, T Fadley, CS Materlik, G AF Len, PM Gog, T Fadley, CS Materlik, G TI X-ray fluorescence holography and multiple-energy x-ray holography: A critical comparison of atomic images SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-EMISSION HOLOGRAPHY; PHOTOELECTRON DIFFRACTION; AUGER-ELECTRON; SCATTERING; PATTERNS; CRYSTALLOGRAPHY; RECONSTRUCTION; INTENSITIES; INVERSION AB We compare x-ray fluorescence holography (XFH) and multiple-energy x-ray holography (MEXH), two techniques that have recently been used to obtain experimental three-dimensional atomic images. For single-energy holograms, these methods are equivalent by virtue of the optical reciprocity theorem. However, XFH can only record holographic information at the characteristic fluorescence energies of the emitting species, while MEXH can record holographic information at any energy above the fluorescent edge of the emitter, thus enabling the suppression of real-twin overlaps and other aberrations and artifacts in atomic images. C1 OAK RIDGE NATL LAB,UPTON,NY 11973. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. HAMBURGER SYNCHROTRONSTRAHLUNGSLAB HASYLAB,D-22603 HAMBURG,GERMANY. DESY,D-22603 HAMBURG,GERMANY. RP Len, PM (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. NR 35 TC 36 Z9 36 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD FEB 1 PY 1997 VL 55 IS 6 BP R3323 EP R3327 PG 5 WC Physics, Condensed Matter SC Physics GA WJ875 UT WOS:A1997WJ87500001 ER PT J AU Ma, L Karwowski, HJ Brune, CR Ayer, Z Black, TC Blackmon, JC Ludwig, EJ Viviani, M Kievsky, A Schiavilla, R AF Ma, L Karwowski, HJ Brune, CR Ayer, Z Black, TC Blackmon, JC Ludwig, EJ Viviani, M Kievsky, A Schiavilla, R TI Measurements of H-1((d)over-right-arrow,gamma)(3)He and H-2((p)over-right-arrow,gamma)He-3 at very low energies SO PHYSICAL REVIEW C LA English DT Article ID FEW-BODY NUCLEI; ELASTIC-SCATTERING; CROSS-SECTION; P-D; CAPTURE; DEUTERIUM AB Angular distributions of the analyzing powers iT(11), T-20, and T-22 for H-1((d) over right arrow,gamma)He-3 at 40 less than or equal to E(c.m.)less than or equal to 110 keV and the angular distribution of the analyzing power A(y) for H-2((p) over right arrow,gamma)He-3 at 70 less than or equal to E(c.m.)less than or equal to 210 keV have been measured for the first time. In addition, absolute differential cross sections for proton-deuteron capture have been determined for E(c.m.) = 75, 108, 133, and 173 keV. Thick ice or heavy ice targets and two large-volume, high-purity Ge gamma-ray detectors were used. Results are in general agreement with an exact three-body calculation utilizing a realistic nucleon-nucleon potential. The vector-polarization observables are found to be especially sensitive to meson-exchange-current effects. The extracted S(0) value for proton-deuteron capture is similar to 25% lower than that presently used in astrophysical calculations. An expression for the thermonuclear reaction rate below 10 GK is given. C1 TRIANGLE UNIV NUCL LAB,DURHAM,NC 27708. IST NAZL FIS NUCL,I-56100 PISA,ITALY. JEFFERSON LAB THEOR GRP,NEWPORT NEWS,VA 23606. OLD DOMINION UNIV,DEPT PHYS,NORFOLK,VA 23529. RP Ma, L (reprint author), UNIV N CAROLINA,DEPT PHYS & ASTRON,CHAPEL HILL,NC 27599, USA. RI kievsky, alejandro/A-7123-2011 NR 40 TC 46 Z9 46 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 FEB PY 1997 VL 55 IS 2 BP 588 EP 596 DI 10.1103/PhysRevC.55.588 PG 9 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500010 ER PT J AU Johnson, NR Wells, JC Akovali, Y Baktash, C Bengtsson, R Brinkman, MJ Cullen, DM Gross, CJ Jin, HQ Lee, LY Macchiavelli, AO McGowan, FK Milner, WT Yu, CH AF Johnson, NR Wells, JC Akovali, Y Baktash, C Bengtsson, R Brinkman, MJ Cullen, DM Gross, CJ Jin, HQ Lee, LY Macchiavelli, AO McGowan, FK Milner, WT Yu, CH TI Lifetimes of high-spin states in the pi i(13/2) band of Re-173 SO PHYSICAL REVIEW C LA English DT Article ID INTRUDER BANDS; DEFORMATIONS; ALIGNMENT; ISOTOPES; NUCLEI; YB-166; RE AB Lifetime measurements on the i(13/2) band built on the proton configuration 1/2(+)[660] in Re-173 have been carried out by the Doppler-broadened line shape method with the use of the GAMMASPHERE array in an early-implementation arrangement. Lifetimes of the stretched E2 transitions from states of spin 41/2(+)-69/2(+) in this band were measured, and the transition quadrupole moments calculated from these lifetimes are consistent (average Q(1)=8.1+/-0.5 eb) with a large and near-constant deformation (beta(2) approximate to 0.29) over the frequency range of <(h)over bar omega> 0.29-0.47 MeV. This result attests to the strong deformation-driving effect of the intruder pi i(13/2) orbital when it lies just above the Fermi surface. From thin-target measurements, it was possible to add three new levels to this band and to determine that the experimental aligned angular momenta gradually evolve over a large frequency range and level off with a total gain characteristic of alignment by i(13/2) neutrons. Calculations carried out for diabatic configurations give a satisfactory accounting of the alignment gain. However, because of the large interaction between crossing bands, a more meaningful description of the deformation pattern in this band was achieved through calculations of the spin-adiabatic type. Both calculations are discussed and compared with the experimental results. C1 JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. TENNESSEE TECHNOL UNIV,COOKEVILLE,TN 38505. OAK RIDGE ASSOCIATED UNIV,ORISE,OAK RIDGE,TN 37830. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. UNIV ROCHESTER,ROCHESTER,NY 14627. RP Johnson, NR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 28 TC 21 Z9 21 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 FEB PY 1997 VL 55 IS 2 BP 652 EP 659 DI 10.1103/PhysRevC.55.652 PG 8 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500016 ER PT J AU Capurro, OA DiGregorio, DE Gil, S Abriola, D diTada, M Niello, JOF Macchiavelli, AO Marti, GV Pacheco, AJ Testoni, JE Tomasi, D Urteaga, I AF Capurro, OA DiGregorio, DE Gil, S Abriola, D diTada, M Niello, JOF Macchiavelli, AO Marti, GV Pacheco, AJ Testoni, JE Tomasi, D Urteaga, I TI Average angular momentum in compound nucleus reactions deduced from isomer ratio measurements SO PHYSICAL REVIEW C LA English DT Article ID NEAR-BARRIER FUSION; HEAVY-ION REACTIONS; SUBBARRIER FUSION; CROSS-SECTIONS; COULOMB BARRIER; DISTRIBUTIONS; ENERGIES AB We have measured the ratio of the yields for the metastable and ground states of Te-119 produced in the fusion-evaporation reactions Pd-110(C-12,3n) and In-115(Li-7,3n) by off-line observation of delayed gamma-ray emission. The absolute cross sections for the formation of the metastable (J(pi) = 11/2(-), Tin = 4.68 d) and ground (J(pi) = 1/2(+), T-1/2 = 16.05 h) states were determined at energies close to the Coulomb barrier for both systems. We have deduced the average angular momentum from these isomer ratio measurements through statistical model calculations. The deduced mean angular momentum agrees quite well with those calculated by a simple fusion model. The expected constant value of thr average total angular momentum at subbarrier energies was confirmed for the C-12+ Pd-110 system. The predicted variation of the mean orbital angular momentum with the reduced mass of the entrance channel was also verified. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Capurro, OA (reprint author), COMIS NACL ENERGIA ATOM,DEPT FIS,LAB TANDAR,RA-1429 BUENOS AIRES,DF,ARGENTINA. NR 28 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 FEB PY 1997 VL 55 IS 2 BP 766 EP 774 DI 10.1103/PhysRevC.55.766 PG 9 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500030 ER PT J AU Bardayan, DW daCruz, MTF Hindi, MM Barghouty, AF Chan, YD Garcia, A Larimer, RM Lesko, KT Norman, EB Rossi, DF Wietfeldt, FE Zlimen, I AF Bardayan, DW daCruz, MTF Hindi, MM Barghouty, AF Chan, YD Garcia, A Larimer, RM Lesko, KT Norman, EB Rossi, DF Wietfeldt, FE Zlimen, I TI Radioisotope yields from 1.85-GeV protons on Mo and 1.85- and 5.0-GeV protons on Te SO PHYSICAL REVIEW C LA English DT Article ID CROSS-SECTIONS; COSMIC-RAYS AB Radioisotope yields from 1.85-GeV proton interactions in a natural isotopic composition Mo target and those from 1.85- and 5.0-GeV protons in natural Te targets were measured at Lawrence Berkeley National Laboratory's Bevatron. The radioisotope yields were determined by gamma-counting the targets using 100-cm(3) coaxial Ge detectors following the irradiations. Cross sections were determined for the production of 36 radioactive nuclides, ranging from Z=35, A=74 to Z=43, A=97, from the Mo target and for 43 radioactive nuclides, ranging from Z=35, A=75 to Z=53, A=130 from the Te targets. The average deviations of the experimental cross sections from those predicted by the semiempirical isotopic cross sections of Silberberg and Tsao were 53% for p+Mo at 1.85 GeV, 66% for p+Te at 1.85 GeV, and 35% for p+Te at 5.0 GeV. These deviations are higher than those found previously for medium and heavy targets and for elemental cross sections. The minimum production cross section of Nb-91, which may be of interest as a cosmic-ray chronometer, was found to be 18+/-3 mb for the p+Mo reaction. C1 TENNESSEE TECHNOL UNIV,DEPT PHYS,COOKEVILLE,TN 38505. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. ROANOKE COLL,DEPT PHYS,SALEM,VA 24153. OI Garcia, Alejandro/0000-0001-6056-6645 NR 19 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 FEB PY 1997 VL 55 IS 2 BP 820 EP 827 DI 10.1103/PhysRevC.55.820 PG 8 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500036 ER PT J AU Williams, RA Small, TM AF Williams, RA Small, TM TI Extracting F-2(Lambda)(q(2))/F-2(Sigma Lambda)(q(2)) from p(e,e'K+)(Lambda)over-right-arrow/(Sigma)over-right-arrow(0) polarizations? SO PHYSICAL REVIEW C LA English DT Article ID ELECTROMAGNETIC STRUCTURE; MODEL; BARYONS AB In kaon electroproduction, p(e,e'K+)Y (Y=Lambda,Sigma(0)) hyperon polarization is an observable which arises from interference between resonant (N*,Delta*) and nonresonant amplitudes involving the hyperon anomalous sn magnetic form factors F-2(Lambda)(q(2)) and F-2(Sigma Lambda)(q(2)). Within the framework of an effective hadronic held Lagrangian model we investigate the possibility suggested by Williams and Truman that the Lambda/Sigma(0) polarized cross section ratio may be approximately proportional to the form factor ratio F-2(Lambda)/F-2(Sigma Lambda) and independent of the dominant N* amplitude. We illustrate both the simplified case where the relation between the form factor and polarized cross section ratio is an identity and the sensitivity due to dynamical assumptions about nearby resonances and the g(KN Lambda) coupling constant. C1 THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606. NR 15 TC 2 Z9 2 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD FEB PY 1997 VL 55 IS 2 BP 882 EP 889 DI 10.1103/PhysRevC.55.882 PG 8 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500042 ER PT J AU Frankfurt, L Lee, TSH Miller, GA Strikman, M AF Frankfurt, L Lee, TSH Miller, GA Strikman, M TI Chiral transparency SO PHYSICAL REVIEW C LA English DT Article ID PERTURBATION-THEORY; NUCLEAR TRANSPARENCY; EXCLUSIVE PROCESSES; COLOR TRANSPARENCY; BAG MODEL; INTERMEDIATE Q(2); MOMENTUM-TRANSFER; FORM-FACTORS; QUARK; QCD AB Color transparency is the vanishing of initial and final state interactions, predicted by QCD to occur in high momentum transfer quasielastic nuclear reactions. For specific reactions involving nucleons, the initial and final state interactions are expected to be dominated by exchanges of pions. We argue that these interactions are also suppressed in high momentum transfer nuclear quasielastic reactions; this is ''chiral transparency.'' We show that studies of the e He-3-->e' Delta(++)nn reaction could reveal the influence of chiral transparency. C1 INST PHYS NUCL,ST PETERSBURG,RUSSIA. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802. RP Frankfurt, L (reprint author), TEL AVIV UNIV,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. NR 53 TC 7 Z9 7 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD FEB PY 1997 VL 55 IS 2 BP 909 EP 916 DI 10.1103/PhysRevC.55.909 PG 8 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500045 ER PT J AU Mercer, DJ Austin, SM Glagola, BG AF Mercer, DJ Austin, SM Glagola, BG TI Suggested correction to He-6, Li-6,Li-7, and Be-7 production cross sections in alpha+alpha reactions between 60 and 160 MeV SO PHYSICAL REVIEW C LA English DT Article ID LI AB Reanalysis of alpha + alpha reaction data at 61.5, 80.8, 118.9, 139.2, and 158.2 MeV [B.G. Glagola et al., Phys. Rev. C 25, 34 (1982)] suggests that inconsistent normalizations have been used for calculating cross sections for He-6, Li-6,Li-7, and Be-7 production. Corrected values are presented, notably for Li-6, which may have significant implications for astrophysics calculations. C1 UNIV COLORADO,PHYS NUCL LAB,BOULDER,CO 80309. MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. NR 15 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD FEB PY 1997 VL 55 IS 2 BP 946 EP 949 DI 10.1103/PhysRevC.55.946 PG 4 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500049 ER PT J AU Schlei, BR AF Schlei, BR TI Space-time extensions from space-time densities and Bose-Einstein correlations SO PHYSICAL REVIEW C LA English DT Article ID HEAVY-ION COLLISIONS; HIGH-ENERGY COLLISIONS; RELATIVISTIC HYDRODYNAMICS; PION INTERFEROMETRY; EXPANSION AB Using a (3 + 1)-dimensional solution of the relativistic Euler-equations for Pb+Pb at 160A GeV, space-time extensions of kaon emission zones are calculated from space-time densities and compared to the inverse widths of two-kaon Bose-Einstein correlation functions. The comparison shows a satisfactory agreement and it is concluded that because of the Gaussian shape of the kaon correlation functions, the space-time parameters of the kaon source can be calculated directly from space-time densities. In the case of intensity interferometry of identical pions this simplification is not recommended when applying Gaussian fits because of the present strong effects of resonance decays. The whale discussion is based on the assumption that hadron emission in ultrarelativistic heavy-ion collisions is purely chaotic or that coherence is at least negligible. RP Schlei, BR (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 22 TC 6 Z9 6 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 FEB PY 1997 VL 55 IS 2 BP 954 EP 957 DI 10.1103/PhysRevC.55.954 PG 4 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500051 ER PT J AU Brenner, DS Zamfir, NV Casten, RF AF Brenner, DS Zamfir, NV Casten, RF TI Shell closure at N=164: Spherical or deformed? Reply SO PHYSICAL REVIEW C LA English DT Letter ID STABILITY AB The spherical basis for the P factor is emphasized and its applicability to the transactinide elements is discussed in light of the enhanced stability found in this region. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. YALE UNIV,NEW HAVEN,CT 06520. INST ATOM PHYS,R-76900 BUCHAREST,MAGURELE,ROMANIA. RP Brenner, DS (reprint author), CLARK UNIV,WORCESTER,MA 01610, USA. RI Zamfir, Nicolae Victor/F-2544-2011 NR 12 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 0556-2813 J9 PHYS REV C JI Phys. Rev. C PD FEB PY 1997 VL 55 IS 2 BP 974 EP 975 DI 10.1103/PhysRevC.55.974 PG 2 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500057 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 Exploring the F-18(p,gamma)Ne-19 gateway to the formation of heavy elements in hot stars SO PHYSICAL REVIEW C LA English DT Article ID RADIOACTIVE ION-BEAM AB An upper limit to the production of Ne-19 through the F-18(p,gamma) reaction at the recently discovered s-wave resonance has been determined. The limit implies that in a hot stellar environment (T-9>0.5) this reaction is not a significant gateway from the hot CNO cycle towards the production of heavier elements in stars. C1 HEBREW UNIV JERUSALEM,IL-91904 JERUSALEM,ISRAEL. UNIV WISCONSIN,MADISON,WI 53706. NORTHWESTERN UNIV,EVANSTON,IL 60208. RP Rehm, KE (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 19 TC 28 Z9 28 U1 0 U2 5 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 FEB PY 1997 VL 55 IS 2 BP R566 EP R569 DI 10.1103/PhysRevC.55.R566 PG 4 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500004 ER PT J AU Zyromski, KE Loveland, W Souliotis, GA Morrissey, DJ Powell, CF Batenkov, O Aleklett, K Yanez, R Forsberg, I SanchezVega, M Dunn, JR Glagola, BG AF Zyromski, KE Loveland, W Souliotis, GA Morrissey, DJ Powell, CF Batenkov, O Aleklett, K Yanez, R Forsberg, I SanchezVega, M Dunn, JR Glagola, BG TI Fusion enhancement with neutron-rich radioactive beams SO PHYSICAL REVIEW C LA English DT Article ID COUPLED-CHANNEL CODE; HEAVY-ION REACTIONS; EVEN-EVEN NUCLIDES; CROSS-SECTIONS; DEFORMATIONS; ELEMENTS; NUCLEI; STATE AB We measured the fusion-fission excitation functions for the S-32+Ta-181 reaction and the S-38+Ta-181 reaction. (The radioactive S-38 beam was produced by projectile fragmentation.) The thresholds were measured to be 137.5+/-1.0 and 130.7+/-2.0 MeV for the S-32 and S-38-induced reactions, respectively. This result agrees with the systematics of fusion excitation functions and may be significant in the synthesis of new heavy nuclei. C1 MICHIGAN STATE UNIV,NATL SUPERCOND CYCLOTRON LAB,E LANSING,MI 48824. VG KHLOPIN RADIUM INST,ST PETERSBURG 197022,RUSSIA. UNIV UPPSALA,DEPT NEUTRON RES,S-75105 UPPSALA,SWEDEN. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Zyromski, KE (reprint author), OREGON STATE UNIV,DEPT CHEM,GILBERT HALL 153,CORVALLIS,OR 97331, USA. NR 27 TC 33 Z9 33 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 FEB PY 1997 VL 55 IS 2 BP R562 EP R565 DI 10.1103/PhysRevC.55.R562 PG 4 WC Physics, Nuclear SC Physics GA WJ465 UT WOS:A1997WJ46500003 ER PT J AU Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, N Wang, C Wang, CH Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, 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 Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S AF Abe, F Akimoto, H Akopian, A Albrow, MG Amendolia, SR Amidei, D Antos, J AnwayWiese, C Aota, S Apollinari, G Asakawa, T Ashmanskas, W Atac, M Azfar, F AzziBacchetta, P Bacchetta, N Badgett, W Bagdasarov, S Bailey, MW Bao, J deBarbaro, P BarbaroGaltieri, A Barnes, VE Barnett, BA Barzi, E Bauer, G Baumann, T Bedeschi, F Behrends, S Belforte, S Bellettini, G Bellinger, J Benjamin, D Benlloch, J Bensinger, J Benton, D Beretvas, A Berge, JP Berryhill, J Bertolucci, S Bevensee, B Bhatti, A Biery, K Binkley, M Bisello, D Blair, RE Blocker, C Bodek, A Bokhari, W Bolognesi, V Bolla, G Bortoletto, D Boudreau, J Breccia, L Bromberg, C Bruner, N BuckleyGeer, E Budd, HS Burkett, K Busetto, G ByonWagner, A Byrum, KL Cammerata, J Campagnari, C Campbell, M Caner, A Carithers, W Carlsmith, D Castro, A Cauz, D Cen, Y Cervelli, F Chang, PS Chang, PT Chao, HY Chapman, J Cheng, MT Chiarelli, G Chikamatsu, T Chiou, CN Christofek, L Cihangir, S Clark, AG Cobal, M Cocca, E Contreras, M Conway, J Cooper, J Cordelli, M Couyoumtzelis, C Crane, D CroninHennessy, D Culbertson, R Daniels, T DeJongh, F Delchamps, S DellAgnello, S DellOrso, M Demina, R Demortier, L Denby, B Deninno, M Derwent, PF Devlin, T Dittmann, JR Donati, S Done, J Dorigo, T Dunn, A Eddy, N Einsweiler, K Elias, JE Ely, R Engels, E Errede, D Errede, S Fan, Q Ferretti, C Fiori, I Flaugher, B Foster, GW Franklin, M Frautschi, M Freeman, J Friedman, J Fuess, TA Fukui, Y Funaki, S Gagliardi, G Galeotti, S Gallinaro, M GarciaSciveres, M Garfinkel, AF Gay, C Geer, S Gerdes, DW Giannetti, P Giokaris, N Giromini, P Giusti, G Gladney, L Glenzinski, D Gold, M Gonzalez, J Gordon, A Goshaw, AT Goulianos, K Grassmann, H Groer, L GrossoPilcher, C Guillian, G Guo, RS Haber, C Hafen, E Hahn, SR Hamilton, R Handler, R Hans, RM Hara, K Hardman, AD Harral, B Harris, RM Hauger, SA Hauser, J Hawk, C Hayashi, E Heinrich, J Hoffman, KD Hohlmann, M Holck, C Hollebeek, R Holloway, L Holscher, A Hong, S Houk, G Hu, P Huffman, BT Hughes, R Huston, J Huth, J Hylen, J Ikeda, H Incagli, M Incandela, J Introzzi, G Iwai, J Iwata, Y Jensen, H Joshi, U Kadel, RW Kajfasz, E Kambara, H Kamon, T Kaneko, T Karr, K Kasha, H Kato, Y Keaffaber, TA Keeble, L Kelley, K Kennedy, RD Kephart, R Kesten, P Kestenbaum, D Keup, RM Keutelian, H Keyvan, F Kharadia, B Kim, BJ Kim, DH Kim, HS Kim, SB Kim, SH Kim, YK Kirsch, L Koehn, P Kondo, K Konigsberg, J Kopp, S Kordas, K Korytov, A Koska, W Kovacs, E Kowald, W Krasberg, M Kroll, J Kruse, M Kuwabara, T Kuhlmann, SE Kuns, E Laasanen, AT Labanca, N Lammel, S Lamoureux, JI LeCompte, T Leone, S Lewis, JD Limon, P Lindgren, M Liss, TM Lockyer, N Long, O Loomis, C Loreti, M Lu, J Lucchesi, D Lukens, P Lusin, S Lys, J Maeshima, K Maghakian, A Maksimovic, P Mangano, M Mansour, J Mariotti, M Marriner, JP Martin, A Matthews, JAJ Mattingly, R McIntyre, P Melese, P Menzione, A Meschi, E Metzler, S Miao, C Miao, T Michail, G Miller, R Minato, H Miscetti, S Mishina, M Mitsushio, H Miyamoto, T Miyashita, S Moggi, N Morita, Y Mueller, J Mukherjee, A Muller, T Murat, P Nakada, H Nakano, I Nelson, C Neuberger, D NewmanHolmes, C Ninomiya, M Nodulman, L Oh, SH Ohl, KE Ohmoto, T Ohsugi, T Oishi, R Okabe, M Okusawa, T Oliveira, R Olsen, J Pagliarone, C Perazzo, A Pescara, L Peters, MD Phillips, TJ Piacentino, G Pillai, M Pitts, KT Plunkett, R Pondrom, L Proudfoot, J Ptohos, F Punzi, G Ragan, K Reher, D Ribon, A Rimondi, F Ristori, L Robertson, WJ Rodrigo, T Rolli, S Romano, J Rosenson, L Roser, R Sakumoto, WK Saltzberg, D Sansoni, A Santi, L Sato, H Schlabach, P Schmidt, EE Schmidt, MP Scribano, A Segler, S Seidel, S Seiya, Y Sganos, G Shapiro, MD Shaw, NM Shen, Q Shepard, PF Shimojima, M Shochet, M Siegrist, J Sill, A Sinervo, P Singh, P Skarha, J Sliwa, K Snider, FD Song, T Spalding, J Speer, T Sphicas, P Spinella, F Spiropulu, M Spiegel, L Stanco, L Steele, J Stefanini, A Strahl, K Strait, J Strohmer, R Stuart, D Sullivan, G Soumarokov, A Sumorok, K Suzuki, J Takada, T Takahashi, T Takano, T Takikawa, K Tamura, N Tartarelli, F Taylor, W Teng, PK Teramoto, Y Tether, S Theriot, D Thomas, TL Thun, R Timko, M Tipton, P Titov, A Tkaczyk, S Toback, D Tollefson, K Tollestrup, A deTroconiz, JF Truitt, S Tseng, J Turini, N Uchida, T Uemura, N Ukegawa, F Unal, G Valls, J vandenBrink, SC Vejcik, S Velev, G Vidal, R Vondracek, M Vucinic, D Wagner, RG Wagner, RL Wahl, J Wallace, N Wang, C Wang, CH Wang, J Wang, MJ Wang, QF Warburton, A Watts, T Webb, R Wei, C Wendt, 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 Ye, Y Yeh, GP Yeh, P Yin, M Yoh, J Yosef, C Yoshida, T Yovanovitch, D Yu, I Yu, L Yun, JC Zanetti, A Zetti, F Zhang, L Zhang, W Zucchelli, S TI Observation of Lambda(b)(0)->J/psi Lambda at the Fermilab proton-antiproton collider SO PHYSICAL REVIEW D LA English DT Article ID QUARK PRODUCTION; LAMBDA-B; COLLISIONS; LIFETIME; DETECTOR; DECAYS AB The decay Lambda(b)(0) --> J/psi Lambda is observed in 110 pb(-1) of p (p) over bar collisions taken at root s = 1.8 TeV. These data are used to measure a Lambda(b)(0) mass of 5621+/-4(stat)+/-3(syst) MeV/c(2), and a mass difference between the Lambda(b)(0) and the B-0 of 340+/-5(stat)+/-1(syst) MeV/c(2). The production cross-section times branching fraction for the decay Lambda(b)(0) --> J/psi Lambda relative to that for the decay B-0 --> J/psi K-S(0) has been measured to be 0.27+/-0.12(stat)+/-0.05(syst). C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV BOLOGNA,IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. BRANDEIS UNIV,WALTHAM,MA 02254. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV CHICAGO,CHICAGO,IL 60637. DUKE UNIV,DURHAM,NC 27708. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV GENEVA,CH-1211 GENEVA 4,SWITZERLAND. HARVARD UNIV,CAMBRIDGE,MA 02138. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. UNIV ILLINOIS,URBANA,IL 61801. MCGILL UNIV,INST PARTICLE PHYS,MONTREAL,PQ H3A 2T8,CANADA. UNIV TORONTO,TORONTO,ON M5S 1A7,CANADA. JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. MIT,CAMBRIDGE,MA 02139. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. UNIV NEW MEXICO,ALBUQUERQUE,NM 87131. OHIO STATE UNIV,COLUMBUS,OH 43210. OSAKA CITY UNIV,OSAKA 588,JAPAN. UNIV PADUA,IST NAZL FIS NUCL,SEZIONE PADOVA,I-35131 PADUA,ITALY. UNIV PENN,PHILADELPHIA,PA 19104. UNIV PISA,IST NAZL FIS NUCL,I-56100 PISA,ITALY. SCUOLA NORMALE SUPER PISA,I-56100 PISA,ITALY. UNIV PITTSBURGH,PITTSBURGH,PA 15260. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ROCHESTER,ROCHESTER,NY 14627. ROCKEFELLER UNIV,NEW YORK,NY 10021. RUTGERS STATE UNIV,PISCATAWAY,NJ 08854. ACAD SINICA,TAIPEI 11529,TAIWAN. TEXAS A&M UNIV,COLLEGE STN,TX 77843. TEXAS TECH UNIV,LUBBOCK,TX 79409. UNIV TSUKUBA,TSUKUBA,IBARAKI 305,JAPAN. TUFTS UNIV,MEDFORD,MA 02155. UNIV WISCONSIN,MADISON,WI 53706. YALE UNIV,NEW HAVEN,CT 06511. RP Abe, F (reprint author), NATL LAB HIGH ENERGY PHYS,KEK,TSUKUBA,IBARAKI 305,JAPAN. RI Vucinic, Dejan/C-2406-2008; Azzi, Patrizia/H-5404-2012; Punzi, Giovanni/J-4947-2012; Chiarelli, Giorgio/E-8953-2012; Warburton, Andreas/N-8028-2013; Kim, Soo-Bong/B-7061-2014; 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 27 TC 48 Z9 48 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD FEB 1 PY 1997 VL 55 IS 3 BP 1142 EP 1152 DI 10.1103/PhysRevD.55.1142 PG 11 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700007 ER PT J AU Armstrong, TA Bettoni, D Bharadwaj, V Biino, C Borreani, G Broemmelsiek, D Buzzo, A Calabrese, R Ceccucci, A Cester, R Church, M Dalpiaz, P Dalpiaz, PF Dimitroyannis, D Fabbri, M Fast, J Gianoli, A Ginsburg, CM Gollwitzer, K Govi, G Hahn, A Hasan, M Hsueh, S Lewis, R Luppi, E Macri, M Majewska, AM Mandelkern, M Marchetto, F Marinelli, M Marques, J Marsh, W Martini, M Masuzawa, M Menichetti, E Migliori, A Mussa, R Palestini, S Pallavicini, M Passaggio, S Pastrone, N Patrignani, C Peoples, J Petrucci, F Pia, MG Pordes, S Rapidis, P Ray, R Reid, J Rinaudo, G Robutti, E Roccuzzo, B Rosen, J Santroni, A Sarmiento, M Savrie, M Schultz, J Seth, KK Smith, AJ Smith, GA Sozzi, M Trokenheim, S Weber, MF Werkema, S Zhang, Y Zhao, J Zioulas, G AF Armstrong, TA Bettoni, D Bharadwaj, V Biino, C Borreani, G Broemmelsiek, D Buzzo, A Calabrese, R Ceccucci, A Cester, R Church, M Dalpiaz, P Dalpiaz, PF Dimitroyannis, D Fabbri, M Fast, J Gianoli, A Ginsburg, CM Gollwitzer, K Govi, G Hahn, A Hasan, M Hsueh, S Lewis, R Luppi, E Macri, M Majewska, AM Mandelkern, M Marchetto, F Marinelli, M Marques, J Marsh, W Martini, M Masuzawa, M Menichetti, E Migliori, A Mussa, R Palestini, S Pallavicini, M Passaggio, S Pastrone, N Patrignani, C Peoples, J Petrucci, F Pia, MG Pordes, S Rapidis, P Ray, R Reid, J Rinaudo, G Robutti, E Roccuzzo, B Rosen, J Santroni, A Sarmiento, M Savrie, M Schultz, J Seth, KK Smith, AJ Smith, GA Sozzi, M Trokenheim, S Weber, MF Werkema, S Zhang, Y Zhao, J Zioulas, G TI Measurement of the branching ratios psi'->e(+)e(-), psi'->J/psi pi pi, and psi'->J/psi eta SO PHYSICAL REVIEW D LA English DT Article ID ANNIHILATION; CALORIMETER; DECAY AB We have observed exclusive decays of the psi' in an experiment where the psi' is formed in antiproton-proton annihilations. We report the branching ratios B(psi' --> e(+)e(-)) = (8.3 +/- 0.5(stat) +/- 0.7(syst)) x 10(-3), B(psi' --> J/psi pi(+)pi(-)) = 0.283 +/- 0.021(stat) +/- 0.020(syst), B(psi' --> J/psi pi(0) pi(0)) = 0.184 +/- 0.019(stat) +/- 0.013(syst), B(pi' --> J/psi eta) = 0.032 +/- 0.010(stat) +/- 0.002(syst). C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. INST NAZL FIS NUCL,I-44100 FERRARA,ITALY. UNIV FERRARA,I-44100 FERRARA,ITALY. INST NAZL FIS NUCL,I-16146 GENOA,ITALY. UNIV GENOA,I-16146 GENOA,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV CALIF IRVINE,IRVINE,CA 92717. INST NAZL FIS NUCL,I-10125 TURIN,ITALY. UNIV TURIN,I-10125 TURIN,ITALY. RP Armstrong, TA (reprint author), PENN STATE UNIV,UNIVERSITY PK,PA 16802, USA. RI Pia, Maria Grazia/C-7034-2012; Sozzi, Marco/H-1674-2011; Patrignani, Claudia/C-5223-2009; Gianoli, Alberto/H-5544-2015; Luppi, Eleonora/A-4902-2015; Calabrese, Roberto/G-4405-2015; Pallavicini, Marco/G-5500-2012 OI Pia, Maria Grazia/0000-0002-3579-9639; Sozzi, Marco/0000-0002-2923-1465; Patrignani, Claudia/0000-0002-5882-1747; Gianoli, Alberto/0000-0002-2456-8667; Luppi, Eleonora/0000-0002-1072-5633; Calabrese, Roberto/0000-0002-1354-5400; Pallavicini, Marco/0000-0001-7309-3023 NR 20 TC 20 Z9 20 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 FEB 1 PY 1997 VL 55 IS 3 BP 1153 EP 1158 DI 10.1103/PhysRevD.55.1153 PG 6 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700008 ER PT J AU Grosnick, DP Hill, DA Kasprzyk, T Lopiano, D Ohashi, Y Sheppard, J Shima, T Spinka, H Stanek, R Underwood, DG Yokosawa, A Bystricky, J Chaumette, P Deregel, J Durand, G Fabre, J Lehar, F deLesquen, A vanRossum, L Luehring, FC Miller, DH Shanahan, P Krueger, KW Cossairt, JD Read, AL Iwatani, K Rykov, VL Solovyanov, VL Vasiliev, AN Akchurin, N Onel, Y Maki, T Enyo, H Funahashi, H Goto, Y Iijima, T Imai, K Itow, Y Makino, S Masaike, A Miyake, K Nagamine, T Saito, N Yamashita, S Takashima, R Takeuchi, F Kuroda, K Michalowicz, A Tanaka, N Salvato, G Villari, A Tamura, N Yoshida, T Corcoran, MD Cranshaw, J NessiTedaldi, F Nessi, M Nguyen, C Roberts, JB Skeens, J White, JL Bravar, A Penzo, A Schiavon, P Pauletta, G AF Grosnick, DP Hill, DA Kasprzyk, T Lopiano, D Ohashi, Y Sheppard, J Shima, T Spinka, H Stanek, R Underwood, DG Yokosawa, A Bystricky, J Chaumette, P Deregel, J Durand, G Fabre, J Lehar, F deLesquen, A vanRossum, L Luehring, FC Miller, DH Shanahan, P Krueger, KW Cossairt, JD Read, AL Iwatani, K Rykov, VL Solovyanov, VL Vasiliev, AN Akchurin, N Onel, Y Maki, T Enyo, H Funahashi, H Goto, Y Iijima, T Imai, K Itow, Y Makino, S Masaike, A Miyake, K Nagamine, T Saito, N Yamashita, S Takashima, R Takeuchi, F Kuroda, K Michalowicz, A Tanaka, N Salvato, G Villari, A Tamura, N Yoshida, T Corcoran, MD Cranshaw, J NessiTedaldi, F Nessi, M Nguyen, C Roberts, JB Skeens, J White, JL Bravar, A Penzo, A Schiavon, P Pauletta, G TI Measurement of the differences in the total cross section for antiparallel and parallel longitudinal spins and a measurement of parity nonconservation with incident polarized protons and antiprotons at 200 GeV/c SO PHYSICAL REVIEW D LA English DT Review ID DELTA-SIGMA-L; COULOMB-NUCLEAR INTERFERENCE; PURE HELICITY STATES; P-P SCATTERING; 6 GEV-C; ANALYZING POWER; PRECISION-MEASUREMENT; VIOLATING ASYMMETRY; ELASTIC-SCATTERING; HIGH-ENERGIES AB The highest-energy measurement of Delta sigma(L)(pp) and the first ever measurement of Delta sigma(L)((p) over bar p), the differences between proton-proton and antiproton-proton total cross sections for pure longitudinal spin states, are described. Data were taken using 200-GeV/c polarized beams incident on a polarized-proton target. The results are measured to be Delta sigma(L)(pp) = -42 +/- 48(stat) +/- 53(syst) mu b and Delta sigma(L)((p) over bar p) = -256 +/- 124(stat) +/- 109(syst) mu b. Many tests of systematic effects were investigated and are described, and a comparison to theoretical predictions is also given. Measurements of parity nonconservation at 200 GeV/c in proton scattering and the first ever of antiproton scattering have also been derived from these data. The values are consistent with zero at the 10(-5) level. C1 CENS,DAPNIA,F-91191 GIF SUR YVETTE,FRANCE. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60201. FT HAYS STATE UNIV,DEPT PHYS,HAYS,KS 67601. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. HIROSHIMA UNIV,FAC ENGN,HIGASHIHIROSHIMA 724,JAPAN. INST HIGH ENERGY PHYS,SERPUKHOV,RUSSIA. UNIV IOWA,DEPT PHYS,IOWA CITY,IA 52242. UNIV OCCUPAT & ENVIRONM HLTH,KITAKYUSHU,FUKUOKA 807,JAPAN. KYOTO UNIV,DEPT PHYS,KYOTO 60601,JAPAN. KYOTO UNIV,KYOTO 612,JAPAN. KYOTO SANGYO UNIV,KYOTO 612,JAPAN. PHYS PARTICULES LAB,F-74017 ANNECY LE VIEUX,FRANCE. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV MESSINA,DIPARTIMENTO FIS,I-98100 MESSINA,ITALY. OKAYAMA UNIV,DEPT PHYS,OKAYAMA 800,JAPAN. OSAKA CITY UNIV,OSAKA 558,JAPAN. RICE UNIV,TW BONNER NUCL LAB,HOUSTON,TX 77251. UNIV TRIESTE,DIPARTIMENTO FIS,I-34100 TRIESTE,ITALY. UNIV UDINE,I-33100 UDINE,ITALY. RP Grosnick, DP (reprint author), ARGONNE NATL LAB,ARGONNE,IL 60439, USA. NR 137 TC 17 Z9 17 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD FEB 1 PY 1997 VL 55 IS 3 BP 1159 EP 1187 DI 10.1103/PhysRevD.55.1159 PG 29 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700009 ER PT J AU Randrup, J AF Randrup, J TI Statistical properties of the linear sigma model used in dynamical simulations of DCC formation SO PHYSICAL REVIEW D LA English DT Article ID DISORIENTED CHIRAL CONDENSATE; HIGH-ENERGY; PHASE-TRANSITION; FINITE-TEMPERATURE; EMULSION CHAMBERS; NUCLEAR COLLISIONS; QUANTUM EVOLUTION; FAMILIES; BEHAVIOR; DOMAINS AB The present work develops a simple approximate framework for initializing and interpreting dynamical simulations with the linear sigma model exploring the formation of disoriented chiral condensates in high-energy collisions. By enclosing the system in a rectangular box with periodic boundary conditions, it is possible to decompose uniquely the chiral field into its spatial average (the order parameter) and its fluctuations (the quasiparticles) which can be treated in the Hartree approximation. The quasiparticle modes are then described approximately by Klein-Gordon dispersion relations containing an effective mass depending on both the temperature and the magnitude of the order parameter; their fluctuations are instrumental in shaping the effective potential governing the order parameter, and the emerging statistical description is thermodynamicially consistent. The temperature dependence of the statistical distribution of the order parameter is discussed, as is the behavior of the associated effective masses; as the system is cooled, the field fluctuations subside, causing a smooth change from the high-temperature phase in which chiral symmetry is approximately restored towards the normal phase. Of practical interest is the fact that the equilibrium field configurations can be sampled in a simple manner, thus providing a convenient means for specifying the initial conditions in dynamical simulations of the nonequilibrium relaxation of the chiral field; in particular, the correlation function is much more realistic than those emerging in previous initialization methods. It is illustrated how such samples remain approximately invariant under propagation by the unapproximated equation of motion over times that are long on the scale of interest, thereby suggesting that the treatment is sufficiently accurate to be of practical utility. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. NR 42 TC 54 Z9 54 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD FEB 1 PY 1997 VL 55 IS 3 BP 1188 EP 1205 DI 10.1103/PhysRevD.55.1188 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700010 ER PT J AU Jadach, S Skrzypek, M Ward, BFL AF Jadach, S Skrzypek, M Ward, BFL TI Soft-pair corrections to low-angle Bhabha scattering: YFS Monte Carlo approach SO PHYSICAL REVIEW D LA English DT Article ID QED VERTEX CORRECTION AB We use our recently derived real and virtual infrared functions for soft pairs in QED in the YFS exponentiation framework to develop a Monte Carlo event generator realization of the effects of such pairs in the low-angle Bhabha scattering process at SLC or CERN LEP energies. The respective Monte Carlo realization is incorporated into the event generator BHLUMI 2.30, and explicit Monte Carlo data are presented for the ALEPH LCAL luminometer-type acceptance. Our results confirm our earlier semianalytic estimates of the size of such effects in the SLC or LEP luminosity process and provide an event-by-event view of their manifestations. C1 CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. INST NUCL PHYS,KRAKOW,POLAND. RP Jadach, S (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 19 TC 38 Z9 38 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD FEB 1 PY 1997 VL 55 IS 3 BP 1206 EP 1215 DI 10.1103/PhysRevD.55.1206 PG 10 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700011 ER PT J AU Goshtasbpour, M Ramsey, GP AF Goshtasbpour, M Ramsey, GP TI What we can learn about nucleon spin structure from recent data SO PHYSICAL REVIEW D LA English DT Article ID GENERATED PARTON DISTRIBUTIONS; HIGH-ENERGY COLLISIONS; BJORKEN SUM-RULE; GLUON POLARIZATION; PROTON; QCD; SCATTERING; DEUTERON; ELECTROPRODUCTION; ASYMMETRY AB We have used recent data from the CERN and SLAG to extract information about nucleon spin structure. We find that the SMC proton data on integral(0)(1)g(1)(p)dx, the E142 neutron data on integral(0)(1)g(1)(n)dx, and the deuteron data from the SMC and E143 give different results for fractions of the spin carried by each of the constituents. These appear to lead to two different and incompatible models for the polarized strange sea. The polarized gluon distribution occurring in the gluon anomaly does not have to be large in order to be consistent with either set of experimental data. However, it appears that the discrepancies in the implications of these data cannot be resolved with any simple theoretical arguments. We conclude that more experiments must be performed in order to adequately determine the fraction of spin carried by each of the nucleon constituents. C1 SHAHID BEHESHTI UNIV, DEPT PHYS, TEHRAN, IRAN. LOYOLA UNIV, DEPT PHYS, CHICAGO, IL 60626 USA. ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. RP AEOI, CTR THEORET PHYS & MATH, TEHRAN, IRAN. NR 66 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 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD FEB 1 PY 1997 VL 55 IS 3 BP 1244 EP 1252 DI 10.1103/PhysRevD.55.1244 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700015 ER PT J AU Lai, HL Huston, J Kuhlmann, S Olness, F Owens, J Soper, D Tung, WK Weerts, H AF Lai, HL Huston, J Kuhlmann, S Olness, F Owens, J Soper, D Tung, WK Weerts, H TI Improved parton distributions from global analysis of recent deep inelastic scattering and inclusive jet data SO PHYSICAL REVIEW D LA English DT Article ID DEUTERON STRUCTURE FUNCTIONS; HIGH STATISTICS MEASUREMENT; DIRECT PHOTON PRODUCTION; MUON SCATTERING; HIGH Q2; PROTON; QCD; COLLISIONS AB The impact of recent precision measurements of DIS structure functions and inclusive jet production at the Fermilab Tevatron on the global QCD analysis of parton distribution functions is studied in detail. Particular emphasis is placed on exploring the range of variation of the gluon distribution G(x, Q) allowed by these new data. The strong coupling of G(x, Q) with alpha(s) is fully taken into account. A new generation of CTEQ parton distributions, CTEQ4, is presented. It consists of the three standard sets [modified minimal subtraction (<(MS)over bar>), deep inelastic scattering (DIS), and leading order (LO)], a series that gives a range of parton distributions with corresponding alpha(s)'s, and a set with a low starting value of Q. Previously obtained gluon distributions that are consistent with the high E(t) jet cross section are also discussed in the context of this new global analysis. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. SO METHODIST UNIV,DALLAS,TX 75275. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV OREGON,EUGENE,OR 97403. RP Lai, HL (reprint author), MICHIGAN STATE UNIV,E LANSING,MI 48824, USA. NR 46 TC 852 Z9 852 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 FEB 1 PY 1997 VL 55 IS 3 BP 1280 EP 1296 DI 10.1103/PhysRevD.55.1280 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700020 ER PT J AU Feng, JL Strassler, MJ AF Feng, JL Strassler, MJ TI Measuring SUSY parameters at CERN LEP II using chargino production and decay SO PHYSICAL REVIEW D LA English DT Article ID STANDARD MODEL; E+E COLLISIONS; SUPERSYMMETRY; PHYSICS; BOSONS AB Previously, in the context of the minimal supersymmetric standard model (without a priori assumptions of parameter unification), we studied the constraints on weak-scale SUSY parameters from chargino production at CERN LEP II, using as observables m(<(chi)over tilde>1+/-), m(<(chi)over tilde>10) the cross section and the leptonic branching fraction. Here, exploiting the high degree of polarization in chargino production, we add to our earlier work the forward-backward asymmetries of the visible hadrons and leptons in chargino decays. For a chargino that is mostly gaugino, the parameter space can now be restricted to a small region; tan beta is constrained, the soft electroweak gaugino and electron sneutrino masses are determined to about 10%, and the sign of mu may be determined. Constraints for a chargino that is mostly Higgsino are much weaker, but still disfavor the hypothesis that the chargino is mostly gaugino. For a chargino which is a roughly equal mixture of Higgsino and gaugino, we find intermediate results. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RUTGERS STATE UNIV,DEPT PHYS & ASTRON,PISCATAWAY,NJ 08855. RP Feng, JL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. NR 33 TC 24 Z9 24 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 FEB 1 PY 1997 VL 55 IS 3 BP 1326 EP 1342 DI 10.1103/PhysRevD.55.1326 PG 17 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700024 ER PT J AU Ambrosanio, S Kane, GL Kribs, GD Martin, SP Mrenna, S AF Ambrosanio, S Kane, GL Kribs, GD Martin, SP Mrenna, S TI Low energy supersymmetry with a neutralino LSP and the CDF ee gamma gamma+E(T) event SO PHYSICAL REVIEW D LA English DT Article ID STANDARD MODEL; RADIATIVE-CORRECTIONS; E+E ANNIHILATION; HIGGS SECTOR; DECAY; PHYSICS; MASSES; SEARCHES; MATRIX; MSSM AB We present a refined and expanded analysis of the CDF eeyy+E(T) event as superpartner production, assuming the lightest neutralino is the lightest supersymmetric particle. A general low energy Lagrangian is constrained by a minimum cross section times branching ratio into two electrons and two photons, kinematics consistent with the event, and LEP 1-LEP 130 data. We examine how the supersymmetric parameters depend on the kinematics, branching ratios, and experimental predictions with a selectron interpretation of the event, and discuss to what extent these are modified by other interpretations. Predictions for imminent CERN LEP upgrades and the present and future Fermilab Tevatron are presented. Finally, we briefly discuss the possible connection to other phenomena including a light top squark, the neutralino relic density, the shift in R(b), and the associated shift in alpha(s), and implications for the form of the theory. C1 ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. RP UNIV MICHIGAN, RANDALL LAB PHYS, ANN ARBOR, MI 48109 USA. NR 55 TC 53 Z9 53 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 FEB 1 PY 1997 VL 55 IS 3 BP 1372 EP 1398 DI 10.1103/PhysRevD.55.1372 PG 27 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700028 ER PT J AU Baer, H Chen, CH Tata, X AF Baer, H Chen, CH Tata, X TI Impact of hadronic decays of the lightest neutralino on the reach of the CERN LHC SO PHYSICAL REVIEW D LA English DT Article ID SOLAR NEUTRINO OSCILLATIONS; R-PARITY VIOLATION; SUPERSYMMETRIC MODELS; BOUNDS; SUPERGRAVITY; SIGNATURES; COUPLINGS; COLLIDER; BREAKING; MASSES AB If R parity is not conserved, the lightest supersymmetric particle could decay via lepton-number-violating or baryon-number-violating interactions; The latter case is particularly insidious since it leads to a reduction of the E(T) as well as leptonic signals for supersymmetry. We evaluate cross sections for jets plus E(T), 1l, 2l (same sign and opposite sign), and 3l event topologies that result from the simultaneous production of all sparticles at the CERN Large Hadron Collider (LHC), assuming that the lightest supersymmetric particle (Z) over tilde(\) decays hadronically inside the detector via R-parity-violating interactions. We assume that these interactions do not affect the production rates or decays of other sparticles. We examine the SUSY reach of the LHC for this ''pessimistic'' scenario, and show that experiments at the LHC will still be able to search for gluinos and squarks as heavy as 1 TeV, given just 10 fb(-1) of integrated luminosity, even with cuts designed to explore the canonical SUSY framework with a conserved R parity. C1 LAWRENCE LIVERMORE NATL LAB,DAVIS INST HIGH ENERGY PHYS,DAVIS,CA 95616. UNIV HAWAII,DEPT PHYS & ASTRON,HONOLULU,HI 96822. RP Baer, H (reprint author), FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306, USA. NR 33 TC 29 Z9 29 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 FEB 1 PY 1997 VL 55 IS 3 BP 1466 EP 1470 DI 10.1103/PhysRevD.55.1466 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700035 ER PT J AU He, HJ Kilgore, WB AF He, HJ Kilgore, WB TI Equivalence theorem and its radiative-correction-free formulation for all R(xi) gauges SO PHYSICAL REVIEW D LA English DT Article ID ELECTROWEAK SYMMETRY-BREAKING; PRECISE FORMULATION; STANDARD MODEL; WW SCATTERING; TOP-QUARK; RENORMALIZATION; COUPLINGS; BOSONS; SECTOR; COLLIDERS AB The electroweak equivalence theorem quantitatively connects the physical amplitudes of longitudinal massive gauge bosons to those of-the corresponding unphysical would-be Goldstone bosons. Its precise form depends on both the gauge-fixing condition and the renormalization scheme. Our previous modification-free schemes have applied to a broad class of R(xi) gauges including the 't Hooft-Feynman gauge but excluding the Landau gauge. In this paper we construct a new renormalization scheme;in which the radiative modification factor C-mod(a) is equal to unity for all R(xi) gauges, including both 't Hooft-Feynman and Landau gauges. This scheme makes C-mod(a) equal to unity by specifying a convenient subtraction condition for the would-be Goldstone boson wave function renormalization constant Z(phi)a. We build the new scheme for both the standard model and the effective Lagrangian formulated electroweak theories (with either linearly or nonlinearly realized symmetry-breaking sector). Based upon these, a new prescription, called the ''divided equivalence theorem,'' is further proposed for extending the high energy region applicable to the equivalence theorem. C1 FERMILAB NATL ACCELERATOR LAB,DEPT THEORET PHYS,BATAVIA,IL 60510. RP He, HJ (reprint author), DESY,DIV THEORY,D-22603 HAMBURG,GERMANY. NR 50 TC 39 Z9 39 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 FEB 1 PY 1997 VL 55 IS 3 BP 1515 EP 1532 DI 10.1103/PhysRevD.55.1515 PG 18 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700041 ER PT J AU Garisto, R Wells, JD AF Garisto, R Wells, JD TI Constraints on supersymmetric soft phases from renormalization group relations SO PHYSICAL REVIEW D LA English DT Article ID ELECTRIC-DIPOLE MOMENT; SPONTANEOUS CP VIOLATION; QUARK PAIR PRODUCTION; STANDARD-MODEL; TOP-QUARK; WEAK DECAYS; NEUTRON; PHYSICS; SUPERGRAVITY; BARYOGENESIS AB By using relations derived from renormalization group equations (RGEs), we find that strnog indirect constraints can be placed on the top squark mixing phase in A(t) from the electric dipole moment of the neutron (d(n)). Since m(t) is large, any GUT-scale phase in A(t) feeds into other weak scale phases through RGEs, which in turn contribute to d(n). Thus CP-violating effects due to a weak-scale A(t) are strongly constrained. We find that \Im A(t)(EW)\ must be smaller than or of order \Im B-EW\, making the electric dipole moment of the top quark unobservably small in most models. Quantitative estimates of the contributions to d(n) from A(u), A(d), and B show that substantial fine-tuning is still required to satisfy the experimental bound on d(n). While the low energy phases of the A's are not as strongly constrained as the phase of B-EW, we note that the phase of a universal A(GUT) induces large contributions in the phase of B-EW through RGEs, and is thus still strongly constrained in most models with squark masses below a TeV. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Garisto, R (reprint author), BROOKHAVEN NATL LAB,BNL THEORY GRP,BLDG 510A,UPTON,NY 11973, USA. OI Garisto, Robert/0000-0002-1204-2035 NR 73 TC 65 Z9 65 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 FEB 1 PY 1997 VL 55 IS 3 BP 1611 EP 1622 DI 10.1103/PhysRevD.55.1611 PG 12 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700047 ER PT J AU Avery, P Prescott, C Yang, S Yelton, J Brandenburg, G Briere, RA Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Karliner, I Palmer, M Selen, M Thaler, JJ Edwards, KW Ogg, M Bellerive, A Britton, DI Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Copty, N Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Kim, IJ Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Duboscq, JE Fulton, R Fujino, D Gan, KK Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A White, C Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Athanas, M Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Lange, DJ Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Lohner, M Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Dumas, DJ Ehrlich, R Elia, R Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Jones, CD Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Soffer, A Ward, C AF Avery, P Prescott, C Yang, S Yelton, J Brandenburg, G Briere, RA Liu, T Saulnier, M Wilson, R Yamamoto, H Browder, TE Li, F Rodriguez, JL Bergfeld, T Eisenstein, BI Ernst, J Gladding, GE Gollin, GD Karliner, I Palmer, M Selen, M Thaler, JJ Edwards, KW Ogg, M Bellerive, A Britton, DI Janicek, R MacFarlane, DB McLean, KW Patel, PM Sadoff, AJ Ammar, R Baringer, P Bean, A Besson, D Coppage, D Copty, N Davis, R Hancock, N Kotov, S Kravchenko, I Kwak, N Anderson, S Kubota, Y Lattery, M ONeill, JJ Patton, S Poling, R Riehle, T Smith, A Savinov, V Alam, MS Athar, SB Kim, IJ Ling, Z Mahmood, AH Severini, H Timm, S Wappler, F Duboscq, JE Fulton, R Fujino, D Gan, KK Honscheid, K Kagan, H Kass, R Lee, J Sung, M Undrus, A White, C Wanke, R Wolf, A Zoeller, MM Nemati, B Richichi, SJ Ross, WR Skubic, P Wood, M Bishai, M Fast, J Gerndt, E Hinson, JW Miller, DH Shibata, EI Shipsey, IPJ Yurko, M Gibbons, L Johnson, SD Kwon, Y Roberts, S Thorndike, EH Jessop, CP Lingel, K Marsiske, H Perl, ML Schaffner, SF Wang, R Coan, TE Fadeyev, V Korolkov, I Maravin, Y Narsky, I Shelkov, V Stroynowski, R Staeck, J Volobouev, I Ye, J Artuso, M Efimov, A Gao, M Goldberg, M Greene, R He, D Kopp, S Moneti, GC Mountain, R Mukhin, Y Skwarnicki, T Stone, S Xing, X Bartelt, J Csorna, SE Jain, V Marka, S Freyberger, A Gibaut, D Kinoshita, K Lai, IC Pomianowski, P Schrenk, S Bonvicini, G Cinabro, D Barish, B Chadha, M Chan, S Eigen, G Miller, JS OGrady, C Schmidtler, M Urheim, J Weinstein, AJ Wurthwein, F Asner, DM Athanas, M Bliss, DW Brower, WS Masek, G Paar, HP Gronberg, J Korte, CM Lange, DJ Kutschke, R Menary, S Morrison, RJ Nakanishi, S Nelson, HN Nelson, TK Qiao, C Richman, JD Roberts, D Ryd, A Tajima, H Witherell, MS Balest, R Behrens, BH Cho, K Ford, WT Lohner, M Park, H Rankin, P Roy, J Smith, JG Alexander, JP Bebek, C Berger, BE Berkelman, K Bloom, K Cassel, DG Cho, HA Coffman, DM Crowcroft, DS Dickson, M Drell, PS Dumas, DJ Ehrlich, R Elia, R Gaidarev, P Galik, RS Gittelman, B Gray, SW Hartill, DL Heltsley, BK Jones, CD Jones, SL Kandaswamy, J Katayama, N Kim, PC Kreinick, DL Lee, T Liu, Y Ludwig, GS Masui, J Mevissen, J Mistry, NB Ng, CR Nordberg, E Patterson, JR Peterson, D Riley, D Soffer, A Ward, C TI Search for phi mesons in tau lepton decay SO PHYSICAL REVIEW D LA English DT Article ID C(1480) MESON; DETECTOR; VEPP-2M; LIBRARY; MASS AB We report results from a direct search for tau(-) --> phi h(-)nu(tau)(h(-) = pi(-) or K-) using 3.1 fb(-1) of data collected with the CLEO II detector. We find model-dependent upper limits on the branching fractions in the range beta(tau(-) --> phi pi(-)nu(tau)) < (1.2 - 2.0) x 10(-4) and beta(tau(-) --> phi K(-)nu(tau)) < (5.4 - 6.7) x 10(-5) at 90% confidence level. C1 HARVARD UNIV, CAMBRIDGE, MA 02138 USA. UNIV HAWAII MANOA, HONOLULU, HI 96822 USA. UNIV ILLINOIS, CHAMPAIGN, IL 61801 USA. CARLETON UNIV, OTTAWA, ON K1S 5B6, CANADA. MCGILL UNIV, MONTREAL, PQ H3A 2T8, CANADA. INST PARTICLE PHYS, MONTREAL, PQ, CANADA. ITHACA COLL, ITHACA, NY 14850 USA. UNIV KANSAS, LAWRENCE, KS 66045 USA. UNIV MINNESOTA, MINNEAPOLIS, MN 55455 USA. SUNY ALBANY, ALBANY, NY 12222 USA. OHIO STATE UNIV, COLUMBUS, OH 43210 USA. UNIV OKLAHOMA, NORMAN, OK 73019 USA. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. UNIV ROCHESTER, ROCHESTER, NY 14627 USA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. SO METHODIST UNIV, DALLAS, TX 75275 USA. SYRACUSE UNIV, SYRACUSE, NY 13244 USA. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. VIRGINIA POLYTECH INST & STATE UNIV, BLACKSBURG, VA 24061 USA. WAYNE STATE UNIV, DETROIT, MI 48202 USA. CALTECH, PASADENA, CA 91125 USA. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV COLORADO, BOULDER, CO 80309 USA. CORNELL UNIV, ITHACA, NY 14853 USA. RP UNIV FLORIDA, GAINESVILLE, FL 32611 USA. RI Schaffner, Stephen/D-1189-2011; Britton, David/F-2602-2010; Briere, Roy/N-7819-2014 OI Britton, David/0000-0001-9998-4342; Briere, Roy/0000-0001-5229-1039 NR 25 TC 4 Z9 4 U1 1 U2 1 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 FEB 1 PY 1997 VL 55 IS 3 BP R1119 EP R1123 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700001 ER PT J AU Blum, T DeTar, C Gottlieb, S Rummukainen, K Heller, UM Hetrick, JE Toussaint, D Sugar, RL Wingate, M AF Blum, T DeTar, C Gottlieb, S Rummukainen, K Heller, UM Hetrick, JE Toussaint, D Sugar, RL Wingate, M TI Improving flavor symmetry in the Kogut-Susskind hadron spectrum SO PHYSICAL REVIEW D LA English DT Article ID WILSON FERMIONS; LATTICE ACTION; QCD AB We study the effect of modifying the coupling of Kogut-Susskind quarks to the gauge field by replacing the link matrix in the quark action by a ''fat link,'' or sum of link plus three-link paths. Flavor symmetry breaking, determined by the mass difference between the Goldstone and non-Goldstone local pions, is reduced by approximately a factor of 2 by this modification. C1 UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. INDIANA UNIV, DEPT PHYS, BLOOMINGTON, IN 47405 USA. FLORIDA STATE UNIV, SUPERCOMP COMPUTAT RES INST, TALLAHASSEE, FL 32306 USA. UNIV ARIZONA, DEPT PHYS, TUCSON, AZ 85721 USA. UNIV CALIF SANTA BARBARA, DEPT PHYS, SANTA BARBARA, CA 93106 USA. UNIV COLORADO, DEPT PHYS, BOULDER, CO 80309 USA. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. NR 24 TC 103 Z9 103 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 FEB 1 PY 1997 VL 55 IS 3 BP R1133 EP R1137 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700005 ER PT J AU Mohapatra, RN Riotto, A AF Mohapatra, RN Riotto, A TI Anomalous U(1)-mediated supersymmetry breaking, fermion masses, and natural suppression of, FCNC and CP-violating effects SO PHYSICAL REVIEW D LA English DT Article ID MIXING ANGLES; SUPERGRAVITY; SYMMETRIES; NEUTRON AB We construct realistic supergravity models where supersymmetry breaking arises from the D terms of an anomalous U(1) gauge symmetry broken at the Planck scale. The model has the attractive feature that the gaugino masses, the A terms, and the mass splittings between the like-charged squarks of the first two generations compared to their average masses (i.e., Delta m((q) over tilde)(2)/m((q) over tilde)(2)) are all suppressed. As a result, the electric dipole moment of the neutron as well as the flavor-changing neutral current effects are predicted to be naturally small. We show how some versions of these models can lead to the expected value of the mu and B mu terms and qualitatively explain the observed mass hierarchy among quarks and leptons. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Mohapatra, RN (reprint author), UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 29 TC 34 Z9 34 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 FEB 1 PY 1997 VL 55 IS 3 BP R1138 EP R1141 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF297 UT WOS:A1997WF29700006 ER PT J AU Takeno, S Peyrard, M AF Takeno, S Peyrard, M TI Nonlinear rotating modes: Green's-function solution SO PHYSICAL REVIEW E LA English DT Article ID LOCALIZED MODES; SCATTERING AB Lattice Green's functions are used to investigate localized rotating modes recently exhibited in some nonlinear lattices. For a one-dimensional lattice, analytical expressions of the solution are obtained, first in the rotating-wave approximation and then by including higher-order terms. Numerical simulations confirm the validity of these solutions. The method is not restricted to one-dimensional lattices. C1 ECOLE NORMALE SUPER LYON,PHYS LAB,CNRS,URA 1325,F-69007 LYON,FRANCE. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Takeno, S (reprint author), OSAKA INST TECHNOL,FAC INFORMAT SCI,DEPT INFORMAT SYST,1-79-1 KITAYAMA,HIRAKATA,OSAKA 57301,JAPAN. RI PEYRARD, Michel/C-8494-2014 NR 15 TC 20 Z9 20 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 FEB PY 1997 VL 55 IS 2 BP 1922 EP 1928 DI 10.1103/PhysRevE.55.1922 PG 7 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WK492 UT WOS:A1997WK49200088 ER PT J AU McKinstrie, CJ Smalyuk, VA Giacone, RE Vu, HX AF McKinstrie, CJ Smalyuk, VA Giacone, RE Vu, HX TI Power exchange between crossed laser beams and the associated frequency cascade SO PHYSICAL REVIEW E LA English DT Article ID STIMULATED BRILLOUIN-SCATTERING; PLASMA AB The power exchange between crossed laser beams made possible by an ion-acoustic wave is studied, as is the associated frequency cascade. The beam evolution is found to depend sensitively on whether the beams are monochromatic or multichromatic initially, and whether their intersection region lies partially or completely within the plasma. C1 UNIV ROCHESTER,LASER ENERGET LAB,ROCHESTER,NY. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP McKinstrie, CJ (reprint author), UNIV ROCHESTER,DEPT MECH ENGN,ROCHESTER,NY 14627, USA. RI McKinstrie, Colin/L-7879-2013 NR 12 TC 9 Z9 9 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1063-651X J9 PHYS REV E JI Phys. Rev. E PD FEB PY 1997 VL 55 IS 2 BP 2044 EP 2047 DI 10.1103/PhysRevE.55.2044 PG 4 WC Physics, Fluids & Plasmas; Physics, Mathematical SC Physics GA WK492 UT WOS:A1997WK49200108 ER PT J AU Dilmanian, FA Wu, XY Parsons, EC Ren, B Kress, J Button, TM Chapman, LD Coderre, JA Giron, F Greenberg, D Krus, DJ Liang, Z Marcovici, S Petersen, MJ Roque, CT Shleifer, M Slatkin, DN Thomlinson, WC Yamamoto, K Zhong, Z AF Dilmanian, FA Wu, XY Parsons, EC Ren, B Kress, J Button, TM Chapman, LD Coderre, JA Giron, F Greenberg, D Krus, DJ Liang, Z Marcovici, S Petersen, MJ Roque, CT Shleifer, M Slatkin, DN Thomlinson, WC Yamamoto, K Zhong, Z TI Single- and dual-energy CT with monochromatic synchrotron x-rays SO PHYSICS IN MEDICINE AND BIOLOGY LA English DT Article ID COMPUTED-TOMOGRAPHY; CORONARY ANGIOGRAPHY; SMALL SAMPLES; RADIATION; RESOLUTION AB We explored the potential for clinical research of computed tomography (CT) with monochromatic x-rays using the preclinical multiple energy computed tomography (MECT) system at the National Synchrotron Light Source. MECT has a Bred, horizontal fan beam with a subject apparatus rotating about a vertical axis; it will be used for imaging the human head and neck. Two CdWO4-photodiode array detectors with different spatial resolutions were used. A 10.5 cm diameter acrylic phantom was imaged with MECT at 43 keV and with a conventional CT (CCT) at 80 kVp: spatial resolution approximate to 6.5 line pairs (lp)/cm for both; slice height, 2.6 mm for MECT against 3.0 mm for CCT; surface dose, 3.1 cGy for MECT against 2.0 cGy for CCT. The resultant image noise was 1.5 HU for MECT against 3 HU for CCT. Computer simulations of the same images with more precisely matched spatial resolution, slice height and dose indicated an image-noise ratio of 1.4:1.0 for CCT against MECT. A 13.5 cm diameter acrylic phantom imaged with MECT at approximate to 0.1 keV above the iodine K edge and with CCT showed, for a 240 mu g l ml(-1) solution, an image contrast of 26 HU for MECT and 13 and 9 HU for the 80 and 100 kVp CCT, respectively. The corresponding numbers from computer simulation of the same images were 26, 12, and 9 HU, respectively. MECT's potential for use in clinical research is discussed. C1 SUNY STONY BROOK,STONY BROOK,NY 11794. ANAL CORP,PEABODY,MA 01960. HAMAMATSU PHOTON KK,HAMAMATSU,SHIZUOKA 43132,JAPAN. BICRON,HARSHAW CRYSTAL PROD GRP,SOLON,OH 44139. RP Dilmanian, FA (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Chapman, Dean/I-6168-2013 OI Chapman, Dean/0000-0001-6590-4156 NR 28 TC 77 Z9 79 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0031-9155 J9 PHYS MED BIOL JI Phys. Med. Biol. PD FEB PY 1997 VL 42 IS 2 BP 371 EP 387 DI 10.1088/0031-9155/42/2/009 PG 17 WC Engineering, Biomedical; Radiology, Nuclear Medicine & Medical Imaging SC Engineering; Radiology, Nuclear Medicine & Medical Imaging GA WJ042 UT WOS:A1997WJ04200009 PM 9044419 ER PT J AU Morita, A Ono, Y Katsurai, M Yamada, M Yoshikawa, S AF Morita, A Ono, Y Katsurai, M Yamada, M Yoshikawa, S TI Experimental investigation on tilt stabilizing effect of external toroidal field in low aspect ratio tokamak SO PHYSICS OF PLASMAS LA English DT Article ID MAGNETIC RECONNECTION; PLASMAS AB This paper describes experimental investigations on the equilibrium and global stability of low aspect ratio tokamaks with different aspect ratios ranging from 1.1 to 1.9. The Z-theta pinch spheromak formation technique is used to produce low aspect ratio tokamaks in an external toroidal field generated by the center conductor. Using this operation, the plasma stability has been investigated in the transition regime from tokamaks to spheromaks. It has been found that there exists a lower critical value of the center conductor current to surpress the global plasma instability of the n = 1 tilt and/or shift modes. The ratio of this critical current to plasma current is experimentally measured for the first time as a function of the aspect ratio. Glass-tube cylindrical limiters with different radii are installed along the symmetric center axis of the Spherical Torus-3 device [Y. Ono et al., Phys. Fluids B 5, 3691 (1993)]. As the aspect ratio is decreased from 1.9 to 1.1, it is observed that the critical ratio of the center conductor current to plasma current decreases from 1.2 to 0.2. The safety factor q at the plasma edge corresponding to this critical current is roughly 1.5 to 3.0. Similar experiments are also carried out with a thin metal cover surrounding the surface of the glass tube limiter. The thin metal cover permits the decrease in the critical current and the corresponding edge q value of q similar to 1. These experimental results of the critical current ratio are found to be comparable to that predicted from theoretical models where the restoring force against the tilt motion is considered to be generated by the interaction of the external toroidal field with the n = 1 induced surface currents in the tilt motion. (C) 1997 American Institute of Physics. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Morita, A (reprint author), UNIV TOKYO,FAC ENGN,DEPT ELECT ENGN,BUNKYO KU,7-3-1 HONGO,TOKYO 113,JAPAN. RI Yamada, Masaaki/D-7824-2015 OI Yamada, Masaaki/0000-0003-4996-1649 NR 22 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 315 EP 322 DI 10.1063/1.872092 PG 8 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900009 ER PT J AU Isler, RC Wood, RW Klepper, CC Brooks, NH Fenstermacher, ME Leonard, AW AF Isler, RC Wood, RW Klepper, CC Brooks, NH Fenstermacher, ME Leonard, AW TI Spectroscopic characterization of the DIII-D divertor SO PHYSICS OF PLASMAS LA English DT Article ID RADIATIVE LOSSES; MAGNETIC-FIELDS; JT-60U; PLASMA; IMPURITY; TOKAMAK; CONFINEMENT; DESIGN AB Radiative losses along a fixed view into the divertor chamber of the DIII-D tokamak [Plasma Physics Controlled Nuclear Fusion Research 1986 (International Atomic Energy Agency, Vienna, 1987), Vol I, p. 159] have been characterized for attached and partially detached discharges by analyzing line-integrated vacuum ultraviolet (VUV) signals, Essentially all the emission can be ascribed to carbon and deuterium. Because the majority of the most intense lines, which lie at wavelengths above 1100 Angstrom, are not accessible to the present instrumentation, extensive use has been made of collisional-radiative (CR) calculations for level populations of the important ions in order to relate the total radiated power to shorter wavelength transitions. In beam-heated plasmas? the fraction of radiation detected from carbon along the VUV spectrometer view is usually between 50% and 80% of the total. Carbon densities are estimated from a simplified approach to modelling the emission using a one-dimensional transport code. For partially detached plasmas the concentrations range from 2%-6% of the electron density; but in attached plasmas it appears that carbon may supply most of the electrons in the divertor region just below the X point. Ion temperatures are measured from Doppler broadening of spectral lines by fitting measured profiles to theoretical lineshapes, which account precisely for atomic sublevel splitting caused by the Zeeman/Paschen-Back effect in the tokamak magnetic field. (C) 1997 American Institute of Physics. C1 GEN ATOM CO, SAN DIEGO, CA 92186 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 95540 USA. RP Isler, RC (reprint author), OAK RIDGE NATL LAB, OAK RIDGE, TN 37830 USA. OI Isler, Ralph/0000-0002-5368-7200 NR 29 TC 48 Z9 48 U1 1 U2 2 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 355 EP 368 DI 10.1063/1.872095 PG 14 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900014 ER PT J AU Wong, KL Majeski, R Petrov, M Rogers, JH Schilling, G Wilson, JR Berk, HL Breizman, BN Pekker, M Wong, HV AF Wong, KL Majeski, R Petrov, M Rogers, JH Schilling, G Wilson, JR Berk, HL Breizman, BN Pekker, M Wong, HV TI Evolution of toroidal Alfven eigenmode instability in Tokamak Fusion Test Reactor SO PHYSICS OF PLASMAS LA English DT Article ID DEUTERIUM-TRITIUM EXPERIMENTS; TFTR; STABILITY; BEAM; EXCITATION; DRIVEN; SATURATION; PLASMAS; WAVES; IONS AB The nonlinear behavior of the toroidal Alfven eigenmode (TAE) driven unstable by energetic ions in the Tokamak Fusion Test Reactor (TFTR) [Phys. Plasmas 1, 1560 (1994)] is studied. The evolution of instabilities can take on several scenarios: a single mode or several modes can be driven unstable at the same time, the spectrum can be steady or pulsating, and there can be negligible or anomalous loss associated with the instability. This paper presents a comparison between experimental results and recently developed nonlinear theory. Many features observed in experiment are compatible with the consequences of the nonlinear theory. Examples include the structure of the saturated pulse that emerges from the onset of instability of a single mode, and the decrease, but persistence, of TAE signals when the applied rf power is reduced or shut off. (C) 1997 American Institute of Physics. C1 UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712. RP Wong, KL (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 26 TC 26 Z9 26 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 393 EP 404 DI 10.1063/1.872098 PG 12 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900017 ER PT J AU Labaune, C Baldis, HA Renard, N Schifano, E Michard, A AF Labaune, C Baldis, HA Renard, N Schifano, E Michard, A TI Interplay between ion acoustic waves and electron plasma waves associated with stimulated Brillouin and Raman scattering SO PHYSICS OF PLASMAS LA English DT Article ID LASER-PRODUCED PLASMA; RANDOM-PHASE PLATE; HOT-SPOTS; INSTABILITIES; COMPETITION; SUPPRESSION AB Direct evidence is presented of the temporal and spatial interplay between ion acoustic waves (IAWs) associated with stimulated Brillouin scattering (SBS) and electron plasma waves (EPWs) associated with stimulated Raman scattering (SRS) in conditions of interest to inertial confinement fusion (ICF). The two types of waves grow over a limited region in the front part of the plasma, but at different times. Inhibition of the EPWs by the IAWs has been observed in the early part of the laser pulse, and this inhibition can be strengthened by increasing the level of the IAWs. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,INST LASER & PLASMA SCI,LIVERMORE,CA 94550. RP Labaune, C (reprint author), ECOLE POLYTECH,CNRS,LAB UTILISAT LASERS INTENSES,F-91128 PALAISEAU,FRANCE. NR 27 TC 22 Z9 23 U1 1 U2 6 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 423 EP 427 DI 10.1063/1.872282 PG 5 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900020 ER PT J AU Shvets, G Fisch, NJ AF Shvets, G Fisch, NJ TI Electron-ion collisions in intensely illuminated plasmas SO PHYSICS OF PLASMAS LA English DT Article ID INVERSE-BREMSSTRAHLUNG; ABSORPTION RATE; FIELD AB In the presence of a high-frequency intense uniform electric field, the collisions of electrons with ions can be made more frequent or less frequent, depending on the polarization of the hf field, the direction and magnitude of particle velocity, and the ratio of the plasma Debye length to the size of the electron oscillation in the hf field. The stimulated bremsstrahlung emission is calculated for both circularly and linearly polarized fields. (C) 1997 American Institute of Physics. RP Shvets, G (reprint author), PRINCETON PLASMA PHYS LAB,FORRESTAL CTR,POB 451,T-149,PRINCETON,NJ 08543, USA. NR 13 TC 14 Z9 14 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 428 EP 436 DI 10.1063/1.872101 PG 9 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900021 ER PT J AU Rose, HA AF Rose, HA TI Saturation of stimulated Brillouin scatter by self-consistent flow profile modification in laser hot spots SO PHYSICS OF PLASMAS LA English DT Article ID RANDOM-PHASE PLATE; INDUCED SPATIAL INCOHERENCE; RAMAN-SCATTERING; LIGHT SCATTERING; PLASMAS; FILAMENTATION; INSTABILITY; LANGMUIR; FLUCTUATIONS; BACKSCATTER AB Scattering instabilities, such as stimulated Brillouin scatter (SBS) and stimulated Raman scatter (SRS), transfer momentum to the plasma which leads to flow inhomogeneities in laser hot spots that may significantly reduce the level of SBS. Simple estimates and simulations shown that the magnitude of flow fluctuation scan reach Mach numbers of order unity in a time scale of hundreds of picoseconds. (C) 1997 American Institute of Physics. RP Rose, HA (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 35 TC 32 Z9 32 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 437 EP 446 DI 10.1063/1.872102 PG 10 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900022 ER PT J AU Beg, FN Bell, AR Dangor, AE Danson, CN Fews, AP Glinsky, ME Hammel, BA Lee, P Norreys, PA Tatarakis, M AF Beg, FN Bell, AR Dangor, AE Danson, CN Fews, AP Glinsky, ME Hammel, BA Lee, P Norreys, PA Tatarakis, M TI A study of picosecond laser-solid interactions up to 10(19) W cm(-2) SO PHYSICS OF PLASMAS LA English DT Article ID PLASMA INTERACTIONS; HARMONIC-GENERATION; RESONANT ABSORPTION; OVERDENSE PLASMA; HOT-ELECTRONS; PULSES; INTENSITY; CONTRAST; TARGETS; SIMULATIONS AB The interaction of a 1053 nm picosecond laser pulse with a solid target has been studied for focused intensities of up to 10(19) W cm(-2). The maximum ion energy cutoff E(max) (which is related to the hot electron temperature) is in the range 1.0-12.0 MeV and is shown to scale as E(max) approximate to I-1/3. The hot electron temperatures were in the range 70-400 keV for intensities up to 5X10(18) W cm(-2) with an indication of a high absorption of laser energy. Measurements of x-ray/gamma-ray bremsstrahlung emission suggest the existence of at least two electron temperatures. Collimation of the plasma flow has been observed by optical probing techniques. (C) 1997 American Institute of Physics. C1 RUTHERFORD APPLETON LAB,CENT LASER FACIL,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV BRISTOL,HH WILLS PHYS LAB,BRISTOL BS8 1TL,AVON,ENGLAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Beg, FN (reprint author), UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,PRINCE CONSORT RD,LONDON SW7 2AZ,ENGLAND. RI Lee, Paul/A-8749-2008 OI Lee, Paul/0000-0002-6385-4420 NR 62 TC 453 Z9 470 U1 5 U2 29 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 447 EP 457 DI 10.1063/1.872103 PG 11 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900023 ER PT J AU Li, YL Pretzler, G Lu, PX Fill, EE Nilsen, J AF Li, YL Pretzler, G Lu, PX Fill, EE Nilsen, J TI Study of Ne- and Ni-like x-ray lasers using the prepulse technique SO PHYSICS OF PLASMAS LA English DT Article ID HIGH-GAIN; 3P-3S TRANSITIONS; XUV LASER; GERMANIUM; TARGET; IONS; NM; AMPLIFICATION; LINES; SELENIUM AB Recent studies of lasing in Ne- and Ni-like ions on the Asterix IV iodine laser [H. Baumhacker et al. Appl. Phys. B 61, 325 (1995)] using the prepulse technique are reviewed. Experimental evidence shows that beam refraction is the main factor for the lack of lasing in low-Z elements, as well as the J=0-1 vs J=2-1 anomaly in Ne-like ion lasers when there is no prepulse. It is shown that the role of the prepulse in enhancing the J=0-1 lasing line in Ne-like ion is to produce a larger and more homogeneous plasma. The measurement of lasing on the J=0-1, 3p-3s transition in Ne-like Mn, V, Sc, Ca, K, Cl, S, and Si using the prepulse technique is reviewed. Wavelengths of these lasers range from 22 to 87 nm with gain lengths between 7 and 12. The drive energy for S was scaled down to 20 J. The experiment demonstrating the 12 nm lasing on the J=0-1, 4d-4p transition in Ni-like Sn is also reviewed. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. SHANGHAI INST OPT & FINE MECH,SHANGHAI 201800,PEOPLES R CHINA. RP Li, YL (reprint author), MAX PLANCK INST QUANTUM OPT,D-85748 GARCHING,GERMANY. RI Lu, Peixiang/I-7414-2013 NR 89 TC 21 Z9 21 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 479 EP 489 DI 10.1063/1.872106 PG 11 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900027 ER PT J AU Mikaelian, KO AF Mikaelian, KO TI Finite Larmor radius stabilization of the Rayleigh-Taylor turbulent mixing width SO PHYSICS OF PLASMAS LA English DT Article ID NUMERICAL-SIMULATION; INSTABILITY AB A diffusion model for turbulent mix [C. Cherfils and K. O. Mikaelian, Phys. Fluids 8, 522 (1996)] is compared with recent two-dimensional magnetohydrodynamic simulations by Huba [Phys. Plasmas 3, 2523 (1996)]. The model accounts for density gradient stabilization and for finite Larmor radius stabilization, thus suppressing the Rayleigh-Taylor mixing width to below its classical value. The model, which has no free parameters, appears to be in good agreement with Huba's numerical simulations. (C) 1997 American Institute of Physics. RP Mikaelian, KO (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 16 TC 0 Z9 0 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 499 EP 500 DI 10.1063/1.872108 PG 2 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900031 ER PT J AU Sovinec, CR Prager, SC AF Sovinec, CR Prager, SC TI Magnetohydrodynamic simulations of direct current helicity injection for current drive in tokamaks - Response SO PHYSICS OF PLASMAS LA English DT Editorial Material ID FIELD C1 UNIV WISCONSIN, MADISON, WI 53706 USA. RP Sovinec, CR (reprint author), LOS ALAMOS NATL LAB, POB 1663, LOS ALAMOS, NM 87545 USA. NR 10 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 1070-664X J9 PHYS PLASMAS JI Phys. Plasmas PD FEB PY 1997 VL 4 IS 2 BP 503 EP 504 DI 10.1063/1.872119 PG 2 WC Physics, Fluids & Plasmas SC Physics GA WH429 UT WOS:A1997WH42900033 ER PT J AU Wang, XN AF Wang, XN TI A pQCD-based approach to parton production and equilibration in high-energy nuclear collisions SO PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS LA English DT Review DE pQCD model; parton production; heavy-ion collisions ID HEAVY-ION COLLISIONS; QUARK-GLUON-PLASMA; LUND MONTE-CARLO; PARTICLE MULTIPLICITY DISTRIBUTIONS; TRANSVERSE-MOMENTUM DISTRIBUTIONS; ANTIPROTON-PROTON COLLISIONS; INCLUSIVE CROSS-SECTION; STRONG ELECTRIC-FIELD; GEV CM ENERGY; S = 630 AB A pQCD-based model for parton production and equilibration in ultrarelativistic heavy-ion collisions is reviewed. The model combines pQCD processes including initial and final state radiations together with string phenomenology for nonperturbative soft processes. Nuclear effects on the initial parton production, such as multiple parton scattering and nuclear shadowing of parton distribution functions are considered. Comparisons with existing data are made and further tests of the model to constrain model parameters are proposed. With the obtained space-time history of the parton production, evolution of the minijet gas toward a fully equilibrated parton plasma is studied. Direct probes of the early parton dynamics, such as pre-equilibrium photon and dilepton production, open charm production, J/psi suppression and jet quenching are also reviewed. RP Wang, XN (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,MAILSTOP 70A-3307,BERKELEY,CA 94720, USA. OI Wang, Xin-Nian/0000-0002-9734-9967 NR 230 TC 260 Z9 264 U1 0 U2 0 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 FEB PY 1997 VL 280 IS 5-6 BP 287 EP 371 DI 10.1016/S0370-1573(96)00022-1 PG 85 WC Physics, Multidisciplinary SC Physics GA WL835 UT WOS:A1997WL83500001 ER PT J AU Berk, HL Fowler, TK Ryutov, DD AF Berk, HL Fowler, TK Ryutov, DD TI Mikhail S. Ioffe - Obituary SO PHYSICS TODAY LA English DT Item About an Individual C1 UNIV CALIF BERKELEY,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Berk, HL (reprint author), UNIV TEXAS,AUSTIN,TX 78712, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD FEB PY 1997 VL 50 IS 2 BP 87 EP 87 DI 10.1063/1.2806536 PG 1 WC Physics, Multidisciplinary SC Physics GA WG436 UT WOS:A1997WG43600026 ER PT J AU Granatstein, V Marshall, T Diament, P Efthtimion, P AF Granatstein, V Marshall, T Diament, P Efthtimion, P TI S. Perry Schlesinger - Obituary SO PHYSICS TODAY LA English DT Item About an Individual C1 COLUMBIA UNIV,NEW YORK,NY. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ. RP Granatstein, V (reprint author), UNIV MARYLAND,COLLEGE PK,MD 20742, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0031-9228 J9 PHYS TODAY JI Phys. Today PD FEB PY 1997 VL 50 IS 2 BP 88 EP 88 DI 10.1063/1.2806538 PG 1 WC Physics, Multidisciplinary SC Physics GA WG436 UT WOS:A1997WG43600027 ER PT J AU Vanlerberghe, GC Vanlerberghe, AE McIntosh, L AF Vanlerberghe, GC Vanlerberghe, AE McIntosh, L TI Molecular genetic evidence of the ability of alternative oxidase to support respiratory carbon metabolism SO PLANT PHYSIOLOGY LA English DT Article ID PLANT-MITOCHONDRIA; LEAF MITOCHONDRIA; TOBACCO; PROTEIN; PYRUVATE; ACTIVATION; PATHWAY; BIOLOGY; GROWTH; CELLS AB With the cytochrome pathway inhibited, AOX was able to support considerable growth of cultured tobacco (Nicotiana tabacum cv Petit Havana SR1) cells but the efficiency of carbon utilization decreased dramatically. Antisense cells with decreased AOX protein did not grow, whereas sense cells with elevated AOX protein had higher growth and respiration rates than the wild type. In antisense cells a large accumulation of pyruvate resulted in aerobic ethanolic fermentation. C1 MICHIGAN STATE UNIV, US DOE, PLANT RES LAB, E LANSING, MI 48824 USA. MICHIGAN STATE UNIV, DEPT BIOCHEM, E LANSING, MI 48824 USA. UNIV TORONTO, DIV LIFE SCI, SCARBOROUGH, ON M1C 1A4, CANADA. UNIV TORONTO, DEPT BOT, SCARBOROUGH, ON M1C 1A4, CANADA. NR 23 TC 51 Z9 52 U1 1 U2 3 PU AMER SOC PLANT BIOLOGISTS PI ROCKVILLE PA 15501 MONONA DRIVE, ROCKVILLE, MD 20855 USA SN 0032-0889 EI 1532-2548 J9 PLANT PHYSIOL JI Plant Physiol. PD FEB PY 1997 VL 113 IS 2 BP 657 EP 661 PG 5 WC Plant Sciences SC Plant Sciences GA WH572 UT WOS:A1997WH57200040 ER PT J AU Bonoli, PT Porkolab, M Ramos, JJ Nevins, W Kessel, C AF Bonoli, PT Porkolab, M Ramos, JJ Nevins, W Kessel, C TI Negative magnetic shear modes of operation in the Alcator C-Mod tokamak near the beta limit SO PLASMA PHYSICS AND CONTROLLED FUSION LA English DT Article ID HYBRID CURRENT DRIVE; ENHANCED CONFINEMENT; STABILITY; SIMULATION; EFFICIENCY; PLASMAS AB The stability properties of non-inductively driven, reversed-shear type current profiles that may be achieved for Alcator C-Mod tokamak-like parameters (aspect ratio R/a = 3) are examined. It is found that without a conducting wall, the best stability results (beta(N) up to 3.7) are achieved for highly triangular plasmas (delta = 0.7) at q(min) = 2.2, for relatively broad pressure profiles (p(0)/p(avg) = 2.8) and large values of r(min)/a (= 0.75). For elliptical or circular cross-sectional plasmas with little triangularity, the stability limits are significantly lower (beta(Nmax) = 2.2). Finally, more-peaked pressure profiles (p(0)/p(avg) = 4.5) have lower beta limits than broader profiles. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 95540. