FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Ashton, WB AF Ashton, WB TI Tech intelligence survey finds few are world-class SO RESEARCH-TECHNOLOGY MANAGEMENT LA English DT Editorial Material RP Ashton, WB (reprint author), PACIFIC NW LAB, WASHINGTON, DC USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU INDUSTRIAL RESEARCH INST INC PI WASHINGTON PA 1550 M ST., NW, WASHINGTON, DC 20005 SN 0895-6308 J9 RES TECHNOL MANAGE JI Res.-Technol. Manage. PD MAR-APR PY 1997 VL 40 IS 2 BP 3 EP 5 PG 3 WC Business; Engineering, Industrial; Management SC Business & Economics; Engineering GA WK997 UT WOS:A1997WK99700002 ER PT J AU Yuracko, KL Hadley, SW Perlack, RD Rivera, RG Curlee, TR AF Yuracko, KL Hadley, SW Perlack, RD Rivera, RG Curlee, TR TI Fernald's dilemma: Recycle the radioactively contaminated scrap metal, or bury it? SO RESOURCES CONSERVATION AND RECYCLING LA English DT Article DE life cycle analysis; metals recycle; industrial ecology AB During the past 5 years, a number of US Department of Energy (DOE) funded efforts have demonstrated the technical efficacy of converting various forms of radioactive scrap metal (RSM) into useable products. From the development of accelerator shielding blocks, to the construction of low level waste containers, technology has been applied to this fabrication process in a safe and stakeholder supported manner. The potential health and safety risks to both workers and the public have been addressed, The question remains: do the benefits of fabricating products from RSM outweigh the costs? This paper presents a decision methodology for use within DOE to evaluate the costs and benefits of recycling and reusing some RSM, rather than disposing of this RSM in an approved burial site. The methodology is being applied to a decision on whether the DOE Fernald site should recycle its radioactively contaminated metals. Copyright (C) 1997 Elsevier Science B.V. RP Yuracko, KL (reprint author), OAK RIDGE NATL LAB,1060 COMMERCE PK DR,MS-6480,OAK RIDGE,TN 37830, USA. RI Hadley, Stanton/O-1465-2015 OI Hadley, Stanton/0000-0002-6514-8802 NR 8 TC 1 Z9 1 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-3449 J9 RESOUR CONSERV RECY JI Resour. Conserv. Recycl. PD MAR PY 1997 VL 19 IS 3 BP 187 EP 198 DI 10.1016/S0921-3449(96)01188-3 PG 12 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WG912 UT WOS:A1997WG91200003 ER PT J AU Lee, Y Gough, RA Kunkel, WB Leung, KN Perkins, LT Pickard, DS Sun, L Vujic, J Williams, MD Wutte, D AF Lee, Y Gough, RA Kunkel, WB Leung, KN Perkins, LT Pickard, DS Sun, L Vujic, J Williams, MD Wutte, D TI Ion energy spread and current measurements of the rf-driven multicusp ion source SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Axial energy spread and useful beam current of positive ion beams have been carried out using a radio frequency (rf)-driven multicusp ion source. Operating the source with a 13.56 MHz induction discharge, the axial energy spread is found to be approximately 3.2 eV. The extractable beam current of the rf-driven source is found to be comparable to that of filament-discharge sources. With a 0.6 mm diameter extraction aperture, a positive hydrogen ion beam current density of 80 mA/cm(2) can be obtained at a rf input power of 2.5 kW. The expected source lifetime is much longer than that of filament discharges. (C) 1997 American Institute of Physics. RP Lee, Y (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 9 TC 15 Z9 18 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 MAR PY 1997 VL 68 IS 3 BP 1398 EP 1402 DI 10.1063/1.1147948 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WP247 UT WOS:A1997WP24700010 ER PT J AU TonThat, DM Augustine, MP Pines, A Clarke, J AF TonThat, DM Augustine, MP Pines, A Clarke, J TI Low magnetic field dynamic nuclear polarization using a single-coil two-channel probe SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID TRANSMISSION-LINE; RESONANCE; NITROXIDES; NMR AB We describe the design and construction of a single-coil, two-channel probe for the detection of low-field magnetic resonance using dynamic nuclear polarization (DNP). The high-frequency channel of the probe, which is used to saturate the electron spins, is tuned to the electron Larmor frequency, 75 MHz at 2.7 mT, and matched to 50 Omega. Low-field, H-1 nuclear magnetic resonance (NMR) is detected through the second, low-frequency channel at frequencies <1 MHz. The performance of the probe was tested by measuring the DNP of protons in a manganese (II) chloride solution at 2.7 mT. At the proton NMR frequency of 120 kHz, the signal amplitude was enhanced over the value without DNP by a factor of about 200. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,DEPT CHEM,BERKELEY,CA 94720. RP TonThat, DM (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 29 TC 6 Z9 7 U1 0 U2 6 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 MAR PY 1997 VL 68 IS 3 BP 1527 EP 1531 DI 10.1063/1.1147641 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WP247 UT WOS:A1997WP24700033 ER PT J AU Mosher, JC Flynn, ER Quinn, A Weir, A Shahani, U Bain, RJP Maas, P Donaldson, GB AF Mosher, JC Flynn, ER Quinn, A Weir, A Shahani, U Bain, RJP Maas, P Donaldson, GB TI Fetal magnetocardiography: Methods for rapid data reduction SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB Fetal magnetocardigraphy (fMCG) provides a unique method for noninvasive observations of the fetal heart. Electrical currents generated by excitable tissues within the fetal heart yield measurable external magnetic fields, Measurements are performed with superconducting quantum interference devices inductively coupled to magnetometer or gradiometer coils, and the resulting signals are converted to digital form in the data acquisition system. The measured fields are usually contaminated by fetal and maternal movements (usually respiration), other physiological fields such as skeletal muscle contraction, the maternal cardiac signal, and environmental electromagnetic fields. Sensitivity to relatively distant sources, both physiological and environmental, is substantially reduced by the use of magnetic gradiometers. Other contaminants may be removed by proper signal conditioning which may be automatically applied using ''black box'' algorithms that are transparent to the user and highly efficient. These procedures can rapidly reduce the complex signal plus noise waveforms to the desired fMCG with minimal operator interference. (C) 1997 American Institute of Physics. C1 SO GEN HOSP,INST NEUROL SCI,GLASGOW G51 4TF,LANARK,SCOTLAND. UNIV STRATHCLYDE,DEPT PHYS & APPL PHYS,GLASGOW,LANARK,SCOTLAND. RP Mosher, JC (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 10 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 MAR PY 1997 VL 68 IS 3 BP 1587 EP 1595 DI 10.1063/1.1147930 PG 9 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA WP247 UT WOS:A1997WP24700044 ER PT J AU MacDonald, MJ Muller, SJ AF MacDonald, MJ Muller, SJ TI Shear rheology of polymer solutions near the critical condition for elastic instability SO RHEOLOGICA ACTA LA English DT Article DE polymer migration; anomalous rheology; Boger fluid; normal stress; elastic instability ID ROTATING PARALLEL DISKS; CONE-AND-PLATE; SPIRAL INSTABILITIES; PHASE-SEPARATION; BOGER FLUIDS; FLOW; LIQUIDS; SPHERES AB The use of constant viscosity, highly elastic polymer solutions, so called Boger fluids, has been remarkably successful in elucidating the behavior of polymeric materials under flowing conditions. However, the behavior of these fluids is still complicated by many different physical processes occurring within a narrow window of observation time and applied shear rate. In this study, we investigate the long-time shear behavior of an ideal Boger fluid: a well characterized, athermal, dilute, binary solution of high molecular weight polystyrene in oligomeric polystyrene. Rheological measurements show that under an applied steady shear flow, this family of polymer solutions undergoes a transient decay of normal stresses on a timescale much longer than the polymer molecule's relaxation time. Rheological and flow visualization results demonstrate that the observed phenomenon is not caused by polymer degradation, phase separation, viscous heating, or secondary flows from elastic instabilities. Although the timescale is much shorter than that associated with polymer migration in the same solutions (MacDonald and Muller, 1996), the appearance of this phenomenon only at the rates where migration has been observed suggests that it may be a prerequisite for observing migration. In addition, we note that through sufficient preshearing of the sample, the normal stress decrease suppresses the elastic instability. These results show that there is considerable uncertainty in choosing the appropriate measure of the fluid relaxation time for consistently modeling the critical condition for the elastic instability, the decay of normal stresses, and the migration of polymer species. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 30 TC 8 Z9 8 U1 1 U2 5 PU DR DIETRICH STEINKOPFF VERLAG PI DARMSTADT PA PLATZ DER DEUTSCHEN EINHEIT 25, D-64293 DARMSTADT, GERMANY SN 0035-4511 J9 RHEOL ACTA JI Rheol. Acta PD MAR-APR PY 1997 VL 36 IS 2 BP 97 EP 109 DI 10.1007/BF00366816 PG 13 WC Mechanics SC Mechanics GA WX412 UT WOS:A1997WX41200001 ER PT J AU Nordahl, TE Kusubov, N Carter, C Kraft, L Salamat, S Baldo, J Robertson, L AF Nordahl, TE Kusubov, N Carter, C Kraft, L Salamat, S Baldo, J Robertson, L TI Regional cerebral glucose metabolic differences via the PET-600 in paranoid schizophrenics performing a Stroop task SO SCHIZOPHRENIA RESEARCH LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,BERKELEY,CA 94720. UNIV CALIF DAVIS,MED CTR,DEPT PSYCHIAT,SACRAMENTO,CA 95817. NAPA STATE HOSP,BIOL RES & TREATMENT CTR,NAPA,CA 94558. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0920-9964 J9 SCHIZOPHR RES JI Schizophr. Res. PD MAR PY 1997 VL 24 IS 1-2 BP 170 EP 170 DI 10.1016/S0920-9964(97)82489-9 PG 1 WC Psychiatry SC Psychiatry GA WP196 UT WOS:A1997WP19600482 ER PT J AU Fukumoto, K Chung, HM Gazda, J Smith, DL Matsui, H AF Fukumoto, K Chung, HM Gazda, J Smith, DL Matsui, H TI Helium behavior in vanadium-based alloys irradiated in the dynamic helium charging experiments SO SCIENCE REPORTS OF THE RESEARCH INSTITUTES TOHOKU UNIVERSITY SERIES A-PHYSICS CHEMISTRY AND METALLURGY LA English DT Article AB Helium effect of neutron irradiated vanadium alloys. containing titanium, has been studied using Dynamic Helium Charging Experiment (DHCE) in FFTF. Cavity formation was observed only in pure vanadium irradiated at 430 to 600 degrees C and in V-5Ti irradiated at 600 degrees C. No apparent cavity formation was obtained in V-3Ti-1Si and V-4Cr-4Ti. The precipitation of titanium oxide in V-5Ti, V-3Ti-1Si and V-4Cr-4Ti occurred in all irradiation conditions in this study and the precipitates of Ti5Si3 only appeared in V-3Ti-1Si irradiated at 600 degrees C up to 15 dpa with helium generation rate of 4 appmHe/dpa. It is suggested that titanium oxide plays an important role for suppression of cavity formation and swelling from early stage of irradiation. Detail characterization of precipitates and He effect for neutron damages in vanadium alloys are discussed here. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Fukumoto, K (reprint author), TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. NR 12 TC 3 Z9 3 U1 0 U2 0 PU INST MATERIALS RESEARCH LIBRARY PI SENDAI PA TOHOKU UNIV KATAHIRA 2-1-1, SENDAI 980, JAPAN SN 0040-8808 J9 SCI REP RES TOHOKU A JI Sci. Rep. Res. Inst. Tohoku Univ. Ser. A-Phys. Chem. Metall. PD MAR PY 1997 VL 45 IS 1 BP 149 EP 155 PG 7 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XR931 UT WOS:A1997XR93100030 ER PT J AU Muralidharan, G Richardson, JW Epperson, JE Chen, H AF Muralidharan, G Richardson, JW Epperson, JE Chen, H TI Lattice parameters and compositions of gamma and gamma' during coarsening in the Ni-Al-Si system: A neutron powder diffraction study SO SCRIPTA MATERIALIA LA English DT Article C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. UNIV ILLINOIS,DEPT MAT SCI & ENGN,URBANA,IL 61801. RP Muralidharan, G (reprint author), ARGONNE NATL LAB,IPNS,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Muralidharan, Govindarajan/J-6155-2015 NR 16 TC 5 Z9 5 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 MAR 1 PY 1997 VL 36 IS 5 BP 543 EP 549 DI 10.1016/S1359-6462(96)00419-8 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WK163 UT WOS:A1997WK16300008 ER PT J AU Roehnelt, R Kassner, ME Kennedy, TC Rosen, RS AF Roehnelt, R Kassner, ME Kennedy, TC Rosen, RS TI Elastic incompatibility stresses across planar and nonplanar grain boundaries applied to ductile fracture criteria under high triaxial stress SO SCRIPTA MATERIALIA LA English DT Article C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Roehnelt, R (reprint author), OREGON STATE UNIV,DEPT MECH ENGN,CORVALLIS,OR 97331, USA. NR 9 TC 2 Z9 2 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 MAR 1 PY 1997 VL 36 IS 5 BP 605 EP 610 DI 10.1016/S1359-6462(96)00428-9 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WK163 UT WOS:A1997WK16300017 ER PT J AU Dendy, JE AF Dendy, JE TI Revenge of the semicoarsening frequency decomposition multigrid method SO SIAM JOURNAL ON SCIENTIFIC COMPUTING LA English DT Article DE multigrid; parallel computation; global ocean modeling ID GRID METHOD AB The frequency decomposition multigrid method was previously considered and modified so as to obtain robustness for problems with discontinuous coefficients while retaining robustness for problems with anisotropic coefficients. The application of this modified method to a problem arising in global ocean modeling was also considered. For this problem it was shown that the discretization employed gives rise to an operator for which point relaxation is not robust. In fact, alternating line relaxation is required for robustness, negating the main advantage of the frequency decomposition method: robustness for anisotropic operators using only point relaxation. In this paper a semicoarsening variant, which requires line relaxation in one direction only, is considered. and it is shown that this variant works well for the global ocean modeling problem. RP Dendy, JE (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 20 TC 1 Z9 1 U1 0 U2 0 PU SIAM PUBLICATIONS PI PHILADELPHIA PA 3600 UNIV CITY SCIENCE CENTER, PHILADELPHIA, PA 19104-2688 SN 1064-8275 J9 SIAM J SCI COMPUT JI SIAM J. Sci. Comput. PD MAR PY 1997 VL 18 IS 2 BP 430 EP 440 DI 10.1137/S1064827594278095 PG 11 WC Mathematics, Applied SC Mathematics GA WJ897 UT WOS:A1997WJ89700005 ER PT J AU Elless, MP Timpson, ME Lee, SY AF Elless, MP Timpson, ME Lee, SY TI Concentration of uranium particulates from soils using a novel density-separation technique SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article AB Soils contaminated with heavy metals or radionuclides at concentrations above regulatory limits pose an environmental and human health risk. Whereas regulatory limits are only concerned with the ''extent'' of the contamination, knowledge of the ''nature'' of the contamination (e.g., oxidation state and mineralogy of the contaminant, particulate vs. adsorbed form, etc.) is necessary for developing optimal treatment strategies. Mineralogical identification of the contaminants provides important information concerning the nature of the contamination because once the mineral form is known, its properties can then be determined from geochemical data. To this end, a new density-fractionation technique called the Magstream density separator was used to concentrate U particulates from U-contaminated soils at a former U.S. Department of Energy U-metal production facility. Results from neutron-activation analysis of each density fraction showed that the U had been concentrated (up to Ii-fold) in the heavier fractions. Mineralogical analyses of the density fractions of these soils using x-ray diffraction, scanning-electron microscopy, and an electron microprobe showed the predominance of an autunite [Ca(UO2)(2)(PO4)(2).10-12H(2)O]- like mineral with lesser amounts of uraninite (UO2) and coffinite (USiO4) as the U-bearing minerals in these soils. The presence of reduced forms of U in these soils suggests that the optimal remediation strategy requires treatment with an oxidizing agent in addition to a carbonate-based leachant to solubilize and remove U from these soils. C1 NO ARIZONA UNIV,QUATERNARY STUDIES PROGRAM,FLAGSTAFF,AZ 86011. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP Elless, MP (reprint author), UNIV TENNESSEE,DEPT PLANT & SOIL SCI,KNOXVILLE,TN 37901, USA. NR 17 TC 6 Z9 6 U1 0 U2 0 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAR-APR PY 1997 VL 61 IS 2 BP 626 EP 631 PG 6 WC Soil Science SC Agriculture GA WW564 UT WOS:A1997WW56400036 ER PT J AU Kaplan, DI Bertsch, PM Adriano, DC AF Kaplan, DI Bertsch, PM Adriano, DC TI Mineralogical and physicochemical differences between mobile and nonmobile colloidal phases in reconstructed pedons SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID SOIL CLAYS; INFILTRATION; GROUNDWATER; WATER AB Ultisols can be highly dispersive and therefore a potential source for mobile colloids to underlying aquifers. In this study, mobile colloids were collected after a rain from 13.5-m(3) lysimeters containing reconstructed pedons of two Ultisols. The mobile colloids were enriched with kaolinite, Fe oxides, and gibbsite and were more dilute in quartz and hydroxy-interlayered vermiculite (HIV) relative to the total clay fractions of the originating pedons. The colloids were <1000 Nn in diameter and had a bimodal size distribution: the larger colloids (approximate to 760 nm) consisted primarily of quartz and HIV; the much more abundant smaller colloids (approximate to 230 nm) consisted primarily of Fe oxides, kaolinite, and gibbsite. The colloids also had exceptionally high negative surface charges that probably originated from organic coatings (10 g kg(-1)). These organic coatings indicate that the majority of the colloids originated from the surface horizon, the only horizons with measurable amounts of organic C. Soil minerals most likely to enter the mobile phase (Fe oxides, gibbsite, and kaolinite) were readily dispersible and in the <200-nm fraction. The HIV in the reconstructed pedons was readily dispersible but because of its relatively large size (>200 nm), it was removed from the mobile phase during transport, presumably via a straining mechanism. Quartz was neither readily dispersible nor abundant in the <200-nm fraction and, therefore, was not prevalent in the mobile phase. The ability of Ultisols to release colloids that can readily move through a pedon may make these soils and the underlying aquifers especially susceptible to colloid-facilitated transport of contaminants. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. RP Kaplan, DI (reprint author), PACIFIC NW LAB, TRANSPORT GEOCHEM GRP, MSIN K6-81, POB 999, RICHLAND, WA 99352 USA. NR 39 TC 55 Z9 57 U1 1 U2 9 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAR-APR PY 1997 VL 61 IS 2 BP 641 EP 649 PG 9 WC Soil Science SC Agriculture GA WW564 UT WOS:A1997WW56400038 ER PT J AU Bechinger, C Burdis, MS Zhang, JG AF Bechinger, C Burdis, MS Zhang, JG TI Comparison between electrochromic and photochromic coloration efficiency of tungsten oxide thin films SO SOLID STATE COMMUNICATIONS LA English DT Article DE thin films; optical properties; light absorption and reflection ID AMORPHOUS WO3; ABSORPTION; DYNAMICS; SPECTRA; OXYGEN AB We investigated the photochromic (PC) and electrochromic (EC) behavior of sputtered tungsten oxide (WO3-y) films with different oxygen deficiency y. It was found that both the PC and EC coloration efficiency increase with increasing oxygen deficiency in tungsten oxide. For PC efficiency, this behavior is consistent with the model of photochromism developed recently. A recently developed model based on the small polaron transition between W5+ and W4+ states has been used to explain the dependence of EC coloring efficiency on the oxygen deficiency in tungsten oxide films. This new mechanism also revealed a close relationship between PC and EC. (C) 1997 Published by Elsevier Science Ltd. C1 UNIV KONSTANZ, D-78434 CONSTANCE, GERMANY. PILKINGTON TECH MANAGEMENT LTD, ORMSKIRK L40 5UF, LANCS, ENGLAND. NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. NR 23 TC 102 Z9 106 U1 4 U2 27 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD MAR PY 1997 VL 101 IS 10 BP 753 EP 756 DI 10.1016/S0038-1098(96)00703-X PG 4 WC Physics, Condensed Matter SC Physics GA WJ701 UT WOS:A1997WJ70100007 ER PT J AU Yacoby, Y Heald, SM Stern, EA AF Yacoby, Y Heald, SM Stern, EA TI Local oxygen octahedra rotations in Ba1-xKxBiO3 and BaBiO3 SO SOLID STATE COMMUNICATIONS LA English DT Article DE superconductors; high-T-c superconductors; EXAFS; order-disorder effects ID X-RAY-ABSORPTION; FERROELECTRIC PHASE-TRANSITION; FINE-STRUCTURE; CURVED-WAVE; SUPERCONDUCTIVITY; SYSTEM; IONS; PB AB We report XAFS investigations of BaBiO3 and Ba0.6K0.4BiO3 in the temperature range from 10 K to 300 K extending out to fourth nearest neighbours. The results show that in both systems the local structure differs substantially from the average structure determined by neutron diffraction measurements. At temperatures up to at least T = 80 K the local oxygen octahedra rotations in BaBiO3 have in addition to the [1 1 0] component a disordered rotation component about the [0 0 1] axis. To within the experimental accuracy the local rotation components about the [10 0], [0 1 0] and [0 0 1] axes are equal. The results in superconducting Ba0.6K0.4BiO3, are consistent with oxygen octahedra rotations either around [1 1 1] or [1 1 0] type axes. If the rotation is assumed to be about [1 1 1] type axes, the rotation angles are 4.5 degrees up to at least T = 220 K. This local rotation exists in spite of the fact that the crystal is on the average cubic at all temperatures. A theoretical study of the effect of these random rotations on the superconducting properties of Ba1-xKxBiO3 may be of interest. (C) 1997 Published by Elsevier Science Ltd. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. RP Yacoby, Y (reprint author), HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. NR 26 TC 26 Z9 26 U1 1 U2 13 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 MAR PY 1997 VL 101 IS 11 BP 801 EP 806 DI 10.1016/S0038-1098(96)00698-9 PG 6 WC Physics, Condensed Matter SC Physics GA WL299 UT WOS:A1997WL29900004 ER PT J AU Fuhrer, MS Ino, K Oka, K Nishihara, Y Zettl, A AF Fuhrer, MS Ino, K Oka, K Nishihara, Y Zettl, A TI Observation of Josephson vortex lattice melting in a highly anisotropic superconductor SO SOLID STATE COMMUNICATIONS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; KOSTERLITZ-THOULESS TRANSITION; LAYERED SUPERCONDUCTOR; RESISTIVE TRANSITION; PHASE-TRANSITIONS; MAGNETIC-FIELD; FLUX LATTICE; C-AXIS; BI2SR2CACU2O8; STATE AB The Josephson vortex lattice state of the highly anisotropic high-T-c superconductor Bi2Sr2CaCu2O8 has been probed by measurements of the out-of-plane (c-axis) resistivity as a function of temperature, current density, magnetic field strength H and magnetic field orientation angle theta. Anomalous dissipation is observed below a critical temperature identified. as the melting transition of the Josephson vortex lattice. The critical T-H and T-theta phase boundaries are determined. The melting transition is interpreted as a Kosterlitz-Thouless depairing of interlayer vortex/anti-vortex pairs. The same model accounts well for unusual in-plane dissipation observed previously in Bi2Sr2CaCu2O8. (C) 1997 Elsevier Science Ltd. C1 LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. ELECTROTECH LAB, TSUKUBA, IBARAKI 305, JAPAN. RP Fuhrer, MS (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. RI Fuhrer, Michael/E-7634-2010; Zettl, Alex/O-4925-2016 OI Fuhrer, Michael/0000-0001-6183-2773; Zettl, Alex/0000-0001-6330-136X NR 28 TC 13 Z9 13 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 MAR PY 1997 VL 101 IS 11 BP 841 EP 845 DI 10.1016/S0038-1098(96)00681-3 PG 5 WC Physics, Condensed Matter SC Physics GA WL299 UT WOS:A1997WL29900012 ER PT J AU Wang, SH Xu, Z Baltisberger, JH Bull, LM Stebbins, JF Pines, A AF Wang, SH Xu, Z Baltisberger, JH Bull, LM Stebbins, JF Pines, A TI Multiple-quantum magic-angle spinning and dynamic-angle spinning NMR spectroscopy of quadrupolar nuclei SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE chemical shift anisotropy; dynamic-angle spinning; multiple-quantum magic-angle spinning; quadrupolar nuclei; tensor orientation ID RESOLUTION O-17 NMR; SOLID-STATE NMR; MAGNETIC-RESONANCE; RUBIDIUM SALTS; DOUBLE-ROTOR; MAS-NMR; ORIENTATION; SPECTRA; AL-27; RB-87 AB Several aspects of the Multiple-Quantum Magic-Angle Spinning (MQMAS) technique (L, Frydman and J,S, Harwood, J, Am, Chem, Sec., 117 (1995) 5367) are compared with Dynamic-Angle Spinning (DAS), Examples of MQMAS spectra are shown for I = 3/2 nuclei with C-Q up to 3.6 MHz, and for: Al-27 (I = 5/2) with C-Q up to 10 MHz. The MQMAS linewidth is largely independent of the magnitude of the homonuclear dipolar interaction, while the spinning sideband manifold is similar to that observed in DAS experiments, MQMAS is technically simple and routinely useful for studying nuclei with short spin-lattice relaxation times, but care must be taken in its use for quantitative studies as the excitation of the triple-quantum coherence is not uniform, In this regard, MQMAS is most useful for samples with small quadrupolar coupling constants, In the specific case of O-17, DAS would give spectra with excellent resolution in comparison to MQMAS, The different advantages of DAS and MQMAS make them useful complementary techniques in many cases, Two additional methods are also presented for extracting the chemical shift anisotropy (CSA) directly for quadrupolar nuclei using the multiple-quantum scheme, (C) 1997 Elsevier Science B,V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. STANFORD UNIV,DEPT GEOG & ENVIRONM SCI,STANFORD,CA 94305. BEREA COLL,DEPT CHEM,BEREA,KY 40404. UNIV CALIF SANTA BARBARA,MAT RES LAB,SANTA BARBARA,CA 93106. NR 40 TC 62 Z9 64 U1 2 U2 16 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 MAR PY 1997 VL 8 IS 1 BP 1 EP 16 DI 10.1016/S0926-2040(96)01277-5 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA WY629 UT WOS:A1997WY62900001 PM 9178419 ER PT J AU Barkigia, KM Melamed, D Sweet, RM Smith, KM Fajer, J AF Barkigia, KM Melamed, D Sweet, RM Smith, KM Fajer, J TI Self-assembled zinc pheoporphyrin dimers. Models for the supramolecular antenna complexes of green photosynthetic bacteria? SO SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY LA English DT Article DE Zn pheoporphyrin d dimer; crystal structure; bacteriochlorophyll d aggregation model ID BACTERIOCHLOROPHYLL-C; RESOLUTION; PROTEIN; ORGANIZATION; CHLOROPHYLL; PORPHYRINS AB The molecular structure of the zinc porphyrin analog of methyl-8,12-diethylbacteriopheophorbide d has been determined by X-ray diffraction. The crystallographic study was undertaken to provide structural foundations for the several models proposed for the supramolecular organization of bacteriochlorophyll (BChl) c, d and e antenna chromophores in vivo and in vitro. Surprisingly, the Zn porphyrins form hydrogen-bonded dimers with extended pi-pi interactions without the expected ligation of the Zn by the 3-(1-hydroxyethyl) group that distinguishes the BChls c, d and e from all other photosynthetic (bacterio) chlorophylls. The crystallographic results provide the first structural benchmarks for this class of metalloporphyrin derivatives and set structural boundaries for other modes of aggregation considered for the chromophores in vitro and in vivo. (C) 1997 Elsevier Science B.V. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. RI Smith, Kevin/G-1453-2011 OI Smith, Kevin/0000-0002-6736-4779 NR 27 TC 9 Z9 9 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1386-1425 J9 SPECTROCHIM ACTA A JI Spectroc. Acta Pt. A-Molec. Biomolec. Spectr. PD MAR PY 1997 VL 53 IS 3 BP 463 EP 469 DI 10.1016/S1386-1425(96)01813-6 PG 7 WC Spectroscopy SC Spectroscopy GA WY413 UT WOS:A1997WY41300018 ER PT J AU Bar, G Rubin, S Martin, T Taylor, TN Swanson, BI Zawodzinski, TA Chow, JT Ferraris, JP AF Bar, G Rubin, S Martin, T Taylor, TN Swanson, BI Zawodzinski, TA Chow, JT Ferraris, JP TI The influence of contamination on compositional imaging of self-assembled monolayers by scanning force microscopy SO SUPRAMOLECULAR SCIENCE LA English DT Article; Proceedings Paper CT Symposium on Self-Assembly and Materials Research at the Meeting of the Materials-Research-Society CY DEC, 1995 CL BOSTON, MA SP Mat Res Soc, USN, Off Naval Res, Elsevier DE self-assembled monolayers; scanning force microscopy; chemical force microscopy; microcontact printing; XPS ID THIN-FILMS; FRICTION; SURFACE; GOLD; DIMENSIONS; FEATURES AB We prepared patterned self-assembled monolayers (SAMs) consisting of hexadecanethiol (16AT) and ferrocenyldodecanethiol (12FAT). The samples were characterized by scanning force microscopy (SFM), X-ray photoelectron spectroscopy (XPS), electrochemistry and contact angle measurements. Lateral force mode (LFM) of SFM shows image contrast even between surface regions of quite similar hydrophobicity. The 12FAT regions undergo irreversible chemical changes and become electrochemically inactive upon long exposure to the laboratory atmosphere. These chemical changes can be monitored by LFM, XPS, contact angle and electrochemistry. The LFM images of the exposed and contaminated samples show a reversed frictional contrast relative to the LFM images of the fresh samples and to the LFM images of the exposed but ethanol-rinsed sample. XPS and SFM data show that the 12FAT regions show more contamination than the 16AT regions. Based on these observations, the mechanism of the LFM image contrast is discussed and other driving forces, arising not only from differences in hydrophobicity but also from basic material properties such as elasticity, packing and contamination, are suggested. (C) 1997 Elsevier Science Ltd. All rights reserved. C1 Univ Freiburg, Freiburger Mat Forschungszentrum, D-79104 Freiburg, Germany. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Texas, Dept Chem, Richardson, TX 75083 USA. RP Bar, G (reprint author), Univ Freiburg, Freiburger Mat Forschungszentrum, Stefan Meier Str 21, D-79104 Freiburg, Germany. NR 26 TC 4 Z9 4 U1 0 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0968-5677 J9 SUPRAMOL SCI JI Supramol. Sci. PD MAR-JUN PY 1997 VL 4 IS 1-2 BP 11 EP 19 DI 10.1016/S0968-5677(96)00052-1 PG 9 WC Chemistry, Multidisciplinary; Materials Science, Multidisciplinary; Multidisciplinary Sciences SC Chemistry; Materials Science; Science & Technology - Other Topics GA YP310 UT WOS:000071264100003 ER PT J AU Okada, M Baddorf, AP Zehner, DM AF Okada, M Baddorf, AP Zehner, DM TI LEED and HREELS investigation of the hydrogen-covered Mo(110) surface SO SURFACE SCIENCE LA English DT Article DE chemisorption; electron energy loss spectroscopy; hydrogen; low energy electron diffraction; low index single crystal surfaces; molybdenum; surface relaxation and reconstruction ID PACKED METAL-SURFACES; W(110) SURFACE; ADSORPTION; RECONSTRUCTION; SCATTERING AB The adsorption of hydrogen on the Mo(110) surface has been investigated by both low-energy electron diffraction (LEED) and high-resolution electron energy loss spectroscopy (HREELS). Results fall into three regimes. For low coverages, the LEED pattern observed remains (1 x 1 ), similar to the clean surface. At hydrogen coverages near 0.5 MI, a substrate reconstruction alters the observed pattern to (2 x 2). For higher coverages, fractional-order diffraction beams are extinguished, leaving a (1 x 1) pattern. Two vibrational peaks are observed in HREELS spectra for both low- and high-coverage regimes at loss energies of 88 and 1.36 meV, and at 99 and 152 meV, respectively. A quasi-trigonal adsorption site is consistent with the vibrational energies and diffraction patterns observed at low and saturation coverages. At intermediate coverages, a vibrational peak with differing symmetry indicates the occupation of a long bridge-site during the transition from (2 x 2) to the hydrogen-saturated (1 x I). No evidence is found for the hydrogen ''liquid'' phase reported by Balden et al. [Phys. Rev. Lett. 73 (1994) 854] for H/W(110); consequently this phase is not responsible for the giant phonon anomalies observed in both systems. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. RI Baddorf, Arthur/I-1308-2016 OI Baddorf, Arthur/0000-0001-7023-2382 NR 34 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1997 VL 373 IS 2-3 BP 145 EP 152 DI 10.1016/S0039-6028(96)01168-5 PG 8 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WL521 UT WOS:A1997WL52100002 ER PT J AU Liang, Y Baer, DR AF Liang, Y Baer, DR TI Anisotropic dissolution at the CaCO3(10(1)over-bar4)-water interface SO SURFACE SCIENCE LA English DT Article DE atomic force microscopy; calcium carbonate; dissolution; interface; kinetics; surface ID ATOMIC-FORCE MICROSCOPY; CALCITE DISSOLUTION; SURFACE-DIFFUSION; CRYSTAL-GROWTH; KINETICS; EPITAXY; SI(001); STEP AB On the basis of the framework of the terrace-ledge-kink model of dissolution, the site-specific dissolution kinetics at the CaCO3(10(1) over bar 4)-water interface have been investigated using atomic force microscopy. The experiment was carried out in a solution cell where the ''real-time'' dissolution kinetics were examined under different flow and temperature conditions. Results show that dissolution proceeds via the creation of pits and the retreat of steps on the surface. In the surface-reaction controlled regime, retreat of steps was found to be anisotropic with two different velocities. From the temperature dependence of the two step velocities, the effective activation energies of dissolution associated with different kink sites were obtained. The study not only provides valuable information on the relationship between the atomic and the site-specific reactivity of the surfaces, but also quantitatively demonstrates the morphological variation of the CaCO3(10(1) over bar 4) surface resulting from dissolution. RP Liang, Y (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 33 TC 95 Z9 95 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1997 VL 373 IS 2-3 BP 275 EP 287 DI 10.1016/S0039-6028(96)01155-7 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WL521 UT WOS:A1997WL52100012 ER PT J AU McCoy, JM LaFemina, JP AF McCoy, JM LaFemina, JP TI Kinetic Monte Carlo investigation of pit formation at the CaCO3(10(1)over-bar4) surface-water interface SO SURFACE SCIENCE LA English DT Article DE atomistic dynamics; calcite; water; computer simulations; mineral-water interfaces; models of surface kinetics; surface chemical reaction; surface structure; morphology; roughness and topography ID ATOMIC-FORCE MICROSCOPY; EPITAXIAL-GROWTH; MBE GROWTH; CALCITE GROWTH; SIMULATION; DISSOLUTION; MORPHOLOGY; AFM AB On the basis of quantitative information derived from atomic-force microscopy (AFM) studies of shallow pit formation at-the CaCO3(10(1) over bar 4) surface-water interface in the surface-reaction regime, we have developed a kinetic Monte Carlo (KMC) model which reproduces quantitatively the experimental behaviour of the time-evolution of the pits. This allows the rates of all the important elementary atomistic processes involved in the dissolution to be obtained, rates not readily obtainable directly from AFM data. The KMC model also provides important insight into the evolution of very small pits, which in principle can be resolved using AFM, but which in practice are very difficult to observe because of the low probability of their occurrence in the microscope scan area. The KMC simulations show that the growing pits exhibit two different growth regimes, in agreement with the predictions of a simple terrace-ledge-kink (TLK) model. For very small pits the linear pit size increases exponentially with time and the pit edges accelerate double-kink self-annihilation regime). Having attained a certain pit size (similar to 25 nm for a temperature of 300 K), thereafter the pit sizes increase linearly with time, the pit edges maintaining a constant velocity (kink-kink annihilation regime). A comparison of the quantitative predictions of the TLK model with KMC simulations shows that, in spite of its simplicity, the TLK model provides a satisfactory semiquantitative description of the pit evolution. The KMC model presented provides the starting point for the development of a more comprehensive model of the calcite-water interface which will include the effects of adsorbates and other variations in interface conditions. RP PACIFIC NW LAB, ENVIRONMENTAL MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. NR 28 TC 46 Z9 46 U1 6 U2 20 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 EI 1879-2758 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1997 VL 373 IS 2-3 BP 288 EP 299 DI 10.1016/S0039-6028(96)01156-9 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WL521 UT WOS:A1997WL52100013 ER PT J AU Yoon, HA Salmeron, M Somorjai, GA AF Yoon, HA Salmeron, M Somorjai, GA TI Scanning tunneling microscopy (STM) study of benzene and its coadsorption with carbon monoxide on Rh(111) SO SURFACE SCIENCE LA English DT Article DE aromatics; carbon monoxide; low index single crystal surfaces; rhodium; scanning tunneling microscopy; surface diffusion; surface structure ID CRYSTAL-SURFACE; COADSORBED BENZENE; CO; SPECTROSCOPY; MOLECULES; PT(111); LEED AB The surface structures of benzene and coadsorbed benzene/carbon monoxide on a Rh(lll) surface have been studied using scanning tunneling microscopy (STM). Benzene does not form a well-ordered overlayer on Rh(111), even at saturation coverage. When the coverage is approximate to 0.5 monolayer, only the benzene molecules at the top side of the step edges were imaged, while those on the terraces could not be detected by the STM owing to rapid diffusion. Coadsorption of carbon monoxide decreased the mobility of benzene which could then be imaged by STM. It was also found that carbon monoxide enhanced the surface ordering by formation of coadsorbed benzene/CO overlayers. The attractive interaction between benzene and carbon monoxide on Rh(111) surface contributes to the inhibition of the benzene diffusion and the enhancement of the surface overlayer ordering. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 24 TC 34 Z9 34 U1 1 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAR 1 PY 1997 VL 373 IS 2-3 BP 300 EP 306 DI 10.1016/S0039-6028(96)01165-X PG 7 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WL521 UT WOS:A1997WL52100014 ER PT J AU Hunter, WJ Follett, RF Cary, JW AF Hunter, WJ Follett, RF Cary, JW TI Use of vegetable oil to remove nitrate from flowing groundwater SO TRANSACTIONS OF THE ASAE LA English DT Article DE denitrification; groundwater; nitrate; nitrite; oil; wastewater; water; water quality ID DENITRIFICATION; WATER; CARBON; REDUCTION; SYSTEMS; SOIL AB This study investigated the use of vegetable oil to cleanse nitrate from groundwater: The hypothesis on which the study was based was that oil trapped in the sail matrix would form an immobile organic zone through which water flows; nitrate in the water would be removed as microbial denitrifiers utilized the oil as a carbon source. Laboratory studies show that the procedure has merit. Both corn and soybean oil rapidly stimulated native bacteria to remove nitrate from water in static anaerobic bioreactors. Soybean oil/water mixtures ranging from 0.8 to 12.5% oil in water were tested and all were effective at supporting denitrification. Also, denitrification occurred rapidly at nitrate concentrations up to 2000 ppm NO3-N. In addition to studies with static bioreactors, soil column studies were conducted. Soybean oil injected into 2.5 x 34 cm columns containing aquifer matrix or sand removed nitrate from flowing water Flow rates of Icp to 600 mL/day were successful. Innocuous vegetable oil may provide the basis for a simple and inexpensive method of nitrate removal from contaminated groundwater. C1 BATTELLE NW LABS, RICHLAND, WA USA. RP Hunter, WJ (reprint author), USDA ARS, SOIL PLANT NUTRIENT RES UNIT, POB E, FT COLLINS, CO 80522 USA. NR 35 TC 33 Z9 34 U1 1 U2 5 PU AMER SOC AGRICULTURAL & BIOLOGICAL ENGINEERS PI ST JOSEPH PA 2950 NILES RD, ST JOSEPH, MI 49085-9659 USA SN 0001-2351 J9 T ASAE JI Trans. ASAE PD MAR-APR PY 1997 VL 40 IS 2 BP 345 EP 353 PG 9 WC Agricultural Engineering SC Agriculture GA WZ038 UT WOS:A1997WZ03800007 ER PT J AU Wang, MQ AF Wang, MQ TI Mobile source emission control cost-effectiveness: Uncertainties, and results SO TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT LA English DT Article; Proceedings Paper CT Reformulated Fuels Conference CY JAN 31-FEB 02, 1995 CL HOUSTON, TX AB Government agencies and private organizations often use cost-effectiveness, calculated in dollars per ton of emissions reduced for various control measures, to determine which control measures should be implemented to meet emission reduction requirements. Different studies may, however, yield significantly different, sometimes contradicting, results for the same control measures. The results differ because of the various calculation methodologies used and assumptions made about the values of costs and emission reductions. This paper examines some important methodological issues involved in calculating the cost-effectiveness of mobile source control measures and proposes appropriate methods for calculating cost-effectiveness. Included are such issues as using user costs or societal costs, using costs at the manufacturer or the consumer level, determining baseline emissions, using emission reductions in nonattainment or in both nonattainment and attainment areas, using annual or pollution-season emission reductions, considering multiple-pollutant emission reductions, and applying emission discounting. This paper then reviews methodologies used in 11 studies recently completed in the United States on the cost effectiveness of mobile source control measures. On the basis of the methods proposed here for addressing the above issues, the original estimates in each study are modified to correct inconsistent or inappropriate methods so that the studies are comparable. From the adjusted results, the paper presents relative cost-effectiveness of 19 mobile source emission control measures. RP Wang, MQ (reprint author), ARGONNE NATL LAB, CTR TRANSPORTAT RES, ESD-362-B215, ARGONNE, IL 60439 USA. NR 20 TC 11 Z9 11 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1361-9209 J9 TRANSPORT RES D-TR E JI Transport. Res. Part D-Transport. Environ. PD MAR PY 1997 VL 2 IS 1 BP 43 EP 56 DI 10.1016/S1361-9209(96)00017-X PG 14 WC Environmental Studies; Transportation; Transportation Science & Technology SC Environmental Sciences & Ecology; Transportation GA WQ199 UT WOS:A1997WQ19900004 ER PT J AU Schipper, L Scholl, L Price, L AF Schipper, L Scholl, L Price, L TI Energy use and carbon emissions from freight in 10 industrialized countries: An analysis of trends from 1973 to 1992 SO TRANSPORTATION RESEARCH PART D-TRANSPORT AND ENVIRONMENT LA English DT Article AB This paper reviews trends in freight activity and energy use in 10 industrialized countries from 1973 to 1992. We review changes in modes used to carry freight and analyze changes in the role of trucks. We carry out a decomposition of changes in freight energy use to identify the relative contribution of activity, modal structure, and energy intensity to the rise in energy use observed in each country. A similar analysis is carried out for carbon emissions, one of the many environmental problems associated with freight. Our three major findings are: (1) domestic freight volumes rose, with trucks carrying most of the increment, in almost every country we studied, (2) freight energy use and associated carbon emissions increased markedly and are rising vis-a-vis those associated with passenger travel in the 10 industrialized countries studied, and (3) energy use for freight will continue to rise unless there are substantial reductions in the energy intensities of truck freight. We conclude that restraining or reducing emissions from freight will be particularly difficult because the factors that increased energy use and emissions for freight in the past are still important to raising energy use for freight. Noting that emissions from most other sectors have either fallen or grown less than freight, we discuss technologies and policies that might lead to restraint in this sector in the future. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENERGY ANAL PROGRAM,BERKELEY,CA 94720. NR 28 TC 80 Z9 81 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1361-9209 J9 TRANSPORT RES D-TR E JI Transport. Res. Part D-Transport. Environ. PD MAR PY 1997 VL 2 IS 1 BP 57 EP 76 DI 10.1016/S1361-9209(96)00014-4 PG 20 WC Environmental Studies; Transportation; Transportation Science & Technology SC Environmental Sciences & Ecology; Transportation GA WQ199 UT WOS:A1997WQ19900005 ER PT J AU Gardiner, K Brookes, A Mural, R AF Gardiner, K Brookes, A Mural, R TI Of messages and meaning SO TRENDS IN GENETICS LA English DT Editorial Material C1 MRC,HUMAN GENET UNIT,EDINBURGH EH4 2XU,MIDLOTHIAN,SCOTLAND. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Gardiner, K (reprint author), ELEANOR ROOSEVELT INST CANC RES,DENVER,CO 80206, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0168-9525 J9 TRENDS GENET JI Trends Genet. PD MAR PY 1997 VL 13 IS 3 BP 92 EP 93 DI 10.1016/S0168-9525(97)01067-6 PG 2 WC Genetics & Heredity SC Genetics & Heredity GA WM039 UT WOS:A1997WM03900004 PM 9066266 ER PT J AU Metting, FB Romine, MF AF Metting, FB Romine, MF TI Microbial genomics: The floodgates open SO TRENDS IN MICROBIOLOGY LA English DT Article RP Metting, FB (reprint author), PACIFIC NW LAB, 901 BATTELLE BLVD, RICHLAND, WA 99352 USA. NR 2 TC 10 Z9 10 U1 0 U2 1 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0966-842X J9 TRENDS MICROBIOL JI Trends Microbiol. PD MAR PY 1997 VL 5 IS 3 BP 91 EP 92 PG 2 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA WM746 UT WOS:A1997WM74600004 PM 9080605 ER PT J AU Tilinin, IS Betz, G AF Tilinin, IS Betz, G TI Backscattering of light atomic particles from solids SO VACUUM LA English DT Article; Proceedings Paper CT 18th Annual International Seminar on Surface Physics CY JUN 10-14, 1996 CL POLANICA ZDROJ, POLAND SP Univ Wroclaw, Inst Exptl Phys, European Phys Soc, Polish Minist Educ, Fdn Polish-German Cooperat, Univ Wroclaw, Fdn Univ Wroclaw, Stefaan Batory Fdn, Int Sci Fdn ID REFLECTION; IONS; COMPUTER AB Thermonuclear plasma-wall interaction is accompanied by intensive backscattering of light ions and atoms, which influences strongly the mass and energy transfer between the plasma and construction materials. Backscattering of atomic particles from solids plays an important role in the modification of materials by ion beams and also as a means of studying the near surface region by low energy ion scattering spectroscopy. In this report, the reflection of medium energy ions and atoms from thick targets has been studied both analytically and via computer simulations. A new method of solving the kinetic equation, with an appropriate boundary condition, has been developed, which enables simple and effective expressions to be obtained for the total particle energies and total reflection coefficients. The elastic scattering is described by realistic potentials, while inelastic energy losses are accounted for in the local density approximation. The analytical results compare well with the corresponding Monte Carlo calculations. (C) 1997 Elsevier Science Ltd. C1 VIENNA TECH UNIV,INST ALLGEMEINE PHYS,A-1040 VIENNA,AUSTRIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RP Tilinin, IS (reprint author), POLISH ACAD SCI,INST PHYS CHEM,KASPRZAKA 44-52,PL-01224 WARSAW,POLAND. NR 30 TC 2 Z9 2 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0042-207X J9 VACUUM JI Vacuum PD MAR-APR PY 1997 VL 48 IS 3-4 BP 395 EP 398 DI 10.1016/S0042-207X(96)00295-3 PG 4 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WR399 UT WOS:A1997WR39900045 ER PT J AU Norton, MV DiGiano, FA Hallen, RT AF Norton, MV DiGiano, FA Hallen, RT TI Selective separation of europium using polymer-enhanced ultrafiltration SO WATER ENVIRONMENT RESEARCH LA English DT Article DE americium; europium; ion exchange; metal-polymer binding; metal removal; polyacrylic acid; ultrafiltration AB The U.S. Department of Energy (DOE) is actively pur suing new and improved separation techniques for the cleanup of past nuclear defense production sites. Research and production activities at DOE's Hanford Site in Richland, Wash., have created large volumes of waste streams containing hazardous and toxic chemicals along with radioactive materials. Many of these wastes will require processing for segregation into high-level, transuranic, and/or low-level waste for permanent disposal. A process to selectively remove actinides, such as americium, from liquid radioactive waste was investigated for potential use at Hanford and other contaminated DOE sites. The objective of this research was to determine the effectiveness of polymer binding followed by ultrafiltration for removal of europium (Eu), a nonradioactive surrogate for trivalent actinides such as americium. A commercially available polyacrylic acid (PAA) and a Pacific Northwest Laboratory (PNL) synthesized copolymer were tested. Both polymers significantly increased Eu