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Bonoli, PT (reprint author), MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139, USA. NR 25 TC 25 Z9 25 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0741-3335 J9 PLASMA PHYS CONTR F JI Plasma Phys. Control. Fusion PD FEB PY 1997 VL 39 IS 2 BP 223 EP 236 DI 10.1088/0741-3335/39/2/001 PG 14 WC Physics, Fluids & Plasmas SC Physics GA WM727 UT WOS:A1997WM72700001 ER PT J AU Lapenta, G Brackbill, JU AF Lapenta, G Brackbill, JU TI Simulation of dust particle dynamics for electrode design in plasma discharges SO PLASMA SOURCES SCIENCE & TECHNOLOGY LA English DT Article ID GLOW-DISCHARGES; RF DISCHARGES; MODEL; DC AB We have modelled dust dynamics in capacitively coupled, self-cleaning reactors with grooved electrodes. Our model includes plasma dynamics, gas drag, complex geometry, and dust motion. Our calculations show that dust is trapped in grooves as observed in experiments. We also have investigated the effect of groove shape on dust trapping and find that circular-cross-section grooves are more effective traps than the square-cross-section grooves considered previously. Finally, we include the results of calculations of particle trapping in the complex geometry of a realistic device. RP Lapenta, G (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. OI Lapenta, Giovanni/0000-0002-3123-4024 NR 22 TC 20 Z9 20 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0963-0252 J9 PLASMA SOURCES SCI T JI Plasma Sources Sci. Technol. PD FEB PY 1997 VL 6 IS 1 BP 61 EP 69 DI 10.1088/0963-0252/6/1/009 PG 9 WC Physics, Fluids & Plasmas SC Physics GA WN063 UT WOS:A1997WN06300008 ER PT J AU Krener, AJ AF Krener, AJ TI Reciprocal diffusions in flat space SO PROBABILITY THEORY AND RELATED FIELDS LA English DT Article ID EUCLIDEAN QUANTUM-MECHANICS AB We describe the theory of reciprocal diffusions in flat space. A reciprocal process is a Markov random field on a one dimensional parameter space. Every Markov process is reciprocal but not vice versa. We describe the first and second order mean differential characteristics of reciprocal diffusions. This includes a new definition of stochastic acceleration. We show that reciprocal diffusions satisfy stochastic differential equations of second order, Associated to a reciprocal diffusion is a sequence of conservation laws, the first two of which are the familiar continuity and Euler equations. There are two cases where these laws can be closed after the first two. They are the mutually exclusive subclasses of Markov and quantum diffusions. The latter corresponds to solutions of the Schrodinger equation and may be part of a stochastic description of quantum mechanics. RP Krener, AJ (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT MATH,DAVIS,CA 95616, USA. NR 23 TC 11 Z9 11 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-8051 J9 PROBAB THEORY REL JI Probab. Theory Relat. Field PD FEB PY 1997 VL 107 IS 2 BP 243 EP 281 DI 10.1007/s004400050085 PG 39 WC Statistics & Probability SC Mathematics GA WJ460 UT WOS:A1997WJ46000006 ER PT J AU Minier, LMG Behrens, R AF Minier, LMG Behrens, R TI Thermal decomposition mechanisms of bis(2-fluoro-2,2-dinitroethyl) formal (FEFO) and bis(2-fluoro-2,2-dinitroethyl) difluoroformal (DFF) from simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) measurements SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article AB The simultaneous thermogravimetric modulated beam mass spectrometry (STMBMS) technique has been applied to measure the vapor pressures and evaluate the thermal decomposition chemistry of two energetic liquids, bis(2-fluoro-2,2-dinitroethyl)formal (FEFO) and bis(2-fluro-2,2-dinetroethyl)difluoroformal (DFF). The resulting heat of vaporization (DeltaH(vnp)) and vapor pressure at 25 degreesC are 20.3 +/- 0.2 kcal/mol and 0.4 +/- 0.1 millitorr for FEFO, and 17.3 +/- 0.2 kcal/mol and 5.1 +/- 1.1 millitorr for DFF. The thermal decomposition of FEFO indicates there are six major pyrolysis pathways. The results suggest that FEFO initially decomposes at 150 degreesC by rearrangement of the nitro group (-NO2) to the nitrite group (-O-NO), followed by loss of NO. Some NO2 is also formed at 170 degreesC. Between 200 degreesC-300 degreesC, further pyrolysis occurs. In one pathway, the FEFO backbone remains intact and a high molecular-weight product is formed. The other three pathways involve scission of the FEFO backbone; one yielding CO2 (possible N2O), one yielding CH2O and one yielding C3H2NOF. Differences in the thermal decomposition behaviours in the liquid and gas phases are observed. In the thermal decomposition of DFF, the formal fluorine atoms stabilize the backbone structure. Numerous minor thermal decomposition products are also reported. C1 Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. RP Minier, LMG (reprint author), Sandia Natl Labs, Combust Res Facil, Livermore, CA 94551 USA. NR 17 TC 4 Z9 4 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD FEB PY 1997 VL 22 IS 1 BP 23 EP 33 DI 10.1002/prep.19970220107 PG 11 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA V2833 UT WOS:000168729000006 ER PT J AU Tang, PK AF Tang, PK TI PBX 9502 products equation of state SO PROPELLANTS EXPLOSIVES PYROTECHNICS LA English DT Article AB We constructed a Jones-Wilkins-Lee (JWL) equation of state (EOS) for the PBX 9502 detonation products based on a standard one by lowering the Chapman-Jouget (CJ) pressure. We found that a slow component exists in the chemical reaction rate, and the global hydrodynamic behavior as exhibited by the standard EOS reflects such an effect. by reducing the CJ pressure, we effectively remove the contribution of the slow reaction from the standard EOS, and the new EOS should represent the detonation products better. In conjunction with a reactive burn model which includes a slow component, the products EOS performs better than the standard EOS. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. RP Tang, PK (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret & Computat Phys Div, Los Alamos, NM 87545 USA. NR 14 TC 1 Z9 2 U1 0 U2 0 PU WILEY-V C H VERLAG GMBH PI BERLIN PA PO BOX 10 11 61, D-69451 BERLIN, GERMANY SN 0721-3115 J9 PROPELL EXPLOS PYROT JI Propellants Explos. Pyrotech. PD FEB PY 1997 VL 22 IS 1 BP 45 EP 50 DI 10.1002/prep.19970220110 PG 6 WC Chemistry, Applied; Engineering, Chemical SC Chemistry; Engineering GA V2833 UT WOS:000168729000009 ER PT J AU Lin, JYD MuhlmannDiaz, MC Stackhouse, MA Robinson, JF Taccioli, GE Chen, DJ Bedford, JS AF Lin, JYD MuhlmannDiaz, MC Stackhouse, MA Robinson, JF Taccioli, GE Chen, DJ Bedford, JS TI An ionizing radiation-sensitive CHO mutant cell line: irs-20 .4. Genetic complementation, V(D)J recombination and the scid phenotype SO RADIATION RESEARCH LA English DT Article ID HAMSTER OVARY CELLS; DNA-REPAIR; DEFECT; MUTATION; DEFICIENCY; SIGNAL; MOUSE; MICE AB The genetic defect responsible for hypersensitivity of Chinese hamster ovary (CHO) irs-20 cells to ionizing radiation was found to be recessive in nature and could be complemented to produce wild-type radiosensitivity in irs-20/human hybrids. The radiosensitivities of six hybrid clones were determined based on their colony-forming ability under continuous irradiation at 6 cGy/h, A parallel cytogenetic analysis revealed a concordance between the presence or absence of human chromosome 8 and the resistant or sensitive phenotype, Confirming evidence was obtained using human chromosome 8-specific PCR primers, Positive amplification was obtained in hybrids with wild-type radiosensitivity, while no amplification was obtained in sensitive hybrids, Complementation analysis between radiosensitive CHO irs-20 and murine scid cell lines was carried out to determine whether the defects leading to their ionizing radiation hypersensitivity could be corrected by genetic complementation in the hybrids. Complementation did not occur, A transient V(D)J recombination assay after the introduction of the RAG1 and RAG2 genes indicated that the V(D)J recombination ability of the CHO irs-20 cells was about 10% of that for the CHO wild-type cells for signal join formation with an 80% joining fidelity and only 3% of the parental level for coding join formation. These data show that murine scid and irs-2O mutant hamster cells fall into the same complementation group and show similar defects in V(D)J recombination. (C) 1997 by Radiation Research Society. C1 COLORADO STATE UNIV,DEPT RADIOL HLTH SCI,FT COLLINS,CO 80523. UNIV ALABAMA,DIV RADIAT BIOL,BIRMINGHAM,AL 35233. UNIV ALABAMA,GENE THERAPY PROGRAM,BIRMINGHAM,AL 35233. BOSTON UNIV,SCH MED,BOSTON,MA 02118. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NCI NIH HHS [CA09236, CA18023, CA49501] NR 29 TC 21 Z9 22 U1 0 U2 0 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD FEB PY 1997 VL 147 IS 2 BP 166 EP 171 DI 10.2307/3579417 PG 6 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA WE917 UT WOS:A1997WE91700007 PM 9008208 ER PT J AU Mitchell, TJ Ostrouchov, G Frome, EL Kerr, GD AF Mitchell, TJ Ostrouchov, G Frome, EL Kerr, GD TI A method for estimating occupational radiation dose to individuals, using weekly dosimetry data SO RADIATION RESEARCH LA English DT Article ID BAYESIAN DETECTION ANALYSIS; NUCLEAR INDUSTRY; CANCER MORTALITY; WORKERS; EXPOSURE AB Statistical analyses of data from epidemiological studies of workers exposed to radiation have been based on recorded annual radiation doses. It is usually assumed that the annual doses are known exactly, although it is generally recognized that the data contain uncertainty due to measurement error and bias. We propose the use of a probability distribution to describe an individual's dose during a specific period and develop statistical methods for estimating this distribution. The methods take into account the ''measurement error'' that is produced by the dosimetry system and the bias that was introduced by policies of recording doses below a threshold as zero. The method is applied to a sample of dose histories over the period 1945 to 1955 obtained from hard-copy dosimetry records at Oak Ridge National Laboratory (ORNL). The result of this evaluation raises serious questions about the validity of the historical personnel dosimetry data that are currently being used in studies of the effects of low doses in nuclear industry workers. In particular, it appears that there was a systematic underestimation of doses for ORNL workers. This may result in biased estimates of dose-response coefficients and their standard errors. (C) 1997 by Radiation Research Society. C1 OAK RIDGE NATL LAB,MATH SCI SECT,DIV MATH & COMP SCI,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,ASSESSMENT TECHNOL SECT,HLTH SCI RES DIV,OAK RIDGE,TN 37831. NR 27 TC 18 Z9 18 U1 0 U2 1 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD FEB PY 1997 VL 147 IS 2 BP 195 EP 207 DI 10.2307/3579421 PG 13 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA WE917 UT WOS:A1997WE91700011 PM 9008212 ER PT J AU Inskip, PD Hartshorne, MF Tekkel, M Rahu, M Veidebaum, T Auvinen, A Crooks, LA Littlefield, LG McFee, AF Salomaa, S Makinen, S Tucker, JD Sorensen, KJ Bigbee, WL Boice, JD AF Inskip, PD Hartshorne, MF Tekkel, M Rahu, M Veidebaum, T Auvinen, A Crooks, LA Littlefield, LG McFee, AF Salomaa, S Makinen, S Tucker, JD Sorensen, KJ Bigbee, WL Boice, JD TI Thyroid nodularity and cancer among Chernobyl cleanup workers from Estonia SO RADIATION RESEARCH LA English DT Article ID ATOMIC-BOMB SURVIVORS; GLYCOPHORIN-A LOCUS; SOMATIC-CELL MUTATIONS; CHROMOSOME-ABERRATIONS; IONIZING-RADIATION; FREQUENCY; CHILDHOOD; ACCIDENT; ERYTHROCYTES; LYMPHOCYTES AB Thyroid examinations, including palpation, ultrasound and, selectively, fine-needle aspiration biopsy, were conducted on nearly 2,000 Chernobyl cleanup workers from Estonia to evaluate the occurrence of thyroid cancer and nodular thyroid disease among men with protracted exposure to ionizing radiation. The examinations were conducted in four cities in Estonia during March-April 1995, 9 years after the reactor accident. The study population was selected from a predefined cohort of 4,833 cleanup workers from Estonia under surveillance for cancer incidence. These men had been sent to Chernobyl between 1986 and 1991 to entomb the damaged reactor, remove radioactive debris and perform related cleanup activities. A total of 2,997 men were invited for thyroid screening and 1,984 (66%) were examined. Estimates of radiation dose from external sources were obtained from military or other institutional records, and details about service dates and types of work performed while at Chernobyl were obtained from a self-administered questionnaire. Blood samples were collected for assay of chromosomal translocations in circulating lymphocytes and loss of expression of the glycophorin A (GPA) gene in erythrocytes. The primary outcome measure was the presence or absence of thyroid nodules as determined by the ultrasound examination. Of the screened workers, 1,247 (63%) were sent to Chernobyl in 1986, including 603 (30%) sent in April or May, soon after the accident. Workers served at Chernobyl for an average of 3 months. The average age was 32 years at the time of arrival at Chernobyl and 40 years at the time of thyroid examination. The mean documented radiation dose from external sources was 10.8 cGy. Biological indicators of exposure showed low correlations with documented dose, but did not indicate that the mean dose for the population was higher than the average documented dose. Ultrasound examinations revealed thyroid nodules in 201 individuals (10.2%). The prevalence of nodules increased with age at examination, but no significant associations were observed with recorded dose, date of first duty at Chernobyl, duration of service at Chernobyl, building the sarcophagus or working on the roof of neighboring buildings or close to the damaged reactor. Nodularity showed a nonsignificant (p((1)) = 0.10) positive association with the proportion of lymphocytes with chromosome translocations, but associations with the frequency of variant erythrocytes in the GPA assay were weak and unstable (p((1)) greater than or equal to 0.46). The majority of fine-needle biopsies taken on 77 study participants indicated benign nodular disease. However, two cases of papillary carcinoma and three benign follicular neoplasms were identified and referred for treatment. Both men with thyroid cancer had been sent to Chernobyl in May of 1986, when the potential for exposure to radioactive iodines was greatest. Chernobyl cleanup workers from Estonia did not experience a markedly increased risk of nodular thyroid disease associated with exposure to external radiation. Possible reasons for the apparent absence of effect include low radiation doses, the protracted nature of the exposure, errors in dose measurement, low sensitivity of the adult thyroid gland or the insufficient passage of time for a radiation effect to be expressed. (C) 1997 by Radiation Research Society. C1 NCI, RADIAT EPIDEMIOL BRANCH, EPIDEMIOL & BIOSTAT PROGRAM, DIV CANC EPIDEMIOL & GENET, BETHESDA, MD 20892 USA. UNIV NEW MEXICO, DEPT RADIOL, ALBUQUERQUE, NM 87131 USA. INST CLIN & EXPT MED, TALLINN, ESTONIA. FINNISH CANC REGISTRY, FIN-00170 HELSINKI, FINLAND. VET ADM MED CTR, DEPT PATHOL, ALBUQUERQUE, NM 87131 USA. OAK RIDGE INST SCI & EDUC, DIV MED SCI, OAK RIDGE, TN 37831 USA. FINNISH CTR RADIAT & NUCL SAFETY, HELSINKI, FINLAND. LAWRENCE LIVERMORE NATL LAB, BIOL & BIOTECHNOL RES PROGRAM, LIVERMORE, CA 94551 USA. UNIV PITTSBURGH, GRAD SCH PUBL HLTH, DEPT ENVIRONM & OCCUPAT HLTH, PITTSBURGH, PA 15238 USA. RI Rahu, Mati/A-9981-2008; OI Auvinen, Anssi/0000-0003-1125-4818 FU NCI NIH HHS [N01-CP-50520, N01-CP-85638-03, YO1-CP4-0599-01] NR 47 TC 46 Z9 47 U1 1 U2 8 PU RADIATION RESEARCH SOC PI LAWRENCE PA 810 E TENTH STREET, LAWRENCE, KS 66044 USA SN 0033-7587 EI 1938-5404 J9 RADIAT RES JI Radiat. Res. PD FEB PY 1997 VL 147 IS 2 BP 225 EP 235 DI 10.2307/3579424 PG 11 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA WE917 UT WOS:A1997WE91700014 PM 9008215 ER PT J AU Schieve, LA Davis, F Roeske, J Handler, A Freels, S Stinchcomb, T Keane, A AF Schieve, LA Davis, F Roeske, J Handler, A Freels, S Stinchcomb, T Keane, A TI Evaluation of internal alpha-particle radiation exposure and subsequent fertility among a cohort of women formerly employed in the radium dial industry SO RADIATION RESEARCH LA English DT Article ID LONG-TERM SURVIVORS; ATOMIC BOMBS; CHILDHOOD; RETENTION; LEUKEMIA AB This study examined the effect of internal exposure to alpha-particle radiation on subsequent fertility among women employed in the radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips, The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n = 603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of alpha particles emitted, fraction of energy absorbed within the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of gamma-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility. (C) 1997 by Radiation Research Society. C1 UNIV ILLINOIS,SCH PUBL HLTH,DIV EPIDEMIOL & BIOSTAT,CHICAGO,IL. UNIV CHICAGO,DEPT RADIAT & CELLULAR ONCOL,DIV BIOL SCI,CHICAGO,IL 60637. UNIV CHICAGO,PRITZKER SCH MED,CHICAGO,IL 60637. UNIV ILLINOIS,SCH PUBL HLTH,DIV COMMUNITY HLTH SCI,CHICAGO,IL. DEPAUL UNIV,DEPT PHYS,CHICAGO,IL 60604. ARGONNE NATL LAB,ENVIRONM SAFETY & HLTH DIV,ARGONNE,IL 60439. NR 42 TC 5 Z9 6 U1 1 U2 3 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD FEB PY 1997 VL 147 IS 2 BP 236 EP 244 DI 10.2307/3579425 PG 9 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA WE917 UT WOS:A1997WE91700015 PM 9008216 ER PT J AU Franko, AJ Sharplin, J Ghahary, A BarcellosHoff, MH AF Franko, AJ Sharplin, J Ghahary, A BarcellosHoff, MH TI Immunohistochemical localization of transforming growth factor beta and tumor necrosis factor alpha in the lungs of fibrosis-prone and ''non-fibrosing'' mice during the latent period and early phase after irradiation SO RADIATION RESEARCH LA English DT Article ID INDUCED PULMONARY FIBROSIS; STRAIN-DEPENDENT DIFFERENCES; RNA ENCODING PROCOLLAGENS; MOUSE LUNG; RADIATION-INJURY; GENE-EXPRESSION; BLEOMYCIN; CYTOKINES; INFLAMMATION; PNEUMONITIS AB To evaluate the possibility that TGF-beta and TNF-alpha are involved in fibrosis induced in mouse lung by irradiation, the proportion of cells immunoreactive for each was compared in two strains of mice. C3HeB/FeJ mice develop only classical pneumonitis during the early phase, whereas C57L/J mice develop small, tightly packed areas of inflammation which undergo fibrosis during the latent period, and exhibit progressive fibrosis of large regions of intense inflammation during the early phase. Very few cells were immunoreactive for an antibody to the latency-associated peptide (LAP) of TGF-beta during the latent period in C3HeB/FeJ mice, and no cells were positive during the early phase. In contrast, between 0.7 and 10% of cells were positive in C57L/J mice in lesions without fibrosis and in lesions in the early stages of fibrosis. Fibroblasts positive for LAP were seen only in lesions containing fibrosis. A similar pattern of immunoreactivity was seen in C57L/J mice using an antibody which recognizes active TGF-beta, with the exception that positive fibroblasts were observed within areas of inflammation without fibrosis. Thus the association of active TGF-beta with fibroblasts might be a characteristic of the initiation of fibrosis in this model. TNF-alpha was detected in macrophages in all classes of lesions, and minor differences between the strains did not appear to be biologically meaningful. (C) 1997 by Radiation Research Society. C1 UNIV ALBERTA,DEPT ONCOL,EDMONTON,AB,CANADA. UNIV ALBERTA,DEPT SURG,EDMONTON,AB,CANADA. UNIV CALIF BERKELEY,LAWRENCE BERKELY NATL LAB,DIV LIFE SCI,BERKELEY,CA 94720. RP Franko, AJ (reprint author), CROSS CANC INST,DEPT RADIOBIOL,EDMONTON,AB T6G 1Z2,CANADA. NR 40 TC 100 Z9 107 U1 0 U2 3 PU RADIATION RESEARCH SOC PI OAK BROOK PA 2021 SPRING RD, STE 600, OAK BROOK, IL 60521 SN 0033-7587 J9 RADIAT RES JI Radiat. Res. PD FEB PY 1997 VL 147 IS 2 BP 245 EP 256 DI 10.2307/3579426 PG 12 WC Biology; Biophysics; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Biophysics; Radiology, Nuclear Medicine & Medical Imaging GA WE917 UT WOS:A1997WE91700016 PM 9008217 ER PT J AU Bogen, KT Gold, LS AF Bogen, KT Gold, LS TI Trichloroethylene cancer risk: Simplified calculation of PBPK-based MCLs for cytotoxic end points SO REGULATORY TOXICOLOGY AND PHARMACOLOGY LA English DT Review ID REGIOISOMERIC MERCAPTURIC ACIDS; DRINKING-WATER CONTAMINATION; CONJUGATE BETA-LYASE; MALE B6C3F1 MOUSE; CELL-PROLIFERATION; SPECIES-DIFFERENCES; TRICHLOROACETIC-ACID; DICHLOROACETIC ACID; GLUTATHIONE CONJUGATION; HUMAN CARCINOGENESIS AB Cancer risk assessments for trichloroethylene (TCE) based on linear extrapolation from bioassay results are questionable in light of new data on TCE's likely mechanism of action involving induced cytotoxicity, for which a threshold-type dose-response model may be more appropriate. Previous studies have shown that if a genotoxic mechanism for TCE is assumed, algebraic methods can considerably simplify the use of physiologically based pharmacokinetic (PBPK) models to estimate virtually safe environmental concentrations for humans based on rodent cancer-bioassay data. We show here how such methods can be extended to the case in which TCE is assumed to induce cancer via cytotoxicity, to estimate environmentally safe concentrations based on rodent toxicity data. These methods can be substituted for the numerical methods typically used to calculate PBPK-effective doses when these are defined as peak concentrations. me selected liver and kidney as plausible target tissues, based on an analysis of rodent TCE-bioassay data and on a review of related data bearing on mechanism. Tumor patterns in rodent bioassays are shown to be consistent with our estimates of PBPK-based, effective cytotoxic doses to mice and rats used in these studies. When used with a margin of exposure of 1000, our method yielded maximum concentration levels for TCE of 16 ppb (87 mu g/m(3)) for TCE in air respired 24 hr/ day, 700 ppb (3.8 mg/m(3)) for TCE in air respired for relatively brief daily periods (e.g., 0.5 hr while showering/bathing), and 210 mu g/liter for TCE in drinking water assuming a daily 2-liter ingestion. Cytotoxic effective doses were also estimated for occupational respiratory exposures. These estimates indicate that the current OSHA permissible exposure limit for TCE would produce metabolite concentrations that exceed an acute no observed adverse effect level for hepatotoxicity in mice. On this basis, the OSHA TCE limit is not expected to be protective. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DIV BIOCHEM & MOL BIOL,BERKELEY,CA 94720. RP Bogen, KT (reprint author), LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV,L-396,7000 EAST AVE,LIVERMORE,CA 94550, USA. NR 119 TC 21 Z9 22 U1 1 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0273-2300 J9 REGUL TOXICOL PHARM JI Regul. Toxicol. Pharmacol. PD FEB PY 1997 VL 25 IS 1 BP 26 EP 42 DI 10.1006/rtph.1996.1070 PG 17 WC Medicine, Legal; Pharmacology & Pharmacy; Toxicology SC Legal Medicine; Pharmacology & Pharmacy; Toxicology GA WK540 UT WOS:A1997WK54000004 PM 9056499 ER PT J AU Herwig, LO AF Herwig, LO TI Impacts of global electrification based upon photovoltaic technologies SO RENEWABLE ENERGY LA English DT Article DE photovoltaic technology; photovoltaics; PV; global electrification; solar electric; enabling technology; renewable electric power AB The impacts of global electrification based upon photovoltaic technologies are examined and estimated from the following points of view: the number of photovoltaic systems in place, the power being delivered by them, the number of persons benefiting from the power being delivered, the total sales and economic benefits, and the number of jobs being created in manufacturing and installing them. Particular attention is given to estimated impacts on global electrification for rural (off-grid) populations in developing countries. The role of photovoltaic power technology as an enabling technology is discussed. Also, the growing impact of photovoltaic power technology as a competitive power technology for grid-connected needs is examined relative to its developing role as an alternative supplier of global electric power in competition with utility-generated power currently dominated by fossil- and nuclear-fueled electric generating plants. Finally, the positive impacts on the earth's environment as a result of generating electric power using photovoltaic technology are discussed relative to not producing carbon dioxide and other gases along with fuel wastes. Published by Elsevier Science Ltd. RP Herwig, LO (reprint author), US DOE,1000 INDEPENDENCE AVE SW,WASHINGTON,DC 20585, USA. NR 6 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 139 EP 143 DI 10.1016/0960-1481(96)00052-3 PG 5 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900005 ER PT J AU Ancona, DF Goldman, PR Thresher, RW AF Ancona, DF Goldman, PR Thresher, RW TI Wind program technological developments in the United States SO RENEWABLE ENERGY LA English DT Article AB Under its wind energy research and development program, the U.S. Department of Energy (DOE) works as a partner with industry to improve understanding of wind system technology and to develop and deploy advanced wind turbines in multi-regional markets. Installed capacity in the U.S. reached 1720 MW by the end of 1995. This figure however does not include some capacity that was retired or taken off line. Growth of about 140 MW during 1995, is attributed to improved and lower cost turbines and was stimulated in part by the availability of energy tax credits and production and financial incentives. In addition, there are nearly 500 MW of firm contracts for new domestic wind plants. Recently, there has been substantial growth outside the U.S. Europe went from 1671 MW in 1994 to 2478 MW in 1995 and the rest of the world went from 192 MW in 1994 to 642 MW in 1995. Commercial projects are currently producing electricity in the $0.05 to $0.07/kWh range operating at moderate (5.8 m/s average) wind sites. The U.S. DOE Wind Energy Systems Program is continuing broad based research and technology development, focusing on advanced wind turbine development. Contracts have been placed with industry for next generation design studies, innovative subsystems applied research, and value engineering to improve existing turbines. Some of these turbines are now being deployed in utility verification projects. Over the past year, the U.S. opened its National Wind Technology Center, located near Golden, Colorado. The center will include a new user facility to serve as a wind turbine blade and system testing and research center for industry. Copyright (C) 1996 Published by Elsevier Science Ltd. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. RP Ancona, DF (reprint author), US DOE,100 INDEPENDENCE AVE SW,WASHINGTON,DC 20585, USA. NR 0 TC 3 Z9 3 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 253 EP 258 DI 10.1016/0960-1481(96)00074-2 PG 6 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900027 ER PT J AU Tao, YX Scott, R Tu, P AF Tao, YX Scott, R Tu, P TI Phenomenological models for post-stall airfoil characteristics of horizontal-axis wind turbines SO RENEWABLE ENERGY LA English DT Article AB There exist significant differences in airfoil aerodynamic characteristics between wind tunnel test data (2-Dimensional flow) and field test data (3-D dimensional flow). Through the Combined Experiment Program (CEP), efforts have been made to investigate proper approaches to analyze such differences so that it enables us to incorporate the results into wind turbine rotor performance codes to assist in optimal design of a horizontal axis wind turbine. As a step towards a more in-depth, theoretical analysis of various physical effects under field conditions, we first analyze the difference in airfoil characteristics from phenomenological point of view by developing correlations from experimental data. The correlations for the difference in lift coefficient and drag coefficient between 2-dimensional and 3-dimensional flow are developed to form a basis and are suggested to be modified and included in the PROP code. Copyright (C) 1996 Published by Elsevier Science Ltd. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO. RP Tao, YX (reprint author), TENNESSEE STATE UNIV,DEPT MECH ENGN,NASHVILLE,TN 37203, USA. NR 3 TC 0 Z9 1 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 259 EP 263 DI 10.1016/0960-1481(96)00075-4 PG 5 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900028 ER PT J AU Robinson, MC Tu, P AF Robinson, MC Tu, P TI Applied wind energy research at the National Wind Technology Center SO RENEWABLE ENERGY LA English DT Article RP Robinson, MC (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, 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, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 265 EP 272 DI 10.1016/0960-1481(96)00076-6 PG 8 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900029 ER PT J AU Bailey, B Colucci, C AF Bailey, B Colucci, C TI Research and development on the utilization of alcohol fuels at the National Renewable Energy Laboratory SO RENEWABLE ENERGY LA English DT Article DE alternative transportation fuels; vehicles; alcohols; methanol; ethanol AB The U.S. Department of Energy's Alternative Fuels Utilization Program has been conducting research and development (R&D) on alcohol fuels since the 1970s. One of its objectives is to advance the technology and establish the ultimate performance capability of alcohol fuels in conventional engines. Early projects investigated the performance of low-level alcohol blends. The program expanded to encompass the benefits of mid-range blends and neat alcohol fuel applications. The current R&D program at the National Renewable Energy Laboratory concentrates on designing engines and emission control systems around the properties of neat alcohol fuels. This paper presents the current status of R&D efforts and prospects for future developments for optimizing the performance of alcohol-fueled vehicles. Copyright (C) 1996 Published by Elsevier Science Ltd. RP Bailey, B (reprint author), NATL RENEWABLE ENERGY LAB,ALTERNAT FUELS UTILIZAT PROGRAM,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 2 TC 4 Z9 4 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 273 EP 278 DI 10.1016/0960-1481(96)00077-8 PG 6 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900030 ER PT J AU Mielenz, JR AF Mielenz, JR TI Feasibility studies for biomass-to-ethanol production facilities in Florida and Hawaii SO RENEWABLE ENERGY LA English DT Article DE biomass; ethanol; alternative fuels; SSF; greenhouse gas; oxygenates AB The National Renewable Energy Laboratory's (NREL) process development unit has been operating since 1995 to test technology to convert lignocellulosic biomass to fuel ethanol. Following this type of testing, a pre-commercial scale engineering demonstration is likely to be needed to demonstrate this technology at or near proposed commercial plant sites. As a result, NREL began a program to help industrial partners complete a sound feasibility studies that include detailed siting plans. These studies examine biomass availability and cost projections, delineate site requirements, identify qualifying sites, examine environmental and community impacts, and provide financial evaluations and projections. Results from two of the completed studies on the big island of Hawaii, and in central Florida provide valuable insight for future potential biomass-to-ethanol commercializing organizations. Copyright (C) 1996 Published by Elsevier Science Ltd. RP Mielenz, JR (reprint author), NATL RENEWABLE ENERGY LAB,TECHNOL MANAGEMENT CTR,BIOFUELS PROGRAM,GOLDEN,CO 80401, USA. NR 7 TC 5 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 279 EP 284 DI 10.1016/0960-1481(96)00078-X PG 6 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900031 ER PT J AU McMillan, JD AF McMillan, JD TI Bioethanol production: Status and prospects SO RENEWABLE ENERGY LA English DT Article DE fermentation; ethanol; lignocellulosic biomass; processing options; production status ID ZYMOMONAS-MOBILIS; ETHANOL; FERMENTATION; BIOMASS; PRETREATMENT; CELLULOSE; XYLOSE AB Production of fuel ethanol from renewable lignocellulosic materials (''bioethanol'') has the potential to reduce burgeoning world dependence on petroleum while decreasing net emissions of carbon dioxide, the principal greenhouse gas. This paper reviews the benefits and status of bioethanol production technology, focusing mostly on recent developments in the United States of America The composition of representative lignocellulosic biomass species is presented and processing options under investigation are described. Discussion of current research directions highlights recent breakthroughs that significantly improve the prospects for commercialization. The pace of recent developments suggests that large-scale bioethanol production facilities will come on line in the United States within the next several years. Copyright (C) 1996 Published by Elsevier Science Ltd. RP McMillan, JD (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 56 TC 84 Z9 86 U1 2 U2 27 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 295 EP 302 DI 10.1016/0960-1481(96)00081-X PG 8 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900034 ER PT J AU Williams, G Bloyd, C AF Williams, G Bloyd, C TI Institutional solutions for renewable energy SO RENEWABLE ENERGY LA English DT Article AB Institutional issues play a critical, but often overlooked, role in the implementation of renewable energy systems. This paper briefly reviews the institutional arrangements involved in deploying renewable energy from both the sender and receiver perspectives, giving the institutional basis, principal characteristics, and pros and cons of each institution. It then offers several perspectives on the critical issues facing the deployment of renewable energy systems before offering a number potential institutional based solutions. Copyright (C) 1996 Published by Elsevier Science Ltd. RP Williams, G (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 4 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 309 EP 314 DI 10.1016/0960-1481(96)00083-3 PG 6 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900036 ER PT J AU Sheffield, J AF Sheffield, J TI The role of energy efficiency and renewable energies in the future world energy market SO RENEWABLE ENERGY LA English DT Article DE population; energy demand; energy efficiency; renewable energies AB The world population is rising rapidly, notably in the developing countries. Historical trends suggest that increased annual energy use per capita is a good surrogate for the standard of living factors which promote a decrease in population growth rate. If these trends continue, the stabilization of the world's population will require the increased use of all sources of energy as cheap oil and gas are depleted. The improved efficiency of energy use and renewable energy sources will be essential to stabilizing population, while providing a decent standard all over the world. Copyright (C) 1996 Published by Elsevier Science Ltd. RP Sheffield, J (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 7 TC 8 Z9 8 U1 3 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 315 EP 318 DI 10.1016/0960-1481(96)00084-5 PG 4 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900037 ER PT J AU Sayigh, A Kazmerski, L Norton, B Coombs, J Bourillon, C Mays, I Fridleitsson, IB Gillet, A McConnell, R Farhar, BC AF Sayigh, A Kazmerski, L Norton, B Coombs, J Bourillon, C Mays, I Fridleitsson, IB Gillet, A McConnell, R Farhar, BC TI World Renewable Energy Congress IV - 15-21 June 1996, Adam's Mark Hotel, Denver, Colorado, USA - Final report SO RENEWABLE ENERGY LA English DT Editorial Material C1 UNIV ULSTER,COLERAINE BT52 1SA,LONDONDERRY,NORTH IRELAND. CPL SCI LTD,NEWBURY,BERKS,ENGLAND. RP Sayigh, A (reprint author), NREL,GOLDEN,CO, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0960-1481 J9 RENEW ENERG JI Renew. Energy PD FEB-MAR PY 1997 VL 10 IS 2-3 BP 489 EP 501 PG 13 WC GREEN & SUSTAINABLE SCIENCE & TECHNOLOGY; Energy & Fuels SC Science & Technology - Other Topics; Energy & Fuels GA VU499 UT WOS:A1997VU49900061 ER PT J AU Liu, Y Cline, D BenZvi, I Wang, XJ Sheehan, J Batchelor, K Malone, R Issapour, M AF Liu, Y Cline, D BenZvi, I Wang, XJ Sheehan, J Batchelor, K Malone, R Issapour, M TI Modified feed-forward control system at the Accelerator Test Facility SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A modified feed-forward control system has been operated at the Brookhaven Accelerator Test Facility to control the phase and amplitude of two high power klystron rf systems used to power a photocathode rf gun and a traveling wave electron linac. The changes to the control algorithm include an improved handling of cross coupling between the amplitude and the phase channels, an improved calibration routine that allows for changes in the matrix elements due to the variable base-line and improved filtering. The modifications to the software include modularity, portability; and user-friendliness. Improvements to the hardware include a linearized phase and amplitude controller with de biasing for an improved dynamic range. The feed-forward system can handle nonlinear and noninstantaneous systems. With simultaneous regulation of two channels, the phase and the amplitude fluctuations over a time span of more than 3 mu S were reduced to less than +/- 0.2 degrees and +/- 0.2%, from the initial +/- 2.7 degrees and +/- 1.8%, respectively. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY AGR & TECH COLL FARMINGDALE,FARMINGDALE,NY 11735. RP Liu, Y (reprint author), UNIV CALIF LOS ANGELES,CTR ADV ACCELERATORS,LOS ANGELES,CA 90024, USA. NR 3 TC 1 Z9 1 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1137 EP 1141 DI 10.1063/1.1147875 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400004 ER PT J AU Carlstrom, TN Hsieh, CL Stockdale, R Nilson, DG Hill, DN AF Carlstrom, TN Hsieh, CL Stockdale, R Nilson, DG Hill, DN TI Initial operation of the divertor Thomson scattering diagnostic on DIII-D SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Thomson scattering measurements of n(e) and T-e in the divertor region of a Tokamak are reported. These data are used as input to boundary physics codes such as UEDGE and DEGAS and to benchmark the predictive capabilities of these codes. These measurements have also contributed to the characterization of tokamak disruptions. A Nd:YAG laser (20 Hz, 1 J, 15 ns, 1064 nm) is directed vertically through the lower divertor region of the DIII-D Tokamak. A custom, aspherical collection lens (f/6.8) images the laser beam from 1 to 21 cm above the target plates into eight spatial channels with 1.5 cm vertical and 0.3 cm radial resolution. Two-dimensional mapping of the divertor region is achieved by sweeping the divertor X-point location radially through the fixed laser beam location. Fiber optics carry the light to polychromators whose interference filters have been optimized for low T-e measurements. Silicon avalanche photodiodes measure both the scattered and plasma background light. Temperatures and densities are typically in the range of 5-200 eV and 1-10 x 10(19) m(-3), respectively. Low temperatures, T-e < 1 eV, and high densities, n(e) > 8 x 10(20) m(-3) have been observed in detached plasmas. Background light levels have not been a significant problem. Reduction of the laser stray light permits Rayleigh calibration. Because of access difficulties, no in-vessel vacuum alignment target could be used. Instead, an in situ laser alignment monitor provides alignment information for each laser pulse. Results are compared with Langmuir probe measurements where good agreement is found except for regions of high n(e) and low T-e as measured by Thomson scattering. (C) 1997 American Insitute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA. RP Carlstrom, TN (reprint author), GEN ATOM CO,SAN DIEGO,CA 92186, USA. NR 13 TC 37 Z9 38 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1195 EP 1200 DI 10.1063/1.1147893 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400013 ER PT J AU Lo, E Nazikian, R Stutman, D Choe, W Kaita, R AF Lo, E Nazikian, R Stutman, D Choe, W Kaita, R TI Calibration and test of the tangential phase contrast imaging diagnostic on CDX-U SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID SYSTEM AB A novel CO, laser-based tangential imaging diagnostic was completely calibrated and the system was tested on CDX-U plasmas. It was shown that localized, two-dimensional images of the plasma electron density fluctuations in the tokamak core can be obtained from a tangential imaging beam [E. Lo, J. Wright, and R. Nazikian, Rev. Sci. Instrum. 66, 1180 (1995)]. A variation of the Zernike phase mirror is used. Test measurements made on sound waves verify that the system will image phase variations placed at the object plane. An absolute sensitivity of approximate to 1 x 10(7) cm(-3)/root Hz was determined. A series of plasma measurements made on CDX-U is described. Results show that the plasma fluctuations are two to three orders of magnitude above the noise floor of the diagnostic. It is also verified that a high-pass cut-off wave number (from approximate to 1 to 8 cm(-1)) for the fluctuations can be selected by translating the phase mirror. The density fluctuation k spectrum is measured and found to peak at approximate to 1-3 cm(-1). (C) 1997 American Institute of Physics. RP Lo, E (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Choe, Wonho/C-1556-2011; Stutman, Dan/P-4048-2015 NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1206 EP 1216 DI 10.1063/1.1147883 PG 11 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400015 ER PT J AU Cohen, BI Kaiser, TB Garrison, JC AF Cohen, BI Kaiser, TB Garrison, JC TI One- and two-dimensional simulations of ultra-short-pulse reflectometry SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID DENSITY PROFILE MEASUREMENTS; MICROWAVE REFLECTOMETRY; DIII-D; FLUCTUATIONS; SENSITIVITY; TOKAMAKS; PLASMAS; JET AB Ultra-short-pulse reflectometry is studied by means of the numerical integration of one- and two-dimensional full-wave equations for ordinary and extraordinary modes propagating in a plasma. The numerical calculations illustrate the use of the reflection of ultra-short-pulse microwaves as an effective probe of the density or magnetic profile in the presence of density or magnetic fluctuations in the plasma. Bragg resonance effects can be identified in the reflected signals, which give information on fluctuations. It is also demonstrated that ultra-short-pulse reflectometry can be used to perform correlation reflectometry measurements in which correlation lengths for density fluctuations are deduced from the observed cross-correlation function of phase shifts as a function of frequency. (C) 1997 American Institute of Physics. RP Cohen, BI (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 28 TC 15 Z9 15 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1238 EP 1243 DI 10.1063/1.1147896 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400019 ER PT J AU Allen, SL AF Allen, SL TI Recent results from tokamak divertor plasma measurements SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID H-MODE DISCHARGES; DIII-D TOKAMAK; ASDEX UPGRADE; TRANSPORT; REDUCTION; BOUNDARY AB New diagnostics have been developed to address key divertor physics questions, including: target plate heat flux reduction by radiation, basic edge transport issues, and plasma wall interactions (PWIs) such as erosion. A system of diagnostics measures the target plate heat flux (imaging ir thermography) and particle flux (probes, pressure and Penning gauges, and visible emission arrays). Recently, T-e, n(e), and P-e (electron pressure) have been measured in two-dimensions (2D) with divertor Thomson Scattering. During radiative divertor operation T-e is less than 2 eV, indicating that new atomic processes are important. Langmuir probes measure higher T-e in some cases. In addition, the measured P-e near the separatrix at the target plate is lower than the midplane pressure, implying radial momentum transport. Bolometer arrays, inverted with reconstruction algorithms, provide the two-dimensional core and divertor radiation profiles. Spectroscopic measurements identify the radiating species and provide information on impurity transport; both absolute chordal measurements and tomographic reconstructions of images are used. Either intrinsic carbon or an inert species (e.g., injected Ne) are usually observed, and absolute particle inventories are obtained. Computer codes are both benchmarked with the experimental data and provide important consistency checks. Several techniques are used to measure fundamental plasma transport and fluctuations, including probes and reflectometry. PWI issues are studied with in situ coupons and insertable samples (DiMES). Representative divertor results from DIII-D with references to results on other tokamaks will be presented. (C) 1997 American Institute of Physics. RP Allen, SL (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 40 TC 2 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1261 EP 1267 DI 10.1063/1.1147897 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400023 ER PT J AU Bitter, M Johnson, LC Ku, LP Roquemore, AL vonGoeler, S AF Bitter, M Johnson, LC Ku, LP Roquemore, AL vonGoeler, S TI Distinction between DD and DT neutrons in the TFTR neutron collimator SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A difficult part of the analysis of the neutron collimator data is the distinction between contributions from DD and DT neutrons. This is important for the majority of TFTR discharges, which use neutral deuterium heating beams and relatively small amounts of tritium. At present, the DT-neutron contribution is determined from a comparison of the chord-integrated neutron collimator data with measurements of the DT-neutron source strength from general wide-angle detectors, using an iterative computational method. A more satisfactory solution should be obtained with detectors that measure the contributions from DD and DT neutrons, and gamma radiation, directly. Purse-shaping techniques are insufficient, since the detectors in the neutron collimator are operated in current mode. The presently used data analysis is described and the concept of a new multilayered plastic detector that makes use of the differences in the attenuation of the various radiation components is presented. The dimensions of the detector are based on calculations of the attenuation for the expected neutron energy spectrum. (C) 1997 American Institute of Physics. RP Bitter, M (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 11 TC 2 Z9 2 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1268 EP 1272 DI 10.1063/1.1147898 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400024 ER PT J AU Bell, RE AF Bell, RE TI An inversion technique to obtain full poloidal velocity profiles in a tokamak plasma SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID DIII-D TOKAMAK; ALPHA-CHERS; ROTATION; TFTR; FIELD; SHEAR; MODE AB An inversion technique has been developed to calculate local poloidal rotation velocities of impurity ions from line-integrated measurements of an extended emission source in a tokamak plasma. This technique can recover radial spatial resolution that id lost due to the curvature of the held lines. With charge exchange emission from neutral beams, it can be used to obtain poloidal velocity profiles across the entire minor radius of the plasma without requiring restricted neutral beam height to localize the emission. The technique consists of two Abel-like matrix inversions to obtain the emissivity and the velocity-weighted emissivity from which the velocity is obtained. Use of the neutral beams breaks the assumed symmetry, but knowledge of the beam deposition and geometry allow analogous matrices to be generated. The inversion technique is demonstrated with a simulation of a poloidal rotation diagnostic for the TFTR tokamak with tangential neutral beams with a height of 80 cm. Two opposing vertical views are required to handle effects of the charge exchange cross section, which can cause apparent velocities greatly in excess of expected poloidal velocities. The simulated errors due to the inversion process are about 1.5 km/s near the plasma center. (C) 1997 American Institute of Physics. RP Bell, RE (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 21 TC 33 Z9 33 U1 0 U2 9 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1273 EP 1280 DI 10.1063/1.1147885 PG 8 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400025 ER PT J AU Swenson, CA AF Swenson, CA TI Linear thermal expansivity (1.5-300 K) and heat capacity (1.2-90 K) of Stycast 2850FT SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID EPOXY-RESIN; SOLIDS AB Linear thermal expansivities, alpha, have been obtained from 1 to 300 K for a sample of Stycast 2850FT epoxy that initially was cured at room temperature (X1), and then at 95 degrees C (X2). Heat capacities, C-p, were measured from 1 to 95 K for X2. The alpha's for X1 and X2 are roughly equal to and twice that of copper near room temperature, but differ by as much as 10% at low temperature. The alpha's approach those for copper near 100 K, but have a much smaller temperature dependence at lower temperatures. The different shapes of the alpha(T) and C-p(T) relations give a Gruneisen parameter, Gamma, which decreases from 1.2 at 10 K to 0.5 at 95 K. Both alpha and C-p show apparent changes in lattice properties near 4.5 K, and a low temperature anomaly (Gamma = 3.5) that is characteristic of amorphous solids. Sample relaxation (shortening) effects from 300 K to 110 K were more serious for X2 than for X1. Because of differences related to the curing procedure? these data should be used only semiquantitatively in the design of experiments in which Stycast 2850FT will be used as a construction material. Possible Stycast-related problems with a capacitance dilatometer are discussed. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Swenson, CA (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. NR 11 TC 17 Z9 17 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1997 VL 68 IS 2 BP 1312 EP 1315 DI 10.1063/1.1148064 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WJ314 UT WOS:A1997WJ31400033 ER PT J AU Toon, OB Zahnle, K Morrison, D Turco, RP Covey, C AF Toon, OB Zahnle, K Morrison, D Turco, RP Covey, C TI Environmental perturbations caused by the impacts of asteroids and comets SO REVIEWS OF GEOPHYSICS LA English DT Review ID CRETACEOUS-TERTIARY BOUNDARY; TUNGUSKA METEOR FALL; K-T BOUNDARY; NUCLEAR WINTER; EARTHS ATMOSPHERE; CHICXULUB CRATER; SHOCKED QUARTZ; K/T BOUNDARY; ACID-RAIN; SHOEMAKER-LEVY-9 AB We review the major impact-associated mechanisms proposed to cause extinctions at the Cretaceous-Tertiary geological boundary. We then discuss how the proposed extinction mechanisms may relate to the environmental consequences of asteroid and comet impacts in general. Our chief goal is to provide relatively simple prescriptions for evaluating the importance of impacting objects over a range of energies and compositions, but we also stress that there are many uncertainties. We conclude that impacts with energies less than about 10 Mt are a negligible hazard. For impacts with energies above 10 Mt and below about 10(4) Mt (i.e., impact frequencies less than one in 6 x 10(4) years, corresponding to comets and asteroids with diameters smaller than about 400 m and 650 m, respectively), blast damage, earthquakes, and fires should be important on a scale of 10(4) or 10(5) km(2), which corresponds to the area damaged in many natural disasters of recent history. However, tsunami excited by marine impacts could be more damaging, flooding a kilometer of coastal plain over entire ocean basins. In the energy range of 10(4)-10(5) Mt (intervals up to 3 x 10(5) years, corresponding to comets and asteroids with diameters up to 850 m and 1.4 km, respectively) water vapor injections and ozone loss become significant on the global scale. In our nominal model, such an impact does not inject enough submicrometer dust into the stratosphere to produce major adverse effects, but if a higher fraction of pulverized rock than we think likely reaches the stratosphere, stratospheric dust (causing global cooling) would also be important in this energy range. Thus 10(5) Mt is a lower limit where damage might occur beyond the experience of human history. The energy range from 10(5) to 10(6) Mt (intervals up to 2 x 10(6) years, corresponding to comets and asteroids up to 1.8 and 3 km diameter) is transitional between regional and global effects. Stratospheric dust, sulfates released from within impacting asteroids, and soot from extensive wildfires sparked by thermal radiation from the impact can produce climatologically significant global optical depths of the order of 10. Moreover, the ejecta plumes of these impacts may produce enough NO from shock-heated air to destroy the ozone shield. Between 10(6) and 10(7) Mt (intervals up to 1.5 x 10(7) years, corresponding to comets and asteroids up to 4 and 6.5 km diameter), dust and sulfate levels would be high enough to reduce light levels below those necessary for photosynthesis. Ballistic ejecta reentering the atmosphere as shooting stars would set fires over regions exceeding 10(7) km(2), and the resulting smoke would reduce light levels even further. At energies above 10(7) Mt, blast and earthquake damage reach the regional scale (10(6) km(2)). Tsunami cresting to 100 m and flooding 20 km inland could sweep the coastal zones of one of the world's ocean basins. Fires would be set globally. Light levels may drop so low from the smoke, dust, and sulfate as to make vision impossible. At energies approaching 10(9) Mt (>10(8) years) the ocean surface waters may be acidified globally by sulfur from the interiors of comets and asteroids. The Cretaceous-Tertiary impact in particular struck evaporate substrates that very likely generated a dense, widespread sulfate aerosol layer with consequent climatic effects. The combination of all of these physical effects would surely represent a devastating stress on the global biosphere. C1 NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. LAWRENCE LIVERMORE NATL LAB,ENVIRONM PROGRAMS,LIVERMORE,CA 94550. UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90095. NR 116 TC 223 Z9 233 U1 8 U2 99 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD FEB PY 1997 VL 35 IS 1 BP 41 EP 78 DI 10.1029/96RG03038 PG 38 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WJ454 UT WOS:A1997WJ45400003 ER PT J AU Rechard, RP Tierney, MS Sanchez, LC Martell, MA AF Rechard, RP Tierney, MS Sanchez, LC Martell, MA TI Bounding estimates for critical events when directly disposing highly enriched spent nuclear fuel in unsaturated tuff SO RISK ANALYSIS LA English DT Article DE criticality; nuclear waste repository; highly enriched spent nuclear fuel; risk assessment; performance assessment ID REACTORS; URANIUM; OKLO AB This paper examines the possibility of criticality in a nuclear waste repository. The estimated probabilities are rough bounds and do not entirely dismiss the possibility of a critical condition; however, they do point to the difficulty of creating conditions under which a critical mass could be assembled (i.e., corrosion of containers, separation of neutron absorbers from the fissile material, and collapse or precipitation of the fissile material). In addition, should a criticality occur in or near a container, the bounding consequence calculations showed that fissions from one critical event are quite small (< similar to 10(20) fissions, if similar to aqueous and metal accidents and experiments). Furthermore, a reasonable upper bound of total critical events of 10(28) fissions corresponds to only 0.1% of the number of fissions represented by the spent nuclear fuel inventory in a repository containing 70,000 metric tons of heavy metal (MTHM) (the expected size for the proposed repository at Yucca Mountain, Nevada). RP Rechard, RP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 42 TC 8 Z9 8 U1 0 U2 1 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD FEB PY 1997 VL 17 IS 1 BP 19 EP 35 DI 10.1111/j.1539-6924.1997.tb00840.x PG 17 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA WV857 UT WOS:A1997WV85700004 ER PT J AU Galambos, JD Holmes, JA AF Galambos, JD Holmes, JA TI Efficient treatment of uncertainty in numerical optimization SO RISK ANALYSIS LA English DT Article DE risk analysis; uncertainty; optimization; process modeling ID DESIGN AB We have combined the methods probabilistic risk analysis and optimization to devise a technique suitable for the efficient treatment of uncertainties (or the effects of random fluctuations) in the design and analysis of mathematically describable processes. The key step is the approximation, by a multivariable Taylor series expansion, of the influence of random variables on the objective function. Statistical averaging of this expansion leads to a description of the objective function in terms of the moments of the random variables. Knowledge or estimation of these moments allows the optimization to be carried out using standard calculus based techniques. An example is treated with three variations to illustrate the use of this technique for nonlinear sets of equations and objective functions. The method presented here is applicable to process models in manufacturing, systems analysis, and risk analysis. RP Galambos, JD (reprint author), OAK RIDGE NATL LAB,COMPUTAT PHYS & ENGN DIV,POB 2008,OAK RIDGE,TN 37831, USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD FEB PY 1997 VL 17 IS 1 BP 93 EP 96 DI 10.1111/j.1539-6924.1997.tb00847.x PG 4 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA WV857 UT WOS:A1997WV85700011 ER PT J AU Hsiung, LM Nieh, TG AF Hsiung, LM Nieh, TG TI Substructure in a creep deformed lamellar Tial alloy SO SCRIPTA MATERIALIA LA English DT Article RP Hsiung, LM (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT MAT SCI,POB 808,L-370,LIVERMORE,CA 94551, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 7 TC 20 Z9 20 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD FEB 1 PY 1997 VL 36 IS 3 BP 323 EP 330 DI 10.1016/S1359-6462(96)00380-6 PG 8 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WE339 UT WOS:A1997WE33900010 ER PT J AU Lai, W Munir, ZA McCoy, BJ Risbud, SH AF Lai, W Munir, ZA McCoy, BJ Risbud, SH TI Centrifugally-assisted combustion synthesis of functionally-graded materials SO SCRIPTA MATERIALIA LA English DT Article RP Lai, W (reprint author), UNIV CALIF LAWRENCE LIVERMORE NATL LAB,DEPT CHEM ENGN & MAT SCI,DIV MAT SCI & ENGN,DAVIS,CA 95616, USA. NR 6 TC 16 Z9 17 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD FEB 1 PY 1997 VL 36 IS 3 BP 331 EP 334 DI 10.1016/S1359-6462(96)00391-0 PG 4 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WE339 UT WOS:A1997WE33900011 ER PT J AU Harris, MK Thayer, PA Amidon, MB AF Harris, MK Thayer, PA Amidon, MB TI Sedimentology and depositional environments of middle Eocene terrigenous-carbonate strata, southeastern Atlantic Coastal Plain, USA SO SEDIMENTARY GEOLOGY LA English DT Article DE sedimentology; coastal plain; terrigenous-carbonate; middle Eocene; South Carolina ID SEA AB Basin-margin sediments of middle Eocene age in the Savannah River Site area consist of five terrigenous-carbonate lithofacies: quartz sand; calcareous quartz sand; sandy carbonate; muddy carbonate; and a transitional lithofacies that ranges from sandy, muddy carbonate to calcareous mud. The middle Eocene sediment package, which includes calcareous parts of the upper Congaree, Warley Hill, and Santee Formations, dips southeast at 4.7 m/km and thickens from 2 m at its updip edge to 95 m downdip. The presence of glauconite and a diverse faunal assemblage in all lithofacies suggests deposition in clear, well-oxygenated, open-marine waters of normal salinity on the inner to middle shelf with periods of marginal marine, nearshore, and deltaic influence. Coarse-grained terrigenous sand and calcareous sand, deposited in higher-energy, nearshore environments, occur near the updip limit. Fine-grained terrigenous mud, calcareous mud, and sandy and muddy carbonate are located downdip and accumulated in quieter water conditions on the inner and middle shelf. The transition from terrigenous to carbonate sediment occurs near the updip limit in a narrow zone less than 5 km wide. Three depositional sequences, which contain transgressive and highstand system tracts, are recognized within the middle Eocene calcareous interval. One is assigned to the upper Congaree Formation (TA3.1/3.2 cycles), one to the Warley Hill Formation (TA3.4 cycle), and one to the Santee Formation (TA3.5/3.6 cycles). The main control on areal distribution of facies was depositional environment, which was controlled primarily by sea-level eustasy and the amount, rate and locus of terrigenous influx. In updip areas, however, sediment distribution and thickness were also influenced by middle Eocene growth faulting. Diagenetic pathways vary with facies type, but generally include: (1) marine phreatic - boring of skeletal fragments by algae and fungi, grain micritization, and radially fibrous cementation; and (2) freshwater phreatic - inversion of high-Mg calcite to low-Mg calcite, dissolution of aragonitic allochems, formation of moldic porosity, precipitation of syntaxial calcite overgrowths on echinoderms, formation of calcite spar and isopachous calcite cement, neomorphism of micrite to microspar and pseudospar, precipitation of opal-CT lepispheres, replacement of mollusk shells by chalcedony, and precipitation of zeolites within secondary moldic pores. Quartz-rich facies have high interparticle porosity and excellent permeability. Mud-rich facies have low to moderate porosity and permeability owing to the isolation of moldic and vug pores. C1 UNIV N CAROLINA,DEPT EARTH SCI,WILMINGTON,NC 28403. WESTINGHOUSE SAVANNAH RIVER CO,SITE GEOTECH SERV,AIKEN,SC 29808. RP Harris, MK (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,POB 616,AIKEN,SC 29808, USA. NR 69 TC 10 Z9 10 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0037-0738 J9 SEDIMENT GEOL JI Sediment. Geol. PD FEB PY 1997 VL 108 IS 1-4 BP 141 EP 161 DI 10.1016/S0037-0738(96)00051-6 PG 21 WC Geology SC Geology GA WJ711 UT WOS:A1997WJ71100007 ER PT J AU Verbitskaya, EM Eremin, VK Ivanov, AM Li, Z Schmidt, B AF Verbitskaya, EM Eremin, VK Ivanov, AM Li, Z Schmidt, B TI Formation of radiation defects in high-resistivity silicon as a result of cyclic irradiation and annealing SO SEMICONDUCTORS LA English DT Article ID CHARGES N-EFF; DETECTORS AB Transformation of radiation-induced defects in p(+)-n-n(+) structures fabricated from high-resistivity n-type silicon subjected to cyclic irradiation and annealing is investigated. The kinetic behavior of the increase in the concentration of the C-i-O-i defects is analyzed as a function of the detector fabrication process. During the second irradiation cycle a transformation of the defects, which were formed as a result of annealing of the original radiation defects, is observed. The appearance of ''hidden'' sources of deep center formation is revealed. It is established that the presence of a higher oxygen concentration, which arises in the samples as a result of the extended silicon oxidation process, results in a more active complex-formation of carbon-containing defects in comparison with samples with reduced oxygen content. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. ROSSENDORF INC,RES CTR,INST PHYS ION BEAMS & MAT SCI,D-01314 DRESDEN,GERMANY. RP Verbitskaya, EM (reprint author), AF IOFFE PHYS TECH INST,POLITEKHNICHESKAYA 26,ST PETERSBURG 194021,RUSSIA. RI Verbitskaya, Elena/D-1521-2014; Ivanov, Alexander/E-3993-2014 NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 1063-7826 J9 SEMICONDUCTORS+ JI Semiconductors PD FEB PY 1997 VL 31 IS 2 BP 189 EP 193 DI 10.1134/1.1187105 PG 5 WC Physics, Condensed Matter SC Physics GA WL868 UT WOS:A1997WL86800021 ER PT J AU Chitanvis, SM AF Chitanvis, SM TI Revisiting shock waves in metals SO SHOCK WAVES LA English DT Article DE shock splitting; metals; strong shocks ID FLOW; SOLIDS AB We cast Wallace's theory of thermoplastic flow in conservative form. We point out the difference between our formulation, which accounts for contact with an external energy reservoir, and previous formulations of thermoplastic flow. The theory is exploited to show that the experiments of Johnson and Barker on 6062-T6 Al can be interpreted as a weak shock wave that splits into an infinite sequence of ''infinitesimal'' shocks, caused by increasing plasticity, leading to the observed smooth temporal velocity profile (a dispersed wave). We predict that overdriven shock waves in metals will split as well. We also re-examine the need for invoking a heat dissipation mechanism for overdriven shocks. It is briefly pointed out that our approach of casting the theory of thermoplastic flow in divergence form can be generalized easily to account for heat release in energetic solids. RP Chitanvis, SM (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 20 TC 0 Z9 0 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0938-1287 J9 SHOCK WAVES JI Shock Waves PD FEB PY 1997 VL 7 IS 1 BP 49 EP 54 DI 10.1007/s001930050062 PG 6 WC Mechanics SC Mechanics GA WU609 UT WOS:A1997WU60900007 ER PT J AU Kuperman, RG Carreiro, MM AF Kuperman, RG Carreiro, MM TI Soil heavy metal concentrations, microbial biomass and enzyme activities in a contaminated grassland ecosystem SO SOIL BIOLOGY & BIOCHEMISTRY LA English DT Article ID SUBSTRATE-INDUCED RESPIRATION; FLUORESCEIN DIACETATE; PLANT RESIDUES; CLAY-MINERALS; SEWAGE-SLUDGE; PINE FOREST; ACID-RAIN; COPPER; MICROORGANISMS; DECOMPOSITION AB Soil enzyme activities and microbial biomass were measured in a grassland ecosystem with a wide range of heavy metal concentrations ranging from 7.2 to 48.1 mmol kg(-1) (As, Cd, Cr, Cu, Ni, Pb and Zn) in portions of the U.S. Army's Aberdeen Proving Ground, Maryland, U.S.A. Total and fluorescein diacetate active (FDA) fungal biomass, FDA-active bacterial biomass, substrate-induced respiration (SIR), the activity of N-acetylglucosaminidase, beta-glucosidase, endocellulase, and acid and alkaline phosphatases were also measured. Most measures of microbial biomass were lower in polluted soils. Significant reductions (10- to 50-fold) in the activities of all enzymes closely paralleled the increase in heavy metal concentrations. These results demonstrate that heavy metal contamination of soil has adversely affected the abundance and activity of microorganisms involved in organic matter decomposition and nutrient cycling in this site. (C) 1997 Elsevier Science Ltd. C1 ARGONNE NATL LAB, ENVIRONM ASSESSMENT DIV, ARGONNE, IL 60439 USA. FORDHAM UNIV, LOUIS CALDER CTR, ARMONK, NY 10504 USA. RI Kuperman, Roman/D-4297-2009 NR 57 TC 148 Z9 177 U1 4 U2 47 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-0717 J9 SOIL BIOL BIOCHEM JI Soil Biol. Biochem. PD FEB PY 1997 VL 29 IS 2 BP 179 EP 190 DI 10.1016/S0038-0717(96)00297-0 PG 12 WC Soil Science SC Agriculture GA XC372 UT WOS:A1997XC37200009 ER PT J AU Tsuei, KD Johnson, PD AF Tsuei, KD Johnson, PD TI Charge transfer and a new image state of C-60 on Cu(111) surface studied by inverse photoemission SO SOLID STATE COMMUNICATIONS LA English DT Article DE fullerenes; surfaces and interfaces; electronic states ID SCANNING TUNNELING MICROSCOPY; RAY-ABSORPTION-SPECTROSCOPY; METAL-SURFACES; SOLID C-60; C60; ENERGY; C(60); MOLECULES; FILMS AB We have used inverse photoemission to study ultra-thin C-60 films adsorbed on Cu(111) surfaces. Unlike a previous study of C-60 adsorption on a Au film where the unoccupied states shift rigidly towards the Fermi level, the spectra here look strongly perturbed and more-like those characteristic of K3C60. This indicates that the interaction of C-60 With Cu is much stronger than with Au. Annealing at 350 degrees C results in a well ordered (4 x 4) structure as seen in LEED. An additional broad peak appears below the vacuum level. This new state has a parabolic dispersion with an effective mass dose to unity. We interpret this state as the image state or resonance on top of the metallized C-60 overlayer. Copyright (C) 1996 Elsevier Science Ltd C1 NATL TSING HUA UNIV,DEPT PHYS,HSINCHU 300,TAIWAN. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Tsuei, KD (reprint author), NATL TSING HUA UNIV,SYNCHROTRON RADIAT RES CTR,HSINCHU 300,TAIWAN. NR 25 TC 29 Z9 29 U1 1 U2 18 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1997 VL 101 IS 5 BP 337 EP 341 DI 10.1016/S0038-1098(96)00590-X PG 5 WC Physics, Condensed Matter SC Physics GA WB804 UT WOS:A1997WB80400008 ER PT J AU Shiloh, M Zhang, K Mogilevsky, R Hinks, DG AF Shiloh, M Zhang, K Mogilevsky, R Hinks, DG TI Seebeck coefficient of poly and single crystals of La-(2-x)Sr-(x)CuO4 SO SOLID STATE COMMUNICATIONS LA English DT Article ID THERMOELECTRIC-POWER; TRANSPORT-PROPERTIES; THERMOPOWER; LA1.85SR0.15CUO4; LA2-XSRXCUO4 AB Seebeck coefficient (S) of La-(2-x)Sr-(x)CuO4 was measured in the range x = 0 to x = 0.3. Data for single crystals show an increase in anisotropy with increase in x. The data for polycrystalline samples show good agreement with Heikes formula [1-3] and the values for x = 0.05 and x = 0.15 (underdoped), fits the expected values, obtained from (2/3S(ab) + 1/3S(c)), where S-ab is the in-plane and S-c is the c-axis Seebeck coefficient. For x = 0.2 and x = 0.25 (overdoped), the values for the polycrystals coincide with those of S-ab. The effect of oxygen vacancies, at ambient pressure, was detected only for x = 0.3 sample, for which S changed sign from positive, for oxygen deficient sample, to negative, for oxygen annealed sample. Copyright (C) 1996 Elsevier Science Ltd C1 UNIV CHICAGO,SCI & TECHNOL CTR SUPERCONDUCT,CHICAGO,IL 60637. UNIV CHICAGO,JAMES FRANCK INST,CHICAGO,IL 60637. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Shiloh, M (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 14 TC 1 Z9 1 U1 2 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1997 VL 101 IS 5 BP 389 EP 392 DI 10.1016/S0038-1098(96)00612-6 PG 4 WC Physics, Condensed Matter SC Physics GA WB804 UT WOS:A1997WB80400018 ER PT J AU Wolverton, C Zunger, A Schonfeld, B AF Wolverton, C Zunger, A Schonfeld, B TI Invertible and non-invertible alloy Ising problems SO SOLID STATE COMMUNICATIONS LA English DT Article DE disordered systems; order-disorder effects; thermodynamic properties ID SHORT-RANGE ORDER; ATOMIC INTERACTION; MONTE-CARLO; SCATTERING AB Physical properties of alloys are compared as computed from 'direct' and 'inverse' procedures. The direct procedure involves Monte Carlo simulations of a set of local density approximation (LDA)-derived pair and multibody interactions {v(f)}, generating short-range order (SRO), ground states, order-disorder transition temperatures, and structural energy differences. The inverse procedure involves 'inverting' the SRO generated from {v(j)} via inverse-Monte Carlo to obtain a set of pair only interactions {(v) over tilde(f)}. The physical properties generated from {(v) over tilde(f)} are then compared with those from {vf}. We find the following: (i) Inversion of the SRO is possible (even when {v(f)} contains multibody interactions but {(v) over tilde(f)} does not). (ii) Nevertheless, the resulting problem interactions {(v) over tilde(f)} agree with the input interactions {vf} only when the problem is dominated by pair interactions. Otherwise, {(v) over tilde(f)} are very different from {v(f)}. (iii) The same SRO pattern can be produced by drastically different sets {v(f)}. Thus, the effective interactions deduced from inverting SRO are not unique. (iv) Inverting SRO always misses configuration-independent (but composition-dependent) energies such as the volume deformation energy G(x); consequently, the ensuing {(v) over tilde(f)} cannot be used to describe formation enthalpies or two-phase regions of the phase diagram, which depend on G(x). (C) 1997 Elsevier Science Ltd C1 ETH ZURICH,INST ANGEW PHYS,CH-8093 ZURICH,SWITZERLAND. RP Wolverton, C (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Wolverton, Christopher/B-7542-2009; Zunger, Alex/A-6733-2013 NR 14 TC 19 Z9 19 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1997 VL 101 IS 7 BP 519 EP 523 DI 10.1016/S0038-1098(96)00626-6 PG 5 WC Physics, Condensed Matter SC Physics GA WF198 UT WOS:A1997WF19800009 ER PT J AU Pearton, SJ Shul, RJ McLane, GF Constantine, C AF Pearton, SJ Shul, RJ McLane, GF Constantine, C TI Reactive ion etching of III-V nitrides SO SOLID-STATE ELECTRONICS LA English DT Article; Proceedings Paper CT Topical Workshop on III-V Nitrides (TWN 95) CY SEP 21-23, 1995 CL CONGRESS CTR, NAGOYA, JAPAN SP AOARD, Japan Soc Appl Phys, IEEE EDS, IEEE LEOS HO CONGRESS CTR ID MOLECULAR-BEAM EPITAXY; GALLIUM NITRIDE; GAN; INN; PLASMAS; ALN; GROWTH; BCL3; AIN AB The chemical inertness and high bond strengths of the III-V nitrides lead to slower plasma etching rates than for more conventional III-V semiconductors under the same conditions. High ion density conditions (>3 x 10(11) cm(-3) ) such as those obtained in ECR or magnetron reactors produce etch rates up to an order of magnitude higher than for RIE, where the ion densities are in the 10(9)cm(-3) range. We have developed smooth anisotropic dry etches for GaN, InN, AIN and their alloy based on Cl-2/CH4/H-2/Ar, BCl3/Ar, Cl-2/H-2, Cl-2/SF6, HBr/H-2 and HI/H-2 plasma chemistries achieving etch rates up to similar to 4000 Angstrom/min at moderate d.c. bias voltages (less than or equal to -150 V). Ion-induced damage in the nitrides appears to be less apparent than in other III-Vs. One of the key remaining issues is the achievement of high selectivities for removal of one layer from another. (C) 1997 Elsevier Science Ltd. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. USA,RES LAB,FT MONMOUTH,NJ 07703. PLASMA THERM IP,ST PETERSBURG,FL 33716. RP Pearton, SJ (reprint author), UNIV FLORIDA,GAINESVILLE,FL 32611, USA. NR 19 TC 10 Z9 11 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD FEB PY 1997 VL 41 IS 2 BP 159 EP 163 DI 10.1016/S0038-1101(96)00158-X PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA WF763 UT WOS:A1997WF76300009 ER PT J AU Zavada, JM Abernathy, CR Pearton, SJ Mackenzie, JD Mileham, JR Wilson, RG Schwartz, RN HaggerottCrawford, M Shul, RJ Kilcoyne, SP Zhang, D Kolbas, RM AF Zavada, JM Abernathy, CR Pearton, SJ Mackenzie, JD Mileham, JR Wilson, RG Schwartz, RN HaggerottCrawford, M Shul, RJ Kilcoyne, SP Zhang, D Kolbas, RM TI Microdisk laser structures formed in III-V nitride epilayers SO SOLID-STATE ELECTRONICS LA English DT Article; Proceedings Paper CT Topical Workshop on III-V Nitrides (TWN 95) CY SEP 21-23, 1995 CL CONGRESS CTR, NAGOYA, JAPAN SP AOARD, Japan Soc Appl Phys, IEEE EDS, IEEE LEOS HO CONGRESS CTR AB Several kinds of nitride-based micro-resonators have been fabricated. Firstly, a microdisk laser structure comprising three InGaN/GaN quantum wells on a thick AIN buffer has been grown by metal-organic molecular beam epitaxy and fabricated using a combination of non-selective Cl-2/CH4/H-2/Ar dry etching and selective KOH-based wet etching of the AlN. These structures are of potential use in short wavelength photonic or optoelectronic circuits. In a second structure Er was implanted into a GaN layer to produce strong emission at 1.54 mu m. Similar results have been obtained in Er-implanted AIN, and AIN doped during epitaxial growth. (C) 1997 Published by Elsevier Science Ltd. C1 UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. N CAROLINA STATE UNIV,RALEIGH,NC 27695. RP Zavada, JM (reprint author), USA,RES OFF,RES TRIANGLE PK,NC 27709, USA. NR 7 TC 4 Z9 4 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD FEB PY 1997 VL 41 IS 2 BP 353 EP 357 DI 10.1016/S0038-1101(96)00244-4 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA WF763 UT WOS:A1997WF76300049 ER PT J AU Conroy, JFT BrucknerLea, C Janata, J AF Conroy, JFT BrucknerLea, C Janata, J TI Surface tension effects in tunneling microscopy SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT International Workshop on Electrochemistry: Solid vs Liquid State CY MAR 04-08, 1996 CL SCHLOSS RINGBERG, RINGBERG, GERMANY HO SCHLOSS RINGBERG DE tunneling microscopy; surface tension; Gibbs-Lippmann equation ID MERCURY SESSILE DROP AB The tip and the conducting substrate in tunneling microscopy form a capacitor. Similarly, in electrochemistry of polarized electrode the metal and the electrolyte form a double layer capacitor. It is shown that the energetics of these two capacitors, namely the surface tension of the substrate and of the polarized electrode, respectively, are governed by the same relationship, the Gibbs-Lippmann equation. The implications of this finding for STM imaging are discussed. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 19 TC 1 Z9 1 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 FEB PY 1997 VL 94 IS 1-4 BP 161 EP 164 DI 10.1016/S0167-2738(96)00504-8 PG 4 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WU966 UT WOS:A1997WU96600019 ER PT J AU Janata, J Josowicz, M AF Janata, J Josowicz, M TI Nernstian and non-nernstian potentiometry SO SOLID STATE IONICS LA English DT Article; Proceedings Paper CT International Workshop on Electrochemistry: Solid vs Liquid State CY MAR 04-08, 1996 CL SCHLOSS RINGBERG, RINGBERG, GERMANY HO SCHLOSS RINGBERG DE potentiometry; charge-transfer complexes; work function; Kelvin probe ID FIELD-EFFECT TRANSISTOR; HYDROGEN-CYANIDE; METHANOL VAPOR; WORK FUNCTION; POLYPYRROLE; LAYER AB It is possible to perform a potentiomeric measurement in the gas phase in such a way that the formation of charge transfer complex between the gaseous species and semiconducting electrode results in chemical modulation of the Fermi level. In such a case the functional relationship is a generalized form of the Nernst equation in which the slope of the dependence of measured potential on partial pressure of gas assumes fractional values. It is shown that an entire new class of solid state gas sensors can be based on this principle. RP Janata, J (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 26 TC 7 Z9 8 U1 0 U2 2 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 FEB PY 1997 VL 94 IS 1-4 BP 209 EP 215 DI 10.1016/S0167-2738(96)00503-6 PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WU966 UT WOS:A1997WU96600025 ER PT J AU Pruski, M Lang, DP Fernandez, C Amoureux, JP AF Pruski, M Lang, DP Fernandez, C Amoureux, JP TI Multiple-quantum magic-angle spinning NMR with cross-polarization: Spectral editing of high-resolution spectra of quadrupolar nuclei SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE multiple-quantum MAS NMR of quadrupolar nuclei; cross-polarization; aluminophosphate ID SOLID-STATE NMR; LOCKING AB An experiment is presented that combines the multiple-quantum magic-angle spinning (MQMAS) technique with cross-polarization (CP). As a preliminary test of this new method, we measured and compared the Al-27 3QMAS and F-19-->Al-27 CP 3QMAS spectra of a fluorinated AlPO4 aluminophosphate. Complete discrimination between the fluorinated and nonfluorinated Al sites was easily achieved, which demonstrates the usefulness of CP MQMAS for spectral editing. Future applications of this experiment will include other spin pairs and heteronuclear correlation NMR spectroscopy. (C) 1997 Elsevier Science B.V. C1 UNIV SCI & TECH LILLE FLANDRES ARTOIS,LAB DYNAM & STRUCT MAT MOL,CNRS,URA 801,F-59655 VILLENEUVE DASCQ,FRANCE. RP Pruski, M (reprint author), AMES LAB,230 SPEDDING HALL,AMES,IA 50011, USA. RI fernandez, christian/C-3158-2008 OI fernandez, christian/0000-0002-5476-3148 NR 23 TC 64 Z9 65 U1 0 U2 5 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 FEB PY 1997 VL 7 IS 4 BP 327 EP 331 DI 10.1016/S0926-2040(96)01284-2 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA WZ713 UT WOS:A1997WZ71300007 PM 9176938 ER PT J AU Jin, QH Duan, YX Olivares, JA AF Jin, QH Duan, YX Olivares, JA TI Development and investigation of microwave plasma techniques in analytical atomic spectrometry SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Review DE atomic absorption spectrometry; atomic emission spectrometry; atomic fluorescence spectrometry; microwave plasma; mass spectrometry ID ELEMENTAL MASS-SPECTROMETRY; SUPERCRITICAL FLUID CHROMATOGRAPHY; SPATIAL EMISSION PROPERTIES; INDUCTIVELY COUPLED PLASMA; SIMULTANEOUS MULTIELEMENT DETERMINATION; ATMOSPHERIC-PRESSURE ARGON; INDUCED NITROGEN DISCHARGE; ELECTRON NUMBER DENSITIES; CYLINDRICAL TM010 CAVITY; EASILY IONIZED ELEMENTS AB Microwave plasma (MWP) sources have found extensive use in spectrochemical analysis during the past decades. As the MWP offers some attractive features, it has been widely used either as an excitation source for atomic emission spectrometry (MWP-AES) or as an ionization source for mass spectrometry (MWP-MS). The use of MWPs as an atomization source for atomic absorption spectrometry (MWP-AAS) and atomic fluorescence spectrometry (MWP-AFS) has also appeared. The historical development and recent improvements in these MWP techniques are presented in this review with emphasis on the analytical performance, characteristics, interferences and applications. Research on the fundamental properties of MWPs is also given. Both the advantages and limitations of MWPs in atomic spectrometry are discussed. (C) 1997 Elsevier Science B.V. C1 JILIN UNIV,DEPT CHEM,CHANGCHUN 130023,PEOPLES R CHINA. RP Jin, QH (reprint author), LOS ALAMOS NATL LAB,CST 9,MS J514,LOS ALAMOS,NM 87545, USA. NR 242 TC 56 Z9 59 U1 2 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD FEB PY 1997 VL 52 IS 2 BP 131 EP 161 DI 10.1016/S0584-8547(96)01553-4 PG 31 WC Spectroscopy SC Spectroscopy GA WR973 UT WOS:A1997WR97300001 ER PT J AU Vasanthamohan, N Singh, JP AF Vasanthamohan, N Singh, JP TI Enhancement of critical current density and strain tolerance in Ag-sheathed BSCCO (2223) tapes by continuous silver reinforcement SO SUPERCONDUCTOR SCIENCE & TECHNOLOGY LA English DT Article ID SUPERCONDUCTING TAPES; COMPOSITES AB We have used a modified powder-in-tube technique in various configurations to demonstrate significant improvement in the transport properties and strain tolerance of Ag-sheathed BSCCO superconducting tapes. In this process, the BSCCO core has been reinforced with a silver rod placed concentrically within the silver tube and then processed into approximate to 250 mu m thick tapes by established metal-working techniques. A noticeable improvement in critical current density, J(c), was observed as a result of this modification. This increase is attributed to increased texturing, decrease in thickness of BSCCO layers, increase in the length of the Ag/BSCCO interface, and decrease in the volume fraction of the superconducting core which is less effective in contributing towards the overall critical current of the tape. Further improvements have been made to this configuration by incorporating another ring of superconductor into the core. The improved configurations led to a significant increase in J(c) over that of monolithic BSCCO tapes. Critical current densities of Fs:40 kA cm(-2) at 77 K and self-field have been consistently achieved in 150 mu m thick tapes after 150 h of sintering. Analysis of critical current through various sections of the tape indicates that 80% of the critical current is carried by the centre section of the core within which the Ag rod is located. The bend strain tolerance of the tapes containing a silver core was found to be significantly better than that of the monolithic tapes. At an applied surface bend strain of 1.0%, about 98% of initial J(c) was retained in Ag-reinforced tapes, compared with only 54% in monolithic tapes. C1 ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439. NR 24 TC 14 Z9 14 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-2048 J9 SUPERCOND SCI TECH JI Supercond. Sci. Technol. PD FEB PY 1997 VL 10 IS 2 BP 113 EP 118 DI 10.1088/0953-2048/10/2/008 PG 6 WC Physics, Applied; Physics, Condensed Matter SC Physics GA WK203 UT WOS:A1997WK20300008 ER PT J AU Baltrus, JP Diehl, JR AF Baltrus, JP Diehl, JR TI Surface spectroscopic studies of factors influencing xanthate adsorption on coal pyrite surfaces SO SURFACE AND INTERFACE ANALYSIS LA English DT Article; Proceedings Paper CT Surface Analysis 96 CY JUN 12-14, 1996 CL ANN ARBOR, MI SP Amer Vacuum Soc, Appl Surf Sci Div, Amer Vacuum Soc, Mich Chapter DE coal; pyrite; xanthate; XPS ID SULFIDE MINERALS; AQUEOUS-SOLUTION; PHOTOELECTRON; ETHYLXANTHATE; VIBRATION; FLOTATION; OXIDATION; IONS AB The relative adsorption of fluoroxanthates on several different coal pyrites has been found to depend on the degree to which the pyrite surfaces are oxidized. Maximum xanthate adsorption occurs in the absence of pyrite surface oxidation and is affected by the presence of polysulfides and metal-deficient sulfides on the pyrite surface. The structure and electronic properties of the xanthate molecule may also affect its adsorption. 