removal. A cation exchange mechanism was implied by examination of the Eu-to-RCO(2)(-) functional groups that comprise the acrylic acid monomer. The weight ratios of Eu-to-polymer needed to achieve 85% rejection of Eu were 1:6 for PAA and 1:10 for the PNL copolymer. Addition of sodium to the feed solution at a concentration three orders of magnitude greater than Eu did not adversely affect rejection of Eu; this showed the high selectivity of both polymers for Eu. Polymer binding of metals followed by ultrafiltration also has potential applications for selective separation of metals from various industrial process streams. The formation of metal hydroxide precipitates is also a possibility unless pH is controlled; these could be separated as well by ultrafiltration but defeat the intent of polymer addition. For the polymers tested, pH had to be above the pK(a) (4.25) of the ionizing functional groups but below a pH of 6 where precipitation may interfere. C1 UNIV N CAROLINA, DEPT ENVIRONM SCI & ENGN, CHAPEL HILL, NC USA. PACIFIC NW LAB, RICHLAND, WA USA. RP Norton, MV (reprint author), GRAY & OSBORNE INC, 701 DEXTER AVE N, SUITE 200, SEATTLE, WA 98109 USA. NR 12 TC 11 Z9 11 U1 0 U2 4 PU WATER ENVIRONMENT FEDERATION PI ALEXANDRIA PA 601 WYTHE ST, ALEXANDRIA, VA 22314-1994 SN 1061-4303 J9 WATER ENVIRON RES JI Water Environ. Res. PD MAR-APR PY 1997 VL 69 IS 2 BP 244 EP 253 DI 10.2175/106143097X125416 PG 10 WC Engineering, Environmental; Environmental Sciences; Limnology; Water Resources SC Engineering; Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA WL725 UT WOS:A1997WL72500017 ER PT J AU Vasco, DW DattaGupta, A Long, JCS AF Vasco, DW DattaGupta, A Long, JCS TI Resolution and uncertainty in hydrologic characterization SO WATER RESOURCES RESEARCH LA English DT Article ID INVERSE PROBLEMS; MEDIA AB Hydrologists have applied inverse techniques to obtain estimates of subsurface permeability and porosity variations and their associated uncertainties. Although inverse methods are now well established in hydrology, important aspects of inverse theory, the analysis of resolution, and the trade-off between model parameter resolution and model parameter uncertainty have not been utilized. In this paper the concept of model parameter resolution is incorporated into the analysis of hydrological experiments. Model parameter resolution is a measure of the spatial averaging implicit in estimates of a distributed hydrological property such as permeability. There are two important uses of resolution and uncertainty estimates in hydrology. The first use is to plan a hydrologic testing program. Resolution matrices can be developed for proposed well tests in a variety of synthetic media. Then the effectiveness of the test design can be evaluated in terms of model parameter resolution and uncertainty. Secondly, when real data are available and used in an inversion determining the distribution of hydrologic parameters, estimates of model parameter resolution and uncertainty analysis can indicate the reliability of the solution. For synthetic tests in which the hydraulic conductivity varies and porosity does not, it is found that tracer data can provide better spatial resolution of subsurface hydraulic conductivity variations than transient pressure data. Pressure data are most sensitive to hydraulic conductivity variations immediately surrounding the well. Both pressure and tracer data better determine barriers to flow rather than channels to flow. The methodology is applied to a set of transient pressure data gathered at the Grimsel Rock Laboratory of the Swiss National Cooperative for the Storage of Radioactive Waste. In the fracture under study a low hydraulic conductivity region appears to partition the fracture plane into two distinct zones. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV EARTH SCI,BERKELEY,CA 94720. RP Vasco, DW (reprint author), TEXAS A&M UNIV,DEPT PETR ENGN,COLLEGE STN,TX 77843, USA. RI Vasco, Donald/I-3167-2016 OI Vasco, Donald/0000-0003-1210-8628 NR 25 TC 42 Z9 42 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAR PY 1997 VL 33 IS 3 BP 379 EP 397 DI 10.1029/96WR03301 PG 19 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA WK638 UT WOS:A1997WK63800002 ER PT J AU Blau, PJ Ludema, KC Rhee, SK Glaeser, WA Ruff, AW Bahadur, S Bayer, RG Rigney, DA Vingsbo, O LarsenBasse, J AF Blau, PJ Ludema, KC Rhee, SK Glaeser, WA Ruff, AW Bahadur, S Bayer, RG Rigney, DA Vingsbo, O LarsenBasse, J TI The birth and history of the International Conferences on Wear of Materials SO WEAR LA English DT Editorial Material AB The International Wear of Materials (WoM) Conference series has experienced a colorful history of changes. from the struggles of its founders and the difficulties of finding suitable publishers for its papers, to the latest organizational experiment in coordinating with another major conference, In the face of minimal technical society support, steadfast efforts by the Steering Committee, enthusiastic volunteers, and a host of international paper solicitors have permitted the conference to survive and even to flourish, Throughout the years, the conference has reflected the trends in materials tribology research and has developed a loyal following. The success of the WoM conference series has flowed directly from the confluence of four basic elements: a special focus on wear of materials, the use of a rigorous review and editing process for all the papers submitted, an organization based on an independent group of tribology researchers with diverse but complementary backgrounds, and, lastly, a willingness to experiment with all aspects of the conference, including the choice of conference sites, sponsoring organizations, and publishers for the proceedings. It is impossible to know what form the WoM conference series will take in 1999 or beyond, While the paper publication situation seems to have been resolved for the moment, who will manage the future conferences has not. Thanks to past efforts, important contributions to understanding and using tribomaterials and to the stimulation of new research on wear-resistant materials are a lingering legacy. It will take the enthusiastic work of many selfless and dedicated individuals to continue the fine traditions established in the first twenty years of WoM. (C) 1997 Elsevier Science S.A. C1 UNIV MICHIGAN,DEPT MECH ENGN,ANN ARBOR,MI 48109. ALLIED SIGNAL BRAKING SYST INC,TROY,MI 48084. BATTELLE MEM INST,COLUMBUS LABS,COLUMBUS,OH 43201. NIST,DIV CERAM,GAITHERSBURG,MD 20899. IOWA STATE UNIV,DEPT MECH ENGN,AMES,IA 50011. OHIO STATE UNIV,COLUMBUS,OH 43210. UPPSALA UNIV,S-75121 UPPSALA,SWEDEN. NATL SCI FDN,ARLINGTON,VA 22230. RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 0 TC 1 Z9 1 U1 1 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 1 EP 10 DI 10.1016/S0043-1648(96)07407-8 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300004 ER PT J AU Chen, Z Liu, P Verhoeven, JD Gibson, ED AF Chen, Z Liu, P Verhoeven, JD Gibson, ED TI Electrotribological behavior of Cu-15 vol% Cr in situ composites under dry sliding SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE electrotribology; dry sliding; Cu-Cr composite ID STRENGTH; ALLOYS AB The Cu-15 vol.% Cr in situ composite is a promising material for the electrical contacts in high current devices, since it has an excellent combination of mechanical strength and electrical/thermal conductivity. The electrotribological behavior of Cu-15 vol.% Cr was studied using a modified pin-on-disk tester with an electrical current applied across the sliding interface. The Cu-15 vol.% Cr pins were slid against a hardened AISI 52100 steel disk under dry ambient conditions. Coefficient of friction, wear rate and bulk temperature of the composite pins were evaluated as a function of electrical current, normal pressure and sliding speed. The microstructural change in the composite due to electrical sliding was related to the electrotribological behavior. Within the studied range of electrical current, normal pressure and sliding speed, the coefficient of friction and the wear rate decreased wifh increasing electrical current, whereas the bulk temperature increased. A deformed subsurface layer was identified in the composite after electrical sliding. The thickness of the subsurface layer decreased with increasing electrical current. The surface layer, containing refined structure,wear debris and back transferred materials from the steel disk, had a high level of microhardness. C1 IOWA STATE UNIV,DEPT MAT SCI & ENGN,US DOE,AMES LAB,AMES,IA 50011. RP Chen, Z (reprint author), EASTERN ILLINOIS UNIV,SCH TECHNOL,CHARLESTON,IL 61920, USA. NR 11 TC 6 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 28 EP 35 DI 10.1016/S0043-1648(96)07368-1 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300007 ER PT J AU Liu, P Bahadur, S Verhoeven, JD Gibson, ED Kristiansen, M Donaldson, A AF Liu, P Bahadur, S Verhoeven, JD Gibson, ED Kristiansen, M Donaldson, A TI Arc erosion behavior of Cu-15%Nb and Cu-15%Cr in situ composites SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE arc erosion; low energy; high energy ID ELECTRODE EROSION AB The are erosion behavior of Cu-15%Nb and Cu-15%Cr in situ composites was studied for both low-energy make-and-break contact and a high-energy stationary arcing gap configuration. For low-energy make-and-break contacts, a computerized test set-up was developed, while the high-energy pulsed power stationary arcing tests were performed in the Mark VI facility at Texas Tech University, Lubbock, TX. The study dealt with variation in contact resistance for make-and-break contacts, are erosion at both energy levels, and materials response to are erosion. The surface films formed in the make-and-break operation were analyzed by an X-ray diffraction technique, and the eroded surfaces and are erosion mechanisms were studied by scanning electron microscopy. It was concluded that in low-energy contacts, oxidation was the major cause of deterioration of electrical contacts, while melting was the major failure mode in high-energy contacts. The contact resistance of Cu-15%Nb was much lower than that of Cu-15%Cr. The are erosion resistance of Cu-15%Nb and Cu-15%Cr was higher than that of the commercially used Cu-W composite in stationary are erosion tests. (C) 1997 Elsevier Science S.A. C1 IOWA STATE UNIV,DEPT MECH ENGN,AMES,IA 50011. IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. TEXAS TECH UNIV,DEPT ELECT ENGN,LUBBOCK,TX 79409. GREENVILLE COLL,DEPT PHYS,GREENVILLE,IL 62246. RP Liu, P (reprint author), EASTERN ILLINOIS UNIV,SCH TECHNOL,CHARLESTON,IL 61920, USA. NR 19 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 36 EP 45 DI 10.1016/S0043-1648(96)07394-2 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300008 ER PT J AU Hawk, JA Alman, DE Petrovic, JJ AF Hawk, JA Alman, DE Petrovic, JJ TI Abrasive wear of Si3N4-MoSi2 composites SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE abrasion; composites; silicon nitride; molybdenum; disilicide; rule of mixtures ID REINFORCED SILICON-NITRIDE; FRACTURE-TOUGHNESS; IMPACT DAMAGE; MICROSTRUCTURE; CERAMICS; BEHAVIOR; RESISTANCE; ALUMINA; MOSI2 AB Molybdenum disilicide (MoSi2) particles have been added to silicon nitride (Si3N4) to form ceramic matrix-intermetallic composites. Benefits associated with the addition of the MoSi2 to Si3N4 include higher strength, higher fracture toughness, no loss in oxidation resistance, and lower electrical resistivity. However, since the hardness of MoSi2 is approximately half that of Si3N4, a significant decrease in the specific wear rate of the Si3N4-MoSi2 composites is expected to result from the incorporation of the MoSi2 in the Si3N4. In this study, it was found, however, that the wear resistance of Si3N4 improves slightly or is unaffected by additions of small volume fractions (less than or equal to 20%) of MoSi2 particles, during two-body abrasion by SiC particles. At higher volume fractions, the Si3N4-MoSi2 composites wear at rates no greater than 1.5 times that of monolithic Si3N4. The volume wear of the composites was dependent on composite hardness, fracture toughness and microstructural features (i.e. MoSi2 particle size). Given equivalent hardness and fracture toughness for a composite pair at the same volume fraction, however, the composite with the smaller MoSi2 particles exhibited the lower wear rate. The abrasive wear behavior of the Si3N4-MoSi2 composites can be described in terms of the inverse rule of mixtures for composites. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Hawk, JA (reprint author), US DOE,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 33 TC 39 Z9 62 U1 0 U2 5 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 247 EP 256 DI 10.1016/S0043-1648(96)07380-2 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300030 ER PT J AU Adler, TA Dogan, ON AF Adler, TA Dogan, ON TI Damage by indentation and single impact of hard particles on a high chromium white cast iron SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE white cast iron; erosion; impact; indentation; strain hardening; strain localization ID ELASTIC-PLASTIC INDENTATION; EROSION; IMPINGEMENT; MODEL; DEFORMATION; ALUMINUM; ABRASION; METALS AB High chromium white cast irons are used extensively in environments where small particle impact causes considerable damage. In this study, a white cast iron containing 26 wt% Cr, and with a carbide volume fraction of 0.28, is impacted with projectiles at normal incidence using a gas gun. Both crater diameter and the size of the damage zone are measured as a function of projectile velocity, and an analytical model is developed which relates the size of the impact crater to the energy absorbed by plastic and elastic deformation of the white cast iron. Peak impact loads and strain hardening rates during impact are calculated by comparing the impact craters with craters made by quasi-static indentation. It is found that considerable strain hardening occurs in austenitic white cast irons during impact and indentation. Strain localization and dynamic softening are also observed in these materials at higher impact velocities. (C) 1997 Elsevier Science S.A. RP Adler, TA (reprint author), US DOE,ALBANY RES CTR,ALBANY,OR 97321, USA. NR 35 TC 16 Z9 17 U1 3 U2 10 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 257 EP 266 DI 10.1016/S0043-1648(96)07435-2 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300031 ER PT J AU Dogan, CP Hawk, JA AF Dogan, CP Hawk, JA TI Influence of whisker reinforcement on the abrasive wear behavior of silicon nitride- and alumina-based composites SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE composites; abrasive wear; silicon nitride; alumina; microstructure ID FRACTURE-TOUGHNESS; MATRIX COMPOSITES; CERAMIC MATERIALS; GRAIN-SIZE; MICROSTRUCTURE; MECHANISMS; CARBIDE; AL2O3 AB The abrasive wear of brittle materials, while not a true property of materials, is generally modeled as an inverse function of both the bulk hardness and fracture toughness. According to these models, an increase in the hardness and/or fracture toughness of a material will therefore enhance its wear resistance. In ceramic materials, the addition of whisker reinforcement is a proven method of enhancing long-crack fracture toughness via such mechanisms as crack bridging and whisker debonding. However, less is known about how whisker reinforcement influences the properties that are dependent upon the short-crack toughness, such as abrasive wear. The results of this study indicate that while the addition of randomly oriented SiC whiskers can dramatically improve the abrasive wear resistance of an alumina-based ceramic, the addition of SiC reinforcement to silicon nitride ceramics does not always result in improved wear resistance. This variation in the influence of whisker reinforcement on wear behavior is attributed to the residual stress state created in the composites as a result of the addition of the second phase whiskers. RP Dogan, CP (reprint author), ALBANY RES CTR,DEPT ENERGY,ALBANY,OR 97321, USA. NR 31 TC 18 Z9 18 U1 2 U2 4 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 267 EP 277 DI 10.1016/S0043-1648(96)07348-6 PG 11 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300032 ER PT J AU Bahadur, S Zhang, L Anderegg, JW AF Bahadur, S Zhang, L Anderegg, JW TI The effect of zinc and copper oxides and other zinc compounds as fillers on the tribological behavior of thermosetting polyester SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE friction; wear; inorganic fillers; transfer film; XPS studies