3-(Trifluoromethyl)benzyl xanthate was found to selectively adsorb on pyrite vs. coal surfaces. Secondary ion mass spectrometry is a viable alternative to x-ray photoelectron spectroscopy for detecting xanthate adsorption. (C) 1997 by John Wiley & Sons, Ltd. RP Baltrus, JP (reprint author), US DOE,PITTSBURGH ENERGY TECHNOL CTR,POB 10940,PITTSBURGH,PA 15236, USA. NR 27 TC 6 Z9 6 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD FEB PY 1997 VL 25 IS 2 BP 64 EP 70 DI 10.1002/(SICI)1096-9918(199702)25:2<64::AID-SIA203>3.0.CO;2-9 PG 7 WC Chemistry, Physical SC Chemistry GA WM028 UT WOS:A1997WM02800003 ER PT J AU Dumas, P Suhren, M Chabal, YJ Hirschmugl, CJ Williams, GP AF Dumas, P Suhren, M Chabal, YJ Hirschmugl, CJ Williams, GP TI Adsorption and reactivity of NO on Cu(111): A synchrotron infrared reflection absorption spectroscopic study SO SURFACE SCIENCE LA English DT Article DE chemisorption; copper; infrared absorption spectroscopy; nitrogen oxides; solid-gas interfaces; surface chemical reaction; thermal desorption; vibrations of adsorbed molecules ID ENERGY ELECTRON-DIFFRACTION; ADSORBATE-INDUCED CHANGES; NITRIC-OXIDE; CHEMISORBED MOLECULES; SURFACE RESISTIVITY; LOW-TEMPERATURES; NI(111) SURFACE; COVERED NI(111); COADSORBED NO; AG(111) AB Infrared reflection absorption spectroscopy of NO adsorbed on Cu(111) has been performed in the frequency range 200-2500 cm(-1). At low temperatures (T < 120 K), two different states were identified with increasing coverage: adsorption followed by dissociation. At coverages up to one monolayer, NO molecules adsorb on identical sites, which are suggested to be of threefold symmetry, with an upright geometry. Two ordered overlayers are formed in turn: p(3 x 3) and (root 7 x root 7)R19.1 degrees. The infrared spectra show two absorption bands: the internal stretching made of NO, which shifts upwards in frequency with increasing coverage, and a low frequency anti-absorption band. The anti-absorption band is assigned, based on its isotopic frequency dependence, to the hindered rotation of the NO molecules. After completion of the monolayer, the NO molecules react and adsorbed N2O molecules are found on the surface bound through the oxygen atom (Cu-ON2 stretching mode at 352 cm(-1)) with their molecular axis (O-N-N) parallel to the surface plane. Desorption of the adsorbed N2O occurs at 120 K. NO dimers, which are the reaction intermediates in the formation of N2O from NO, have been clearly identified. C1 CNRS,LASIR,F-94320 THIAIS,FRANCE. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Dumas, P (reprint author), CTR UNIV PARIS SUD,LURE,F-94320 THIAIS,FRANCE. RI Chabal, Yves/A-5998-2011 OI Chabal, Yves/0000-0002-6435-0347 NR 79 TC 89 Z9 89 U1 0 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 1997 VL 371 IS 2-3 BP 200 EP 212 DI 10.1016/S0039-6028(96)00987-9 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WE531 UT WOS:A1997WE53100004 ER PT J AU Lyman, PF Bedzyk, MJ AF Lyman, PF Bedzyk, MJ TI Local structure of Sn/Si(001) surface phases SO SURFACE SCIENCE LA English DT Article DE Auger electron spectroscopy; low-index single crystal surfaces; photon absorption spectroscopy; silicon; surface relaxation and reconstruction; surface structure, morphology, roughness and topography; tin; X-ray scattering diffraction and reflection ID MOLECULAR-BEAM-EPITAXY; SI(100) SURFACE; PB/GE(001) SYSTEM; SN; SUPERSTRUCTURES; GE; HETEROSTRUCTURES; SUPERLATTICES; ADSORPTION; COVERAGE AB The surface structures of the (6 x 2), c(8 x 4) and (5 x 1) phases of Sn/Si(001) were studied using the X-ray standing wave technique. Using the (004) and (022) Bragg reflections, we find that the (6 x 2) and c(8 x 4) phases are composed of highly buckled Sn-Sn ad-dimers located 1.58 Angstrom above the bulk-like Si(004) surface atomic plane. The Sn atoms occupy two distinct sites with a vertical separation of 0.68 Angstrom, resulting in a dimer buckling angle of approximately 14 degrees. Occupation of second-layer sites by Sn in the (5 x 1) phase, and even in the high-coverage region of the c(8 x 4) phase, changes the Sn spatial distribution normal to the surface, which we attribute to unbuckling and/or breaking of the dimers in the first layer. C1 NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. NORTHWESTERN UNIV,CTR MAT RES,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RI Bedzyk, Michael/B-7503-2009; Bedzyk, Michael/K-6903-2013 NR 32 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 1997 VL 371 IS 2-3 BP 307 EP 315 DI 10.1016/S0039-6028(96)01007-2 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WE531 UT WOS:A1997WE53100014 ER PT J AU Kim, YJ Gao, Y Chambers, SA AF Kim, YJ Gao, Y Chambers, SA TI Selective growth and characterization of pure, epitaxial alpha-Fe2O3(0001) and Fe3O4(001) films by plasma-assisted molecular beam epitaxy SO SURFACE SCIENCE LA English DT Article DE electron-solid diffraction; iron oxide; molecular beam epitaxy; photoelectron spectroscopy; single crystal epitaxy ID SCANNING-TUNNELING-MICROSCOPY; RAY PHOTOELECTRON DIFFRACTION; IRON-OXIDE SURFACES; ELECTRON DIFFRACTION; AUGER; ENERGY; MGO(001); PT(111); CRYSTALLOGRAPHY; PHOTOEMISSION AB Pure-phase, single-crystalline epitaxial films of alpha-Fe2O3(0001) and Fe3O4(001) have been grown on Al2O3(0001) and MgO(001) substrates, respectively, using oxygen-plasma-assisted molecular beam epitaxy. We discuss the growth conditions required to synthesize these phases, as well as the associated characterization by means of reflection high-energy electron diffraction, low-energy electron diffraction, and X-ray photoelectron spectroscopy and diffraction. The selective growth of these phases depends critically on the choice of substrate, the iron and oxygen fluxes, and the substrate temperature. MgO(001) and Al2O3(0001) were chosen as substrates for the growth of Fe3O4(001) and alpha-Fe2O3(0001), respectively, because of good lattice and crystal symmetry matching. The growth of alpha-Fe2O3 is achieved using a low iron-to-oxygen flux ratio compared with that used to grow Fe3O4. Fe3O4 must be grown at the relatively low substrate temperature of 250 degrees C on MgO(001) to avoid interface reaction and Mg outdiffusion. The alpha-Fe2O3 film surface is unreconstructed whereas the Fe3O4 surface exhibits a (root 2 x root 2)R45 reconstruction. Application of a simple electron counting rule to the Fe3O4(001) surface suggests that the reconstruction is due to an ordered array of tetrahedral Fe vacancies. C1 PACIFIC NW NATL LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 40 TC 121 Z9 121 U1 2 U2 34 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 1997 VL 371 IS 2-3 BP 358 EP 370 DI 10.1016/S0039-6028(96)00999-5 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WE531 UT WOS:A1997WE53100019 ER PT J AU Adams, DP Mayer, TM Chason, E Kellerman, BK Swartzentruber, BS AF Adams, DP Mayer, TM Chason, E Kellerman, BK Swartzentruber, BS TI Island structure evolution during chemical vapor deposition SO SURFACE SCIENCE LA English DT Article DE chemical vapor deposition; growth; iron; nucleation; scanning tunneling microscopy; silicon ID SCANNING-TUNNELING-MICROSCOPY; MOLECULAR-BEAM EPITAXY; METALLIC FEATURES; SURFACE; GROWTH; SI(001); NUCLEATION; DESORPTION; ADSORPTION; DISILANE AB Scanning tunneling microscopy (STM) and Monte Carlo simulations are used to investigate the development of island structure during low-pressure, chemical vapor deposition (CVD) of metal onto clean Si(100) substrates. For Fe growth via Fe(CO)(5) pyrolysis, STM shows that precursor molecules initially decompose at Si dangling bond sites. The nucleation rate is strongly dependent on substrate temperature with rapid decomposition al 200 degrees C and zero reaction at room temperature (for exposures as large as 100 L). At later stages STM shows that island structure is dominated by differential reaction probabilities. A small barrier to decomposition on Fe compared with Si leads to large clusters and a nonlinear growth rate. This autocatalytic growth behavior is also reflected in the measured island size distributions. Kinetic Monte Carlo simulations confirm that chemical reaction kinetics influence Fe film growth, while precursor molecule diffusion does not play a major role in the evolution of island structure. Using simulations, we also demonstrate how CVD film structure can differ from that developed during solid-source molecular beam epitaxy. RP Adams, DP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 45 TC 21 Z9 21 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 1997 VL 371 IS 2-3 BP 445 EP 454 DI 10.1016/S0039-6028(96)01005-9 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WE531 UT WOS:A1997WE53100028 ER PT J AU Rosenfeld, AH Romm, JJ Akbari, H Lloyd, AC AF Rosenfeld, AH Romm, JJ Akbari, H Lloyd, AC TI Paint the town white - And green SO TECHNOLOGY REVIEW LA English DT Article C1 UNIV NEVADA,DESERT RES INST,ENERGY & ENVIRONM ENGN CTR,RENO,NV 89506. RP Rosenfeld, AH (reprint author), US DOE,LAWRENCE BERKELEY LAB,WASHINGTON,DC 20585, USA. NR 0 TC 3 Z9 4 U1 1 U2 1 PU MASS INST TECHNOL PI CAMBRIDGE PA BUILDING W59, CAMBRIDGE, MA 02139 SN 0040-1692 J9 TECHNOL REV JI Technol. Rev. PD FEB-MAR PY 1997 VL 100 IS 2 BP 52 EP 59 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WG148 UT WOS:A1997WG14800025 ER PT J AU Morris, MD AF Morris, MD TI Editor's report SO TECHNOMETRICS LA English DT Editorial Material RP Morris, MD (reprint author), OAK RIDGE NATL LAB,MATH SCI SECT,POB 2008,BLDG 6012,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 SN 0040-1706 J9 TECHNOMETRICS JI Technometrics PD FEB PY 1997 VL 39 IS 1 BP 1 EP 2 PG 2 WC Statistics & Probability SC Mathematics GA WE555 UT WOS:A1997WE55500001 ER PT J AU Garrett, KA Dixon, PM AF Garrett, KA Dixon, PM TI Environmental pseudointeraction: The effects of ignoring the scale of environmental heterogeneity in competition studies SO THEORETICAL POPULATION BIOLOGY LA English DT Article ID NEIGHBORHOOD PREDICTORS; SPATIAL HETEROGENEITY; DENSITY-DEPENDENCE; MODELS; INTERFERENCE; PATTERN; DISTRIBUTIONS; COMMUNITIES; PREDATION; ECOLOGY AB Spatially explicit models of competition such as neighborhood and area-of-influence models are useful approaches for gaining insight into interactions between individual organisms. The environments in which these models are parameterized may be spatially heterogeneous. We demonstrate that, even in the absence of interaction between individuals, nonzero estimates of competitive or facilitative coefficients can result from environmental heterogeneity when densities are not experimentally imposed. We show this using a model of individual position and size in a simple environment composed of two patch types. Suppose two noninteracting species are intermixed in the study area and species 1 becomes established more readily in the patch type in which species 2 grows larger and has higher fecundity. Analyses that ignore environmental heterogeneity may indicate that species 1 facilitates species 2 because larger individuals of species 2 will tend to be associated with greater numbers of species 1. Similarly, environmental pseudocompetition can result if species 2 is more frequent among small individuals of species 1. The strength of the environmental pseudointeraction depends on (a) the magnitude of the size and fecundity differences between patch types, (b) the magnitude of the establishment differences between patch types, and (c) the size, relative to the environmental grain, of the neighborhood or quadrat used for sampling the number of competitor individuals. (C) 1997 Academic Press. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. NR 40 TC 6 Z9 6 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 0040-5809 EI 1096-0325 J9 THEOR POPUL BIOL JI Theor. Popul. Biol. PD FEB PY 1997 VL 51 IS 1 BP 37 EP 48 DI 10.1006/tpbi.1997.1295 PG 12 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA WU353 UT WOS:A1997WU35300004 ER PT J AU Vianco, PT AF Vianco, PT TI Revised manual to answer structural soldering questions SO WELDING JOURNAL LA English DT Editorial Material RP Vianco, PT (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD FEB PY 1997 VL 76 IS 2 BP 104 EP 104 PG 1 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA WF785 UT WOS:A1997WF78500021 ER PT J AU Alber, T Appelshauser, H Bachler, J Bartke, J Bialkowska, H Bloomer, MA Bock, R Braithwaite, WJ Brinkmann, D Brockmann, R Buncic, P Chan, P Chase, SI Cramer, PB Cramer, JG Derado, I Eberlein, B Eckardt, V Eschke, J Ferenc, D Fleischmann, B Foka, P Freund, P Fuchs, M Gazdzicki, M Gladysz, E Gunther, J Harris, JW Hoffman, M Jacobs, P Kabana, S Kadija, K Kosiec, J Kowalski, M Kuhmichel, A Lahanas, M Lee, JY Ljubicic, A Margetis, S Mitchell, JT Morse, R Nappi, E Odyniec, G Paic, G Panagiotou, AD Petridis, A Piper, A Posa, F Poskanzer, AM Pugh, HG Puhlhofer, F Rai, G Rauch, W Renfordt, R Retyk, W Rohrich, D Roland, G Rothard, H Runge, K Sandoval, A Schambach, J Schmitz, N Schmoetten, E Schneider, I Sendelbach, R Seyboth, P Seyerlein, J Skrzypczak, E Stefansky, P Stock, R Strobele, H Teitelbaum, L Tonse, S Trainor, TA Vasileiadis, G Vassiliou, M Vranic, D Wenig, S Wensveen, M Wosiek, B AF Alber, T Appelshauser, H Bachler, J Bartke, J Bialkowska, H Bloomer, MA Bock, R Braithwaite, WJ Brinkmann, D Brockmann, R Buncic, P Chan, P Chase, SI Cramer, PB Cramer, JG Derado, I Eberlein, B Eckardt, V Eschke, J Ferenc, D Fleischmann, B Foka, P Freund, P Fuchs, M Gazdzicki, M Gladysz, E Gunther, J Harris, JW Hoffman, M Jacobs, P Kabana, S Kadija, K Kosiec, J Kowalski, M Kuhmichel, A Lahanas, M Lee, JY Ljubicic, A Margetis, S Mitchell, JT Morse, R Nappi, E Odyniec, G Paic, G Panagiotou, AD Petridis, A Piper, A Posa, F Poskanzer, AM Pugh, HG Puhlhofer, F Rai, G Rauch, W Renfordt, R Retyk, W Rohrich, D Roland, G Rothard, H Runge, K Sandoval, A Schambach, J Schmitz, N Schmoetten, E Schneider, I Sendelbach, R Seyboth, P Seyerlein, J Skrzypczak, E Stefansky, P Stock, R Strobele, H Teitelbaum, L Tonse, S Trainor, TA Vasileiadis, G Vassiliou, M Vranic, D Wenig, S Wensveen, M Wosiek, B TI A new Coulomb correction method for Bose-Einstein correlations, based on the pi(+)pi(-) correlation measurements SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; PION INTERFEROMETRY; NA35 AB We present the measured correlation functions for pi(+)pi(-), pi(-)pi(-) and pi(+)pi(+) pairs in central S+Ag collisions at 200 GeV per nucleon. The Gamov function, which has been traditionally used to correct the correlation functions of charged pions for the Coulomb interaction, is found to be inconsistent with all measured correlation functions. Certain problems which have been dominating the systematic uncertainty of the correlation analysis are related to this inconsistency. It is demonstrated that a new Coulomb correction method, based exclusively on the measured correlation function for pi(+)pi(-) pairs, may solve the problem. C1 UNIV ATHENS,DEPT PHYS,GR-15771 ATHENS,GREECE. UNIV BARI,DIPARTMENTO FIS,I-70126 BARI,ITALY. IST NAZL FIS NUCL,I-70126 BARI,ITALY. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. INST NUCL PHYS,PL-30055 KRAKOW,POLAND. GSI DARMSTADT,D-64220 DARMSTADT,GERMANY. UNIV FRANKFURT,FACHBEREICH PHYS,D-60486 FRANKFURT,GERMANY. UNIV FREIBURG,FAK PHYS,D-79104 FREIBURG,GERMANY. UNIV WASHINGTON,DEPT PHYS,PHYS NUCL LAB,SEATTLE,WA 98195. UNIV WARSAW,INST EXPT PHYS,PL-00681 WARSAW,POLAND. INST NUCL STUDIES,PL-00681 WARSAW,POLAND. RUDJER BOSKOVIC INST,ZAGREB 10000,CROATIA. UNIV MARBURG,FACHBEREICH PHYS,D-35032 MARBURG,GERMANY. RP Alber, T (reprint author), MAX PLANCK INST PHYS & ASTROPHYS,D-80805 MUNICH,GERMANY. NR 23 TC 12 Z9 12 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD FEB PY 1997 VL 73 IS 3 BP 443 EP 448 DI 10.1007/s002880050333 PG 6 WC Physics, Particles & Fields SC Physics GA WL970 UT WOS:A1997WL97000006 ER PT J AU Berger, E Blair, R Fuess, T Guarino, V Hill, N Magill, S May, E Nodulman, L Price, L Proudfoot, J Stanek, R Underwood, D Wagner, R Wicklund, B Blanchot, G Bosman, M Casado, P CavalliSforza, M Efthymiopoulos, I Ivanyushenkov, Y Juste, A Miralles, L Orteu, S Padilla, C Perlas, JA Riu, I Ronceux, B Teubert, F Arsenescu, R Constantinescu, S Blaj, C Boldea, V Dita, S Cobal, M Gildemeister, O Nessi, M Henriques, A Poggioli, L Sonderegger, P Karapetian, G Anderson, K Blucher, E Evans, H Merritt, F Pilcher, J Sanders, H Shochet, M Tang, F Turcot, A Wagner, D Ajaltouni, Z Badaud, F Bouhemaid, N Brette, P Brossard, M Chadelas, R Chevaleyre, JC Crouau, M Daudon, F Dugne, JJ Michel, B Montarou, G Muanza, GS Pallin, D PlothowBesch, H Poirot, S Reinmuth, G Says, LP Vazeille, F Astvatsaturov, A Borisov, O Budagov, J ChirikovZorin, I Chlachidze, G Glagolev, V Kakurin, S Kolomoets, V Kovtun, V Kukhtin, V Lebedev, A Liba, I Lomakina, O Lomakin, Y Malyukov, S Minashvili, I Pantea, D Pukhov, O Romanov, V Russakovich, N Senchishin, V Semenov, A Sissakian, A Shchelchkov, A Shevtsov, V Studenov, S Tokar, S Topilin, N Vinogradov, V Vorozhtsov, S Yarygin, G Cogswell, F Downing, R Errede, D Errede, S Haney, M Simaitis, V Thaler, J Amaral, P Amorim, A Carvalho, J David, M Gomes, A Maio, A Martins, JP Onofre, A Wolters, H Bromberg, C Huston, J Miller, R Richards, R Yosef, C Alifanov, A Bogush, A Golubev, V Rumyantsev, V Kulchitsky, Y Angelini, C Autiero, D Cavasinni, V Costanzo, D DeSanto, A DelPrete, T DiGirolamo, B Flaminio, V Lami, S Lazzeroni, C Mazzoni, E Renzoni, G Davidek, T Dolejsi, J Dolezal, Z Leitner, R Soustruznik, K Suk, M Tas, P Trka, Z Valkar, S Zdrazil, M Lokajicek, M Nemecek, S Karyukhin, A Klyukhin, V Khokhlov, Y Kopikov, S Kostrikov, M Lapin, V Protopopov, Y Sidorov, V Solodkov, A Starchenko, E Surkov, A Zaitsev, A Caloba, L Gaspar, M Marroquin, F Pereira, A Seixas, JM Berglund, S Bohm, C Johansson, E Hellman, S Holmgren, S JonAnd, K Sellden, B Tardel, S Yamdagni, N Ferrer, A Honore, PF Albiol, F De, K Gallas, E Li, J Sawyer, L Stephens, R Turcotte, M White, A Hakopian, H Grabsky, V Mnatsakanian, E Vartapetian, A AF Berger, E Blair, R Fuess, T Guarino, V Hill, N Magill, S May, E Nodulman, L Price, L Proudfoot, J Stanek, R Underwood, D Wagner, R Wicklund, B Blanchot, G Bosman, M Casado, P CavalliSforza, M Efthymiopoulos, I Ivanyushenkov, Y Juste, A Miralles, L Orteu, S Padilla, C Perlas, JA Riu, I Ronceux, B Teubert, F Arsenescu, R Constantinescu, S Blaj, C Boldea, V Dita, S Cobal, M Gildemeister, O Nessi, M Henriques, A Poggioli, L Sonderegger, P Karapetian, G Anderson, K Blucher, E Evans, H Merritt, F Pilcher, J Sanders, H Shochet, M Tang, F Turcot, A Wagner, D Ajaltouni, Z Badaud, F Bouhemaid, N Brette, P Brossard, M Chadelas, R Chevaleyre, JC Crouau, M Daudon, F Dugne, JJ Michel, B Montarou, G Muanza, GS Pallin, D PlothowBesch, H Poirot, S Reinmuth, G Says, LP Vazeille, F Astvatsaturov, A Borisov, O Budagov, J ChirikovZorin, I Chlachidze, G Glagolev, V Kakurin, S Kolomoets, V Kovtun, V Kukhtin, V Lebedev, A Liba, I Lomakina, O Lomakin, Y Malyukov, S Minashvili, I Pantea, D Pukhov, O Romanov, V Russakovich, N Senchishin, V Semenov, A Sissakian, A Shchelchkov, A Shevtsov, V Studenov, S Tokar, S Topilin, N Vinogradov, V Vorozhtsov, S Yarygin, G Cogswell, F Downing, R Errede, D Errede, S Haney, M Simaitis, V Thaler, J Amaral, P Amorim, A Carvalho, J David, M Gomes, A Maio, A Martins, JP Onofre, A Wolters, H Bromberg, C Huston, J Miller, R Richards, R Yosef, C Alifanov, A Bogush, A Golubev, V Rumyantsev, V Kulchitsky, Y Angelini, C Autiero, D Cavasinni, V Costanzo, D DeSanto, A DelPrete, T DiGirolamo, B Flaminio, V Lami, S Lazzeroni, C Mazzoni, E Renzoni, G Davidek, T Dolejsi, J Dolezal, Z Leitner, R Soustruznik, K Suk, M Tas, P Trka, Z Valkar, S Zdrazil, M Lokajicek, M Nemecek, S Karyukhin, A Klyukhin, V Khokhlov, Y Kopikov, S Kostrikov, M Lapin, V Protopopov, Y Sidorov, V Solodkov, A Starchenko, E Surkov, A Zaitsev, A Caloba, L Gaspar, M Marroquin, F Pereira, A Seixas, JM Berglund, S Bohm, C Johansson, E Hellman, S Holmgren, S JonAnd, K Sellden, B Tardel, S Yamdagni, N Ferrer, A Honore, PF Albiol, F De, K Gallas, E Li, J Sawyer, L Stephens, R Turcotte, M White, A Hakopian, H Grabsky, V Mnatsakanian, E Vartapetian, A TI A measurement of the energy loss spectrum of 150 GeV muons in iron SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID BREMSSTRAHLUNG; CALORIMETER AB The energy loss spectrum of 150 GeV muons has been measured with a prototype of the ATLAS hadron calorimeter in the H8 beam of the CERN SPS. The differential probability dP/d upsilon per radiation length of a fractional energy loss upsilon = Delta E(mu)E(upsilon) has been measured in the range upsilon = 0.01 divided by 0.95; it is compared with the theoretical predictions for energy losses due to bremsstrahlung and production of electron-positron pairs or of energetic knock-on electrons. The integrated probability integral(0.01)(0.95)(dP/d upsilon)d upsilon is (1.610 +/- 0.015(stat) +/- 0.105(syst)). 10(-3) in agreement with the theoretical predictions 1.556 . 10(-3) and 1.619 . 10(-3). Agreement with theory is also found in two intervals of upsilon where production of electron-positron pairs and knock-on electrons dominates. In the region of bremsstrahlung dominance (upsilon = 0.12 divided by 0.95) the measured integrated probability (1.160 +/- 0.040(stat) +/- 0.075(syst)). 10(-4) is in agreement with the theoretical value of 1.185 . 10(-4), obtained using the Petrukhin and Shestakov description of the bremsstrahlung process. The same result is about 3.6 standard deviations (defined as the quadratic sum of statistical and systematic errors) lower than the theoretical prediction of 1.472 . 10(-4) obtained using Tsai's description of bremsstrahlung. C1 UNIV AUTONOMA BARCELONA,INST FIS ALTES ENERGIES,E-08193 BELLATERRA,BARCELONA,SPAIN. INST ATOM PHYS,R-76900 BUCHAREST,ROMANIA. UNIV CHICAGO,CHICAGO,IL 60637. UNIV CLERMONT FERRAND,IN2P3,CNRS,LPC CLERMONT FERRAND,F-63177 CLERMONT FERRAN,FRANCE. JOINT INST NUCL RES DUBNA,RU-141980 DUBNA,MOSCOW REGION,RUSSIA. UNIV ILLINOIS,CHICAGO,IL 60680. UNIV LISBON,LIP,P-1699 LISBON,PORTUGAL. UNIV LISBON,FCUL,P-1699 LISBON,PORTUGAL. UNIV COIMBRA,LIP,P-3000 COIMBRA,PORTUGAL. UNIV COIMBRA,FCTUC,P-3000 COIMBRA,PORTUGAL. UNIV CAT FIGUEIRA DA FUZ,P-1700 LISBON,PORTUGAL. MICHIGAN STATE UNIV,E LANSING,MI 48824. INST PHYS ASB,MINSK,BYELARUS. IST NAZL FIS NUCL,I-56010 PISA,ITALY. UNIV PISA,I-56010 PISA,ITALY. CHARLES UNIV,CZ-18000 PRAGUE 8,CZECH REPUBLIC. ACAD SCI CZECH REPUBL,CZ-18040 PRAGUE 8,CZECH REPUBLIC. INST HIGH ENERGY PHYS,PROTVINO,RUSSIA. UNIV FED RIO DE JANEIRO,COPPE,EE,BR-21945 RIO JANEIRO,BRAZIL. UNIV STOCKHOLM,S-11346 STOCKHOLM,SWEDEN. IFIC VALENCIA,E-46100 BURJASSOT,VALENCIA,SPAIN. UNIV TEXAS,ARLINGTON,TX 76019. YEREVAN PHYS INST,YEREVAN 375036,ARMENIA. CERN,CH-1211 GENEVA 23,SWITZERLAND. RP Berger, E (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI David, Mario/C-4664-2012; Klyukhin, Vyacheslav/D-6850-2012; Wolters, Helmut/M-4154-2013; De, Kaushik/N-1953-2013; Nemecek, Stanislav/G-5931-2014; Bosman, Martine/J-9917-2014; Cavalli-Sforza, Matteo/H-7102-2015; Ferrer, Antonio/H-2942-2015; Carvalho, Joao/M-4060-2013; Solodkov, Alexander/B-8623-2017; Zaitsev, Alexandre/B-8989-2017; Karyukhin, Andrey/J-3904-2014; OI Klyukhin, Vyacheslav/0000-0002-8577-6531; Wolters, Helmut/0000-0002-9588-1773; De, Kaushik/0000-0002-5647-4489; Bosman, Martine/0000-0002-7290-643X; Ferrer, Antonio/0000-0003-0532-711X; Carvalho, Joao/0000-0002-3015-7821; Solodkov, Alexander/0000-0002-2737-8674; Zaitsev, Alexandre/0000-0002-4961-8368; Gomes, Agostinho/0000-0002-5940-9893; Karyukhin, Andrey/0000-0001-9087-4315; Maio, Amelia/0000-0001-9099-0009; Amorim, Antonio/0000-0003-0638-2321; Colomer, Kiko Albiol/0000-0002-3824-2246 NR 20 TC 6 Z9 6 U1 2 U2 4 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD FEB PY 1997 VL 73 IS 3 BP 455 EP 463 DI 10.1007/s002880050335 PG 9 WC Physics, Particles & Fields SC Physics GA WL970 UT WOS:A1997WL97000008 ER PT J AU Poirier, B Miller, WH AF Poirier, B Miller, WH TI Optimized preconditioners for Green function evaluation in quantum reactive scattering calculations SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DISCRETE-VARIABLE REPRESENTATION; NONSYMMETRIC LINEAR-SYSTEMS; POTENTIAL-ENERGY SURFACE; REACTION PROBABILITIES; DISSOCIATION; COLLISIONS AB The optimal separable basis methodology is suggested for the efficient quantum-mechanical calculation of reactive and inelastic scattering amplitudes. The method gives rise to an optimally convergent distorted wave Born expansion of the Green's function. Computationally, this corresponds to an optimized DVR matrix preconditioning scheme. State-to-state and cumulative reactive scattering results are presented for the benchmark collinear H + H-2 --> H-2 + H system. CPU time and memory requirements are drastically reduced in comparison with other methods, and results are obtained for previously prohibitive energy regimes. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Poirier, B (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 20 TC 37 Z9 37 U1 0 U2 6 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 JAN 31 PY 1997 VL 265 IS 1-2 BP 77 EP 83 DI 10.1016/S0009-2614(96)01408-X PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF500 UT WOS:A1997WF50000012 ER PT J AU Scherer, JJ Rakestraw, DJ AF Scherer, JJ Rakestraw, DJ TI Cavity ringdown laser absorption spectroscopy detection of formyl (HCO) radical in a low pressure name SO CHEMICAL PHYSICS LETTERS LA English DT Article ID FLIGHT MASS-SPECTROSCOPY; INDUCED FLUORESCENCE; PHOTODISSOCIATION; PREDISSOCIATION; ACETALDEHYDE; SILICIDES; STATE; NM AB The formyl radical has been detected via the (A) over tilde - (X) over tilde system in a low pressure CH4/N-2/O-2 flame using cavity ringdown laser absorption spectroscopy. The direct absorption data obtained in these initial studies allows determination of the absolute HCO concentration in the flame of ca. 2.1(+/- 0.9) x 10(13) mol cm(-3), which is in excellent agreement with flame chemistry simulations. The extrapolated detection limit at 300 K of approximate to 1.4(+/-0.6) x 10(11) mol cm(-3) is comparable to that of other methods, including intracavity laser absorption spectroscopy. RP Scherer, JJ (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,M-S 9055,LIVERMORE,CA 94551, USA. NR 35 TC 65 Z9 65 U1 0 U2 10 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 JAN 31 PY 1997 VL 265 IS 1-2 BP 169 EP 176 DI 10.1016/S0009-2614(96)01403-0 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF500 UT WOS:A1997WF50000025 ER PT J AU Zhang, W Rashid, KA Haque, M Siddiqi, AH Vinogradov, SN Moens, L LaMar, GN AF Zhang, W Rashid, KA Haque, M Siddiqi, AH Vinogradov, SN Moens, L LaMar, GN TI Solution of H-1 NMR structure of the heme cavity in the oxygen-avid myoglobin from the trematode Paramphistomum epiclitum SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; CARBON-MONOXIDE COMPLEX; SPERM WHALE MYOGLOBIN; ASCARIS HEMOGLOBIN; ELECTRONIC-PROPERTIES; RESOLUTION; SPECTROSCOPY; ASSIGNMENT; SUBSTITUTION; SEQUENCES AB A two-dimensional H-1 NMR study has been carried out on the heme cavity of the extreme oxygen-avid and autoxidation-resistant oxy-myoglobin complex from the trematode Paramphistomum epiclitum, and the residues were identified which potentially provide hydrogen bond stabilization for the bound oxygen. Complete assignment of the heme core resonances allows the identification of 10 key heme pocket residues, 4 Phe, 4 Tyr, and 2 upfield ring current aliphatic side chains. Based solely on the conserved myoglobin folding topology that places the E helix-heme crossover and the completely conserved Phe(CD1)-heme contact at opposing meso positions, the heme orientation in the cavity and the E helix alignment were unambiguously established that place Tyr(66) at position E7. Moreover, all eight aromatic and the two aliphatic side chains were shown to occupy the positions in the heme cavity predicted by amino acid sequence alignment with globins of known tertiary structure. The dipolar contacts for the Tyr(32)(B10) and Tyr(66)(E7) rings indicate that both residues are oriented into the heme cavity, which is unprecedented in globins. The ring hydroxyl protons for both Tyr are close to each other and in a position to provide hydrogen bonds to the coordinated oxygen, as supported by strong retardation of their exchange rate with bulk solvent. A more crowded and compact structure increases the dynamic stability of the distal pocket and may contribute to the autoxidation resistance of this myoglobin. C1 LAWRENCE LIVERMORE NATL LAB,DEPT CHEM,DAVIS,CA 95616. UNIV ANTWERP,DEPT BIOCHEM,B-2610 ANTWERP,BELGIUM. ALIGARH MUSLIM UNIV,DEPT ZOOL,ALIGARH 202002,UTTAR PRADESH,INDIA. WAYNE STATE UNIV,SCH MED,DEPT BIOCHEM,DETROIT,MI 48201. FU NHLBI NIH HHS [HL 16087] NR 35 TC 16 Z9 18 U1 2 U2 2 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 31 PY 1997 VL 272 IS 5 BP 3000 EP 3006 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WE667 UT WOS:A1997WE66700061 PM 9006948 ER PT J AU Zheng, YJ Ornstein, RL Leary, JA AF Zheng, YJ Ornstein, RL Leary, JA TI A density functional theory investigation of metal ion binding sites in monosaccharides SO JOURNAL OF MOLECULAR STRUCTURE-THEOCHEM LA English DT Article DE density functional theory; metal-carbohydrate interaction; carbohydrate-binding protein; monosaccharides; cis-inositol; beta-D-glucose ID TANDEM MASS-SPECTROMETRY; LINKAGE POSITION DETERMINATION; ALDOSE KETOSE ISOMERIZATION; XYLOSE ISOMERASE; SEMIEMPIRICAL CALCULATIONS; CARBOHYDRATE ANTIGENS; SUGAR CHAINS; MECHANISM; GLYCOPROTEINS; DISACCHARIDES AB The density functional theory method is used to study metal ion binding to simple carbohydrates such as cis-inositol and beta-D-glucose. The complexes formed between Be2+, Mg2+, Ca2+, and Li+ and cis-inositol and the complexes formed between Ca2+ and beta-D-glucose are optimized and metal binding sites are identified. There are two metal binding sites in cis-inositol and five in beta-D-glucose. Our calculations demonstrate that smaller ions such as Be2+ prefer to bind in the ax-ax-ax site of cis-inositol, while larger ions such Mg2+ and Li+ favor the ax-eq-ax site of cis-inositol. The preferred metal binding site in Ca2+-cis-inositol is defined by four hydroxyl groups instead of three (one equatorial and three axial OH). Among the five metal binding sites in beta-D-glucose, the one defined by the ring oxygen atom, C1-OH and C6-OH is the most preferred site where Ca2+ binds to three oxygen atoms. This tendency of metal ions to maximize interactions with carbohydrate ligands in the gas phase is in agreement with previous experimental and theoretical studies. The relevance of these metal-carbohydrate interactions in cell surface carbohydrate-binding proteins is also discussed. This study has demonstrated that the density functional theory method is a good method for identifying metal ion binding sites in carbohydrates. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. NR 43 TC 17 Z9 19 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 J MOL STRUC-THEOCHEM JI Theochem-J. Mol. Struct. PD JAN 31 PY 1997 VL 389 IS 3 BP 233 EP 240 DI 10.1016/S0166-1280(96)04707-0 PG 8 WC Chemistry, Physical SC Chemistry GA WQ197 UT WOS:A1997WQ19700004 ER PT J AU Zhang, HZ AF Zhang, HZ TI Unification Yang-Mills groups and representations with CP as a gauge symmetry SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article ID ANOMALY-FREE THEORIES; NON-ABELIAN VORTICES; QUANTUM COHERENCE; STRING THEORY; BLACK-HOLES; DIMENSIONS; MODELS; AXION; CONSERVATION; CANCELLATION AB We investigate more generally the possible unification Yang-Mills groups G(YM) and rep resentations with CP as a gauge symmetry. Besides the possible Yang-Mills groups E(8), E(7), SO(2n + 1), SO(4n), SP(2n), G(2) or F-4 (or a product of them) which only allow self-contragredient representations, we present other unification groups G(YM) and representations which may allow CP as a gauge symmetry. These include especially SU(N) containing Weyl fermions and their CP conjugates from low energy spectra in a basic irreducible representation (IR). Such an example is the 496-dimensional basic IR (on antisymmetric tensors of rank two) of SU(32) containing SO(32) as a subgroup in the adjoint IR, or SU(248) in a fundamental IR containing E(8) as a subgroup in the adjoint IR Our consideration also leads to the construction of a physical operator (CP) intrinsically as an inner automorphism of order higher than two for the unification group. We have also generalized the possible groups as unification G(YM) to include nonsemisimple Lie groups with CP arising as a gauge symmetry. In this case with U(1) ideals in the G(YM), we found that the U-Y(1) for weak hypercharge in the standard model or a U(1) gauge symmetry at low energies in general is traceless. Possible relevance to superstring theory is also briefly discussed. We expect that our results may open new alternatives for unified model building, especially with deeper or more generalized understanding of anomaly-free theories. C1 JACKSON STATE UNIV, DEPT PHYS & ATMOSPHER SCI, JACKSON, MS 39217 USA. RP Zhang, HZ (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, T-8, LOS ALAMOS, NM 87545 USA. NR 77 TC 1 Z9 1 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JAN 30 PY 1997 VL 12 IS 3 BP 557 EP 584 DI 10.1142/S0217751X97000542 PG 28 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA WB435 UT WOS:A1997WB43500003 ER PT J AU Michiels, J Gschneidner, KA AF Michiels, J Gschneidner, KA TI Electrical properties of yttrium sesquisulfide (Y2S3) mechanically alloyed with copper, boron, and aluminum SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE Y2S3-doped alloys; Al doping; electrical resistivity; thermoelectric power; Hall coefficient ID THERMOELECTRIC PROPERTIES; AMORPHIZATION AB The electrical resistivity, thermoelectric power (Seebeck coefficient) and Hall effect have been measured for (Y2S3)(1-y)X(y) compounds with the 6-monoclinic structure (where X = Cu, B or Al and y = 0.05 for Cu and B, and 0.025 less than or equal to y less than or equal to 0.075 for Al) in order to determine their potential as high temperature (300-1000 degrees C) thermoelectric materials. The Cu- and B-doped Y2S3 are insulators. The Al-doped Y2S3 behaves as a metastable degenerate semiconductor with itinerant conduction. The room temperature electrical resistivity decreases as the Al doping level increases, while the Seebeck coefficient remains constant at ca. 400 mu V degrees C-1. These materials, however, become insulators after a 2 week heat treatment at 1000 degrees C or higher. Both the electrical resistivity and Seebeck coefficient increased with increasing temperature, and exhibited lower values during the cool down run to room temperature. These data suggest that the (Y2S3)(1-y)Al-y alloys are in a metastable state in which the Al atoms occupy the interstitial sites of the Y2S3 lattice, where it acts as a current carrier donor. When heated, the Al atoms diffuse out of the lattice and no longer contribute to the electrical conductivity, thus making the alloy an insulator. The maximum value of the power factor was 0.6 mu W cm(-1)degrees C-Z, and decreased with increasing temperature. The results of this study indicate that Cu-, B-, and Al-doped Y2S3 are not useful as high temperature thermoelectric materials. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT MAT SCI & ENGN,AMES,IA 50011. NR 22 TC 0 Z9 2 U1 3 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JAN 30 PY 1997 VL 247 BP 9 EP 14 DI 10.1016/S0925-8388(96)02573-X PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA WQ566 UT WOS:A1997WQ56600003 ER PT J AU Pavelites, JJ Gao, JL Bash, PA Mackerell, AD AF Pavelites, JJ Gao, JL Bash, PA Mackerell, AD TI A molecular mechanics force field for NAD(+), NADH, and the pyrophosphate groups of nucleotides SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article ID ENERGY FUNCTION; DYNAMICS; NICOTINAMIDE; SIMULATIONS; ALCOHOLS; MOTION AB Empirical force field parameters for nicotinamide (NIC+) and 1,4-dihydronicotinamide (NIGH) were developed for use in modeling of the coenzymes nicotinamide adenine dinucleotide (NAD(+)) and NAD hydride (NADH). The parametrization follows the methodology used in the development of the CHARMM22 all-hydrogen parameters for proteins, nucleic acids, and lipids. Parametrization of inorganic phosphate for use in adenosine di- and triphosphates (e.g., ADP and ATP) is also presented. While high level ab initio data, such as conformational energies, dipole moments, interactions with water, and vibrational frequencies, were adequately reproduced by the developed parameters, strong emphasis was placed on the successful reproduction of experimental geometries and crystal data. Results for molecular dynamics crystal simulations were in good agreement with available crystallographic data. C1 UNIV MARYLAND,SCH PHARM,DEPT PHARMACEUT SCI,BALTIMORE,MD 21201. SUNY BUFFALO,DEPT CHEM,BUFFALO,NY 14260. ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. OI MacKerell, Alex/0000-0001-8287-6804 NR 33 TC 111 Z9 113 U1 0 U2 13 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0192-8651 J9 J COMPUT CHEM JI J. Comput. Chem. PD JAN 30 PY 1997 VL 18 IS 2 BP 221 EP 239 PG 19 WC Chemistry, Multidisciplinary SC Chemistry GA WB112 UT WOS:A1997WB11200007 ER PT J AU Zhong, CJ Zak, J Porter, MD AF Zhong, CJ Zak, J Porter, MD TI Voltammetric reductive desorption characteristics of alkanethiolate monolayers at single crystal Au(111) and (110) electrode surfaces SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE alkanethiolate monolayers; single crystal gold(111) and (110); voltammetric reductive desorption; binding sites ID SELF-ASSEMBLED MONOLAYERS; STRUCTURAL CHARACTERIZATION; ORGANOSULFUR COMPOUNDS; GOLD; ELECTROCHEMISTRY; DIFFRACTION; ADSORPTION; BINDING; AU; AG AB This note describes the results of a comparative study of the reductive desorption characteristics of alkanethiolate monolayers at single crystal Au(111) and Au(110) electrodes. The voltammetric data reveal that the reductive desorption potential is dependent on the surface gold substrate, The observed difference in potential between these two substrates is indicative of a difference in binding strength of the monolayer at different binding sites in which the gold-sulfur bonding is stronger at the Au(110) than at the Au(111) single crystal, Spectroscopic data (X-ray photoelectron and infrared reflection spectroscopies) provide additional comparisons for the monolayer structures at the two substrates. Tthese findings substantiate our recent study on the voltammetric differences between the atomically smooth surfaces of annealed Au(111) films and the micro-topographically rougher as-evaporated Au(111) films. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. RI Zhong, Chuan-Jian/D-3394-2013 NR 21 TC 118 Z9 118 U1 0 U2 18 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD JAN 30 PY 1997 VL 421 IS 1-2 BP 9 EP 13 DI 10.1016/S0022-0728(96)01025-X PG 5 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA WW942 UT WOS:A1997WW94200003 ER PT J AU Nagy, Z Hung, NC Liddell, KC Minkoff, M Leaf, GK AF Nagy, Z Hung, NC Liddell, KC Minkoff, M Leaf, GK TI Applicability of dc relaxation techniques to multi-step reactions SO JOURNAL OF ELECTROANALYTICAL CHEMISTRY LA English DT Article DE multi-step reactions; relaxation techniques; numerical modeling ID DOUBLE-PULSE METHOD; DENSITY-OVERPOTENTIAL RANGE; CHARGE-TRANSFER; ELECTRODE; KINETICS; DEPOSITION; DISSOLUTION; ADSORPTION; COPPER AB The general theory of d.c. relaxation techniques has been developed mainly for single-step electrochemical reactions and for multi-step reactions with a clearly defined rate-determining step and no intermediate accumulation either on the electrode surface or in the solution. A few workers have considered the case of multi-step reactions, but, because of the complexity of these systems, different approximations and simplifications were introduced in every treatment, limiting the general usefulness of the conclusions. Using numerical calculational methods, we have investigated the behavior of two-step (metal deposition/dissolution) reactions for potentiostatic and galvanostatic single- and double-pulse relaxation experiments. We have carried out a large number of numerical simulations using a wide range of variable values. The main purpose was to determine the conditions under which the techniques are applicable for the measurement of the rate constant of the fast and the slow step of the reaction sequence. In particular, two 'critical times' were determined: (i) the time to reach 'steady-state' conditions with the transient techniques and (ii) the time available for the determination of the fast-step kinetics at the beginning of the measuring pulse. We have succeeded in representing these conditions in graphical form as a function of parameters involving only a few (mostly known) variables. We also found that the appearance of a maximum/minimum in the relaxation curves indicates that only the fast-step kinetics can be determined. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MATH & COMP SCI,ARGONNE,IL 60439. WHEATON COLL,DEPT CHEM,WHEATON,IL 60187. WASHINGTON STATE UNIV,DEPT CHEM ENGN,PULLMAN,WA 99164. RP Nagy, Z (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 49 TC 11 Z9 11 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0022-0728 J9 J ELECTROANAL CHEM JI J. Electroanal. Chem. PD JAN 30 PY 1997 VL 421 IS 1-2 BP 33 EP 44 DI 10.1016/S0022-0728(96)04877-2 PG 12 WC Chemistry, Analytical; Electrochemistry SC Chemistry; Electrochemistry GA WW942 UT WOS:A1997WW94200007 ER PT J AU More, MB Ray, D Armentrout, PB AF More, MB Ray, D Armentrout, PB TI Cation-ether complexes in the gas phase: Bond dissociation energies of Na+(dimethyl ether)(x), x=1-4; Na+(1,2-dimethoxyethane)(x), x=1 and 2; and Na+(12-crown-4) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID COLLISION-INDUCED DISSOCIATION; DEPENDENT MASS-SPECTRA; CROWN-ETHERS; MACROCYCLE INTERACTION; ION COMPLEXATION; BINDING-ENERGIES; BREAKDOWN GRAPHS; REACTION-RATES; KINETIC DATA; ALKALI AB Bond dissociation energies of Na+[O(CH3)(2)](x), x = 1-4; Na+[(CH2OCH3)(2)](x) = 1 and 2; and Na+[c-(C2H4O)(4)] are reported. The bond dissociation energies are determined experimentally by analysis of the thresholds for collision-induced dissociation of the cation-ether complexes by xenon measured using guided ion beam mass spectrometry. In all cases, the primary and lowest energy dissociation channel observed experimentally is endothermic loss of one ligand molecule. The cross section thresholds are interpreted to yield 0 and 298 K bond dissociation energies after accounting for the effects of multiple ion-molecule collisions, internal energy of the complexes, and unimolecular decay rates. Trends in the bond dissociation energies determined by experiment and recent theoretical nb initio calculations are in good agreement. Our best experimental values, which have an average uncertainty of +/-7 kJ/mol, are lower than the theoretical values by 7 +/- 5 kJ/mol per metal-oxygen interaction. These values are compared with bond dissociation energies for the comparable lithium cation-ether complexes. This comparison reveals the thermodynamic consequences of ligand-ligand repulsion. C1 UNIV UTAH, DEPT CHEM, SALT LAKE CITY, UT 84112 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 59 TC 121 Z9 121 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 30 PY 1997 VL 101 IS 5 BP 831 EP 839 DI 10.1021/jp962851s PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL088 UT WOS:A1997WL08800013 ER PT J AU Zachariah, MR Melius, CF AF Zachariah, MR Melius, CF TI Theoretical calculation of thermochemistry for molecules in the Si-P-H system SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ENERGIES AB Ab initio molecular orbital calculations have been performed on species belonging to the Si-P-H system. These computations have been coupled to a bond additivity correction procedure to obtain heats of formation for 27 species. The Si-P single bond energy was found to be nominally about 300 kJ/mol, which is somewhat weaker than a Si-Si single bond. Multiple bond character in Si-P was found to be relatively weak. C1 SANDIA NATL LABS,LIVERMORE,CA 94551. RP Zachariah, MR (reprint author), NATL INST STAND & TECHNOL,CHEM SCI & TECHNOL LAB,GAITHERSBURG,MD 20899, USA. NR 15 TC 19 Z9 19 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 30 PY 1997 VL 101 IS 5 BP 913 EP 918 DI 10.1021/jp9617377 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL088 UT WOS:A1997WL08800024 ER PT J AU Chasman, RR Ahmad, I AF Chasman, RR Ahmad, I TI Nuclear structure at A similar to 250 and the stability of the superheavy elements SO PHYSICS LETTERS B LA English DT Article ID SINGLE-PARTICLE STATES; MASS REGION; SUPERDEFORMATION AB The implications of level spacings and level orderings in the A similar to 250 mass region vis-a-vis the stability of superheavy elements are considered. Single-particle energies in the A=250 mass region are used to fix the parameters of a Woods-Saxon potential. Evidence for the ground state assignment in Md-255 (Z=101) is presented. The potential is extrapolated to the superheavy region and the stability of superheavy elements is estimated. A critique of zero-point corrections in the Strutinsky method is presented and an alternate approach is suggested. RP Chasman, RR (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 21 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 JAN 30 PY 1997 VL 392 IS 3-4 BP 255 EP 261 DI 10.1016/S0370-2693(96)01591-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE567 UT WOS:A1997WE56700003 ER PT J AU Halyo, E Rajaraman, A Susskind, L AF Halyo, E Rajaraman, A Susskind, L TI Braneless black holes SO PHYSICS LETTERS B LA English DT Article AB It is known that the naive version of D-brane theory is inadequate to explain the black hole entropy in the limit in which the Schwarzschild radius becomes larger than all compactification radii. We present evidence that a more consistent description can be given in terms of strings with rescaled tensions. We show that the rescaling can be interpreted as a redshift of the tension of a fundamental string in the gravitational field of the black hole. An interesting connection is found between the string level number and the Rindler energy. Using this connection, we reproduce the entropies of Schwarzschild black holes in arbitrary dimensions in terms of the entropy of a single string at the Hagedorn temperature. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Halyo, E (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 9 TC 52 Z9 52 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 JAN 30 PY 1997 VL 392 IS 3-4 BP 319 EP 322 DI 10.1016/S0370-2693(96)01544-4 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE567 UT WOS:A1997WE56700014 ER PT J AU Carone, CD Murayama, H AF Carone, CD Murayama, H TI TeV right-handed neutrinos and the flavor-symmetry-improved seesaw mechanism SO PHYSICS LETTERS B LA English DT Article ID MASS; MODEL AB Horizontal flavor symmetries can drastically suppress Dirac neutrino masses well below those of the corresponding charged leptons. We show that models can be constructed where the light neutrino mass eigenvalues are small enough to give the MSW solution to the solar neutrino problem, with a right-handed neutrino scale no larger than a TeV. We present a model of this type where the right-handed neutrino scale is generated by the spontaneous breakdown of gauged U(1)(B-L), in a radiative breaking scenario driven by the right-handed neutrino Yukawa couplings. The model allows for a solution to the mu problem, and predicts the existence of a Z' boson within the reach of the LHC or the Tevatron. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Carone, CD (reprint author), UNIV CALIF BERKELEY,EARNEST ORLANDO LAWRENCE BERKELEY NATL LAB,THEORET PHYS GRP,BERKELEY,CA 94720, USA. RI Murayama, Hitoshi/A-4286-2011 NR 24 TC 4 Z9 4 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 JAN 30 PY 1997 VL 392 IS 3-4 BP 403 EP 412 DI 10.1016/S0370-2693(96)01571-7 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE567 UT WOS:A1997WE56700027 ER PT J AU Brodsky, SJ Ma, BQ AF Brodsky, SJ Ma, BQ TI Asymmetric quark/anti-quark hadronization in e(+)e(-) annihilation SO PHYSICS LETTERS B LA English DT Article ID CTEQ PARTON DISTRIBUTIONS; STRUCTURE-FUNCTION G1(X); SPIN STRUCTURE-FUNCTION; GOTTFRIED SUM; STRANGE SEA; PROTON; SCATTERING; DEUTERON; NUCLEON; CHARM AB We point out that the fragmentation of a strange quark into nucleons versus anti-nucleons is not necessarily identical D-p/s(z, Q(2)) not equal D-(p over bar)(z,Q(2)), even though the perturbative contributions from gluon splitting and evolution are p <-> (p) over bar symmetric. The observation of such asymmetries in the hadronization of strange and other heavy quarks can provide insight into the non-perturbative mechanisms underlying jet fragmentation in QCD. C1 CCAST,WORLD LAB,BEIJING 100080,PEOPLES R CHINA. ACAD SINICA,INST HIGH ENERGY PHYS,BEIJING 100039,PEOPLES R CHINA. KWANGHUA ACAD SCI,FAC NAT SCI,BEIJING 100081,PEOPLES R CHINA. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 35 TC 27 Z9 28 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 JAN 30 PY 1997 VL 392 IS 3-4 BP 452 EP 456 DI 10.1016/S0370-2693(96)01574-2 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE567 UT WOS:A1997WE56700034 ER PT J AU Eagle, AA George, GN Tiekink, ERT Young, CG AF Eagle, AA George, GN Tiekink, ERT Young, CG TI Oxotungsten(VI) chemistry of hydrotris(3,5-dimethylpyrazol-1-yl)borate: Hydroxodioxotungsten(VI), trioxotungsten(VI), and (mu-oxo)bis[dioxotungsten(VI)] complexes SO INORGANIC CHEMISTRY LA English DT Article ID MAIN-GROUP ELEMENTS; ABSORPTION FINE-STRUCTURE; X-RAY STRUCTURE; D-METAL ACIDS; M = MO; TRANSITION-METALS; MULTIPLE BONDS; BIOINORGANIC CHEMISTRY; CRYSTAL-STRUCTURES; CIS-TRIOXOTUNGSTEN(VI) COMPLEXES AB Colorless, diamagnetic, air-stable LW(VI)O(2)(OH) [L = hydrotris(3,5-dimethylpyrazol-1-yl)borate] forms when suspensions of LW(II)I(CO)(3) in dimethyl sulfoxide are heated at 100 degrees C. The complex was characterized by microanalysis, high-resolution mass spectrometry, and IR, NMR, and EXAFS spectroscopic techniques. The complex behaves as a weak acid with a pK(a) of around 4.7. Reaction of LWO(2)(OH) with NEt(4)OMe results in the formation of colorless, diamagnetic, air-stable NEt(4)[LW(VI)O(3)], which crystallizes as a tetrahydrate. Crystals of NEt(4)[LWO(3)]. 4H(2)O are monoclinic, space group P2(1)/c, with a 18.804(4) Angstrom, b = 9.901(8) Angstrom, c = 17.447(3) Angstrom, beta = 104.35(2)degrees, and V = 3146(1) Angstrom(3) for Z = 4. The structure is composed of discrete NEt(4)(+) and fac-[LWO(3)](-) ions strung in an alternating fashion along both sides of a zigzag ladder of hydrogen-bonded water molecules (directed parallel to the b axis). The distorted-octahedral [LWO(3)](-) anions, with W-O(1) = 1.740(4) Angstrom, W-O(2) = 1.759(4) Angstrom, and W-O(3) = 1.765(4) Angstrom, are hydrogen-bonded to water molecules through two oxo groups, with WO(2).. O(5)(i) = 2.666(6) Angstrom and WO(3).. O(4)(ii) = 2.693(6) Angstrom. The EXAFS spectra of NEt(4)[LWO(3)]. 4H(2)O and LWO(2)(OH) and related complexes are diagnostic of the respective trioxo or hydroxo-dioxo centers present. Colorless, diamagnetic, ah-stable [LW(VI)O(2)](2)(mu-O) is produced in a number of reactions, including the oxidation of LW(VI)O(2)(mu-O)(WO)-O-IV(CO)L and metathesis reactions involving LW(VI)I(2)Cl. The complex exhibits NMR spectra consistent with molecular C-2 symmetry and IR bands assignable to nu(WO2) (945 and 900 cm(-1)) and nu(as)(WOW) (780 cm(-1)) vibrational modes. Crystals of [LW(VI)O(2)](2)(mu-O) are monoclinic, space group C2/c, with a = 28.112-(7) Angstrom, b = 9.538(7) Angstrom, c = 15.722(8) Angstrom, beta = 115.56(2)degrees, and V = 3802(3) Angstrom(3) for Z = 4. The dinuclear structure is composed of distorted-octahedral LWO(2) units linked by the mu-oxo ligand; the terminal W=O bond lengths are identical at 1.715(5) Angstrom, while the bridging W-O(3) distance is 1.893(1) Angstrom. C1 UNIV MELBOURNE,SCH CHEM,PARKVILLE,VIC 3052,AUSTRALIA. STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. UNIV ADELAIDE,DEPT CHEM,ADELAIDE,SA 5005,AUSTRALIA. RI George, Graham/E-3290-2013 NR 69 TC 20 Z9 20 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JAN 29 PY 1997 VL 36 IS 3 BP 472 EP 479 DI 10.1021/ic9609261 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WF347 UT WOS:A1997WF34700033 ER PT J AU Zheng, YJ Ornstein, RL AF Zheng, YJ Ornstein, RL TI Mechanism of nucleophilic aromatic substitution of 1-chloro-2,4-dinitrobenzene by glutathione in the gas phase and in solution. Implications for the mode of action of glutathione S-transferases SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID 3-DIMENSIONAL STRUCTURE; DISPLACEMENT-REACTIONS; CRYSTAL-STRUCTURE; COMPLEX; RESOLUTION; ENERGIES; ANIONS; CATALYSIS; ENZYMES; SOLVENT AB The reaction mechanism of nucleophilic aromatic substitution of 1-chloro-2,4-dinitrobenzene by glutathione (as modeled by a thiomethoxide ion) in the gas phase and in solution was elucidated using nb initio molecular orbital theory in combination with a continuum solvent model at the HF/6-31G*, HF/6-31+G**, and MP2/6-31+G** levels of theory. Two ion-molecule complexes were located in the gas phase at the HF level, but only one exits at the MP2/6-31fG** level, while neither exits in aqueous solution. In aqueous solution, there is a large free energy barrier and C-S bond formation is the rate-determining step, which is in agreement with experimental observation. The calculated free energy barrier (30.2 kcal/mol) at the HF/6-31+G** level of theory seems to be in good agreement with experiment (23.8 kcal/mol), while the MP2/6-31+G** barrier is too low, indicating that the MP2/6-31+G** level of theory probably overestimates the stability of the transition state for C-S bond formation. Implications for the mode of action of glutathione S-transferases (GSTs) and a related enzyme are discussed in light of the results of the current study. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 68 TC 49 Z9 49 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 29 PY 1997 VL 119 IS 4 BP 648 EP 655 DI 10.1021/ja963177v PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA WE826 UT WOS:A1997WE82600003 ER PT J AU Telser, J Fann, YC Renner, MW Fajer, J Wang, SK Zhang, H Scott, RA Hoffman, BM AF Telser, J Fann, YC Renner, MW Fajer, J Wang, SK Zhang, H Scott, RA Hoffman, BM TI Investigation by EPR and ENDOR spectroscopy of the nickel(I) form of cofactor F-430 of Methanobacterium thermoautotrophicum and of nickel(I) octaethylisobacteriochlorin SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID COENZYME-M REDUCTASE; QUADRUPOLE RESONANCE-SPECTRA; ELECTRON-PARAMAGNETIC-RES; STRAIN-DELTA-H; METHANOGENIC BACTERIA; PENTAMETHYL ESTER; TETRAPYRROLE COFACTOR-F430; CRYSTAL-STRUCTURE; COPPER-COMPLEXES; AQUEOUS-SOLUTION AB The terminal step in methane generation by the archaeon Methanobacterium thermoautotrophicum is catalyzed by the enzyme S-methyl coenzyme M reductase (methylreductase). This enzyme contains a Ni(II) tetrapyrrole cofactor, F-430, at the active site in the resting state. A Ni(I) state ((NiF430)-F-I) has been proposed as the active form of the cofactor. Nickel isobacteriochlorins have been used to model F-430. We have investigated both (NiF430)-F-I and Ni(I)OEiBC using CW and pulsed EPR and ENDOR spectroscopy at X-band and Q-band microwave frequencies. In agreement with a previous X-band EPR and ESEEM study, at Q-band, the g tensor of (NiF430)-F-I appears axial and H-1,H-2 ENDOR of (NiF430)-F-I in H2O versus D2O solvent shows no evidence for strongly coupled, solvent-exchangeable hydrogens, and this indicates that there is no water axially coordinated to Ni(I) in contrast to the Ni(LI) resting state. Both (NiF430)-F-I and Ni(I)OEiBC give N-14 ENDOR signals arising from the four pyrrole nitrogen ligands to Ni(I). Previous EXAFS studies of Ni(I)OEiBC and Ni(I)F(430)Me(5) showed two sets of NL(I)-N distances differing by similar to 8, and in agreement with this, the N-14 ENDOR signals for both Ni(I)OEiBC and (NiF430)-F-I can be analyzed in terms of superimposed signals from two distinct types of nitrogen ligand. The difference in bond lengths determined by EXAFS is reflected in different hyperfine and quadrupole coupling constants as determined by ENDOR. Comparison of these magnetic parameters for Ni(I) complexes with those for related species, such as (CuTPP)-T-II, shows that one Set of nitrogen ligands resembles porphyrin pyrrole, while the other set is distinctively different. C1 NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. UNIV GEORGIA,CTR METALLOENZYME STUDIES,ATHENS,GA 30602. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. ROOSEVELT UNIV,CHEM PROGRAM,CHICAGO,IL 60605. OI Telser, Joshua/0000-0003-3307-2556 NR 74 TC 32 Z9 32 U1 2 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 29 PY 1997 VL 119 IS 4 BP 733 EP 743 DI 10.1021/ja9625337 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA WE826 UT WOS:A1997WE82600012 ER PT J AU Prassides, K Vavekis, K Kordatos, K Tanigaki, K Bendele, GM Stephens, PW AF Prassides, K Vavekis, K Kordatos, K Tanigaki, K Bendele, GM Stephens, PW TI Loss of cubic symmetry in low-temperature Na2RbC60 SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID FULLERIDE SUPERCONDUCTORS; K FULLERIDES; C-60; NA2CSC60; RBC60; A=CS; RB C1 NEC CORP LTD,FUNDAMENTAL RES LABS,TSUKUBA,IBARAKI 305,JAPAN. SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Prassides, K (reprint author), UNIV SUSSEX,SCH CHEM PHYS & ENVIRONM SCI,BRIGHTON BN1 9QJ,E SUSSEX,ENGLAND. RI Tanigaki, Katsumi/A-4853-2010; Kordatos, Konstantinos /E-6947-2012; Prassides, Kosmas/C-9804-2009; VAVEKIS, KONSTANTINOS/P-4349-2014 OI Tanigaki, Katsumi/0000-0003-1538-6527; VAVEKIS, KONSTANTINOS/0000-0002-1912-0964 NR 21 TC 52 Z9 52 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 29 PY 1997 VL 119 IS 4 BP 834 EP 835 DI 10.1021/ja9634076 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WE826 UT WOS:A1997WE82600027 ER PT J AU Persans, PD Deelman, PW Stokes, KL Schowalter, LJ Byrne, A Thundat, T AF Persans, PD Deelman, PW Stokes, KL Schowalter, LJ Byrne, A Thundat, T TI Optical studies of Ge islanding on Si(111) SO APPLIED PHYSICS LETTERS LA English DT Article ID RAMAN FREQUENCIES; SI ALLOYS; SUPERLATTICES; SCATTERING; DEPENDENCE; PARTICLES; SI(100); LAYERS; GROWTH AB We report an experimental study of the optical properties of island layers resulting from molecular beam epitaxial deposition of Ge on Si(111) substrates. The combination of electroreflectance spectroscopy of the E(1) transition and Raman scattering allows us to separately determine the strain and composition of the islands. For deposition at 500 degrees C a deposited layer of 1.36 nm of Ge assembles into 80 nm diameter islands 11 nm thick. The average Si impurity content in the islands is 2.5% while the average in-plane strain is 0.5%. Both strain and Si impurity content in islands decrease with increasing Ge deposition. (C) 1997 American Institute of Physics. C1 RENSSELAER POLYTECH INST,CTR INTEGRATED ELECT & ELECT MFG,TROY,NY 12180. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Persans, PD (reprint author), RENSSELAER POLYTECH INST,DEPT PHYS APPL PHYS & ASTRON,TROY,NY 12180, USA. NR 21 TC 31 Z9 32 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 27 PY 1997 VL 70 IS 4 BP 472 EP 474 DI 10.1063/1.118169 PG 3 WC Physics, Applied SC Physics GA WE457 UT WOS:A1997WE45700024 ER PT J AU Warren, WL Vanheusden, K Rodriguez, MA Seager, CH Tallant, DR Rack, PD Holloway, PH Wagner, BK Summers, CJ Yocom, PN AF Warren, WL Vanheusden, K Rodriguez, MA Seager, CH Tallant, DR Rack, PD Holloway, PH Wagner, BK Summers, CJ Yocom, PN TI Luminescence, absorption, and site symmetry of Ce activated SrGa2S4 phosphors SO APPLIED PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY AB Ce activated SrGa2S4 blue emitting phosphors were examined using electron paramagnetic resonance and x-ray diffraction to determine the local environment and oxidation state of the Ce ion. Photothermal deflection and photoluminescence spectroscopies were applied to determine absorption and emission characteristics. It is found that the majority of the Ce3+ ions substitute for the eightfold coordinated antiprismatic Sr2+ cations in the structure. Our results show that the Ce ions exhibit C-3h symmetry; this suggests that they are ninefold coordinated. This coordination may arise from a nearby S interstitial, energetically favorable because of charge compensation. To achieve this symmetry, only minor rearrangements of the eight S atoms in the antiprismatic configuration are required. (C) 1997 American Institute of Physics. C1 UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611. GEORGIA INST TECHNOL,PHOSPHOR TECHNOL CTR EXCELLENCE,ATLANTA,GA 30332. DAVID SARNOFF RES CTR,PRINCETON,NJ 08543. RP Warren, WL (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. OI Rack, Philip/0000-0002-9964-3254 NR 19 TC 14 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 27 PY 1997 VL 70 IS 4 BP 478 EP 480 DI 10.1063/1.118186 PG 3 WC Physics, Applied SC Physics GA WE457 UT WOS:A1997WE45700026 ER PT J AU Yu, J Hong, ZJ Zhou, WL Cao, GJ Xie, JF Li, XJ Li, SP Li, Z AF Yu, J Hong, ZJ Zhou, WL Cao, GJ Xie, JF Li, XJ Li, SP Li, Z TI Formation and characteristics of Pb(Zr,Ti)O-3 field-effect transistor with a SiO2 buffer layer SO APPLIED PHYSICS LETTERS LA English DT Article ID FERROELECTRIC CHARACTERIZATION; FILMS AB Ferroelectric heterostructures of Au/Pb(Zr0.52Ti0.48)O-3/SiO2/Si and Au/Pb(Zr0.52Ti0.48)O-3/Si have been fabricated by using laser ablation technique. Electrical properties of these ferroelectric field-effect transistors have been characterized through both the current vs voltage and capacitance vs voltage (C-V) measurements. The C-V characteristics of Au/Pb(Zr0.52Ti0.48)O-3/SiO2/Si heterostructures demonstrate a polarization switching behavior, showing a memory window as much as 1 V at 1 kHz. In addition, the experimental results reveal that a SiO2 buffer layer is essential for memory properties in the Au/Pb(Zr0.52Ti0.48)O-3/SiO2/Si gate structure. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Yu, J (reprint author), HUAZHONG UNIV SCI & TECHNOL,DEPT SOLID STATE ELECT,WUHAN 430074,PEOPLES R CHINA. NR 16 TC 46 Z9 58 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 27 PY 1997 VL 70 IS 4 BP 490 EP 492 DI 10.1063/1.118190 PG 3 WC Physics, Applied SC Physics GA WE457 UT WOS:A1997WE45700030 ER PT J AU Ghislotti, G Nielsen, B AsokaKumar, P Lynn, KG DiMauro, LF Comi, F Tonini, R AF Ghislotti, G Nielsen, B AsokaKumar, P Lynn, KG DiMauro, LF Comi, F Tonini, R TI Positron annihilation studies of silicon-rich SiO2 produced by high dose ion implantation SO APPLIED PHYSICS LETTERS LA English DT Article ID VISIBLE PHOTOLUMINESCENCE; ELECTRICAL-CONDUCTIVITY; POLYCRYSTALLINE SILICON; ROOM-TEMPERATURE; AMORPHOUS SIO2; FILMS; SIO2-FILMS; DEFECTS; CENTERS AB Positron annihilation spectroscopy (PAS) is used to study Si-rich SiO2 samples prepared by implantation of Si (160 keV) ions at doses in the range 3 x 10(16)-3 x 10(17) cm(-2) and subsequent thermal annealing at high temperature (up to 1100 degrees C). Samples implanted at doses higher than 5 x 10(16) cm(-2) and annealed above 1000 degrees C showed a PAS spectrum with an annihilation peak broader than the unimplanted sample. We discuss how these results are related to the process of silicon precipitation inside SiO2. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB, DEPT APPL PHYS, UPTON, NY 11973 USA. BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. UNIV MODENA, DIPARTIMENTO FIS, I-41100 MODENA, ITALY. RI Nielsen, Bent/B-7353-2009 OI Nielsen, Bent/0000-0001-7016-0040 NR 29 TC 12 Z9 12 U1 0 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 27 PY 1997 VL 70 IS 4 BP 496 EP 498 DI 10.1063/1.118315 PG 3 WC Physics, Applied SC Physics GA WE457 UT WOS:A1997WE45700032 ER PT J AU Wang, DX Kraft, GA Price, E Wood, PAD Porterfield, DW Crowe, TW AF Wang, DX Kraft, GA Price, E Wood, PAD Porterfield, DW Crowe, TW TI Noninvasive bunch length monitor for femtosecond electron bunches SO APPLIED PHYSICS LETTERS LA English DT Article ID RADIATION AB A bunch length monitor for ultrashort (90 fs to 1 ps) electron bunches using a coherent synchrotron radiation detection techniques has been developed in a collaboration between the Thomas Jefferson National accelerator Facility (Jefferson Lab) and the University of Virginia. The noninvasive, high-resolution, high-sensitivity, low-noise monitor employs a state-of-the-art ''bandpass'' GaAs Schottky whisker diode operated at room temperature. This letter presents the monitor's performance. (C) 1997 American Institute of Physics. C1 UNIV VIRGINIA,SEMICONDUCT DEVICE LAB,CHARLOTTESVILLE,VA 22903. RP Wang, DX (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606, USA. NR 9 TC 12 Z9 12 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 27 PY 1997 VL 70 IS 4 BP 529 EP 531 DI 10.1063/1.118423 PG 3 WC Physics, Applied SC Physics GA WE457 UT WOS:A1997WE45700043 ER PT J AU Williams, PT AF Williams, PT TI Relationship of distance run per week to coronary heart disease risk factors in 8283 male runners - The national runners' health study SO ARCHIVES OF INTERNAL MEDICINE LA English DT Article ID TIME PHYSICAL-ACTIVITY; HIGH-DENSITY-LIPOPROTEINS; SET-POINT THEORY; LEISURE-TIME; UNITED-STATES; COLON CANCER; WEIGHT-LOSS; VIGOROUS EXERCISE; OVERWEIGHT MEN; PLASMA-LIPIDS AB Background: Official guidelines from the Centers for Disease Control and Prevention and the American College of Sports Medicine state that every adult should accumulate 30 minutes or more of moderate-intensity physical activity on most, preferably all, days of the week. Objective: To examine the dose-response relationship between coronary heart disease (CHD) risk factors and vigorous exercise above the recommended minimum levels to assess whether further benefits accrue. Methods: Physician-supplied medical data were compared with reported distance run in a national cross; sectional survey of 8283 male recreational runners. Results: Compared with runners who ran less than 16 km (10 miles) per week, long-distance runners (greater than or equal to 80 km/wk) showed an 85% reduced prevalence of high-density lipoprotein cholesterol levels that were clinically low (<0.9 mmo/lL [(35 mg/dL]), a 2.5-fold increased prevalence of clinically defined high levels of high-density lipoprotein cholesterol (ie, greater than or equal to 1.55 mmol/L [greater than or equal to 60 mg/dL], the level thought to be protective against CHD), a nearly 50% reduction in hypertension, and more than a 50% reduction in the use of medications to lower blood pressure and plasma cholesterol levels. Estimated age-adjusted 10-year CHD risk was 30% lower in runners who averaged more than 64 km/wk than in those who averaged less than 16 km/wk (42 vs 61 events per 1000 men). Each 16-km incremental increase in weekly distance run up to 64 to 79 km/wk was associated with significant increases in high-density lipoprotein cholesterol levels and significant decreases in adiposity, triglyceride levels, the ratio of total cholesterol to high-density lipoprotein cholesterol level, and estimated CHD risk. Conclusions: Our data (1) suggest that substantial health benefits occur at exercise levels that exceed current minimum guidelines and (2) do not exhibit a point of diminishing return to the health benefits of running at any distance less than 80 km/wk. RP Williams, PT (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BLDG 934,BERKELEY,CA 94720, USA. FU NHLBI NIH HHS [HL-45652]; NIA NIH HHS [R03 AG032004, R03 AG032004-01A1] NR 47 TC 113 Z9 114 U1 1 U2 6 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 SN 0003-9926 J9 ARCH INTERN MED JI Arch. Intern. Med. PD JAN 27 PY 1997 VL 157 IS 2 BP 191 EP 198 DI 10.1001/archinte.157.2.191 PG 8 WC Medicine, General & Internal SC General & Internal Medicine GA WD844 UT WOS:A1997WD84400007 PM 9009976 ER PT J AU Tang, IN AF Tang, IN TI Thermodynamic and optical properties of mixed-salt aerosols of atmospheric importance SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AQUEOUS-SOLUTIONS; REFRACTIVE-INDEX; WATER ACTIVITIES; IONIC-SOLUTIONS; MULTICOMPONENT; ELECTROLYTES; VISIBILITY; EQUATIONS; SULFATES AB Extensive water activity, density, and refractive index data at 25 degrees C are reported for mixed-salt solutions, NaCl-KCl, NaCl-NaNO3, NaCl-Na2SO4, Na2SO4-NaNO3, and (NH4)(2)SO4-Na2SO(4) The data are obtained from hydration experiments using the single-particle levitation technique developed recently for measuring the thermodynamic and optical properties of microdroplets. These data, covering the whole concentration range from dilute solutions to high supersaturations, provide an opportunity to explore the light-scattering properties of both internal and external mixtures of the chloride, sulfate, and nitrate aerosols of atmospheric importance. It is shown that for sulfate and nitrate aerosols as solution droplets, the light-scattering properties do not differ appreciably among all mixture types and compositions, as long as the dry-salt aerosols have the same particle-size distribution. However, for mixed-salt aerosols containing NaCl, the light-scattering properties do depend upon the composition and particle-size distribution, although not so much on the mixture type. RP Tang, IN (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. NR 41 TC 201 Z9 207 U1 5 U2 28 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 JAN 27 PY 1997 VL 102 IS D2 BP 1883 EP 1893 DI 10.1029/96JD03085 PG 11 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WE650 UT WOS:A1997WE65000014 ER PT J AU Hofmann, HM Hale, GM AF Hofmann, HM Hale, GM TI Microscopic calculation of the He-4 system SO NUCLEAR PHYSICS A LA English DT Article DE He-4 system; R-matrix analysis; RGM calculation; form factors; phase shifts; reactions ID SCATTERING; NUCLEI AB We report on a consistent, microscopic calculation of the bound and scattering states in the He-4 system employing a realistic nucleon-nucleon potential in the framework of the resonating group model (RGM). We present for comparison with these microscopic RGM calculations the results from a charge-independent, Coulomb-corrected R-matrix analysis of all types of data for reactions in the A = 4 system, Comparisons are made between the phase shifts, and with a selection of measurements from each reaction, as well as between the resonance spectra obtained from both calculations. In general, the comparisons are favorable, but distinct differences are observed between the RGM calculations and some of the polarisation data. The partial-wave decomposition of the experimental data produced by the R-matrix analysis shows that these differences can be attributed to just a few S-matrix elements, for which inadequate tenser-force strength in the N-N interaction used appears to be responsible. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. RP Hofmann, HM (reprint author), UNIV ERLANGEN NURNBERG,INST THEORET PHYS 3,D-91058 ERLANGEN,GERMANY. NR 47 TC 43 Z9 43 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 JAN 27 PY 1997 VL 613 IS 1-2 BP 69 EP 106 DI 10.1016/S0375-9474(96)00418-6 PG 38 WC Physics, Nuclear SC Physics GA WF507 UT WOS:A1997WF50700005 ER PT J AU Urban, W Jones, MA Durell, JL Leddy, M Phillips, WR Smith, AG Varley, BJ Ahmad, I Morss, LR Bentaleb, M Lubkiewicz, E Schulz, N AF Urban, W Jones, MA Durell, JL Leddy, M Phillips, WR Smith, AG Varley, BJ Ahmad, I Morss, LR Bentaleb, M Lubkiewicz, E Schulz, N TI Octupole correlations in neutron-rich, even-even barium isotopes SO NUCLEAR PHYSICS A LA English DT Article DE RADIOACTIVITY Cm-248(SF); measured gamma gamma gamma-coin; linear polarization E gamma,I gamma; DCO ratios; (140,142,144,146,148) Ba deduced levels; J,pi, band structure; B(lambda) ratios ID SPONTANEOUS FISSION; GROUND-STATE; NUCLEI; DEFORMATION; CF-252; SHAPES; BA; INSTABILITY; DETECTOR; REGION AB A = 140-148 even-even barium nuclei produced in the spontaneous fission of Cm-248 were studied using the EUROGAM2 array, Spins and parities of excited levels have been firmly established from triple-gamma angular correlation and direction-polarization correlation measurements. Known band structures have been extended and new bands were found. Band-crossing phenomena have been studied, which suggest termination of an alternating-parity band by particle alignment in Ba-146 The new data for Ba-148 confirm predictions of a local decrease of electric dipole moment in Ba-146. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV STRASBOURG 1,CTR RECH NUCL,CNRS,IN2P3,F-67037 STRASBOURG,FRANCE. RP Urban, W (reprint author), UNIV MANCHESTER,DEPT PHYS & ASTRON,MANCHESTER M13 9PL,LANCS,ENGLAND. NR 46 TC 78 Z9 79 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 27 PY 1997 VL 613 IS 1-2 BP 107 EP 131 DI 10.1016/S0375-9474(96)00393-4 PG 25 WC Physics, Nuclear SC Physics GA WF507 UT WOS:A1997WF50700006 ER PT J AU Benioff, P AF Benioff, P TI Tight binding Hamiltonians and quantum turing machines SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPECTRAL PROPERTIES; COMPUTATION; SEQUENCES AB This paper extends work done to date on quantum computation by association of potentials with different types of steps. Quantum Turing machine Hamiltonians, generalized to include potentials, correspond to sums over tight binding Hamiltonians each with a different potential distribution. Which distribution applies is determined by the initial state. An example, which enumerates the integers in succession as binary strings, is analyzed. It is seen that for some initial states, the potential distributions have quasicrystalline properties and are similar to a substitution sequence. RP Benioff, P (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 27 TC 8 Z9 8 U1 1 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 JAN 27 PY 1997 VL 78 IS 4 BP 590 EP 593 DI 10.1103/PhysRevLett.78.590 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100007 ER PT J AU Bernard, C Blum, T DeTar, C Gottlieb, S Heller, UM Hetrick, JE Rummukainen, K Sugar, R Toussaint, D Wingate, M AF Bernard, C Blum, T DeTar, C Gottlieb, S Heller, UM Hetrick, JE Rummukainen, K Sugar, R Toussaint, D Wingate, M TI Which chiral symmetry is restored in high temperature quantum chromodynamics? SO PHYSICAL REVIEW LETTERS LA English DT Article ID QCD PHASE-TRANSITION AB Sigma models for the high temperature phase transition in quantum chromodynamics suggest that at high temperature the SU(N-f) x SU(N-f) chiral symmetry becomes exact, but the anomalous axial U(1) symmetry need not be restored. In numerical lattice simulations, traditional methods for detecting symmetry restoration have sought multiplets in the screening mass spectrum. However, these methods were imprecise and the results, so far, incomplete. With improved statistics and methodology, we are now able to offer evidence for a restoration of the SU(2) x SU(2) chiral symmetry just above the crossover, but not of the axial U(1) chiral symmetry. C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 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 BIELEFELD, D-33615 BIELEFELD, GERMANY. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV ARIZONA, TUCSON, AZ 85721 USA. UNIV COLORADO, BOULDER, CO 80309 USA. RP Bernard, C (reprint author), 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; DeTar, Carleton/0000-0002-0216-6771 NR 17 TC 58 Z9 58 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 JAN 27 PY 1997 VL 78 IS 4 BP 598 EP 601 DI 10.1103/PhysRevLett.78.598 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100009 ER PT J AU LaFosse, DR Devlin, M Korolija, M Lerma, F Sarantites, DG Akovali, YA Baktash, C Gross, CJ Stracener, DW Doring, J Johns, GD Tabor, SL Durham, FE Lee, IY Macchiavelli, AO Rathbun, W AF LaFosse, DR Devlin, M Korolija, M Lerma, F Sarantites, DG Akovali, YA Baktash, C Gross, CJ Stracener, DW Doring, J Johns, GD Tabor, SL Durham, FE Lee, IY Macchiavelli, AO Rathbun, W TI Interband transitions between superdeformed bands in Nb-87: Evidence for a superintruder orbital SO PHYSICAL REVIEW LETTERS LA English DT Article ID REGION; STATES; NUCLEI AB Four superdeformed bands have been observed in Nb-87. Transition quadrupole moment measurements on three of the bands confirm superdeformed shapes. Two of the bands were observed to mutually interact, and cross transitions between them have been observed. This is the first time such behavior has been observed in mass 80 superdeformed bands. Once this interaction is accounted for, a second crossing appears in one of the bands. This crossing is interpreted as evidence for the occupation of the i(13/2) superintruder orbital, making Nb-87 the lightest nucleus by far in which the shape-driving properties of this orbital can be studied. C1 OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. TULANE UNIV,DEPT PHYS,NEW ORLEANS,LA 70118. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP LaFosse, DR (reprint author), WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130, USA. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 16 TC 18 Z9 18 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 JAN 27 PY 1997 VL 78 IS 4 BP 614 EP 617 DI 10.1103/PhysRevLett.78.614 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100013 ER PT J AU Ahmad, I Austin, SM Back, BB Betts, RR Calaprice, FP Chan, KC Chishti, A Conner, C Dunford, RW Fox, JD Freedman, SJ Freer, M Gazes, SB Hallin, AL Happ, T Henderson, D Kaloskamis, NI Kashy, E Kutschera, W Last, J Lister, CJ Liu, M Maier, MR Mercer, DJ Mikolas, D Perera, PAA Rhein, MD Roa, DE Schiffer, JP Trainor, TA Wilt, P Winfield, JS Wolanski, MR Wolfs, FLH Wuosmaa, AH Xu, G Young, A Yurkon, JE AF Ahmad, I Austin, SM Back, BB Betts, RR Calaprice, FP Chan, KC Chishti, A Conner, C Dunford, RW Fox, JD Freedman, SJ Freer, M Gazes, SB Hallin, AL Happ, T Henderson, D Kaloskamis, NI Kashy, E Kutschera, W Last, J Lister, CJ Liu, M Maier, MR Mercer, DJ Mikolas, D Perera, PAA Rhein, MD Roa, DE Schiffer, JP Trainor, TA Wilt, P Winfield, JS Wolanski, MR Wolfs, FLH Wuosmaa, AH Xu, G Young, A Yurkon, JE TI Search for monoenergetic positron emission from heavy-ion collisions at Coulomb-barrier energies SO PHYSICAL REVIEW LETTERS LA English DT Article ID ATOM COLLISIONS; TH COLLISIONS; SYSTEMS; LINES; CREATION; SPECTRA; PEAKS AB Positron production in U-238 + Th-232 and U-238 + Ta-181 collisions near the Coulomb barrier has been studied. Earlier experiments reported narrow lines in the spectra of positrons, accumulated without the requirement of electrons detected in coincidence. No evidence of such structure is observed in the present data. The positron energy spectra are compared with estimates from dynamic atomic processes, and from internal pair conversion of electromagnetic transitions from the excited nuclei. C1 MICHIGAN STATE UNIV,NATL SUPERCONDUCTING CYCLOTRON LAB,E LANSING,MI 48824. MICHIGAN STATE UNIV,DEPT PHYS & ASTRON,E LANSING,MI 48824. UNIV ILLINOIS,DEPT PHYS,CHICAGO,IL 60607. PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544. YALE UNIV,WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06520. FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32306. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV BIRMINGHAM,SCH PHYS & SPACE RES,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. QUEENS UNIV,DEPT PHYS,KINGSTON,ON K7L 3N6,CANADA. GESELL SCHWERIONENFORSCH MBH,D-64291 DARMSTADT,GERMANY. UNIV ROCHESTER,NUCL STRUCT RES LAB,ROCHESTER,NY 14627. UNIV WASHINGTON,NUCL PHYS LAB,SEATTLE,WA 98195. UNIV CHICAGO,DEPT PHYS,CHICAGO,IL 60637. RP Ahmad, I (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. RI Hallin, Aksel/H-5881-2011; Freer, Martin/F-9379-2013 NR 20 TC 26 Z9 27 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 JAN 27 PY 1997 VL 78 IS 4 BP 618 EP 621 DI 10.1103/PhysRevLett.78.618 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100014 ER PT J AU Schafer, KJ Kulander, KC AF Schafer, KJ Kulander, KC TI High harmonic generation from ultrafast pump lasers SO PHYSICAL REVIEW LETTERS LA English DT Article ID PULSES; ATOMS; IONS AB Using an ultrafast pump pulse affects the spectral and temporal characteristics of high order harmonics in an unexpected and fortuitous way. Calculations of spectra for rare gases using 10-100 fs, 800 nm pulses show that as the pump pulse length decreases the highest harmonics become correspondingly shorter while their conversion efficiencies increase dramatically. Especially significant is that we find these highest harmonics have phase characteristics that allow for the possibility of compression to subfemtosecond time scales. C1 LAWRENCE LIVERMORE NATL LAB, TAMP GRP, LIVERMORE, CA 94551 USA. RP Schafer, KJ (reprint author), LOUISIANA STATE UNIV, DEPT PHYS & ASTRON, BATON ROUGE, LA 70803 USA. NR 13 TC 205 Z9 206 U1 4 U2 8 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 JAN 27 PY 1997 VL 78 IS 4 BP 638 EP 641 DI 10.1103/PhysRevLett.78.638 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100019 ER PT J AU Camassa, R Levermore, CD AF Camassa, R Levermore, CD TI Layer-mean quantities, local conservation laws, and vorticity SO PHYSICAL REVIEW LETTERS LA English DT Article AB We derive local conservation laws for layer-mean quantities in two general settings. When applied to Euler hows, the first of these settings yields well-known local conservation laws for quantities averaged between material surfaces. The second, however, leads to new local conservation laws for quantities involving the vorticity that are averaged between arbitrary surfaces. These produce the crucial vorticity conservation laws in shallow water models that admit nonhydrostatic and noncolumnar motion. Moreover, they seem to lie outside the Hamiltonian paradigm of fluid dynamics. The formalism generalizes to skew-symmetric matrix fields; applications to electromagnetism are suggested. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. UNIV ARIZONA,DEPT MATH,TUCSON,AZ 85721. RP Camassa, R (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 10 TC 8 Z9 8 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 JAN 27 PY 1997 VL 78 IS 4 BP 650 EP 653 DI 10.1103/PhysRevLett.78.650 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100022 ER PT J AU Melnichenko, YB Wignall, GD AF Melnichenko, YB Wignall, GD TI Dimensions of polymer chains in critical semidilute solutions SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGLE NEUTRON-SCATTERING; POLYSTYRENE; SOLVENT; BULK AB In this Letter we present first measurements of the radius of gyration (R-g) for polystyrene in deuterocyclohexane at the critical concentration of the polymer over a temperature range Theta greater than or equal to T greater than or equal to TC using small-angle neutron scattering and the high-concentration labeling methodology. We do not observe a reduction of R-g(T-c) at the critical temperature of phase demixing T-c as compared to R-g(Theta) in the Theta region, which indicates that the critical polymer solution cannot be considered as an ensemble of partially collapsed noninterpenetrating coils. RP Melnichenko, YB (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831, USA. OI Wignall, George/0000-0002-3876-3244 NR 23 TC 38 Z9 38 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 JAN 27 PY 1997 VL 78 IS 4 BP 686 EP 688 DI 10.1103/PhysRevLett.78.686 PG 3 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100031 ER PT J AU Vast, N Baroni, S Zerah, G Besson, JM Polian, A Grimsditch, M Chervin, JC AF Vast, N Baroni, S Zerah, G Besson, JM Polian, A Grimsditch, M Chervin, JC TI Lattice dynamics of icosahedral alpha-boron under pressure SO PHYSICAL REVIEW LETTERS LA English DT Article ID CARBIDE; SEMICONDUCTORS; VIBRATIONS; SOLIDS AB The Raman spectrum of icosahedral alpha-boron presents a very sharp peak at 525 cm(-1) that was consistently rejected from the lattice modes but is still unexplained. New Raman scattering experiments under pressure are compared with ab initio lattice dynamics calculations. The very good agreement of the mode frequencies and their pressure coefficients yields unambiguous assignment of all observed features, including the 525 cm(-1) line which is a highly harmonic librational mode of the icosahedron and mainly involves bond bending. This mode is also identified in the Raman spectrum of other icosahedral boron-rich solids. C1 ENS LYON,CECAM,F-69007 LYON,FRANCE. SISSA,I-34014 TRIESTE,ITALY. UNIV PARIS 06,CNRS,URA 782,F-75252 PARIS,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Vast, N (reprint author), CEA,CTR ETUD LIMEIL VALENTON,F-94195 VILLENEUVE ST GEO,FRANCE. RI Baroni, Stefano/F-2982-2011; Polian, Alain/E-1555-2017 OI Baroni, Stefano/0000-0002-3508-6663; Polian, Alain/0000-0003-2261-9114 NR 25 TC 107 Z9 107 U1 2 U2 14 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 27 PY 1997 VL 78 IS 4 BP 693 EP 696 DI 10.1103/PhysRevLett.78.693 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100033 ER PT J AU Fong, HF Keimer, B Milius, DL Aksay, IA AF Fong, HF Keimer, B Milius, DL Aksay, IA TI Superconductivity-induced anomalies in the spin excitation spectra of underdoped YBa2Cu3O6+x SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; MAGNETIC EXCITATIONS; STRUCTURAL ANOMALIES; ORDER-PARAMETER; DYNAMICS; SYSTEM AB Polarized and unpolarized neutron scattering have been used to determine the effect of superconductivity on the magnetic excitation spectra of YBa2Cu3O6.5 (T-c = 52 K) and YBa2Cu3O6.7 (T-c = 67 K); Pronounced enhancements of the spectral weight centered around 25 and 33 meV, respectively; are observed below T-c in both crystals, compensated predominantly by a loss of spectral weight at higher energies. The data provide important clues to the origin of the 40 meV magnetic resonance peak in YBa2Cu3O7. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544. RP Fong, HF (reprint author), PRINCETON UNIV,DEPT PHYS,PRINCETON,NJ 08544, USA. RI Aksay, Ilhan/B-9281-2008 NR 33 TC 152 Z9 152 U1 1 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 JAN 27 PY 1997 VL 78 IS 4 BP 713 EP 716 DI 10.1103/PhysRevLett.78.713 PG 4 WC Physics, Multidisciplinary SC Physics GA WV391 UT WOS:A1997WV39100038 ER PT J AU Henderson, LF Crutchfield, WY Virgona, RJ AF Henderson, LF Crutchfield, WY Virgona, RJ TI The effects of thermal conductivity and viscosity of argon on shock waves diffracting over rigid ramps SO JOURNAL OF FLUID MECHANICS LA English DT Article ID ADAPTIVE MESH REFINEMENT; HYPERBOLIC CONSERVATION-LAWS; MACH REFLECTION; TRANSITION; CRITERION; REGIONS; FLOW AB Experiments were done with strong shocks diffracting over steel ramps immersed in argon. Numerical simulations of the experiments were done by integrating the Navier-Stokes equations with a higher-order Godunov finite difference numerical scheme using isothermal non-slip boundary conditions. Adiabatic, slip boundary conditions were also studied to simulate cavity-type diffractions. Some results from an Euler numerical scheme for an ideal gas are presented for comparison, When the ramp angle theta is small enough to cause Mach reflection MR, it is found that real gas effects delay its appearance and that the trajectory of its shock triple point is initially curved; it eventually becomes straight as the MR evolves into a self-similar system. The diffraction is a regular reflection RR in the delayed state, and this is subsequently swept away by a corner signal overtaking the RR and forcing the eruption of the Mach shock. The dynamic transition occurs at, or close to, the ideal gas detachment criterion theta(e). The passage of the corner signal is marked by large oscillations in the thickness of the viscous boundary layer. With increasing theta, the delay in the onset of MR is increased as the dynamic process slows, Once selfsimilarity is established the von Neumann criterion is supported. While the evidence for the von Neumann criterion is strong, it is not conclusive because of the numerical expense. The delayed transition causes some experimental data for the trajectory to be subject to a simple parallax error. The adiabatic, slip boundary condition for self-similar flow also supports the von Neumann criterion while theta < theta(e), but the trajectory angle discontinuously changes to zero at theta(e), so that theta(e) is supported by the numerics, contrary to experiments. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, CTR COMPUTAT SCI & ENGN, BERKELEY, CA 94720 USA. TOKYO NOKO UNIV, DEPT MECH SYST ENGN, KOGANEI, TOKYO 184, JAPAN. RP Henderson, LF (reprint author), UNIV AIX MARSEILLE 1, ST JEROME CTR, MHEQ, IUSTI, F-13397 MARSEILLE, FRANCE. NR 37 TC 20 Z9 20 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 32 AVENUE OF THE AMERICAS, NEW YORK, NY 10013-2473 USA SN 0022-1120 J9 J FLUID MECH JI J. Fluid Mech. PD JAN 25 PY 1997 VL 331 BP 1 EP 36 DI 10.1017/S0022112096003850 PG 36 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WK092 UT WOS:A1997WK09200001 ER PT J AU Spencer, RH Sokolov, Y Li, HL Takenaka, B Milici, AJ Aiyar, J Nguyen, A Park, H Jap, BK Hall, JE Gutman, GA Chandy, KG AF Spencer, RH Sokolov, Y Li, HL Takenaka, B Milici, AJ Aiyar, J Nguyen, A Park, H Jap, BK Hall, JE Gutman, GA Chandy, KG TI Purification, visualization, and biophysical characterization of Kv1.3 tetramers SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID GATED K+ CHANNELS; SHAKER POTASSIUM CHANNELS; HUMAN LYMPHOCYTE-T; VACCINIA VIRUS; EXPRESSION; PROTEIN; SYSTEM; RECONSTITUTION; CHARYBDOTOXIN; INHIBITOR AB The voltage-gated K+ channel of T-lymphocytes, Kv1.3, was heterologously expressed in African Green Monkey kidney cells (CV-1) using a vaccinia virus/T7 hybrid expression system; each infected cell exhibited 10(4) to 5 x 10(5) functional channels on the cell surface. The protein, solubilized with detergent (3-[cholamidopropyl)dimethylammonio]-1-propanesulfonic acid or cholate), was purified to near-homogeneity by a single nickel-chelate chromatography step. The Kv1.3 protein expressed in vaccinia virus-infected cells and its purified counterpart are both modified by a similar to 2-kDa core-sugar moiety, most likely at a conserved N-glycosylation site in the external S1-S2 loop; absence of the sugar does not alter the biophysical properties of the channel nor does it affect expression levels. Purified Kv1.3 has an estimated size of similar to 64 kDa in denaturing SDS-polyacrylamide electrophoresis gels, consistent with its predicted size based on the amino acid sequence. By sucrose gradient sedimentation, purified Kv1.3 is seen primarily as a single peak with an approximate mass of 270 kDa, compatible with its being a homotetrameric complex of the similar to 64-kDa subunits. When reconstituted in the presence of lipid and visualized by negative-staining electron microscopy, the purified Kv1.3 protein forms small crystalline domains consisting of tetramers with dimensions of similar to 65 x 65 Angstrom. The center of each tetramer contains a stained depression which may represent the ion conduction pathway. Functional reconstitution of the Kv1.3 protein into lipid bilayers produces voltage-dependent K+-selective currents that can be blocked by two high affinity peptide antagonists of Kv1.3, margatoxin and stichodactylatoxin. C1 UNIV CALIF IRVINE,COLL MED,DEPT MICROBIOL,IRVINE,CA 92697. UNIV CALIF IRVINE,COLL MED,DEPT MOL GENET,IRVINE,CA 92697. UNIV CALIF IRVINE,COLL MED,DEPT PHYSIOL & BIOPHYS,IRVINE,CA 92697. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. PFIZER INC,PFIZER CENT RES,GROTON,CT 06340. FU NIAID NIH HHS [AI24783] NR 39 TC 46 Z9 47 U1 0 U2 2 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 24 PY 1997 VL 272 IS 4 BP 2389 EP 2395 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WD679 UT WOS:A1997WD67900056 PM 8999950 ER PT J AU Yun, T Sajonz, P Bensetiti, Z Guiochon, G AF Yun, T Sajonz, P Bensetiti, Z Guiochon, G TI Influence of the heat of adsorption on elution band profiles in nonlinear liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT Symposium on Preparative Chromatography (PREP 96) CY MAY 19-21, 1996 CL GEORGETOWN UNIV CONF CTR, WASHINGTON, DC SP Washington Chromatog Discuss Grp HO GEORGETOWN UNIV CONF CTR DE band profiles; heat of adsorption; adsorption ID AXIAL-COMPRESSION COLUMNS; PREPARATIVE CHROMATOGRAPHY AB Fundamental investigations of band profiles in nonlinear liquid chromatography have always assumed isothermal conditions. This is correct in linear, analytical chromatography, in which case the solute concentrations are very small and the influence of the heat of adsorption on the band profiles can always be neglected. However, this is no longer exact in nonlinear chromatography because the concentrations of the feed components are usually high. If the heat of adsorption is large enough, the chromatographic system cannot be considered as isothermal. The differential heat and mass balance equations are then coupled. Experimental data acquired in a typical case illustrate the effect. These data fit well to a lumped kinetic model with slow heat transfer kinetics. Further calculations suggest that the influence of the heat of adsorption on actual separations is small and could be negligible in almost all cases. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. UNIV SAARLAND,D-66123 SAARBRUCKEN,GERMANY. NR 13 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JAN 24 PY 1997 VL 760 IS 1 BP 3 EP 16 DI 10.1016/S0021-9673(96)00813-8 PG 14 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WK099 UT WOS:A1997WK09900002 ER PT J AU Yun, T Guiochon, G AF Yun, T Guiochon, G TI Visualization of the heterogeneity of column beds SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT Symposium on Preparative Chromatography (PREP 96) CY MAY 19-21, 1996 CL GEORGETOWN UNIV CONF CTR, WASHINGTON, DC SP Washington Chromatog Discuss Grp HO GEORGETOWN UNIV CONF CTR DE stationary phases, LC; packed beds ID AXIAL-COMPRESSION COLUMNS; PREPARATIVE CHROMATOGRAPHY; LIQUID-CHROMATOGRAPHY; EFFICIENCY AB Columns were packed with alternating layers of virgin Zorbax C-18 and blue colored Zorbax, treated with the dye Cibacron Blue. After consolidation of the column packing, the beds were extruded off the column, examined and photographed as they were, then cut along an axial plane, and these sections were examined and photographed. Evidence of radial heterogeneity of the distribution of the layers of the two packing materials in the bed after consolidation was observed. Friction of the bed along the column wall during consolidation was demonstrated. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. NR 17 TC 33 Z9 34 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JAN 24 PY 1997 VL 760 IS 1 BP 17 EP 24 DI 10.1016/S0021-9673(96)00815-1 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WK099 UT WOS:A1997WK09900003 ER PT J AU Jandera, P Komers, D Guiochon, G AF Jandera, P Komers, D Guiochon, G TI Effects of the gradient profile on the production rate in reversed-phase gradient elution overloaded chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT Symposium on Preparative Chromatography (PREP 96) CY MAY 19-21, 1996 CL GEORGETOWN UNIV CONF CTR, WASHINGTON, DC SP Washington Chromatog Discuss Grp HO GEORGETOWN UNIV CONF CTR DE gradient elution; preparative chromatography; band profiles; overloaded columns; phenol; cresols ID PREPARATIVE LIQUID-CHROMATOGRAPHY; MAXIMUM PRODUCTION-RATES; DESIGN PARAMETERS; PROTEIN SAMPLES; PARTICLE-SIZE; MOBILE PHASE; OPTIMIZATION; SEPARATION; SIMULATIONS; UTILITY AB Band profiles in overloaded gradient elution reversed-phase chromatography were calculated using the experimental parameters of the distribution isotherms of binary mixtures of phenol and o-cresol determined by binary frontal analysis with automatic, on-line analysis of the composition of the breakthrough curve plateaus. The dependencies of the isotherm coefficients on the composition of the mobile phase were described by three-parameter equations and used in the numerical calculations. Calculated band profiles of the sample components determined the fraction range, recovery yield and production rate necessary to obtain the required purity of the sample components with various loading factors and concentration ratios of sample components depending on the gradient profile. The production rate in preparative gradient elution HPLC depends more on the initial concentration of the stronger eluent than on the steepness of the gradient. The highest production rates can be achieved with steep gradients starting in pure water, where the sample-focusing effect is the strongest, provided feed solubility is adequate. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Jandera, P (reprint author), UNIV PARDUBICE,DEPT ANALYT CHEM,NAM LEGII 565,PARDUBICE 53210,CZECH REPUBLIC. NR 29 TC 20 Z9 20 U1 2 U2 6 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 JAN 24 PY 1997 VL 760 IS 1 BP 25 EP 39 DI 10.1016/S0021-9673(96)00811-4 PG 15 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WK099 UT WOS:A1997WK09900004 ER PT J AU Abler, JK Reddy, KR Lee, CS AF Abler, JK Reddy, KR Lee, CS TI Post-capillary affinity detection of protein microheterogeneity in capillary zone electrophoresis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE detection, electrophoresis; affinity detection; protein microheterogeneity; immunoglobulins; proteins ID ANTIGEN-ANTIBODY COMPLEXES; FLUORESCENCE DETECTION; ELECTROSTATIC POTENTIALS; CHROMATOGRAPHY; FLOW AB Post-capillary affinity detection is developed to selectively evaluate protein microheterogeneity in complex sample matrices. In this scheme, separation of protein variants is accomplished prior to affinity detection. A post-capillary reactor is constructed to allow the transfer of separated variants as well as the addition of a fluorescein-labeled analyte-binding protein into the reaction capillary. Affinity complexes are formed within the reaction capillary and monitored by laser-induced fluorescence detection. Fluorescence enhancement, upon affinity complex formation, allows selective detection of protein variants. Successful resolution of IgG Fc variants is presented and compared with affinity capillary electrophoresis techniques reported in the literature. Additionally, the effects of analyte transfer and affinity complex formation on the resolution and detection limits of IgG Fc variants are discussed. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,US DEPT ENERGY,AMES,IA 50011. NR 18 TC 21 Z9 21 U1 1 U2 1 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 JAN 24 PY 1997 VL 759 IS 1-2 BP 139 EP 147 DI 10.1016/S0021-9673(96)00766-2 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WH312 UT WOS:A1997WH31200013 ER PT J AU Niu, JE Schwarz, WHE Ruedenberg, K AF Niu, JE Schwarz, WHE Ruedenberg, K TI Electron densities and p pi-AO occupancies in pi-bonded systems SO THEOCHEM-JOURNAL OF MOLECULAR STRUCTURE LA English DT Article DE electron density; deformation density; pi-bonding ID CHEMICAL DEFORMATION DENSITIES; OCCUPATION NUMBERS; ATOMIC ORBITALS; MOLECULES; MATRICES; ENERGIES AB It is shown that a characteristic feature of pi-bonding is an accumulation of electron density around the sigma-plane. Consequently, if the molecular density is optimally simulated by the superposition of densities of independent atoms, then a very low occupancy is found for the p pi-AO in the case of an atom that is sigma- as well as pi-bonded. This is in contrast to the p pi-Mulliken population of the molecular wavefunction. The reasons for this seeming paradox are sigma-AO contraction upon bond formation, quantum mechanical interference and orbital polarization, all of which increase the density in the region near the sigma-plane. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DEPT CHEM,AMES,IA 50011. RP Niu, JE (reprint author), UNIV SIEGEN,D-57068 SIEGEN,GERMANY. NR 54 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-1280 J9 THEOCHEM-J MOL STRUC JI Theochem-J. Mol. Struct. PD JAN 24 PY 1997 VL 389 IS 1-2 BP 117 EP 128 PG 12 WC Chemistry, Physical SC Chemistry GA WK362 UT WOS:A1997WK36200011 ER PT J AU Longfellow, CA Smoliar, LA Lee, YT Lee, YR Yeh, CY Lin, SM AF Longfellow, CA Smoliar, LA Lee, YT Lee, YR Yeh, CY Lin, SM TI Competing pathways in the infrared multiphoton dissociation of hexafluoropropene SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MULTI-PHOTON DISSOCIATION; OXYGEN-ATOMS; 193.3 NM; ENERGY; CF2HCL; C3F6; 1,1,1-TRIFLUOROMETHYLCARBENE; PERFLUOROCYCLOPROPANE; TETRAFLUOROETHYLENE; PERFLUOROPROPYLENE AB The infrared multiphoton dissociation of hexafluoropropene was studied by photofragment translational spectroscopy. Two primary channels and one secondary channel were identified. The predominant primary channel produces CF3CF or C2F4 and CF2, with the heavier species undergoing further dissociation to two CF2 fragments. A number of dissociation mechanisms are proposed for the elimination of CF2, including direct cleavage of the carbon-carbon double bond. In the second primary channel, a simple bond rupture reaction produces CF3 and C2F3. As expected, the translational energy distribution for this channel peaks near zero, indicating no exit barrier is present. The activation energy for this simple bond rupture is estimated to be 100-105 kcal/mol. The branching ratio, [CF2]/[CF2], between the two primary pathways is 4.0 +/- 1.0. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. ACAD SINICA,INST ATOM & MOL SCI,TAIPEI,TAIWAN. RI Lee, Yuan-Tseh/F-7914-2012 NR 49 TC 15 Z9 15 U1 1 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 23 PY 1997 VL 101 IS 4 BP 338 EP 344 DI 10.1021/jp960653v PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL085 UT WOS:A1997WL08500003 ER PT J AU Wade, EA Clauberg, H Kim, SK Mellinger, A Moore, CB AF Wade, EA Clauberg, H Kim, SK Mellinger, A Moore, CB TI Dynamics of rotational energy release for dissociation of singlet ketene and the singlet/triplet branching ratio SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID FLEXIBLE TRANSITION-STATES; ADIABATIC CHANNEL MODEL; UNIMOLECULAR REACTIONS; PHOTO-DISSOCIATION; RATE CONSTANTS; DISTRIBUTIONS; PHOTODISSOCIATION; PHOTOFRAGMENTATION; THRESHOLD; CH2 AB The rotational energy release in the dissociation of ketene along its singlet potential energy surface is observed and compared with various statistical and dynamical theories. Rotational distributions for CO((X) over tilde (1) Sigma(+))(upsilon=1) are measured from the threshold for production of CH2((a) over tilde (1)A(1))(0,0,0) + CO((X) over tilde (1) Sigma(+))(upsilon=1) to 1720 cm(-1) above. At low energies (less than or equal to 200 cm(-1)), phase space theory (PST) matches the observed distributions. At 357 and 490 cm(-1), PST, constrained by the measured state distributions of the methylene fragment, provides a good fit. For E greater than or equal to 1107 cm(-1), the constrained PST matches the average rotational energy observed but gives distributions which are broader than observed. This contrasts with the (CH2)-C-1 fragment rotations which become progressively colder than PST as energy increases from 200 cm(-1) above the threshold. The CO(upsilon=1) rotational distributions for E greater than or equal to 357 cm(-1) contain no measurable product from triplet channel fragmentation. They can be compared with the previously determined CO(upsilon=0) rotational distributions in order to partition the yield between singlet and triplet channels and recalculate the singlet yield. This yield is found to be at the upper limit of the range previously reported. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Kim, Sang Kyu/C-1613-2011 NR 42 TC 31 Z9 31 U1 2 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 23 PY 1997 VL 101 IS 4 BP 732 EP 739 DI 10.1021/jp962131l PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL085 UT WOS:A1997WL08500062 ER PT J AU White, JC Nicholas, JB Hess, AC AF White, JC Nicholas, JB Hess, AC TI Periodic Hartree-Fock characterization of the structure and electronic properties of zeolite NaCaA SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CRYSTAL-STRUCTURE; BASIS-SETS; SI,AL-ORDERED SUPERSTRUCTURE; ABINITIO CALCULATIONS; AL COMPLEX; ABSENCE; REFINEMENT; SUBSTITUTION; DISILOXANE; SR2+ AB In this paper we present an ab initio periodic Hartree-Fock study of the electronic structure zeolite NaCaA. A model system of composition Ca8Na8Si24Al24O96 is produced, with symmetry and strict alternate ordering of silicon and aluminum. The positions of the Na and Ca cations were optimized using the RHF/STO-3G level of theory. Properties of the crystal, such as the partial charges and bond populations, the electrostatic potential, and the electric field within the zeolite cage, were calculated at the more accurate RHF/6-21G* level of theory. Results indicate that the cations are situated slightly above the 6-ring units, in agreement with recent experimental X-ray crystallographic studies. The calculated RHF/6-21G* field of the zeolite is negligible in the center of both the alpha- and beta-cage, but rises quickly close to the cation centers. C1 PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,RICHLAND,WA 99352. NR 50 TC 17 Z9 17 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 23 PY 1997 VL 101 IS 4 BP 590 EP 595 DI 10.1021/jp9623094 PG 6 WC Chemistry, Physical SC Chemistry GA WL108 UT WOS:A1997WL10800016 ER PT J AU Wu, HM Reddy, NRS Small, GJ AF Wu, HM Reddy, NRS Small, GJ TI Direct observation and hole burning of the lowest exciton level (B870) of the LH2 antenna complex of Rhodopseudomonas acidophila (strain 10050) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID PHOTOSYNTHETIC REACTION-CENTER; PRIMARY CHARGE SEPARATION; LIGHT-HARVESTING COMPLEX; POLYVINYL-ALCOHOL FILMS; RHODOBACTER-SPHAEROIDES; BACTERIOCHLOROPHYLL; BACTERIA AB Results of 4.2 K absorption and hole-burning experiments on the B850 absorption band of isolated LH2 (B800-850) complexes from Rhodopseudomonas acidophila are presented for samples that exhibited a B850 absorption band of sufficient narrowness (200 cm(-1)) to allow for direct observation of the lowest exciton level of the B850 ring of dimers as a weak but distinct shoulder at the red edge of the B850 band. This shoulder correlates perfectly with the zero-phonon hole action spectrum of B870 which has been assigned as the lowest exciton level of B850. The action spectrum reveals that the B870 band carries an inhomogeneous width of 120 +/- 10 cm(-1), is characterized by weak electron-phonon coupling, and carries 3% of the total intensity of the B850 absorption band. The B870 exciton level lies 200 cm(-1) below the B850 band maximum. Based on the X-ray structure of LH2 and under the assumption of perfect C-9 symmetry (absence of diagonal and/or off-diagonal energy disorder) for the B850 ring, the B850 maximum should be determined by the strongly allowed E(1) level of the C-9-array of bacteriochlorophyll a dimers and B870 (the A level) should be adjacent, forbidden in absorption and the lowest energy level. However, the location of the A level 200 cm(-1) below the E(1) level appears to require a coupling between the nearest bacteriochlorophyll a monomers of adjacent dimers that is larger than the coupling between the monomers of the special pair of the reaction center of Rhodobacter sphaeroides. As a result, it is concluded that diagonal and/or off-diagonal energy disorder within the B850 ring must be taken into account in order to understand B870 and the Q(y) electronic structure of B850. However, the temperature dependence (4.2-270 K) of the LH2 absorption spectrum reveals that the coupling between neighboring B850 molecules strengthens upon formation of the glycerol: H2O glass near 150 K. This is important for electronic structure calculations that utilize the room temperature structure of LH2 and low-temperature spectroscopic data. Finally, data pertaining to the pure dephasing of the B870 exciton level are presented and interpreted in terms of scattering due to imperfections in the B850 ring. C1 IOWA STATE UNIV,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 29 TC 88 Z9 90 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 23 PY 1997 VL 101 IS 4 BP 651 EP 656 DI 10.1021/jp962766k PG 6 WC Chemistry, Physical SC Chemistry GA WL108 UT WOS:A1997WL10800024 ER PT J AU Wishart, JF Sun, J Cho, M Su, C Isied, SS AF Wishart, JF Sun, J Cho, M Su, C Isied, SS TI Dependence of intramolecular electron-transfer rates on driving force, pH, and temperature in ammineruthenium-modified ferrocytochromes c SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MODIFIED CYTOCHROME-C; CYCLIC VOLTAMMETRY; AMMINE COMPLEXES; REDUCTION; PROTEINS; RUTHENIUM(II); CHEMISTRY AB Several ruthenium ammine complexes were used to modify horse-heart cytochrome c at histidine-33, creating a series of (NH3)(4)(L)Ru-Cyt c derivatives (L = H2O/OH-, ammonia, 4-ethylpyridine, 3,5-lutidine, pyridine, isonicotinamide, N-methylpyrazinium) with a wide range of driving forces for Fe-to-Ru electron transfer (-Delta G degrees = -0.125 to +0.46 eV). Electron-transfer rates and activation parameters were measured by pulse radiolysis using azide or carbonate radicals. The driving-force dependence of electron-transfer rates between redox centers of the same charge types obeys Marcus-Hush theory. The activationless rate limit for all of the ruthenium derivatives except the N-methylpyrazinium complex is 3.9 x 10(5) s(-1). Thermodynamic parameters obtained from nonisothermal differential pulse voltammetry show that the electron-transfer reactions are entropy-driven. The thermodynamic and kinetic effects of phosphate ion binding to the ruthenium center are examined. The rate of intramolecular electron transfer in (NH3)(4)(isn)Ru-III-Cyt c(II) decreases at high pH, with a midpoint at pH 9.1. C1 RUTGERS STATE UNIV,DEPT CHEM,PISCATAWAY,NJ 08855. RP Wishart, JF (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 NR 27 TC 13 Z9 13 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 23 PY 1997 VL 101 IS 4 BP 687 EP 693 DI 10.1021/jp962455+ PG 7 WC Chemistry, Physical SC Chemistry GA WL108 UT WOS:A1997WL10800029 ER PT J AU Carreras, BA AF Carreras, BA TI Plasma physics - A commotion over turbulence SO NATURE LA English DT Editorial Material ID IMPROVED CONFINEMENT; TOKAMAK RP Carreras, BA (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 12 TC 3 Z9 3 U1 1 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 23 PY 1997 VL 385 IS 6614 BP 300 EP 301 DI 10.1038/385300a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WD914 UT WOS:A1997WD91400025 ER PT J AU Banga, SS Kim, S Hubbard, K Dasgupta, T Jha, KK Patsalis, P Hauptschein, R Gamberi, B DallaFavera, R Kraemer, P Ozer, HL AF Banga, SS Kim, S Hubbard, K Dasgupta, T Jha, KK Patsalis, P Hauptschein, R Gamberi, B DallaFavera, R Kraemer, P Ozer, HL TI SEN6, a locus for SV40-mediated immortalization of human cells, maps to 6q26-27 SO ONCOGENE LA English DT Article DE immortalization; growth suppressor; SV40, SEN6; senescence ID DINUCLEOTIDE REPEAT POLYMORPHISM; HUMAN-DIPLOID FIBROBLASTS; NON-HODGKINS-LYMPHOMA; LARGE T-ANTIGEN; INDEFINITE DIVISION; CELLULAR SENESCENCE; TELOMERASE ACTIVITY; DISTINCT REGIONS; GENETIC-ANALYSIS; SIMIAN VIRUS-40 AB Normal cells show a Limited lifespan in culture and the phenotype of cellular senescence, Tumors and tumor cell lines have typically overcome this form of growth suppression and grow continuously as immortal cell lines in culture, We have exploited the DNA virus SV40 to study the mechanism by which human fibroblasts overcome senescence and become immortal, Multiple steps have now been identified, including inactivation of cellular growth suppressors through direct interaction with SV40 large T antigen and through mutation of a gene on chromosome 6 (designated SEN6), In this study, we sublocalize the site of SEN6 to 6q26-27 based on molecular genetic analysis, Twelve SV40-immortalized fibroblast cell lines share a deletion in this area based on assessment for loss of heterozygostiy (LOH) for seven informative markers on 6q, Two immortal cell lines (AR5 and HALneo) appeared to have retained separate single copies of chromosome 6 despite the fact that they are both derived from the same preimmortal SV40-transformant and should share the same mutated allele of SEN6 (Hubbard-Smith et al., 1992), Detailed analysis by polymerase chain reaction, restriction fragment length polymorphism and fluorescence in situ hybridization shows, however, that although they differ for 17 markers from the centromere to 6q26, they share AR5 derived sequences (eight markers) distal to 6q26 including the minimal deletion region, further supporting the assignment of SEN6 to this region, Since human tumors including non-Hodgkins lymphoma, mammary carcinoma and ovarian carcinoma show LOH in 6q26-27, inactivation of SEN6 may be responsible for immortalization of these tumors as well. C1 UNIV MED & DENT NEW JERSEY,NEW JERSEY MED SCH,DEPT MICROBIOL & MOL GENET,NEWARK,NJ 07103. CYPRUS INST NEUROL & GENET,DEPT CYTOGENET,NICOSIA,CYPRUS. COLUMBIA UNIV COLL PHYS & SURG,DEPT PATHOL,DIV ONCOL,NEW YORK,NY 10032. LOS ALAMOS NATL LAB,CELLULAR & MOL BIOL GRP,LOS ALAMOS,NM. FU NIA NIH HHS [AG00378, AG04821] NR 68 TC 61 Z9 61 U1 0 U2 0 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0950-9232 J9 ONCOGENE JI Oncogene PD JAN 23 PY 1997 VL 14 IS 3 BP 313 EP 321 DI 10.1038/sj.onc.1200842 PG 9 WC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity GA WD516 UT WOS:A1997WD51600007 PM 9018117 ER PT J AU Adams, AA Mitchell, GE Ormand, WE Shriner, JF AF Adams, AA Mitchell, GE Ormand, WE Shriner, JF TI Distribution of shell model reduced transition probabilities in Na-22 SO PHYSICS LETTERS B LA English DT Article ID QUANTUM SPECTRA; EIGENVECTOR COMPONENTS; MAGNETIC-FIELD; CHAOS; FLUCTUATIONS; STATISTICS; STATES; NUCLEI AB The distribution of reduced transition probabilities in Na-22 has been studied using the shell model. B(M1) and B(E2) values have been calculated for transitions among the first 25 states with each spin from J=0 to J=8, positive parity, and isospins T = 0 or T = 1. No dependence on spin, isospin, electromagnetic character, or excitation energy was found. The results were consistent with a chi(2)(v) distribution with v = 1, suggesting that Na-22 is chaotic in the energy range studied. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. TENNESSEE TECHNOL UNIV,DEPT PHYS,COOKEVILLE,TN 38505. TRIANGLE UNIV NUCL LAB,DURHAM,NC 27708. RP Adams, AA (reprint author), N CAROLINA STATE UNIV,DEPT PHYS,RALEIGH,NC 27695, USA. NR 28 TC 18 Z9 18 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 JAN 23 PY 1997 VL 392 IS 1-2 BP 1 EP 6 DI 10.1016/S0370-2693(96)01510-9 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE566 UT WOS:A1997WE56600001 ER PT J AU Nisius, D Janssens, RVF Moore, EF Fallon, P Crowell, B Lauritsen, T Hackman, G Ahmad, I Amro, H Asztalos, S Carpenter, MP Chowdhury, P Clark, RM Daly, PJ Deleplanque, MA Diamond, RM Fischer, SM Grabowski, ZW Khoo, TL Lee, IY Macchiavelli, AO Mayer, RH Stephens, FS Afanasjev, AV Ragnarsson, I AF Nisius, D Janssens, RVF Moore, EF Fallon, P Crowell, B Lauritsen, T Hackman, G Ahmad, I Amro, H Asztalos, S Carpenter, MP Chowdhury, P Clark, RM Daly, PJ Deleplanque, MA Diamond, RM Fischer, SM Grabowski, ZW Khoo, TL Lee, IY Macchiavelli, AO Mayer, RH Stephens, FS Afanasjev, AV Ragnarsson, I TI Differential lifetime measurements and configuration-dependent quadrupole moments for superdeformed bands in nuclei near Dy-152 SO PHYSICS LETTERS B LA English DT Article ID STATES AB High-precision lifetime measurements have been performed in superdeformed (SD) bands of Dy-151,Dy-152 and Tb-151 With the Doppler-shift attenuation method. Differences found in the quadrupole moments Q(0) of the yrast SD bands are understood in terms of shape polarization effects by the high-N intruder orbitals. Q(0) moments are also presented for three excited SD bands in Dy-151. Recent calculations can account for most of the observations. C1 PURDUE UNIV,W LAFAYETTE,IN 47907. N CAROLINA STATE UNIV,RALEIGH,NC 27695. TRIANGLE UNIV NUCL LAB,DURHAM,NC 27708. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RUTGERS STATE UNIV,NEW BRUNSWICK,NJ 08903. LUND INST TECHNOL,S-22100 LUND,SWEDEN. LATVIAN ACAD SCI,NUCL RES CTR,LV-2169 SALAPILS,LATVIA. UNIV MASSACHUSETTS,LOWELL,MA 01854. RP Nisius, D (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 33 TC 43 Z9 43 U1 1 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 JAN 23 PY 1997 VL 392 IS 1-2 BP 18 EP 23 DI 10.1016/S0370-2693(96)01517-1 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE566 UT WOS:A1997WE56600004 ER PT J AU Garrett, JD Robinson, JQ Foglia, AJ Jin, HQ AF Garrett, JD Robinson, JQ Foglia, AJ Jin, HQ TI Nuclear level repulsion and order vs chaos SO PHYSICS LETTERS B LA English DT Article ID SPIN IDENTICAL BANDS; NEIGHBORING ODD-A; EVEN-EVEN NUCLEI; FLUCTUATION PROPERTIES; SPACING DISTRIBUTIONS; ROTATING NUCLEI; DENSITIES AB A statistical analysis of the distribution of level spacings for states with the same angular momentum and parity is described in which the average spacing is calculated for the total ensemble of states of given I-pi in even-even, odd-even, or even-odd nuclei. Though the resulting distribution of level spacings for states of deformed nuclei with Z = 62-75 and A = 155-185 is the closest to that of a Poisson distribution yet obtained for nuclear levels, significant deviations are observed for small level spacings. Such deviations are observed independent of spin, parity, nuclear type (even-even, even-odd, or odd-even), and intrinsic nuclear excitation. Many, but not all, of the very closely-spaced levels have K-values differing by several units. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. RP Garrett, JD (reprint author), OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831, USA. NR 18 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 JAN 23 PY 1997 VL 392 IS 1-2 BP 24 EP 29 DI 10.1016/S0370-2693(96)01528-6 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE566 UT WOS:A1997WE56600005 ER PT J AU Sigl, G Lee, SJ Schramm, DN Coppi, P AF Sigl, G Lee, SJ Schramm, DN Coppi, P TI Cosmological neutrino signatures for grand unification scale physics SO PHYSICS LETTERS B LA English DT Article DE neutrino astronomy; gamma-ray astrophysics; ultra-high energy cosmic rays ID ENERGY COSMIC-RAYS; TOPOLOGICAL DEFECTS; SPECTRUM; STRINGS; RADIATION; CUTOFF; SEARCH; WELL; FLUX; EYE AB Physics beyond the standard model might imply the cosmological production of particles with grand unification scale energies. Nucleons and gamma-rays from such processes are candidates for the cosmic rays observed beyond 100 EeV (10(20) eV). Using a new particle propagation code, we calculate the neutrino fluxes predicted by such scenarios if consistency with the observed cosmic ray flux and the universal gamma-ray background at 1-10GeV is required, Flux levels detectable by proposed km(3) scale neutrino observatories are allowed by these constraints. Bounds on or detection of a neutrino flux above similar to 1 EeV would allow neutrino astronomy to probe grand unification scale physics. C1 FERMILAB NATL ACCELERATOR LAB, NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60510 USA. YALE UNIV, DEPT ASTRON, NEW HAVEN, CT 06520 USA. RP UNIV CHICAGO, ENRICO FERMI INST, DEPT ASTRON & ASTROPHYS, CHICAGO, IL 60637 USA. OI Sigl, Guenter/0000-0002-4396-645X NR 56 TC 76 Z9 76 U1 1 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 JAN 23 PY 1997 VL 392 IS 1-2 BP 129 EP 134 DI 10.1016/S0370-2693(96)01534-1 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE566 UT WOS:A1997WE56600019 ER PT J AU Burrows, PN Abraha, T Samuel, M Steinfelds, E Masuda, H AF Burrows, PN Abraha, T Samuel, M Steinfelds, E Masuda, H TI Application of Pade approximants to determination of alpha(s)(M(Z)(2)) from hadronic event shape observables in e(+)e(-) annihilation SO PHYSICS LETTERS B LA English DT Article ID ESTIMATING PERTURBATIVE COEFFICIENTS; QUANTUM-FIELD THEORY; JET CROSS-SECTIONS; E+E-ANNIHILATION; QCD CALCULATIONS; PHYSICS AB We have applied Pade approximants to perturbative QCD calculations of event shape observables in e(+)e(-) --> hadrons. We used the exact O(alpha(s)(2)) prediction and the [0/1] Pade approximant to estimate the O(alpha(s)(3)) term for 15 observables, and in each case determined alpha(s)(M(Z)(2)) from comparison with hadronic Z(0) decay data from the SLD experiment. We found the scatter among the alpha(s)(M(Z)(2)) values to be significantly reduced compared with the standard O(alpha(s)(2)) determination, implying that the Pade method provides at least a partial approximation of higher-order perturbative contributions to event shape observables. C1 OKLAHOMA STATE UNIV,DEPT PHYS,STILLWATER,OK 74078. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Burrows, PN (reprint author), MIT,NUCL SCI LAB,CAMBRIDGE,MA 02139, USA. NR 28 TC 3 Z9 3 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 JAN 23 PY 1997 VL 392 IS 1-2 BP 223 EP 228 DI 10.1016/S0370-2693(96)01582-1 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE566 UT WOS:A1997WE56600034 ER PT J AU Desai, SR Wu, HB Rohlfing, CM Wang, LS AF Desai, SR Wu, HB Rohlfing, CM Wang, LS TI A study of the structure and bonding of small aluminum oxide clusters by photoelectron spectroscopy: AlxOy- (x=1-2, y=1-5) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LYING ELECTRONIC STATES; AB-INITIO; INFRARED-SPECTRA; VIBRATIONAL FREQUENCIES; MOLECULAR-STRUCTURE; ALO; OXYGEN; IONS; ARGON; ANIONS AB The structure and bonding of aluminum oxide clusters, AlxOy (x=1-2, y=1-5), are studied with anion photoelectron spectroscopy (PES) and are compared with preliminary ab initio calculations. The spectra were obtained at four detachment photon energies: 2.33, 3.49, 4.66, and 6.42 eV. The 6.42 eV spectrum for AlO- reveals the X (2) Sigma(+) ground state and two excited states of AlO. The 6.42 eV spectrum for AlO2- also shows three states for AlO2: X (2) Pi(g) ground state and the A (2) Pi(u) and B (2) Sigma(g)(+) excited states. The spectra for Al2Oy- clusters show vibrationally resolved ground states which come from Al sp-type orbitals and also high binding energy excited states, which are mainly of oxygen 2p character. Al2O2, which has a D-2h rhombus structure, has an electron affinity (EA) of 1.88 eV and its singlet-triplet excitation energy is measured to be 0.49 eV. Much higher EAs are measured for the larger Al2Oy clusters. The PES spectra of Al2O3-, Al2O4-, and Al2O5- show very similar electronic and vibrational structure. Furthermore, the ground state vibrational frequencies of these three molecules are also similar. These observations lead us to suggest that these molecules all have a rhombuslike structure, similar to Al2O2, with the oxygen atoms sequentially attaching to the terminal aluminum atoms. The spectra are consistent with an ionic bonding view of these clusters and the vibrational frequencies are in good agreement with the theoretical results. Significant information about the structure and bonding of these small aluminum oxide clusters is obtained and discussed. (C) 1997 American Institute of Physics. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. WASHINGTON STATE UNIV, DEPT PHYS, RICHLAND, WA 99352 USA. SANDIA NATL LABS, COMBUST CHEM DEPT, LIVERMORE, CA 94551 USA. NR 74 TC 115 Z9 115 U1 2 U2 30 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1997 VL 106 IS 4 BP 1309 EP 1317 DI 10.1063/1.474085 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WE312 UT WOS:A1997WE31200002 ER PT J AU Rudolph, RN North, SW Hall, GE Sears, TJ AF Rudolph, RN North, SW Hall, GE Sears, TJ TI Diode laser measurements of CD3 quantum yields and internal energy for the dissociation of dimethyl sulfoxide-d(6) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID VIBRATIONAL-STATE DISTRIBUTIONS; 193 NM; PHOTODISSOCIATION DYNAMICS; 3-BODY DISSOCIATION; ROTATIONAL-STATE; ACETONE; PHOTOFRAGMENTATION; SPECTROSCOPY; AZOMETHANE; FRAGMENTS AB Infrared diode laser absorption spectroscopy has been used to measure the CD3 radical photoproducts formed in the 193 and 222 nm photodissociation of dimethyl sulfoxide-d(6). Quantum yields of CD3 have been determined to be 1.4+/-0.1 at 193 nm and 1.2+/-0.2 at 222 nm, compared to 2.0 for acetone-d(6) at 193 nm. An analysis of transient waveforms reflecting the vibrational relaxation and radical recombination kinetics also yields an estimate of the nascent CD3 vibrational energy content by determining the fraction of total CD3 initially produced in the vibrationless state. The nascent CD3 population in the vibrational ground state decreases in order for the following photodissociation systems: CD3I at 248 nm, DMSO-d(6) at 193 and 222 nm and acetone-d(6) at 193 nm. The DMSO results are in good agreement with recent photofragment translational spectroscopy results and support a stepwise mechanism for the dissociation of Dh?SO at both wavelengths. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Sears, Trevor/B-5990-2013; North, Simon/G-5054-2012; Hall, Gregory/D-4883-2013 OI Sears, Trevor/0000-0002-5559-0154; North, Simon/0000-0002-0795-796X; Hall, Gregory/0000-0002-8534-9783 NR 35 TC 7 Z9 7 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1997 VL 106 IS 4 BP 1346 EP 1352 DI 10.1063/1.473232 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WE312 UT WOS:A1997WE31200006 ER PT J AU Li, X Huang, YL Flesch, GD Ng, CY AF Li, X Huang, YL Flesch, GD Ng, CY TI A state-selected study of the ion-molecule reactions O+(S-4,D-2,P-2)+N-2 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TOTAL CROSS-SECTIONS; CHARGE-TRANSFER; THERMAL-ENERGY; N2; AR+(2P3/2,1/2); COEFFICIENTS; COLLISIONS; OXYGEN; BEAM; O2 AB Absolute state-selected cross sections for the reactions O+(S-4,D-2,P-2)+N-2-->N-2(+)+O,NO++N, and N++NO (and/or N++N+O) have been measured in the center-of-mass collision energy (E(c.m.)) range of 0.06-40 eV employing the differential retarding potential method and the O+(D-2) and O+(P-2) ion state-selection schemes we developed recently. Charge transfer is the overwhelming product channel for the O+(D-2)+N-2 and O+(P-2)+N-2 reactions. Contrary to the results of previous experiments, the charge transfer cross sections for O+(P-2)+N-2 are found to be 30%-100% greater than those for O+(D-2)+N-2. This observation suggests that N-2 is an excellent quenching gas for O+(D-2,P-2). While the E(c.m.) dependencies for the cross sections of NO+ from O+(S-4)+N-2 and O+(D-2)+N-2 are similar, exhibiting a broad maximum in the E(c.m.) range of 1.5-8 eV, the cross section for NO+ from O+(P-2)+N-2 is found to decrease as E(c.m.) is decreased. The N+ signal observed in the O+(S-4)+N-2 reaction is attributed to the formation of N++N+O. The pathway of O++N-2-->N++NO to generate Nt is strongly suggested as the major channel in the reactions of O+(D-2,P-2)+N-2, as evidenced by the observation of N+ well below the thermochemical thresholds of O+(D-2,P-2)+N-2-->N++N+O. (C) 1997 American Institute of Physics. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 43 TC 47 Z9 47 U1 1 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1997 VL 106 IS 4 BP 1373 EP 1381 DI 10.1063/1.474087 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WE312 UT WOS:A1997WE31200010 ER PT J AU Kim, D Doll, JD Gubernatis, JE AF Kim, D Doll, JD Gubernatis, JE TI The quantum dynamics of interfacial hydrogen: Path integral maximum entropy calculation of adsorbate vibrational line shapes for the H/Ni(111) system SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TIME-CORRELATION-FUNCTIONS; MONTE-CARLO SIMULATIONS; EMBEDDED-ATOM-METHOD; ELECTRON; SURFACE; METALS; NI AB Vibrational line shapes for a hydrogen atom on an embedded atom model (EAM) of the Ni(111) surface are extracted from path integral Monte Carlo data. Maximum entropy methods are utilized to stabilize this inversion. Our results indicate that anharmonic effects are significant, particularly for vibrational motion parallel to the surface. Unlike their normal mode analogs, calculated quantum line shapes for the EAM potential predict the correct ordering of vibrational features corresponding to parallel and perpendicular adsorbate motion. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Kim, D (reprint author), BROWN UNIV,DEPT CHEM,PROVIDENCE,RI 02912, USA. RI Kim, Dongsup/C-1612-2011 NR 20 TC 35 Z9 35 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1997 VL 106 IS 4 BP 1641 EP 1645 DI 10.1063/1.473231 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WE312 UT WOS:A1997WE31200038 ER PT J AU Williams, KR Gamelin, DR LaCroix, LB Houser, RP Tolman, WB Mulder, TC deVries, S Hedman, B Hodgson, KO Solomon, EI AF Williams, KR Gamelin, DR LaCroix, LB Houser, RP Tolman, WB Mulder, TC deVries, S Hedman, B Hodgson, KO Solomon, EI TI Influence of copper-sulfur covalency and copper-copper bonding on valence delocalization and electron transfer in the Cu-A site of cytochrome c oxidase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PARACOCCUS-DENITRIFICANS; PLASTOCYANIN; METAL; REDUCTASE; RESONANCE; PATHWAYS; BIOLOGY; COMPLEX; SPECTRA C1 STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455. TECH UNIV DELFT,DEPT MICROBIOL & ENZYMOL,NL-2628 BC DELFT,NETHERLANDS. NR 27 TC 76 Z9 76 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 22 PY 1997 VL 119 IS 3 BP 613 EP 614 DI 10.1021/ja963225b PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WD867 UT WOS:A1997WD86700022 ER PT J AU Bell, CE Eisenberg, D AF Bell, CE Eisenberg, D TI Crystal structure of nucleotide-free diphtheria toxin SO BIOCHEMISTRY LA English DT Article ID ADP-RIBOSYLATING TOXINS; REFINED STRUCTURE; PERTUSSIS TOXIN; RESOLUTION AB The crystal structure of diphtheria toxin (DT) in the absence of nucleotide (nucleotide-free DT) has been determined at 2.3 Angstrom resolution to a crystallographic R factor and free R factor of 18.2 and 28.2%, respectively. A comparison of this structure to the previously determined structures of DT in complex with adenylyl(3'-5')uridine monophosphate (ApUp) and DT in complex with nicotinamide adenine dinucleotide (NAD) reveals that there are no significant movements of the two subdomains of the catalytic (C) domain associated with dinucleotide binding. The side chains of six residues within the active-site cleft: including Tyr65, Pro38, Tyr27, Thr23, Glu148, and Tyr541 show movements of up to 3 Angstrom upon dinucleotide binding. In the structure of nucleotide-free DT, the active-site loop residues 39-47 of the C domain are well ordered and extend over the active-site cleft in approximately the same position as in the structure of DT in complex with ApUp. This is in contrast to the structure of the DT-NAD complex, in which the active-site loop is disordered. On the basis of a comparison of the nucleotide-free and NAD-bound DT structures, we suggest that the interaction of NAD with Pro38 and also possibly Tyr54 and Trp153 could disrupt the network of hydrogen bonds that stabilizes the position of the active-site loop over the active-site cleft, allowing this loop to become disordered. This may be an important step in binding of the C domain of DT to its substrate, elongation factor-2. C1 UNIV CALIF LOS ANGELES,DEPT CHEM & BIOCHEM,LOS ANGELES,CA 90095. UNIV CALIF LOS ANGELES,US DOE,LAB STRUCT BIOL & MOL MED,INST MOL BIOL,LOS ANGELES,CA 90024. FU NIGMS NIH HHS [GM31299, GM07185] NR 31 TC 29 Z9 30 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 21 PY 1997 VL 36 IS 3 BP 481 EP 488 DI 10.1021/bi962214s PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WD698 UT WOS:A1997WD69800003 PM 9012663 ER PT J AU Kim, A Bruinsma, P Chen, Y Wang, LQ Liu, J AF Kim, A Bruinsma, P Chen, Y Wang, LQ Liu, J TI Amphoteric surfactant templating route for mesoporous zirconia SO CHEMICAL COMMUNICATIONS LA English DT Article ID MOLECULAR-SIEVES; OXIDES AB An amphoteric surfactant templating route permits the synthesis of hexagonal mesophases of zirconium compounds by self-assembly of the surfactant and soluble zirconium species in aqueous solution. RP Kim, A (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 20 TC 58 Z9 60 U1 2 U2 10 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD JAN 21 PY 1997 IS 2 BP 161 EP 162 DI 10.1039/a604578b PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WG497 UT WOS:A1997WG49700009 ER PT J AU Reynolds, PA Moubaraki, B Murray, KS Cable, JW Engelhardt, LM Figgis, BN AF Reynolds, PA Moubaraki, B Murray, KS Cable, JW Engelhardt, LM Figgis, BN TI Metamagnetism in tetrachlorobis(N-phenylacetamidine)rhenium(IV) SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article ID MAGNETIC-PROPERTIES; FERROMAGNET AB Single-crystal magnetisation and polarised neutron diffraction (PND) measurements have been made for the complex cis-[ReCl4(NH=CMeNHPh)(2)]. At higher temperatures the magnetic behaviour is typical of such a rhenium-(IV) complex, with three unpaired spins (mu = 3.6 mu(B)), an almost isotropic g-tensor of 1.86(1) and a large zero-field splitting, 20, of -20(2) cm(-1). At very low temperatures the magnetisation behaviour as a function of temperature and field strength and direction indicates two magnetically ordered structural phases when H parallel to b, but only one for a and c, with T-N = 9.7(1) K. A tricritical point at T = 5.8(2) K and H = 4.40(5) T was established on the transition line in H vs. T space between the two phases when H parallel to b. This behaviour is metamagnetic. The two-dimensional form of the stronger magnetic exchange implied, with weaker interlayer interaction, can be correlated with the observed structural feature of ab planes of ReCl4 units separated by layers of phenyl rings. The PND experiment showed that about half of the spin of the system is delocalised away from the Re by covalent bonding to the Cl atoms and the amidine ligand, accompanied by considerable effects resembling spin polarisation. The magnetic space groups are P2(1)/c at low magnetic fields and Pc2(1)n at high fields along b, compared with the nuclear structural space group of Peen. C1 MONASH UNIV,DEPT CHEM,CLAYTON,VIC 3168,AUSTRALIA. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV WESTERN AUSTRALIA,DEPT CHEM,NEDLANDS,WA 6009,AUSTRALIA. RP Reynolds, PA (reprint author), AUSTRALIAN NATL UNIV,RES SCH CHEM,CANBERRA,ACT 0200,AUSTRALIA. NR 20 TC 21 Z9 21 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD JAN 21 PY 1997 IS 2 BP 263 EP 267 DI 10.1039/a603443h PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WF573 UT WOS:A1997WF57300022 ER PT J AU Lee, Y Gough, RA Kunkel, WB Leung, KN Perkins, LT Pickard, DS Sun, L Vujic, J Williams, MD Wutte, D Mondelli, AA Stengl, G AF Lee, Y Gough, RA Kunkel, WB Leung, KN Perkins, LT Pickard, DS Sun, L Vujic, J Williams, MD Wutte, D Mondelli, AA Stengl, G TI Axial energy spread measurements of an accelerated positive ion beam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID MULTICUSP AB A multicusp ion source has been designed for use in ion projection lithography. Longitudinal energy spreads of the extracted positive hydrogen ion beam have been studied using a retarding field energy analyzer, It has been found that the filament-discharge multicusp ion source can deliver a beam with an energy spread less than 3 eV which is required for the ALG-1000 machine. The multicusp ion source can also deliver the current required for the application. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. ADV LITHOG GRP,COLUMBIA,MD 21045. IONEN MIKROFABRIKAT SYST GMBH,IMS,VIENNA,AUSTRIA. UNIV CALIF BERKELEY,DEPT NUCL ENGN,BERKELEY,CA 94720. SCI APPLICAT INT CORP,MCLEAN,VA 22102. NR 6 TC 11 Z9 12 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 JAN 21 PY 1997 VL 385 IS 2 BP 204 EP 208 DI 10.1016/S0168-9002(96)00936-9 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WF943 UT WOS:A1997WF94300003 ER PT J AU Li, Z Li, CJ Verbitskaya, E Eremin, V AF Li, Z Li, CJ Verbitskaya, E Eremin, V TI Temperature-stimulated abnormal annealing of neutron-induced damage in high-resistivity silicon detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID CHARGES N-EFF; RADIATION-DAMAGE; SPECTROSCOPY AB Neutron-irradiated high-resistivity silicon detectors have been subjected to elevated temperature annealing (ETA). It has been found that both detector full depletion voltage and leakage current exhibit abnormal annealing (or ''reverse annealing'') behaviour for highly irradiated detectors: increase with ETA. Laser induced current measurements indicate a net increase of acceptor type space charges associated with the full depletion voltage increase after ETA. Current deep level transient spectroscopy (I-DLTS) and thermally stimulated current (TSC) data show that the dominant effect is the increase of a level at 0.39 eV below the conduction band (E(c) - 0.39 eV) or a level above the valence band (E(v) + 0.39 eV). Candidates tentatively identified for this level are the singly charged double vacancy (V-V-) level at E(c) - 0.39 eV, the carbon interstitial-oxygen interstitial (C-i-O-i) level at E(v) + 0.36 eV, and/or the tri-vacancy-oxygen center (V3O) at E(v) + 0.40 eV. C1 RUSSIAN ACAD SCI, AF IOFFE PHYSICOTECH INST, SU-194021 ST PETERSBURG, RUSSIA. CHINESE ACAD SCI, INST SEMICOND, BEIJING 100083, PEOPLES R CHINA. RP Li, Z (reprint author), BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RI Verbitskaya, Elena/D-1521-2014 NR 24 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 EI 1872-9576 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 1997 VL 385 IS 2 BP 321 EP 329 DI 10.1016/S0168-9002(96)01146-1 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WF943 UT WOS:A1997WF94300019 ER PT J AU Rioux, F Schmidt, MW Gordon, MS AF Rioux, F Schmidt, MW Gordon, MS TI Molecular structures for azatitanatranes SO ORGANOMETALLICS LA English DT Article ID ABINITIO; GEOMETRIES; ATRANES AB Ab initio geometry optimizations for a series of azatitanatranes, ZTi[-NR(CH2)(2)-]N-3, where Z = CH3, NH2, OH, F, and N(CH3)(2) and R = H and CH3, have been performed using a triple-xi basis set for Ti and a 6-31G(d) basis set for all other atoms. An analysis of the transannular Ti-N interaction indicates that it is significantly stronger than that found in the analogous azasilatranes. In addition there is reasonable agreement between the calculated structure and the available X-ray data for Z = N(CH3)(2) and R = CH3. Of special significance in this calculation is the fact that theory correctly predicts that the axial Ti-N bond is shorter than the equatorial Ti-N bonds. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. ST JOHNS UNIV,DEPT CHEM,COLLEGEVILLE,MN 56321. NR 19 TC 11 Z9 11 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0276-7333 J9 ORGANOMETALLICS JI Organometallics PD JAN 21 PY 1997 VL 16 IS 2 BP 158 EP 162 DI 10.1021/om960567h PG 5 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA WD812 UT WOS:A1997WD81200003 ER PT J AU Enderle, T Ha, T Ogletree, DF Chemla, DS Magowan, C Weiss, S AF Enderle, T Ha, T Ogletree, DF Chemla, DS Magowan, C Weiss, S TI Membrane specific mapping and colocalization of malarial and host skeletal proteins in the Plasmodium falciparum infected erythrocyte by dual-color near-field scanning optical microscopy SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID RESONANCE ENERGY-TRANSFER; KNOB-LIKE PROTRUSIONS; SURFACE-ANTIGEN; CELL DEFORMABILITY; PARASITE; BLOOD; CYTOADHERENCE; LOCALIZATION; ASSOCIATION; EXPRESSION AB Accurate localization of proteins within the substructure of cells and cellular organelles enables better understanding of structure-function relationships, including elucidation of protein-protein interactions. We describe the use of a near field scanning optical microscope (NSOM) to simultaneously map and detect colocalized proteins within a cell, with superresolution. The system we elected to study was that of human red blood cells invaded by the human malaria parasite Plasmodium falciparum. During intraerythrocytic growth, the parasite expresses proteins that are transported to the erythrocyte cell membrane. Association of parasite proteins with host skeletal proteins leads to modification of the erythrocyte membrane. We report on colocalization studies of parasite proteins with an erythrocyte skeletal protein. Host and parasite proteins were selectively labeled in indirect immunofluorescence antibody assays. Simultaneous dual-color excitation and detection with NSOM provided fluorescence maps together with topography of the cell membrane with subwavelength (100 nm) resolution. Colocalization studies with laser scanning confocal microscopy provided lower resolution (310 nm) fluorescence maps of cross sections through the cell. Because the two excitation colors shared the exact same near-field aperture, the two fluorescence images were acquired in perfect, pixel-by-pixel registry, free from chromatic aberrations, which contaminate laser scanning confocal microscopy measurements. Colocalization studies of the protein pairs of mature parasite-infected erythrocyte surface antigen (MESA) (parasite)/protein4.1 (host) and P. falciparum histidine rich protein (PfHRP1)(parasite)/protein4.1 (host) showed good real-space correlation for the MESA/protein4.1 pair, but relatively poor correlation for the PfHRP1/protein4.1 pair. These data imply that NSOM provides high resolution information on in situ interactions between proteins in biological membranes. This method of detecting colocalization of proteins in cellular structures may have general applicability in many areas of current biological research. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,INST MOL DESIGN,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720. RI Ha, Taekjip/B-9506-2009; Ogletree, D Frank/D-9833-2016; OI Ha, Taekjip/0000-0003-2195-6258; Ogletree, D Frank/0000-0002-8159-0182; weiss, shimon/0000-0002-0720-5426 FU NIDDK NIH HHS [DK 32094, P01 DK032094] NR 52 TC 102 Z9 106 U1 1 U2 9 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JAN 21 PY 1997 VL 94 IS 2 BP 520 EP 525 DI 10.1073/pnas.94.2.520 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WD885 UT WOS:A1997WD88500028 PM 9012816 ER PT J AU Auerbach, JM Eimerl, D Milam, D Milonni, PW AF Auerbach, JM Eimerl, D Milam, D Milonni, PW TI Perturbation theory for electric-field amplitude and phase ripple transfer in frequency doubling and tripling SO APPLIED OPTICS LA English DT Article DE frequency conversion; nonlinear optics ID GENERATION AB A theory is presented for the transfer of a perturbation of the electric field from the input to the output of a frequency converter. The transfer relationship for the field ripple is shown to depend on the plane-wave operating parameters of the converter. Predictions of the theory are shown to be in excellent agreement with full numerical simulations of doubling and tripling and experiments measuring ripple transfer in frequency doubling. (C) 1997 Optical Society of America. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Auerbach, JM (reprint author), LAWRENCE LIVERMORE NATL LAB,LASER PROGRAM,LIVERMORE,CA 94550, USA. NR 13 TC 14 Z9 21 U1 1 U2 3 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 20 PY 1997 VL 36 IS 3 BP 606 EP 612 DI 10.1364/AO.36.000606 PG 7 WC Optics SC Optics GA WD524 UT WOS:A1997WD52400012 PM 18250715 ER PT J AU Maiti, A Kaplan, T Mostoller, M Chisholm, MF Pennycook, SJ Pantelides, ST AF Maiti, A Kaplan, T Mostoller, M Chisholm, MF Pennycook, SJ Pantelides, ST TI Ordering of as impurities in a Si dislocation core SO APPLIED PHYSICS LETTERS LA English DT Article ID 90-DEGREES PARTIAL DISLOCATION; DIAMOND CUBIC-CRYSTALS; SILICON; SEMICONDUCTORS; GLIDE AB We demonstrate by ab initio calculations that segregation of As in a dislocation core in Si occurs in the form of an ordered chain of As atoms running along the dislocation pipe. All As atoms in the chain achieve threefold coordination and the segregation energy is close to 1 eV per As atom. (C) 1997 American Institute of Physics. C1 VANDERBILT UNIV,DEPT PHYS & ASTRON,NASHVILLE,TN 37235. RP Maiti, A (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. NR 20 TC 20 Z9 21 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 20 PY 1997 VL 70 IS 3 BP 336 EP 338 DI 10.1063/1.118407 PG 3 WC Physics, Applied SC Physics GA WC832 UT WOS:A1997WC83200021 ER PT J AU Smith, PM Carey, PG Sigmon, TW AF Smith, PM Carey, PG Sigmon, TW TI Excimer laser crystallization and doping of silicon films on plastic substrates SO APPLIED PHYSICS LETTERS LA English DT Article ID AMORPHOUS-SILICON AB We report the pulsed laser recrystallization and doping of thin film amorphous silicon deposited on oxide-coated polyester substrates, Although our heat-flow simulation of the laser recrystallization process indicates that the plastic is briefly subjected to temperatures above its softening point, we see no evidence of damage to the plastic or film delamination from the substrate, Film grain size is found to vary up to similar to 0.1 mu m. Electrical characteristics obtained from simple strip line resistors and thin film transistors indicate that device-quality silicon films have been produced on an inexpensive flexible plastic substrate. (C) 1997 American Institute of Physics. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. NR 12 TC 130 Z9 131 U1 5 U2 19 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 20 PY 1997 VL 70 IS 3 BP 342 EP 344 DI 10.1063/1.118409 PG 3 WC Physics, Applied SC Physics GA WC832 UT WOS:A1997WC83200023 ER PT J AU Bromley, BC Chen, KY Miller, WA AF Bromley, BC Chen, KY Miller, WA TI Line emission from an accretion disk around a rotating black hole: Toward a measurement of frame dragging SO ASTROPHYSICAL JOURNAL LA English DT Article DE accretion, accretion disks; black hole physics; galaxies, active; line, profiles relativity ID ACTIVE GALACTIC NUCLEI; ARP-102B AB Line emission from an accretion disk and a corotating hot spot about a rotating black: hole are considered for possible signatures of the frame-dragging effect. We explicitly compare integrated line profiles from a geometrically thin disk about a Schwarzschild and an extreme Kerr black hole, and show that the line profile differences are small if the inner radius of the disk is near or above the Schwarzschild stable-orbit limit of radius 6GM/c(2). However, if the inner disk radius extends below this limit, as is possible in the extreme Kerr spacetime, then differences can become significant, especially if the disk emissivity is stronger near the inner regions. We demonstrate that the first three moments of a line profile define a three-dimensional space in which the presence of material at small radii becomes quantitatively evident in broad classes of disk models. In the context of the simple, thin disk paradigm, this moment-mapping scheme suggests formally that the iron line detected by the Advanced Satellite for Cosmology and Astrophysics mission from MCG -6-30-15 (Tanaka et al.) is similar to 3 times more likely to originate from a disk about a rotating black hole than from a Schwarzschild system. A statistically significant detection of black hole rotation in this way may be achieved after only modest improvements in the quality of data. We also consider light curves and frequency shifts in line emission as a function of time for corotating hot spots In extreme Kerr and Schwarzschild geometries. The frequency-shift profile is a valuable measure of orbital parameters and might possibly be used to detect frame dragging even at radii approaching 6GM/c(2) if the inclination angle of the orbital plane is large. The light curve from a hot spot shows differences as well, although these too are pronounced only at large inclination angles. C1 LOS ALAMOS NATL LAB,DIV THEORET,THEORET ASTROPHYS GRP,LOS ALAMOS,NM 87545. NR 27 TC 78 Z9 80 U1 0 U2 2 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 20 PY 1997 VL 475 IS 1 BP 57 EP & DI 10.1086/303505 PN 1 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WD179 UT WOS:A1997WD17900007 ER PT J AU Contopanagos, H Laenen, E Sterman, G AF Contopanagos, H Laenen, E Sterman, G TI Sudakov factorization and resummation SO NUCLEAR PHYSICS B LA English DT Article DE resummation; factorization; Sudakov logarithms; exponentiation ID YAN CROSS-SECTION; PRINCIPAL-VALUE RESUMMATION; HARD ELASTIC-SCATTERING; HADRONIC EVENT SHAPES; SMALL TRANSVERSE-MOMENTUM; HIGH-ENERGY SCATTERING; TO-BACK JETS; POWER CORRECTIONS; ASYMPTOTIC-BEHAVIOR; BOSON PRODUCTION AB We present a unified derivation of the resummation of Sudakov logarithms, directly from the factorization properties of cross sections in which they occur. We rederive in this manner the well-known exponentiation of leading and non-leading logarithmic enhancements near the edge of phase space for cross sections such as deeply inelastic scattering, which are induced by an electroweak hard scattering, The relevant factorization theorems are known to hold for many such cross sections of interest, and we conjecture that they apply even more widely. For QCD hard-scattering processes, such as heavy-quark production, we show that the resummation of non-leading logarithms requires in general mixing in the space of the color tensors of the hard scattering. The exponentiation of Sudakov logarithms implies that many weighted cross sections obey particular evolution equations in momentum transfer, which streamline the computation of their Sudakov exponents. We illustrate this method with the resummation of soft-gluon enhancements of the inclusive Drell-Yan cross section, in both DIS and <(MS)over bar> factorization schemes. C1 ARGONNE NATL LAB, DIV HIGH ENERGY PHYS, ARGONNE, IL 60439 USA. CERN, DIV THEORY, CH-1211 GENEVA 23, SWITZERLAND. SUNY STONY BROOK, INST THEORET PHYS, STONY BROOK, NY 11794 USA. NR 72 TC 152 Z9 152 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN 20 PY 1997 VL 484 IS 1-2 BP 303 EP 327 DI 10.1016/S0550-3213(96)00567-6 PG 25 WC Physics, Particles & Fields SC Physics GA WF929 UT WOS:A1997WF92900015 ER PT J AU Ginocchio, JN AF Ginocchio, JN TI Pseudospin as a relativistic symmetry SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEAR-PHYSICS AB We show that pseudospin symmetry in nuclei could arise from nucleons moving in a relativistic mean field which has an attractive scalar and repulsive vector potential nearly equal in magnitude. RP Ginocchio, JN (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-5,MS B283,LOS ALAMOS,NM 87545, USA. NR 12 TC 455 Z9 469 U1 0 U2 8 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 JAN 20 PY 1997 VL 78 IS 3 BP 436 EP 439 DI 10.1103/PhysRevLett.78.436 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800010 ER PT J AU Lin, Z Tang, WM Lee, WW AF Lin, Z Tang, WM Lee, WW TI Neoclassical transport in enhanced confinement toroidal plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID REVERSED MAGNETIC SHEAR; PARTICLE SIMULATION; TOKAMAK PLASMAS AB It has recently been reported that ion thermal transport levels in enhanced confinement tokamak plasmas have been observed to fall below the ''irreducible minimum level'' predicted by standard neoclassical theory. This apparent contradiction is resolved in the present analysis by relaxing the basic neoclassical assumption that the ion's orbital excursions are much smaller than the local toroidal minor radius and the equilibrium scale lengths of the system. RP Lin, Z (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 14 TC 48 Z9 48 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 JAN 20 PY 1997 VL 78 IS 3 BP 456 EP 459 DI 10.1103/PhysRevLett.78.456 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800015 ER PT J AU Ansell, S Krishnan, S Weber, JKR Felten, JJ Nordine, PC Beno, MA Price, DL Saboungi, ML AF Ansell, S Krishnan, S Weber, JKR Felten, JJ Nordine, PC Beno, MA Price, DL Saboungi, ML TI Structure of liquid aluminum oxide SO PHYSICAL REVIEW LETTERS LA English DT Article ID NEUTRON-SCATTERING; HIGH-TEMPERATURE; X-RAY; DIFFRACTION; SIMULATION; GLASSES; RANGE; AL-27 AB The total structure factor, S(Q), and the corresponding radial distribution function, G(r), for supercooled and stable liquid aluminum oxide have been measured with x-ray synchrotron radiation. The specimens were levitated in a conical nozzle and melted with a laser, achieving temperatures in the range of 2200-2700 K. The first two peaks in S(Q) reveal intermediate-range order and dense random packing of atoms, similar to that observed in many network liquids. The first two peaks in G(r) are consistent with AlO45- structural units and show that Al2O3 undergoes a major structural rearrangement on melting with an Al coordination change from octahedral to tetrahedral. The structure does pot change appreciably with temperature in the stable and supercooled liquid. implications of these results are discussed in connection with the solidification of aluminum oxide. C1 CONTAINERLESS RES INC, EVANSTON, IL 60201 USA. RP Ansell, S (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Price, David Long/A-8468-2013; Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 25 TC 172 Z9 179 U1 5 U2 35 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 JAN 20 PY 1997 VL 78 IS 3 BP 464 EP 466 DI 10.1103/PhysRevLett.78.464 PG 3 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800017 ER PT J AU Gierer, M VanHove, MA Goldman, AI Shen, Z Chang, SL Jenks, CJ Zhang, CM Thiel, PA AF Gierer, M VanHove, MA Goldman, AI Shen, Z Chang, SL Jenks, CJ Zhang, CM Thiel, PA TI Structural analysis of the fivefold symmetric surface of the Al70Pd21Mn9 quasicrystal by low energy electron diffraction SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUASI-CRYSTAL SURFACE; ICOSAHEDRAL PHASE; SINGLE-GRAIN; AL68PD23MN9; ALLOYS; LEED AB The atomic structure of the fivefold symmetric quasicrystal surface of Al70Pd21Mn9 was investigated by means of a dynamical low energy electron-diffraction analysis. Approximations are developed to address the high structural complexity of quasicrystals, yielding average layer-by-layer structural and compositional information. A mix of several relaxed bulklike terminations is found, consistently favoring dense AL-rich outermost atomic layers. These results can be understood in terns of principles known to govern surface structures of simpler, crystalline metals. C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. RP Gierer, M (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 20 TC 125 Z9 125 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 JAN 20 PY 1997 VL 78 IS 3 BP 467 EP 470 DI 10.1103/PhysRevLett.78.467 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800018 ER PT J AU Dahmen, U Xiao, SQ Paciornik, S Johnson, E Johansen, A AF Dahmen, U Xiao, SQ Paciornik, S Johnson, E Johansen, A TI Magic-size equilibrium shapes of nanoscale Pb inclusions in Al SO PHYSICAL REVIEW LETTERS LA English DT Article ID MELTING TEMPERATURE; ELECTRON-MICROSCOPY; METALS; MATRIX; GROWTH AB We show that the equilibrium shapes of small solid Pb inclusions embedded in an Al matrix are size dependent. Using high resolution electron microscopy we have observed that small inclusions a few nanometers in size adopt equilibrium shapes with smooth {111} facets. Inclusion dimensions follow preferred sizes shown to result from the nature of the residual strain which oscillates and decreases with size. As a result, the inclusion shape is Controlled by the residual strain energy at small sizes and by the interface energy at larger sizes. C1 PUC RIO,DCMM,BR-22463 RIO JANEIRO,BRAZIL. UNIV COPENHAGEN,NIELS BOHR INST,ORSTED LAB,DK-2100 COPENHAGEN,DENMARK. RP Dahmen, U (reprint author), LBNL,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA, USA. RI Paciornik, Sidnei/E-4939-2012 OI Paciornik, Sidnei/0000-0001-6520-2007 NR 31 TC 87 Z9 87 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 20 PY 1997 VL 78 IS 3 BP 471 EP 474 DI 10.1103/PhysRevLett.78.471 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800019 ER PT J AU Zhou, SJ Beazley, DM Lomdahl, PS Holian, BL AF Zhou, SJ Beazley, DM Lomdahl, PS Holian, BL TI Large-scale molecular dynamics simulations of three-dimensional ductile failure SO PHYSICAL REVIEW LETTERS LA English DT Article ID DISLOCATION EMISSION; CRACK TIPS; NUCLEATION; FRACTURE; CLEAVAGE; BRITTLE; SILICON; LOOPS AB We have performed massively parallel 3D molecular dynamics simulations with up to 35 million atoms to investigate ductile failure, obtaining mechanistic information at the atomistic level inaccessible to experiment. We observe dislocation loops emitted from the crack front-the first time this has been seen in computer simulations. The sequence of dislocation emission events, essential for establishing an intrinsic ductility criterion,strongly depends on the crystallographic orientation of the crack front and differs strikingly from anything previously conjectured. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Zhou, SJ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 23 TC 150 Z9 153 U1 4 U2 30 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 JAN 20 PY 1997 VL 78 IS 3 BP 479 EP 482 DI 10.1103/PhysRevLett.78.479 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800021 ER PT J AU DaSilva, LB Celliers, P Collins, GW Budil, KS Holmes, NC Barbee, TW Hammel, BA Kilkenny, JD Wallace, RJ Ross, M Cauble, R Ng, A Chiu, G AF DaSilva, LB Celliers, P Collins, GW Budil, KS Holmes, NC Barbee, TW Hammel, BA Kilkenny, JD Wallace, RJ Ross, M Cauble, R Ng, A Chiu, G TI Absolute equation of state measurements on shocked liquid deuterium up to 200 GPa (2 Mbar) SO PHYSICAL REVIEW LETTERS LA English DT Article ID MOLECULAR-HYDROGEN; GIANT PLANETS; PHYSICS AB We present results of the first measurements of density, shock speed, and particle speed in liquid deuterium compressed by laser-generated shock waves to pressures from 25 to 210 Gpa (0.25 to 2.1 Mbar). The data show a significant increase in D-2 compressibility above 50 Gpa compared to a widely used equation of state model. The data strongly suggest a thermal molecular dissociation transition of the diatomic fluid into a monatomic phase. C1 UNIV BRITISH COLUMBIA,VANCOUVER,BC V5Z 1M9,CANADA. RP DaSilva, LB (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 22 TC 298 Z9 301 U1 0 U2 8 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 JAN 20 PY 1997 VL 78 IS 3 BP 483 EP 486 DI 10.1103/PhysRevLett.78.483 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800022 ER PT J AU Bao, W Broholm, C Aeppli, G Dai, P Honig, JM Metcalf, P AF Bao, W Broholm, C Aeppli, G Dai, P Honig, JM Metcalf, P TI Dramatic switching of magnetic exchange in a classic transition metal oxide: Evidence for orbital ordering SO PHYSICAL REVIEW LETTERS LA English DT Article ID CR-DOPED V2O3; INFINITE DIMENSIONS; HUBBARD-MODEL; INSULATING PHASE; NEUTRON; PURE AB Spin correlations in metallic and insulating phases of V2O3 and its derivatives are investigated using magnetic neutron scattering. Metallic samples have incommensurate spin correlations varying little with hole doping. Paramagnetic insulating samples have, spin correlations only among near neighbors. The transition from either of these phases into the low temperature insulating antiferromagnetic phase is accompanied by an abrupt change of dynamic magnetic short range, order. Our results support the idea that the transition into the antiferromagnetic insulator is also an orbital ordering transition. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. NIST,GAITHERSBURG,MD 20899. NEC CORP LTD,PRINCETON,NJ 08540. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. PURDUE UNIV,W LAFAYETTE,IN 47907. RP Bao, W (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. RI Broholm, Collin/E-8228-2011; Bao, Wei/E-9988-2011; Dai, Pengcheng /C-9171-2012 OI Broholm, Collin/0000-0002-1569-9892; Bao, Wei/0000-0002-2105-461X; Dai, Pengcheng /0000-0002-6088-3170 NR 29 TC 67 Z9 67 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 JAN 20 PY 1997 VL 78 IS 3 BP 507 EP 510 DI 10.1103/PhysRevLett.78.507 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800028 ER PT J AU Chou, FC Aharony, A Birgeneau, RJ EntinWohlman, O Greven, M Harris, AB Kastner, MA Kim, YJ Kleinberg, DS Lee, YS Zhu, Q AF Chou, FC Aharony, A Birgeneau, RJ EntinWohlman, O Greven, M Harris, AB Kastner, MA Kim, YJ Kleinberg, DS Lee, YS Zhu, Q TI Ferromagnetic moment and spin rotation transitions in tetragonal antiferromagnetic Sr2Cu3O4Cl2 SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEISENBERG-ANTIFERROMAGNET; MAGNETIC-PROPERTIES; LA2CUO4; PURE; BA2CU3O4CL2; EXCHANGE AB Sr(2)Cn(3)O(4)Cl(2) is a variant of the lamellar copper oxides, containing an extra CU2+ ion in the center of every second plaquette of the square CuO2 lattice. The two types of Cu form interpenetrating Heisenberg antiferromagnets, which order at 380 and 40 K. Magnetization measurements yield a small spontaneous ferromagnetic moment,below 380 K and two spin rotation transitions. The results are explained in detail by a pseudodipolar coupling between the two Cu lattices. A quantitative analysis of the data yields several previously unknown microscopic coupling constants, relevant to other lamellar, chain, and ladder copper oxides. C1 TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Chou, FC (reprint author), MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. RI Kim, Young-June /G-7196-2011; ENTIN, ORA/F-1114-2012; harris, A Brooks/C-8640-2013 OI Kim, Young-June /0000-0002-1172-8895; NR 20 TC 53 Z9 53 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 20 PY 1997 VL 78 IS 3 BP 535 EP 538 DI 10.1103/PhysRevLett.78.535 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800035 ER PT J AU Bao, W Axe, JD Chen, CH Cheong, SW AF Bao, W Axe, JD Chen, CH Cheong, SW TI Impact of charge ordering on magnetic correlations in perovskite (Bi,Ca)MnO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID GIANT MAGNETORESISTANCE; LA1-XSRXMNO3; TRANSITION; LATTICE; SPIN AB Single crystalline Bi1-xCaxMnO3 (0.74 less than or equal to x less than or equal to 0.82) were studied with neutron scattering, electron diffraction, and bulk magnetic measurement. We discovered dynamic ferromagnetic spin correlations at high temperatures, which are replaced by antiferromagnetic spin fluctuations at a concomitant charge ordering and structural transition. Our results indicate that thermal-activated hopping of the Jahn-Teller active e(g) electrons in these insulating materials, nevertheless, induces ferromagnetic interaction through; the double-exchange mechanism. It is the ordering of these charges which competes with the double-exchange ferromagnetic metallic state. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. RP Bao, W (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Bao, Wei/E-9988-2011; Chen, Cheng-Hsuan/F-7933-2012 OI Bao, Wei/0000-0002-2105-461X; NR 28 TC 206 Z9 211 U1 2 U2 15 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 20 PY 1997 VL 78 IS 3 BP 543 EP 546 DI 10.1103/PhysRevLett.78.543 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800037 ER PT J AU Bommeli, F Degiorgi, L Wachter, P Cho, BK Canfield, PC Chau, R Maple, MB AF Bommeli, F Degiorgi, L Wachter, P Cho, BK Canfield, PC Chau, R Maple, MB TI Optical conductivity of the superconductors LNi(2)B(2)C (L=Lu and Y) SO PHYSICAL REVIEW LETTERS LA English DT Article ID LUNI2B2C; YNI2B2C; MAGNETISM; GAP AB We have measured the optical reflectivity of LuNi2B2C and YNi2B2C compounds, and have evaluated the optical conductivity both below and above the superconducting transition temperature. The normal state optical properties suggest that these superconductors are almost in the clean limit. Our results below T-c give, however, evidence of a superconducting gap signature, and are. in agreement with a BCS singlet ground state. Our experimental findings also indicate a moderate-to-strong coupling limit for the pairing mechanism. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,INST PURE & APPL PHYS SCI,LA JOLLA,CA 92093. RP Bommeli, F (reprint author), ETH ZURICH,FESTKORPERPHYS LAB,CH-8093 ZURICH,SWITZERLAND. RI Canfield, Paul/H-2698-2014 NR 25 TC 25 Z9 25 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 JAN 20 PY 1997 VL 78 IS 3 BP 547 EP 550 DI 10.1103/PhysRevLett.78.547 PG 4 WC Physics, Multidisciplinary SC Physics GA WC798 UT WOS:A1997WC79800038 ER PT J AU Marczewski, RW AF Marczewski, RW TI Bridging the virtual valley of death for technology R&D SO SCIENTIST LA English DT Editorial Material AB The road to market: Basic research is just the first leg on new ideas' journey to the marketplace, and federal support for technology development-an essential part of successful R&D-is not sufficient to ensure that the benefits of research are fully realized, contends Richard W. Marczewski, manager of the technology and business ventures office at the National Renewable Energy Laboratory in Golden, Colo. RP Marczewski, RW (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU SCIENTIST INC PI PHILADELPHIA PA 3600 MARKET ST SUITE 450, PHILADELPHIA, PA 19104 SN 0890-3670 J9 SCIENTIST JI Scientist PD JAN 20 PY 1997 VL 11 IS 2 BP 11 EP 11 PG 1 WC Information Science & Library Science; Multidisciplinary Sciences SC Information Science & Library Science; Science & Technology - Other Topics GA WC698 UT WOS:A1997WC69800006 ER PT J AU Noceti, RP Taylor, CE DEste, JR AF Noceti, RP Taylor, CE DEste, JR TI Photocatalytic conversion of methane SO CATALYSIS TODAY LA English DT Article C1 US DOE,PITTSBURGH ENERGY TECHNOL CTR,PITTSBURGH,PA 15236. NR 6 TC 20 Z9 23 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-5861 J9 CATAL TODAY JI Catal. Today PD JAN 17 PY 1997 VL 33 IS 1-3 BP 199 EP 204 DI 10.1016/S0920-5861(96)00155-1 PG 6 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA WF262 UT WOS:A1997WF26200019 ER PT J AU Moler, EJ Kellar, SA Huff, WRA Hussain, Z Zheng, Y Hudson, EA Chen, YF Shirley, DA AF Moler, EJ Kellar, SA Huff, WRA Hussain, Z Zheng, Y Hudson, EA Chen, YF Shirley, DA TI Adsorption site and structure determination of c(2x2) N-2/Ni(100) using angle-resolved photoemission extended fine structure SO CHEMICAL PHYSICS LETTERS LA English DT Article ID NI(100); N-2; RELAXATION; ADSORBATE; SURFACE; SPECTRA; NICKEL; STATE; CO; N2 AB We have determined the atomic spatial structure of c(2 X 2) N-2/Ni(100) with angle-resolved photoemission extended fine structure using the nitrogen Is core level. The chemically shifted N Is peak intensities were summed to obtain ARPEFS curves for both nitrogen atoms in the molecule. We used a new, highly optimized program based on the Rehr-Albers scattering matrix formalism to find the adsorption site and to determine the bond lengths quantitatively. The nitrogen molecule stands upright at an atop site, with a N-Ni bond length of 2.25(1) Angstrom, a N-N bond length of 1.10(7) Angstrom, and a first layer Ni-Ni spacing of 1.76(4) Angstrom . The shake-up peak shows an identical ARPEFS diffraction pattern, confirming its intrinsic nature and supporting a previous use of this feature to decompose the peak into contributions from the chemically inequivalent nitrogen atoms. Comparison to a previously published theoretical treatment of N-N-Ni and experimental structures of analogous adsorbate systems demonstrates the importance of adsorbate-adsorbate interactions in weakly chemisorbed systems. C1 QUALOP SYST CORP,SUNNYVALE,CA 94089. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. PENN STATE UNIV,DEPT CHEM,UNIVERSITY PK,PA 16802. PENN STATE UNIV,DEPT PHYS,UNIVERSITY PK,PA 16802. RP Moler, EJ (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 94720, USA. NR 23 TC 13 Z9 13 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 JAN 17 PY 1997 VL 264 IS 5 BP 502 EP 507 DI 10.1016/S0009-2614(96)01377-2 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD782 UT WOS:A1997WD78200007 ER PT J AU Hartmann, F Horak, EM Cho, C Lupu, R Bolen, JB StetlerStevenson, MA Pfreundschuh, M Waldmann, TA Horak, ID AF Hartmann, F Horak, EM Cho, C Lupu, R Bolen, JB StetlerStevenson, MA Pfreundschuh, M Waldmann, TA Horak, ID TI Effects of the tyrosine-kinase inhibitor geldanamycin on ligand-induced Her-2/neu activation, receptor expression and proliferation of Her-2-positive malignant cell lines SO INTERNATIONAL JOURNAL OF CANCER LA English DT Article ID BENZOQUINOID ANSAMYCIN GROUP; ROUS-SARCOMA VIRUS; HERBIMYCIN-A; SIGNAL-TRANSDUCTION; HEMATOPOIETIC-CELLS; EGF RECEPTOR; TUMOR-CELLS; SRC; TRANSFORMATION; GROWTH AB Geldanamycin belongs to the family of benzoquinoid ansamycin tyrosine kinase inhibitors. We have examined its effects on Her-2/neu kinase activity, protein expression level, and proliferation of Her-2(+) malignant cells. In SK-BR-3 breast-cancer cells, short-time treatment with geldanamycin completely abrogated gp30-ligand-induced activation of Her-2 without a change of receptor-expression level. Longer treatment of intact cells with geldanamycin induced decreased steady-state Her-2 autophosphorylation activity, which correlated with reduction of Her-2 protein expression and phosphotyrosine content of several proteins. The decrease was time- and dose dependent, starting after 1 hr at 100 nM concentration and reaching completion by 24 hr. The reduction of the Her-2 protein level probably resulted from in creased degradation, since the Her-2 mRNA level remained constant. Geldanamycin effects were not specific for Her-2, since the non-receptor tyrosine-kinase fyn was inhibited equally. In contrast to these results, protein-kinase-C activity was not affected. In 3 other malignant cell lines expressing different amounts of Her-2 (SK-BR-3 > SK-OV-3 > OVCAR3 > MCF7), geldanamycin also effectively reduced Her-2-kinase activity proportionally to the decrease of protein expression. In contrast, in a [H-3]-thymidine-uptake assay, cell growth was meaningfully inhibited by geldanamycin at nanomolar concentrations only in SK-BR-3 (IC50 2nM) and MCF7 (IC50 20nM), while OVCAR3 was only moderately sensitive (IC50 2 mu M) and SK-OV-3 was clearly resistant to geldanamycin. In direct comparison with herbimycin A, another benzoquinoid ansamycin that has been more thoroughly characterized, the biologic effects of geldanamycin were more pronounced. (C) 1997 Wiley-Liss, Inc. C1 NCI,METAB BRANCH,NIH,BETHESDA,MD 20892. GEORGETOWN UNIV,MED CTR,VINCENT T LOMBARDI CANC RES CTR,WASHINGTON,DC 20007. DNAX RES INST MOL & CELLULAR BIOL INC,DEPT CELLULAR SIGNALING,PALO ALTO,CA 94304. NCI,DEPT PATHOL,NIH,BETHESDA,MD 20892. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Hartmann, F (reprint author), UNIV SAARLANDES KLINIKEN,D-66421 HOMBURG,GERMANY. NR 32 TC 47 Z9 47 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7136 J9 INT J CANCER JI Int. J. Cancer PD JAN 17 PY 1997 VL 70 IS 2 BP 221 EP 229 DI 10.1002/(SICI)1097-0215(19970117)70:2<221::AID-IJC14>3.0.CO;2-L PG 9 WC Oncology SC Oncology GA WF370 UT WOS:A1997WF37000014 PM 9009164 ER PT J AU Yun, T Bensetiti, Z Zhong, GM Guiochon, G AF Yun, T Bensetiti, Z Zhong, GM Guiochon, G TI Effect of column efficiency on the internal concentration profiles and the performance of a simulated moving-bed unit in the case of a linear isotherm SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE simulated moving-bed chromatography; column efficiency; concentration profiles ID ADSORPTION SEPARATION PROCESSES; COUNTERCURRENT; DESIGN; CHROMATOGRAPHY; ADSORBER; MIXTURE; BINARY AB Simulated moving-bed (SMB) separators have been used successfully to separate or purify continuously two components with different adsorption selectivities. A detailed understanding of their behavior is still lacking, however. A numerical solution of the equilibrium-dispersive model allows the calculation of the concentration profiles along the columns, of their progressive shifts during a cycle, of the progressive build-up of these concentration profiles in each column during the start-up period, of the concentration profiles under steady-state and of the concentration histories at the extract and raffinate ports. These profiles are illustrated and discussed. The results obtained are compared to those of the exact analytical solution of the linear, ideal model previously developed. This comparison illustrates the influence of column efficiency on the time needed to reach steady-state operation. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 27 TC 13 Z9 13 U1 0 U2 1 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 JAN 17 PY 1997 VL 758 IS 2 BP 175 EP 190 DI 10.1016/S0021-9673(96)00735-2 PG 16 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WF891 UT WOS:A1997WF89100001 ER PT J AU Baldwin, DE Hazeltine, RD Davidson, RC Porkolab, M AF Baldwin, DE Hazeltine, RD Davidson, RC Porkolab, M TI ITER forecasts SO SCIENCE LA English DT Letter C1 UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712. PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. MIT,CTR PLASMA FUS,CAMBRIDGE,MA 02139. RP Baldwin, DE (reprint author), GEN ATOM CO,FUS GRP,POB 85608,SAN DIEGO,CA 92186, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1997 VL 275 IS 5298 BP 289 EP 289 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WC873 UT WOS:A1997WC87300002 ER PT J AU Synakowski, EJ AF Synakowski, EJ TI ITER forecasts SO SCIENCE LA English DT Letter RP Synakowski, EJ (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1997 VL 275 IS 5298 BP 291 EP 292 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WC873 UT WOS:A1997WC87300006 ER PT J AU Dorland, W Kotschenreuther, M Hammett, GW AF Dorland, W Kotschenreuther, M Hammett, GW TI ITER forecasts - Response SO SCIENCE LA English DT Letter C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Dorland, W (reprint author), UNIV TEXAS,INST FUS STUDIES,AUSTIN,TX 78712, USA. RI Hammett, Gregory/D-1365-2011; Dorland, William/B-4403-2009 OI Hammett, Gregory/0000-0003-1495-6647; Dorland, William/0000-0003-2915-724X NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1997 VL 275 IS 5298 BP 292 EP 292 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WC873 UT WOS:A1997WC87300007 ER PT J AU Levin, SA Grenfell, B Hastings, A Perelson, AS AF Levin, SA Grenfell, B Hastings, A Perelson, AS TI Mathematical and computational challenges in population biology and ecosystems science SO SCIENCE LA English DT Review ID CENTER B-CELLS; HIV-INFECTION; MEASLES DYNAMICS; IMMUNE-RESPONSE; FOREST GROWTH; MODEL; CHAOS; DIVERSITY; SELECTION; AIDS AB Mathematical and computational approaches provide powerful tools in the study of problems in population biology and ecosystems science. The subject has a rich history intertwined with the development oi statistics and dynamical systems theory, but recent analytical advances, coupled with the enhanced potential of high-speed computation, have opened up new vistas and presented new challenges. Key challenges involve ways to deal with the collective dynamics of heterogeneous ensembles oi individuals, and to scale from small spatial regions to large ones. The central issues-understanding how detail at one scale makes its signature felt at other scales, and how to relate phenomena across scales-cut across scientific disciplines and go to the heart of algorithmic development of approaches to high-speed computation. Examples are given from ecology, genetics, epidemiology, and immunology. C1 UNIV CAMBRIDGE,DEPT ZOOL,CAMBRIDGE CB2 3EJ,ENGLAND. UNIV CALIF DAVIS,INST THEORET DYNAM,DIV ENVIRONM STUDIES,DAVIS,CA 95616. UNIV CALIF DAVIS,CTR POPULAT BIOL,DAVIS,CA 95616. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Levin, SA (reprint author), PRINCETON UNIV,DEPT ECOL & EVOLUT BIOL,PRINCETON,NJ 08544, USA. RI Hastings, Alan/A-7423-2008 FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI28433] NR 189 TC 244 Z9 256 U1 4 U2 43 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1997 VL 275 IS 5298 BP 334 EP 343 DI 10.1126/science.275.5298.334 PG 10 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WC873 UT WOS:A1997WC87300034 PM 8994023 ER PT J AU Pashitski, AE Gurevich, A Polyanskii, AA Larbalestier, DC Goyal, A Specht, ED Kroeger, DM DeLuca, JA Tkaczyk, JE AF Pashitski, AE Gurevich, A Polyanskii, AA Larbalestier, DC Goyal, A Specht, ED Kroeger, DM DeLuca, JA Tkaczyk, JE TI Reconstruction of current flow and imaging of current-limiting defects in polycrystalline superconducting films SO SCIENCE LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; MAGNETIC GRANULARITY; TRANSPORT CURRENTS; FLUX DISTRIBUTION; THIN-FILMS; YBA2CU3O7-DELTA; VORTICES; FIELD; OXIDE AB Magneto-optical imaging was used to visualize the inhomogeneous penetration of magnetic flux into polycrystalline TlBa2Ca2Cu3Ox films with high critical current densities, to reconstruct the local two-dimensional supercurrent flow patterns and to correlate inhomogeneities in this flow with the local crystallographic misorientation. The films have almost perfect c-axis alignment and considerable local a- and b-axis texture because the grains lend to form colonies with only slightly misaligned a and b axes, Current flows freely over these low-angle grain boundaries but is strongly reduced at intermittent colony boundaries of high misorientation, The local (<10-micrometer scale) critical current density J(c) varies widely, being up to 10 times as great as the transport J(c) (scale of similar to 1 millimeter), which itself varies by a factor of about 5 in different sections of the film, The combined experiments show that the magnitude of the transport J(c) is largely determined by a few high-angle boundaries. C1 UNIV WISCONSIN,CTR APPL SUPERCONDUCT,MADISON,WI 53706. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. GE CO,SCHENECTADY,NY 12301. RUSSIAN ACAD SCI,INST SOLID STATE PHYS,CHERNOGOLOVKA 142432,MOSCOW DIST,RUSSIA. RI Larbalestier, David/B-2277-2008; Gurevich, Alex/A-4327-2008; Specht, Eliot/A-5654-2009 OI Larbalestier, David/0000-0001-7098-7208; Gurevich, Alex/0000-0003-0759-8941; Specht, Eliot/0000-0002-3191-2163 NR 32 TC 75 Z9 75 U1 0 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 17 PY 1997 VL 275 IS 5298 BP 367 EP 369 DI 10.1126/science.275.5298.367 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WC873 UT WOS:A1997WC87300039 ER PT J AU Goldbach, A Grimsditch, M Iton, L Saboungi, ML AF Goldbach, A Grimsditch, M Iton, L Saboungi, ML TI Photoinduced formation of selenium molecules in zeolites: A resonant Raman spectroscopy study SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SPECTRA; CHAINS; CLUSTERS; ULTRAMARINE; LANTHANUM; CHANNELS; SE-3 AB After excitation of selenium encapsulated in Y-zeolite with 476 nm radiation, decomposition of the initially present semiconductor chains is observed. The fragmentation is influenced by the nature of the cations that counterbalance the negative charges of the aluminosilicate framework of the zeolite, In La3+- and Nd3+- exchanged Y-zeolite, Se-2(-) is formed upon irradiation with 476 nm laser light while Se-3 is generated in the Ca2+-exchanged form under the same conditions. Both species are identified by their resonance Raman spectra. The vibrational constants obtained for the electronic ground state of Se-3 in Ca-Y are omega(0) = 315 cm(-1) and omega(0)x(0) = 0.5 cm(-1), the respective values for Se-2(-) in La-Y are omega(0) = 329 cm(-1) and omega(0)x(0) = 0.8 cm(-1). C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RI Saboungi, Marie-Louise/C-5920-2013 OI Saboungi, Marie-Louise/0000-0002-0607-4815 NR 22 TC 26 Z9 26 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 16 PY 1997 VL 101 IS 3 BP 330 EP 334 DI 10.1021/jp962563w PG 5 WC Chemistry, Physical SC Chemistry GA WL105 UT WOS:A1997WL10500007 ER PT J AU Chou, CL AF Chou, CL TI Models of dynamical supersymmetry breaking from a SU(2k+3) gauge model SO PHYSICS LETTERS B LA English DT Article AB We investigate three classes of supersymmetric models which can be obtained by breaking the chiral SU(2k + 3) gauge theories with one antisymmetric tensor and 2k - 1 antifundamentals, For N = 3, the chiral SU(2k) x SU(3) x U(1) theories break supersymmetry by quantum deformations of the moduli spaces in the strong SU(2k) gauge coupling limit. For N = 2, it is the generalization of the SU(5) x U(2) x U(1) model mentioned in the literature. Supersymmetry is broken by carefully choosing the quark-antiquark-doublet Yukawa couplings in this model. For N = 1, this becomes the well-known model discussed in the literature. C1 STANFORD UNIV,DEPT APPL PHYS,STANFORD,CA 94309. RP Chou, CL (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 9 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 J9 PHYS LETT B JI Phys. Lett. B PD JAN 16 PY 1997 VL 391 IS 3-4 BP 329 EP 334 DI 10.1016/S0370-2693(96)01469-4 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100014 ER PT J AU Hisano, J Moroi, T Tobe, K Yamaguchi, M AF Hisano, J Moroi, T Tobe, K Yamaguchi, M TI Exact event rates of lepton flavor violating processes in supersymmetric SU(5) model SO PHYSICS LETTERS B LA English DT Article ID SOFTLY BROKEN SUPERSYMMETRY; NUMBER VIOLATION; SUPERGRAVITY; MUON AB Event rates of various lepton flavor violating processes in the minimal supersymmetric SU(5) model are calculated, using exact formulas which include Yukawa vertices of lepton-slepton-higgsino. We find subtleties in evaluating event rates due to partial cancellation between diagrams. This cancellation typically reduces the event rates significantly, and the size of the reduction strongly depends on superparticle mass spectrum. C1 UNIV TOKYO,DEPT PHYS,TOKYO 113,JAPAN. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. TOHOKU UNIV,DEPT PHYS,SENDAI,MIYAGI 98077,JAPAN. TECH UNIV MUNICH,DEPT PHYS,INST THEORET PHYS,D-85747 GARCHING,GERMANY. NR 18 TC 137 Z9 137 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 JAN 16 PY 1997 VL 391 IS 3-4 BP 341 EP 350 DI 10.1016/S0370-2693(96)01473-6 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100016 ER PT J AU Sochen, N AF Sochen, N TI Integrable generalized principal chiral models SO PHYSICS LETTERS B LA English DT Article ID 2 DIMENSIONS; ALGEBRAS; FIELD AB We study 2D non-linear sigma models on a group manifold with a special form of the metric. We address the question of integrability for this special class of sigma models. We derive two algebraic conditions for the metric on the group manifold. Each solution of these conditions defines an integrable model. Although the algebraic system is overdetermined in general, we give two examples of solutions. We find the Lax field for these models and calculate their Poisson brackets. We also obtain the renormalization group (RG) equations, to first order, for the generic model. We solve the RG equations for the examples we have and show that they are integrable along the RG flow. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP Sochen, N (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 15 TC 13 Z9 13 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 JAN 16 PY 1997 VL 391 IS 3-4 BP 374 EP 380 DI 10.1016/S0370-2693(96)01468-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100021 ER PT J AU He, XG Soni, A AF He, XG Soni, A TI Color-octet contribution and direct CP violation in B->psi(psi')X SO PHYSICS LETTERS B LA English DT Article ID B-DECAYS; HEAVY QUARKONIUM; FRAGMENTATION; ASYMMETRIES; QCD AB We study color-actet contribution to B --> psi(psi')X. When this contribution is included, the theoretical predictions for the branching ratios become in much better agreement with the experiment. This mechanism also enhances the partial rate asymmetries by about a factor of five. The inclusive psi(psi') resulting from b --> d + gluon can have asymmetry around a few percent whereas those from b --> s + gluon has it around 4 x 10(-4). The asymmetry in the former modes should be observable, to a significance of 3 sigma, with about (1-10) x 10(8)B mesons. C1 BROOKHAVEN NATL LAB,THEORY GRP,UPTON,NY 11973. RP He, XG (reprint author), UNIV MELBOURNE,SCH PHYS,PARKVILLE,VIC 3052,AUSTRALIA. RI He, Xiao-Gang/C-8894-2013; He, Xiao-Gang/P-2242-2015 NR 25 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 16 PY 1997 VL 391 IS 3-4 BP 456 EP 460 DI 10.1016/S0370-2693(96)01466-9 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100033 ER PT J AU Arbex, N Ornik, U Plumer, M Schlei, BR Weiner, RM AF Arbex, N Ornik, U Plumer, M Schlei, BR Weiner, RM TI pi(-)/pi(+) ratio in heavy ion collisions: Coulomb effect or chemical equilibration? SO PHYSICS LETTERS B LA English DT Article ID STRANGE PARTICLE-PRODUCTION; RELATIVISTIC HYDRODYNAMICS; INTERFEROMETRY AB We calculate the pi(-)/pi(+) ratio for Pb + Pb at CERN/SPS energies and for Au + Au at BNL/AGS energies using a (3 + 1) dimensional hydrodynamical model. Without consideration of Coulomb effect an enhancement of this ratio at low mi is found compatible with that observed in these experiments. Our calculations are based on previous (3 + 1) dimensional hydrodynamical simulations (HYLANDER), which described many other aspects of experimental data. In this model the observed enhancement is a consequence of baryon and strangeness conservation and of chemical equilibration of the system and is caused by the decay of produced hyperons, which leads to a difference in the total number of positive and negative pions as well. Based on the same approach, we also present results for the pi(-)/pi(+) ratio for S + S (CERN/SPS) collisions, where we find a similar effect. The absence of the enhancement of the pi(-)/pi(+) ratio in the S + S data presented by the NA44 Collaboration, if confirmed, could indicate that chemical equilibration has not yet been established in this reaction. C1 SOULTEK INTERNET SERV,MARBURG,GERMANY. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV PARIS 11,PHYS THEOR & HAUTES ENERGIES LAB,ORSAY,FRANCE. RP Arbex, N (reprint author), UNIV MARBURG,DEPT PHYS,D-35032 MARBURG,GERMANY. NR 17 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 J9 PHYS LETT B JI Phys. Lett. B PD JAN 16 PY 1997 VL 391 IS 3-4 BP 465 EP 468 DI 10.1016/S0370-2693(96)01289-0 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100035 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R DeBoeck, H Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A VanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Opitz, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R DeBoeck, H Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gougas, A Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A VanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Opitz, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK Pascale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, JB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Search for neutral B meson decays to two charged leptons SO PHYSICS LETTERS B LA English DT Article ID L3 EXPERIMENT; B->MU+MU AB The decays B-d(0), B-s(0)--> e(+)e(-), mu(+)mu(-), e(+/-)mu(-/+) are LEP I data sample collected by the L3 detector. No signals are observed, therefore upper limits at the 90% (95%) confidence levels are set on the following branching fractions: Br(B-d(0) --> e(+)e(-)) < 1.4(1.8) x 10(-5); Br(B-s(0) --> e(+)e(-)) < 5.4(7.0) x 10(-5); Br(B-d(0) --> mu(+)mu(-)) < 1.0(1.4) x 10(-5); Br(B-s(0) -->mu(+)mu(-)) < 3.8(5.1) x 10(-5); Br(B-d(0) --> e(+/-)mu(-/+)) < 1.6(2.0) x 10(-5); Br(B-s(0) --> e(+/-)mu(-/+)) < 4.1(5.3) x 10(-5); The results for B-s(0) --> e(+)e(-) and B-s(0) --> e(+/-)mu(-/+) are the first limits set on these decay models. C1 RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, LAPP, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. UNIV FLORENCE, I-50125 FLORENCE, ITALY. WORLD LAB, FBLIA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. CHINESE UNIV SCI & TECHNOL, HEFEI 230029, ANHUI, PEOPLES R CHINA. SEFT, RES INST HIGH ENERGY PHYS, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. UNIV LECCE, I-73100 LECCE, ITALY. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, INST PHYS NUCL LYON, IN2P3, CNRS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. INST PHYS NUCL, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATRON & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH HONGGERBERG, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RP IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY. RI D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Fiandrini, Emanuele/C-4549-2008; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; alpat, ali behcet/G-6290-2013; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Josa, Isabel/K-5184-2014; OI D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Longo, Egidio/0000-0001-6238-6787; Ambrosi, Giovanni/0000-0001-6977-9559; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731; Berdugo, Javier/0000-0002-7911-8532; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; alpat, ali behcet/0000-0002-0116-1506; Cerrada, Marcos/0000-0003-0112-1691; Castellini, Guido/0000-0002-0177-0643; Doria, Alessandra/0000-0002-5381-2649; Faccini, Riccardo/0000-0003-2613-5141; Bertucci, Bruna/0000-0001-7584-293X; Filthaut, Frank/0000-0003-3338-2247; Goldstein, Joel/0000-0003-1591-6014 NR 17 TC 14 Z9 14 U1 0 U2 2 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. 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B PD JAN 16 PY 1997 VL 391 IS 3-4 BP 474 EP 480 DI 10.1016/S0370-2693(96)01583-3 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100037 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R DeBoeck, H Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Opitz, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK PAscale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, YB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F AF Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Aloisio, A Alverson, G Alviggi, MG Ambrosi, G Anderhub, H Andreev, VP Angelescu, T Anselmo, F Antreasyan, D Arefiev, A Azemoon, T Aziz, T Bagnaia, P Baksay, L Ball, RC Banerjee, S Banicz, K Barillere, R Barone, L Bartalini, P Baschirotto, A Basile, M Battiston, R Bay, A Becattini, F Becker, U Behner, F Berdugo, J Berges, P Bertucci, B Betev, BL Bhattacharya, S Biasini, M Biland, A Bilei, GM Blaising, JJ Blyth, SC Bobbink, GJ Bock, R Bohm, A Borgia, B Boucham, A Bourilkov, D Bourquin, M Boutigny, D Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Buytenhuijs, A Cai, XD Campanelli, M Capell, M Romeo, GC Caria, M Carlino, G Cartacci, AM Casaus, J Castellini, G Cavallari, F Cavallo, N Cecchi, C Cerrada, M Cesaroni, F Chamizo, M Chan, A Chang, YH Chaturvedi, UK Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chen, M Chiefari, G Chien, CY Choi, MT Cifarelli, L Cindolo, F Civinini, C Clare, I Clare, R Cohn, HO Coignet, G Colijn, AP Colino, N Commichau, V Costantini, S Cotorobai, F delaCruz, B Csilling, A Dai, TS DAlessandro, R deAsmundis, R DeBoeck, H Degre, A Deiters, K Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dorne, I Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y ElMamouni, H Engler, A Eppling, FJ Erne, FC Ernenwein, JP Extermann, P Fabre, M Faccini, R Falciano, S Favara, A Fay, J Fedin, O Felcini, M Fenyi, B Ferguson, T Fernandez, D Ferroni, F Fesefeldt, H Fiandrini, E Field, JH Filthaut, F Fisher, PH Forconi, G Fredj, L Freudenreich, K Furetta, C Galaktionov, Y Ganguli, SN GarciaAbia, P Gau, SS Gentile, S Gerald, J Gheordanescu, N Giagu, S Goldfarb, S Goldstein, J Gong, ZF Gratta, G Gruenewald, MW Gupta, VK Gurtu, A Gutay, LJ Hartmann, B Hasan, A Hatzifotiadou, D Hebbeker, T Herve, A vanHoek, WC Hofer, H Hoorani, H Hou, SR Hu, G Innocente, V Janssen, H Jenkes, K Jin, BN Jones, LW deJong, P JosaMutuberria, I Kasser, A Khan, RA Kamrad, D Kamyshkov, Y Kapustinsky, JS Karyotakis, Y Kaur, M KienzleFocacci, MN Kim, D Kim, JK Kim, SC Kim, YG Kinnison, WW Kirkby, A Kirkby, D Kirkby, J Kiss, D Kittel, W Klimentov, A Konig, AC Korolko, I Koutsenko, V Kraemer, RW Krenz, W Kuijten, H Kunin, A deGuevara, PL Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY Leggett, C LeGoff, JM Leiste, R Leonardi, E Levtchenko, P Li, C Lieb, E Lin, WT Linde, FL Lista, L Liu, ZA Lohmann, W Longo, E Lu, W Lu, YS Lubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mana, C Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D Mele, S Merola, L Meschini, M Metzger, WJ vonderMey, M Mi, Y Mihul, A vanMil, AJW Mirabelli, G Mnich, J Molnar, P Monteleoni, B Moore, R Morganti, S Moulik, T Mount, R Muller, S Muheim, F Nagy, E Nahn, S Napolitano, M NessiTedaldi, F Newman, H Niessen, T Nippe, A Nisati, A Nowak, H Opitz, H Organtini, G Ostonen, R Pandoulas, D Paoletti, S Paolucci, P Park, HK PAscale, G Passaleva, G Patricelli, S Paul, T Pauluzzi, M Paus, C Pauss, F Peach, D Pei, YJ Pensotti, S PerretGallix, D Petrak, S Pevsner, A Piccolo, D Pieri, M Pinto, JC Piroue, PA Pistolesi, E Plyaskin, V Pohl, M Pojidaev, V Postema, H Produit, N Prokofiev, D RahalCallot, G Rancoita, PG Rattaggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riemers, BC Riles, K Rind, O Ro, S Robohm, A Rodin, J Rodriguez, FJ Roe, BP Romero, L RosierLees, S Rosselet, P vanRossum, W Roth, S Rubio, JA Rykaczewski, H Salicio, J Sanchez, E Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Sauvage, G Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Schneegans, M Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Sens, JC Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A Soulimov, V Smith, B Spillantini, P Steuer, M Stickland, DP Stone, H Stoyanov, B Straessner, A Strauch, K Sudhakar, K Sultanov, G Sun, LZ Susinno, GF Suter, H Swain, JD Tang, XW Tauscher, L Taylor, L Ting, SCC Ting, SM Tonutti, M Tonwar, SC Toth, J Tully, C Tuchscherer, H Tung, KL Uchida, Y Ulbricht, J Uwer, U Valente, E VandeWalle, RT Vesztergombi, G Vetlitsky, I Viertel, G Vivargent, M Volkert, R Vogel, H Vogt, H Vorobiev, I Vorobyov, AA Vorvolakos, A Wadhwa, M Wallraff, W Wang, JC Wang, XL Wang, ZM Weber, A Wittgenstein, F Wu, SX Wynhoff, S Xu, J Xu, ZZ Yang, BZ Yang, CG Yao, XY Ye, YB Yeh, SC You, JM Zalite, A Zalite, Y Zemp, P Zeng, Y Zhang, Z Zhang, ZP Zhou, B Zhou, Y Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Search for exclusive B decays to J and eta or pi(0) with the L3 detector SO PHYSICS LETTERS B LA English DT Article ID FORM-FACTORS; FACTORIZATION; MESONS; LEP AB A search for exclusive decays of B-d(0) and B-s(0) mesons has been preformed in the channels B-d(0) --> J eta, B-s(0) --> J eta, B-d(0) --> J(pi)(0) and B-s(0) --> J(pi)(0). The data smaple consisted of more than three and a half million hadronic Z decays collected by the L3 experiment at LEP from 1991 through 1995. No candidate events have been observed for any of the modes thus determining upper limits at 90% confidence level: 3.2 x 10(-4) on Br(B-d(0) --> J(pi)(0)) and the first experimental limits: Br(B-d(0) --> J eta) < 1.2 x 10(-3), Br(B-s(0) --> J eta) < 3.8 x 10(-3), Br(B-s(0) --> J pi(0)) < 1.2 x 10(-3). C1 RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-52056 AACHEN, GERMANY. NIKHEF H, NATL INST HIGH ENERGY PHYS, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV MICHIGAN, ANN ARBOR, MI 48109 USA. LAB ANNECY LE VIEUX PHYS PARTICULES, IN2P3, CNRS, F-74941 ANNECY LE VIEUX, FRANCE. JOHNS HOPKINS UNIV, BALTIMORE, MD 21218 USA. UNIV BASEL, INST PHYS, CH-4056 BASEL, SWITZERLAND. INST HIGH ENERGY PHYS, BEIJING 100039, PEOPLES R CHINA. HUMBOLDT UNIV BERLIN, D-10099 BERLIN, GERMANY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. UNIV FLORENCE, I-50125 FLORENCE, ITALY. CERN, EUROPEAN LAB PARTICLE PHYS, CH-1211 GENEVA 23, SWITZERLAND. WORLD LAB, FBLJA PROJECT, CH-1211 GENEVA 23, SWITZERLAND. UNIV GENEVA, CH-1211 GENEVA 4, SWITZERLAND. CHINESE UNIV SCI & TECHNOL, HEFEI 230029, ANHUI, PEOPLES R CHINA. SEFT, RES INST HIGH ENERGY PHYS, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. UNIV LECCE, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, IN2P3, INST PHYS NUCL LYON, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. IST NAZL FIS NUCL, I-80125 NAPLES, ITALY. UNIV NAPLES, I-80125 NAPLES, ITALY. UNIV CYPRUS, DEPT NAT SCI, NICOSIA, CYPRUS. UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, LA JOLLA, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATRON & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF H, NL-3584 CB UTRECHT, NETHERLANDS. PURDUE UNIV, W LAFAYETTE, IN 47907 USA. PAUL SCHERRER INST, CH-5232 VILLIGEN, SWITZERLAND. DESY, INST HOCHENERGIEPHYS, D-15738 ZEUTHEN, GERMANY. ETH ZURICH, CH-8093 ZURICH, SWITZERLAND. UNIV HAMBURG, D-22761 HAMBURG, GERMANY. RP IST NAZL FIS NUCL, VIA CELORIA 16, I-20133 MILAN, ITALY. RI D'Alessandro, Raffaello/F-5897-2015; Sanchez, Eusebio/H-5228-2015; Duran, Ignacio/H-7254-2015; rodriguez calonge, francisco javier/H-9682-2015; Rancoita, Pier Giorgio/J-9896-2015; Hoorani, Hafeez/D-1791-2013; Fedin, Oleg/H-6753-2016; Roth, Stefan/J-2757-2016; Kamyshkov, Yuri/J-7999-2016; Fiandrini, Emanuele/C-4549-2008; Berdugo, Javier/A-2858-2015; Lista, Luca/C-5719-2008; Kirkby, Jasper/A-4973-2012; Servoli, Leonello/E-6766-2012; alpat, ali behcet/G-6290-2013; bertucci, bruna/J-5237-2012; Cavallo, Nicola/F-8913-2012; Cerrada, Marcos/J-6934-2014; de la Cruz, Begona/K-7552-2014; Josa, Isabel/K-5184-2014; Vogel, Helmut/N-8882-2014; Ferguson, Thomas/O-3444-2014 OI D'Alessandro, Raffaello/0000-0001-7997-0306; Sanchez, Eusebio/0000-0002-9646-8198; Rancoita, Pier Giorgio/0000-0002-1990-4283; Roth, Stefan/0000-0003-3616-2223; Kamyshkov, Yuri/0000-0002-3789-7152; Berdugo, Javier/0000-0002-7911-8532; Kirkby, Jasper/0000-0003-2341-9069; Servoli, Leonello/0000-0003-1725-9185; alpat, ali behcet/0000-0002-0116-1506; Cerrada, Marcos/0000-0003-0112-1691; Vogel, Helmut/0000-0002-6109-3023; Ferguson, Thomas/0000-0001-5822-3731 NR 32 TC 6 Z9 6 U1 0 U2 2 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 JAN 16 PY 1997 VL 391 IS 3-4 BP 481 EP 490 DI 10.1016/S0370-2693(96)01584-5 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100038 ER PT J AU Allison, WWM Alner, GJ Ayres, DS Barrett, WL Bode, C Border, PM Brooks, CB Cobb, JH Cockerill, DJA Cotton, RJ Courant, H DeMuth, DM Fields, TH Gallagher, HR GarciaGarcia, C Goodman, MC Gray, RN Johns, K Kafka, T Kasahara, SMS Leeson, W Litchfield, PJ Longley, NP Lowe, MJ Mann, WA Marshak, ML May, EN Milburn, RH Miller, WH Mualem, L Napier, A Oliver, W Pearce, GF Perkins, DH Peterson, EA Petyt, DA Price, LE Roback, DM Ruddick, K Schmid, DJ Schneps, J Schub, MH Seidlein, RV Shupe, MA Stassinakis, A Sundaralingam, N Thomas, J Thron, JL Vassiliev, V Villaume, G Wakely, SP Wall, D Werkema, SJ West, N Wielgosz, UM AF Allison, WWM Alner, GJ Ayres, DS Barrett, WL Bode, C Border, PM Brooks, CB Cobb, JH Cockerill, DJA Cotton, RJ Courant, H DeMuth, DM Fields, TH Gallagher, HR GarciaGarcia, C Goodman, MC Gray, RN Johns, K Kafka, T Kasahara, SMS Leeson, W Litchfield, PJ Longley, NP Lowe, MJ Mann, WA Marshak, ML May, EN Milburn, RH Miller, WH Mualem, L Napier, A Oliver, W Pearce, GF Perkins, DH Peterson, EA Petyt, DA Price, LE Roback, DM Ruddick, K Schmid, DJ Schneps, J Schub, MH Seidlein, RV Shupe, MA Stassinakis, A Sundaralingam, N Thomas, J Thron, JL Vassiliev, V Villaume, G Wakely, SP Wall, D Werkema, SJ West, N Wielgosz, UM TI Measurement of the atmospheric neutrino flavour composition in Soudan 2 SO PHYSICS LETTERS B LA English DT Article ID FLUX AB The atmospheric neutrino flavour ratio measured using a 1.52 kton-year exposure of Soudan 2 is found to be 0.72 +/- 0.19(-0.07)(+0.05) relative to the expected value from a Monte Carlo calculation. The possible background of interactions of neutrons and photons produced in muon interactions in the rock surrounding the detector has been investigated and is shown not to produce low values of the ratio. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. UNIV MINNESOTA,MINNEAPOLIS,MN 55455. TUFTS UNIV,MEDFORD,MA 02155. WESTERN WASHINGTON UNIV,BELLINGHAM,WA 98225. RP Allison, WWM (reprint author), UNIV OXFORD,DEPT PHYS,OXFORD OX1 3RH,ENGLAND. RI Cotton, Richard/K-2175-2012 NR 19 TC 377 Z9 378 U1 0 U2 4 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 JAN 16 PY 1997 VL 391 IS 3-4 BP 491 EP 500 DI 10.1016/S0370-2693(96)01609-7 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WE121 UT WOS:A1997WE12100039 ER PT J AU Gibson, JK AF Gibson, JK TI Resonant laser ablation of lanthanides: Eu and Lu resonances in the 450-470 nm region SO ANALYTICAL CHEMISTRY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; ENHANCED IONIZATION; SPECTRUM; PHOTOIONIZATION; TRANSITIONS; FLAMES; OXIDE; GAAS AB Resonant laser ablation (RLA) of solids with a pulsed dye laser achieves wavelength-specific enhancements in yields of particular metal ions (M(+)) by resonant photoionization or photoexcitation of atoms in the ablation plume. In the present study, RLA was performed for lambda = 450-470 nn on solids comprising selected lanthanide elements. Enhancements in yields of Eu+ and Lu+ occurred at wavelengths corresponding to one-photon resonant absorptions for the neutral atoms: In + hv --> Ln*. The excited Ln* were subsequently preferentially ionized by the quasi-thermal collisional processes normally operative in the ablation plume: Ln* + kT --> Ln(+) + e(-). The excessive atomic absorption line widths of up to 40 cm(-1) (fwhm) were attributed primarily to collisional and Stark broadening in the dense plume. The strongest Eu+ resonances correspond to transitions from ground Eu (4f(7)6s(2) S-8(7/2)0) to 4f(7)6s6p P-8(J) levels at 21 445 (J = 5/2), 21 605 (J = 7/2), and 21 761 cm(-1) (J = 9/2). Primary Lu+ resonances were for excitation from ground In (5d6s(2) D-2(3/2)0) to 5d6s6p D-2(J) levels at 21 462 (J = 5/2) and 22 125 cm(-1) (J = 3/2). Other Ln(+) resonances were assigned to atomic transitions originating from levels as high as 7476 cm(-1) for Lu and 17 945 cm(-1) for Eu, which suggests a significant population of ablated atoms with internal energies up to similar to 2.2 eV. Resonance enhancements of similar to 10x were observed for Ln(+) compared with concurrently ablated nonresonant ions; optimization of such parameters as wavelength, irradiance, and ion extraction should result in substantially greater selectivity. The selective enhancement of Ln(+) increases the analytical utility of laser ablation mass spectrometry; the derived spectroscopic information complements conventional atomic absorption/emission techniques and can illuminate the role of excited state atoms in the ablation process. RP Gibson, JK (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 35 TC 9 Z9 10 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JAN 15 PY 1997 VL 69 IS 2 BP 111 EP 117 DI 10.1021/ac960805i PG 7 WC Chemistry, Analytical SC Chemistry GA WC045 UT WOS:A1997WC04500001 ER PT J AU Ohnishi, A Randrup, J AF Ohnishi, A Randrup, J TI Inclusion of quantum fluctuations in wave packet dynamics SO ANNALS OF PHYSICS LA English DT Article ID HEAVY-ION COLLISIONS; ANTISYMMETRIZED MOLECULAR-DYNAMICS; NUCLEAR COLLISIONS; HOT NUCLEI; TRANSPORT-THEORY; FRAGMENT FLOW; MULTIFRAGMENTATION; EQUATION; DECAY; SYSTEM AB We discuss a method by which quantum fluctuations can be included in microscopic transport models based on wave packets that are not energy eigenstates. By including the next-to-leading order term in the cumulant expansion of the statistical weight, which corresponds to the wave packets having Poisson energy distributions, we obtain a much improved global description of the quantum statistical properties of the many-body system. In the case of atomic nuclei, exemplified by C-12 and Ca-40, the standard liquid-drop results are reproduced at low temperatures and a phase transformation to a fragment gas occurs as the temperature is raised. The treatment can be extended to dynamical scenarios by means of a Langevin force emulating the transitions between the wave packets. The general form of the associated transport coefficients is derived and it is shown that the appropriate microcanonical equilibrium distribution is achieved in the course of the time evolution. Finally, invoking Fermi's golden rule, we derive specific expressions for the transport coefficients and verify that they satisfy the fluctuation-dissipation theorem. (C) 1997 Academic Press, Inc. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. RP Ohnishi, A (reprint author), HOKKAIDO UNIV, FAC SCI, DEPT PHYS, SAPPORO, HOKKAIDO 060, JAPAN. RI Ohnishi, Akira/F-7403-2011 OI Ohnishi, Akira/0000-0003-1513-0468 NR 43 TC 21 Z9 21 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0003-4916 J9 ANN PHYS-NEW YORK JI Ann. Phys. PD JAN 15 PY 1997 VL 253 IS 2 BP 279 EP 309 DI 10.1006/aphy.1996.5626 PG 31 WC Physics, Multidisciplinary SC Physics GA WG812 UT WOS:A1997WG81200003 ER PT J AU Clark, ME Rose, KA AF Clark, ME Rose, KA TI Individual-based model of stream-resident rainbow trout and brook char: Model description, corroboration, and effects of sympatry and spawning season duration SO ECOLOGICAL MODELLING LA English DT Article DE individual-based model; Salvelinus fontinalis; Oncorhynchus mykiss; competition; sympatry; allopatry ID SALMO-TRUTTA L; SALVELINUS-FONTINALIS; POPULATION-DYNAMICS; APPALACHIAN STREAM; SMALLMOUTH BASS; BROWN TROUT; GAIRDNERI; TEMPERATURE; GROWTH; FOOD AB An individual-based model of the population dynamics of sympatric rainbow trout (Oncorhynchus mykiss) and brook char (Salvelinus fontinalis) is described and analyzed. The model simulates daily growth, mortality, movement, and spawning over the full life cycle of each species for 100 years in a compartmentalized, hypothetical stream configured for the southern Appalachian mountains, USA. Egg and alevin development is temperature-dependent with mortality having constant, spatial, and temperature-dependent components. Daily growth of fry, juveniles, and adults is based on bioenergetics and consumption of drift prey. Mortality rate of fry through adults decreases with length. Model predictions of densities, growth, age, and size structure were similar to those observed in southern Appalachian streams. Five different conditions were simulated to explore the population dynamics and competition between the two species: (1) sympatric populations (baseline), (2) allopatric brook char, (3) allopatric rainbow trout, (4) and (5) sympatric populations with reduced or increased spawning season durations. Results indicated that density-dependence mainly operated during the fry and juvenile stages. Brook char were more affected by interspecific competition than rainbow trout, and crowding of fry negatively affected brook char (with little effect on rainbow trout), whereas low fry density favored brook char. (C) 1997 Elsevier Science B.V. C1 OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT ECOL & EVOLUTIONARY BIOL,KNOXVILLE,TN 37996. NR 64 TC 35 Z9 38 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD JAN 15 PY 1997 VL 94 IS 2-3 BP 157 EP 175 DI 10.1016/S0304-3800(96)00010-5 PG 19 WC Ecology SC Environmental Sciences & Ecology GA WW592 UT WOS:A1997WW59200005 ER PT J AU Kreutzer, U Jue, T AF Kreutzer, U Jue, T TI Metabolic response in Arenicola marina to limiting oxygen as reflected in the H-1-NMR oxymyoglobin signal SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Article DE NMR; oxygen; invertebrate; myoglobin; hypoxia ID MAGNETIC-RESONANCE; CALORIMETRY; MYOCARDIUM; MYOGLOBIN; INVIVO AB Many intertidal animals can endure prolonged periods of environmental stress and have developed strategies to preserve a functioning energy state in the cell. Recent H-1/P-31-NMR techniques have allowed investigators to monitor directly mammalian tissue metabolism in vivo. In particular, the signals of myoglobin (Mb) offer a unique opportunity to explore the intracellular oxygen-partial-pressure [p(O-2)] interaction in Arenicola marina, a standard model to study hypoxia tolerance in invertebrates. The present study reveals that the H-1-NMR MbO(2) signal at -2.9 ppm is detectable in tissue and reflects directly the oxygenated state. As the p(O-2) declines, MbO(2) saturation and oxygen consumption decrease. However, phosphotaurocyamine concentration remains unaltered until the MbO(2) saturation falls below 33%. The extracellular to intracellular p(O-2) gradient appears substantial. The study establishes the H-1-NMR technique as an approach to measure the intracellular p(O-2) with an oxygenated state marker and presents the interrelationship between oxygen and the metabolic adaptation during hypoxic stress. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616. FU NIGMS NIH HHS [GM 44916] NR 32 TC 5 Z9 5 U1 1 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD JAN 15 PY 1997 VL 243 IS 1-2 BP 233 EP 239 DI 10.1111/j.1432-1033.1997.0233a.x PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WE132 UT WOS:A1997WE13200030 PM 9030744 ER PT J AU DeAzevedo, WF Leclerc, S Meijer, L Havlicek, L Strnad, M Kim, SH AF DeAzevedo, WF Leclerc, S Meijer, L Havlicek, L Strnad, M Kim, SH TI Inhibition of cyclin-dependent kinases by purine analogues - Crystal structure of human cdk2 complexed with roscovitine SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Article DE cell cycle; cyclin-dependent kinase; purine; protein-kinase inhibitor; anti-tumor agent ID BUTYROLACTONE-I; PROTEIN-KINASE; CDC2 KINASE; SELECTIVE INHIBITOR; P34(CDC2) KINASE; CARCINOMA-CELLS; P34CDC2; PHOSPHORYLATION; OLOMOUCINE; 6-DIMETHYLAMINOPURINE AB Cyclin-dependent kinases (cdk) control the cell division cycle (cdc). These kinases and their regulators are frequently deregulated in human tumours. A potent inhibitor of cdks, roscovitine [2-(1-ethyl-2-hydroxyethylamino)-6-benzylamino-9-isopropylpurine], was identified by screening a series of C2,N-6,N9-substituted adenines on purified cdc2/cyclin B. Roscovitine displays high efficiency and high selectivity (Meijer, L., Borgne, A., Mulner, O., Chong, J. P. J., Blow, J. J., Inagaki, N., Inagaki, M., Delcros, J.-G. & Moulinoux, J.-P. (1997) Eur. J. Biochem. 243, 527-536). It behaves as a competitive inhibitor for ATP binding to cdc2. We determined the crystal structure of a complex between cdk2 and roscovitine at 0.24-nm (2.4 Angstrom) resolution and refined to an R(factor) of 0.18. The purine portion of the inhibitor binds to the adenine binding pocket of cdk2. The position of the benzyl ring group of the inhibitor enables the inhibitor to make contacts with the enzyme not observed in the ATP-complex structure. Analysis of the position of this benzyl ring explains the specificity of roscovitine in inhibiting cdk2. The structure also reveals that the (R)-stereoisomer of roscovitine is bound to cdk2. The (R)-isomer is about twice as potent in inhibiting cdc2/cyclin B than the (S)-isomer. Results from structure/activity studies and from analysis of the cdk2/roscovitine complex crystal structure should allow the design of even more potent cdk inhibitors. C1 CNRS,BIOL STN,F-29682 ROSCOFF,FRANCE. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA. CHARLES UNIV,INST TOXICOL & FORENS CHEM,FAC MED 1,PRAGUE,CZECH REPUBLIC. DEPT PLANT BIOTECHNOL,INST EXPT BOT,OLOMOUC,CZECH REPUBLIC. RI Havlicek, Libor/H-2171-2014; Strnad, Miroslav/H-1858-2014 NR 53 TC 470 Z9 477 U1 2 U2 14 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD JAN 15 PY 1997 VL 243 IS 1-2 BP 518 EP 526 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WE132 UT WOS:A1997WE13200066 PM 9030780 ER PT J AU Perou, CM Perchellet, A Jago, T Pryor, R Kaplan, J Justice, MJ AF Perou, CM Perchellet, A Jago, T Pryor, R Kaplan, J Justice, MJ TI Comparative mapping in the beige-satin region of mouse chromosome 13 SO GENOMICS LA English DT Article ID CHEDIAK-HIGASHI-SYNDROME; MURINE LEUKEMIA-VIRUS; GENETIC-LINKAGE MAP; LOCALIZATION; DNA; HYBRIDIZATION; MUTATIONS; HOMOLOGY; CLONING; DEFECT AB The proximal end of mouse chromosome (Chr) 13 contains regions conserved on human chromosomes 1q42-q44, 6p23-p21, and 7p22-p13. This region also contains mutations that may be models for human disease, including beige (human Chediak-Higashi syndrome). An interspecific backcross of SB/Le and Mus spretus mice was used to generate a molecular genetic linkage map of mouse chromosome 13 with an emphasis on the proximal region including beige (bg) and satin (so). This map provides the gene order of the two phenotypic markers bg and so relative to restriction fragment length polymorphisms and simple sequence length polymorphisms in 131 backcross animals. In parallel, we have created a physical map of the region using Nidogen (Nid) as a molecular starting point for cloning a YAC contig that was used to identify the beige gene. The physical map provides the fine-structure order of genes and anonymous DNA fragments that was not resolved by the genetic linkage mapping. The results show that the bg region of mouse Chr 13 is highly conserved on human Chr 1q42-q44 and provide a starting point for a complete functional analysis of the entire bg-sa interval. (C) 1997 Academic Press C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV UTAH,SCH MED,DEPT PATHOL,DIV CELL BIOL & IMMUNOL,SALT LAKE CITY,UT 84132. OI Perou, Charles/0000-0001-9827-2247 FU NCI NIH HHS [7R29CA63229-02]; NHLBI NIH HHS [HL26922]; NIGMS NIH HHS [T32GM07464] NR 44 TC 13 Z9 13 U1 0 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD JAN 15 PY 1997 VL 39 IS 2 BP 136 EP 146 DI 10.1006/geno.1996.4478 PG 11 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WE849 UT WOS:A1997WE84900002 PM 9027500 ER PT J AU Jensen, WP Hamza, AI Suh, IH Jacobson, RA Sommerer, SO AF Jensen, WP Hamza, AI Suh, IH Jacobson, RA Sommerer, SO TI The crystal and molecular structure of [2,2'-N,N'-O-bipyridylketonehydrate, N,N-bipyridylketone oxime, nitro cobalt(III) dihydrate] SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; cobalt complexes; bidentate ligand complexes; chelate complexes ID RAY STRUCTURE-ANALYSIS; DI-2-PYRIDYL KETONE; CHLORIDE AB The crystal structure of (2,2'-N,N'-O-dipyridylketonehydrate) (2'-N,N'-dipyridylketone oxime) nitro cobalt(III) dihydrate was determined by X-ray methods. Crystal data are: monoclinic space group C2/c, Z = 8, a = 13.026(5), b = 12.150(5), c = 28.60(1) Angstrom, beta = 103.37(3)degrees. The ketone hydrate is coordinated through the two pyridyl nitrogen atoms, N4 and N5, and an oxygen atom of the ketone hydrate, O2, as a tridentate ligand. The oxime molecule is coordinated through one of the pyridyl nitrogen atoms, N1, and the oxime nitrogen atom, N3, as a bidentate ligand. A nitrite ion occupies the sixth coordination site of the distorted octahedron. The cobalt coordination distances range from 1.896(9) to 1.994(9) Angstrom. The oxime ligand is nearly perpendicular to the equatorial plane of the octahedron and the coordinated oxygen atom of the dipyridyl ketone ligand is 9.27 degrees from the normal to the equatorial plane of the coordination octahedron. C1 CHUNGNAM NATL UNIV,DEPT PHYS,TAEJON 305764,SOUTH KOREA. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. BARRY UNIV,DEPT PHYS SCI,MIAMI SHORES,FL 33161. RP Jensen, WP (reprint author), S DAKOTA STATE UNIV,DEPT CHEM,BROOKINGS,SD 57007, USA. NR 11 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0020-1693 J9 INORG CHIM ACTA JI Inorg. Chim. Acta PD JAN 15 PY 1997 VL 254 IS 2 BP 367 EP 370 DI 10.1016/S0020-1693(96)05160-2 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WJ200 UT WOS:A1997WJ20000023 ER PT J AU Hebner, GA AF Hebner, GA TI Relative atomic chlorine density in inductively coupled chlorine plasmas SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID ETCHING REACTOR; REFERENCE CELL; DISCHARGE; CL; MODEL; ION AB Atomic chlorine is an important chemical species in plasma processing of silicon and III-V compound semiconductors. Two-photon laser-induced fluorescence (LIF) has been used to measure the relative atomic chlorine density in an inductively driven, rf discharge in chlorine gas. The Cl density in the center of the discharge was independent of rf power in the range of 150-400 W and increased a factor of 2 when the pressure was increased from 15 to 50 mTorr. LIF measurements performed on both levels of the chlorine spin-split ground state indicate similar trends for both energy levels in the inductive plasma mode. (C) 1997 American Institute of Physics. RP Hebner, GA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 24 TC 24 Z9 24 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1997 VL 81 IS 2 BP 578 EP 581 DI 10.1063/1.364192 PG 4 WC Physics, Applied SC Physics GA WD716 UT WOS:A1997WD71600005 ER PT J AU Lutterotti, L Matthies, S Wenk, HR Schultz, AS Richardson, JW AF Lutterotti, L Matthies, S Wenk, HR Schultz, AS Richardson, JW TI Combined texture and structure analysis of deformed limestone from time-of-flight neutron diffraction spectra SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID REFINEMENT; ORIENTATION AB The orientation distribution of a textured polycrystalline material has been traditionally determined from a few individual pole figures of lattice planes hkl, measured by x-ray or neutron diffraction, A new method is demonstrated that uses the whole diffraction spectrum, rather than extracted peak intensities, by combining the orientation distribution calculation with the crystallographic Rietveld method. The feasibility of the method is illustrated with time-of-flight neutron diffraction data of experimentally deformed polycrystalline calcite, It is possible to obtain quantitative information on texture, crystal structure, microstructure, and residual stress from highly incomplete pole figures and from regions of the diffraction spectrum containing many overlapping peaks. The approach provides a key for quantitative texture analysis of low symmetry compounds and of composites with complicated diffraction spectra. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. UNIV TRENT,DIPARTIMENTO INGN MAT,I-38050 TRENT,ITALY. SEOUL NATL UNIV,SCH MAT SCI & ENGN,SEOUL 151742,SOUTH KOREA. RP Lutterotti, L (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. RI Lutterotti, Luca/E-2426-2014 OI Lutterotti, Luca/0000-0002-0949-8322 NR 33 TC 317 Z9 319 U1 3 U2 46 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1997 VL 81 IS 2 BP 594 EP 600 DI 10.1063/1.364220 PG 7 WC Physics, Applied SC Physics GA WD716 UT WOS:A1997WD71600008 ER PT J AU Dick, JJ AF Dick, JJ TI Anomalous shock initiation of detonation in pentaerythritol tetranitrate crystal SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INDUCED LUMINESCENCE; COPPER-POWDER; ORIENTATION; DEFORMATION; COMPACTION; SOLIDS AB The anomalous, low-stress, shock initiation of detonation observed in earlier studies of pentaerythritol tetranitrate single crystals was examined in more detail experimentally. Time-resolved particle-velocity histories were obtained for [110], [001] and [100] orientations of single-crystal pentaerythritol tetranitrate explosive for shock input stresses of 4-7 GPa using laser interferometry instrumentation. At about 4.2 GPa an elastic-plastic, two-wave structure was noted in [110] and [001] orientations, and a single shock wave for [100] orientation. The two-wave structure provides an explanation for the anomalous shock initiation sensitivity and intermediate velocity transition previously observed in [110] orientation at this stress level. It also explains details of fluorescent emission histories from [110] and [001] crystals previously measured. The orientation-dependent results are consistent with the model of steric hindrance to shear at the molecular level. Fits to the elastic Hugoniot data in [110] and [001] orientations are given as well as a revised fit for the bulk Hugoniot. (C) 1997 American Institute of Physics. RP LOS ALAMOS NATL LAB, MS P952, LOS ALAMOS, NM 87545 USA. NR 52 TC 83 Z9 87 U1 1 U2 10 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1997 VL 81 IS 2 BP 601 EP 612 DI 10.1063/1.364201 PG 12 WC Physics, Applied SC Physics GA WD716 UT WOS:A1997WD71600009 ER PT J AU McIntyre, PC Wu, DT Nastasi, M AF McIntyre, PC Wu, DT Nastasi, M TI Interdiffusion in epitaxial Co/Pt multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID PERPENDICULAR MAGNETIC-ANISOTROPY; PT/CO MULTILAYERS; METAL STRUCTURES; FILMS; SUPERLATTICES; GROWTH AB Interdiffusion kinetics were measured using x-ray diffraction methods in epitaxial (001) and (111) Co/Pt multilayers in which the chemical modulation wavelength was in the range 2.5-4.0 nm. Multilayers were prepared by e-beam evaporation and were subsequently annealed in vacuum at temperatures between 275 and 375 degrees C. The activation enthalpy of the interdiffusion process in this temperature range was estimated using a novel approach for scaling nonlinear diffusion data. Activation enthalpies for interdiffusion in (001) and (111) multilayers were determined to be 1.1+/-0.2 and 0.8+/-0.2 eV, respectively. The low values obtained for the activation enthalpies may result from coherency strains or ''short-circuit'' diffusion in the faulted, epitaxial multilayers. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. NR 39 TC 26 Z9 26 U1 0 U2 3 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1997 VL 81 IS 2 BP 637 EP 645 DI 10.1063/1.364221 PG 9 WC Physics, Applied SC Physics GA WD716 UT WOS:A1997WD71600013 ER PT J AU Keavney, DJ Fullerton, EE Bader, SD AF Keavney, DJ Fullerton, EE Bader, SD TI Perpendicular conductance and magnetic coupling in epitaxial Fe/MgO/Fe(100) trilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILM; MGO FILMS; GROWTH; TEMPERATURE; MAGNETORESISTANCE; JUNCTION; LAYERS; GAAS AB A series of Fe/MgO/Fe(100) trilayer structures with MgO thicknesses ranging from 12 to 1000 Angstrom was grown at 75 degrees C by molecular beam epitaxy. The structures are all epitaxial, and for MgO thicknesses below 75 Angstrom, the Fe layers are ferromagnetically coupled. The MgO spacer thickness dependence of the coupling energy shows a change in slope at 25 Angstrom; suggesting a change in growth morphology. Perpendicular transport measurements show ohmic current-voltage characteristics with high conductance up to 1000 Angstrom MgO interlayer thicknesses, indicating that the coupling is not due to spin-dependent tunneling. Investigations of the growth morphology reveal the existence of ferromagnetic bridges across the MgO layer. (C) 1997 American Institute of Physics. RP Keavney, DJ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 12 TC 21 Z9 21 U1 1 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1997 VL 81 IS 2 BP 795 EP 798 DI 10.1063/1.364163 PG 4 WC Physics, Applied SC Physics GA WD716 UT WOS:A1997WD71600037 ER PT J AU Kemner, KM Idzerda, YU Harris, VG Chakarian, V Elam, WT Kao, CC Johnson, E Feng, YC Laughlin, DE Chen, CT Lee, KB Lodder, JC AF Kemner, KM Idzerda, YU Harris, VG Chakarian, V Elam, WT Kao, CC Johnson, E Feng, YC Laughlin, DE Chen, CT Lee, KB Lodder, JC TI Direct observation of Cr magnetic order in CoCrTa and CoCrPt thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LONGITUDINAL RECORDING MEDIA; CIRCULAR-DICHROISM; COMPOSITIONAL INHOMOGENEITIES; FE/CR/FE TRILAYERS; PROCESSING ASPECTS; ULTRATHIN FILMS; MICROSTRUCTURE; SEGREGATION; ANISOTROPY AB Magnetic circular dichroism measurements of room temperature, sputter deposited Co86Cr12Ta2 and CoS6Cr12Pt2 films were performed to investigate the local magnetic ordering of the Co and Cr atoms. The results demonstrate that the Cr has a net magnetic moment and that a small fraction of the Cr is magnetically oriented opposite to the Co moment. (C) 1997 American Institute of Physics. C1 USN,RES LAB,WASHINGTON,DC 20375. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. CARNEGIE MELLON UNIV,DEPT MAT SCI & ENGN,PITTSBURGH,PA 15213. SRRC,HSINCHU 30077,TAIWAN. POHANG UNIV SCI & TECHNOL,DEPT PHYS,POHANG 790784,SOUTH KOREA. POHANG UNIV SCI & TECHNOL,POHANG ACCELERATED LAB,POHANG 790784,SOUTH KOREA. UNIV TWENTE,MESA RES INST,NL-7500 AE ENSCHEDE,NETHERLANDS. RI Harris, Vincent/A-8337-2009 NR 31 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1997 VL 81 IS 2 BP 1002 EP 1004 DI 10.1063/1.364193 PG 3 WC Physics, Applied SC Physics GA WD716 UT WOS:A1997WD71600069 ER PT J AU Huang, JC Cheung, YS Evans, M Liao, CX Ng, CY Hsu, CW Heimann, P LefebvreBrion, H CossartMagos, C AF Huang, JC Cheung, YS Evans, M Liao, CX Ng, CY Hsu, CW Heimann, P LefebvreBrion, H CossartMagos, C TI A high-resolution vacuum ultraviolet photoionization, photoelectron, and pulsed field ionization study of CS2 near the CS2+(X(2)Pi(3/2,1/2)) thresholds SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID 193 NM PHOTODISSOCIATION; ADVANCED LIGHT-SOURCE; 2-PHOTON IONIZATION; VARIATIONAL METHOD; CHEMICAL-DYNAMICS; PHOTO-IONIZATION; CARBON-DISULFIDE; SPECTROSCOPY; SPECTRUM; ENERGY AB High-resolution photoionization efficiency (PIE) and pulsed field ionization photoelectron (PFI-PE) spectra for CS2 have been measured using coherent vacuum ultraviolet (VUV) laser radiation in the energy range of 81 050-82 100 cm(-1). The PIE and threshold photoelectron (TPE) spectra for CS2 in the energy range of 80 850-82 750 cm(-1) have also been obtained using synchrotron radiation for comparison with results of the VUV laser study. The analysis of the PIE spectra reveals three Rydberg series converging to the excited CS2+((2) Pi(1/2)) spin-orbit state. These series, with quantum defects of 1.430, 1.616, and 0.053, are associated with the [(2) Pi(1/2)]np sigma(u), [(2) Pi(1/2)]np pi(u), and [(2) Pi(1/2)]nf(u) configurations, respectively. The Stark shift effect on the ionization threshold of CS2 has been examined as a function of de electric fields (F) in the range of 0.65-1071 V/cm. The observed F dependence of the Stark shift for the ionization onset of CS2 is consistent with the prediction by the classical adiabatic field ionization formula. The extrapolation of the ionization onset to zero F yields accurate values for IE[CS2+(<(X)over tilde (2) Pi(3/2)>)]. This study shows that in order to determine accurate Ifs and to probe, autoionizing structures for molecular species by PIE measurements, it is necessary to minimize the electric field used for ion extraction. The assignment of Renner-Teller structures resolved in the VUV PFI-PE spectrum is guided by the recent nonresonant two-photon (N2P) PFI-PE and theoretical studies. The analysis of the PFI-PE spectrum also yields accurate values for IE[CS2+(<(X)over tilde (2) Pi(3/2,1/2)>)]. Taking average of the IE values determined by VUV-PFI-PE, N2P-PFI-PE, and Stark field extrapolation methods, we obtain a value of 81 285.7 +/- 2.8 cm(-1) for IE[CS2+(<(X)over tilde(2) Pi(3/2)>)]. For IE[CS2+((2) Pi(1/2))], we recommend a value of 81 727.1 +/- 0.5 cm(-1) determined by the Rydberg series analysis. A theoretical simulation of the (2) Pi(3/2)(0(0)(0)) and (2) Pi(1/2)(0(0)(0)) VUV-PFI-PE band profiles reproduces the observed branching ratio of 1.9 +/- 0.3 for CS2+(<(X)over tilde (2) Pi(3/2)>)/CS2+((2) Pi(1/2)). The relative intensities of vibronic structures observed in the VUV PFI-PE and TPE spectra are in agreement. Evidence is found, indicating that the strongly (Stark field induced) autoionizing Rydberg state, 17p sigma(u), which is approximate to 10 cm(-1) below the IE of CS2, has a minor contribution to the observed profile for the <(X)over tilde (2) Pi(3/2)>(0(0)(0)) PFI-PE band. (C) 1997 American Institute of Physics. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. UNIV PARIS 11,PHOTOPHYS MOL LAB,F-91405 ORSAY,FRANCE. UNIV CALIF BERKELEY,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DIV ACCELERATOR & FUS RES,ADV LIGHT SOURCE,BERKELEY,CA 94720. NR 62 TC 36 Z9 37 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1997 VL 106 IS 3 BP 864 EP 877 DI 10.1063/1.473967 PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD070 UT WOS:A1997WD07000005 ER PT J AU Li, X Huang, YL Flesch, GD Ng, CY AF Li, X Huang, YL Flesch, GD Ng, CY TI A state-selected study of the ion-molecule reactions O+(D-2,P-2)+H2O SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TOTAL CROSS-SECTIONS; SPACE-SHUTTLE; CHARGE-EXCHANGE; RATE COEFFICIENT; H2O; PHOTOIONIZATION; AR+(2P3/2,1/2); COLLISIONS; VICINITY; DYNAMICS AB State-selected absolute cross sections for H2O+ and OH+ formed by the O+(D-2, P-2)+H2O reactions have been measured in the center-of-mass collision energy (E(c.m.)) range of approximate to 0.10-30 eV. The charge transfer cross sections for O+(D-2)+H2O are significantly higher than those for O+(S-4)+H2O. This observation is attributed to the increased number of accessible exothermic product channels for O+(D-2)+H2O. While the H2O+ cross sections for O+(P-2)+H2O are comparable to those from O+(S-4)+H2O at E(c.m.).greater than or equal to 1 eV, the H2O+ cross sections for O+(P-2)+H2O at E(c.m.) <1 eV are substantially lower than those for O+(S-4)+H2O. The lower H2O+ cross sections observed for O+(P-2)+H2O are rationalized as due to further dissociation of excited charge transfer H2O+ ions and/or the efficient competition of the OH++OH product channel. The cross sections for OH+ from O+(D-2,P-2)+H2O are significantly greater than those from O+(S-4)+H2O. The majority of OH+ ions from O+(D-2,P-2)+H2O are associated with exothermic channels corresponding to the formation OH+(X(3) Sigma(-),(1) Delta,A (3) Pi)+OH. The comparison of the sum (sigma(T)) of the cross sections for H2O+ and OH+ from O+(S-4)+H2O to those from O+(D-2)+H2O and O+(P-2)+H2O shows that sigma(T)'s for O+(S-4)+H2O and O+(P-2)+H2O are comparable, whereas the sigma(T) values for O+(D-2)+H2O are greater than those for O+(S-4)+H2O and O+(P-2)+H2O. The sigma(T) values are found to conform with the 1/E(c.m.) dependence at low E(c.m.)'s, indicating that the ion-dipole interaction plays an important role in the formation of the long-lived collision complexes. The high cross sections for H2O+ and OH+ from O+(D-2,P-2)+H2O observed here suggest that these reactions should be included in the simulation of the H2O+ and H3O+ ion density data obtained in 3 space-borne mass spectrometric experiments. (C) 1997 American Institute of Physics. C1 US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT CHEM, AMES, IA 50011 USA. NR 44 TC 7 Z9 7 U1 0 U2 1 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 JAN 15 PY 1997 VL 106 IS 3 BP 928 EP 933 DI 10.1063/1.473172 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD070 UT WOS:A1997WD07000011 ER PT J AU Li, ZM Apkarian, VA Harding, LB AF Li, ZM Apkarian, VA Harding, LB TI Theoretical study of solid hydrogens doped with atomic oxygen SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACES; CONFIGURATION-INTERACTION CALCULATIONS; CORRELATED MOLECULAR CALCULATIONS; PATH CENTROID DENSITY; GAUSSIAN-BASIS SETS; TO-PARA CONVERSION; HELIUM CLUSTERS; INFRARED-SPECTROSCOPY; LASER SPECTROSCOPY; EXCITED-STATES AB Structure and reaction dynamics in solid H-2/D-2 doped with O(P-3, D-1, S-1) is investigated through simulations based on accurate ab initio potential energy surfaces. The ab initio calculations are performed at MCSCF level, with neglect of spin-orbit interactions. The dynamical simulations rely on nonadditive effective potentials, taking into account the anisotropy of the open shell atom by using diabatic representations for the globally fitted potential energy surfaces of O-H-2. The ground state of the doped solid is well described as O(P-3) isolated in para-H-2(J=0) since the atom-molecule interaction anisotropy is not sufficient to orient H-2. O(P-3) atoms radially localize the nearest-neighbor shell, and lead to a linear increase in the density of the solid as a function of impurity concentration. The doped solid is stable at cryogenic temperatures, with a free energy barrier for recombination of next nearest-neighbor O(P-3) atoms of 120 K. The solid state O(D-1) + H-2 reaction is considered in some depth. While in high symmetry sites the reaction is forbidden, even at 4 K, thermal fluctuations are sufficient to promote the insertion reaction. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB, THEORET CHEM GRP, ARGONNE, IL 60439 USA. RP Li, ZM (reprint author), UNIV CALIF IRVINE, DEPT CHEM, IRVINE, CA 92697 USA. NR 70 TC 18 Z9 18 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1997 VL 106 IS 3 BP 942 EP 953 DI 10.1063/1.473174 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD070 UT WOS:A1997WD07000013 ER PT J AU Evans, M Ng, CY Hsu, CW Heimann, P AF Evans, M Ng, CY Hsu, CW Heimann, P TI A high resolution energy-selected kinetic energy release study of the process SF6+h nu->SF+ (5)+F+e(-): Heat of formation of SF+ (5) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ADVANCED LIGHT-SOURCE; CHEMICAL-DYNAMICS; 2 ISOMERS; DISSOCIATION; THERMOCHEMISTRY; SF5-CENTER-DOT; ENERGETICS; BEAMLINE; IONS; SF5+ AB Using the newly constructed photoelectron-photoion coincidence apparatus associated with the chemical dynamics beamline at the advanced light source, we have performed a high resolution energy-selected kinetic energy release measurement for the dissociative photoionization process SF6 + hv --> SF5+ + F + e(-). After taking into account the center-of-mass kinetic energy release, the thermochemical threshold for this process is determined to be 14.11 +/- 0.08 eV. This value yields 18.5 +/- 1.9 and -202.9 +/- 2.2 kcal/mol for the heats of formation at 0 K for SF5+ and SF5, respectively. (C) 1997 American Institute of Physics. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ACCELERATOR & FUS RES,ADV LIGHT SOURCE,BERKELEY,CA 94720. NR 29 TC 36 Z9 38 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1997 VL 106 IS 3 BP 978 EP 981 DI 10.1063/1.473963 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD070 UT WOS:A1997WD07000016 ER PT J AU Curtiss, LA Raghavachari, K Redfern, PC Pople, JA AF Curtiss, LA Raghavachari, K Redfern, PC Pople, JA TI Assessment of Gaussian-2 and density functional theories for the computation of enthalpies of formation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID SET MODEL CHEMISTRY; MOLECULAR-ENERGIES; PROTON AFFINITIES; 2ND-ROW COMPOUNDS; ELECTRON-GAS; THERMOCHEMISTRY; APPROXIMATION; GEOMETRIES; EXCHANGE; ACCURATE AB A set of 148 molecules having well-established enthalpies of formation at 248 K is presented. This set, referred to as the G2 neutral test set, includes the 55 molecules whose atomization energies were used to test Gaussian-2 (G2) theory [J. Chem. Phys. 94, 7221 (1991)] and 93 new molecules. The G2 test set includes 29 radicals, 35 nonhydrogen systems, 22 hydrocarbons, 47 substituted hydrocarbons, and 15 inorganic hydrides. It is hoped that this new test set will provide a means for assessing and improving new theoretical models. From an assessment of G2 and density functional theories (DFT) on this test set it is found that G2 theory is the most reliable method both in terms of average absolute deviation (1.58 kcal/mol) and maximum; deviation (8.2 kcal/mol). The largest deviations between experiment and G2 theory occur for molecules having multiple halogens. Inclusion of spin-orbit effects reduces the average absolute deviation to 1.47 kcal/mol and significantly improves the results for the chlorine substituted molecules, but little overall improvement is seen for the fluorine substituted molecules. Of the two modified versions of G2 theory examined in this study, G2(MP2,SVP) theory (average absolute deviation = 1.93 kcal/mol) performs better than G2(MP2) theory (2.04 kcal/mol). The G2(MP2,SVP) theory is found to perform very well for hydrocarbons, radicals, and inorganic hydrides. Of the seven DFT methods investigated, the B3LYP method has the smallest average absolute deviation (3.11 kcal/mol). It also has a significantly larger distribution of error than the G2 methods with a maximum deviation of 20.1 kcal/mol. (C) 1997 American Institute of Physics. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. RP Curtiss, LA (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 45 TC 1582 Z9 1614 U1 11 U2 92 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1997 VL 106 IS 3 BP 1063 EP 1079 DI 10.1063/1.473182 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD070 UT WOS:A1997WD07000024 ER PT J AU Melenkevitz, J Curro, JG AF Melenkevitz, J Curro, JG TI Optimized cluster theory of polymer blends: General formulation and application to isotopic polyethylene mixtures SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTERACTION SITE FLUIDS; INTEGRAL-EQUATION; INTRAMOLECULAR STRUCTURES; DEUTERATED POLYBUTADIENE; INTERACTION PARAMETER; CHEMICAL-EQUILIBRIA; MOLECULAR LIQUIDS; MONOMER STRUCTURE; CLASSICAL FLUIDS; LOCAL-STRUCTURE AB A theory for the thermodynamic properties of binary polymer blends was developed and applied to predict the compositional dependence of the effective chi parameter chi(S) in model isotopic polyethylene mixtures. The theory is a generalization of the optimized cluster theory for single component molecular fluids. Starting from exact cluster expansions for the Helmholtz free energy and pair-correlation functions in a molecular mixture developed by Chandler et al., a series of transformations was performed to yield approximate expressions for these quantities. The resulting theory was demonstrated to be equivalent to a set of diagrammatically proper integral equations. For model isotopic polyethylene blends, we calculated the various partial structure factors in the mixture and used them to predict the compositional dependence of chi(S). The calculated values of chi(S) were found to be in reasonable agreement with recent neutron-scattering measurements but the theory underestimates the compositional dependence relative to the experiment. Deviations from random mixing that extend well beyond monomeric length scales were predicted in this blend system. (C) 1997 American Institute of Physics. C1 LOUISIANA STATE UNIV,DEPT CHEM,BATON ROUGE,LA 70803. RP Melenkevitz, J (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 48 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 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1997 VL 106 IS 3 BP 1216 EP 1230 DI 10.1063/1.473218 PG 15 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD070 UT WOS:A1997WD07000038 ER PT J AU Gallagher, PG Petruzzi, MJ Weed, SA Zhang, ZS Marchesi, SL Mohandas, N Morrow, JS Forget, BG AF Gallagher, PG Petruzzi, MJ Weed, SA Zhang, ZS Marchesi, SL Mohandas, N Morrow, JS Forget, BG TI Mutation of a highly conserved residue of beta I spectrin associated with fatal and near-fatal neonatal hemolytic anemia SO JOURNAL OF CLINICAL INVESTIGATION LA English DT Article DE membrane skeleton; mutation; molecular modeling; skeletal muscle; spectrin ID HUMAN-ERYTHROCYTE SPECTRIN; EXON-INTRON ORGANIZATION; TETRAMER BINDING-SITE; RED-CELL SPECTRIN; HEREDITARY ELLIPTOCYTOSIS; SELF-ASSOCIATION; NUCLEOTIDE-SEQUENCE; FUNCTIONAL DOMAINS; SKELETAL-MUSCLE; MESSENGER-RNA AB We studied an infant with severe nonimmune hemolytic anemia and hydrops fetalis at birth. His neonatal course was marked by ongoing hemolysis of undetermined etiology requiring repeated erythrocyte transfusions. He has remained transfusion-dependent for more than 2 yr. A previous sibling born with hemolytic anemia and hydrops fetalis died on the second day of life. Peripheral blood smears from the parents revealed rare elliptocytes. Examination of their erythrocyte membranes revealed abnormal mechanical stability as well as structural and functional abnormalities in spectrin. Genetic studies revealed that the proband and his deceased sister were homozygous for a mutation of beta I Sigma 1 spectrin, L2025R, in a region of spectrin that is critical for normal function. The importance of leucine in this position of the proposed triple helical model of spectrin repeats is highlighted by its evolutionary conservation in all beta spectrins from Drosophila to humans. Molecular modeling demonstrated the disruption of hydrophobic interactions in the interior of the triple helix critical for spectrin function caused by the replacement of the hydrophobic, uncharged leucine by a hydrophilic, positively charged arginine. This mutation must also be expressed in the beta I Sigma 2 spectrin found in muscle, yet pathologic and immunohistochemical examination of skeletal muscle from the deceased sibling was unremarkable. C1 YALE UNIV,SCH MED,DEPT INTERNAL MED,HEMATOL SECT,NEW HAVEN,CT 06520. YALE UNIV,SCH MED,DEPT PEDIAT,NEW HAVEN,CT 06520. YALE UNIV,SCH MED,DEPT CELL BIOL,NEW HAVEN,CT 06520. YALE UNIV,SCH MED,DEPT PATHOL,NEW HAVEN,CT 06520. YALE UNIV,SCH MED,DEPT GENET,NEW HAVEN,CT 06520. CHILDRENS HOSP,DIV HEMATOL ONCOL,BUFFALO,NY 14222. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI,BERKELEY,CA 94720. NR 61 TC 24 Z9 24 U1 0 U2 1 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 SN 0021-9738 J9 J CLIN INVEST JI J. Clin. Invest. PD JAN 15 PY 1997 VL 99 IS 2 BP 267 EP 277 DI 10.1172/JCI119155 PG 11 WC Medicine, Research & Experimental SC Research & Experimental Medicine GA WE311 UT WOS:A1997WE31100016 PM 9005995 ER PT J AU Bargar, JR Towle, SN Brown, GE Parks, GA AF Bargar, JR Towle, SN Brown, GE Parks, GA TI XAFS and bond-valence determination of the structures and compositions of surface functional groups and Pb(II) and Co(II) sorption products on single-crystal alpha-Al2O3 SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE Pb(II); Co(II); Al2O3; surfaces; adsorption; bond valence; hydrogen bond; hydroxyl group; XAFS; grazing-incidence XAFS; oxide-water interface; surface functional group ID ABSORPTION FINE-STRUCTURE; SOLID-SOLUTION INTERFACE; ANISOTROPIC STRUCTURE-ANALYSIS; ENERGY-LOSS SPECTROSCOPY; OXIDE-WATER INTERFACE; NEUTRON-DIFFRACTION; ELECTRONIC-STRUCTURE; ADSORPTION; MODEL; COMPLEXATION AB The structures and compositions of Pb(II) adsorption complexes and surface binding sites on alpha-Al2O3 (0001) and (1 (1) over bar 02) surfaces were investigated in the presence of water using grazing-incidence X-ray absorption fine structure (GI-XAFS) spectroscopy. Pb(II) ions were found to adsorb in an inner-sphere mode on alpha-Al2O3 (1 (1) over bar 02) but as outer-sphere complexes on alpha-Al2O3 (0001). The distance between the outer-sphere complexes and the surface places useful constraints on double-layer properties of water. A bond-valence model is described that relates the reactivities of surface functional groups and adsorption complexes to their molecular structures and compositions, and places constraints on the stoichiometries of adsorption reactions, including proton release. The EXAFS and modeling results suggest that Pb(II) and Co(II) ions bond to [Al-Al(Al) --> O-1/2--> and [Al-OH2+1/2] surface functional groups. In contrast, [(Al)(Al) > OH] groups complex Co(II) but not Pb(II). The results indicate the importance of using structurally defined surface sites to describe reactions at oxide-water interfaces. (C) 1997 Academic Press C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. STANFORD UNIV,DEPT MAT SCI & ENGN,STANFORD,CA 94305. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. NR 80 TC 130 Z9 131 U1 1 U2 19 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9797 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD JAN 15 PY 1997 VL 185 IS 2 BP 473 EP 492 DI 10.1006/jcis.1996.4574 PG 20 WC Chemistry, Physical SC Chemistry GA WD502 UT WOS:A1997WD50200024 ER PT J AU Puckett, EG Almgren, AS Bell, JB Marcus, DL Rider, WJ AF Puckett, EG Almgren, AS Bell, JB Marcus, DL Rider, WJ TI A high-order projection method for tracking fluid interfaces in variable density incompressible flows SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID GAS-DYNAMICS; CONSERVATION-LAWS; MULTIPHASE FLOWS; SOLIDIFICATION; ALGORITHMS; MODEL; COMBUSTION; DROPLETS; GROWTH AB We present a numerical method for computing solutions of the incompressible Euler or Navier-Stokes equations when a principal feature of the flow is the presence of an interface between two fluids with different fluid properties. The method is based on a second-order projection method for variable density flows using an ''approximate projection'' formulation. The boundary between the fluids is tracked with a second-order, volume-of-fluid interface tracking algorithm. We present results for viscious Rayleigh-Taylor problems at early time with equal and unequal viscosities to demonstrate the convergence of the algorithm. We also present computational results for the Rayleigh-Taylor instability in air-helium and for bubbles and drops in an air-water system without surface tension to demonstrate the behavior of the algorithm on problems with large density and viscosity contrasts. (C) 1997 Academic Press. C1 UNIV CALIF DAVIS, INST THEORET DYNAM, DAVIS, CA 95616 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, CTR COMPUTAT SCI & ENGN, BERKELEY, CA 94720 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Puckett, EG (reprint author), UNIV CALIF DAVIS, DEPT MATH, DAVIS, CA 95616 USA. OI Puckett, Elbridge Gerry/0000-0002-6589-7395 NR 64 TC 253 Z9 264 U1 3 U2 20 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 JAN 15 PY 1997 VL 130 IS 2 BP 269 EP 282 DI 10.1006/jcph.1996.5590 PG 14 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WK740 UT WOS:A1997WK74000010 ER PT J AU Feig, AL Masschelein, A Bakac, A Lippard, SJ AF Feig, AL Masschelein, A Bakac, A Lippard, SJ TI Kinetic studies of reactions of dioxygen with carboxylate-bridged diiron(II) complexes leading to the formation of (mu-oxo)diiron(III) complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID METHANE MONOOXYGENASE HYDROXYLASE; METHYLOCOCCUS-CAPSULATUS BATH; NUCLEAR MAGNETIC-RESONANCE; NONHEME IRON PROTEINS; REVERSIBLE FORMATION; RIBONUCLEOTIDE REDUCTASE; COPPER(I) COMPLEXES; CRYSTAL-STRUCTURE; MODEL COMPOUNDS; BINDING-SITES AB Stopped-flow kinetic studies of the reactions of [Fe-2(BIPhMe)(2)(O2CH)(4)] (1a), where BIPhMe = 2,2'-bis(1-methylimidazolyl)phenylmethoxymethane, and [Fe-2(OH)(Me(3)TACN)(2)(OAc)(2)](+) (2a), where TACN = 1,4,7-trimethyl-1,4,7-triazacyclononane, with O-2 are presented. In CHCl3 both reactions are first-order in [O-2] and secondorder in diiron(II) complex concentration. Mechanisms consistent with the kinetic data are proposed. The main feature of these schemes is a bimolecular pathway involving a tetranuclear (mu(4)-peroxo)diiron(II)diiron(III) species in the transition state. Evidence for carboxylate shifts in the oxidation mechanisms is presented, offering one possible way in which this class of structural equilibria might control the chemistry at related non-heme diiron centers in metalloproteins. C1 MIT, DEPT CHEM, CAMBRIDGE, MA 02139 USA. IOWA STATE UNIV, AMES LAB, AMES, IA 50011 USA. RI Feig, Andrew/B-7414-2011; OI Feig, Andrew/0000-0002-5783-1097 NR 73 TC 47 Z9 47 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 15 PY 1997 VL 119 IS 2 BP 334 EP 342 DI 10.1021/ja962814e PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA WC772 UT WOS:A1997WC77200010 ER PT J AU Xu, T Barich, DH Torres, PD Nicholas, JB Haw, JF AF Xu, T Barich, DH Torres, PD Nicholas, JB Haw, JF TI Carbon-13 chemical shift tensors for acylium ions: A combined solid state NMR and ab initio molecular orbital study SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; INCLUDING ATOMIC ORBITALS; SHIELDING TENSORS; PERTURBATION-THEORY; ACIDIC ZEOLITES; MAGIC-ANGLE; LOCALIZED QUANTITIES; ELECTRON CORRELATION; C-13; SUSCEPTIBILITIES AB We report the principal components of the C-13 chemical shift tensors for seven acylium ions, determined by both slow speed magic angle spinning (MAS) nuclear magnetic resonance (NMR) and theoretical methods. Experimentally, the acylium ions were prepared either by direct reaction of the parent acyl halides with metal halide powders, including frozen antimony pentafluoride, or by the reaction of alkyl halides with carbon monoxide on aluminum chloride (AlCl3). The generalization of our recent observation of the acetylium ion on AlCl3 to other cations is direct proof of free acylium ion intermediates in Friedel-Crafts acylation reactions. C-13 CP MAS NMR spectra of the acylium ions were acquired at temperatures ranging from 83 to 298 K, and the principal components of the C-13 chemical shift tensors were extracted by fitting the side band intensities of the MAS spectra. With the exception of the chloroacetylium ion, the acylium ions studied have isotropic C-13(1) chemical shifts of 154 +/- 1 ppm, but clear variations in the principal components of the shift tensors were measured. The carbenium carbons of the acetylium and 2,2-dimethylpropionylium ions have axially symmetric C-13 chemical shift tensors, consistent with the molecular symmetry (C-3 upsilon), while the chemical shift tensors of the other cations were characterized by non-zero asymmetry parameters. The observation of appreciably smaller chemical shift anisotropies for C-1 in the benzoylium ions versus the values for the corresponding carbon in the alkanoyl cations is consistent with charge delocalization into the ring substituent. Additional information on the acylium cations is provided by theoretical calculations. We optimized the geometries of the acylium ions using second-order Moller-Plesset perturbation theory (MP2) and the 6-311G* basis set. We then calculated the NMR data at the MP2 level using the gauge-including atomic orbital (GIAO) method and the double-zeta (dz) and triple-zeta polarized (tzp) basis sets of Horn and Ahlrichs. While the isotropic shifts calculated at the GIAO-RHF/tzp/dz level were in error by as much as 26 ppm, the GIAO-MP2 values were in excellent agreement with the experimental measurements, as were those for most of the principal components. The calculations were also used to determine the orientations of the principal components. The results of analysis of the MP2 wave functions help answer long standing questions regarding the structure and bonding of acylium cations. C1 TEXAS A&M UNIV, DEPT CHEM, LAB MAGNET RESONANCE & MOL SCI, COLLEGE STN, TX 77843 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 72 TC 21 Z9 21 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 15 PY 1997 VL 119 IS 2 BP 396 EP 405 DI 10.1021/ja962944n PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA WC772 UT WOS:A1997WC77200017 ER PT J AU Enderlein, J Erdmann, R AF Enderlein, J Erdmann, R TI Fast fitting of multi-exponential decay curves SO OPTICS COMMUNICATIONS LA English DT Article ID FLUORESCENCE AB In the analysis of time-resolved measurements of fluorescence decays, one is usually confronted with the essentially non-linear fitting problems. There are several standard methods for non-linear minimisation, but they are all very sensitive to initial guess parameters and are time-consuming. Recently, Sasaki and Masuhara and independently Apanasovich and Novikov proposed an elegant method of quasi-linearising the problem of multi-exponential fitting. In the present paper it will be shown, that their method can be improved by better taking into account the statistical character of the measured data. C1 PICOQUANT GMBH,D-12489 BERLIN,GERMANY. RP Enderlein, J (reprint author), LOS ALAMOS NATL LAB,CST-1,MS M888,LOS ALAMOS,NM 87545, USA. NR 14 TC 83 Z9 83 U1 3 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JAN 15 PY 1997 VL 134 IS 1-6 BP 371 EP 378 DI 10.1016/S0030-4018(96)00384-7 PG 8 WC Optics SC Optics GA WB601 UT WOS:A1997WB60100059 ER PT J AU Walecki, WJ Fittinghoff, DN Smirl, AL Trebino, R AF Walecki, WJ Fittinghoff, DN Smirl, AL Trebino, R TI Characterization of the polarization state of weak ultrashort coherent signals by dual-channel spectral interferometry SO OPTICS LETTERS LA English DT Article ID FREQUENCY-DOMAIN INTERFEROMETER; PHASE; AMPLITUDE; PULSES AB We demonstrate that dual-channel spectral interferometry in conjunction with a well-characterized reference pulse can be used to time resolve the polarization state of extremely weak ultrashort coherent signals from linear- and nonlinear-optical experiments by measuring the intensity and the phase of two orthogonal polarization components. In this way the signal is completely characterized. (C) 1997 Optical Society of America C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Walecki, WJ (reprint author), UNIV IOWA,LAB PHOTON & QUANTUM ELECT,100 IATL,IOWA CITY,IA 52242, USA. NR 14 TC 74 Z9 74 U1 1 U2 4 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JAN 15 PY 1997 VL 22 IS 2 BP 81 EP 83 DI 10.1364/OL.22.000081 PG 3 WC Optics SC Optics GA WD128 UT WOS:A1997WD12800005 PM 18183109 ER PT J AU Kopf, D Keller, U Emanuel, MA Beach, RJ Skidmore, JA AF Kopf, D Keller, U Emanuel, MA Beach, RJ Skidmore, JA TI 1.1-W cw Cr:LiSAF laser pumped by a 1-cm diode array SO OPTICS LETTERS LA English DT Article ID CRYSTALS AB We demonstrate 1.1-W cw output power from a diode-laser array-pumped Cr:LiSAF laser based on a concept that allows for pumping low-gain solid-state lasers at reduced temperature rise. We discuss scaling to higher powers as a function of diode power and define a figure of merit for evaluating given diode lasers as pump sources for low-gain solid-state lasers. (C) 1997 Optical Society of America C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Kopf, D (reprint author), SWISS FED INST TECHNOL,ETH HONGGERBERG,INST QUANTUM ELECT,CH-8093 ZURICH,SWITZERLAND. RI Keller, Ursula/N-2437-2016 OI Keller, Ursula/0000-0002-1689-8041 NR 16 TC 31 Z9 31 U1 1 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD JAN 15 PY 1997 VL 22 IS 2 BP 99 EP 101 DI 10.1364/OL.22.000099 PG 3 WC Optics SC Optics GA WD128 UT WOS:A1997WD12800011 PM 18183115 ER PT J AU Vienna, JD Taylor, JA Balachandran, U AF Vienna, JD Taylor, JA Balachandran, U TI Processing and characterization of cobalt-stabilized YBa2Cu3Oy as a substrate for bulk superconductors SO PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS LA English DT Article DE YBa2Cu3Oy; YBa2Cu(3-x)CoxOy; substrate; coprocessing; characterization ID OXYGEN; FILMS; YBA2(CU1-XCOX)3OY; PRESSURE AB The physical properties of ceramic YBa2Cu(3-x)CoxOy were investigated to evaluate its usefulness as a substrate material for bulk YBa2Cu3Oy superconductors. YBa2Cu(3-x)CoxOy is thermally and chemically compatible with YBa2Cu3Oy and displays adequate electrical properties for a substrate material. An intensive investigation of materials with the nominal composition of YBa2Cu2.2Co0.8Oy revealed semiconductor-like behavior, with a room-temperature resistivity of 70 m Omega cm and a 77 K resistivity of 4 X 10(6) m Omega cm. Measured mechanical properties of YBa2Cu(3-x)CoxOy indicated that its flexural strength is low (60 MPa) and highly dependent on sintering conditions. YBa2Cu(3-x)CoxOy was found to be a good substrate material for bulk YBa2Cu3Oy superconductors. Coils with a continuous superconducting path, made from superconductor/substrate composites, were characterized,and Co diffusion into the superconducting layer was investigated. Optimal processing conditions are discussed. C1 ALFRED UNIV, NEW YORK STATE COLL CERAM, ALFRED, NY 14802 USA. ARGONNE NATL LAB, DIV ENERGY TECHNOL, ARGONNE, IL 60439 USA. 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 0921-4534 J9 PHYSICA C JI Physica C PD JAN 15 PY 1997 VL 274 IS 1-2 BP 125 EP 140 DI 10.1016/S0921-4534(96)00552-7 PG 16 WC Physics, Applied SC Physics GA WG882 UT WOS:A1997WG88200016 ER PT J AU Swartzentruber, BS AF Swartzentruber, BS TI Kinetics of Si monomer trapping at steps and islands on Si(001) SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; VARIABLE-TEMPERATURE STM; DIFFUSION-BARRIERS; SI(100) SURFACE; SINGLE-LAYER; BINDING; GROWTH; ADATOM AB Si monomers are observed in empty-state scanning tunneling microscopy images acquired between room temperature and 115 degrees C. The monomers are trapped at the ends of rebonded SE-type dimer rows. When monomers thermally escape from the traps, they rapidly diffuse along the substrate dimer row until they find another unoccupied trap or return to their original trap. The binding activation barrier at isolated traps is similar to 1.0 eV. A slightly lower barrier exists for monomers to hop between the ends of neighboring dimer rows-a process facilitating diffusion along segments of SE-type steps. RP Swartzentruber, BS (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 24 TC 33 Z9 33 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 3 BP 1322 EP 1325 DI 10.1103/PhysRevB.55.1322 PG 4 WC Physics, Condensed Matter SC Physics GA WF303 UT WOS:A1997WF30300011 ER PT J AU Parmigiani, F Sangaletti, L Goldoni, A delPennino, U Kim, C Shen, ZX Revcolevschi, A Dhalenne, G AF Parmigiani, F Sangaletti, L Goldoni, A delPennino, U Kim, C Shen, ZX Revcolevschi, A Dhalenne, G TI Electron-spectroscopy study of correlation mechanisms in CuGeO3 single crystals SO PHYSICAL REVIEW B LA English DT Article ID SPIN-PEIERLS TRANSITION; AUGER-SPECTRA; RESONANT PHOTOEMISSION; COMPOUND CUGEO3; SYSTEM CUGEO3; CUO; CU2O; SUPERCONDUCTORS; TEMPERATURE; CUPRATE AB X-ray (Al-K alpha) and resonant Cu 2p-->3d and Cu 3p-->3d photoemission valence-band spectra of high-quality CuGeO3 single crystals are reported and interpreted. In addition, an attempt is given to evaluate the charge transfer (Delta), the d-d Coulomb interaction (U-dd) energies, and the superexchange term (J) on the basis of L(2,3)M(4,5)M(4,5)-L(2,3)M(2,3)M(4,5) Auger transitions, and core-level spectra analyzed within the frame of the Anderson Hamiltonian in the impurity limit. The results clearly show that one-electron band-structure calculations do not account for the band gap approximate to 3.7 eV [M. Bassi, P. Camagni, R. Rolli, G. Samoggia, F. Parmigiani, and A. Revcolevschi (unpublished)] and the emission arising from many-body effects (correlated d(8) and d(8)-d(9) L hybridized states), while Delta and U-dd, found to be approximate to 4.2 and approximate to 6.7 eV, respectively, allow us to classify this compound as a charge-transfer insulator with a strong ionic character. In addition, energy-dependent electron-energy-loss measurements suggest that the forbidden d-d intraband transitions are centered at approximate to 1.6 eV, which justifies the blue color of CuGeO3, and the band gap is approximate to 3.7 eV, as required by the transparency of the crystal in the visible region of the electromagnetic spectrum. Finally, in the approximation allowed by the present models, J results to be of the order of -7 meV. C1 POLITECN MILAN, DIPARTIMENTO FIS, I-20133 MILAN, ITALY. UNIV BRESCIA, IST NAZL FIS MAT, I-25123 BRESCIA, ITALY. UNIV BRESCIA, DIPARTIMENTO CHIM & FIS MAT, I-25123 BRESCIA, ITALY. INFM, LAB TASC, I-34012 TRIESTE, ITALY. UNIV TRIESTE, DIPARTMENTO FIS, I-34127 TRIESTE, ITALY. IST NAZL FIS MAT, I-41100 MODENA, ITALY. UNIV MODENA, DIPARTIMENTO FIS, I-41100 MODENA, ITALY. STANFORD UNIV, DEPT APPL PHYS, STANFORD, CA 94305 USA. STANFORD UNIV, STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94305 USA. UNIV PARIS 11, UA 446 CNRS, LAB CHIM SOLIDES, F-91405 ORSAY, FRANCE. RP Parmigiani, F (reprint author), POLITECN MILAN, IST NAZL FIS MAT, PIAZZA LEONARDO DA VINCI 32, I-20133 MILAN, ITALY. RI Sangaletti, Luigi/M-9673-2014; Del Pennino, Umberto/L-1454-2016; OI Del Pennino, Umberto/0000-0001-9484-1449; Parmigiani, Fulvio/0000-0001-9529-7406; GOLDONI, Andrea/0000-0001-9989-3889; Sangaletti, Luigi/0000-0001-9312-5862 NR 46 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 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 3 BP 1459 EP 1468 DI 10.1103/PhysRevB.55.1459 PG 10 WC Physics, Condensed Matter SC Physics GA WF303 UT WOS:A1997WF30300039 ER PT J AU Lenosky, TJ Kress, JD Kwon, I Voter, AF Edwards, B Richards, DF Yang, S Adams, JB AF Lenosky, TJ Kress, JD Kwon, I Voter, AF Edwards, B Richards, DF Yang, S Adams, JB TI Highly optimized tight-binding model of silicon SO PHYSICAL REVIEW B LA English DT Review ID ELECTRONIC-STRUCTURE CALCULATIONS; DENSITY-FUNCTIONAL CALCULATIONS; MOLECULAR-DYNAMICS SIMULATIONS; POINT-DEFECTS; SYSTEM-SIZE; INTERATOMIC POTENTIALS; 1ST-PRINCIPLES CALCULATIONS; MINIMIZATION APPROACH; MICROSCOPIC THEORY; SCALING ALGORITHM AB We have fit an orthogonal tight-binding model of silicon with a minimal (s,p) basis and a repulsive pair potential. The pair potential and the tight-binding matrix elements are represented as cubic splines with a 5.24-Angstrom fixed radial cutoff in order to allow maximum flexibility. Using a numerical procedure, the spline parameters were fit to simultaneously optimize agreement with ab initio force and energy data on clusters, liquid, and amorphous systems as well as experimental elastic constants, phonon frequencies, and Gruneisen parameter values. Many such fits were performed to obtain a potential that we judged to be optimal, within the implicit limitations of our potential form. The resulting optimized potential describes many properties very accurately and should be a useful model given its relative simplicity and speed. Our fitting method is not difficult to apply and should be applicable to many other systems. C1 CORNELL UNIV, ATOM & SOLID STATE PHYS LAB, ITHACA, NY 14853 USA. UNIV ILLINOIS, DEPT MAT SCI & ENGN, URBANA, IL 61801 USA. RP Lenosky, TJ (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. OI Voter, Arthur/0000-0001-9788-7194 NR 111 TC 99 Z9 102 U1 0 U2 17 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 JAN 15 PY 1997 VL 55 IS 3 BP 1528 EP 1544 DI 10.1103/PhysRevB.55.1528 PG 17 WC Physics, Condensed Matter SC Physics GA WF303 UT WOS:A1997WF30300047 ER PT J AU Fu, HX Zunger, A AF Fu, HX Zunger, A TI Local-density-derived semiempirical nonlocal pseudopotentials for InP with applications to large quantum dots SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC SURFACE PROPERTIES; TEMPERATURE-DEPENDENCE; SEMICONDUCTOR CLUSTERS; OPTICAL-PROPERTIES; MAGNETIC-FIELDS; POROUS SILICON; III-V; 1ST-PRINCIPLES; SUPERLATTICES; SPECTROSCOPY AB In the same way that atomic calculations have been used previously to extract bare ionic pseudopotentials, self-consistent bulk calculations can be used to construct screened atomic pseudopotentials. We use such a method to construct screened nonlocal atomic pseudopotentials for InP. A series of bulk, local-density-approximation (LDA) calculations are performed on a few InP crystal structures, covering a range of unit-cell volumes, to produce bulk potentials {V-LDA(G)}. By solving a set of linear equations, we extract from these crystalline potentials the corresponding screened atomic ''spherical LDA'' (SLDA) potentials v(SLDA)(alpha)(\q\) for sites alpha=In or P. In combination with the nonlocal part of the usual LDA pseudopotentials, these SLDA potentials give band structures and wave functions that are virtually indistinguishable from the self-consistent LDA results for bulk InP. Ln the next step, we apply linear changes to the loca!SLDA potentials (while keeping the nonlocal potentials at their LDA values), to fit the band structures to experiment. Interestingly, this removal of LDA eigenvalue errors requires only small and subtle changes in the potential-mostly an upshift in the region near the cation core, with nearly no change at the bond center. Furthermore, the linear changes to the SLDA potentials result mostly in an upshift of the conduction bands with little effect on the valence bands. Because only small changes in the potential suffice to fit the bands to experimental results, the wave functions remain virtually unchanged relative to those in the original LDA calculation. Hence, we obtain semiempirical pseudopotentials which can produce nb initio LDA-quality wave functions with experimentally measured band structures, effective masses, and deformation potentials. The potentials obtained here were deposited on an FTP site and can be used by interested readers. Since the resulting pseudopotentials are ''soft'' (with small high-momentum components), they can be applied within a plane-wave basis in combination with a Gaussian correction to large systems for which LDA calculations are prohibitively expensive. As an illustration, we apply our InP screened atomic pseudopotentials to calculate quantum size effects on the band gaps of InP dots with sizes up to 700 atoms. Good agreement is found between the theoretical and the experimental band gaps. Fitting the calculated band gaps E(g) (in unit of eV) versus the effective dot sizes D (in unit of Angstrom) gives E(g)=1.45+37.295/D-1.16. This prediction differs significantly from the quadratic size dependence D--2.0 expected from simple effective-mass theory. RP Fu, HX (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 58 TC 99 Z9 100 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 3 BP 1642 EP 1653 DI 10.1103/PhysRevB.55.1642 PG 12 WC Physics, Condensed Matter SC Physics GA WF303 UT WOS:A1997WF30300060 ER PT J AU McLean, JG Krishnamachari, B Peale, DR Chason, E Sethna, JP Cooper, BH AF McLean, JG Krishnamachari, B Peale, DR Chason, E Sethna, JP Cooper, BH TI Decay of isolated surface features driven by the Gibbs-Thomson effect in an analytic model and a simulation SO PHYSICAL REVIEW B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; THIN-FILMS; ORDERING KINETICS; LOW-TEMPERATURE; 2 DIMENSIONS; ISING SYSTEM; DIFFUSION; GROWTH; ANISOTROPY; TRANSITION AB A theory based on the thermodynamic Gibbs-Thomson relation is presented that provides the framework for understanding the time evolution of isolated nanoscale features (i.e., islands and pits) on surfaces. Two limiting cases are predicted, in which either diffusion or interface transfer is the limiting process. These cases correspond to similar regimes considered in previous works addressing the Ostwald ripening of ensembles of features. A third possible limiting case is noted for the special geometry of ''stacked'' islands. In these limiting cases, isolated features are predicted to decay in size with a power-law scaling in time: A proportional to(t(0)-t)(n), where A is the area of the feature, t(0) is the time at which the feature disappears, and n = 2/3 or 1. The constant of proportionality is related to parameters describing both the kinetic and equilibrium properties of the surface. A continuous-time Monte Carlo simulation is used to test the application of this theory to generic surfaces with atomic scale features. A method is described to obtain macroscopic kinetic parameters describing interfaces in such simulations. Simulation and analytic theory are compared directly, using measurements of the simulation to determine the constants of the analytic theory. Agreement between the two is very good over a range of surface parameters, suggesting that the analytic theory properly captures the necessary physics. It is anticipated that the simulation will be useful in modeling complex surface geometries often seen in experiments on physical surfaces, for which application of the analytic model is not straightforward. C1 CORNELL UNIV, ATOM & SOLID STATE PHYS LAB, ITHACA, NY 14853 USA. SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. NR 43 TC 98 Z9 98 U1 0 U2 8 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 JAN 15 PY 1997 VL 55 IS 3 BP 1811 EP 1823 DI 10.1103/PhysRevB.55.1811 PG 13 WC Physics, Condensed Matter SC Physics GA WF303 UT WOS:A1997WF30300078 ER PT J AU Soderlind, P Wills, JM Johansson, B Eriksson, O AF Soderlind, P Wills, JM Johansson, B Eriksson, O TI Structural properties of plutonium from first-principles theory SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; ELECTRONIC-STRUCTURE; CRYSTAL-STRUCTURE; ACTINIDE METALS; BULK PROPERTIES; PHASE-DIAGRAM; BAND; PRESSURE; SUPERCONDUCTIVITY; AMERICIUM AB First-principles theory is shown to account for the unique low-temperature crystal structure of plutonium metal (alpha-PU). Also the observed, and debated, upturn of the equilibrium volume between neptunium and plutonium is reproduced and found to be a consequence of the different crystal structures for these two metals. Thus it is shown that density-functional theory is able to accurately describe bonding properties of 5f electrons in an outstandingly complex system, where also relativistic effects are large. The electronic structure for alpha-Pu and for plutonium in competing close-packed crystal structures are also presented. Moreover, an explanation for the occurrence of the highly complex alpha-Pu structure is given. The mechanism is described in terms of a Peierls distortion in conjunction with a narrow 5f-band width. The energy gained from the splitting of the 5f bands outweighs the electrostatic energy which favors the high symmetry structures found for most other metals. At lower volumes we predict that plutonium should become bcc. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. UNIV UPPSALA,DEPT PHYS,CONDENSED MATTER THEORY GRP,S-75121 UPPSALA,SWEDEN. RP Soderlind, P (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT PHYS,LIVERMORE,CA 94550, USA. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 41 TC 86 Z9 87 U1 2 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP 1997 EP 2004 DI 10.1103/PhysRevB.55.1997 PG 8 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400022 ER PT J AU Hill, S Valfells, S Uji, S Brooks, JS Athas, GJ Sandhu, PS Sarrao, J Fisk, Z Goettee, J AF Hill, S Valfells, S Uji, S Brooks, JS Athas, GJ Sandhu, PS Sarrao, J Fisk, Z Goettee, J TI Quantum limit and anomalous field-induced insulating behavior in eta-Mo4O11 SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-WAVE INSTABILITIES; TRANSPORT-PROPERTIES; METAL ETA-MO4O11; MAGNETIC-FIELDS; OXIDES; TRANSITION; CRYSTALS; PRESSURE; MAGNETORESISTANCE; SUPERLATTICES AB The quasi-two-dimensional metal eta-Mo4O11 undergoes two successive charge-density-wave transitions at 109 and 30 K, with corresponding changes in the electronic structure. Measurements of the magnetoresistance, Hall effect, and magnetization, in magnetic fields of up to 50 T and as a function of temperature and pressure, have been performed to determine the ground-state electronic structure. Several distinct quantum oscillations are observed in the low-field magnetoresistance, corresponding to very small closed Fermi surfaces, all of which reach the quantum limit by 20 T. Analysis of the quantum oscillation amplitudes indicate very low carrier effective masses (m*<0.1m(e)) associated with each of the closed two-dimensional Fermi-surface pockets. At higher fields (B>20 T) we see a crossover from (semi-) metallic to semiconducting behavior, which we associate with a field-induced electron- and hole-band inversion, resulting in a clear gap at the Fermi-energy. Measurements of this energy gap allow an independent determination of the carrier effective masses, which are in excellent agreement with the values obtained from the analysis of the low-field (B<15 T) quantum oscillations. We find that the transport and thermodynamic properties of the field-induced insulating state are highly anomalous. In particular, we discuss the Hall effect and the origin of an additional quantum oscillation at high magnetic fields (B>20 T). C1 FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32310. BOSTON UNIV,DEPT PHYS,BOSTON,MA 02215. NATL RES INST MET,TSUKUBA,IBARAKI 305,JAPAN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NATL HIGH MAGNET FIELD LAB,LOS ALAMOS,NM 87545. RP Hill, S (reprint author), FLORIDA STATE UNIV,DEPT PHYS,TALLAHASSEE,FL 32310, USA. RI Hill, Stephen/J-5383-2014 OI Hill, Stephen/0000-0001-6742-3620 NR 51 TC 31 Z9 31 U1 0 U2 9 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP 2018 EP 2031 DI 10.1103/PhysRevB.55.2018 PG 14 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400024 ER PT J AU Fleszar, A Stumpf, R Eguiluz, AG AF Fleszar, A Stumpf, R Eguiluz, AG TI One-electron excitations, correlation effects, and the plasmon in cesium metal SO PHYSICAL REVIEW B LA English DT Article ID CALCULATED PHOTOEMISSION SPECTRA; ALKALI-METALS; BAND-STRUCTURE; NA; PSEUDOPOTENTIALS; DISPERSION; GAS; CS AB We study the dynamical electronic response of Cs at a first-principles level. The spatially localized 5p semicore shell induces a physical interplay between crystal local fields and electron correlations, leading to a novel, and relatively large, many-body shift of the plasmon energy. This effect, combined with that of one-electron transitions into empty states near the plasmon energy, yields a plasmon dispersion curve which is in excellent agreement with experiment for small wave vectors. In addition, our results feature a flat dispersion for large wave vectors, in qualitative agreement with experiment. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. SANDIA NATL LABS,DIV 1114,ALBUQUERQUE,NM 87185. MAX PLANCK GESELL,FRITZ HABER INST,D-14195 BERLIN,GERMANY. RP Fleszar, A (reprint author), UNIV WURZBURG,INST PHYS,HUBLAND,D-97074 WURZBURG,GERMANY. NR 34 TC 32 Z9 32 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP 2068 EP 2072 DI 10.1103/PhysRevB.55.2068 PG 5 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400028 ER PT J AU Ramirez, R Gonzalez, R Pareja, R Chen, Y AF Ramirez, R Gonzalez, R Pareja, R Chen, Y TI Semiconducting property of a wide-band-gap oxide crystal: Impact ionization and avalanche breakdown SO PHYSICAL REVIEW B LA English DT Article ID MGO SINGLE-CRYSTALS; P-TYPE GERMANIUM; DIELECTRIC-BREAKDOWN; HIGH-TEMPERATURES; RESONANCE; DEFECTS; CENTERS; LITHIUM;
  • 0; CAO AB It is shown that a wide band-gap crystal, appropriately doped, can exhibit semiconducting properties. When a de voltage was applied to a lithium-doped MgO single crystal containing [Li](0) centers, negative differential resistance, self-excited current oscillations, and filament-driven current were observed. The conductivity increase and the nonlinear behavior of the I-V characteristics are described by an impact ionization mechanism. Avalanche breakdown can be produced with low electric fields at moderate temperatures (similar to 373 K), which eventually leads to electrical breakdown. We postulate that filamentary semiconducting inclusions imbedded in the insulator matrix are responsible for the electrical degradation. C1 US DOE, DIV MAT SCI, OFF BASIC ENERGY SCI, GERMANTOWN, MD 20874 USA. RP Ramirez, R (reprint author), UNIV CARLOS III MADRID, DEPT FIS, ESCUELA POLITECN SUPER, LEGANES 28911, MADRID, SPAIN. RI Ramirez Jimenez, Rafael/I-1769-2015 NR 21 TC 13 Z9 13 U1 0 U2 5 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP 2413 EP 2416 DI 10.1103/PhysRevB.55.2413 PG 4 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400065 ER PT J AU Lambrecht, WRL Rashkeev, SN Segall, B LawniczakJablonska, K Suski, T Gullikson, EM Underwood, JH Perera, RCC Rife, JC Grzegory, I Porowski, S Wickenden, DK AF Lambrecht, WRL Rashkeev, SN Segall, B LawniczakJablonska, K Suski, T Gullikson, EM Underwood, JH Perera, RCC Rife, JC Grzegory, I Porowski, S Wickenden, DK TI X-ray absorption, glancing-angle reflectivity, and theoretical study of the N K- and Ga M(2,3)-edge spectra in GaN SO PHYSICAL REVIEW B LA English DT Article ID LIGHT-EMITTING-DIODES; ELECTRONIC-STRUCTURE; HEXAGONAL GAN; VALENCE-BAND; SPECTROSCOPY; GREEN; ALN AB A comprehensive study of the nitrogen K edge and gallium M(2,3) edge in gallium nitride is presented. Results of two different experimental techniques, x-ray absorption by total photocurrent measurements and glancing-angle x-ray reflectivity, are presented and compared with each other, First-principles calculations of the (polarization averaged) dielectric response epsilon(2)(omega) contributions from the relevant core-level to conduction-band transitions and derived spectral functions are used to interpret the data. These calculations are based on the local density approximation (LDA) and use a muffin-tin orbital basis for the band structure and matrix elements. The angular dependence of the x-ray reflectivity is studied and shown to be in good agreement with the theoretical predictions based on Fresnel theory and the magnitude of the calculated x-ray optical response functions. The main peaks in the calculated and measured spectra are compared with those in the relevant partial density of conduction-band states. Assignments are made to particular band transitions and corrections to the LDA are discussed. From the analysis of the N K and Ga M(2,3) edges the latter are found to be essentially constant up to similar to 10 eV above the conduction-band minimum. The differences in spectral shape found between the various measurements were shown to be a result of polarization dependence. Since the c axis in all the measurements was normal to the sample surface, p-polarized radiation at glancing angles corresponds to E parallel to c while s polarization corresponds to E perpendicular to e at all incident angles. Thus, this polarization dependence is a result of the intrinsic anisotropy of the wurtzite structure. Spectra on powders which provide an average of both polarizations as well as separate measurements of reflectivity with s polarization and p polarization were used to arrive at this conclusion. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. USN, RES LAB, WASHINGTON, DC 20375 USA. POLISH ACAD SCI, UNIPRESS, PL-01142 WARSAW, POLAND. JOHNS HOPKINS UNIV, APPL PHYS LAB, BALTIMORE, MD 20723 USA. PN LEBEDEV PHYS INST, MOSCOW 117924, RUSSIA. POLISH ACAD SCI, INST PHYS, PL-02668 WARSAW, POLAND. RP CASE WESTERN RESERVE UNIV, DEPT PHYS, CLEVELAND, OH 44106 USA. RI Lambrecht, Walter/O-1083-2016 NR 30 TC 35 Z9 35 U1 3 U2 14 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP 2612 EP 2622 DI 10.1103/PhysRevB.55.2612 PG 11 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400087 ER PT J AU Bales, GS Zangwill, A AF Bales, GS Zangwill, A TI Self-consistent rate theory of submonolayer homoepitaxy with attachment/detachment kinetics SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-BEAM EPITAXY; CRYSTAL-GROWTH; ISLAND GROWTH; NUCLEATION; SI(001); ENERGY; SIZES; VIEW AB The reversible nucleation and growth of two-dimensional islands during the submonolayer stage of epitaxial growth is studied with self-consistent rate equations and kinetic Monte Carlo simulations. In contrast to most previous work, we take account of the effects of both a finite energy barrier to the detachment of atoms from islands and a finite barrier to the incorporation of adatoms into islands. A correct boundary condition for the diffusion field at island edges is derived that takes account of these processes. For small detachment rates, quantitative agreement is obtained between the solutions to the rate theory and the simulations for the average monomer and island densities as a function of coverage. C1 GEORGIA INST TECHNOL,SCH PHYS,ATLANTA,GA 30332. RP Bales, GS (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 24 TC 82 Z9 83 U1 1 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP R1973 EP R1976 PG 4 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400017 ER PT J AU Burstein, L Shapira, Y Partee, J Shinar, J Lubianiker, Y Balberg, I AF Burstein, L Shapira, Y Partee, J Shinar, J Lubianiker, Y Balberg, I TI Surface photovoltage spectroscopy of porous silicon SO PHYSICAL REVIEW B LA English DT Article ID HYDROGENATED AMORPHOUS-SILICON; OPTICAL-PROPERTIES; BAND-GAP; PHOTOLUMINESCENCE; SI; LUMINESCENCE; ABSORPTION; INTERFACES; DEPENDENCE; SUBSTRATE AB Results of surface photovoltage spectroscopy on free-standing porous silicon films fabricated from boron-doped Si wafers of various resistivities are presented. We find that all the films have bandtails, which are about 0.3 eV wide, and their optical band gap is about 2 eV. The majority carriers in the strongly luminescent and poorly photoconducting films are holes, while in the weakly luminescent but photoconducting films they are electrons. This difference between the films appears to be due to different oxygen coverage of the silicon nanocrystallites. We conclude that the origin of the strong red-light luminescence is in the electron optical transitions from the conduction bandtail to the valence bandtail. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. RP Burstein, L (reprint author), TEL AVIV UNIV,DEPT ELECT ENGN,IL-89678 RAMAT AVIV,ISRAEL. NR 40 TC 39 Z9 39 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP R1930 EP R1933 PG 4 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400006 ER PT J AU Fernandez, P DalCorso, A Baldereschi, A Mauri, F AF Fernandez, P DalCorso, A Baldereschi, A Mauri, F TI First-principles Wannier functions of silicon and gallium arsenide SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; SYSTEM-SIZE; POLARIZATION; PSEUDOPOTENTIALS; SOLIDS; BANDS AB We present a self-consistent, real-space calculation of the Wannier functions of Si and GaAs within density-functional theory. We minimize the total-energy functional with respect to orbitals which behave as Wannier functions under crystal translations and, at the minimum, are orthogonal. The Wannier functions are used to calculate the total energy, lattice constant, bulk modulus, and the frequency of the zone-center TO phonon of the two semiconductors with the accuracy required in ab initio calculations. Furthermore, the centers of the Wannier functions are used to compute the macroscopic polarization of Si and GaAs in zero electric field. The effective charges of GaAs, obtained by finite differentiation of the polarization, agree with the results of linear-response theory. C1 UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. LAWRENCE BERKELEY LAB, DIV SCI MAT, BERKELEY, CA 94720 USA. RP Fernandez, P (reprint author), IRRMA, IN ECUBLENS, CH-1015 LAUSANNE, SWITZERLAND. RI Dal Corso, Andrea/A-5745-2008; mauri, francesco/K-5726-2012 OI mauri, francesco/0000-0002-6666-4710 NR 23 TC 16 Z9 16 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 JAN 15 PY 1997 VL 55 IS 4 BP R1909 EP R1913 PG 5 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400001 ER PT J AU Huang, DJ Reisfeld, G Strongin, M AF Huang, DJ Reisfeld, G Strongin, M TI Photoemission study of the transition from the insulating to metallic state in ultrathin layers SO PHYSICAL REVIEW B LA English DT Article ID SUPERCONDUCTIVITY; FILMS; LOCALIZATION; GAP AB The transition from the insulating to metallic state in ultrathin Pb films was studied using high-resolution photoemission. The states near E(F) were probed as Pb was deposited onto a thin insulating layer, thin enough to reduce macroscopic charging. The results, which experimentally show a vanishing of states at E(F), are consistent with the arguments of Efros and Shklovskii based on electron-electron interactions, and as far as we know are the first in situ study of the electronic properties as one goes from the insulating to metallic state in a two-dimensional system. RP Huang, DJ (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 17 TC 7 Z9 7 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0163-1829 J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1997 VL 55 IS 4 BP R1977 EP R1980 PG 4 WC Physics, Condensed Matter SC Physics GA WF124 UT WOS:A1997WF12400018 ER PT J AU Heckler, AF AF Heckler, AF TI Formation of a Hawking-radiation photosphere around microscopic black holes SO PHYSICAL REVIEW D LA English DT Article ID GAMMA-RAYS; TEMPERATURE AB We show that once a black hole surpasses some critical temperature T-crit, the emitted Hawking radiation interacts with itself and forms a nearly thermal photosphere. Using QED, we show that the dominant interactions are bremsstrahlung and electron-photon pair production, and we estimate T(crit)similar to m(e)/alpha(5/2), which when calculated more precisely is found to be T(crit)approximate to 45 GeV. The formation of the photosphere is purely a particle physics effect, and not a general relativistic effect, since the photosphere forms roughly alpha(-4) Schwarzschild radii away from the black hole. The temperature T of the photosphere decreases with distance from the black hole, and the outer surface is determined by the constraint T similar to m(e) (for the QED case), since this is the point at which electrons and positrons annihilate, and the remaining photons free stream to infinity. Observational consequences are discussed, and it is found that, although the QED photosphere will not affect the Page-Hawking limits on primordial black holes, which is most important for 100 MeV black holes, the inclusion of QCD interactions may significantly effect this limit, since for QCD we estimate T(crit)similar to Lambda(QCD). The photosphere greatly reduces the possibility of observing individual black holes with temperatures greater than T-crit, since the high energy particles emitted from the black hole are processed through the photosphere to a lower energy, where the gamma-ray background is much higher. The temperature of the plasma in the photosphere can be extremely high, and this offers interesting possibilities for processes such as symmetry restoration. RP Heckler, AF (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. RI Heckler, Andrew/A-7291-2010 OI Heckler, Andrew/0000-0001-5494-7855 NR 21 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 1997 VL 55 IS 2 BP 480 EP 488 DI 10.1103/PhysRevD.55.480 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF296 UT WOS:A1997WF29600008 ER PT J AU Semikoz, DV Tkachev, II AF Semikoz, DV Tkachev, II TI Condensation of bosons in the kinetic regime SO PHYSICAL REVIEW D LA English DT Article ID BOSE-EINSTEIN CONDENSATION; POLARIZED ATOMIC-HYDROGEN; POPULATION-DYNAMICS; SCALAR FIELDS; STARS; GAS; AXION; SCATTERING; SATURATION; EVOLUTION AB We study the kinetic regime of the Bose condensation of scalar particles. The Boltzmann equation is solved numerically. We consider two kinetic stages. At the first stage the condensate is absent but there is a nonzero inflow of particles towards p=0 and the distribution function at p=0 grows from finite values to infinity in a finite time. We observe a profound similarity between Bose condensation and Kolmogorov turbulence. At the second stage there are two components, the condensate and particles, reaching their equilibrium values. We show that the evolution in both stages proceeds in a self-similar way and find the time needed for condensation. We do not consider a phase transition from the first stage to the second. Condensation of self-interacting bosons is compared to the condensation driven by interaction with a cold gas of fermions; the latter turns out to be self-similar too. Exploiting the self-similarity we obtain a number of analytical results in all cases. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Semikoz, DV (reprint author), RUSSIAN ACAD SCI,INST NUCL RES,60TH OCTOBER ANNIVERSARY PROSPECT 7,MOSCOW 117312,RUSSIA. NR 58 TC 83 Z9 84 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 JAN 15 PY 1997 VL 55 IS 2 BP 489 EP 502 DI 10.1103/PhysRevD.55.489 PG 14 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF296 UT WOS:A1997WF29600009 ER PT J AU Abney, M AF Abney, M TI Fluctuations and bubble dynamics in first-order phase transitions SO PHYSICAL REVIEW D LA English DT Article ID SUBCRITICAL BUBBLES; FALSE VACUUM; FINITE-TEMPERATURE; BARYON ASYMMETRY; WALL VELOCITY; ELECTROWEAK; BARYOGENESIS; INSTABILITY; DIMENSIONS; EQUILIBRIUM AB We numerically examine the effect of thermal fluctuations on a first-order phase transition in (2 + 1) dimensions. By focusing on the expansion of a single bubble we are able to calculate changes in the bubble wall's velocity as well as changes in its structure relative to the standard case where the bubble expands into a homogeneous background. Not only does the wall move faster, but the transition from the symmetric to the asymmetric phase is no longer smooth, even for a fairly strong transition. We discuss how these results affect the standard picture of electroweak baryogenesis. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Abney, M (reprint author), UNIV CHICAGO,ENRICO FERMI INST,DEPT PHYS,CHICAGO,IL 60637, USA. NR 57 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 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 1997 VL 55 IS 2 BP 582 EP 594 DI 10.1103/PhysRevD.55.582 PG 13 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF296 UT WOS:A1997WF29600018 ER PT J AU Gaillard, MK Jain, V Saririan, K AF Gaillard, MK Jain, V Saririan, K TI Supergravity coupled to chiral matter at one loop .2. Chiral and Yang-Mills matter SO PHYSICAL REVIEW D LA English DT Article ID PAULI-VILLARS REGULARIZATION; STRING EFFECTIVE THEORIES; SUPERSYMMETRY BREAKING; LINEAR MULTIPLET; RADIATIVE-CORRECTIONS; ANOMALY CANCELLATION; FIELD-THEORIES; GAUGE; COUPLINGS; MODELS AB We present the full calculation of the divergent one-loop contribution to the effective boson Lagrangian for supergravity, including the Yang-Mills sector and the helicity-odd operators that arise from integration over fermion fields. The only restriction is on the Yang-Mills kinetic energy normalization function, which is taken diagonal in gauge indices, as in models obtained from superstrings. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. SUNY STONY BROOK,INST THEORET PHYS,STONY BROOK,NY 11794. RP Gaillard, MK (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720, USA. NR 46 TC 20 Z9 20 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 JAN 15 PY 1997 VL 55 IS 2 BP 883 EP 924 DI 10.1103/PhysRevD.55.883 PG 42 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF296 UT WOS:A1997WF29600048 ER PT J AU Turner, MS AF Turner, MS TI Detectability of inflation-produced gravitational waves SO PHYSICAL REVIEW D LA English DT Article ID TENSOR PERTURBATIONS; DENSITY PERTURBATIONS; BACKGROUND-RADIATION; UNIVERSE; ANISOTROPY; COBE; COSMOLOGY; MODELS; SCALE; FLUCTUATIONS AB Detection of the gravitational waves excited during inflation as quantum-mechanical fluctuations is a key test of inflation and crucial to learning about the specifics of the inflationary model. We discuss the potential of cosmic background radiation anisotropy and polarization and of laser interferometers such as LIGO, VIRGO, and LISA to detect these gravity waves. C1 FERMILAB NATL ACCELERATOR LAB, NASA, FERMILAB ASTROPHYS CTR, BATAVIA, IL 60615 USA. RP UNIV CHICAGO, ENRICO FERMI INST, 5640 S ELLIS AVE, CHICAGO, IL 60637 USA. NR 43 TC 70 Z9 70 U1 0 U2 1 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 JAN 15 PY 1997 VL 55 IS 2 BP R435 EP R439 DI 10.1103/PhysRevD.55.R435 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WF296 UT WOS:A1997WF29600001 ER PT J AU Muralidharan, G Petri, MC Epperson, JE Chen, HD AF Muralidharan, G Petri, MC Epperson, JE Chen, HD TI Interaction of Si and Al during interdiffusion in Ni-Al-Si alloys SO SCRIPTA MATERIALIA LA English DT Article C1 ARGONNE NATL LAB,IPNS,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV ENGN,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MAT SCI & ENGN,URBANA,IL 61801. RP Muralidharan, G (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Muralidharan, Govindarajan/J-6155-2015 NR 15 TC 6 Z9 6 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 15 PY 1997 VL 36 IS 2 BP 219 EP 225 DI 10.1016/S1359-6462(96)00362-4 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VY359 UT WOS:A1997VY35900012 ER PT J AU Hsiung, LM Nieh, TG Clemens, DR AF Hsiung, LM Nieh, TG Clemens, DR TI Effect of extrusion temperature on the microstructure of a powder metallurgy TiAl-based alloy SO SCRIPTA MATERIALIA LA English DT Article ID TRANSFORMATIONS C1 PRATT & WHITNEY AIRCRAFT,ADV ENGN OPERAT,W PALM BEACH,FL 33410. RP Hsiung, LM (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L-370,LIVERMORE,CA 94551, USA. RI Nieh, Tai-Gang/G-5912-2011 OI Nieh, Tai-Gang/0000-0002-2814-3746 NR 13 TC 8 Z9 8 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 15 PY 1997 VL 36 IS 2 BP 233 EP 238 DI 10.1016/S1359-6462(96)00353-3 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA VY359 UT WOS:A1997VY35900014 ER PT J AU Pichahchy, AE Cremers, DA Ferris, MJ AF Pichahchy, AE Cremers, DA Ferris, MJ TI Elemental analysis of metals under water using laser-induced breakdown spectroscopy SO SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY LA English DT Article DE laser-induced breakdown spectroscopy; laser spark; elemental analysis; underwater elemental analysis ID SPECTROCHEMICAL ANALYSIS; EMISSION-SPECTROSCOPY; CAVITATION BUBBLES; CONFINED GEOMETRY; PLASMA; COLLAPSE; LIQUIDS; SAMPLES; SYSTEM; SPARK AB Laser-induced breakdown spectroscopy (LIBS) has been evaluated for the detection of metals located under water. Repetitive laser sparks were formed on the metals by focused pulses from a Q-switched Nd:YAG laser (1064 nm). Using repetitive single sparks (RSS) at 10 Hz, only weak elemental emission signals were generated from even strongly emitting species at high concentrations (e.g. Al(I) from commercially pure aluminum). The spectrum in these cases was dominated by spectrally broad emissions (continuum radiation) from the plume (T < 3000 K). The use of a repetitive spark pair (RSP), however, produced a plasma (T similar to 8,880 K) on the second pulse useful to monitor the elemental composition of the metals. In the RSP, a pair of pulses was focused on the metals at 10 Hz with the separation between pulses adjusted from 30 to 180 mu s. The pulse pair was generated from a single laser. Only a weak dependence of the emission intensities on the separation between the pulses of the spark pair was observed although signal enhancements over two orders of magnitude were obtained compared to the RSS. Using the RSP, detection limits of 367, 520, 1200, and 1190 ppm were obtained for Cr, Cu, Mn, and Si in steel. Using time-resolved imaging of the laser plumes/plasmas plasmas formed on the metal samples under water, some characteristics of the excitation process were evaluated. It was determined that the first pulse of the RSP forms a large bubble or vapor cavity (maximum diameter similar to 8 mm) on the metal surface which is then interrogated by the second pulse. The second pulse then forms a plasma resulting in excitation similar to that produced by a single laser spark formed on metal in air. (C) 1997 Elsevier Science B.V. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV MSJ565,GRP CST1,LOS ALAMOS,NM 87545. NR 33 TC 148 Z9 148 U1 4 U2 44 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0584-8547 J9 SPECTROCHIM ACTA B JI Spectroc. Acta Pt. B-Atom. Spectr. PD JAN 15 PY 1997 VL 52 IS 1 BP 25 EP 39 DI 10.1016/S0584-8547(96)01575-3 PG 15 WC Spectroscopy SC Spectroscopy GA WK861 UT WOS:A1997WK86100003 ER PT J AU Renaudin, CD Troedsson, MHT Gillis, CL King, VL Bodena, A AF Renaudin, CD Troedsson, MHT Gillis, CL King, VL Bodena, A TI Ultrasonographic evaluation of the equine placenta by transrectal and transabdominal approach in the normal pregnant mare SO THERIOGENOLOGY LA English DT Article DE mare; pregnancy; placenta; ultrasonography ID ULTRASOUND AB The objective of this study was to determine normal variations in the utero placental thickness during mid- and late gestation in the mate. Normal, healthy pregnant mares (n=9) were examined monthly from 4 mo of gestation until parturition by transrectal and transabdominal ultrasonography. At each examination, the combined thickness of the uterus and the placenta (CTUP) was measured at the placento-cervical junction (transrectally) and at the uterine body or the uterine horns (transabdominally). In addition, the echogenicity of the amniotic and allantoic fluids was evaluated by transrectal ultrasonography. Following parturition and expulsion of the fetal membranes, the allantochorion was measured and visually examined for abnormalities. At all examinations, both transrectal and transabdominal, the chorioallantois and the uterus were indistinguishable from each other on the ultrasound image. The CTUP, measured by transrectal ultrasonography did not change between 4 and 8 mo of gestation, but increased significantly for each month between 10 and 12 mo of gestation (P<0.001). A change in the CTUP was detected between months when measured by transabdominal ultrasonography, but no distinct pattern in these changes was observed. No correlation was found between transabdominal and transrectal measurements of the CTUP. The echogenicity of the amniotic and allantoic fluids did not consistently change over time during mid- and late gestation. The amniotic fluid was more echogenic than the allantoic fluid at most examinations from 6 mo of pregnancy and throughout gestation (P<0.05). It was concluded that transrectal ultrasonographic examination to assess the CTUP and the echogenicity of the fetal fluids is superior to the transabdominal approach. We suggest that transrectal ultrasonographic examination should be added to current diagnostic tools during late gestation and that it be part of the biophysical profile of high risk equine pregnancies. (C) 1997 by Elsevier Science Inc. C1 UNIV MINNESOTA,COLL VET MED,DEPT CLIN & POPULAT SCI,ST PAUL,MN 55108. LAWRENCE LIVERMORE NATL LAB,VET MED TEACHING HOSP,DEPT EQUINE REPROD,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT SURG & RADIOL SCI,DAVIS,CA 95616. NR 24 TC 62 Z9 64 U1 3 U2 13 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0093-691X J9 THERIOGENOLOGY JI Theriogenology PD JAN 15 PY 1997 VL 47 IS 2 BP 559 EP 573 DI 10.1016/S0093-691X(97)00014-9 PG 15 WC Reproductive Biology; Veterinary Sciences SC Reproductive Biology; Veterinary Sciences GA WH485 UT WOS:A1997WH48500014 PM 16728008 ER PT J AU Bedrossian, PJ Caturla, MJ delaRubia, TD AF Bedrossian, PJ Caturla, MJ delaRubia, TD TI Damage evolution and surface defect segregation in low-energy ion-implanted silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID SIMULATION AB We have combined computer simulations and atomic-resolution tunneling microscopy to investigate the kinetics of defect migration during annealing of ion implanted Si(III)-7x7, Using atomically-clean and flat surfaces as sinks for bulk point defects introduced by the irradiation, we observe distinct, temperature-dependent surface arrival rates for vacancies and interstitials and we demonstrate that the distinct kinetics of each type of bulk point defect govern their surface segregation kinetics. A combination of simulation tools provides a detailed description of the processes that underlie the observed temperature-dependence of defect migration. (C) 1997 American Institute of Physics. RP LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RI Caturla, Maria /D-6241-2012 OI Caturla, Maria /0000-0002-4809-6553 NR 15 TC 30 Z9 30 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 13 PY 1997 VL 70 IS 2 BP 176 EP 178 DI 10.1063/1.118349 PG 3 WC Physics, Applied SC Physics GA WC058 UT WOS:A1997WC05800012 ER PT J AU Curro, JG Honnell, KG McCoy, JD AF Curro, JG Honnell, KG McCoy, JD TI Theory for the solubility of gases in polymers: Application to monatomic solutes SO MACROMOLECULES LA English DT Article ID INTEGRAL-EQUATION THEORY; POLYETHYLENE MELTS; THERMODYNAMICS; BLENDS; SORPTION; LIQUIDS; PARAMETER; FLUIDS; CHAINS AB The polymer reference interaction site model (PRISM theory) is applied to the problem of calculating the solubility of monatomic gases in amorphous polyethylene. One can consider this system as an approximation to the solubility of gases in ethylene/propylene elastomers. The chemical potential of a solute atom in the polymer is decomposed into two distinct contributions: a positive athermal contribution calculated by growing the solute atom from a point particle and a negative attractive contribution computed from first-order perturbation theory using the athermal system as the reference state. Good agreement is found between the PRISM calculations and available experimental data on solubility of gases in common elastomers with no adjustable parameters. Furthermore, PRISM theory is successful in predicting several interesting trends observed experimentally: (1) solubility increases with the size of the solute atom, (2) solubility is a monotonically increasing function of the critical temperature of the solute species, and (3) the temperature coefficient of solubility crosses over from positive to negative for solutes having critical temperatures of approximately 65 K. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NEW MEXICO INST MIN & TECHNOL,DEPT MAT & MET ENGN,SOCORRO,NM 87801. RP Curro, JG (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. RI McCoy, John/B-3846-2010 OI McCoy, John/0000-0001-5404-1404 NR 33 TC 18 Z9 18 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD JAN 13 PY 1997 VL 30 IS 1 BP 145 EP 152 DI 10.1021/ma961084s PG 8 WC Polymer Science SC Polymer Science GA WC683 UT WOS:A1997WC68300021 ER PT J AU Myers, WD Swiatecki, WJ AF Myers, WD Swiatecki, WJ TI The congruence energy: A contribution to nuclear masses, deformation energies and fission barriers SO NUCLEAR PHYSICS A LA English DT Article ID STATE AB The difference between measured binding energies and those calculated using a shell- and pairing-corrected Thomas-Fermi model can be described approximately by C(I) = - 10 exp(- 4.2 / I /) MeV, where I = (N - Z)/A. Our interpretation of this extra binding is in terms of the granularity of quantal nucleonic density distributions, which leads to a stronger interaction for a neutron and proton with congruent nodal structures of their wave functions. The predicted doubling of this congruence energy in fission is supported by an analysis of measured fission barriers and by a study of wave functions in a dividing Hill-Wheeler box potential. A semi-empirical formula for the shape-dependent congruence energy is described. RP Myers, WD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 14 TC 78 Z9 78 U1 1 U2 2 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 JAN 13 PY 1997 VL 612 IS 2 BP 249 EP 261 DI 10.1016/S0375-9474(96)00328-4 PG 13 WC Physics, Nuclear SC Physics GA WD117 UT WOS:A1997WD11700007 ER PT J AU Mattiuzzi, M Bracco, A Camera, F Ormand, WE Gaardhoje, JJ Maj, A Million, B Pignanelli, M Tveter, T AF Mattiuzzi, M Bracco, A Camera, F Ormand, WE Gaardhoje, JJ Maj, A Million, B Pignanelli, M Tveter, T TI Angular momentum dependence of the GDR width in Sn nuclei at fixed excitation energy SO NUCLEAR PHYSICS A LA English DT Article DE Ti-48(Ni-56,xn), E(gamma), I-gamma BaF2, PPAC's and multiplicity filter detectors; Sn-106 deduced giant dipole resonance width ID GIANT-DIPOLE-RESONANCE; HOT ROTATING NUCLEI; THERMAL FLUCTUATIONS; FINITE TEMPERATURE; SHAPE FLUCTUATIONS; PHOTONS AB High-energy gamma-rays from the decay of the giant-dipole resonance (GDR) in the hot Sn-106 compound nucleus and its daughters were measured in coincidence with heavy recoiling evaporation residues. The compound nucleus was formed at excitation energy E* = 80 MeV using the reaction Ni-56 + Ti-48 at a bombarding energy of 260 MeV. The analysis yields the GDR width for two different intervals of angular momentum [J] = 24 and 36(h) over bar. The present data, combined with previous data at higher angular momentum permit a study of the angular momentum dependence of the GDR width for 10 less than or equal to J less than or equal to 60(h) over bar at approximately fixed temperature. The width of the GDR is found to be roughly constant for J < 35(h) over bar, increasing rapidly for higher angular momenta. The data are found to be in good agreement with theoretical calculations within an adiabatic model describing thermal fluctuations of the nuclear shape. The model also reproduces the much weaker angular momentum dependence of the GDR width in the heavier nucleus W-176. C1 IST NAZL FIS NUCL,I-20133 MILAN,ITALY. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. NIELS BOHR INST,DK-2100 COPENHAGEN O,DENMARK. H NIEWODNICZANSKI INST NUCL PHYS,PL-31342 KRAKOW,POLAND. UNIV OSLO,BLINDERN,NORWAY. UNIV MILAN,POLO DIDATT & RIC CREMA,CREMA,ITALY. RP Mattiuzzi, M (reprint author), UNIV MILAN,DIPARTIMENTO FIS,VIA CELORIA 16,I-20133 MILAN,ITALY. NR 38 TC 66 Z9 66 U1 1 U2 2 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 JAN 13 PY 1997 VL 612 IS 2 BP 262 EP 278 DI 10.1016/S0375-9474(97)80016-4 PG 17 WC Physics, Nuclear SC Physics GA WD117 UT WOS:A1997WD11700008 ER PT J AU Cai, D Bishop, AR GronbechJensen, N Malomed, BA AF Cai, D Bishop, AR GronbechJensen, N Malomed, BA TI Dark shock waves in the nonlinear Schrodinger system with internal losses SO PHYSICAL REVIEW LETTERS LA English DT Article ID OPTICAL FIBERS; MARGINAL STABILITY; PROPAGATION; MODULATION; SELECTION; PULSES; FRONTS; MEDIA AB We demonstrate that the (1 + 1) dimensional, normal-dispersion, nonlinear Schrodinger equation with an ''internal viscosity'' has a stable ''dark'' shock wave (SW) solution, which is the invasion of the empty (dark) domain into the energy-carrying one. It may be interpreted as an optical SW in a loss-compensated nonlinear optical fiber. We predict that it can be created experimentally with a temporal width of a few picoseconds at a carrier-wave background power about 10 W. We develop a theoretical analysis that captures the physics of the SW propagation. The prediction that the SW velocity has a constant value in the limit of small viscosity, and scales as the square root of the viscosity in the large viscosity limit, are confirmed by the full dynamics simulations. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. TEL AVIV UNIV,SCH MATH SCI,DEPT MATH APPL,IL-69978 TEL AVIV,ISRAEL. RP Cai, D (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 24 TC 23 Z9 23 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 JAN 13 PY 1997 VL 78 IS 2 BP 223 EP 226 DI 10.1103/PhysRevLett.78.223 PG 4 WC Physics, Multidisciplinary SC Physics GA WU310 UT WOS:A1997WU31000016 ER PT J AU Tersoff, J Johnson, MD Orr, BG AF Tersoff, J Johnson, MD Orr, BG TI Adatom densities on GaAs: Evidence for near-equilibrium growth SO PHYSICAL REVIEW LETTERS LA English DT Article ID ENERGY ELECTRON-DIFFRACTION; VICINAL GAAS(001); EPITAXIAL-GROWTH; DEPENDENCE AB We examine the equilibrium of a compound semiconductor surface under molecular beam epitaxy (MBE) conditions, both theoretically and experimentally. For GaAs, the Ga chemical potential and adatom density depend sensitively on As pressure as well as temperature. Our results suggest that MBE growth may take place under conditions much closer to equilibrium than has been believed. We also show that standard one-component models cannot, even in principle, reproduce both the adatom density and its temperature dependence. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV MICHIGAN,HARRISON M RANDALL LAB,ANN ARBOR,MI 48109. RP Tersoff, J (reprint author), IBM CORP,THOMAS J WATSON RES CTR,POB 218,YORKTOWN HTS,NY 10598, USA. NR 12 TC 94 Z9 95 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 JAN 13 PY 1997 VL 78 IS 2 BP 282 EP 285 DI 10.1103/PhysRevLett.78.282 PG 4 WC Physics, Multidisciplinary SC Physics GA WU310 UT WOS:A1997WU31000031 ER PT J AU Tranquada, JM Axe, JD Ichikawa, N Moodenbaugh, AR Nakamura, Y Uchida, S AF Tranquada, JM Axe, JD Ichikawa, N Moodenbaugh, AR Nakamura, Y Uchida, S TI Coexistence of, and competition between, superconductivity and charge-stripe order in La1.6-xNd0.4SrxCuO4 SO PHYSICAL REVIEW LETTERS LA English DT Article ID T-J MODEL; LA2-XSRXCUO4; LA1.85SR0.15CUO4; APPROXIMATION; INSTABILITIES; FLUCTUATIONS; SCATTERING; DYNAMICS AB Previously we have presented evidence for stripe order of holes and spins in La1.6-xNd0.4SrxCuO4 with x = 0.12. Here we show, via neutron diffraction measurements of magnetic scattering that similar order occurs in crystals with x = 0.15 and 0.20. Zero-field-cooled magnetization measurements show that all three compositions are also superconducting, with the superconducting transition temperature increasing as the low-temperature staggered magnetization decreases. These results directly demonstrate an intimate connection between stripe correlations and superconductivity. C1 UNIV TOKYO,DEPT SUPERCONDUCT,BUNKYO KU,TOKYO 113,JAPAN. RP Tranquada, JM (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. RI Tranquada, John/A-9832-2009; Nakamura, Yasunobu/H-1300-2012; OI Tranquada, John/0000-0003-4984-8857; Moodenbaugh, Arnold/0000-0002-3415-6762 NR 33 TC 555 Z9 556 U1 3 U2 22 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 JAN 13 PY 1997 VL 78 IS 2 BP 338 EP 341 DI 10.1103/PhysRevLett.78.338 PG 4 WC Physics, Multidisciplinary SC Physics GA WU310 UT WOS:A1997WU31000045 ER PT J AU Martin, JE Odinek, J AF Martin, JE Odinek, J TI Aggregation, fragmentation, and the nonlinear dynamics of electrorheological fluids in oscillatory shear - Reply SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORCES RP Martin, JE (reprint author), SANDIA NATL LABS,DIV ADV MAT PHYS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 0 Z9 0 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 JAN 13 PY 1997 VL 78 IS 2 BP 397 EP 397 DI 10.1103/PhysRevLett.78.397 PG 1 WC Physics, Multidisciplinary SC Physics GA WU310 UT WOS:A1997WU31000062 ER PT J AU Rothman, T Anninos, P AF Rothman, T Anninos, P TI Hamiltonian dynamics and the entropy of the gravitational field SO PHYSICS LETTERS A LA English DT Article ID ISOTROPIC SINGULARITIES; BLACK-HOLES AB We take a statistical mechanics approach to investigate the function S = ln Omega as a possible ''gravitational entropy'', where Omega is the phase-space volume bounded by a Hamiltonian H. We calculate Omega for several cosmological models, attributing entropy to a lack of knowledge in the exact field configuration. We also compare our results with Penrose's C-2 hypothesis and the Bekenstein-Hawking entropy for black holes. C1 UNIV ILLINOIS,NATL CTR SUPERCOMP APPLICAT,URBANA,IL 61801. RP Rothman, T (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 12 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JAN 13 PY 1997 VL 224 IS 4-5 BP 227 EP 233 DI 10.1016/S0375-9601(96)00841-9 PG 7 WC Physics, Multidisciplinary SC Physics GA WD160 UT WOS:A1997WD16000003 ER PT J AU Zharnitsky, V AF Zharnitsky, V TI Resonances in a continuously forced anharmonic oscillator SO PHYSICS LETTERS A LA English DT Article AB Periodically forced motion of a classical particle in a one-dimensional potential with superquadratic growth at infinity is considered. It is shown that an arbitrary amount of energy can be transmitted to the oscillator by exciting the system with a continuous time-periodic forcing. This result extends Littlewood's example of unbounded motions in the presence of a discontinuous periodic forcing and, thus, sheds tight on the relation between the smoothness of forcing and the stability of motion. A new version of the averaging procedure, which had to be applied to justify the construction, is outlined. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Zharnitsky, V (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JAN 13 PY 1997 VL 224 IS 4-5 BP 264 EP 270 DI 10.1016/S0375-9601(96)00833-X PG 7 WC Physics, Multidisciplinary SC Physics GA WD160 UT WOS:A1997WD16000009 ER PT J AU Davis, RA Gingrich, DM Pinfold, JL Rodning, NL Boos, E Zhautykov, BO Aubert, B Bazan, A Beaugiraud, B Boniface, J Colas, J Eynard, G Jezequel, S Leflour, T Linossier, O Nicoleau, S Rival, F Sauvage, G Thion, J VanDenPlas, D WingerterSeez, I Zitoun, R Zolnierowski, YP Chmeissani, M Fernandez, E Garrido, L Martinez, M Padilla, C Gordon, HA Radeka, V Rahm, D Stephani, D Baisin, L Berset, JC Chevalley, JL Gianotti, F Vuillemin, V Gildemeister, O Marin, CP Nessi, M Poggioli, L Richter, W Baze, JM Gosset, L Lavocat, P Lottin, JP Mansoulie, B Meyer, JP Teiger, J Collot, J deSaintignon, P Dzahini, D Renardy, JF Schwindling, J Hostachy, JY Hoummada, A Cousinou, MC Dargent, P Dinkespiller, B Etienne, F Fassnacht, P Fouchez, D Martin, L Miotto, A Monnier, E Nagy, E Olivetto, C Tisserant, S Battistoni, G Camin, DV Cavalli, D Costa, G Cozzi, L Fedyakin, N Ferrari, A Mandelli, L Mazzanti, M Perini, L Resconi, S Sala, P Beaudoin, G Depommier, P LeonFlorian, E Leroy, C Roy, P Auge, E Chase, R Chollet, JC delaTaille, C Fayard, L Fournier, D Hrisoho, A Merkel, B Noppe, JM Parrour, G Petroff, P Schaffer, A SeguinMoreau, N Serin, L Tisserand, V Vichou, I Canton, B David, J Genat, JF Imbault, D LeDortz, O SavoyNavarro, A Schwemling, P Eek, LO LundJensen, B Soderqvist, J Lefebvre, M Robertson, S AF Davis, RA Gingrich, DM Pinfold, JL Rodning, NL Boos, E Zhautykov, BO Aubert, B Bazan, A Beaugiraud, B Boniface, J Colas, J Eynard, G Jezequel, S Leflour, T Linossier, O Nicoleau, S Rival, F Sauvage, G Thion, J VanDenPlas, D WingerterSeez, I Zitoun, R Zolnierowski, YP Chmeissani, M Fernandez, E Garrido, L Martinez, M Padilla, C Gordon, HA Radeka, V Rahm, D Stephani, D Baisin, L Berset, JC Chevalley, JL Gianotti, F Vuillemin, V Gildemeister, O Marin, CP Nessi, M Poggioli, L Richter, W Baze, JM Gosset, L Lavocat, P Lottin, JP Mansoulie, B Meyer, JP Teiger, J Collot, J deSaintignon, P Dzahini, D Renardy, JF Schwindling, J Hostachy, JY Hoummada, A Cousinou, MC Dargent, P Dinkespiller, B Etienne, F Fassnacht, P Fouchez, D Martin, L Miotto, A Monnier, E Nagy, E Olivetto, C Tisserant, S Battistoni, G Camin, DV Cavalli, D Costa, G Cozzi, L Fedyakin, N Ferrari, A Mandelli, L Mazzanti, M Perini, L Resconi, S Sala, P Beaudoin, G Depommier, P LeonFlorian, E Leroy, C Roy, P Auge, E Chase, R Chollet, JC delaTaille, C Fayard, L Fournier, D Hrisoho, A Merkel, B Noppe, JM Parrour, G Petroff, P Schaffer, A SeguinMoreau, N Serin, L Tisserand, V Vichou, I Canton, B David, J Genat, JF Imbault, D LeDortz, O SavoyNavarro, A Schwemling, P Eek, LO LundJensen, B Soderqvist, J Lefebvre, M Robertson, S TI Construction and test of a fine-grained liquid argon preshower prototype SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PERFORMANCE; CALORIMETER AB A separate liquid argon preshower detector consisting of two layers featuring a fine granularity of 2.5 x 10(-3) was studied by the RD3 collaboration. A prototype covering approximately 0.8 in pseudo-rapidity and 9 degrees in azimuth was built and tested at CERN in July 94. CMOS and GaAs VLSI preamplifiers were designed and tested for this occasion. The combined response of this detector and an accordion electromagnetic calorimeter prototype to muons, electrons and photons is presented. For minimum ionizing tracks a signal-to-noise ratio of 4.5 per preshower layer was measured. Above 150 GeV the space resolution for electrons is better than 250 mu m in both directions. The precision on the electromagnetic shower direction, determined together with the calorimeter, is better than 4 mrad above 50 GeV. It is concluded that the preshower detector would adequately fulfil its role for future operation at CERN Large Hadron Collider. C1 UNIV GRENOBLE 1,IN2P3,ISN,F-38041 GRENOBLE,FRANCE. UNIV ALBERTA,EDMONTON,AB T6G 2M7,CANADA. HEPI,ALMA ATA,KAZAKHSTAN. LAPP,ANNECY,FRANCE. UNIV AUTONOMA BARCELONA,BELLATERRA,SPAIN. BROOKHAVEN NATL LAB,UPTON,NY 11973. CERN,CH-1211 GENEVA 23,SWITZERLAND. CEA SACLAY,SPP,DAPNIA,DSM,F-91191 GIF SUR YVETTE,FRANCE. UNIV AUTONOMA MADRID,E-28049 MADRID,SPAIN. CPP,MARSEILLE,FRANCE. UNIV MILAN,DIPARTIMENTO FIS,MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. UNIV MONTREAL,MONTREAL,PQ H3C 3J7,CANADA. LAL,ORSAY,FRANCE. UNIV PARIS 06,LPNHE,PARIS,FRANCE. UNIV PARIS 07,PARIS,FRANCE. ROYAL INST TECHNOL,S-10044 STOCKHOLM,SWEDEN. UNIV VICTORIA,VICTORIA,BC V8W 2Y2,CANADA. TRIUMF,VANCOUVER,BC V6T 2A3,CANADA. FAC SCI,CASABLANCA,MOROCCO. RI Boos, Eduard/D-9748-2012; sala, paola/E-2868-2013; Chmeissani, Mokhtar/G-4346-2015; Fernandez, Enrique/L-5387-2014 OI sala, paola/0000-0001-9859-5564; Chmeissani, Mokhtar/0000-0002-2287-4791; Fernandez, Enrique/0000-0002-6405-9488 NR 14 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 1997 VL 385 IS 1 BP 47 EP 57 DI 10.1016/S0168-9002(96)01037-6 PG 11 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WE741 UT WOS:A1997WE74100008 ER PT J AU Gatley, SJ Volkow, ND Gifford, AN Ding, YS Logan, J Wang, GJ AF Gatley, SJ Volkow, ND Gifford, AN Ding, YS Logan, J Wang, GJ TI Model for estimating dopamine transporter occupancy and subsequent increases in synaptic dopamine using positron emission tomography and carbon-11-labeled cocaine SO BIOCHEMICAL PHARMACOLOGY LA English DT Article DE cocaine; dopamine transport; drug abuse; methylphenidate; positron emission tomography (PET); pharmacotherapy ID HUMAN-BRAIN; RAT STRIATUM; IN-VIVO; UPTAKE SITES; H-3 COCAINE; SEROTONIN TRANSPORTERS; GBR-12935 BINDING; PARKINSONS-DISEASE; NUCLEUS-ACCUMBENS; CAUDATE-NUCLEUS AB Although increases in dopamine secondary to the inhibition of the dopamine transporter appear to underlie the reinforcing properties of cocaine, there is presently no model that relates the elevation of synaptic dopamine to the transporter occupancy by cocaine. We propose such a model based on positron emission tomographic (PET) measurements of the brain concentration of cocaine and the assumption of rapid equilibrium between free cocaine and cocaine bound to the dopamine transporter. A euphorigenic dose of cocaine (about 40 mg) is predicted to occupy 80-90% of the transporters, while a perceptible dose (about 5 mg) occupies about 40% of the transporters. If reuptake of dopamine is reduced in proportion to the fraction of transporters occupied by cocaine, our model indicates that synaptic dopamine rises supra-linearly with occupancy, so that 5 and 40 mg doses of cocaine give about 2- and 10-fold increases, respectively. A consequence is that a given dose of cocaine produces a similar degree of elevation of dopamine regardless of the prior level of occupation of the transporters by cocaine. This prediction is supported by recent PET/neuropsychological studies in our laboratory where dopamine transporter occupancy was measured after giving methylphenidate intravenously to volunteers; similarly intense ''highs'' were reported whether the initial occupancy was zero or 75-85%. It could also explain why attempts to block the psychostimulant-induced ''high'' by pretreating subjects with drugs that block the dopamine transporter have been unsuccessful, and why the use of methylphenidate to treat cocaine addicts led to increased cocaine consumption. Copyright (C) 1996 Elsevier Science Inc. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Gatley, SJ (reprint author), BROOKHAVEN NATL LAB,DEPT MED,490 BELL AVE,UPTON,NY 11973, USA. FU NIDA NIH HHS [DA09490, DA 06278] NR 71 TC 27 Z9 28 U1 4 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0006-2952 J9 BIOCHEM PHARMACOL JI Biochem. Pharmacol. PD JAN 10 PY 1997 VL 53 IS 1 BP 43 EP 52 DI 10.1016/S0006-2952(96)00655-7 PG 10 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA VX361 UT WOS:A1997VX36100007 PM 8960062 ER PT J AU Takahashi, K Jonah, CD AF Takahashi, K Jonah, CD TI The measurement of an electron transfer reaction in a non-polar supercritical fluid SO CHEMICAL PHYSICS LETTERS LA English DT Article ID REORGANIZATION ENERGY; SOLVATION DYNAMICS; CARBON-DIOXIDE; ETHANE; FLUORESCENCE; TEMPERATURE; DEPENDENCE; PRESSURE; BEHAVIOR; EQUATION AB The intermolecular electron transfer reaction between a biphenyl anion and pyrene in supercritical ethane was studied using pulse radiolysis. Second-order electron transfer rates were found to be of the order of 10(11) M(-1) s(-1). The rate constants appear to be approximately constant over the pressure range 55-133 bar. Two possibilities are discussed that could explain the present results: solvent clustering, or a dependence of the solvent reorganization energy on pressure. Reorganization energies of non-polar supercritical ethane were estimated from the observed rate constant using the modified Marcus equation. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Takahashi, K (reprint author), HOKKAIDO UNIV,FAC ENGN,NORTH 13,WEST 8,SAPPORO,HOKKAIDO 060,JAPAN. RI Takahashi, Kenji/C-8846-2011; Takahashi, Kenji/F-4885-2014 NR 34 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 10 PY 1997 VL 264 IS 3-4 BP 297 EP 302 DI 10.1016/S0009-2614(96)01338-3 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD049 UT WOS:A1997WD04900007 ER PT J AU Grannan, SM Birmingham, JT Richards, PL Bethune, DS deVries, MS vanLoosdrecht, PHM Dorn, HC Burbank, P Bailey, J Stevenson, S AF Grannan, SM Birmingham, JT Richards, PL Bethune, DS deVries, MS vanLoosdrecht, PHM Dorn, HC Burbank, P Bailey, J Stevenson, S TI Far infrared transmittance of Sc-2@C-84 and Er-2@C-82 SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PREDICTION; FULLERENES; SEPARATION; COMPLEXES; SPECTRUM; METALS; LAC82; C-82; C82; EPR AB We have measured the far infrared transmittance of Sc-2@C-84 and Er-2@C-82 at 1.5 K between 30 and 200 cm(-1). Both materials are observed to have a large primary absorption feature centered at 95 cm(-1) with a width of approximately 50 cm(-1), as well as a number of secondary absorption features which are different in the two materials, This is the first study of the far infrared properties of metallofullerenes and may help in the determination of the structural and electronic properties of these materials. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. IBM CORP,DIV RES,ALMADEN RES CTR,SAN JOSE,CA 95120. VIRGINIA POLYTECH INST & STATE UNIV,DEPT CHEM,BLACKSBURG,VA 24061. RP Grannan, SM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720, USA. RI van Loosdrecht, Paul/F-7670-2011; Dorn, Harry/K-6830-2013 NR 26 TC 18 Z9 18 U1 0 U2 0 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 JAN 10 PY 1997 VL 264 IS 3-4 BP 359 EP 365 DI 10.1016/S0009-2614(96)01313-9 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD049 UT WOS:A1997WD04900017 ER PT J AU Miranda, PB Pflumio, V Saijo, H Shen, YR AF Miranda, PB Pflumio, V Saijo, H Shen, YR TI Conformation of surfactant monolayers at solid/liquid interfaces SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SUM-FREQUENCY GENERATION; LIQUID-VAPOR INTERFACE; VIBRATIONAL SPECTROSCOPY; HYDROPHOBIC SURFACE; MOLECULAR-DYNAMICS; FREE-ENERGY; WATER; PHASE; THERMODYNAMICS; ORIENTATION AB Infrared-visible sum-frequency (SFG) vibrational spectroscopy is used to study chain conformation of cationic surfactant monolayers (dioctadecyl dimethyl ammonium chloride, DOAC), adsorbed at various quartz/liquid interfaces at low coverage. The results show that the chains can assume many different conformations: an all-trans form if the liquid is alkane with a similarly long chain length, a bent form with significant trans-gauche defects if the liquid is CCL(4) or CDCL(3) or short-chain alkanes, and a highly contracted form if the liquid is water or alcohol. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Miranda, PB (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Miranda, Paulo/C-5933-2012 OI Miranda, Paulo/0000-0002-2890-0268 NR 35 TC 35 Z9 36 U1 1 U2 14 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 JAN 10 PY 1997 VL 264 IS 3-4 BP 387 EP 392 DI 10.1016/S0009-2614(96)01327-9 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD049 UT WOS:A1997WD04900022 ER PT J AU Shkrob, IA AF Shkrob, IA TI On the mechanism of multiplet CIDEP in radical ion pairs SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DYNAMIC ELECTRON POLARIZATION; DETECTED MAGNETIC-RESONANCE; PHOTOOXIDATION REACTIONS; EXCHANGE INTERACTIONS; SPIN RESONANCE; RECOMBINATION; SYSTEMS; PHOTOIONIZATION; PHOTOLYSIS; TRIPLET AB It is shown that multiplet chemically induced dynamic electron polarization (CIDEP) in radical ion pairs is unlikely to be caused by electron spin exchange (J), unless the rate of electron transfer is slowed down either by exciplex formation or by a low Franck-Condon factor. In radical ion pairs for which the electron transfer is efficient, the electron tunnels prior to the spin exchange, and the multiplet CIDEP is due to dipole-dipole interactions of electron spins. The corresponding polarization factor is of the order of several Boltzmann units. In appearance, such a polarization is similar to the usual exchange-induced multiplet CIDEP at J > 0. It is concluded that the long-range dipole-dipole interaction caused a 'J > 0' multiplet CIDEP in all the pairs that involved a solvated electron as a partner. RP Shkrob, IA (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 34 TC 13 Z9 13 U1 1 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 JAN 10 PY 1997 VL 264 IS 3-4 BP 417 EP 423 DI 10.1016/S0009-2614(96)01344-9 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WD049 UT WOS:A1997WD04900027 ER PT J AU Bohle, DS Dinnebier, RE Madsen, SK Stephens, PW AF Bohle, DS Dinnebier, RE Madsen, SK Stephens, PW TI Characterization of the products of the heme detoxification pathway in malarial late trophozoites by X-ray diffraction SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PLASMODIUM-FALCIPARUM; BETA-HEMATIN; FERRIPROTOPORPHYRIN-IX; POWDER DIFFRACTION; PIGMENT; CHLOROQUINE; POLYMERIZATION; HAEMOZOIN AB In a process inhibited by the quinoline antimalarial drugs, Plasmodia detoxify heme released during the degradation of hemoglobin by aggregating it into malarial pigment, an insoluble crystalline heme coordination polymer. Synchrotron x-ray powder diffraction patterns for intact desiccated malarial trophozoites and synthetic beta-hematin have been measured; both materials correspond to a single crystalline triclinic lattice with unit cell parameters a = 12.2176(4), b = 14.7184(5), c = 8.0456(3) Angstrom; alpha = 90.200(2), beta = 96.806(3), gamma = 97.818(3) degrees and Z = 2. These results unambiguously demonstrate that hemozoin crystallites are identical to synthetic beta-hematin. C1 SUNY STONY BROOK,DEPT PHYS,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RP Bohle, DS (reprint author), UNIV WYOMING,DEPT CHEM,LARAMIE,WY 82071, USA. RI Dinnebier, Robert/B-5642-2015 OI Dinnebier, Robert/0000-0003-2778-2113 NR 29 TC 119 Z9 121 U1 1 U2 8 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 10 PY 1997 VL 272 IS 2 BP 713 EP 716 PG 4 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WC048 UT WOS:A1997WC04800005 PM 8995354 ER PT J AU Asano, K Kinzy, TG Merrick, WC Hershey, JWB AF Asano, K Kinzy, TG Merrick, WC Hershey, JWB TI Conservation and diversity of eukaryotic translation initiation factor eIF3 SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID MAMMALIAN PROTEIN-SYNTHESIS; AMINO-ACID-SEQUENCE; RABBIT RETICULOCYTES; GEL-ELECTROPHORESIS; HELA-CELLS; YEAST; RNA; COMPLEX; SUBUNIT; CLONING AB The largest of the mammalian translation initiation factors, eIF3, consists of at least eight subunits ranging in mass from 35 to 170 kDa. eIF3 binds to the 40 S ribosome in an early step of translation initiation and promotes the binding of methionyl tRNA(i) and mRNA. We report the cloning and characterization of human cDNAs encoding two of its subunits, p110 and p36. It was found that the second slowest band during polyacrylamide gel electrophresis of eIF3 subunits in sodium dodecyl sulfate contains two proteins: p110 and p116. Analysis of the cloned cDNA encoding p110 indicates that its amino acid sequence is 31% identical to that of the yeast protein, Nip1. The p116 cDNA was cloned and characterized as a human homolog of yeast Prt1, as described elsewhere (Methot, N., Rom, E., Olsen, H., and Sonenberg, N. (1997) J. Biol. Chem. 272, 1110-1116). p36 is a WD40 repeat protein, which is 46% identical to the p39 subunit of yeast eIF3 and is identical to TRIP-1, a phosphorylation substrate of the TGF-beta type II receptor. The p116, p110, and p36 subunits localize on 40 S ribosomes in cells active in translation and co-immunoprecipitate with affinity-purified antibodies against the p170 subunit, showing that these proteins are integral components of eIF3. Although p36 and p116 have homologous protein subunits in yeast eIF3, the p110 homolog, Nip1, is not detected in yeast eIF3 preparations. The results indicate both conservation and diversity in eIF3 between yeast and humans. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,DEPT BIOL CHEM,DAVIS,CA 95616. CASE WESTERN RESERVE UNIV,SCH MED,DEPT BIOCHEM,CLEVELAND,OH 44106. FU NIGMS NIH HHS [GM22135, GM36467, GM26796] NR 43 TC 111 Z9 118 U1 0 U2 3 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 10 PY 1997 VL 272 IS 2 BP 1101 EP 1109 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WC048 UT WOS:A1997WC04800060 PM 8995409 ER PT J AU Dickens, GR QuinbyHunt, MS AF Dickens, GR QuinbyHunt, MS TI Methane hydrate stability in pore water: A simple theoretical approach for geophysical applications SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BOTTOM-SIMULATING-REFLECTORS; CASCADIA ACCRETIONARY PRISM; MIXED-ELECTROLYTE-SOLUTIONS; HEAT-FLOW; THERMODYNAMIC PROPERTIES; VELOCITY STRUCTURE; FLUID INCLUSIONS; SODIUM-CHLORIDE; GAS; DISSOCIATION AB Geophysicists have recently expressed an interest in understanding how pore water composition affects CH4 hydrate stability conditions in the marine environment. It has previously been shown in the chemical engineering literature that CH4 hydrate stability conditions in electrolyte solutions are related to the activity of water (a(w)). Here we present additional experimental data in support of this relationship and then use the relationship to address issues relevant to geophysicists. Pressure and temperature conditions of CH4 hydrate dissociation were determined for 10 solutions containing variable concentrations of Cl-, SO42-, Br-, Na+, K+, Mg2+, NH4+, and Cu2+. The reciprocal temperature offset of CH4 hydrate dissociation between the CH4-pure water system and each of these solutions (and for other electrolyte solutions in literature) is directly related to the logarithm of the activity of water (lna(w)). Stability conditions for CH4 hydrate in any pore water system therefore can be predicted simply and accurately by calculating lna(w). The effect of salinity variation and chemical diagenesis on CH4 hydrate stability conditions in the marine environment can be evaluated by determining how these processes affect lna(w) of pore water. C1 UNIV MICHIGAN, DEPT GEOL SCI, ANN ARBOR, MI 48109 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV ENERGY & ENVIRONM, BERKELEY, CA 94720 USA. RI Dickens, Gerald/G-1222-2011 NR 50 TC 76 Z9 93 U1 3 U2 8 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 JAN 10 PY 1997 VL 102 IS B1 BP 773 EP 783 DI 10.1029/96JB02941 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WC628 UT WOS:A1997WC62800023 ER PT J AU Foster, I Geisler, J Kesselman, C Tuecke, S AF Foster, I Geisler, J Kesselman, C Tuecke, S TI Managing multiple communication methods in high-performance networked computing systems SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID PARALLEL AB Modern networked computing environments and applications often require - or can benefit from - the use of multiple communication substrates, transport mechanisms, and protocols, chosen according to where communication is directed, what is communicated, or when communication is performed. We propose techniques that allow multiple communication methods to be supported transparently in a single application, with either automatic or user-specified selection criteria guiding the methods used for each communication. We explain how communication link and remote service request mechanisms facilitate the specification and implementation of multimethod communication. These mechanisms have been implemented in the Nexus multithreaded runtime system, and we use this system to illustrate solutions to various problems that arise when multimethod communication is implemented. We also illustrate the application of our techniques by describing a multimethod, multithreaded implementation of the Message Passing Interface (MPI) standard, constructed by integrating Nexus with the Argonne MPICH library. Finally, we present the results of experimental studies that reveal performance characteristics of multimethod communication, the Nexus-based MPI implementation, and a large scientific application running in a heterogeneous networked environment. C1 CALTECH,BECKMAN INST,PASADENA,CA 91125. RP Foster, I (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI Kesselman, Carl/0000-0003-0917-1562 NR 43 TC 33 Z9 33 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD JAN 10 PY 1997 VL 40 IS 1 BP 35 EP 48 DI 10.1006/jpdc.1996.1266 PG 14 WC Computer Science, Theory & Methods SC Computer Science GA WK399 UT WOS:A1997WK39900004 ER PT J AU Coulston, GW Bare, SR Kung, H Birkeland, K Bethke, GK Harlow, R Herron, N Lee, PL AF Coulston, GW Bare, SR Kung, H Birkeland, K Bethke, GK Harlow, R Herron, N Lee, PL TI The kinetic significance of V5+ in n-butane oxidation catalyzed by vanadium phosphates SO SCIENCE LA English DT Article ID MALEIC-ANHYDRIDE; SELECTIVE OXIDATION; PYROPHOSPHATE; STATE AB Maleic anhydride, a precursor to polyester resins, is made by oxidation oi n-butane over vanadium phosphate catalysis. This system is of general interest because it is the only heterogeneously catalyzed, alkane-selective oxidation reaction in commercial use. Time-resolved in situ x-ray absorption spectroscopy shows that when either alpha(1)-VOPO4/SiO2 or (VO)(2)P2O7/SiO2 catalysts are exposed to n-butane, the rate of maleic anhydride formation is proportional to the rate oi decay of V5+ species in the catalyst. Thus V5+ species are kinetically significant for the production of maleic anhydride and not just for the production of by-products. The results also suggest that V5+ species may play a role in the initial hydrogen abstraction from n-butane, the rate-determining step in the reaction sequence. V4+ sites appear to be responsible for by-product formation. C1 NORTHWESTERN UNIV, IPATIEFF LAB, EVANSTON, IL 60208 USA. ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP Coulston, GW (reprint author), DUPONT CO INC, WILMINGTON, DE 19880 USA. NR 21 TC 143 Z9 151 U1 6 U2 37 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 JAN 10 PY 1997 VL 275 IS 5297 BP 191 EP 193 DI 10.1126/science.275.5297.191 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WC022 UT WOS:A1997WC02200031 ER PT J AU Li, WK Ng, CY AF Li, WK Ng, CY TI Gaussian-2 ab initio study of isomeric Cl2O2 and Cl2O2+ and their dissociation reactions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID CH3O2; SPECTRA; CH3S2 AB The energetics for Cl2O2 isomers and their cations as well as the fragments of these species have been investigated at the Gaussian-2 level of ab initio theory. It is found that the calculated heats of formation and dissociation energies for Cl2O2 and Cl2O2+ isomers, as well as the ionization energies of the neutral species, are in good agreement with available experimental measurements. In addition, on the basis of these computational results, it may be concluded that both ClOOCl and ClOClO are formed in the dimerization of ClO. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. RP Li, WK (reprint author), CHINESE UNIV HONG KONG,DEPT CHEM,SHATIN,NT,HONG KONG. NR 23 TC 37 Z9 38 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 9 PY 1997 VL 101 IS 2 BP 113 EP 115 DI 10.1021/jp962253d PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL082 UT WOS:A1997WL08200003 ER PT J AU Frank, HA Desamero, RZB Chynwat, V Gebhard, R vanderHoef, I Jansen, FJ Lugtenburg, J Gosztola, D Wasielewski, MR AF Frank, HA Desamero, RZB Chynwat, V Gebhard, R vanderHoef, I Jansen, FJ Lugtenburg, J Gosztola, D Wasielewski, MR TI Spectroscopic properties of spheroidene analogs having different extents of pi-electron conjugation SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID LIGHT-HARVESTING COMPLEX; EXCITED SINGLET-STATE; TRANS-BETA-CAROTENE; ENERGY-GAP LAW; PHOTOSYNTHETIC BACTERIA; RHODOPSEUDOMONAS-ACIDOPHILA; POLYENES; BACTERIOCHLOROPHYLL; FLUORESCENCE; SPHAEROIDES AB The spectroscopic properties of spheroidene and a series of spheroidene analogs with extents of pi-electron conjugation ranging from 7 to 13 carbon-carbon double bonds were studied using steady-state absorption, fluorescence, fluorescence excitation, and time-resolved absorption spectroscopy. The spheroidene analogs studied here were 5',6-dihydro-7',8'-didehydrospheroidene, 7',8'-didehydrospheroidene, and 1',2'-dihydro-3',4',7',8'-tetradehydrospheroidene and taken together with data from 3,4,7,s-tetrahydrospheroidene, 3,4,5,6-tetrahydrospheroidene, 3,4-dihydrospheroidene already published (DeCoster, B.; Christensen, R. L.; Gebhard, R.; Lugtenburg, J.; Farhoosh, R.; Frank, H. A. Biochim. Biophys. Acta 1992, 1102, 107) provide a systematic series of molecules for understanding the molecular features that control energy transfer to bacteriochlorophyll in photosynthetic bacterial light-harvesting complexes. All of the molecules were purified by high-pressure liquid chromatographic techniques prior to the spectroscopic experiments. The absorption spectra of the molecules were observed to red-shift with increasing extent of pi-electron conjugation. The room temperature fluorescence data show a systematic crossover from dominant S-1 --> S-0 (2(1)A(g) --> 1(1)A(g)) emission to dominant S-2 --> S-0 (1(1)B(u) --> 1(1)A(g)) With increasing extent of conjugation. The S-2 fluorescence quantum yields of all the carotenoids in the series were measured here and indicate that 3,4-dihydrospheroidene with nine carbon-carbon double bonds has an S-2 quantum yield of (2.7 +/- 0.3) x 10(-4) which is the highest value in the series. The lifetimes of the S-1 states of the molecules were determined from time-resolved transient absorption spectroscopy and found to decrease as the conjugated chain length increases. The transient data are discussed in terms of the energy gap law for radiationless transitions which allows a prediction of the S-1 energies of the molecules. The implications of these results for the process of light harvesting by carotenoids in photosynthesis are discussed. C1 LEIDEN UNIV, GORLAEUS LABS, NL-2300 RA LEIDEN, NETHERLANDS. ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NORTHWESTERN UNIV, DEPT CHEM, EVANSTON, IL 60208 USA. RP Frank, HA (reprint author), UNIV CONNECTICUT, DEPT CHEM, 215 GLENBROOK RD, STORRS, CT 06269 USA. RI Gosztola, David/D-9320-2011 OI Gosztola, David/0000-0003-2674-1379 NR 44 TC 81 Z9 84 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 JAN 9 PY 1997 VL 101 IS 2 BP 149 EP 157 DI 10.1021/jp962373l PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL082 UT WOS:A1997WL08200008 ER PT J AU Mandrus, D Kele, M Hettich, RL Guiochon, G Sales, BC Boatner, LA AF Mandrus, D Kele, M Hettich, RL Guiochon, G Sales, BC Boatner, LA TI Sonochemical synthesis of C60H2 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BUCKMINSTERFULLERENE C-60; SONOLUMINESCENCE SPECTRA; HYDROGENATION; FULLERENES; HYDROFULLERENES; CAVITATION; ION AB C60H2 has been synthesized by ultrasonically irradiating solutions of C-60 in decahydronaphthalene. This synthesis can be understood as a secondary reaction arising from the production of atomic hydrogen during sonolysis of the solvent. Continued sonication results in the eventual disappearance of both C-60 and C60H2 from the solution as monitored by UV-vis spectrophotometry. This disappearance, along with the complete absence of more highly hydrogenated derivatives, suggests that the C-60 experiences a high-energy environment during ultrasonic irradiation. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP Mandrus, D (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Mandrus, David/H-3090-2014; Boatner, Lynn/I-6428-2013; Hettich, Robert/N-1458-2016 OI Boatner, Lynn/0000-0002-0235-7594; Hettich, Robert/0000-0001-7708-786X NR 34 TC 26 Z9 26 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 9 PY 1997 VL 101 IS 2 BP 123 EP 128 DI 10.1021/jp962056e PG 6 WC Chemistry, Physical SC Chemistry GA WL103 UT WOS:A1997WL10300002 ER PT J AU Sun, H Frei, H AF Sun, H Frei, H TI Time-resolved step-scan Fourier transform infrared spectroscopy of triplet excited duroquinone in a zeolite SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID FTIR DIFFERENCE SPECTROSCOPY; LASER FLASH-PHOTOLYSIS; IR SPECTROSCOPY; RHODOBACTER-SPHAEROIDES; VIBRATIONAL-RELAXATION; BINDING-SITES; PHOTOCHEMISTRY; LIGHT; 4-PHENYLBENZOPHENONE; SPECTROMETER AB The infrared spectrum of triplet excited duroquinone occluded in zeolite NaY has been recorded by time-resolved Fourier transform-infrared spectroscopy on the nano- and microsecond time scale. A commercial step-scan instrument whose capability was expanded to allow absorption spectroscopy at nanosecond resolution was employed for this study. O-18 isotope labeling allowed assignment of a strong absorption at 1542 cm(-1) to the CO stretching mode. The 100 cm(-1) red shift of this band relative to the CO stretch of the ground state establishes the pi pi* character of the lowest triplet state of duroquinone. This is consistent with the highly polar environment of the zeolite NaY cage. The lifetime of the excited triplet state is 20 mu s (-50 degrees C). This constitutes the first time-resolved infrared spectrum of a transient molecule in a zeolite. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, CHEM BIODYNAM LAB, BERKELEY, CA 94720 USA. NR 48 TC 46 Z9 46 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 9 PY 1997 VL 101 IS 2 BP 205 EP 209 DI 10.1021/jp962136i PG 5 WC Chemistry, Physical SC Chemistry GA WL103 UT WOS:A1997WL10300013 ER PT J AU Henderson, MA AF Henderson, MA TI Complexity in the decomposition of formic acid on the TiO2(110) surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CATALYTIC DECOMPOSITION; OXIDE SURFACES; REACTION PATHS; TIO2 SURFACES; SPECTROSCOPY; ADSORPTION; SWITCHOVER; DESORPTION; CHEMISTRY; OXYGEN AB The decomposition of formic acid on the TiO2(110) surface was examined with temperature-programmed desorption (TPD), static secondary ion mass spectrometry (SSIMS), and high-resolution electron energy loss spectroscopy (HREELS). Formic acid decomposed upon adsorption on TiO2(110) at 110 K to formate and a proton. The formate species was identified in HREELS by the symmetric O-C-O stretching mode at 1365 cm(-1) and the C-H stretching mode at 2920 cm(-1). The deposited acid proton was difficult to detect in HREELS but presumably formed a hydroxyl group at a bridging two-coordinate O2- site. TPD indicated that the major formic acid decomposition products were CO and H2O, suggestive of a dehydration process. However, a dehydration mechanism is unsuitable for describing the decomposition of formic acid on TiO2(110) because the CO and H2O products were formed from independent sources and by independent surface processes. CO desorbed during decomposition of formate between 400 and 700 K, but the majority of the desorbing H2O resulted from condensation of bridging hydroxyl groups below 500 K with virtually no water desorbed during formate decomposition. Condensation of bridging hydroxyl groups left a disordered surface consisting of oxygen vacancies and adsorbed formate species. The decomposition of formate was not a straightforward process. Although CO was the major formate decomposition product, formaldehyde desorbed at 548 K as the major hydrogen-containing product, with formic acid (from formate disproportionation), water, and acetylene as additional hydrogen-containing products. Carbon dioxide desorption was also detected and coincided with formaldehyde desorption. The production of formaldehyde probably involved the oxygen vacancies produced below 500 K during water desorption. TPD results from (HCOOH)-O-16-O-16 decomposition on the O-18-enriched TiO2(110) surface indicated that oxygen exchange between the surface and the formic acid adlayer resulted in significant amounts O-18-containing TPD products (carbon monoxide, water, and formaldehyde). Analysis of the desorption rates for the two carbon monoxide species revealed that (CO)-O-18 production occurred with a higher activation barrier (75 kJ/mol) than did (CO)-O-16 (52 kJ/mol). SSIMS results indicated that oxygen exchange occurred between the surface and some adsorbed formate species at temperatures as low as 400 K. These findings reveal that the decomposition of formic acid on TiO2(110) is complex and cannot adequately be described by a simple dehydration mechanism. RP Henderson, MA (reprint author), PACIFIC NW NATL LAB, MAT & INTERFACES GRP, POB 999, MS K2-12, RICHLAND, WA 99352 USA. NR 28 TC 121 Z9 121 U1 8 U2 53 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 9 PY 1997 VL 101 IS 2 BP 221 EP 229 DI 10.1021/jp961494i PG 9 WC Chemistry, Physical SC Chemistry GA WL103 UT WOS:A1997WL10300016 ER PT J AU Einasto, J Einasto, M Gottlober, S Muller, V Saar, V Starobinsky, AA Tago, E Tucker, D Andernach, H Frisch, P AF Einasto, J Einasto, M Gottlober, S Muller, V Saar, V Starobinsky, AA Tago, E Tucker, D Andernach, H Frisch, P TI A 120-Mpc periodicity in the three-dimensional distribution of galaxy superclusters SO NATURE LA English DT Article ID RICH CLUSTERS; POWER-SPECTRUM; UNIVERSE; SCALE AB ACCORDING to the favoured models for the formation of large-scale structure in the Universe (in which the dynamics of the Universe is dominated by cold dark matter), the distribution of galaxies and clusters of galaxies should be random on large scales, It therefore came as a surprise when a periodicity was reported(1) in the distribution of high-density regions of galaxies in the directions of the Galactic poles, although the apparent lack of periodicity in other directions led to the initial report being regarded as a statistical anomaly(2). A subsequent study(3-6) also claimed evidence for periodicity on the same stale, but the statistical significance of this result was uncertain due to the small number of clusters used, Here, using a new compilation(7) of available data on galaxy clusters, we present evidence for a quasiregular three-dimensional network of rich superclusters and voids, with the regions of high density separated by similar to 120 Mpc, If this reflects the distribution of all matter (luminous and dark), then there must exist some hitherto unknown process that produces regular structure on large scales. C1 INST ASTROPHYS,D-14482 POTSDAM,GERMANY. LD LANDAU THEORET PHYS INST,MOSCOW 117946,RUSSIA. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. INST NACL INVEST AGR,ESA,JUE OBSERV,E-28080 MADRID,SPAIN. UNIV GUANAJUATO,DEPT ASTRON,GUANAJUATO,MEXICO. UNIV OBSERV,D-37083 GOTTINGEN,GERMANY. RP Einasto, J (reprint author), TARTU ASTROPHYS OBSERV,EE-2444 TORAVERE,ESTONIA. OI Starobinsky, Alexei/0000-0002-8946-9088 NR 18 TC 144 Z9 144 U1 1 U2 7 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 9 PY 1997 VL 385 IS 6612 BP 139 EP 141 DI 10.1038/385139a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WB728 UT WOS:A1997WB72800047 ER PT J AU Lu, HP Xie, XS AF Lu, HP Xie, XS TI Single-molecule spectral fluctuations at room temperature SO NATURE LA English DT Article ID PENTACENE MOLECULES; OPTICAL MICROSCOPY; IMPURITY MOLECULES; TERPHENYL CRYSTAL; FLUORESCENCE; SPECTROSCOPY; DIFFUSION; DYNAMICS AB RECENT advances in near-field(1) and far-field(2,3) fluorescence microscopy have made it possible to image single molecules and measure their emission(3,4) and excitation(5) spectra and fluorescence lifetimes(3,6-8) at room temperature. These studies have revealed spectral shifts(4) and intensity fluctuations(6,7), the origins of which are not clear. Here we show that spontaneous fluctuations in the spectra of immobilized single dye molecules occur on two different timescales: hundreds of milliseconds and lens of seconds, indicating that these fluctuations have two distinct activation energies, In addition, we see photoinduced spectral fluctuations on repealed photoexcitation of single molecules. We suggest that ail of these fluctuations can be understood as transitions between metastable minima in the molecular potential-energy surface. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 18 TC 292 Z9 294 U1 4 U2 39 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 9 PY 1997 VL 385 IS 6612 BP 143 EP 146 DI 10.1038/385143a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WB728 UT WOS:A1997WB72800049 ER PT J AU Abele, A Adomeit, J Amsler, C Armstrong, DS Baker, CA Barnett, BM Beuchert, K Birien, P Bischoff, S Blum, P Batty, CJ Benayoun, M Berdoz, A Braune, K Brose, J Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Degener, T Dietz, HP Djaoshvili, N Dombrowski, SV Doser, M Dunnweber, W Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Herz, M Hessey, NP Hidas, P Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kiel, T Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Noble, A Ouared, R OuldSaada, F Peters, K Pinder, CN Pinter, G Regenfus, C Reissmann, J Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Urner, D Volcker, C Walter, F Walther, D Wiedner, U Zou, BS AF Abele, A Adomeit, J Amsler, C Armstrong, DS Baker, CA Barnett, BM Beuchert, K Birien, P Bischoff, S Blum, P Batty, CJ Benayoun, M Berdoz, A Braune, K Brose, J Bugg, DV Case, T Cooper, A Cramer, O Crowe, KM Degener, T Dietz, HP Djaoshvili, N Dombrowski, SV Doser, M Dunnweber, W Engelhardt, D Faessler, MA Giarritta, P Hackmann, R Haddock, RP Heinsius, FH Herz, M Hessey, NP Hidas, P Holtzhaussen, C Jamnik, D Kalinowsky, H Kalteyer, B Kammle, B Kammel, P Kiel, T Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Lakata, M Landua, R Ludemann, J Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Noble, A Ouared, R OuldSaada, F Peters, K Pinder, CN Pinter, G Regenfus, C Reissmann, J Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Urner, D Volcker, C Walter, F Walther, D Wiedner, U Zou, BS TI High-mass rho-meson states from (p)over-bar-d-annihilation at rest into pi-pi 0 pi 0P(spectator) SO PHYSICS LETTERS B LA English DT Article ID ANNIHILATION; DECAY AB A study of (p) over bar-annihilation in liquid deuterium into pi(-)pi(0) pi(0) and a spectator-proton is presented. A cut on the proton-momentum of less than or equal to 100 MeV/c ensures that annihilation takes place on a quasi-free neutron. A partial wave analysis shows contributions from three vector mesons, with masses and widths of (763.7 +/- 3.2; 152.8 +/- 4.3), (1411 +/- 14; 343 +/- 20); (1780(-29)(+37); 275 +/- 45) meV/c(2), respectively. C1 RUHR UNIV BOCHUM,D-44780 BOCHUM,GERMANY. UNIV BONN,D-53115 BONN,GERMANY. HUNGARIAN ACAD SCI,H-1525 BUDAPEST,HUNGARY. RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. CERN,CH-1211 GENEVA 4,SWITZERLAND. UNIV HAMBURG,D-22761 HAMBURG,GERMANY. UNIV KARLSRUHE,D-76021 KARLSRUHE,GERMANY. UNIV LONDON QUEEN MARY & WESTFIELD COLL,LONDON E1 4NS,ENGLAND. UNIV CALIF LOS ANGELES,LOS ANGELES,CA 90024. UNIV MAINZ,D-55099 MAINZ,GERMANY. UNIV MUNICH,D-80333 MUNICH,GERMANY. CARNEGIE MELLON UNIV,PITTSBURGH,PA 15213. CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. UNIV ZURICH,CH-8057 ZURICH,SWITZERLAND. UNIV PARIS 06,LPNHE,F-75252 PARIS,FRANCE. RP Abele, A (reprint author), UNIV CALIF BERKELEY,LBNL,BERKELEY,CA 94720, USA. RI Meyer, Curtis/L-3488-2014 OI Meyer, Curtis/0000-0001-7599-3973 NR 21 TC 38 Z9 38 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 JAN 9 PY 1997 VL 391 IS 1-2 BP 191 EP 196 DI 10.1016/S0370-2693(96)01552-3 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD167 UT WOS:A1997WD16700030 ER PT J AU Frabetti, PL Cheung, HWK Cumalat, JP Dallapiccola, C Ginkel, JF Johns, WE Nehring, MS Butler, JN Cihangir, S Gaines, I Garbincius, PH Garren, L Gourlay, SA Harding, DJ Kasper, P Kreymer, A Lebrun, P Shukla, S Vittone, M Bianco, S Fabbri, FL Sarwar, S Zallo, A Culbertson, R Gardner, RW Greene, R Wiss, J Alimonti, G Bellini, G Boschini, M Brambilla, D Caccianiga, B Cinquini, L DiCorato, M Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Meroni, E Moroni, L Pedrini, D Perasso, L Prelz, F Sala, A Sala, S Torretta, D Buchholz, D Claes, D Gobbi, B OReilly, B Bishop, JM Cason, NM Kennedy, CJ Kim, GN Lin, TF Puseljic, DL Ruchti, RC Shephard, WD Swiatek, JA Wu, ZY Arena, V Boca, G Castoldi, C Gianini, G Ratti, SP Riccardi, C Viola, L Vitulo, P Lopez, A Grim, GP Paolone, VS Yager, PM Wilson, JR Sheldon, PD Davenport, F Danyo, K Handler, T Cheon, BG Kang, JS Kim, KY AF Frabetti, PL Cheung, HWK Cumalat, JP Dallapiccola, C Ginkel, JF Johns, WE Nehring, MS Butler, JN Cihangir, S Gaines, I Garbincius, PH Garren, L Gourlay, SA Harding, DJ Kasper, P Kreymer, A Lebrun, P Shukla, S Vittone, M Bianco, S Fabbri, FL Sarwar, S Zallo, A Culbertson, R Gardner, RW Greene, R Wiss, J Alimonti, G Bellini, G Boschini, M Brambilla, D Caccianiga, B Cinquini, L DiCorato, M Giammarchi, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Meroni, E Moroni, L Pedrini, D Perasso, L Prelz, F Sala, A Sala, S Torretta, D Buchholz, D Claes, D Gobbi, B OReilly, B Bishop, JM Cason, NM Kennedy, CJ Kim, GN Lin, TF Puseljic, DL Ruchti, RC Shephard, WD Swiatek, JA Wu, ZY Arena, V Boca, G Castoldi, C Gianini, G Ratti, SP Riccardi, C Viola, L Vitulo, P Lopez, A Grim, GP Paolone, VS Yager, PM Wilson, JR Sheldon, PD Davenport, F Danyo, K Handler, T Cheon, BG Kang, JS Kim, KY TI Observation of the vector meson Cabibbo suppressed decay D+->rho(0)mu(+)nu SO PHYSICS LETTERS B LA English DT Article ID BRANCHING FRACTIONS AB We report on the first statistically significant observation of the vector meson Cabibbo, suppressed semileptonic decay D+ --> rho(0) mu(+)nu. We measure the branching ratio of the decay mode D+ --> rho(0) mu(+)nu (plus possible unobserved gamma from D+ --> eta'mu(+)nu, eta' --> gamma rho(0)) with respect to the decay mode D+ --> (K) over bar*(0) mu(+)nu to be BR (D+ --> rho(0) mu(+)nu)/BR (D+ --> (K) over bar*(0) mu(+)nu) = 0.079 +/- 0.019 (stat) +/- 0.013 (syst). Data were collected by Fermilab photoproduction experiment E687. C1 IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. UNIV COLORADO,BOULDER,CO 80309. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,LAB NAZL FRASCATI,I-00044 FRASCATI,ITALY. UNIV ILLINOIS,URBANA,IL 61801. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV PAVIA,DIPARTIMENTO FIS NUCL & TEOR,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PUERTO RICO,MAYAGUEZ,PR. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV S CAROLINA,COLUMBIA,SC 29208. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV N CAROLINA,ASHEVILLE,NC 28804. UNIV TENNESSEE,KNOXVILLE,TN 37996. KOREA UNIV,SEOUL 136701,SOUTH KOREA. RP Frabetti, PL (reprint author), UNIV BOLOGNA,DIP FIS,I-40126 BOLOGNA,ITALY. NR 11 TC 9 Z9 9 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 9 PY 1997 VL 391 IS 1-2 BP 235 EP 242 DI 10.1016/S0370-2693(96)01548-1 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD167 UT WOS:A1997WD16700034 ER PT J AU Reinot, T Hayes, JM Small, GJ AF Reinot, T Hayes, JM Small, GJ TI Electronic dephasing and electron-phonon coupling of aluminum phthalocyanine tetrasulphonate in hyperquenched and annealed glassy films of ethanol and methanol over a broad temperature range SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PICOSECOND PHOTON-ECHO; OPTICAL HOMOGENEOUS LINEWIDTHS; HOLE BURNING EXPERIMENTS; POLYATOMIC-MOLECULES; ORGANIC GLASSES; APPARENT CONTRADICTION; SPECTRAL DIFFUSION; POLYVINYL-ALCOHOL; CONDENSED PHASES; SOLVENT DYNAMICS AB The electronic dephasing (spectral dynamics) and electron-phonon coupling of aluminum phthalocyanine tetrasulphonate (APT) in glassy films of ethanol and methanol were investigated by nonphotochemical hole burning over a broad temperature range, similar to 5-100 K. Films formed by hyperquenching (similar to 10(6) K s(-1)) at 4.7 K were studied as well as films that were subsequently annealed at temperatures up to similar to 170 K. Results are compared against those for APT in glassy water [Kim et al., J. Phys. Chem. 99, 7300 (1995); Reinot et al., J. Chem. Phys. 104, 793 (1996)]. As in the case of water, the linear coupling is weak with a Huang-Rhys factor S similar to 0.4 but:the mean phonon frequencies for ethanol and methanol of 26 and 17 cm(-1) are considerably lower than the 38 cm(-1) value for water. These modes are assigned as pseudolocalized with significant amplitude (libration) localized an APT. Below about 8 K, the electronic dephasing/spectral diffusion is dominated by coupling to the tunneling intrinsic two-level systems of the glass. At higher temperatures the electronic dephasing is dominated by the exchange coupling mechanism, which derives from diagonal quadratic electron-phonon coupling. Here, for both ethanol and water, a pseudolocalized model(s) at similar to 50 cm(-1) is operative. This frequency corresponds to a peak in the spectral density of the liquids which for water is due to the transverse acoustic mode. The results show that the modes responsible for linear and quadratic coupling are distinctly different. Implications of this for optical coherence loss in liquids are considered. Novel results from annealing experiments are reported and discussed in terms of the complex phase diagrams of ethanol and methanol. Formation of the glass from the supercooled liquid just above the melting point of a crystalline phase leads to a marked reduction (similar to 10X) in the homogeneous width of the zero-phonon hole at 4.7 K. This is interpreted in terms of a reduction in the density of intrinsic two-level systems due to reduced structural disorder of the glass formed from the supercooled liquid. As in the case of water, the highly efficient hole burning in glassy ethanol and methanol is observed to become highly inefficient upon formation of a crystalline phase as predicted by the Shu-Small mechanism for nonphotochemical hole burning. The close connection between this mechanism and Onsager's inverse snowball effect for solvent dynamics around an instantaneously created point charge or dipole in a liquid is emphasized. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. RP Reinot, T (reprint author), IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011, USA. NR 55 TC 40 Z9 41 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 1997 VL 106 IS 2 BP 457 EP 466 DI 10.1063/1.473387 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WB843 UT WOS:A1997WB84300002 ER PT J AU Li, X Huang, YL Flesch, GD Ng, CY AF Li, X Huang, YL Flesch, GD Ng, CY TI Absolute state-selected total cross sections for the ion-molecule reactions O+(S-4,D-2,P-2)+H-2(D-2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POTENTIAL-ENERGY SURFACE; CHARGE-TRANSFER REACTIONS; ISOTOPIC VARIANTS D2; RELATIVE ENERGIES; EXCITED-STATES; TEMPERATURE-DEPENDENCE; RATE COEFFICIENT; GASEOUS IONS; H2O+ ION; COLLISIONS AB Absolute total cross sections for the state-selected reactions of O+(S-4,D-2,P-2) + H-2 (D-2) have been measured in the center-of-mass collision energy (E(c.m.)) range of 0.02-12 eV. The cross sections for OH+ (OD+) from O+(D-2)+H-2(D-2) are slightly higher than those from O+(S-4)+H-2(D-2), whereas the OH+ (OD+) cross sections from O+ (P-2)+H-2(D-2) are approximate to 40% lower than those from O+(S-4)+H-2 (D-2) and O+ (D-2) + H-2 (D-2). At E(c.m.) <0.5 eV, the total cross sections for OH+ (OD+) from O+ (S-4)+H-2 (D-2) and O+(D-2)+H-2 (D-2) are in accord with those predicted by the Langevin-Gioumousis-Stevenson model. Significantly higher cross sections are observed for H+ (D+) and H-2(+) (D-2(+)) from O+(D-2)+H-2 (D-2) and O+(P-2)+H-2 (D-2), as compared to those from O+(S-4)+H-2 (D-2). The exothermic nature of the O+(D-2, P-2) + H-2 (D-2) charge transfer collisions accounts for the high cross sections are identified with the H+ (D+)+O+H channel, the H+ (D+) ions from the reactions involving O+(D-2) and O+(P-2) are associated mostly with the H+ (D+)+OH(OD) channel, the formation of which obeys the spin-conservation rule. The comparison of the sum (sigma(T)) of cross sections for OH+ (OD+), H-2(+) (D-2(+)), and H+ (D+) from O+(S-4)+H-2(D-2) to those from O+(D-2)+H-2(D-2) and O+(P-2)+H-2 (D-2) shows that the sigma(T)s for O+(S-4)+H-2(D-2), O+(D-2)+H-2(D-2), and O+(P-2)+H-2(D-2) at E(c.m.) <0.5 eV are comparable. At E(c.m.)>0.5 eV, the sigma(T)s for O+(P-2)+H-2 (D-2) are greater than those for O+(D-2)+H-2 (D-2), which in turn are greater than those for O+(S-4)+H-2 (D-2). This observation is attributed to the increase in the number of accessible product channels for reactions involving the excited O+(D-2) and O+(P-2) reactant ions. (C) 1997 American Institute of Physics. C1 US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT CHEM, AMES, IA 50011 USA. NR 62 TC 19 Z9 19 U1 1 U2 4 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 JAN 8 PY 1997 VL 106 IS 2 BP 564 EP 571 DI 10.1063/1.473395 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WB843 UT WOS:A1997WB84300013 ER PT J AU Wang, B Wasielewski, MR AF Wang, B Wasielewski, MR TI Design and synthesis of metal ion-recognition-induced conjugated polymers: An approach to metal ion sensory materials SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID MOLECULAR RECOGNITION; CONDUCTING POLYMERS; CROWN-ETHER; POLYTHIOPHENE; POLYPYRROLE; SENSITIVITY; IONOPHORES; RECEPTORS; COMPLEXES; BINDING AB The synthesis and metal ion responsive properties of two 2,2'-bipyridyl-phenylene-vinylene-based polymers is reported. These polymers are designed to be partially conjugated in their metal-free state and fully conjugated when exposed to metal ions so that the ion-induced conjugation enhancement can be transduced into a measurable signal. It is found that these polymers exhibit highly ionochromic effects with a wide variety of transition and main group metal ions excluding metal ions of the alkali and alkaline earth groups. For instance, both absorption and fluorescence emission bands of the polymers upon exposure to metal ions can be red-shifted up to 120 nm, depending on the metal ions present and the polymers used. C1 ARGONNE NATL LAB, DIV CHEM, ARGONNE, IL 60439 USA. NORTHWESTERN UNIV, DEPT CHEM, EVANSTON, IL 60208 USA. NR 35 TC 402 Z9 409 U1 4 U2 48 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 8 PY 1997 VL 119 IS 1 BP 12 EP 21 DI 10.1021/ja962229d PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA WB915 UT WOS:A1997WB91500003 ER PT J AU Hillier, W Lukins, P Seibert, M Wydrzynski, T AF Hillier, W Lukins, P Seibert, M Wydrzynski, T TI Photochemical reactions of photosystem II in ethylene glycol SO BIOCHEMISTRY LA English DT Article ID PHOTOSYNTHETIC OXYGEN-EVOLUTION; NANOSECOND REDUCTION KINETICS; MANGANESE-STABILIZING PROTEIN; SPINACH THYLAKOID MEMBRANES; CHLOROPHYLL-AII P-680; AMINO-ACID-RESIDUES; S-STATE TRANSITIONS; O-2 EVOLUTION; D1 POLYPEPTIDE; ENZYMATIC CATALYSIS AB The behavior of photosystem II (PSII) reactions was investigated under conditions of decreasing water content by the addition of increasing concentrations of ethylene glycol (EG). The photosynthetic activities were measured for PSII samples either directly in aqueous solutions of EG or in the standard buffer medium following EG treatment, Several effects on PSII arise upon exposure to EC. Below 50% EG there are no significant Irreversible changes, although there is a slowing of the Q(A)(-) reoxidation kinetics in the presence of EG. At concentrations of 50-70% EG, protein structural changes occur that include the release of the 16, 23, and 33 kDa extrinsic proteins and two of the catalytic Mn ions. For these samples, the capacity for O-2 evolution is considerably reduced and the formation of donor side H2O2 is enhanced. In 60% EC, the nanosecond components in the rate of P680(+) reduction are converted entirely to microsecond kinetics which upon return of the sample to the standard buffer medium are partially restored, indicating that EG has a reversible, solvent effect on the PSII donor side. At concentrations of EG >70% chlorophyll fluorescence measurements reveal reversible increases in the F-0 level concomitant with the generation and disappearance of a 5 mu s decay component in the P680(+) reduction kinetics. This result may indicate a solvent-induced uncoupling of the light harvesting pigment bed from the reaction center complex. As the EG concentration is increased to 80-100%, there is an irreversible loss of the primary charge separation. The use of EC as a cryoprotectant and as a water-miscible organic solvent for PSII is discussed. C1 UNIV SYDNEY,SCH PHYS,SYDNEY,NSW 2006,AUSTRALIA. NATL RENEWABLE ENERGY LAB,BASIC SCI CTR,GOLDEN,CO 80401. RP Hillier, W (reprint author), AUSTRALIAN NATL UNIV,RES SCH BIOL SCI,CANBERRA,ACT 0200,AUSTRALIA. RI Wydrzynski, Thomas/C-9630-2009 NR 87 TC 7 Z9 7 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 7 PY 1997 VL 36 IS 1 BP 76 EP 85 DI 10.1021/bi961724j PG 10 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WB623 UT WOS:A1997WB62300012 PM 8993320 ER PT J AU Ward, JL Jackson, GJ Beale, MH Gaskin, P Hedden, P Mander, LN Phillips, AL Seto, H Talon, M Willis, CL Wilson, TM Zeevaart, JAD AF Ward, JL Jackson, GJ Beale, MH Gaskin, P Hedden, P Mander, LN Phillips, AL Seto, H Talon, M Willis, CL Wilson, TM Zeevaart, JAD TI Stereochemistry of the oxidation of gibberellin 20-alcohols, GA(15) and GA(44), to 20-aldehydes by gibberellin 20-oxidases SO CHEMICAL COMMUNICATIONS LA English DT Article ID EXPRESSION; BIOSYNTHESIS; ARABIDOPSIS; CLONING AB (20R)- and (20S)- [20-H-2(1)]-gidberellins A(15) and A(44) have been used to determine the stereochemistry bf the conversion to the 20-aldehyde catalysed by gibberellin 20-oxidases. C1 UNIV BRISTOL,LONG ASHTON RES STN,DEPT AGR SCI,IACR,BRISTOL BS18 9AF,AVON,ENGLAND. AUSTRALIAN NATL UNIV,RES SCH CHEM,CANBERRA,ACT 0200,AUSTRALIA. MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. UNIV BRISTOL,SCH CHEM,BRISTOL BS8 1TS,AVON,ENGLAND. RI Talon, Manuel/C-8540-2014 OI Talon, Manuel/0000-0003-4291-9333 NR 10 TC 17 Z9 17 U1 1 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD JAN 7 PY 1997 IS 1 BP 13 EP 14 DI 10.1039/a606158c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WE045 UT WOS:A1997WE04500005 ER PT J AU Kuksenkov, DV Temkin, H Lear, KL Hou, HQ AF Kuksenkov, DV Temkin, H Lear, KL Hou, HQ TI Spontaneous emission factor in oxide confined vertical-cavity lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACE-EMITTING LASERS; MICROCAVITY LASERS AB We report on measurements of the spontaneous emission factor for oxide-confined InGaAs vertical cavity surface emitting lasers. The spontaneous emission factor is determined as a function of the active layer volume from the measurement of small-signal harmonic distortion at threshold. For a 3x3 mu m oxide aperture device we obtain spontaneous emission factor of 4.2 . 10(-2) at room temperature. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Kuksenkov, DV (reprint author), TEXAS TECH UNIV,DEPT ELECT ENGN,LUBBOCK,TX 79409, USA. NR 17 TC 9 Z9 9 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 6 PY 1997 VL 70 IS 1 BP 13 EP 15 DI 10.1063/1.119288 PG 3 WC Physics, Applied SC Physics GA WA662 UT WOS:A1997WA66200005 ER PT J AU Schmidt, R AF Schmidt, R TI Clarification SO CHEMICAL & ENGINEERING NEWS LA English DT Letter RP Schmidt, R (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0009-2347 J9 CHEM ENG NEWS JI Chem. Eng. News PD JAN 6 PY 1997 VL 75 IS 1 BP 75 EP 75 PG 1 WC Chemistry, Multidisciplinary; Engineering, Chemical SC Chemistry; Engineering GA WA952 UT WOS:A1997WA95200025 ER PT J AU Burke, DG Kurcewicz, W Lovhoiden, G Borge, MJG Cronqvist, M Gabelmann, H Gietz, H Hill, P Kaffrell, N Mattsson, S Naumann, RA Nybo, K Nyman, G Rogowski, J Struble, GL Thorsteinsen, TF AF Burke, DG Kurcewicz, W Lovhoiden, G Borge, MJG Cronqvist, M Gabelmann, H Gietz, H Hill, P Kaffrell, N Mattsson, S Naumann, RA Nybo, K Nyman, G Rogowski, J Struble, GL Thorsteinsen, TF TI Search for stable octupole deformation in Fr-225 SO NUCLEAR PHYSICS A LA English DT Article DE Rn-225(beta) [from Th-232(p,5p3n), mass separation]; measured E(gamma), I-gamma, E(epsilon), I(ce), T-1/2; gamma gamma-coincidences, e gamma-coincidences; Ra-226(t,alpha), E=18 MeV; measured sigma(E(alpha)); Fr-225 deduced levels, (t,alpha) Q-value; ICC, multipolarities, I-pi, rotational bands, E1 transition strengths; Ge and Si(Li) detectors; mini-orange spectrometer; magnetic spectrograph ID NUCLEAR-STRUCTURE; REFLECTION ASYMMETRY; HYPERFINE STRUCTURES; ISOTOPE SHIFTS; ODD; RA-225; PA-229; MULTIPOLARITIES; SEPARATION; SYMMETRY AB Levels in Fr-225 have been studied by gamma-ray and conversion-electron spectroscopy following the beta-decay of Rn-225 and by the Ra-226(t,alpha)Fr-225 single-proton-pickup reaction. Multipolarities were obtained for similar to 50 gamma-transitions, and a level scheme was established in which definite spin-parity values were determined for over 20 of the 48 levels. Although low-lying rotational bands of both parities exist for K = 1/2 and K = 3/2, there is no experimental evidence to claim these are parity doublets. E1 strengths connecting the K-pi = 3/2(+/-) bands are intermediate between those for nuclides which are reflection symmetric and those claimed to be octupole deformed. The (t,alpha) cross sections are in better agreement with those predicted for the reflection-symmetric case than with those from an octupole-deformed description. These observations may be confirming theoretical predictions that octupole correlations are important in Fr-225, but that there is no large stable octupole deformation. C1 UNIV WARSAW,INST EXPT PHYS,PL-00681 WARSAW,POLAND. CERN,DIV PPE,CH-1211 GENEVA 23,SWITZERLAND. UNIV BERGEN,DEPT PHYS,N-5007 BERGEN,NORWAY. UNIV OSLO,DEPT PHYS,N-0316 OSLO,NORWAY. CSIC,INST STRUCT MATTER,E-28006 MADRID,SPAIN. CHALMERS UNIV TECHNOL,DEPT PHYS,S-41296 GOTHENBURG,SWEDEN. UNIV MAINZ,INST KERNCHEM,D-6500 MAINZ,GERMANY. DARTMOUTH COLL,HANOVER,NH 03755. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Burke, DG (reprint author), MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. NR 42 TC 7 Z9 7 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 6 PY 1997 VL 612 IS 1 BP 91 EP 142 DI 10.1016/S0375-9474(96)00311-9 PG 52 WC Physics, Nuclear SC Physics GA WC515 UT WOS:A1997WC51500005 ER PT J AU Veil, JA AF Veil, JA TI Npdes permits have increased emphasis on control of toxic pollutants SO OIL & GAS JOURNAL LA English DT Article RP Veil, JA (reprint author), ARGONNE NATL LAB,WATER POLICY PROGRAM,WASHINGTON,DC, USA. NR 1 TC 3 Z9 3 U1 1 U2 2 PU PENNWELL PUBL CO ENERGY GROUP PI TULSA PA 1421 S SHERIDAN RD PO BOX 1260, TULSA, OK 74101 SN 0030-1388 J9 OIL GAS J JI Oil Gas J. PD JAN 6 PY 1997 VL 95 IS 1 BP 46 EP & PG 5 WC Energy & Fuels; Engineering, Petroleum SC Energy & Fuels; Engineering GA WB757 UT WOS:A1997WB75700014 ER PT J AU Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, TL Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, S Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J AF Abe, K Abe, K Abt, I Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, TL Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hallewell, GD Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, S Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J TI First measurement of the left-right charge asymmetry in hadronic Z boson decays and a new determination of sin(2)O(w)(eff) SO PHYSICAL REVIEW LETTERS LA English DT Article ID CROSS-SECTION ASYMMETRY; E+E COLLISIONS AB We present the first measurement of the left-right charge asymmetry A(Q)(obs) in hadronic Z boson decays. This was performed at E(c.m.) = 91.27 GeV with the SLD at the SLAG Linear Collider with a polarized electron beam. Using 89 838 events we obtain A(Q)(obs) = 0.225 +/- 0.056 +/- 0.019, which leads to a measurement of the electron left-right asymmetry parameter. A(e) = 0.162 +/- 0.041 +/- 0.014, and sin(2) theta(W)(eff) = 0.2297 +/- 0.0052 +/- 0.0018, Also, the Ag measurement combined with the left-right cross section asymmetry determines A(e) independent of the value of the electron-beam polarization. C1 ADELPHI UNIV, GARDEN CITY, NY 11530 USA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. BRUNEL UNIV, UXBRIDGE UB8 3PH, MIDDX, ENGLAND. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. UNIV COLORADO, BOULDER, CO 80309 USA. COLUMBIA UNIV, NEW YORK, NY USA. UNIV FERRARA, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV ILLINOIS, URBANA, IL 61801 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV MASSACHUSETTS, AMHERST, MA 01003 USA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW 119899, RUSSIA. UNIV OREGON, EUGENE, OR 97403 USA. IST NAZL FIS NUCL, I-35100 PADUA, ITALY. UNIV PADUA, I-35100 PADUA, ITALY. IST NAZL FIS NUCL, I-56100 PISA, ITALY. UNIV PISA, I-56100 PISA, ITALY. RUTGERS STATE UNIV, PISCATAWAY, NJ 08855 USA. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. SOGANG UNIV, SEOUL, SOUTH KOREA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. TOHOKU UNIV, SENDAI, MIYAGI 980, JAPAN. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. RP Abe, K (reprint author), NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. RI de Sangro, Riccardo/J-2901-2012; Cavalli-Sforza, Matteo/H-7102-2015; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016 OI de Sangro, Riccardo/0000-0002-3808-5455; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636 NR 12 TC 16 Z9 16 U1 0 U2 0 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 JAN 6 PY 1997 VL 78 IS 1 BP 17 EP 21 DI 10.1103/PhysRevLett.78.17 PG 5 WC Physics, Multidisciplinary SC Physics GA WA709 UT WOS:A1997WA70900005 ER PT J AU Stadler, A Gross, F AF Stadler, A Gross, F TI Relativistic calculation of the triton binding energy and its implications SO PHYSICAL REVIEW LETTERS LA English DT Article ID MONTE-CARLO CALCULATIONS; OBSERVABLES; EQUATIONS; MODEL; HE-4; H-3 AB First results for the triton binding energy obtained from the relativistic spectator or Gross equation are reported. The Dirac structure of the nucleons is taken into account. Numerical results ars presented for a family of realistic one-boson exchange models with off-shell scalar couplings. It is shown that these off-shell couplings improve both the fits to the two-body data and the predictions for the binding energy. C1 THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606. UNIV LISBON,CTR FIS NUCL,P-1699 LISBON,PORTUGAL. RP Stadler, A (reprint author), COLL WILLIAM & MARY,WILLIAMSBURG,VA 23185, USA. RI Stadler, Alfred/C-5550-2009 OI Stadler, Alfred/0000-0002-9596-0770 NR 18 TC 79 Z9 79 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 JAN 6 PY 1997 VL 78 IS 1 BP 26 EP 29 DI 10.1103/PhysRevLett.78.26 PG 4 WC Physics, Multidisciplinary SC Physics GA WA709 UT WOS:A1997WA70900007 ER PT J AU Lehrman, M Rechester, AB White, RB AF Lehrman, M Rechester, AB White, RB TI Symbolic analysis of chaotic signals and turbulent fluctuations SO PHYSICAL REVIEW LETTERS LA English DT Article AB The symbolic analysis introduced in this paper allows quantitative description of of dynamical coupling between different time signals. Ln order to demonstrate how this method works we applied it to the explicit examples of chaotic signals. Our results appear to be quite robust when external noise is added. C1 PRINCETON PLASMA PHYS LAB,PRINCETON,NJ 08543. RP Lehrman, M (reprint author), INST NONLINEAR SCI APPLICAT,SHARON,MA 02067, USA. RI White, Roscoe/D-1773-2013 OI White, Roscoe/0000-0002-4239-2685 NR 12 TC 59 Z9 70 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 6 PY 1997 VL 78 IS 1 BP 54 EP 57 DI 10.1103/PhysRevLett.78.54 PG 4 WC Physics, Multidisciplinary SC Physics GA WA709 UT WOS:A1997WA70900014 ER PT J AU Mitchell, TB Schauer, MM Barnes, DC AF Mitchell, TB Schauer, MM Barnes, DC TI Observation of spherical focus in an electron penning trap SO PHYSICAL REVIEW LETTERS LA English DT Article AB We produce simultaneously dense and well-confined nonneutral plasmas by spherical focusing. A small (3 mm radius) Penning trap has low-energy electrons injected at a single pole of the sphere. Precisely when the trap parameters art adjusted to produce a spherical well, the system self-organizes into a spherical state through a bootstrapping mechanism which produces 3 hysteresis. Additional confirmation of the dense spherical focus is provided by electrons scattered by the central core. Core densities up to 35 times the Brillouin density have been inferred from the data. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. NR 7 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 JAN 6 PY 1997 VL 78 IS 1 BP 58 EP 61 DI 10.1103/PhysRevLett.78.58 PG 4 WC Physics, Multidisciplinary SC Physics GA WA709 UT WOS:A1997WA70900015 ER PT J AU Holian, BL Blumenfeld, R Gumbsch, P AF Holian, BL Blumenfeld, R Gumbsch, P TI An Einstein model of brittle crack propagation SO PHYSICAL REVIEW LETTERS LA English DT Article ID DYNAMIC FRACTURE; INSTABILITY AB We propose a minimal nonlinear model of brittle crack propagation by considering only the motion of the crack-tip atom. The model captures many essential features of steady-state crack velocity and is in excellent quantitative agreement with many-body dynamical simulations. The model exhibits lattice trapping. For loads just above this, the crack velocity rises sharply, reaching a limiting value well below that predicted by elastic continuum theory. We trace the origin of the low limiting velocity to the anharmonicity of the potential well experienced by the crack-tip atom. C1 CAMBRIDGE HYDRODYNAM,PRINCETON,NJ 08542. MAX PLANCK INST MET RES,D-70174 STUTTGART,GERMANY. RP Holian, BL (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. RI Gumbsch, Peter/E-5879-2012 OI Gumbsch, Peter/0000-0001-7995-228X NR 17 TC 25 Z9 25 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 JAN 6 PY 1997 VL 78 IS 1 BP 78 EP 81 DI 10.1103/PhysRevLett.78.78 PG 4 WC Physics, Multidisciplinary SC Physics GA WA709 UT WOS:A1997WA70900020 ER PT J AU Ramos, MA Vieira, S Bermejo, FJ Dawidowski, J Fischer, HE Schober, H Gonzalez, MA Loong, CK Price, DL AF Ramos, MA Vieira, S Bermejo, FJ Dawidowski, J Fischer, HE Schober, H Gonzalez, MA Loong, CK Price, DL TI Quantitative assessment of the effects of orientational and positional disorder on glassy dynamics SO PHYSICAL REVIEW LETTERS LA English DT Article ID LOW-TEMPERATURE PROPERTIES; MODEL GLASS; THERMAL-CONDUCTIVITY; HEAT; SOLIDS AB The microscopic dynamics of several phases of solid ethanol are studied under the same thermodynamic conditions by inelastic neutron scattering. It is found that the vibrational density of states of the orientational glass phase, where the molecules are arranged on an ordered lattice but with disordered orientations, is very similar to that of the structural glass phase, where the molecules are disordered both in position and orientation. Low-temperature specific heat measurements on the same phases strongly support the neutron measurements. We therefore find that positional disorder. even in a stoichiometrically homogeneous system such as ethanol, is not essential for the manifestation of glasslike behavior to an extent comparable with that exhibited by the structural glass. C1 CSIC,INST ESTRUCTURA MAT,E-28006 MADRID,SPAIN. INST LAUE LANGEVIN,F-38042 GRENOBLE 9,FRANCE. ARGONNE NATL LAB,ARGONNE,IL 60439. RP Ramos, MA (reprint author), UNIV AUTONOMA MADRID,FAC CIENCIAS,LAB BAJAS TEMP,DEPT FIS MAT CONDENSADA,E-28049 MADRID,SPAIN. RI Price, David Long/A-8468-2013; vieira, sebastian/L-5216-2014; Gonzalez, Miguel/R-8330-2016; Fischer, Henry/D-5299-2012; OI vieira, sebastian/0000-0002-3854-1377; Gonzalez, Miguel/0000-0002-3478-0215; Fischer, Henry/0000-0002-1204-0750; Ramos, Miguel Angel/0000-0002-2157-9774 NR 30 TC 148 Z9 148 U1 0 U2 20 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 JAN 6 PY 1997 VL 78 IS 1 BP 82 EP 85 DI 10.1103/PhysRevLett.78.82 PG 4 WC Physics, Multidisciplinary SC Physics GA WA709 UT WOS:A1997WA70900021 ER PT J AU Kim, SH Park, SH Doering, CR Ryu, CS AF Kim, SH Park, SH Doering, CR Ryu, CS TI Reentrant transitions in globally coupled active rotators with multiplicative and additive noises SO PHYSICS LETTERS A LA English DT Article DE nonequilibrium; multiplicative noise; noise-induced transition; reentrant transition; rotators; additive noise ID PHASE-TRANSITIONS; OSCILLATORS; DYNAMICS; SYNCHRONIZATION; ENTRAINMENT; LATTICES; SYSTEMS AB We study the nonequilibrium phenomena in globally coupled active rotators with multiplicative and additive noises, It is shown that at a critical value of the multiplicative noise intensity the system undergoes noise-induced transition from a one-cluster state to a two-cluster state, Additive noise suppresses the effect of the multiplicative noise on the system, increasing the critical value of the multiplicative noise intensity, The system shows a reentrant transition at intermediate additive noise intensity. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Kim, SH (reprint author), ELECT & TELECOMMUN RES INST,RES DEPT,POB 106,TAEJON 305600,SOUTH KOREA. NR 24 TC 16 Z9 16 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JAN 6 PY 1997 VL 224 IS 3 BP 147 EP 153 DI 10.1016/S0375-9601(96)00847-X PG 7 WC Physics, Multidisciplinary SC Physics GA WC510 UT WOS:A1997WC51000001 ER PT J AU Sutjianto, A Curtiss, LA AF Sutjianto, A Curtiss, LA TI Theoretical study of the potential energy surface of diglyme SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE CALCULATIONS; CONFORMATIONAL-ANALYSIS; BASIS SETS; 1,2-DIMETHOXYETHANE; SIMULATIONS AB The potential energy surface of diglyme has been investigated using ab initio molecular orbital theory. The all-trans conformer and 20 conformers having either one- or two-gauche conformations around C-C or C-O bonds were studied at the HF/6-31G(d) level, The four lowest energy structures were further investigated with larger basis sets and with inclusion of correlation effects. At the highest level of theory, the tg(+)g(-)t(3) conformer is 0.1 kcal/mol more stable than the all-trans conformer, while the tgt(4) and g(+)g(-)t(4) conformers are slightly less stable than the all-trans conformer. RP Sutjianto, A (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 17 TC 10 Z9 10 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 JAN 3 PY 1997 VL 264 IS 1-2 BP 127 EP 133 DI 10.1016/S0009-2614(96)01315-2 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WC716 UT WOS:A1997WC71600019 ER PT J AU Gregori, L Hainfeld, JF Simon, MN Goldgaber, D AF Gregori, L Hainfeld, JF Simon, MN Goldgaber, D TI Binding of amyloid beta protein to the 20 S proteasome SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PAIRED HELICAL FILAMENTS; MULTICATALYTIC PROTEINASE; NEUROFIBRILLARY TANGLES; PROTEOLYTIC ACTIVITY; ALZHEIMERS-DISEASE; PRECURSOR PROTEIN; UBIQUITIN; DEGRADATION; CELL; SUBSTRATE AB Neurodegenerative disorders of aging are characterized by the intraneuronal accumulation of ubiquitin conjugates into tangles and inclusions. Ubiquitin conjugates are degraded by cellular particles known as proteasomes. We have previously shown that amyloid beta protein (A beta) inhibits proteasomal activity and thereby blocks ubiquitin conjugate degradation. In the present studies, we found that A beta binds the 20 S proteasome and forms a proteasome-A beta complex. The complex was detected by Western blot with anti-A beta antibodies. Using a 1.4 nm Nanogold-labeled A beta, we visualized proteasome-A beta complexes by scanning transmission electron microscopy (STEM). Analysis of the side-on oriented proteasome-A beta complexes revealed a single gold particle, corresponding to one gold-labeled A beta, in the middle portion of the proteasome. On end-on views of proteasome-A beta complexes, gold was detected within the area delimited by the proteasome circular projection. Both STEM views are consistent with A beta localization inside the proteasome along the peptide channel. Direct interaction of A beta with the inner catalytic compartment of the proteasome may explain the generation of ubiquitin-containing lesions in Alzheimer's disease and other neurodegenerative disorders. In addition, detection of Nanogold-labeled peptide inside the 20 S eukaryotic proteasome suggests that conformational constraints for protein degradation in eukaryotic proteasomes are different from those in archaebacteria proteasomes. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. RP Gregori, L (reprint author), SUNY STONY BROOK,SCH MED,HLTH SCI CTR T10,DEPT PSYCHIAT & BEHAV SCI,STONY BROOK,NY 11794, USA. NR 30 TC 111 Z9 113 U1 1 U2 5 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 3 PY 1997 VL 272 IS 1 BP 58 EP 62 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WA564 UT WOS:A1997WA56400014 PM 8995227 ER PT J AU Panofsky, WKH AF Panofsky, WKH TI Disposing of excess plutonium SO SCIENCE LA English DT Letter RP Panofsky, WKH (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 3 PY 1997 VL 275 IS 5296 BP 11 EP 12 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WA903 UT WOS:A1997WA90300002 ER PT J AU Loehle, C AF Loehle, C TI Responsibility of co-authors SO SCIENCE LA English DT Letter RP Loehle, C (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 0 TC 2 Z9 2 U1 1 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 3 PY 1997 VL 275 IS 5296 BP 14 EP 14 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WA903 UT WOS:A1997WA90300010 ER PT J AU Damrauer, NH Cerullo, G Yeh, A Boussie, TR Shank, CV McCusker, JK AF Damrauer, NH Cerullo, G Yeh, A Boussie, TR Shank, CV McCusker, JK TI Femtosecond dynamics of excited-state evolution in [Ru(bpy)(3)](2+) SO SCIENCE LA English DT Article ID INTERLIGAND ELECTRON-TRANSFER; SOLVATION DYNAMICS; CHARGE SEPARATION; ARTIFICIAL PHOTOSYNTHESIS; RUTHENIUM(II) COMPLEXES; POLYPYRIDINE COMPLEXES; MOLECULAR-LEVEL; METAL DIMERS; SPECTROSCOPY; TRANSITION AB Time-resolved absorption spectroscopy on the femtosecond time scale has been used to monitor the earliest events associated with excited-state relaxation in tris-(2,2'-bipyridine)ruthenium(II). The data reveal dynamics associated with the temporal evolution of the Franck-Condon state to the lowest energy excited state of this molecule. The process is essentially complete in similar to 300 femtoseconds after the initial excitation. This result is discussed with regard to reformulating long-held notions about excited-state relaxation, as well as its implication for the importance of non-equilibrium excited-state processes in understanding and designing molecular-based electron transfer, artificial photosynthetic, and photovoltaic assemblies in which compounds of this class are currently playing a key role. C1 UNIV CALIF BERKELEY, DEPT CHEM, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. RI Cerullo, Giulio/F-6534-2011; OI Cerullo, Giulio/0000-0002-9534-2702 NR 56 TC 444 Z9 444 U1 12 U2 129 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JAN 3 PY 1997 VL 275 IS 5296 BP 54 EP 57 DI 10.1126/science.275.5296.54 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WA903 UT WOS:A1997WA90300044 ER PT J AU Evans, JSO Hu, Z Jorgensen, JD Argyriou, DN Short, S Sleight, AW AF Evans, JSO Hu, Z Jorgensen, JD Argyriou, DN Short, S Sleight, AW TI Compressibility, phase transitions, and oxygen migration in zirconium tungstate, ZrW2O8 SO SCIENCE LA English DT Article ID BOND-VALENCE PARAMETERS; THERMAL-EXPANSION; POWDER AB In situ neutron diffraction experiments show that at pressures above 2 kilobars, cubic zirconium tungstate (ZrW2O8) undergoes a quenchable phase transition to an orthorhombic phase, the structure of which has been solved from powder diffraction data. This phase transition can be reversed by heating at 393 kelvin and 1 atmosphere and involves the migration of oxygen atoms in the lattice. The high-pressure phase shows negative thermal expansion from 20 to 300 kelvin. The relative thermal expansion and compressibilities of the cubic and orthorhombic forms can be explained in terms of the ''cross-bracing'' between polyhedra that occurs as a result of the phase transition. C1 OREGON STATE UNIV,DEPT CHEM,CORVALLIS,OR 97331. ARGONNE NATL LAB,DIV INTENSE PULSED NEUTRON SOURCE,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. RI Evans, John/E-6345-2012 OI Evans, John/0000-0001-6305-6341 NR 18 TC 261 Z9 300 U1 3 U2 63 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 3 PY 1997 VL 275 IS 5296 BP 61 EP 65 DI 10.1126/science.275.5296.61 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WA903 UT WOS:A1997WA90300047 ER PT J AU Yoo, CS Campbell, AJ Mao, HK Hemley, RJ AF Yoo, CS Campbell, AJ Mao, HK Hemley, RJ TI Detecting phases of iron - Response SO SCIENCE LA English DT Article ID EARTHS CORE; X-RAY; TEMPERATURES C1 CARNEGIE INST WASHINGTON,GEOPHYS LAB,WASHINGTON,DC 20015. GE SUPERABRAS,WORTHINGTON,OH 43085. RP Yoo, CS (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 6 TC 6 Z9 6 U1 0 U2 2 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 3 PY 1997 VL 275 IS 5296 BP 96 EP 96 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WA903 UT WOS:A1997WA90300059 ER PT J AU Hirsch, MT Duxstad, KJ Haller, EE AF Hirsch, MT Duxstad, KJ Haller, EE TI Effects of annealing on Ti Schottky barriers on n-type GaN SO ELECTRONICS LETTERS LA English DT Article DE gallium nitride; Schottky barriers; annealing AB The authors ivestigate the Schottky barrier heights of Ti films deposited on n-type GaN. The effective barrier height Phi(b0) is measured by current-voltage measurements, against temperature. An increasing barrier height Phi(b0) from similar to 200meV (as-deposited) to 250meV after annealing at temperatures as low as 60 degrees C is observed. After annealing at 230 degrees C and above, a stable Phi(b0) of 450meV is measured. The increase in Phi(b0) is not due to any macroscopic interfacial reaction. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Hirsch, MT (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 9 TC 29 Z9 30 U1 1 U2 2 PU IEE-INST ELEC ENG PI HERTFORD PA MICHAEL FARADAY HOUSE SIX HILLS WAY STEVENAGE, HERTFORD, ENGLAND SG1 2AY SN 0013-5194 J9 ELECTRON LETT JI Electron. Lett. PD JAN 2 PY 1997 VL 33 IS 1 BP 95 EP 96 DI 10.1049/el:19970021 PG 2 WC Engineering, Electrical & Electronic SC Engineering GA XL931 UT WOS:A1997XL93100064 ER PT J AU Lyman, JL Newnam, BE Early, JW vanderMeer, AFG AF Lyman, JL Newnam, BE Early, JW vanderMeer, AFG TI Infrared free-electron-laser photolysis of CFCl3 and CF2Cl2 SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID MULTIPLE-PHOTON ABSORPTION; ENERGY; SF6 AB A tunable infrared free-electron laser comprised of a train of picosecond pulses was utilized to destroy the Freons CFCl3 and CF2Cl2 by multiple-photon dissociation. The experiments explored the effects of laser frequency, laser fluence, spectral bandwidth, frequency chirping, reactant partial pressure, and oxygen (or air) partial pressure. We determined the optimum laser frequencies for dissociation of both of the Freons and also showed that a broader spectral bandwidth laser enhances reaction. A strong reduction of dissociation fraction with increasing pressure made infrared photodissociation of Freons at near atmospheric pressure difficult. Improvement of the high-pressure photolysis would require a laser macropulse much shorter than the 2 mu s used in these experiments. C1 EURATOM,FOM,INST PLASMA PHYS RIJNHUIZEN,NIEUWEGEIN,NETHERLANDS. RP Lyman, JL (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MS J567,LOS ALAMOS,NM 87545, USA. NR 32 TC 12 Z9 12 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 2 PY 1997 VL 101 IS 1 BP 49 EP 54 DI 10.1021/jp961739r PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL080 UT WOS:A1997WL08000008 ER PT J AU Hsu, CC Lin, MC Mebel, AM Melius, CF AF Hsu, CC Lin, MC Mebel, AM Melius, CF TI Ab initio study of the H+HONO reaction: Direct abstraction versus indirect exchange processes SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID DENSITY-FUNCTIONAL THERMOCHEMISTRY; POTENTIAL-ENERGY SURFACE; FREQUENCIES AB The mechanism of the H + HONO reaction (for which no experimental data are available) has been elucidated by ab initio molecular orbital calculations using modified G2 and BAC-MP4 methods. These results indicate that the reaction occurs predominantly by two indirect metathetical processes. One produces OH + HNO and H2O + NO from the decomposition of vibrationally excited hydroxyl nitroxide, HN(O)OH, formed by H atom addition to the N atom of HONO. The other produces H2O + NO from the decomposition of vibrationally excited dihydroxylamino radical, N(OH)(2), formed by H atom addition to the terminal O atom. These indirect displacement processes are much more efficient than the commonly assumed, direct H-abstraction reaction producing H-2 + NO2. A transition-state theory calculation for the direct abstraction reaction and RRKM calculations for the two indirect displacement processes give rise to the following rate constants,in units of cm(3) molecule(-1) s(-1) for the 300-3500 K temperature range under atmospheric conditions: k(H2) = 3.33 x 10(-16)T(1.55) exp(-3328.5/T), k(OH) = 9.36 x 10(-14)T(0.86) exp(-2500.8/T), k(H2O) = 1.35 x 10(-17)T(1.89) exp(-1935.7/T), where the rate constant for H2O production represents the sum from both indirect displacement reactions. C1 EMORY UNIV, DEPT CHEM, ATLANTA, GA 30322 USA. SANDIA NATL LABS, COMBUST RES FACIL, LIVERMORE, CA 94552 USA. RI Mebel, Alexander/A-5234-2009 NR 24 TC 27 Z9 28 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 2 PY 1997 VL 101 IS 1 BP 60 EP 66 DI 10.1021/jp962286t PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL080 UT WOS:A1997WL08000010 ER PT J AU Zaban, A Ferrere, S Sprague, J Gregg, BA AF Zaban, A Ferrere, S Sprague, J Gregg, BA TI pH-dependent redox potential induced in a sensitizing dye by adsorption onto TiO2 SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHARGE SEPARATION; SOLID-STATE; SEMICONDUCTOR; ELECTRODES; CELL; LIGHT; CONVERSION; INJECTION; FILMS; ZNO AB The oxidation potential of a ruthenium(II)-polypyridine sensitizing dye is independent of pH when the dye is dissolved in solution. However, when the dye is adsorbed onto nanocrystalline TiO2, its oxidation potential becomes pH-dependent, decreasing 53 mV per unit pH. This is approximately the same pH-dependence as followed by the flatband potential of the TiO2. Therefore, the driving forces for both forward and back electron transfer reactions are practically independent of pH. This may explain the pH-independent rate of back electron transfer recently observed by Yan and Hupp (J. Phys. Chem. 1996, 100, 6867). To our knowledge, the induction of a pH-dependent redox potential upon adsorption of an otherwise pH-independent dye has not been previously reported. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 21 TC 166 Z9 169 U1 0 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 2 PY 1997 VL 101 IS 1 BP 55 EP 57 DI 10.1021/jp962252l PG 3 WC Chemistry, Physical SC Chemistry GA WL102 UT WOS:A1997WL10200009 ER PT J AU Hughes, RJ AF Hughes, RJ TI Quantum security is spookily certain SO NATURE LA English DT Editorial Material ID KEY DISTRIBUTION; CRYPTOGRAPHY RP Hughes, RJ (reprint author), LOS ALAMOS NATL LAB,DIV PHYS,P-23,MS H803,LOS ALAMOS,NM 87545, USA. NR 13 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 2 PY 1997 VL 385 IS 6611 BP 17 EP 18 DI 10.1038/385017a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WA731 UT WOS:A1997WA73100018 ER PT J AU Barranco, F Broglia, RA Esbensen, H Vigezzi, E AF Barranco, F Broglia, RA Esbensen, H Vigezzi, E TI Role of finite nuclei on the pairing gap of the inner crust of neutron stars SO PHYSICS LETTERS B LA English DT Article DE pairing gap; neutron stars ID ENERGY GAPS; MATTER AB The state dependent pairing gap is calculated for a Wigner cell lying in the inner crust of a neutron star, allowing neutrons to interact through the Argonne v(14) potential. Although the values of the pairing gap will be renormalized by the induced interaction, the result found, that the pairing gap is sensitive to the presence of the finite atomic nucleus in the sea of free neutrons, is expected to be quite general. C1 UNIV MILAN,DIPARTIMENTO FIS,MILAN,ITALY. IST NAZL FIS NUCL,SEZ MILANO,I-20133 MILAN,ITALY. UNIV COPENHAGEN,NIELS BOHR INST,DK-2100 COPENHAGEN,DENMARK. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Barranco, F (reprint author), UNIV SEVILLA,DPT FIS APLICADA,ESCUELA SUPER INGN,SEVILLE,SPAIN. OI Barranco Paulano, Francisco/0000-0002-7799-2736 NR 25 TC 49 Z9 53 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 2 PY 1997 VL 390 IS 1-4 BP 13 EP 17 DI 10.1016/S0370-2693(96)01373-1 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD164 UT WOS:A1997WD16400003 ER PT J AU Krehl, O Rapp, R Speth, J AF Krehl, O Rapp, R Speth, J TI Meson-meson scattering: K(K)over-bar-tbresholds and f(0)(980)-a(0)(980) mixing SO PHYSICS LETTERS B LA English DT Article DE meson-meson scattering; meson exchange model; basis of mass eigenstates (particle basis); K(K)over-bar-thresholds; K(K)over-bar boundstate; pi(0)eta decay of f(0)(980); mixing of f(0)(980) and a(0)(980) AB We study the influence of mass splitting between the charged and neutral pions and kaons in the Julich meson exchange model for pi pi and pi eta scattering. The calculations are performed in the particle basis, which permits the use of physical masses for the pseudoscalar mesons and a study of the distinct thresholds associated with the neutral and the charged kaons. Within this model we also investigate the isospin violation which arises from the mass splitting and an apparent violation of G-parity in pi pi scattering which stems from the coupling to the K (K) over bar channel. Non-vanishing cross sections for pi pi --> pi(0) eta) indicate a mixing of the f(0)(980) and a(0)(980) states. C1 SUNY STONY BROOK, DEPT PHYS, STONY BROOK, NY 11794 USA. THOMAS JEFFERSON NATL ACCELERATOR FACIL, NEWPORT NEWS, VA 23606 USA. RP Krehl, O (reprint author), FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST KERNPHYS, D-52425 JULICH, GERMANY. NR 6 TC 56 Z9 57 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 JAN 2 PY 1997 VL 390 IS 1-4 BP 23 EP 28 DI 10.1016/S0370-2693(96)01425-6 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD164 UT WOS:A1997WD16400005 ER PT J AU Riotto, A Roulet, E Vilja, I AF Riotto, A Roulet, E Vilja, I TI Preheating and vacuum metastability in supersymmetry SO PHYSICS LETTERS B LA English DT Article ID LOW-ENERGY SUPERGRAVITY; PARTICLE-PRODUCTION; EARLY UNIVERSE; ENTROPY CRISIS; FALSE VACUA; INFLATION; BREAKING; EQUILIBRIUM; BARYOGENESIS; MODELS AB The constraints imposed by the requirement that the scalar potential of supersymmetric theories does not have unbounded directions and charge or color breaking minima deeper than the usual electroweak breaking minimum (EWM) are significantly relaxed if one just allows for a metastable EWM but with a sufficiently long lifetime. For this to be acceptable one needs however to explain how the vacuum state reaches this metastable configuration in the first place. We discuss the implications for this issue of the inflaton induced scalar masses, of the supersymmetry breaking effects generated during the preheating stage as well as of the thermal corrections to the scalar potential which appear after reheating. We show that their combined effects may efficiently drive the scalar fields to the origin, allowing them to then evolve naturally towards the EWM. C1 SCUOLA INT SUPER STUDI AVANZATI,SCH ADV INT STUDIES,I-34014 TRIESTE,ITALY. UNIV TURKU,DEPT PHYS,TURKU 20014,FINLAND. RP Riotto, A (reprint author), FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510, USA. NR 48 TC 12 Z9 12 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 JAN 2 PY 1997 VL 390 IS 1-4 BP 73 EP 79 DI 10.1016/S0370-2693(96)01380-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD164 UT WOS:A1997WD16400014 ER PT J AU Dorey, N Khoze, VV Mattis, MP AF Dorey, N Khoze, VV Mattis, MP TI Multi-instanton check of the relation between the prepotential F and the modulus u in N=2 SUSY Yang-Mills theory SO PHYSICS LETTERS B LA English DT Article AB By examining multi-instantons in N = 2 supersymmetric SU(2) gauge theory, we derive, on very general grounds, and to all orders in the instanton number, a relationship between the prepotential F(Phi), and the coordinate on the quantum moduli space u = (Tr Phi(2)). This relation was previously obtained by Matone in the context of the explicit Seiberg-Witten low-energy solution of the model. Our findings can be viewed as a multi-instanton check of the proposed exact results in supersymmetric gauge theory. C1 UNIV DURHAM,CTR PARTICLE THEORY,DEPT PHYS,DURHAM DH1 3LE,ENGLAND. LOS ALAMOS NATL LAB,DIV THEORET T8,LOS ALAMOS,NM 87545. RP Dorey, N (reprint author), UNIV COLL SWANSEA,DEPT PHYS,SWANSEA SA2 8PP,W GLAM,WALES. OI Khoze, Valentin V/0000-0003-3006-4147 NR 16 TC 48 Z9 48 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 JAN 2 PY 1997 VL 390 IS 1-4 BP 205 EP 209 DI 10.1016/S0370-2693(96)01427-X PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD164 UT WOS:A1997WD16400034 ER PT J AU Jadach, S Placzek, W Ward, BFL AF Jadach, S Placzek, W Ward, BFL TI BHWIDE 1.00: O(alpha) YFS exponentiated Monte Carlo for Bhabha scattering at wide angles for LEP1/SLC and LEP2 SO PHYSICS LETTERS B LA English DT Article ID FERMION PAIR PRODUCTION; HIGH-ENERGIES; MULTIPLE BREMSSTRAHLUNG; RADIATIVE-CORRECTIONS; PHOTON CORRECTIONS; EVENT GENERATOR; CROSS-SECTIONS; E+E COLLISIONS; GAUGE-THEORIES; SOFT PHOTONS AB We present O(alpha) YFS exponentiated results for wide angle Bhabha scattering at LEP/SLC energies using a new Monte Carlo event generator BHWIDE 1.xx. Our calculations include two options for the pure weak corrections, as presented in Beenakker et al, and in Bohm et al. From comparison with the results of Beenakker et al., Montagna et al. and Cacciari et al., we conclude that the total precision of our BHWIDE results is 0.3% (0.5%) in the LEP1/SLC regime within +/-100 MeV (+2.75/-2.5 GeV) of the Z peak. For LEP2, the corresponding precision is currently estimated at 1.5%; the latter could be improved if the data in LEP2 so require. Both precision tags represent clear improvements over what is currently available in the literature. C1 CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Jadach, S (reprint author), INST NUCL PHYS,UL KAWIORY 26A,KRAKOW,POLAND. NR 31 TC 281 Z9 283 U1 1 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 JAN 2 PY 1997 VL 390 IS 1-4 BP 298 EP 308 DI 10.1016/S0370-2693(96)01382-2 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD164 UT WOS:A1997WD16400048 ER PT J AU Dawson, S He, XG Valencia, G AF Dawson, S He, XG Valencia, G TI CP violation in W gamma and Z gamma production SO PHYSICS LETTERS B LA English DT Article ID ELECTRIC-DIPOLE MOMENT; NONCONSERVATION AB We study the capability of a 2 TeV p (p) over bar collider with an integrated luminosity of 10 fb(-1) to study CP violation in the processes p (p) over bar --> W(+/-)gamma and p (p) over bar --> Z gamma. We assume the existence of new CP violating interactions beyond the standard model which we describe with an effective Lagrangian. We find that the study of CP-odd observables would allow this machine to place bounds on CP violating anomalous couplings similar to the bounds that the same machine can place on CP conserving anomalous couplings. For example it could place the bound \<(kappa)over tilde>(gamma)\ < 0.1 at the 95% confidence level. C1 UNIV MELBOURNE,SCH PHYS,PARKVILLE,VIC 3052,AUSTRALIA. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. RP Dawson, S (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI He, Xiao-Gang/C-8894-2013; He, Xiao-Gang/P-2242-2015; OI Dawson, Sally/0000-0002-5598-695X NR 23 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 JAN 2 PY 1997 VL 390 IS 1-4 BP 431 EP 436 DI 10.1016/S0370-2693(96)01364-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WD164 UT WOS:A1997WD16400069 ER PT B AU Schwartz, M Elliott, D AF Schwartz, M Elliott, D GP AMS TI The integration of climatic data sets for wind resource assessment SO 10TH CONFERENCE ON APPLIED CLIMATOLOGY LA English DT Proceedings Paper CT 10th Conference on Applied Climatology CY OCT 20-23, 1997 CL RENO, NV SP Amer Meteorol Soc C1 Natl Renewable Energy Lab, NWTC, Golden, CO 80401 USA. RP Schwartz, M (reprint author), Natl Renewable Energy Lab, NWTC, 1617 Cole Blvd, Golden, CO 80401 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1997 BP 368 EP 372 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BK86P UT WOS:000073700700104 ER PT B AU Barr-Kumarakulasinghe, SA Pathiraja, K AF Barr-Kumarakulasinghe, SA Pathiraja, K GP AMS TI Automated Sri Lankan and south Indian monsoonal rainfall prediction and dissemination through the World Wide Web SO 10TH CONFERENCE ON APPLIED CLIMATOLOGY LA English DT Proceedings Paper CT 10th Conference on Applied Climatology CY OCT 20-23, 1997 CL RENO, NV SP Amer Meteorol Soc C1 Brookhaven Natl Lab, DAS, SISG, Upton, NY 11973 USA. RP Barr-Kumarakulasinghe, SA (reprint author), Brookhaven Natl Lab, DAS, SISG, Bldg 490D, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1997 BP 394 EP 395 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BK86P UT WOS:000073700700110 ER PT B AU Penetrante, BM AF Penetrante, BM BE Cooperstein, G Vitkovitsky, I TI Removal of NOX from diesel generator exhaust by pulsed electron beams SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The objective of this paper is to determine the effects of electron beam pulse parameters on the utilization of the reactive free radicals for removal of NOX from diesel generator exhaust. A dose per pulse less than 1 kGy has been determined to be optimum for effective radical utilization. During each post-pulse period, the radicals are utilized in the removal of NOX in a timescale of around 100 microseconds; thus, with pulse frequencies of around 10 kHz or less, the radical concentrations remain sufficiently low to prevent any significant competition between radical-pollutant and radical-radical reactions. It is shown that a pulsed electron beam reactor, operating with a dose per pulse of less than 1 kGy/pulse and pulse repetition rate of less than 10 kHz, will have the same plasma chemistry efficiency (parts per million of removed NOX per kGy of electron beam dose) as an electron beam reactor operating with a low dose rate of 50 kGy/s in continuous mode. Ozone accumulation is a limiting factor under high pulse frequency conditions. The total dose requirement determines the optimum combination of dose per pulse and pulse frequency for both radical utilization and prevention of ozone buildup. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Penetrante, BM (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave,Mailstop L-418, Livermore, CA 94550 USA. NR 0 TC 8 Z9 8 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 91 EP 96 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800004 ER PT B AU Korzekwa, R Rosocha, L Falkenstein, Z AF Korzekwa, R Rosocha, L Falkenstein, Z BE Cooperstein, G Vitkovitsky, I TI Experimental results comparing pulsed corona and dielectric barrier discharges for pollution control SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Nonthermal plasmas efficiently produce highly reactive chemical species for the destruction of pollutants in gaseous effluents. Two devices commonly used to produce a nonthermal plasma in atmospheric pressure gases are the pulsed corona reactor (PCR) and the dielectric barrier discharge reactor, also referred to as a "silent discharge plasma" (SDP) reactor. The PCR produces a nonthermal plasma by applying a fast-rising, short duration, high-voltage pulse to a coaxial wire/tube geometry which initiates multiple streamers (electron avalanches) along the length of the tube. The high-energy electrons produced in the streamers create the desired active species (e.g., radicals) while maintaining near ambient neutral gas temperatures. The streamers are extinguished as the energy is depleted in the storage capacitance. The SDP reactor is constructed using either a coaxial or flat-plate electrode geometry with a least one dielectric barrier placed between the high-voltage electrodes, leaving a few millimeter gap in which the nonthermal plasma is generated. When the breakdown voltage is reached in the gas gap, microdischarge streamers are produced throughout the gap volume which self-terminate when the build up of surface charge on the dielectric reduces the electric field in the gap. Although a fast rising pulse can be used to drive an SDP reactor, a sinusoidal voltage with a frequency of a few kilohertz is typically used to drive this type of reactor. When a fast-rising voltage pulse is used to drive these reactors, a higher reduced electric field strength (E/N) can be obtained than in the low-frequency-driven SDP reactors. In many cases a higher E/N results in a more efficient production of chemical radicals, which in turn interact with and destroy the low concentration pollutants in the gas. Commercially available power supplies are commonly used to drive the low frequency SDP reactor systems. These provide a simple and robust method of producing a nonthermal plasma for high power applications without the complexity of fast risetime, high-voltage switching circuits. A comparison of the results obtained in these devices is presented for various operating conditions and gas pollutants. Our primary interest is to explore whether the added complexity of fast risetime circuits has a payoff in terms of overall chemical-processing efficiency. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Korzekwa, R (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,E-525, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 97 EP 102 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800005 ER PT B AU Turman, BN Glass, SJ Halbleib, JA Voth, TE Gerstle, FP Yang, P McKenzie, B Clifford, JR AF Turman, BN Glass, SJ Halbleib, JA Voth, TE Gerstle, FP Yang, P McKenzie, B Clifford, JR BE Cooperstein, G Vitkovitsky, I TI High energy electron beam joining of ceramic components SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB High strength, hermetic braze joints between ceramic components have been produced using high energy electron beams. With a penetration depth into a typical ceramic of similar to 1 cm for a 10 MeV electron beam, this method provides the capability for rapid, transient brazing operations where temperature control of critical components is essential. The method deposits energy directly into a buried joint, allowing otherwise inaccessible interfaces to be brazed. Because of transient heating, higher thermal conductivity, lower heat capacity, and lower melting temperature of braze metals relative to the ceramic materials, a pulsed high power beam can melt a braze metal without producing excessive ceramic temperatures. We have demonstrated the feasibility of this process related to ceramic coupons as well as ceramic and glass tubes. The transient thermal response was predicted, using as input the energy absorption predicted from the coupled electron-photon transport analysis. The joining experiments were conducted with an RF Linac accelerator at 10-13 MV. The repetition rate of the pulsed beam was varied between 8 and 120 Hz, the average beam current was varied between 8 and 120 microamps, and the Fewer was varied up to 1.5 kW These beam parameters gave a beam power density between 0.2 to 2 kW/cm(2). The duration of the joining runs varied from 5 to 600 sec. Joining experiments have provided high strength between alumina - alumina and alumina - cermet joints in cylindrical geometry. These joints provided good hermetic seals. A series of tests was conducted to determine the minimum beam power and exposure time for producing a hermetic seal. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Turman, BN (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 115 EP 120 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800008 ER PT B AU Struve, KW Martin, TH Spielman, RB Stygar, WA Corcoran, PA Douglas, JW AF Struve, KW Martin, TH Spielman, RB Stygar, WA Corcoran, PA Douglas, JW BE Cooperstein, G Vitkovitsky, I TI Circuit-code modeling of the PBFA Z for Z-pinch experiments SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The SCREAMER(1) and the TL2 codes were used to design the z-pinch modification of PBFA II, which is now called Z. Tn the design phase an equivalent voltage was used to initiate the simulations. Good agreement between the measured waveforms and design simulations has been achieved. Recently, full-circuit, shortened-circuit, and equivalent-circuit simulations have been used. All use a loss model that discards the plasma current in the vacuum magnetically insulated transmission lines (MITL's) at the post hole convolute (PHC). Voltage measurements provide an equivalent voltage which is used as a starting point for four-level circuit and equivalent-circuit simulations. Both fill-circuit and shortened-circuit simulations use a four-line model. The thirty-six lines are lumped into four, nine-line equivalent circuits. The full circuit includes the erected Man: bank, the intermediate store water capacitor, the laser-triggered spark gap, the line 1, 2 and 3 pulse forming lines, the coax to biplate transition, the water biplates, the vacuum stack with water and vacuum flares, the MITL's, the PHC, and the z-pinch load. Because of the difficulty in making load current measurements, the model has been used to infer load current and implosion characteristics. The model has also been used to predict optimal pinch load configurations. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Struve, KW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 10 Z9 10 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 162 EP 167 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800015 ER PT B AU Renk, TJ Buchheit, RG Sorensen, NR Senft, DC Thompson, MO AF Renk, TJ Buchheit, RG Sorensen, NR Senft, DC Thompson, MO BE Cooperstein, G Vitkovitsky, I TI Surface treatment and alloying with high-power ion beams to improve properties in Al-, Fe-, and Ti-based metals SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Intense pulsed high-power ion beams have been demonstrated to produce enhanced surface properties by changes in microstructure caused by rapid heating and cooling of the surface. Additional improvements can be effected by the mixing of a previously deposited thin-film layer (surface alloying or ion beam mixing) into any number of substrate materials. We have conducted surface treatment and alloying experiments with Al, Fe, and Ti-based metals on the RHEPP-1 accelerator (0.8 MV, 20 Omega, 80 ns FHWM, up to 1 Hz repetition rate) at Sandia National Laboratories. Ions are generated by the MAP gas-breakdown active anode, which can yield a number of different beam species including Ii, N, and Xe, depending upon the injected gas. Enhanced hardness and wear resistance have been produced by treatment: of 440C stainless steel, and by the mixing of Pt into Ti-6AL-4V alloy. Mixing of a thin-film Hf layer into Al 6061-T6 alloy (Al-1.0Mg-0.6Si) has improved its corrosion resistance by as much as four orders of magnitude in electrochemical testing, compared with untreated and uncoated Al6061. Experiments are angering to further understand the microstructural basis far these surface improvements. C1 Sandia Natl Labs, Ithaca, NY 14853 USA. RP Renk, TJ (reprint author), Sandia Natl Labs, Ithaca, NY 14853 USA. OI Grabowski, Kenneth/0000-0003-0816-001X; Thompson, Michael/0000-0002-4933-009X NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 192 EP 197 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800018 ER PT B AU Goerz, DA Wilson, MJ Speer, RD AF Goerz, DA Wilson, MJ Speer, RD BE Cooperstein, G Vitkovitsky, I TI A low-profile high-voltage compact gas switch SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB This paper discusses the development acid testing of a low-profile, high-voltage spark-gap switch designed to be closely coupled with other components into an integrated high-energy pulsed-power source. The switch is designed to operate at 100 kV using SF6 gas pressurized to less than 0.7 MPa. The volume of the switch cavity region is less than 1.5 cm(3), and the field stress along the gas-dielectric interface is as high as 130 kV/cm. The dielectric switch body has a low profile that is only l-cm tall at its greatest extent and nominally 2-mm thick over most of its area. This design achieves a very low inductance of less than 5 nH, but results in field stresses exceeding 500 kV/cm in the dielectric material. Field modeling was done to determine the appropriate shape for the highly stressed insulator and electrodes, and special manufacturing techniques were employed to mitigate the usual mechanisms that induce breakdown and failure in solid dielectrics. Static breakdown tests verified that the switch operates satisfactorily at 100 kV levels. The unit has been characterized with different shaped electrodes having nominal gap spacings of 2.0, 2.5, and 3.0 mm. The relationship between self-break voltage and operating pressure agrees well with published data on gas properties, accounting for the field enhancements of the electrode shapes being used. Capacitor discharge tests in a low inductance test fixture exhibited peak currents up to 25 kA with characteristic frequencies of the ringdown circuit ranging from 10 ta 20 MHz. The ringdown waveforms and scaling of measured parameters agree well with circuit modeling of the switch and test fixture. Repetitive operation has been demonstrated at moderate rep-rates up to 15 Hz, limited by the power supply being used. Preliminary tests to evaluate lifetime of the compact switch assembly have been encouraging. In one case, after more than 7,000 high-current ringdown tests with approximately 30 C of total charge transferred, the switch continued to operate satisfactorily with no apparent tracking or deterioration of the insulator. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Goerz, DA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-153, Livermore, CA 94550 USA. NR 0 TC 2 Z9 4 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 328 EP 333 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800040 ER PT B AU Shlachter, JS Adams, PJ Atchison, WL Bartsch, RR Benage, JF Cochrane, JC Coulter, WL Ekdahl, CA Faehl, RJ Fulton, RD Guzik, J Holtkamp, D Jones, ME Keinigs, R King, NSP Kyrala, GA Lee, H Lindemuth, IR Morgan, DV Moses, RW Obst, AW Oona, H Oro, D Parsons, WM Platts, D Reinovsky, RE Rodriguez, G Scudder, DW Sheppard, M Sorenson, DS Stokes, JL Taylor, A Trainer, RJ Watt, RG Wurden, GA AF Shlachter, JS Adams, PJ Atchison, WL Bartsch, RR Benage, JF Cochrane, JC Coulter, WL Ekdahl, CA Faehl, RJ Fulton, RD Guzik, J Holtkamp, D Jones, ME Keinigs, R King, NSP Kyrala, GA Lee, H Lindemuth, IR Morgan, DV Moses, RW Obst, AW Oona, H Oro, D Parsons, WM Platts, D Reinovsky, RE Rodriguez, G Scudder, DW Sheppard, M Sorenson, DS Stokes, JL Taylor, A Trainer, RJ Watt, RG Wurden, GA BE Cooperstein, G Vitkovitsky, I TI Pegasus II experiments and plans for the Atlas pulsed power facility SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Atlas will be a high-energy (36 MJ stored), high-power (similar to 10 TW) pulsed power driver for high energy-density experiments, with an emphasis on hydrodynamics. Scheduled for completion in late 1999, Atlas is designed to produce currents in the 40-50 MA range with a quarter-cycle cycle time of 4-5 mu s. It will drive implosions of heavy liners (typically 50 g) with implosion velocities exceeding 20 mm/mu s. Under these conditions very high pressures and magnetic fields are produced. Shock pressures in the 50 Mbar range and pressures exceeding 10 Mbar in an adiabatic compression will be possible. By performing flux compression of a seed field, axial magnetic fields in the 2000 T range may be achieved. A variety of concepts have been identified for the first experimental campaigns on Atlas. These experiments include Rayleigh-Taylor instability studies, convergent (e.g., Bell-Plesset type) instability studies, material strength experiments at very high strain and strain rate, hydrodynamic flows in 3-dimensional geometries, equation of state measurements along the hugoniot and adiabats, transport and shock propagation in dense strongly-coupled plasmas, and atomic and condensed matter studies employing ultra-high magnetic fields. Experimental configurations, associated physics issues, and diagnostic strategies are all under investigation as the design of the Atlas facility proceeds. Near-term proof-of-principle experiments employing the smaller Pegasus II capacitor bank have been identified, and several of these experiments have now been performed. This paper discusses a number of recent Pegasus II experiments and identifies several areas of research presently planned on Atlas. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Shlachter, JS (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Wurden, Glen/A-1921-2017; Rodriguez, George/G-7571-2012 OI Wurden, Glen/0000-0003-2991-1484; Rodriguez, George/0000-0002-6044-9462 NR 0 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 361 EP 365 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800045 ER PT B AU Lee, H Bartsch, RR Bowers, RL Anderson, W Atchison, WL Chrien, RE Cochrane, J Oona, H Platts, D Rich, M Shanahan, WR Scudder, DW Stokes, J Veeser, L AF Lee, H Bartsch, RR Bowers, RL Anderson, W Atchison, WL Chrien, RE Cochrane, J Oona, H Platts, D Rich, M Shanahan, WR Scudder, DW Stokes, J Veeser, L BE Cooperstein, G Vitkovitsky, I TI Liner experiments on Pegasus II SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Using pulsed power to implode a liner onto a target can produce high shock pressures for many interesting application experiments. With the Pegasus II facility in Los Alamos, a detailed theoretical analysis has indicated that the highest attainable pressure is around 2 Mbar for a best designed aluminium liner. This liner design was interesting composite Liner design has been proposed which can boost the shock pressure performance by a factor 4 over the aluminum liner. This liner design was adopted in the first megabar (Megarbar-1) liner experiment carried out on Pegasus last year to verify the design concept and to compare the effect of Rayleigh-Taylor instabilities on liner integrity with the code simulations. We present briefly the physical explanation why the composite liner provides the best shock pressure performance. The theoretical modeling and performance of Megabar-1 liner are discussed. Also presented are the first experimental results and the liner design modification for our next experiment. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lee, H (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 366 EP 371 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800046 ER PT B AU Atchison, WL Faehl, RJ Reinovsky, RE AF Atchison, WL Faehl, RJ Reinovsky, RE BE Cooperstein, G Vitkovitsky, I TI Evaluation of magneto Rayleigh-Taylor mode growth using comparisons of 2D calculations with radiographic data SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Experiments being conducted at the Los Alamos National Laboratory Pegasus facility are examining stability issues for driving an aluminum liner with a pulsed magnetic field. The Pegasus facility provides a current of 5 to 8 Megamperes to compress a cylindrical liner. Liners of various size and thickness are used, depending on the specific experimental objectives. In several of these experiments, the outer surface clearly develops perturbations in the mass distribution, These perturbations are strangest when the aluminum is suspected to have melted and in some cases partially vaporized. A series of specific experiments was designed to examine the growth rate of these instabilities. These experiments involved machining a sine wave onto the outer surface of the liner to seed a given wavelength. Two-dimensional MHD calculations, using the measured current profile, were performed to model the behavior of the liner under magnetic field compression. These predictions were made with a 2D Eulerian code complete with a Steinberg-Guinan strength model. The results of these calculations will be discussed in this paper. The density contours at specific times will be compared with the processed radiography. C1 Univ Calif Los Alamos Natl Lab, Plasma Applicat Grp, Los Alamos, NM 87545 USA. RP Atchison, WL (reprint author), Univ Calif Los Alamos Natl Lab, Plasma Applicat Grp, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 372 EP 377 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800047 ER PT B AU Reinovsky, RE Anderson, BG Clark, DA Ekdahl, CA Faehl, RJ Goforth, JH Lindemuth, IR Petersen, TL Sheehey, PT Tabaka, LJ Chernyshev, VK Mokhov, VN Buzin, VN Byrenkov, OM Bujko, AM Vakhruchev, VV Garanin, SF Grinevich, BE Gorbachev, YN Gubkov, EV Demidov, VA Dudoladov, VI Zmushko, VV Kuzyaev, AI Kucherov, AI Lovyagin, BM Matsev, YI Nizovtsev, PN Petrukhin, AA Pishurov, AI Sokolov, SS Solovjov, VP Startsev, AI Yakubov, VB AF Reinovsky, RE Anderson, BG Clark, DA Ekdahl, CA Faehl, RJ Goforth, JH Lindemuth, IR Petersen, TL Sheehey, PT Tabaka, LJ Chernyshev, VK Mokhov, VN Buzin, VN Byrenkov, OM Bujko, AM Vakhruchev, VV Garanin, SF Grinevich, BE Gorbachev, YN Gubkov, EV Demidov, VA Dudoladov, VI Zmushko, VV Kuzyaev, AI Kucherov, AI Lovyagin, BM Matsev, YI Nizovtsev, PN Petrukhin, AA Pishurov, AI Sokolov, SS Solovjov, VP Startsev, AI Yakubov, VB BE Cooperstein, G Vitkovitsky, I TI HEL-1: A DEMG based demonstration of solid liner implosions at 100MA SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Reinovsky, RE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 378 EP 383 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800048 ER PT B AU Veeser, LR Ekdahl, CA Oona, H Rodriguez, PJ Solem, JC Younger, SM Lewis, W Turley, WD Bykov, AI Aseeva, VV Boriskov, GV Dolotenko, MI Egorov, NI Kolokol'chikov, NP Kuropatkin, YP Mironenko, VD Pavlov, VN Volkov, AA AF Veeser, LR Ekdahl, CA Oona, H Rodriguez, PJ Solem, JC Younger, SM Lewis, W Turley, WD Bykov, AI Aseeva, VV Boriskov, GV Dolotenko, MI Egorov, NI Kolokol'chikov, NP Kuropatkin, YP Mironenko, VD Pavlov, VN Volkov, AA BE Cooperstein, G Vitkovitsky, I TI Isentropic compression of argon SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Veeser, LR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 384 EP 389 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800049 ER PT B AU Loubriel, GM Zutavern, FJ Mar, A O'Malley, MW Helgeson, WD Brown, DJ Hjalmarson, HP Baca, AG AF Loubriel, GM Zutavern, FJ Mar, A O'Malley, MW Helgeson, WD Brown, DJ Hjalmarson, HP Baca, AG BE Cooperstein, G Vitkovitsky, I TI Longevity of optically activated, high gain GaAs photoconductive semiconductor switches SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The longevity of high gain GaAs photoconductive semiconductor switches (PCSS) has been extended to well over 10 million pulses by reducing the density of carriers at the semiconductor to metal interface. This was achieved by reducing the density in the vertical and lateral directions. The first was achieved by varying the spatial distribution of the trigger light thereby widening the current filaments that are characteristic of the high gain switches. We reduced the carrier density in the vertical direction by using ion implantation. These results were obtained for currents of about 10 A, current duration of 3.5 ns, and switched voltage of similar to 2 kV. At currents of similar to 70 A, the switches last for 0.6 million pulses. In order to improve the performance at high currents new processes such as deep diffusion and epitaxial growth of contacts are being pursued. To guide this effort we measured a 6 x 10(18) electrons (or holes)/cm(3) in filaments that carry a current of 5A. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Loubriel, GM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 405 EP 413 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800052 ER PT B AU Ong, M Avalle, C Richardson, R Zentler, J AF Ong, M Avalle, C Richardson, R Zentler, J BE Cooperstein, G Vitkovitsky, I TI LLNL flash x-ray radiography machine (FXR) double-pulse upgrade diagnostics SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB When the FXR machine was first tuned on the 1980's, a minimal amount of diagnostics was available and consisted mostly of power monitors. During the recent accelerator upgrade, additional beam diagnostics were added. The sensor upgrades included beam bugs (resistive wall beam motion sensors) and high-frequency B-dof. Even with this suite of measurement tools, tuning was difficult. For the current Double-Pulse Upgrade, beam transport is a more complex problem-the beam characteristics must be measured better. Streak and framing cameras, which measure beam size and motions, are being added. Characterization of the beam along the entire accelerator is expected and other techniques will be evaluated also. Each sensor has limitations and only provides a piece of the puzzle. Besides providing more beam data, the set of diagnostics used should be broad enough so results can be cross validated. Results will also be compared to theoretical calculations and computer models, and successes and difficulties will be reported. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Ong, M (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 430 EP 435 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800056 ER PT B AU Rodriguez, G Roberts, JP Taylor, AJ Gallegos, CM AF Rodriguez, G Roberts, JP Taylor, AJ Gallegos, CM BE Cooperstein, G Vitkovitsky, I TI Development of an high pressure diagnostic based on optical Raman backscatter measurements in diamond SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB High pressure diagnostics for pulsed power high energy density physics experiments require time-resolved measurements under shock loading conditions with pressures exceeding a megabar. A high pressure diagnostic based on the optical Raman spectrum in oriented crystalline diamond is discussed. By placing the diamond probe in a preferred crystallographic orientation, shock loading due to the pressure wave induces a crystal strain proportional to the applied stress. A strain induced optical frequency shift in the Raman spectrum of diamond is measured temporally with a streak camera to permit real time determination of the pressure wave amplitude. Diamond Raman should provide a first step in achieving a high pressure probe standard for shock loading conditions and large density compression studies exceeding megabar stresses. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rodriguez, G (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 442 EP 447 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800058 ER PT B AU Obst, AW Fulton, D King, NSP Morgan, D Oro, D Platts, D Sorenson, DS Stelts, M AF Obst, AW Fulton, D King, NSP Morgan, D Oro, D Platts, D Sorenson, DS Stelts, M BE Cooperstein, G Vitkovitsky, I TI Performance of the multi-pulse x-ray imaging system for the pulsed power hydrodynamic experiments at LANL SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Pulsed power driven cylindrical shock physics experiments are being performed at the PEGASUS facility at Los Alamos National Laboratory. A time dependent, axial x-ray imaging capability farms a subset of the measurements to quantify material behavior during shock propagation. 20 ns pulsed W target x-ray sources with about 10 mR @ 1m form the backlighter. Inorganic scintillators generate time dependent, visible images, which are relayed to a shuttered, microchannel plate intensifier imaging system coupled to electronic video readouts. The dynamic range, sensitivity, scene contrast, and system spatial resolution are optimized to specific experiments via optimization of fluor response to both x-ray energy and light output time response, in addition, a series of calibration data are taken to permit characterizing density information through postevent image processing. This dataset includes flat field and step wedge images. The flat field is particularly important due to the relatively large spatial variation in the x-ray dose resulting from the close proximity (60cm) of the source to the imager. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Obst, AW (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 448 EP 453 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800059 ER PT B AU Bowman, DW Bennett, G Biehl, F Cochrane, J Gribble, R Griego, J Hicks, R Hinckley, W Hosack, K Kasik, R Lopez, E Reass, B Salazar, H Sandoval, G Scudder, D Thompson, MC Parsons, WM AF Bowman, DW Bennett, G Biehl, F Cochrane, J Gribble, R Griego, J Hicks, R Hinckley, W Hosack, K Kasik, R Lopez, E Reass, B Salazar, H Sandoval, G Scudder, D Thompson, MC Parsons, WM BE Cooperstein, G Vitkovitsky, I TI Design of the Atlas 240 kV Marx modules SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB A prototype 240 kV, oil-insulated Marx module has been designed and constructed at the Los Alamos National Laboratory (LANL). The prototype will be used for testing and certifying the design of the Man; module and certain components, including the closing switches, series resistor, and the capacitors themselves, The prototype will also be used to evaluate proposed mechanical systems designs. Information gained from the construction and testing of the LC-capacitor prototype will be folded into the design of the 16-capacitor maintenance unit. The prototype module consists of four 60 kV capacitors, two closing switches, one shunt resistor, and one series resistor. Cables are used to deliver the current to a dummy load scaled to match Atlas system parameters. The Marx unit is contained in a structure made from G-10, suspended from a steel frame that also serves to support components of the trigger, charging, and control system. Appropriate safety and charging systems are an integral part of the prototype design. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bowman, DW (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 498 EP 502 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800066 ER PT B AU Goforth, JH Atchison, WL Bartram, DE Fowler, CM Goettee, JD Herrera, DH King, JC Lopez, EA Martinez, EC Oona, H Reinovsky, RE Sheppard, MG Stokes, JL Tabaka, LJ Torres, DT AF Goforth, JH Atchison, WL Bartram, DE Fowler, CM Goettee, JD Herrera, DH King, JC Lopez, EA Martinez, EC Oona, H Reinovsky, RE Sheppard, MG Stokes, JL Tabaka, LJ Torres, DT BE Cooperstein, G Vitkovitsky, I TI The Ranchero explosive pulsed power system SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Goforth, JH (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Goettee, Jeffrey/L-4926-2015 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 573 EP 578 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800078 ER PT B AU Stygar, WA Spielman, RB Allshouse, GO Deeney, C Humphreys, DR Ives, HC Long, FW Martin, TH Matzen, MK McDaniel, DH Mendel, CW Mix, LP Nash, TJ Poukey, JW Ramirez, JJ Sanford, TWL Seamen, JF Seidel, DB Smith, JW Van de Valde, DM Wavrik, RW Corcoran, PA Douglas, JW Smith, ID Mostrom, MA Struve, KW Hughes, TP Clark, RE Shoup, RW Wagoner, TC Gilliland, TL Peyton, BP AF Stygar, WA Spielman, RB Allshouse, GO Deeney, C Humphreys, DR Ives, HC Long, FW Martin, TH Matzen, MK McDaniel, DH Mendel, CW Mix, LP Nash, TJ Poukey, JW Ramirez, JJ Sanford, TWL Seamen, JF Seidel, DB Smith, JW Van de Valde, DM Wavrik, RW Corcoran, PA Douglas, JW Smith, ID Mostrom, MA Struve, KW Hughes, TP Clark, RE Shoup, RW Wagoner, TC Gilliland, TL Peyton, BP BE Cooperstein, G Vitkovitsky, I TI Design and performance of the Z magnetically-insulated transmission lines SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB We have designed and tested a 10-nH 1.5-m-radius vacuum section for the Z accelerator. The vacuum section consists of four vacuum flares, four conical 1.3-m-radius magnetically-insulated transmission lines, a 7.6-cm-radius 12-post double-post-hole convolute which connects the four outer MITLs in parallel, and a 5-cm-long inner MITL which connects the output of the convolute to a z-pinch load. IVORY and ELECTRO calculations were performed to minimize the inductance of the vacuum flares with the constraint that there be no significant electron emission from the insulator-stack grading rings. Iterative TLCODE calculations were performed to minimize the inductance of the outer MITLs with the constraint that the MITL electron-flow-current fraction be less than or equal to 7% at peak current. The TLCODE simulations assume a 2.5 cm/mu s MITL-cathode-plasma expansion velocity. The design limits the electron dose to the outer-MITL anodes to 50 J/g to prevent the formation of an anode plasma. The TLCODE results were confirmed by SCREAMER TRIFL, TWOQUICK, IVORY, and LASNEX simulations. For the TLCODE, SCREAMER, and TRIFL calculations, we assume that after magnetic insulation is established, the electron-flow current launched in the outer MITLs is lost at the convolute. This assumption has been validated by 3-D QUICKSILVER simulations for load impedances less than or equal to 0.36 ohms. LASNEX calculations suggest that the ohmic resistance of the pinch and conduction-current-induced energy loss to the MITL electrodes can be neglected in Z-power-flow modeling that is accurate to first order. To date, the Z vacuum section has been tested on 100 shots. We have demonstrated we can deliver a 100-ns rise-time 20-MA current pulse to the baseline z-pinch load. We have produced a 1.9-MJ x-ray yield; the project goal was 1.5 MJ. We can reproduce the peak MITL current to within +/-1.6%. Power-flow measurements indicate the vacuum section performs as expected until peak current. Afterward, measurements and simulation results diverge. TLCODE calculations indicate elimination of this discrepancy may increase by 20% the kinetic energy delivered to the pinch. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Stygar, WA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 3 Z9 5 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 591 EP 596 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800081 ER PT B AU Scarpetti, RD Boyd, JK Earley, GG Griffin, KL Kerr, RG Kihara, R Ong, MM Zentler, JM Back, NL AF Scarpetti, RD Boyd, JK Earley, GG Griffin, KL Kerr, RG Kihara, R Ong, MM Zentler, JM Back, NL BE Cooperstein, G Vitkovitsky, I TI Upgrades to the LLNL flash x-ray induction linear accelerator (FXR) SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The FXR is an induction linear accelerator used for flash radiography at the Lawrence Livermore National Laboratory's Site 300 Test Facility. The FXR was originally completed in 1982 and has been in continuous use as a radiographic tool. At that time the FXR produced a 17 MeV, 2.2 kA burst of electrons for a duration of 65 ns. An upgrade of the FXR was recently completed. The purpose of this upgrade was to improve the performance of the FXR by increasing the energy of the electron injector from 1.2 MeV to 2.5 MeV and the beam current from 2.2 kA to 3 kA, improving the magnetic transport system by redesigning the solenoidal transport focus coils, reducing the rf coupling of the electron beam to the accelerator cells, and by adding additional beam diagnostics. We will describe the injector upgrades and performance, as well as our efforts to tune the accelerator by minimizing beam corkscrew motion and the impact of Beam Breakup Instability on beam centroid motion throughout the beam line as the current is increased to 3 kA. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Scarpetti, RD (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 597 EP 602 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800082 ER PT B AU Chen, YJ Caporaso, G AF Chen, YJ Caporaso, G BE Cooperstein, G Vitkovitsky, I TI Designs for a high power superconducting delay line SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Potential designs for a high power superconducting delay line of approximately 10 Ls duration are described. The transmitted signal should have low dispersion and little attenuation to recapture the original signal. Such demands cannot be met using conventional metal conductors. This paper outlines a proposal for a new transmission line design using low temperature superconducting material which meets system specifications. The 25 Omega line is designed to carry pulsed signals with an approximate rise time of 8nsec and a maximum voltage magnitude of 25kV. Predicted electrical design and performance of the line will be presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Chen, YJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 621 EP 626 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800086 ER PT B AU Mazarakis, MG Poukey, JW Maenchen, JE Rovang, DC Menge, PR Lash, JS Smith, DL Johnson, DL Halbleib, JA Cordova, SR Mikkelson, K Gustwiller, J Stygar, WA Welch, DR Smith, I Corcoran, P AF Mazarakis, MG Poukey, JW Maenchen, JE Rovang, DC Menge, PR Lash, JS Smith, DL Johnson, DL Halbleib, JA Cordova, SR Mikkelson, K Gustwiller, J Stygar, WA Welch, DR Smith, I Corcoran, P BE Cooperstein, G Vitkovitsky, I TI Inductive voltage adder (IVA) for submillimeter radius electron beam SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB We have already demonstrated the utility of inductive voltage adder accelerators for production of small-size electron beams. In our approach, the inductive voltage adder drives a magnetically immersed foilless diode to produce high-energy (10-20 MeV), high-brightness pencil electron beams. This concept was first demonstrated with the successful experiments which converted the linear induction accelerator RADLAC II1 into an TVA fitted with a small I-cm radius cathode magnetically immersed foilless diode (RADLAC II/SMILE).(2) We present here first validations of extending this idea to mm-scale electron beams using the SABRE(3) and HERMES-III4 inductive voltage adders as test beds. The SABRE experiments are already completed and have produced 30-kA, 9-MeV electron beams with envelope diameter of 1.5-mm FWHM. The KERMES-III experiments are currently underway. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Mazarakis, MG (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 642 EP 650 PG 9 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800089 ER PT B AU Parsons, WM Baldwin, CC Ballard, EO Bartsch, RR Benage, JF Bennett, GA Bowman, DW Cochrane, JC Creager, J Davis, HA Ekdahl, CA Gribble, RF Griego, JR Hinckley, WB Hosack, KW Kasik, RJ Keinigs, R Kimerly, HJ Lopez, EA Marquez, A Monroe, MD Ney, SA Pierce, DD Platts, D Reass, WA Salazar, HR Sandoval, GM Scudder, DW Shlachter, JS Thompson, MC Trainor, RJ Valdez, GA Watt, RG Wurden, GA Wysocki, FJ Younger, SM AF Parsons, WM Baldwin, CC Ballard, EO Bartsch, RR Benage, JF Bennett, GA Bowman, DW Cochrane, JC Creager, J Davis, HA Ekdahl, CA Gribble, RF Griego, JR Hinckley, WB Hosack, KW Kasik, RJ Keinigs, R Kimerly, HJ Lopez, EA Marquez, A Monroe, MD Ney, SA Pierce, DD Platts, D Reass, WA Salazar, HR Sandoval, GM Scudder, DW Shlachter, JS Thompson, MC Trainor, RJ Valdez, GA Watt, RG Wurden, GA Wysocki, FJ Younger, SM BE Cooperstein, G Vitkovitsky, I TI An overview of the Atlas pulsed-power systems SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Atlas is a facility being designed at Los Alamos National Laboratory (LANL) to perform high energy-density experiments in support of weapon-physics and basic-research programs. It is designed to be an international user facility, providing experimental opportunities to researchers from national laboratories and academic institutions. For hydrodynamic experiments, it will be capable of achieving pressures exceeding 20-Mbar in a several cm(3) volume. With the development of a suitable opening switch, it will also be capable of producing soft x-rays. The 36-MJ capacitor bank will consist of 240-kV Marx modules arranged around a central target chamber. The Marx modules will be discharged through vertical triplate transmission lines to a parallel plate collector inside the target chamber. The capacitor bank is designed to deliver a peak current of 45 to 50 MA with a 4- to 5-mu s risetime. The Marx modules are designed to be reconfigured to a 480-kV configuration for opening switch development. Predicted performance with a typical load is presented. Descriptions of the major subsystems are also presented. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Parsons, WM (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 0 TC 2 Z9 3 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 673 EP 678 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800094 ER PT B AU Spielman, RB Stygar, WA Seamen, JF Long, F Ives, H Garcia, R Wagoner, T Struve, KW Mostrom, M Smith, I Spence, P Corcoran, P AF Spielman, RB Stygar, WA Seamen, JF Long, F Ives, H Garcia, R Wagoner, T Struve, KW Mostrom, M Smith, I Spence, P Corcoran, P BE Cooperstein, G Vitkovitsky, I TI Pulsed power performance of PBFA Z SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB PBFA Z is a new 60-TW/5-MJ electrical driver located at Sandia National Laboratories. We use PBFA Z to drive z pinches. The pulsed power design of PBFA Z(1) is based on conventional single-pulse Marx generator, water-line pulse-forming technology used on the earlier Saturn(2) and PBFA II3 accelerators. PBFA Z stores 11.4 MJ in its 36 Marx generators, couples 5 MJ in a 60-TW/105-ns pulse to the output water transmission lines, and delivers 3.0 MJ and 50 TW of electrical energy to the z-pinch load. Depending on the initial load inductance and the implosion time, we attain peak currents of 16-20 MA with a rise time of 105 ns. Current is fed to the z-pinch load through self magnetically-insulated transmission lines (MITLs). Peak electric fields in the MITLs exceed 2 MV/cm. The current from the four independent conical-disk MITLs is combined together in a double post-hole vacuum convolute with an efficiency greater than 95%. We achieved x-ray powers of 200 TW and x-ray energies of 1.9 MJ from tungsten wire-array z-pinch loads. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Spielman, RB (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 9 Z9 18 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 709 EP 714 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800098 ER PT B AU Akemoto, M Gold, S Krasnykh, A Koontz, R AF Akemoto, M Gold, S Krasnykh, A Koontz, R BE Cooperstein, G Vitkovitsky, I TI Pulse transformer R & D for NLC klystron pulse modulator SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB We have studied a conventional pulse transformer for the NLC klystron pulse modulator. The transformer has been analyzed using a simplified lumped circuit model. It is found that a fast rise time requires low leakage inductance and low distributed capacitance and can be realized by reducing the number of secondary turns, but it produces larger pulse droop and requires a larger core size. After making a tradeoff among these parameters carefully, a conventional pulse transformer with a rise time of 250ns and a pulse droop of 3.6% has been designed and built. The transmission characteristics and pulse time-response were measured. The data were compared with the model. The agreement with the model was good when the measured values were used in the model simulation. The results of the high voltage tests using a klystron load are also presented. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Akemoto, M (reprint author), Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 724 EP 729 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800100 ER PT B AU Matuska, W Lee, H AF Matuska, W Lee, H BE Cooperstein, G Vitkovitsky, I TI Determining the temperature and density distributions from a z-pinch radiation source SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB High temperature radiation sources exceeding one hundred eV can be produced via z-pinches using currently available pulsed power. The usual approach to compare the z-pinch simulation and experimental data is to convert the radiation output at the source, whose temperature and density distributions are computed from the 2-D MHD code, into simulated data such as a spectrometer reading. This conversion process involves a radiation transfer calculation through the axially symmetric source, assuming local thermodynamic equilibrium (LTE), and folding the radiation that reaches the detector with the frequency-dependent response function. In this paper we propose a different approach by which we can determine the temperature and density distributions of the radiation source directly from the spatially resolved spectral data. This unfolding process is reliable and unambiguous for the ideal case where LTE holds and the source is axially symmetric. In reality, imperfect LTE and axial symmetry will introduce inaccuracies into the unfolded distributions. We use a parameter optimization routine to find the temperature and density distributions that best fit the data. We know from our past experience that the radiation source resulting from the implosion of a thin fail does not exhibit good axial symmetry, However, recent experiments carried out at Sandia National Laboratory using multiple wire arrays were very promising to achieve reasonably good symmetry. For these experiments our method will provide a valuable diagnostic tool. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Matuska, W (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 826 EP 831 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800118 ER PT B AU Lopez, EA Bennett, GA Bartsch, RR Cochrane, JC Griego, JR Hicks, RD Hinckley, WB Hosack, KW Kasik, RJ Marquez, A Parsons, WM Reass, WA Thompson, MC Casper, D AF Lopez, EA Bennett, GA Bartsch, RR Cochrane, JC Griego, JR Hicks, RD Hinckley, WB Hosack, KW Kasik, RJ Marquez, A Parsons, WM Reass, WA Thompson, MC Casper, D BE Cooperstein, G Vitkovitsky, I TI Rail-gap switch modifications and test data for the Atlas capacitor bank SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Atlas is a facility being designed at the Los Alamos National Laboratory (LANL) to perform high energy-density experiments in support of weapons-physics and basic-research programs. The capacitor bank design consists of a 36-MJ array of 240-kV Marx modules. The system is designed to deliver a peak current of 40-50 MA with a 4-5 us risetime. Evaluation, testing and qualification of key components of the Man; module are being conducted. One key element of the Marx module is the low inductance, high-voltage, high-current, high-coulomb transfer spark-gap switch needed for this application, 304 of which will be used in the Atlas capacitor bank. Because of the Man: module configuration, overall system inductance requirements, and the need for a triggered switch, the design team initially selected the Maxwell Technologies rail-gap switch. The switch has been used in other high-voltage, high-current, high-coulomb transfer applications and would meet the Atlas facility requirements with some modifications. Testing of the Maxwell rail-gap switch under expected Atlas conditions is in progress. I;or the Atlas application, the rail-gap switch required some mechanical design modifications, which are discussed. Maxwell provided two modified switches for testing and evaluation. Results of this testing, before and after modifications, and inherent maintenance improvements to meet overall system reliability will be discussed. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Lopez, EA (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 881 EP 886 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800128 ER PT B AU Savage, ME Simpson, WW Sharpe, RA Reynolds, FD AF Savage, ME Simpson, WW Sharpe, RA Reynolds, FD BE Cooperstein, G Vitkovitsky, I TI Switch evaluation test system for the National Ignition Facility SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Flashlamp pumped lasers use pulsed power switches to commute energy stored in capacitor banks to the flashlamps. To lower the total cost of these switches, Sandia National Laboratories has a research program to evaluate large closing switches. The particular application in which we are interested is the National Ignition Facility (NIF), being designed by Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and Sandia National Laboratories. The target value of the energy switched by a single device is 1.6 MJ, from a 6 mF, 24 k V capacitor bank. The peak current is 500 WI. The lifetime of the NIF; facility is 24 thousand shots. There is no switch today proven at these parameters. Several short-lived switches (100's of shots) exist that can handle the voltage and current, but would require maintenance during the facility life. Other type devices, notably ignitrons, have published lifetimes in excess of 20 thousand shots, but at lower currents and shorter pulse widths. The goal of the experiments at Sandia is to test switches with the ill NIF wave shape, and at the correct voltage. The Sandia facility can provide over 500 kA at 24 kV charge voltage. The facility has 6.4 mF total capacitance, arranged in 25 sub-modules. The modular design makes the facility more flexible (for possible testing at lower current) and safer. For pulse shaping (the NIF wave shape is critically damped) there is an inductor and resistor for each of the 25 modules. Rather than one large inductor and resistor, this lowers the current in the pulse shaping components, and raises their value to those more easily attained with lumped inductors and resistors. We will show the design of the facility, and show results from testing conducted thus far. We will also show details of the testing plan for high current switches. C1 Sandia Natl Labs, High Energy Plasma Phys Dept, Albuquerque, NM 87185 USA. RP Savage, ME (reprint author), Sandia Natl Labs, High Energy Plasma Phys Dept, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 6 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 948 EP 953 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800139 ER PT B AU Zutavern, FJ Loubriel, GM Hjalmarson, HP Mar, A Helgeson, WD O'Malley, MW Ruebush, MH Falk, RA AF Zutavern, FJ Loubriel, GM Hjalmarson, HP Mar, A Helgeson, WD O'Malley, MW Ruebush, MH Falk, RA BE Cooperstein, G Vitkovitsky, I TI Properties of high gain GaAs switches for pulsed power applications SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB High gain GaAs photoconductive semiconductor switches (PCSS) are being used in a variety of electrical and optical short pulse applications. The highest power application, which we are developing, is a compact, repetitive, short pulse linear induction accelerator. The array of PCSS, which drive the accelerator, will switch 75 kA and 250 kV in 30 ns long pulses at 50 Hz. The accelerator will produce a 700 kV, 7kA electron beam for industrial and military applications. In the low power regime, these switches are being used to switch 400 A and 5 kV to drive laser diode arrays which produce 100 ps optical pulses. These short optical pulses are for military and commercial applications in optical and electrical range sensing, 3D laser radar, and high speed imaging. Both types of these applications demand a better understanding of the switch properties to increase switch lifetime, reduce jitter, optimize optical triggering, and improve overall switch performance. These applications and experiments on the fundamental behavior of high gain GaAs switches will be discussed. Open shutter, infra-red images and time-resolved Schlieren images of the current filaments, which form during high gain switching, will be presented. Results from optical triggering experiments to produce multiple, diffuse filaments for high current repetitive switching will be described. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Zutavern, FJ (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 959 EP 964 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800141 ER PT B AU Pinnaduwage, LA AF Pinnaduwage, LA BE Cooperstein, G Vitkovitsky, I TI Implications of electron attachment to highly-excited states in pulsed-power discharges SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB We point out the possible implications of electron attachment to highly-excited states of molecules in two pulsed power technologies. One involves the pulsed H-2 discharges used for the generation of H- ion beams for magnetic fusion energy and particle accelerators. The other is the power modulated plasma discharges used for material processing. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Pinnaduwage, LA (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1048 EP 1053 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800157 ER PT B AU Benage, JF Wysocki, FJ Bowers, R Oona, H Broste, W Harper, R Roderick, N AF Benage, JF Wysocki, FJ Bowers, R Oona, H Broste, W Harper, R Roderick, N BE Cooperstein, G Vitkovitsky, I TI Experiments on planar plasma flow switches at Los Alamos SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB We have performed a series of experiments on the Colt facility at Los Alamos to study the performance of plasma flow switches and to understand the important physics issues which affect that performance. These experiments were done in planar geometry on a small machine to allow for better diagnostic access and a higher repetition rare. The Colt facility is a capacitor bank which stores 300 kJ at maximum charge and produced a peak current of 1.1 MA in 2.0 microseconds for these experiments. The diagnostics used for these experiments included an array of b-dot probes, visible framing pictures, visible spectroscopy, and laser interferometry. Characteristics of the switch are determined from spatial and temporal profiles of the magnetic field and the spatial profile and temperature of the switch plasma. Here we present results from experiments for a variety of switch conditions. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Benage, JF (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1233 EP 1238 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800189 ER PT B AU Stygar, WA Spielman, RB Ives, HC Moore, WBS Seamen, JF Sharpe, AW Wagoner, TC Gilliland, TL Broyles, RS Mills, JA Dinwoodie, TA Slopek, JS Struve, KW Reynolds, PG AF Stygar, WA Spielman, RB Ives, HC Moore, WBS Seamen, JF Sharpe, AW Wagoner, TC Gilliland, TL Broyles, RS Mills, JA Dinwoodie, TA Slopek, JS Struve, KW Reynolds, PG BE Cooperstein, G Vitkovitsky, I TI D-dot and B-dot monitors for Z-vacuum-section power-flow measurements SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB New differential D-dot and B-dot monitors were developed for the Z vacuum section. The D-dots measure voltage at the insulator stack. The B-dots measure current at the stack and in the outer magnetically-insulated transmission lines. Each monitor has two outputs chat allow common-mode noise to be cancelled to first order. The differential D-dot has one signal and one noise channel; the differential B-dot has two signal channels with opposite polarities. Each of the two a-dot sensors in the differential B-dot monitor has four 3-mm-diameter loops and is encased in copper to reduce flux penetration. For both types of probes, two 2.2-mm-diameter coaxial cables connect the outputs to a Prodyn balun for common-mode-noise rejection. The cables provide reasonable bandwidth and generate acceptable levels of Compton drive in the bremsstrahlung field of the Z accelerator. A new cavity B-dot is being developed to measure the total Z current 4.3 cm from the axis of the z-pinch load. All of the sensors are calibrated with 2-4% accuracy. The monitor signals are reduced with Earth or Weinschel attenuators, recorded on Tektronix 0.5-ns/sample digitizing oscilloscope, and software cable compensated and integrated. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Stygar, WA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 9 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1258 EP 1263 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800193 ER PT B AU Idzorek, GC Bartlett, RJ AF Idzorek, GC Bartlett, RJ BE Cooperstein, G Vitkovitsky, I TI Silicon photodiode soft x-ray detectors for pulsed power experiments SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Silicon photodiodes offer a number of advantages over conventional photocathode type soft x-ray detectors in pulsed power experiments. These include a nominally flat response, insensitivity to surface contamination, low voltage biasing requirements, sensitivity to law energy photons, excellent detector to detector response reproducibility, and ability to operate in poor vacuum or gas backfilled experiments. Silicon photodiodes available from International Radiation Detectors (IRD), Torrance, California have been characterized for absolute photon response from 1 eV to 10 keV photon energy, time response, and signal saturation levels. Our calibration measurements show factor of ten deviations from the silicon photodiode theoretical nae response due to diode sensitivity outside the center 'sensitive area'. Detector response reproducibility between diodes appears to be better than 5%. Time response measurements show a 10-90% rise time of about 0.1 nanoseconds and a fail time of about 0.5 nanoseconds. C1 Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. RP Idzorek, GC (reprint author), Univ Calif Los Alamos Natl Lab, Div Phys, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1274 EP 1279 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800196 ER PT B AU Petersen, TL Allred, GD Anderson, BG Bartram, DE Garcia, JA AF Petersen, TL Allred, GD Anderson, BG Bartram, DE Garcia, JA BE Cooperstein, G Vitkovitsky, I TI Data acquisition techniques for explosive high current generators SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The Hydrodynamic and X-Ray Physics Group (P-22) at Los Alamos National Laboratory has developed hardware, software, and procedures to work with explosively driven high current generators to obtain time resolved data. Data recording in this physically and electrically harsh environment requires special equipment, techniques, and processes. There are three distinct areas of consideration to record this class of data First is the explosive shot pad area, second is bunker area, and third is the data handling and documentation considerations. It is well within the capability of P-22 to provide 100 to 200 data recording channels and to provide 50 to 100 fiber optic data paths to the recording area The equipment has high frequency bandwidths from 20 MHz to 500 MHz. This work has been conducted in various sites in the United States and Russia The work in Russia presents a particular challenge in the areas of planning for the change in AC power voltage and frequency, different coaxial and connector systems, making sure all components and spare equipment are included in the equipment shipped before the experiment. To avoid ground loops and EMT noise problems fiber optic techniques are used to deliver the data from the shot pad to the recording area in the bunker. Data from electrical B-dot, V-dot, Rogowski, X-ray diodes, Faraday Rotation current measurements, are all part of the diagnostic probes that are routinely recorded by our data acquisition systems. Shielded 50 Ohms coaxial cables deliver the electrical probe signals to an area close to the device, generally about 50 feet,behind a Mast shield Behind the blast shield will be several EMI shielded boxes containing fiber optic transmitters and proper attenuation for the probe signals. There will be different EMI shielded boxes for electrical probes, depending on different electrical potentials on the device. These fiber optic transmitters are battery powered and are allowed to float electrically. The bunker area contains the fiber optic receivers, waveform digitizers, triggering equipment and data acquisition computers. From the shot pad area optical fibers provide the signal path into the bunker and the fiber optic receivers. Where necessary the bunker ground loops are broken with fiber optic trigger hardware and large-scale un-interuptable power supplies (UPS). These units have storage batteries to provide clean AC power to operate the data recording equipment during the experiment The handling of the data and documentation of the data is considered part of the data recording effort. Calibrations of time and amplitude before the event provide post event corrections for the data. The data is stored on the computer and is available for data analysis programs. In addition documentation of the experimental setup is provided for pre-event review and post-event analysis. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87575 USA. RP Petersen, TL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87575 USA. NR 0 TC 0 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1280 EP 1284 PG 5 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800197 ER PT B AU Scudder, DW Hosack, KW Parsons, WM Reass, WA Thompson, MC Wysocki, FJ Creager, J AF Scudder, DW Hosack, KW Parsons, WM Reass, WA Thompson, MC Wysocki, FJ Creager, J BE Cooperstein, G Vitkovitsky, I TI Controls and data acquisition on Atlas SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The control and data acquisition systems for Atlas will use a large degree of decentralization. By distributing control points close to the systems being controlled we expect to simplify the task of isolating electonic systems from the large expected EMI pulses, allow connection of the various parts of the system by high-level fiber-optic networks, allow a simple configuration of the control and data acquisition screen rooms, and simplify the software efforts through the resulting modularization. The Atlas control system must control capacitor charging, machine and diagnostic timing and triggering, marx module diagnostics, vacuum systems, gas handling for railgaps, safety interlocks, and oil handling. Many of these tasks will be performed by industrial-style programmable logic controllers (PLCs). Each of 38 Marx bank maintenance units will have a control and diagnostic package which will monitor both charging and discharging current and railgap trigger timing. An unusual feature of these marx monitoring stations will be the inclusion of high speed digitizers to record each marx module's output waveform, plus nanosecondresolution time interval meters to record the firing time of each railgap. The machine data acquisition system for Atlas will be built around an SQL database, use National Instruments LabVIEW software to control data acquisition instruments and provide links for a variety of experimentalists' data analysis packages. World Wide Web access will provide an interface through which users can monitor experimental data and machine status. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Scudder, DW (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1285 EP 1290 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800198 ER PT B AU Wurden, GA Davis, HA Taylor, A Bowman, D Ballard, E Ney, S Scudder, D Trainor, J AF Wurden, GA Davis, HA Taylor, A Bowman, D Ballard, E Ney, S Scudder, D Trainor, J BE Cooperstein, G Vitkovitsky, I TI Atlas chamber, power flow channel, and diagnostic interface design SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The Atlas pulsed-power machine, presently being designed at Los Alamos, will deliver a pulse of similar to 45 MA, in 4-5 mu sec, with energies of up to 6 MJ (from a bank of 36 MJ maximum) to a load assembly, located in vacuum. Design considerations for the vacuum vessel, power flow channel from the vessel inward, are presented. In contrast to Sandia's PBFA II-Z, where 20 MA currents and 2-2.5 MJ of energy are delivered to (similar to 15 mg) loads in similar to 100 nsec, the Atlas structures will have to be designed for longer timescales and higher energies to drive heavy liners (similar to 70 g). Design issues for the chamber include materials stresses, formation of (and protection from) debris and molten jets, impulse loading, and survivability and ease of replacement of internal structures. For the power flow channel designs, issues are minimizing inductance, preventing movement of conductors during and after firing, damage mitigation, reducing the cost of materials and installation, and electrical insulation. A key issue for damage mitigation is the radius within which total destruction of material objects occurs. Choices of vessel size, insulator materials, cost and ease of manufacturing, and mechanical stability issues are presently in the conceptual design phase. Typical access requirements for diagnostics (including radial and axial X-ray backlighting, flux loops, spectroscopy, interferometry, bolometry, etc.) are provided for in the design. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wurden, GA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1291 EP 1296 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800199 ER PT B AU Fulkerson, ES Norman, DC Booth, R AF Fulkerson, ES Norman, DC Booth, R BE Cooperstein, G Vitkovitsky, I TI Driving Pockels cells using avalanche transistor pulsers SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Fulkerson, ES (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-054, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1341 EP 1346 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800208 ER PT B AU Rose, CR Barlow, DB Redd, DB AF Rose, CR Barlow, DB Redd, DB BE Cooperstein, G Vitkovitsky, I TI Initial test results of the Los Alamos proton-storage-ring bump-magnet system SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB An upgrade program for increasing the stored beam current in the LANSCE Proton Storage is presently under way. Part of the upgrade effort has been to design, specify, and add four bump-magnet/modulator systems to the ring. This paper describes the initial test results of the first bump-magnet/modulator system. The paper begins with an overview of the pulsed-power system including important specifications of the modulator, magnet, cabling, and control system. In the main portion of the paper, waveforms and test data are included showing the accuracy, repeatability, and stability of the magnet-current pulses. These magnet pulses are programmable both in rise and fall time as well as in amplitude. The amplitude can be set between 50 and 300 A, the rise-time is fixed at 1 ms, and the linear fall-time can be varied between 500 mu s and 1500 mu s. Other issues such as loading effects and power dissipation in the magnet-bore beamtube are examined and reported. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rose, CR (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663,MS H808, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1347 EP 1350 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800209 ER PT B AU Clark, DA Anderson, BG Ekdahl, CA Faehl, RJ Goforth, JH Lindemuth, IR Petersen, TL Reinovsky, RE Tabaka, LJ Chernyshev, VK Mokhov, VN Buzin, VN Byrenkov, OM Bujko, AM Vakhruchev, VV Garanin, SF Grinevich, BE Gorbachov, YN Gubkov, EB Demidov, BA Dudoladov, VI Zmushko, VV Kuzyaev, AI Kucherov, AI Lovyagin, BM Matsev, YI Nizovtsev, PN Petrukhin, AA Pishurov, AI Sokolov, SS Solovjov, VP Startsev, AI Yakubov, VB AF Clark, DA Anderson, BG Ekdahl, CA Faehl, RJ Goforth, JH Lindemuth, IR Petersen, TL Reinovsky, RE Tabaka, LJ Chernyshev, VK Mokhov, VN Buzin, VN Byrenkov, OM Bujko, AM Vakhruchev, VV Garanin, SF Grinevich, BE Gorbachov, YN Gubkov, EB Demidov, BA Dudoladov, VI Zmushko, VV Kuzyaev, AI Kucherov, AI Lovyagin, BM Matsev, YI Nizovtsev, PN Petrukhin, AA Pishurov, AI Sokolov, SS Solovjov, VP Startsev, AI Yakubov, VB BE Cooperstein, G Vitkovitsky, I TI High energy imploding liner experiment HEL-1: Experimental results SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Magnetically driven imploding liner systems can be used as a source of shock energy for materials equation of state studies, implosion driven magnetized plasma fusion experiments, and other similar applications. The imploding liner is a cylinder of conducting material through which a current is passed in the longitudinal direction. Interaction of the current with its own magnetic field causes the liner to implode. Sources of electrical energy for imploding liner systems are capacitor banks or explosive pulse power systems seeded by capacitor banks. In August, 1996, a high energy liner experiment (HEL-I) was conducted at the All-Russia Scientific Research Institute (VNIIEF) in Sarov, Russia. A 5 tier I meter diameter explosive disk generator provided electrical energy to drive a 48cm outside diameter, 4 mm thick, aluminum alloy liner having a mass of about I kg onto an II cm diameter diagnostic package. We purpose of the experiment was to measure performance of the explosive pulse power generator and the heavy imploding liner. Electrical performance diagnostics included inductive (B-dot) probes, Faraday Rotation current measurement Rogowski total current measurement and voltage probes. Flux loss and conductor motion diagnostics included current-joint voltage measurements and motion sensing contact pins. Optical and electrical impact pins, inductive (B-dot) probes, manganin pressure probes, and continuously recording resistance probes in the Central Measuring Unit (CMU) and Piezo and manganin pressure probes, optical beam breakers, and inductive probes located in the glide planes were used as liner symmetry and velocity diagnostics. Preliminary analysis of the data indicate that a peak cur rent of more than 100 IMA was attained and the liner velocity was between 6.7 km/sec and 7.5 km/sec. Liner kinetic energy was between 22 MJ and 35 MJ. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Clark, DA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1369 EP 1374 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800213 ER PT B AU Faehl, RJ Sheehey, PT Reinovsky, RE Lindemuth, IR Buyko, AM Chernyshev, VK Garanin, SF Mokhov, VN Yakubov, VB AF Faehl, RJ Sheehey, PT Reinovsky, RE Lindemuth, IR Buyko, AM Chernyshev, VK Garanin, SF Mokhov, VN Yakubov, VB BE Cooperstein, G Vitkovitsky, I TI Modeling and analysis of the high energy liner experiment, HEL-1 SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB A high energy, massive liner experiment, driven by an explosive flux compressor generator, was conducted at VNIIEF firing point, Sarov, on August 22, 1996. We report results of numerical modeling and analysis we have performed on the solid liner dynamics of this 4.0 millimeter thick aluminum liner as it was imploded from an initial inner radius of 236 mm onto a Central Measuring Unit (CMU), radius 55 mm. Both one-and two-dimensional MHD calculations have been performed, with emphasis on studies of Rayleigh-Talylor instability in the presence of strength and on liner/glide plane interactions. One-dimensional MHD calculations using the experimental current profile confirm that a peak generator current of 100-105 MA yields radial liner dynamics which are consistent with both glide plane and CMU impact diagnostics. These calculations indicate that the liner reached velocities of 6.9-7.5 km/s before CMU impact. Kinetic energy of the liner, integrated across its radial cross-section, is between 18-22 MJ. Since the initial goal was to accelerate the liner to at least 20 MJ, these calculations are consistent with overall success. Two-dimensional MHD calculations were employed for more detailed comparisons with the measured data set. The complete data set consisted of over 250 separate probe traces. From these data and from their correlation with the MHD calculations, we can conclude that the liner deviated from simple cylindrical shape during its implosion. Two-dimensional calculations have clarified our understanding of the mechanisms responsible for these deformations. Many calculations with initial outer edge perturbations have been performed to assess the role of Rayleigh-Taylor instability. Perturbation wavelengths between 4-64 mm and amplitudes between 8-200 mu m have been simulated with the experimental current profiles. When strength is omitted short wavelengths are observed to grow to significant levels; material strength stabilizes such modes in the calculations. Wavelengths long compared to the liner thickness grow to large amplitude in either case. Calculations which include the glide planes (electrodes) exhibit less mode growth than quasi-infinite ones. Mass thinning of the liner results in seater acceleration near the glide planes than near the midplane. The overall liner shape which results is strongly bowed, with a smooth ellipsoidal inner surface. C1 Univ Calif Los Alamos Natl Lab, Plasma Applicat Grp, Los Alamos, NM 87545 USA. RP Faehl, RJ (reprint author), Univ Calif Los Alamos Natl Lab, Plasma Applicat Grp, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1375 EP 1380 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800214 ER PT B AU Morgan, DV Platts, D Shlachter, JS Martinez, DL Carpenter, B AF Morgan, DV Platts, D Shlachter, JS Martinez, DL Carpenter, B BE Cooperstein, G Vitkovitsky, I TI Analysis of radial radiography for the liner stability series at Pegasus: PGII-59, PGII-62, and PGII-63 SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Recently, three liner stability experiments were performed at the Pegasus II pulsed power facility to determine the asymmetric variations in the material density of a cylindrical liner during an electro-magnetically driven implosion. The initial campaign consisted of three experiments, designated LS-1, LS-2, and LS-3. LS-1 and LS-2 were driven with a peak current of approximately 4.2 MA, whereas the peak current for LS-3 was approximately 6.4 MA. All three liners initially were 0.4 mm wall aluminum cylinders with a mean radius of 2.38 cm and a height of 2.0 cm. The inner surface of each liner was coated with a thin (18-23 mu m) layer of gold to aid in the determination of the position of the inner surface of the liner. Radial radiography was used to characterize the z-dependent and theta-dependent instabilities that were observed as the liner contracted. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Morgan, DV (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1381 EP 1386 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800215 ER PT B AU Sorenson, DS Carpenter, B King, NSP Morgan, D Obst, AW Platts, D Rodriguez, P Roberts, J Stelts, M Stokes, J Taylor, T Veeser, L Frogget, BC Malone, RM Tunnell, TW Westley, DT Broste, WB Flurer, R AF Sorenson, DS Carpenter, B King, NSP Morgan, D Obst, AW Platts, D Rodriguez, P Roberts, J Stelts, M Stokes, J Taylor, T Veeser, L Frogget, BC Malone, RM Tunnell, TW Westley, DT Broste, WB Flurer, R BE Cooperstein, G Vitkovitsky, I TI Ejecta experiments at the Pegasus Pulsed Power Facility SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB When a shock wave interacts at the surface of a metal sample "ejected matter" (ejecta) can be emitted from the surface at velocities larger than the sample velocity. The mass, size, shape, and velocity of ejecta varies depending on the initial shock conditions and the target's material properties. In order to understand this phenomena, diagnostics have been developed and implemented at the Pegasus Pulsed Power Facility (PPPF) located at Los Alamos National Laboratory (LANL). The facility provides both radial and axial access for making measurements. There exist optical, laser, and X-Ray paths for performing measurements on the target assembly located near the center of the machine. The facility can provide many mega-amps of current which are transported to a 5.0-cm diameter, 2.0-cm high aluminum cylinder. The current and associated magnetic field set up forces which implode the aluminum cylinder radially inward. As the aluminum cylinder reaches the appropriate velocity, it impacts a target cylinder. Due to this impact, a shock wave is set up in the target and eventually interacts at the inner surface of the target cylinder where ejecta are produced. A 1.5-cm diameter collimator cylinder located in the target cylinder is used to control the number of ejecta particles that arrive at the center region where ejecta measurements are made. Two diagnostic techniques for characterizing ejecta, inline Fraunhofer holography and visible shadowgraphy are detailed in this report. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Sorenson, DS (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 0 TC 0 Z9 0 U1 0 U2 4 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1387 EP 1392 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800216 ER PT B AU Wysocki, FJ Chrien, RE Idzorek, G Oona, H Whiteson, DO Kirkpatrick, RC Lindemuth, IR Sheehey, PT AF Wysocki, FJ Chrien, RE Idzorek, G Oona, H Whiteson, DO Kirkpatrick, RC Lindemuth, IR Sheehey, PT BE Cooperstein, G Vitkovitsky, I TI Progress with developing a target for Magnetized Target Fusion SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Magnetized Target Fusion (MTF) is an approach to fusion where a preheated and magnetized plasma is adiabatically compressed to fusion conditions.(1,2) Successful MTF requires a suitable initial target plasma with an embedded magnetic field of at least 5 T in a closed-field-line topology, a density of roughly 10(18) cm(-3), a temperature of at least 50 eV, and must be free of impurities which would raise radiation losses. Target plasma generation experiments are underway at Los Alamos National Laboratory using the Colt facility; a 0.25 MJ, 2-3 mu s rise-time capacitor bank. The goal of these experiments is to demonstrate plasma conditions meeting the minimum requirements for a MTF initial target plasma. In the first experiments, a Z-pinch is produced inside a 2 cm radius by 2 cm high conducting cylindrical metal container using a static gas-fill of hydrogen or deuterium gas in the range of 0.5 to 2 ton: Thus far, the diagnostics include an array of 12 B-dot probes, a framing camera, a gated OMA visible spectrometer, a time-resolved monochrometer, filtered silicon photodiodes, neutron yield, and plasma-density interferometers. These diagnostics show that a plasma is produced in the containment region that lasts roughly 10 to 20 mu s with a maximum plasma density exceeding 10(18) cm(-3). The experimental design and data are presented. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Wysocki, FJ (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1393 EP 1398 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800217 ER PT B AU Sheppard, MG Atchison, WL Anderson, WE Bartlett, RJ Brownell, JH Calahan, KR Ekdahl, CA Erickson, GA Fortgang, CM Fulton, RD Gore, RA Hall, CR Morgan, DV Oona, H Oro, DM Roberts, JP Rodriguez, G Rohlev, LE Sanders, LD Stokes, JL Stone, JB Studebaker, JK Taylor, A Trainor, RJ Winske, D Wright, BL Bartsch, RR Cochrane, JC Coulter, WL AF Sheppard, MG Atchison, WL Anderson, WE Bartlett, RJ Brownell, JH Calahan, KR Ekdahl, CA Erickson, GA Fortgang, CM Fulton, RD Gore, RA Hall, CR Morgan, DV Oona, H Oro, DM Roberts, JP Rodriguez, G Rohlev, LE Sanders, LD Stokes, JL Stone, JB Studebaker, JK Taylor, A Trainor, RJ Winske, D Wright, BL Bartsch, RR Cochrane, JC Coulter, WL CA MST-7 Pegasus BE Cooperstein, G Vitkovitsky, I TI Rayleigh-Taylor Mix experiment on Pegasus SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB The Rayleigh-Taylor Mbe (RTMIX) project will attempt to diagnose and understand the growth of a mixing layer at the interface between an imploding metal liner and a polystyrene foam core in a series of pulsed power experiments on the Pegasus capacitor bank. Understanding the effects of material strength will be an important part of the study. During the initial phase of the implosion, the liner/foam interface is Rayleigh-Taylor (RT) stable; however, as the foam is compressed, it decelerates the liner causing it to bounce and to go RT unstable. In this paper, we report 1D and 2D MHD simulations and preliminary results from the first experiment in the series. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Sheppard, MG (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1399 EP 1404 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800218 ER PT B AU Reinovsky, RE Lindemuth, IR Lopez, EA Goforth, JH Marsh, SP AF Reinovsky, RE Lindemuth, IR Lopez, EA Goforth, JH Marsh, SP BE Cooperstein, G Vitkovitsky, I TI Caballero: A high current flux compressor system for 100MJ solid liner experiments SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Pulse power systems delivering in excess of 100 MJ represent one of the next major challenges to the pulse power community. While a laboratory pulse power system in this energy range is feasible, it represents a very substantial investment of both time and resources. Prudence requires that fundamental proof-of-principle far the contemplated application is established before such massive resources are committed. Explosive pulse power systems using magnetic flux compression provide a direct path to such demonstrations. Furthermore, as energy requirements grow, single use explosive systems may represent the only affordable source of ultra-high energy environments. Currently two flux compressor configurations are under consideration for powering solid liner implosions at currents above 100 MA and at energies above 100 MJ. A simultaneously initiated coaxial flux compressor (Ranchero) is described in a companion paper. A modular, center initiated disk configuration, generally patterned after the DEMG(1) is the other candidate. Either can drive loads directly or can conceptually be connected in parallel with fiat plate transmission lines to increase current delivery. Phenomenological models and conceptual designs for DEMG systems have been previously reported. In this paper we report the results of the experimental test of a first generation disk generator system. individual disk segments have been tested with framing camera diagnostics to evaluate overall performance, dynamics and fabrication failure points. In general no bulk failures were observed in several shots and the critical weld joints maintained their integrity for at least 4 mu s after arrival of the detonation front. Single module pulse power experiments have been conducted at reduced initial current (1.5 - 2.0 MA) with a fixed inductance load of 0.22 nH. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Reinovsky, RE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1448 EP 1453 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800226 ER PT B AU Wilson, MJ Goerz, DA AF Wilson, MJ Goerz, DA BE Cooperstein, G Vitkovitsky, I TI Compact high-voltage structures SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB A basic understanding of the critical issues limiting the compactness of high-voltage systems is required for the next generation of impulse generators. In the process of optimizing the design of a highly reliable so(id-dielectric over-voltage switch, an understanding of the limiting factors found are shown. Results of a 130kV operating switch, having a modest field enhancement of 16% above the average field stress in the switching region, are reported. The resulting high reliability is obtained by reducing the standard deviation of the switch to 6.8%. The total height of the switch is 1-mm. The resulting operating parameters are obtained by controlling field distribution across the entire switch package and field shaping the desired point of switch closure. The disclosed field management technique provides an approach to improve other highly stressed components and structures. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Wilson, MJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808 L-153, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1596 EP 1601 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800253 ER PT B AU Shoup, RW Long, F Martin, TH Spielman, RB Stygar, WA Mostrom, MA Struve, KW Ives, H Corcoran, P Smith, I AF Shoup, RW Long, F Martin, TH Spielman, RB Stygar, WA Mostrom, MA Struve, KW Ives, H Corcoran, P Smith, I BE Cooperstein, G Vitkovitsky, I TI Design validation of the PBFA-Z vacuum insulator stack SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB Sandia has developed PBFA-Z, a 20-MA driver for z-pinch experiments by replacing the water lines, insulator stack, and MITLs on PBFA II with hardware of a new design. The PBFA-Z accelerator was designed to deliver 20 MA to a 15-mg z-pinch load in 100 ns, The accelerator was modeled using circuit codes to determine the time-dependent voltage and current waveforms at the input and output of the water lines, the insulator stack, and the MITLs. The design of the vacuum insulator stack was dictated by the drive voltage, the electric field stress and grading requirements, the water line and MITL interface requirements, and the machine operations and maintenance requirements. The insulator stack consists of four separate modules, each of a different design because of different voltage drive and hardware interface requirements. The shape of the components in each module, i.e., grading rings, insulator rings, flux excluders, anode and cathode conductors, and the design of the water line and MITL interfaces, were optimized by using the electrostatic analysis codes, ELECTRO and JASON. The time-dependent performance of the insulator stacks was evaluated using IVORY, a 2-D PIC code. This paper will describe the insulator stack design, present the results of the ELECTRO and IVORY analyses, and show the results of the stack measurements. C1 Sandia Natl Labs, Dept 9573, Albuquerque, NM 87185 USA. RP Shoup, RW (reprint author), Sandia Natl Labs, Dept 9573, MS-1194, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1608 EP 1613 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800255 ER PT B AU Buckles, R Davis, B Yen, B AF Buckles, R Davis, B Yen, B BE Cooperstein, G Vitkovitsky, I TI A linear hybrid kicker modulator for ETA-II SO 11TH IEEE INTERNATIONAL PULSED POWER CONFERENCE - DIGEST OF TECHNICAL PAPERS, VOLS. 1 & 2 LA English DT Proceedings Paper CT 11th IEEE International Pulsed Power Conference CY JUN 29-JUL 02, 1997 CL BALTIMORE, MD SP USN, Naval Res Lab, IEEE, Nucl & Plasma Sci Soc, Pulsed Powed Sci & Technol Comm AB A new type of pulse modulator is being developed at Livermore that will rapidly split a high current electron beam into two halves, enabling each half to proceed along separate pathways. Each modulator will be capable of applying a +/-10kV, 200A pulse onto a transmission line electrode structure with a rise time less than 10 ns, a pulse repetition frequency greater than 1 MHz, and a maximum pulse duration of 400 ns, The electrode structure, located inside the beam-transport pipe, generates an electromagnetic field that acts on part of the original beam to "kick" it in another direction. The true merit of this high-speed modulator will be its flexibility in pulse duration and shape. The electrodynamics involved in altering the beam's trajectory require the modulator to generate a time-varying pulse that is precisely tailored in amplitude. Consequently, the modulator is driven by an arbitrary waveform generator and must act more as a linear amplifier than as a simple switch. The requirements of high peak power and wide analog bandwidth (about 50 MHz) will be addressed by merging a solid-state driver with an output stage of high-power vacuum tubes. Modulator development and performance data will be presented as will the issues of beam-induced voltage and transit-time isolation that are considered when driving a beam load. C1 LLNL, DOE, Bechtel Nevada, Livermore, CA 94550 USA. RP Buckles, R (reprint author), LLNL, DOE, Bechtel Nevada, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4213-5 PY 1997 BP 1626 EP 1631 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BK95C UT WOS:000073934800258 ER EF