ID TRANSFER FILM; WEAR; POLYTETRAFLUOROETHYLENE; NYLON; CUS AB The tribological behavior of thermosetting polyester filled with CuO, ZnO, ZnF2, and Zn(C18H35O2)(2) fillers was studied. Sliding was performed in ambient atmosphere at 1.0 m s(-1) between a polyester pin and a hardened tool steel disk in a pin-on-disk machine. The worn and the unworn specimen pin surfaces, zinc stearate powder, and the transfer films formed during sliding were studied by X-ray photoelectron spectroscopy (XPS). It was found that the coefficients of friction of all the filled composites were higher than that of the unfilled polyester. As for wear, the wear rate of polyester filled with ZnO and ZnF2 increased while that of polyester filled with CuO and Zn(C18H35O2)(2) decreased. The reasons for these kinds of behavior were investigated. XPS results revealed that the Zn(C18H35O2)(2) filler decomposed during the sliding process while ZnO did not. It has been hypothesized that decomposition of the filler helps in bonding of the transfer film to the counterface. The observed behavior is explained in terms of the topographical features, morphology and bonding of the transfer film to its counterface. (C) 1997 Elsevier Science S.A. C1 US DOE,AMES LAB,AMES,IA 50011. RP Bahadur, S (reprint author), IOWA STATE UNIV,DEPT ENGN MECH,AMES,IA 50011, USA. NR 20 TC 29 Z9 32 U1 1 U2 6 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 464 EP 473 DI 10.1016/S0043-1648(96)07445-5 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300055 ER PT J AU Erdemir, A Erck, RA Fenske, GR Hong, H AF Erdemir, A Erck, RA Fenske, GR Hong, H TI Solid/liquid lubrication of ceramics at elevated temperatures SO WEAR LA English DT Article; Proceedings Paper CT 11th International Conference on Wear of Materials (WoM 97) CY APR 20-23, 1997 CL SAN DIEGO, CA DE ceramics; high-temperature lubrication; lubrication mechanism; synthetic oil; silver film ID LIQUID LUBRICATION; SLIDING FRICTION; WEAR; PERFORMANCE; BEHAVIOR; METAL AB This study investigates the effects of solid and liquid lubrication on the friction and wear performance of silicon nitride (Si3N4) and gray cast iron. The solid lubricant was a thin silver film (similar to 2 mu m thick) produced on Si3N4 by ion-beam-assisted deposition. A high-temperature polyol-ester-base synthetic oil served as the liquid lubricant. Friction and wear tests were performed with pin-on-disk and oscillating-slider wear test machines at temperatures up to 300 degrees C. Without the silver films, the friction coefficients of Si3N4/Si3N4 test pairs were 0.05-0.14, and the average wear rates of Si3N4 pins were similar to 5 x 10(-8) mm(3) N-1 m(-1). The friction coefficients of Si3N4/cast iron test pairs ranged from 0.08 to 0.11, depending on test temperature. The average specific wear rates of cast iron pins were similar to 3 X 10(-7) mm(3) N-1 m(-1). However, simultaneous use of the solid-lubricant silver and synthetic oil on the sliding surfaces reduced friction coefficients to 0.02-0.08. Moreover, the wear of Si,N, pins and silver-coated Si,N, disks was so low that it was difficult to assess by a surface profilometer. The wear rates of cast iron pins were similar to 7 x 10(-9) mm(3) N-1 m(-1) up to 250 degrees C, but showed a tendency to increase slightly at higher temperatures. In general, the test results demonstrated that the solid/liquid lubrication of ceramic and/or metallic components is both feasible and effective in controlling friction and wear. (C) 1997 Elsevier Science S.A. C1 LUBRIZOL CORP,WICKLIFFE,OH 44092. RP Erdemir, A (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,ARGONNE,IL 60439, USA. NR 31 TC 31 Z9 34 U1 3 U2 19 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 588 EP 595 DI 10.1016/S0043-1648(96)07431-5 PG 8 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300067 ER PT J AU Blau, PJ Martin, RL Zanoria, ES AF Blau, PJ Martin, RL Zanoria, ES TI Effects of surface grinding conditions on the reciprocating friction and wear behavior of silicon nitride SO WEAR LA English DT Article DE friction; wear; silicon nitride; surface finish; ground ceramics; grinding AB The relationship between two significantly different surface grinding conditions and the reciprocating ball-on-flat friction and wear behavior of a high-quality, structural silicon nitride material (GS-44) was investigated. The slider materials were silicon nitride NBD 200 and 440C stainless steel. Two machining conditions were selected based on extensive machining and flexural strength test data obtained under the auspices of an international, interlaboratory grinding study. The condition categorized as ''low strength'' grinding used a coarse 80 grit wheel and produced low flexure strength due to machining-induced flaws in the surface. The other condition, regarded as ''high strength grinding,'' utilized a 320 grit wheel and produced a flexural strength nearly 70% greater. Grinding wheel surface speeds were 35 and 47 ms(-1) Reciprocating sliding tests were conducted following the procedure described in a newly published ASTM standard (G-133) for linearly reciprocating wear. Tests were performed in directions both parallel and perpendicular to the grinding marks (lay) using a 25 N load, 5 Hz reciprocating frequency, 10 mm stroke length, and 100 m of sliding at room temperature. The effects of sliding direction relative to the lay were more pronounced for stainless steel than for silicon nitride sliders. The wear of stainless steel was less than the wear of the silicon nitride slider materials because of the formation of transfer particles which covered the sharp edges of the silicon nitride grinding grooves and reduced abrasive contact. The wear of the GS-44 material was much greater for the silicon nitride sliders than for the stainless steel sliders. The causes for the effects of surface grinding severity and sliding direction on friction and wear of GS-44 and its counterface materials are explained. (C) 1997 Elsevier Science S.A. RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 8 TC 13 Z9 13 U1 2 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP 648 EP 657 DI 10.1016/S0043-1648(96)07460-1 PG 10 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300074 ER PT J AU Blau, PJ AF Blau, PJ TI Message from the Conference Chair SO WEAR LA English DT Editorial Material RP Blau, PJ (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0043-1648 J9 WEAR JI Wear PD MAR PY 1997 VL 203 BP R10 EP R10 PG 1 WC Engineering, Mechanical; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WV203 UT WOS:A1997WV20300002 ER PT J AU Vianco, PT AF Vianco, PT TI Solder alloys: A look at the past, present and future SO WELDING JOURNAL LA English DT Article RP Vianco, PT (reprint author), SANDIA NATL LABS,CTR SOLDER SCI & TECHNOL,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 16 TC 2 Z9 2 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 MAR PY 1997 VL 76 IS 3 BP 45 EP 49 PG 5 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA WM118 UT WOS:A1997WM11800014 ER PT J AU Fuerschbach, PW Hinkley, DA AF Fuerschbach, PW Hinkley, DA TI Pulsed Nd:YAG laser welding of cardiac pacemaker batteries with reduced heat input SO WELDING JOURNAL LA English DT Article DE pulsed Nd:YAG; pacemaker; medical battery; glass-to-metal seal; response surface; melting efficiency; 304L stainless steel; hermeticity; high reliability; heat input AB The effects of Nd:YAG laser beam welding process parameters on the resulting heat input in 304L stainless steel cardiac pacemaker batteries have been studied. By careful selection of process parameters, the results can be used to reduce temperatures near glass-to-metal seals and assure hermeticity in laser beam welding of high reliability components. Three designed response surface experiments were used to compare welding performance with lenses of varying focal lengths. The measured peak temperatures al the glass-to-metal seals varied from 65 degrees to 140 degrees C (149 degrees to 284 degrees F) and depended strongly on the levels of the experimental factors. It was found that welds of equivalent size can be made with significantly reduced temperatures. The reduction in battery temperatures has been attributed to an increase in the melting efficiency. This increase is thought to be due primarily to increased travel speeds, which were facilitated by high peak powers and low pulse energies. For longer focal length lenses, weld fusion zone widths were found to be greater even without a corresponding increase in the size of the weld. It was also found that increases in laser beam irradiance either by higher peak powers or smaller spot sizes created deeper and larger welds. These gains were attributed to an increase in the laser energy transfer efficiency. RP Fuerschbach, PW (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 17 TC 9 Z9 9 U1 1 U2 4 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 SN 0043-2296 J9 WELD J JI Weld. J. PD MAR PY 1997 VL 76 IS 3 BP S103 EP S109 PG 7 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA WM118 UT WOS:A1997WM11800019 ER PT J AU Forsman, ED Giese, AR AF Forsman, ED Giese, AR TI Nests of Northern Spotted Owls on the Olympic Peninsula, Washington SO WILSON BULLETIN LA English DT Article ID SITE SELECTION AB We located 155 nests in 82 territories occupied by Northern Spotted Owls (Strix occidentalis caurina) on the Olympic Peninsula, Washington. All nests were in trees. Of 116 nests that were measured, 105 were in cavities and 11 were in external platforms on tree limbs. Cavity nests were typically in large holes in the side of the trunk or in the broken top of the trunk. Aspect of cavity entrances was non-random, with the majority of cavities facing east-north-east. Location of nest trees did not differ from expected values for slope aspect or position on slope. Proportions of nest sites in different percent slope categories differed from availability, with more nests than expected in the higher percent slope categories. Nests usually were in stands with high overall canopy closure (greater than or equal to 70%), but canopy closure in the immediate vicinity of the nest varied from 35-90%. Most nests (87%) were in multilayered stands dominated by large trees. Nests in younger stands were typically in stands where remnant old trees were present. Owls changed nests between successive nesting events in 80% of all cases. Changes in pair members on a territory did not influence the frequency with which pairs switched to a new nest tree in the next nesting year. Based on observed rates of attrition, the expected life span of nests was 120 years. C1 OREGON STATE UNIV, DEPT WILDLIFE & FISHERIES, CORVALLIS, OR 97331 USA. RP Forsman, ED (reprint author), US FOREST SERV, PACIFIC NW LAB, USDA, 3200 SW JEFFERSON WAY, CORVALLIS, OR 97331 USA. NR 18 TC 16 Z9 16 U1 2 U2 5 PU WILSON ORNITHOLOGICAL SOC PI ANN ARBOR PA MUSEUM OF ZOOLOGY UNIV MICHIGAN, ANN ARBOR, MI 48109 SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD MAR PY 1997 VL 109 IS 1 BP 28 EP 41 PG 14 WC Ornithology SC Zoology GA WP229 UT WOS:A1997WP22900002 ER PT J AU Batchelder, JC Toth, KS Bingham, CR Brown, LT Conticchio, LF Davids, CN Davinson, T Henderson, DJ Irvine, RJ Seweryniak, D Walters, WB Woods, PJ Wauters, J Zganjar, EF AF Batchelder, JC Toth, KS Bingham, CR Brown, LT Conticchio, LF Davids, CN Davinson, T Henderson, DJ Irvine, RJ Seweryniak, D Walters, WB Woods, PJ Wauters, J Zganjar, EF TI The alpha-decay properties of Bi-186 SO ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI LA English DT Article ID ISOTOPES AB The alpha decay of Bi-186 was investigated via the Mo-97(Mo-92, p2n) reaction and the use of a fragment mass analyzer with a double-sided Si strip detector. In contrast to an earlier work wherein only one alpha transition was reported, we observed two transitions arising from two isomers in Bi-186 with energies and half-lives of: 7158(20) keV, T-1/2 = 15.0(17) ms; and 7261(20) keV, T-1/2 = 9.8(13) ms. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. UNIV TENNESSEE,KNOXVILLE,TN 37996. VANDERBILT UNIV,NASHVILLE,TN 37235. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV EDINBURGH,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND. RP Batchelder, JC (reprint author), LOUISIANA STATE UNIV,BATON ROUGE,LA 70803, USA. NR 10 TC 10 Z9 10 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0939-7922 J9 Z PHYS A-HADRON NUCL JI Z. Phys. A.-Hadrons Nuclei PD MAR PY 1997 VL 357 IS 2 BP 121 EP 122 DI 10.1007/s002180050223 PG 2 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA WQ465 UT WOS:A1997WQ46500001 ER PT J AU Ott, HR Chernikov, M Felder, E Degiorgi, L Moshopoulou, EG Sarrao, JL Fisk, Z AF Ott, HR Chernikov, M Felder, E Degiorgi, L Moshopoulou, EG Sarrao, JL Fisk, Z TI Structure and low temperature properties of SrB6 SO ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER LA English DT Article ID SINGLE-CRYSTAL DIFFRACTOMETRY; DIFFRACTION; DEPENDENCE AB A detailed study of the room temperature structure of high duality single crystalline SrB6 has been made. Minute changes in interatomic distances may drastically affect the electronic spectrum of this compound. Electronic transport properties both at zero and non-zero frequencies above He-4 temperatures indicate that SrB6 is close to be a semiconductor. However, at very low temperatures this compound enters a metallic state with a low concentration of itinerant charge carriers. Possible correlation effects are indicated by anomalous temperature dependences of the electrical resistivity and the specific heat below 1 K. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NATL HIGH MAGNET FIELD LAB, TALLAHASSEE, FL 32306 USA. RP Ott, HR (reprint author), ETH HONGGERBERG, FESTKORPERPHYS LAB, CH-8093 ZURICH, SWITZERLAND. NR 31 TC 68 Z9 68 U1 1 U2 9 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-3277 J9 Z PHYS B CON MAT JI Z. Phys. B-Condens. Mat. PD MAR PY 1997 VL 102 IS 3 BP 337 EP 345 DI 10.1007/s002570050297 PG 9 WC Physics, Condensed Matter SC Physics GA WN965 UT WOS:A1997WN96500007 ER PT J AU Degiorgi, L Thieme, S Ott, HR Dressel, M Gruner, G Dalichaouch, Y Maple, MB Fisk, Z Geibel, C Steglich, F AF Degiorgi, L Thieme, S Ott, HR Dressel, M Gruner, G Dalichaouch, Y Maple, MB Fisk, Z Geibel, C Steglich, F TI The electrodynamic response of heavy-electron materials with magnetic phase transitions SO ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER LA English DT Article ID CAVITY PERTURBATION TECHNIQUE; RELAXATION-TIME ENHANCEMENT; SUPERCONDUCTOR URU2SI2; COMPOUND U2ZN17; FERMI-SURFACE; POINT-CONTACT; GROUND-STATE; UPD2AL3; UCU5; SYSTEM AB We have investigated the electrodynamic response of the heavy-electron compounds U2Zn17, UPd2Al3, UCu5 and URu2Si2. Particular emphasis has been devoted to the optical evidence of the antiferromagnetic phase transitions at T-N = 9.7 K, 14 K, 15 K and 17 K for U2Zn17, UPd2Al3, UCu5 and URu2Si2, respectively. In the excitation spectrum of UCu5 and URu2Si2, we found an absorption in the far-infrared, which develops below T-N and is ascribed to the excitation across a spin-density-wave type gap, suggesting that the antiferromagnetic phase transition might be itinerant in nature, and invokes a Fermi surface instability. Since this gap-like feature is absent in U2Zn17 and UPd2Al3, we argue that these latter compounds belong to a characteristically different class of antiferromagnets, representative of the heavy-electron compounds with an ordering of essentially localized magnetic moments. The antiferromagnetic ordering then leads to a suppression of the spin-flip mechanism below T-N At low temperatures, we observe for all compounds the formation of a narrow Drude-like resonance in the optical conductivity, which is ascribed to the electrodynamic response of the heavy-quasiparticles, and is indicative of the progressive development of the many-body coherent Kondo state, coexisting with both types of magnetic ordering. In this review, we also present the evolution of the optical properties due to Ni- and Re-doping in UCu5 and URu2Si2, respectively. The optical evidence of the itinerant antiferromagnetic ordering is suppressed in both compounds upon doping and particularly for the URu2Si2 compound this is consistent with a crossover to a ferromagnetic ground state upon Re-doping. C1 UNIV CALIF LOS ANGELES, DEPT PHYS, LOS ANGELES, CA 90095 USA. UNIV CALIF SAN DIEGO, DEPT PHYS, LA JOLLA, CA 92093 USA. LOS ALAMOS NATL LAB, DIV MAT SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. TH DARMSTADT, INST FESTKORPERPHYS, D-64289 DARMSTADT, GERMANY. RP Degiorgi, L (reprint author), ETH ZURICH, FESTKORPERPHYS LAB, CH-8093 ZURICH, SWITZERLAND. RI Dressel, Martin/D-3244-2012 NR 58 TC 38 Z9 38 U1 2 U2 8 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0722-3277 J9 Z PHYS B CON MAT JI Z. Phys. B-Condens. Mat. PD MAR PY 1997 VL 102 IS 3 BP 367 EP 380 DI 10.1007/s002570050300 PG 14 WC Physics, Condensed Matter SC Physics GA WN965 UT WOS:A1997WN96500010 ER PT J AU Brignole, A Ibanez, LE Munoz, C Scheich, C AF Brignole, A Ibanez, LE Munoz, C Scheich, C TI Some issues in soft SUSY-breaking terms from dilaton vertical bar moduli sectors SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID PHENOMENOLOGICAL IMPLICATIONS; DIMENSIONAL REDUCTION; KAHLER POTENTIALS; VACUUM ENERGY; ZN ORBIFOLDS; SUPERSYMMETRY; SUPERGRAVITY; CONSTRAINTS; STRINGS; MODELS AB We study the structure of the soft SUSY-breaking terms obtained from some classes of 4-D strings under the assumption of dilaton/moduli dominance in the process of SUSY-breaking. We generalize previous analyses in several ways and in particular consider the new features appearing when several moduli fields contribute to SUSY breaking (instead of an overall modulus T). Some qualitative features indeed change in the multimoduli case. A general discussion for symmetric Abelian orbifolds as well as explicit examples are given. Certain general sum-rules involving soft terms of different particles are shown to apply to large classes of models. Unlike in the overall modulus T case, gauginos may be lighter than scalars even at the tree-level. However, if one insists in getting that pattern of soft terms, these sum rules force some of the scalars to get negative mass(2). These tachyonic masses could be a problem for standard model 4-D strings but an advantage in the case of string-GUTs. We also discuss the possible effects of off-diagonal metrics for the matter fields which may give rise to flavour-changing neutral currents. Different sources for the bilinear B soft term are studied. It is found that the Giudice-Masiero mechanism for generating a ''mu-term'', as naturally implemented in orbifolds, leads to the prediction \tg beta\ = 1 at the string scale, independently of the Goldstino direction. C1 UNIV AUTONOMA MADRID,DEPT FIS TEOR 100 11,E-28049 MADRID,SPAIN. RP Brignole, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 36 TC 119 Z9 119 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 MAR PY 1997 VL 74 IS 1 BP 157 EP 170 DI 10.1007/s002880050379 PG 14 WC Physics, Particles & Fields SC Physics GA WW234 UT WOS:A1997WW23400014 ER PT J AU Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Okrasiniski Jr Repond, J Stanek, R Talaga, RL Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Bruni, P Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M Gialas I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Crittenden, J Deffner, R Eckert, M Feld, L Frey, A Geerts, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Mengel, S Paul, E Pfeiffer, M Rembser, C Schramm, D Stamm, J Wedemeyer, R CampbellRobson, S Cassidy, A Cottingham, WN Dyce, N Foster, B George, S Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Yoshida, R Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sciulli, F Straub, PB Wai, L Yang, S Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycien, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Flasinski, M Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Joos, P Kasemann, M Klanner, R Koch, W Kotz, U Kowalski, H Labs, J Ladage, A Lohr, B Lowe, M Luke, D Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Piotrzkowski, K Roco, M Rohde, M Roldan, J Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zeuner, W Grabosch, HJ Mari, SM Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G DePasquale, S Votano, L Bamberger, A Eisenhardt, S Trefzger, T Wolfle, D Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Dannemann, A Holm, U Horstmann, D Sinkus, R Wick, K Burow, BD Hagge, L Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Brummer, N Butterworth I Harris, VL Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, MZ Wang, SM Wu, JT Cloth, P Filges, D An, SH Cho, GH Ko, BJ Lee, SB Nam, SW Park, HS Park, SK Kartik, S Kim, HJ McNeil, RR Metcalf, W Nadendla, VK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Matthews, CG Murray, WN Ochs, A Patel, PM Riveline, M Stairs, DG StLaurent, M Ullmann, R Zacek, G Tsurugai, T Bashkirov V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Gladilin, LK Golubkov, YA Kobrin, VD Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Savin, AA Shcheglova, LM Solomin, AN Zotov, NP Botje, M Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E vanWoudenberg, R Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Li, C Ling, TY Nylander, P Park, IH Romanowski, TA Bailey, DS Cashmore, RJ CooperSarkar, AM Devenish, RCE Harnew, N Lancaster, M Lindemann, L McFall, JD Nath, C Noyes, VA Quadt, A Tickner Jr Uijterwaal, H Walczak, R Waters, DS Wilson, FF Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F DeGiorgi, M Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Zuin, F Bulmahn, J Feild, RG Oh, BY Whitmore, JJ DAgostini, G Marini, G Nigro, A Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Biltzinger, J Seifert, RJ Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Levy, A Fleck, JI Inuzuka, M Ishii, T Kuze, M Mine, S Nakao, M Suzuki I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Chiba, M Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Peroni, C Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Benard, F Brkic, M Fagerstroem, CP Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Bogusz, W Ciborowski, J Gajewski, J Grzelak, G Kasprzak, M Krzanowski, M Muchorowski, K Nowak, RJ Pawlak, JM Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D ZerZion, D Badgett, WF Breitweg, J Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Silverstein, S Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Cardy, ML Frisken, WR Khakzad, M Schmidke, WB AF Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Okrasiniski, JR Repond, J Stanek, R Talaga, RL Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Bruni, P Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M Gialas, I Giusti, P Iacobucci, G Laurenti, G Levi, G Margotti, A Massam, T Nania, R Palmonari, F Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Crittenden, J Deffner, R Eckert, M Feld, L Frey, A Geerts, M Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Mengel, S Paul, E Pfeiffer, M Rembser, C Schramm, D Stamm, J Wedemeyer, R CampbellRobson, S Cassidy, A Cottingham, WN Dyce, N Foster, B George, S Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Yoshida, R Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sciulli, F Straub, PB Wai, L Yang, S Zhu, Q Borzemski, P Chwastowski, J Eskreys, A Jakubowski, Z Przybycien, MB Zachara, M Zawiejski, L Adamczyk, L Bednarek, B Jelen, K Kisielewska, D Kowalski, T Przybycien, M RulikowskaZarebska, E Suszycki, L Zajac, J Dulinski, Z Kotanski, A Abbiendi, G Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Flasinski, M Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Joos, P Kasemann, M Klanner, R Koch, W Kotz, U Kowalski, H Labs, J Ladage, A Lohr, B Lowe, M Luke, D Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Piotrzkowski, K Roco, M Rohde, M Roldan, J Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zeuner, W Grabosch, HJ Mari, SM Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G DePasquale, S Votano, L Bamberger, A Eisenhardt, S Trefzger, T Wolfle, D Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Dannemann, A Holm, U Horstmann, D Sinkus, R Wick, K Burow, BD Hagge, L Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Brummer, N Butterworth, I Harris, VL Howell, G Hung, BHY Lamberti, L Long, KR Miller, DB Pavel, N Prinias, A Sedgbeer, JK Sideris, D Whitfield, AF Mallik, U Wang, MZ Wang, SM Wu, JT Cloth, P Filges, D An, SH Cho, GH Ko, BJ Lee, SB Nam, SW Park, HS Park, SK Kartik, S Kim, HJ McNeil, RR Metcalf, W Nadendla, VK Barreiro, F Fernandez, JP Graciani, R Hernandez, JM Hervas, L Labarga, L Martinez, M delPeso, J Puga, J Terron, J deTroconiz, JF Corriveau, F Hanna, DS Hartmann, J Hung, LW Lim, JN Matthews, CG Murray, WN Ochs, A Patel, PM Riveline, M Stairs, DG StLaurent, M Ullmann, R Zacek, G Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Gladilin, LK Golubkov, YA Kobrin, VD Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Savin, AA Shcheglova, LM Solomin, AN Zotov, NP Botje, M Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E vanWoudenberg, R Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Li, C Ling, TY Nylander, P Park, IH Romanowski, TA Bailey, DS Cashmore, RJ CooperSarkar, AM Devenish, RCE Harnew, N Lancaster, M Lindemann, L McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Wilson, FF Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F DeGiorgi, M Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Zuin, F Bulmahn, J Feild, RG Oh, BY Whitmore, JJ DAgostini, G Marini, G Nigro, A Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Biltzinger, J Seifert, RJ Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Levy, A Fleck, JI Inuzuka, M Ishii, T Kuze, M Mine, S Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Chiba, M Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Peroni, C Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC Benard, F Brkic, M Fagerstroem, CP Hartner, GF Joo, KK Levman, GM Martin, JF Orr, RS Polenz, S Sampson, CR Simmons, D Teuscher, RJ Butterworth, JM Catterall, CD Jones, TW Kaziewicz, PB Lane, JB Saunders, RL Shulman, J Sutton, MR Lu, B Mo, LW Bogusz, W Ciborowski, J Gajewski, J Grzelak, G Kasprzak, M Krzanowski, M Muchorowski, K Nowak, RJ Pawlak, JM Tymieniecka, T Wroblewski, AK Zakrzewski, JA Zarnecki, AF Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D ZerZion, D Badgett, WF Breitweg, J Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Silverstein, S Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Cardy, ML Frisken, WR Khakzad, M Schmidke, WB TI Search for lepton flavor violation in ep collisions at 300 GeV center of mass energy SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; P(P)OVER-BAR COLLISIONS; PARTON DISTRIBUTIONS; SCALAR LEPTOQUARKS; MONTE-CARLO; Z0 DECAYS; CONSTRUCTION; DESIGN; CONVERSION AB Using the ZEUS detector at the HERA electron-proton collider, we have searched for lepton flavor violation in ep collisions at a center-of-mass energy (root s) of 300 GeV. Events of the type e + p --> l + X with a final-state lepton of high transverse momentum, l = mu or tau, were sought. No evidence was found for lepton flavor violation in the combined 1993 and 1994 data samples, for which the integrated luminosities were 0.84 pb(-1) for e(-)p collisions and 2.94 pb(-1) for e(+)p collisions. Limits on coupling vs. mass are provided for leptoquarks and R-parity violating squarks, For flavor violating couplings of electromagnetic strength, we set 95% confidence level lower limits on leptoquark masses between 207 GeV and 272 GeV, depending on the leptoquark species and final-state lepton. For leptoquark,masses larger than 300 GeV, limits on flavor-changing couplings are determined, many of which supersede prior limits from rare decay processes. C1 ANDREWS UNIV, BERRIEN SPRINGS, MI USA. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BONN, INST PHYS, D-53115 BONN, GERMANY. UNIV BRISTOL, HH WILLS PHYS LAB, BRISTOL B58 1TL, AVON, ENGLAND. UNIV CALABRIA, DEPT PHYS, I-87036 COSENZA, ITALY. IST NAZL FIS NUCL, COSENZA, ITALY. COLUMBIA UNIV, NEVIS LABS, IRVING ON HUDSON, NY 10533 USA. INST NUCL PHYS, PL-30055 KRAKOW, POLAND. ACAD MIN & MET, FAC PHYS & NUCL TECH, PL-30055 KRAKOW, POLAND. JAGIELLONIAN UNIV, DEPT PHYS, PL-30059 KRAKOW, POLAND. DESY, DEUTSCH ELEKTRON SYNCHROTRON, D-22603 HAMBURG, GERMANY. DESY, IFH ZEUTHEN, D-15738 ZEUTHEN, GERMANY. UNIV FLORENCE, FLORENCE, ITALY. IST NAZL FIS NUCL, I-50125 FLORENCE, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV FREIBURG, FAK PHYS, D-79104 FREIBURG, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW G12 8QQ, LANARK, SCOTLAND. UNIV HAMBURG, INST EXPT PHYS 1, D-22761 HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 2, D-22761 HAMBURG, GERMANY. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, HIGH ENERGY NUCL PHYS GRP, LONDON SW7 2BZ, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST KERNPHYS, D-52405 JULICH, GERMANY. KOREA UNIV, SEOUL 136701, SOUTH KOREA. LOUISIANA STATE UNIV, DEPT PHYS & ASTRON, BATON ROUGE, LA 70803 USA. UNIV AUTONOMA MADRID, DEPT FIS TEOR, E-28049 MADRID, SPAIN. MCGILL UNIV, DEPT PHYS, MONTREAL, PQ H3A 2T8, CANADA. MEIJI GAKUIN UNIV, FAC GEN EDUC, YOKOHAMA, KANAGAWA 244, JAPAN. MOSCOW ENGN PHYS INST, RU-115409 MOSCOW, RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, RU-119899 MOSCOW, RUSSIA. NIKHEF, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1009 DB AMSTERDAM, NETHERLANDS. OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. UNIV OXFORD, DEPT PHYS, OXFORD, ENGLAND. UNIV PADUA, DIPARTIMENTO FIS, I-35131 PADUA, ITALY. IST NAZL FIS NUCL, I-35131 PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIVERSITY PK, PA 16802 USA. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. IST NAZL FIS NUCL, I-00185 ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 93106 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, D-57012 SIEGEN, GERMANY. TEL AVIV UNIV, SCH PHYS, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, INST NUCL STUDY, TOKYO 113, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO 19203, JAPAN. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, I-10129 TURIN, ITALY. IST NAZL FIS NUCL, I-10129 TURIN, ITALY. TORINO UNIV, FAC SCI 2, ALESSANDRIA, ITALY. IST NAZL FIS NUCL, ALESSANDRIA, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO, ON M5S 1A7, CANADA. UNIV LONDON UNIV COLL, DEPT PHYS & ASTRON, LONDON WC1E 6BT, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, DEPT PHYS, BLACKSBURG, VA 24061 USA. UNIV WARSAW, INST EXPT PHYS, PL-00681 WARSAW, POLAND. INST NUCL STUDIES, PL-00681 WARSAW, POLAND. WEIZMANN INST SCI, DEPT NUCL PHYS, IL-76100 REHOVOT, ISRAEL. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. YORK UNIV, DEPT PHYS, TORONTO, ON M3J 1P3, CANADA. RP Derrick, M (reprint author), ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RI Solomin, Anatoly/C-3072-2016; Graciani Diaz, Ricardo/I-5152-2016; Capua, Marcella/A-8549-2015; Bashkirov, Vladimir/A-4818-2008; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; Morandin, Mauro/A-3308-2016; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Doyle, Anthony/C-5889-2009; Golubkov, Yury/E-1643-2012; Proskuryakov, Alexander/J-6166-2012; Katz, Uli/E-1925-2013; Wiggers, Leo/B-5218-2015; Hernandez Calama, Jose Maria/H-9127-2015 OI Graciani Diaz, Ricardo/0000-0001-7166-5198; Castellini, Guido/0000-0002-0177-0643; Capua, Marcella/0000-0002-2443-6525; Lancaster, Mark/0000-0002-8872-7292; Utley, Martin/0000-0001-9928-1516; Gladilin, Leonid/0000-0001-9422-8636; Morandin, Mauro/0000-0003-4708-4240; De Pasquale, Salvatore/0000-0001-9236-0748; Doyle, Anthony/0000-0001-6322-6195; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547 NR 49 TC 20 Z9 20 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0170-9739 J9 Z PHYS C PART FIELDS JI Z. Phys. C-Part. Fields PD MAR PY 1997 VL 73 IS 4 BP 613 EP 628 DI 10.1007/s002880050352 PG 16 WC Physics, Particles & Fields SC Physics GA WQ464 UT WOS:A1997WQ46400005 ER PT J AU Pitsillides, KF Rendig, SV Longhurst, JC AF Pitsillides, KF Rendig, SV Longhurst, JC TI Measurement of absolute myocardial function in small animals with a 20 MHz single-transducer sonomicrometer. SO FASEB JOURNAL LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DIV CARDIOVASC MED,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 411 EP 411 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53000411 ER PT J AU Symons, JD Martin, L Schaefer, S AF Symons, JD Martin, L Schaefer, S TI Na+/H+ exchange inhibition (NHEi) attenuates myocardial dysfunction of of short-term hibernation in swine. SO FASEB JOURNAL LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 431 EP 431 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53000433 ER PT J AU Xue, B Wilkinson, WO Mynatt, RL Moustaid, N Zemel, MB AF Xue, B Wilkinson, WO Mynatt, RL Moustaid, N Zemel, MB TI The agouti gene product stimulates pancreatic beta cell Ca2+ signaling and insulin release. SO FASEB JOURNAL LA English DT Meeting Abstract C1 UNIV TENNESSEE,KNOXVILLE,TN 37996. GLAXO WELLCOME INC,RES TRIANGLE PK,NC 27709. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 1338 EP 1338 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53001338 ER PT J AU Griffin, GD Miller, EJ Gailey, PC AF Griffin, GD Miller, EJ Gailey, PC TI Action of dehydroepiandrosterone (DHEA) on the estrogen response system in human brest cancer cells. SO FASEB JOURNAL LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 0 TC 0 Z9 0 U1 0 U2 1 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 1832 EP 1832 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53001834 ER PT J AU BurtonFreeman, B Davis, PA Schneeman, BO AF BurtonFreeman, B Davis, PA Schneeman, BO TI Dairy products as dietary fat sources: Effects on postprandial glucose and insulin SO FASEB JOURNAL LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DEPT NUTR,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DEPT INTERNAL MED,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 2157 EP 2157 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53002157 ER PT J AU Fountos, G Kounadi, E Tzaphlidou, M Glaros, D Yasumura, S AF Fountos, G Kounadi, E Tzaphlidou, M Glaros, D Yasumura, S TI Changes in the skeletal Ca/P ratio and collagen morphology in rabbits fed a diet low in Ca, P, and vitamin D, or made osteopenic by inflammation. SO FASEB JOURNAL LA English DT Meeting Abstract C1 UNIV IOANNINA,SCH MED,DEPT MED PHYS,GR-45110 IOANNINA,GREECE. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. NR 0 TC 1 Z9 1 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 2240 EP 2240 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53002239 ER PT J AU Yu, DY Lee, TY Kim, YU Jeong, SK Jeong, BH Lee, KK Lonnerdal, B AF Yu, DY Lee, TY Kim, YU Jeong, SK Jeong, BH Lee, KK Lonnerdal, B TI Expression of human alpha-S1-casein in human milk epithelial cells and E-coli. SO FASEB JOURNAL LA English DT Meeting Abstract C1 KIST,RES INST BIOSCI & BIOTECHNOL,TAEJON 305333,SOUTH KOREA. LAWRENCE LIVERMORE NATL LAB,DEPT NUTR,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 2283 EP 2283 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53002281 ER PT J AU McCrory, MA NommsenRivers, LA Mole, PA Lonnerdal, B Dewey, KG AF McCrory, MA NommsenRivers, LA Mole, PA Lonnerdal, B Dewey, KG TI A randomized trial of the effects of dieting vs dieting with exercise on lactation performance. SO FASEB JOURNAL LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DEPT NUTR,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 2289 EP 2289 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53002287 ER PT J AU Barger, LK HobanHiggins, TM Fuller, CA AF Barger, LK HobanHiggins, TM Fuller, CA TI Effects of lighting conditions on circadian rhythms of performance and drinking in rhesus monkeys. SO FASEB JOURNAL LA English DT Meeting Abstract C1 LAWRENCE LIVERMORE NATL LAB,DAVIS,CA 95616. NR 0 TC 0 Z9 0 U1 0 U2 0 PU FEDERATION AMER SOC EXP BIOL PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 USA SN 0892-6638 J9 FASEB J JI Faseb J. PD FEB 28 PY 1997 VL 11 IS 3 BP 3667 EP 3667 PG 1 WC Biochemistry & Molecular Biology; Biology; Cell Biology SC Biochemistry & Molecular Biology; Life Sciences & Biomedicine - Other Topics; Cell Biology GA WL530 UT WOS:A1997WL53003669 ER PT J AU Reissner, K Prior, A Wolfgang, J Bart, HJ Byers, CH AF Reissner, K Prior, A Wolfgang, J Bart, HJ Byers, CH TI Preparative desalting of bovine serum albumin by continuous annular chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 20th International Symposium on High Performance Liquid Phase Separations and Related Techniques CY JUN 16-21, 1996 CL SAN FRANCISCO, CA DE desalting methods; annular chromatography; preparative chromatography; proteins; albumin ID CONTINUOUS SEPARATIONS; PROTEINS AB Bovine serum albumin (BSA) was continuously desalted from alkaline salts (a mixture of sodium phosphate, sodium chloride and potassium chloride) using a size-exclusion gel as the stationary phase. An annular chromatograph was used to achieve a continuous mode of operation and therefore a reasonable throughput. Distribution and mass transfer coefficients of the substances as well as bed properties were obtained by batch chromatography. These separations were simulated mathematically applying an approximate linear chromatographic theory. It was shown experimentally and theoretically that the BSA and the salt solution could be recovered continuously in a purity higher than 98%. The influence of rotation rate on the resolution of the individual peaks was investigated. C1 UNIV KAISERSLAUTERN,DEPT CHEM ENGN,D-67653 KAISERSLAUTERN,GERMANY. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. PRIOR TECHNOL,VWP 6840,GOTZIS,AUSTRIA. NR 18 TC 16 Z9 16 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD FEB 28 PY 1997 VL 763 IS 1-2 BP 49 EP 56 DI 10.1016/S0021-9673(96)01001-1 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WT455 UT WOS:A1997WT45500005 PM 9129314 ER PT J AU Knize, MG Salmon, CP Hopmans, EC Felton, JS AF Knize, MG Salmon, CP Hopmans, EC Felton, JS TI Analysis of foods for heterocyclic aromatic amine carcinogens by solid-phase extraction and high-performance liquid chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 20th International Symposium on High Performance Liquid Phase Separations and Related Techniques CY JUN 16-21, 1996 CL SAN FRANCISCO, CA DE food analysis; aromatic amines, heterocyclic; amines ID BEEF EXTRACT; COOKED-FOOD; PRODUCTS; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE; MUTAGEN; MEAT; IDENTIFICATION; PHIP AB Carcinogenic and mutagenic heterocyclic aromatic amines (HAA) are natural products often present at ng/g levels in muscle meats when they are cooked at temperatures over 150 degrees C. Using solid-phase extraction and high performance liquid chromatography (HPLC) with photodiode array UV detection, samples were analyzed for the following heterocyclic amines: DiMeIQx (2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline); IQ (2-amino-3-methylimidazo[4,5-f]quinoline); MeIQx (2-amino-3 ,8-dimethylimidazo[4,5-f]quinoxaline); and PhIP (2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine). Quality control samples, analyzed periodically over two years in a blind study, show relative standard deviations ranging from 22 to 38% for the compounds found, variations typical for analysis at ng/g levels. Amounts range from undetectable levels (less than 0.1 ng/g) to hundreds of ng/g of PhIP for frying or grilling at high meat surface temperatures. Beef, chicken, pork and lamb can all have greater than 10 ng/g of PhIP. Ground chicken breast meat has lower amounts of heterocyclic amines than intact muscle pieces of the same size cooked identically. Restaurant prepared samples that we analyzed contained undetectable levels up to 14 ng/g total heterocyclic amines for a beef steak sample. Not extracted with the above method are related mutagenic heterocyclic amines, which have been reported in cooked foods in our laboratory and others. Method development using ion exchange on an SCX solid-phase extraction cartridge shows promise in providing a method for the quantitation of these mutagenic dimethyl-, trimethyl- and furo-imidazopyridines where a practical analysis method is needed. RP Knize, MG (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,L452,LIVERMORE,CA 94550, USA. FU NCI NIH HHS [CA55861, YO1CP2-0523-01] NR 26 TC 78 Z9 80 U1 0 U2 7 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 FEB 28 PY 1997 VL 763 IS 1-2 BP 179 EP 185 DI 10.1016/S0021-9673(96)00720-0 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WT455 UT WOS:A1997WT45500018 PM 9129321 ER PT J AU Berkowitz, J AF Berkowitz, J TI Sum rules and the oscillator strength distribution in helium SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID RESONANCE LINES; RARE-GASES; DOUBLE PHOTOIONIZATION; SELF-ABSORPTION; CROSS-SECTIONS; ENERGIES; TRANSITIONS; IONIZATION; RADIATION; ATTENUATION AB Recent experimental measurements and calculated photoabsorption cross sections for helium encompassing the discrete spectrum and continuum are tested by the sum rules S(p), p = -2, -1, 0, +1, +2. The agreement is excellent for S(-2), but degrades monotonically toward S(+2). For the latter, calculated cross sections are shown to be distinctly superior to recent experimentally derived values. The comparison of cross sections with sum rule values suggests that higher-order corrections to the latter may be useful. RP Berkowitz, J (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 47 TC 16 Z9 16 U1 1 U2 5 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 28 PY 1997 VL 30 IS 4 BP 881 EP 892 DI 10.1088/0953-4075/30/4/010 PG 12 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WM293 UT WOS:A1997WM29300010 ER PT J AU Stutman, D Finkenthal, M AF Stutman, D Finkenthal, M TI Investigation of the low-inductance vacuum spark as a source of soft x-ray atomic quasi-continua for optical pumping SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID LASER-PRODUCED PLASMAS; 4D-4F EMISSION RESONANCES; TRANSITION ARRAYS; ELECTRON-DENSITY; LINE EMISSION; SPECTRA; TOKAMAK AB A simplified radiative collapse model has been applied to a high-Z (Ce) low-inductance vacuum spark plasma, in order to assess the possibility of using this simple discharge to generate N-shell atomic quasi-continua for optical pumping of soft x-ray lasers. The radiative losses of the complex Ce ions are computed using statistical methods developed for unresolved transition arrays, and atomic data from the average ion model. The calculations predict that at sufficiently high current, a radiative collapse followed by micropinching takes place at the opening of the M-shell, in good agreement with experimental observations. The model predicts that the radiative losses associated with the quasi-continuum emission allow the plasma to be compressed to relatively high density prior to the micropinch. Nevertheless, despite this 'mild' radiative collapse, the average quasi-continuum brightness is below that required for optical pumping. Scaling the results to discharge currents shows this limitation to be intrinsic to Z-pinch type discharges. C1 HEBREW UNIV JERUSALEM,RACAH INST PHYS,IL-91904 JERUSALEM,ISRAEL. RP Stutman, D (reprint author), PRINCETON UNIV,PRINCETON PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. RI Stutman, Dan/P-4048-2015 NR 29 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 28 PY 1997 VL 30 IS 4 BP 951 EP 961 DI 10.1088/0953-4075/30/4/015 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WM293 UT WOS:A1997WM29300015 ER PT J AU Fiore, M Patel, SN Alleva, E Aloe, L Clayton, NS AF Fiore, M Patel, SN Alleva, E Aloe, L Clayton, NS TI Nerve growth factor effects on the song control system of zebra finches SO NEUROSCIENCE LETTERS LA English DT Article DE nerve growth factor; ibotenic acid; zebra finch; higher vocal center; cholinergic system; song; ChAT ID IBOTENIC ACID; CHOLINE-ACETYLTRANSFERASE; LESIONS; RATS; NUCLEUS; NEURONS; BIRDS AB The aim of this experiment was to test whether or not nerve growth factor (NGF) is involved in cholinergic processes in the avian brain, by injecting NGF into the higher vocal center (HVC) and examining its effects on adult male zebra finch song. Since NGF has been hypothesized to protect cells after injury, some birds received both NGF and ibotenic acid (IBO) lesions of HVC, while others received either NGF or IBO or neither (SHAM). Only the IBO-treated birds showed alterations in song. Although there was no evidence of cell preservation in the immunocytochemical and morphological analysis NGF appears to prevent the IBO induced impairment in song augmenting the activity of the remaining neurons and enhancing brain repair. (C) 1997 Elsevier Science Ireland Ltd. C1 CNR,INST NEUROBIOL,I-00137 ROME,ITALY. LAWRENCE LIVERMORE NATL LAB,DIV BIOL SCI,SECT NEUROBIOL PHYSIOL & BEHAV,DAVIS,CA 95616. UNIV OXFORD,DEPT ZOOL,OXFORD OX1 3PS,ENGLAND. IST SUPER SANITA,FOS,BEHAV PATHOPHYSIOL SECT,I-00161 ROME,ITALY. RI Clayton, Nicola/A-2891-2010; Alleva, Enrico/B-1630-2013; Fiore, Marco/B-6112-2015; OI fiore, marco/0000-0001-6806-9715 NR 22 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3940 J9 NEUROSCI LETT JI Neurosci. Lett. PD FEB 28 PY 1997 VL 223 IS 3 BP 161 EP 164 DI 10.1016/S0304-3940(97)13425-5 PG 4 WC Neurosciences SC Neurosciences & Neurology GA WM361 UT WOS:A1997WM36100006 PM 9080457 ER PT J AU Trilling, G AF Trilling, G TI LHC ''price tag'' SO SCIENCE LA English DT Letter RP Trilling, G (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,EXECUT COMM,BERKELEY,CA 94720, 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 FEB 28 PY 1997 VL 275 IS 5304 BP 1245 EP 1246 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WK644 UT WOS:A1997WK64400005 ER PT J AU Hauck, WW Bois, FY Hyslop, T Gee, L Anderson, S AF Hauck, WW Bois, FY Hyslop, T Gee, L Anderson, S TI A parametric approach to population bioequivalence SO STATISTICS IN MEDICINE LA English DT Article ID COMPARATIVE BIOAVAILABILITY; INDIVIDUAL BIOEQUIVALENCE; TESTING EQUIVALENCE; TRIALS; RATIO C1 LAWRENCE BERKELEY LAB,IEP,BERKELEY,CA 94720. UNIV CALIF SAN FRANCISCO,DIV BIOSTAT,SAN FRANCISCO,CA 94143. BRISTOL MYERS SQUIBB,BIOSTAT & DATA MANAGEMENT,PRINCETON,NJ 08543. RP Hauck, WW (reprint author), THOMAS JEFFERSON UNIV,DIV CHEM PHARMACOL,BIOSTAT SECT,125 S 9TH ST,SHERIDAN BLDG,SUITE 403,PHILADELPHIA,PA 19107, USA. RI Bois, Frederic/E-9241-2012 OI Bois, Frederic/0000-0002-4154-0391 FU NHLBI NIH HHS [HL51401] NR 18 TC 13 Z9 13 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0277-6715 J9 STAT MED JI Stat. Med. PD FEB 28 PY 1997 VL 16 IS 4 BP 441 EP 454 DI 10.1002/(SICI)1097-0258(19970228)16:4<441::AID-SIM390>3.3.CO;2-6 PG 14 WC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Medicine, Research & Experimental; Statistics & Probability SC Mathematical & Computational Biology; Public, Environmental & Occupational Health; Medical Informatics; Research & Experimental Medicine; Mathematics GA WK019 UT WOS:A1997WK01900009 PM 9044531 ER PT J AU Parakka, JP Kini, AM Williams, JM AF Parakka, JP Kini, AM Williams, JM TI Convenient synthesis of bis(benzo)-fused BEDT-TTF and higher homologues New electron donor molecules for organic charge transfer salts and ''molecular rulers'' SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE organic superconductors; molecular rulers; BEDT-TTF or ET derivatives; heterocycle synthesis; coupling reactions ID SUPERCONDUCTORS AB A convenient synthesis of bis(benzo)- and bis(naphtho)-fused bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) derivatives,employing the [4+2] cycloaddition reaction of oligo(1,3-dithiole-2,4,5-trithione) with appropriate alkenes as a key step, is presented. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Parakka, JP (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Kini, Aravinda/F-4467-2012 NR 11 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 1805 EP 1806 DI 10.1016/S0379-6779(97)80912-5 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800010 ER PT J AU Li, DQ Yang, XG McBranch, D AF Li, DQ Yang, XG McBranch, D TI Molecular architecture of calixarenes and their self-assembled mono- and multi-layers for nonlinear optical (NLO) applications SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE self-assembly using surface chemistry; self-organization in macromolecules; non-linear optical methods; all-optical modulator; organic/inorganic interfaces; and lasers AB The synthesis and characterization of supermolecular chromophore-calix[4]stilbazole were described. The calix [4] arene-based, chromophore forms densely packed, highly ordered monolayers on silica surfaces. Ultra-high second order nonlinearities were observed in these systems, and spectroscopic second harmonic generation was used to characterize the frequency dispersion of the second order susceptibilities. RP Li, DQ (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545, USA. NR 5 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 1849 EP 1850 DI 10.1016/S0379-6779(97)80934-4 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800032 ER PT J AU Strouse, GF Scott, B Berkey, M Johnson, S Darling, T Migliori, A Swanson, BI AF Strouse, GF Scott, B Berkey, M Johnson, S Darling, T Migliori, A Swanson, BI TI Coulomb driven chain ordering phase transitions in the quasi-1-D electronic material d8-PtI/en/ClO4 SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE infrared and Raman spectroscopy; order-disorder phase transitions ID RAMAN-SPECTRA; SOLIDS; COMPLEXES; CRYSTAL AB The MX material [Pt(en)(2)I-2][Pt(en)(2)](ClO4)(4), where en is per-deuterated ethylenediamine, represents a new structural type for the MX family. The material, which crystallizes in the C-2/m monoclinic space group, forms sheets of ordered and disordered 1-D chains and exhibits two phase transitions at 160K and similar to 120K. By comparison of the crystallographic, vibrational, and acoustic data the transition at 160K can be attributed to c-axis doubling with ordering of the en groups in the disordered sheet and formation of an acentric, C-2 crystal. The phase transition is driven by hydrogen bonding in the disordered sheet. The structural transition at similar to 120K is a discommensurate to commensurate phase transition in the sheets of disordered chains. The phase transition is driven by coloumbic ordering of the chains in the disordered sheet. Resonant ultrasound and thermal data suggest that both transitions are second or higher order and Raman data suggest ordering of the en's of the ordered chain below 120K. RP Strouse, GF (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 14 TC 4 Z9 4 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 1919 EP 1922 DI 10.1016/S0379-6779(97)80964-2 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800066 ER PT J AU Kanner, GS Strouse, GF Swanson, BI AF Kanner, GS Strouse, GF Swanson, BI TI Excitation dependence of the subpicosecond dynamics of excitons and polarons in the MX chain solid PtCl SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE laser spectroscopy; time-resolved fast spectroscopy; photoinduced absorption spectroscopy ID RESONANCE RAMAN; RELAXATION; POLYDIACETYLENE; LUMINESCENCE; ABSORPTION AB We have measured the subpicosecond photoinduced absorption for the MX chain solid PtCl. For excitation into the tail of the exciton absorption a state is generated with a lifetime of 100-200 ps, and is associated with the lowest even parity exciton. For lower energy pump, our results are consistent with excitation of intrinsic polarons, which decay to the ground state in about 1 ps. Excitation well above the exciton band edge may result in the formation of polarons and excitons. RP Kanner, GS (reprint author), LOS ALAMOS NATL LAB,CST-1,MS G755,LOS ALAMOS,NM 87545, USA. NR 11 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 1929 EP 1930 DI 10.1016/S0379-6779(97)80967-8 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800069 ER PT J AU Eldridge, JE Xie, Y Lin, Y Wang, HH Williams, JM Schlueter, JA AF Eldridge, JE Xie, Y Lin, Y Wang, HH Williams, JM Schlueter, JA TI Resonant Raman scattering and electron-phonon coupling in the organic superconductor (BEDT-TTF)(2)[Cu(NCS)(2)] SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE infrared and Raman spectroscopy; organic superconductors AB The frequency shifts of the Ag modes, which appear in the infrared conductivity of x-(ET)(2)[Cu(NCS)(2)], are due to electron-phonon coupling and have been measured by comparing the infrared spectrum with the resonant Raman spectrum obtained with an infrared laser. The agreement with calculated values is very good. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Eldridge, JE (reprint author), UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER,BC V67 1Z1,CANADA. NR 4 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2067 EP 2068 DI 10.1016/S0379-6779(97)81030-2 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800132 ER PT J AU Bracewell, BL Scott, BL Berkey, M Swanson, BI AF Bracewell, BL Scott, BL Berkey, M Swanson, BI TI Structural evolution of the charge-density-wave strength in PtI/chxn/I as a function of temperature and pressure SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE charge-density-wave strength AB We report the X-ray crystal and molecular structure of the extremely weak CDW system [Pt(chxn)(2)I-2][Pt(chxn)(2)]I-4 at 298 K and 123 K. The temperature and pressure dependent resonance Raman are also presented. It is shown that increasing pressure and decreasing temperature drive the MX chain to a stronger CDW, in contrast to most MX systems. A structural explanation is given. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. RP Bracewell, BL (reprint author), UNIV COLORADO,DEPT PHYS,COLORADO SPRINGS,CO 80907, USA. RI Scott, Brian/D-8995-2017 OI Scott, Brian/0000-0003-0468-5396 NR 3 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2097 EP 2098 DI 10.1016/S0379-6779(97)81045-4 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800147 ER PT J AU Darling, TW Migliori, A Strouse, G Swanson, B Johnson, S Hundley, MF Thompson, JD AF Darling, TW Migliori, A Strouse, G Swanson, B Johnson, S Hundley, MF Thompson, JD TI Resonant ultrasound spectroscopy and comparative studies of a 1-D linear chain (MX) material SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE ultrasound; phase transitions AB Resonant Ultrasound Spectroscopy (RUS) is a measurement technique which utilizes the natural resonance frequencies of a body to determine elastic properties. It may be applied to small (similar to mm) samples and measurements can be made over a wide range of temperatures and magnetic fields. If the geometry of the sample is well known we can determine absolute values of elastic moduli for crystals of up to orthorhombic symmetry (9 constants). We have applied RUS to single crystals of the MX material [Pt(en)(2)I-2][Pt(en)(2)](ClO4)(4), where(en) is per-deuterated ethylenediamine. We have observed several anomalies in the behavior of the resonances with temperature which may be associated with phase transitions in the material. RP Darling, TW (reprint author), LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545, USA. RI CHEN, Jiangang/A-1549-2011 NR 3 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2153 EP 2154 DI 10.1016/S0379-6779(97)81072-7 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800175 ER PT J AU Bishop, AR AF Bishop, AR TI Tuning ground states and excitations in complex electronic materials SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE broken symmetries; nonlinearity; spin-charge-lattice coupling, breathers, polarons ID PEIERLS-HUBBARD MODEL; SPIN; YBA2CU3O7 AB Modern electronic materials are characterized by a great variety of broken-symmetry ground states and excitations. Their control requires understanding and tuning underlying driving forces of spin-charge-lattice coupling, critical to macroscopic properties and applications. We report representative model calculations which demonstrate some of the richness of the phenomena and the challenges for successful microscopic modeling. RP Bishop, AR (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 20 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2203 EP 2209 DI 10.1016/S0379-6779(97)81096-X PG 7 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800199 ER PT J AU Roder, H Bishop, AR Gammel, JT AF Roder, H Bishop, AR Gammel, JT TI Tunability of crossover phases in MX-compounds SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE crossover phases ID TRANSITION-METAL COMPLEXES; PEIERLS-HUBBARD MODEL; 2-BAND MODEL AB MX materials offer the unique opportunity to study a whole variety of phases from CDW phases over long-range mixed phases to SDW phases by changing the chemical composition, or by applying external pressure. Especially in the regime of the mixed, long wavelength phases, where the free energy differences are small, a magnetic field can be used to select a specific phase characterized by certain charge and spin correlations. We discuss the characteristics of those phases and their relevant parameters regimes and experimental signatures. Since the free energy differences between various phases are small we also discuss the influence of non-adiabaticity and disorder on their relative stability. RP Roder, H (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B221,LOS ALAMOS,NM 87545, USA. NR 12 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2211 EP 2213 DI 10.1016/S0379-6779(97)81097-1 PG 3 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800200 ER PT J AU Gammel, JT Wang, WZ Bishop, AR Salkola, MI AF Gammel, JT Wang, WZ Bishop, AR Salkola, MI TI Quantum breathers in nonlinear phonon and coupled electron-phonon systems SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE models of nonlinear phenomena; lattice dynamics; computer simulations AB Nonlinear quantum phonon excitations are studied in 1D lattice models for both effective nonlinear phonon and coupled electron-phonon systems. Multi-phonon bound states exist which are eigenstates of the system Hamiltonian, and which are natural counterparts of breather solutions of classical nonlinear systems. These quantum breather states form particle-like bands and are characterized by a finite coherence length. Due to their structure and dynamics, quantum breathers have specific experimentally observable responses in many correlation functions. In the pure phonon model, the dynamic structure factor is found to have significant intensity for the breather states, with a corresponding quenching of the neighboring bands of multi-phonon extended states. In the coupled electron-phonon model, IR and optical absorption spectra for breathers are reported. C1 CHINESE ACAD SCI, INST THEORET PHYS, BEIJING 100080, PEOPLES R CHINA. MCMASTER UNIV, DEPT PHYS & ASTRON, HAMILTON, ON L8S 4M1, CANADA. RP Gammel, JT (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 12 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2215 EP 2216 DI 10.1016/S0379-6779(97)81098-3 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800201 ER PT J AU Zang, J Roder, H Gammel, JT Saxena, A Bishop, AR AF Zang, J Roder, H Gammel, JT Saxena, A Bishop, AR TI Phonon effects in the two-magnon Raman scattering in spin-Peierls systems SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE lattice dynamics; many-body and quasiparticle theories; infrared and Raman spectroscopy ID CHAINS; CUGEO3 AB The phonon assisted Fleury-Loudon two-magnon scattering in spin-Peierls systems is derived and its effect on the scattering processes is studied. We find that the phonon effects are important for two-magnon Raman scattering in both dimerized and uniform phases. C1 LOS ALAMOS NATL LAB,CNLS,LOS ALAMOS,NM 87545. RP Zang, J (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B262,LOS ALAMOS,NM 87545, USA. NR 14 TC 0 Z9 0 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2227 EP 2228 DI 10.1016/S0379-6779(97)81104-6 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800207 ER PT J AU Saxena, A Shuai, Z Bredas, JL Bishop, AR AF Saxena, A Shuai, Z Bredas, JL Bishop, AR TI Nonlinear optical response of MX chains in a one-band extended Peierls-Hubbard model SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE models of non-linear phenomena; non-linear optical methods; electroabsorption ID BRIDGED MIXED-VALENCE; COMPLEXES; EXCITATION; SPECTRUM AB We study the nonlinear optical (NLO) response of quasi-one-dimensional electronic materials with both the electron-phonon and electron-electron interactions using a discrete, 1/2-filled, one-band, tight-binding extended Peierls-Hubbard model. Specifically, the variation of (i) photoinduced absorption, (ii) electroabsorption and (iii) third-order nonlinear optical susceptibility (chi((3))) as a function of electronic correlation (Hubbard parameters U,V) is studied systematically within single configuration intetaction (CI). These results are generic to low-dimensional materials such as conducting polymers. However, for relevant choice of parameters here we apply them to the case of MX chains. The predicted NLO response is compared with available experimental data on the strong charge-density-wave (CDW) MX material PtCl. C1 UNIV MONS, SERV CHIM MAT NOUVEAUX, B-7000 MONS, BELGIUM. RP LOS ALAMOS NATL LAB, DIV THEORET, MS B262, LOS ALAMOS, NM 87545 USA. RI Bredas, Jean-Luc/A-3431-2008; Shuai, Zhigang/H-5576-2011 OI Bredas, Jean-Luc/0000-0001-7278-4471; Shuai, Zhigang/0000-0003-3867-2331 NR 9 TC 2 Z9 2 U1 2 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2231 EP 2232 DI 10.1016/S0379-6779(97)81106-X PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800209 ER PT J AU Partee, J Shinar, J Lane, PA Wei, X Vardeny, ZV AF Partee, J Shinar, J Lane, PA Wei, X Vardeny, ZV TI Photoluminescence-detected magnetic resonance (PLDMR) studies of matrix isolated molecules and films of C-60 and C-70 SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE optically detected magnetic resonance; photoluminescence; polarons; excitons; C-60; C-70 ID PHOTOEXCITATIONS; GLASSES AB The X-band spin 1/2 photoluminescence-detected magnetic resonance (PLDMR) of C-60 and C-60 isolated in a toluene/polystyrene matrix and various films is reviewed. The fluorescence (F)-enhancing triplet resonances of the isolated molecules are attributed to ground-state repopulation by a nonradiative triplet state delocalized over the molecule. The phosphorescence-detected resonance of C-70 glasses is due to the direct radiative decay of the long-lived triplets. Its strong temperature dependence results apparently from a dynamic Jahn-Teller effect. The PLDMR of C-60 and C-70 films is similar, and includes a narrow F-enhancing spin 1/2 resonance (Delta H(1/2)similar to 8G) at g similar to 2.0025 and narrow and broad triplet patterns at full- and half-fields. The spill 1/2 resonance is discussed in relation to polaron recombination or a radical-triplet pair mechanism. The narrow triplet pattern attributed to a triplet delocalized over the molecule, is slightly narrower than in C-60, consistent with a slightly larger exciton. The broad pattern is similar to that observed in pi-conjugated polymers and is believed to result from a triplet localized oil a pentagon or hexagon adjacent to a neighboring molecule. C1 US DOE, AMES, IA 50011 USA. UNIV UTAH, DEPT PHYS, SALT LAKE CITY, UT 84112 USA. RP Partee, J (reprint author), IOWA STATE UNIV, DEPT PHYS & ASTRON, AMES, IA 50011 USA. NR 12 TC 0 Z9 0 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2305 EP 2306 DI 10.1016/S0379-6779(97)81136-8 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800239 ER PT J AU Wei, X Dick, D Jeglinski, SA Vardeny, ZV AF Wei, X Dick, D Jeglinski, SA Vardeny, ZV TI Quantum efficiency study of photoexcited states in fullerenes SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE fullerenes; photoluminescence; photoinduced absorption; electroabsorption; resonant Raman ID SOLID C-60; FILMS; C60; PHOTOCONDUCTIVITY; SPECTRA; TRANSITIONS; EXCITONS; CARBON; C-70; GAP AB We present a comparative study of photoluminescence (PL) and photoinduced absorption (PA) excitation spectroscopy, resonant Raman (RR) spectroscopy and electroabsorption (EA) of C-60 and C-70 from 1.5 eV to 4.5 eV. In C-60 solid-state films, a salient feature at 2.3 eV was observed, which manifests itself as a peak in the PL excitation and RR spectra, as an onset in the excitation spectra of charge carriers and triplet excitons, and as the first prominent derivative feature in the EA spectrum. In contrast, these features are absent in the case of isolated C-60 molecules. We attribute the 2.3 eV feature to a charge transfer state in solid C-60. A similar charge transfer state was also observed in solid C-70 at 2.15 eV. C1 UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112. RP Wei, X (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 26 TC 14 Z9 14 U1 1 U2 8 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2317 EP 2320 DI 10.1016/S0379-6779(97)81142-3 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800245 ER PT J AU Wang, WZ Wang, CL Bishop, AR Yu, L Su, ZB AF Wang, WZ Wang, CL Bishop, AR Yu, L Su, ZB TI Dynamic Jahn-Teller effect in fullerene C-60 and related observable effects SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE molecular dynamics; lattice dynamics; many-body and quasiparticle theories; models of non-linear phenomena; infrared and Raman spectroscopy; electron spin resonance; optically detected magnetic resonance ID ELECTRON-VIBRON INTERACTIONS; CHARGED FULLERENES; BERRY PHASES; C60; TRIPLET; ABSORPTION; MOLECULES; SPECTRA; ANION; STATE AB Based on the Bogoliubov-de Gennes formalism, the linear multi-mode T-1u circle times 8h(g) static Jahn-Teller problem is aanalyzed for the charged C-60(-), C-60(2-), the lowest triplet and singlet self-trapped exciton (STE) of C-60. The dynamic Jahn-Teller effect due to quantum tunneling between the six degenerate D-5d configurations is studied within a perturbation approach. The tunneling induced level splittings are determined to be T-2(1u) circle plus T-2(3u), (1)A(g) circle plus H-1(g), T-3(3g) circle plus T-3(1g) and T-1(3g) circle plus T-1(1g) for C-60(1-), C-60(2-), triplet and singlet STE's of neutral C-60, respectively. The observable consequences of the dynamic Jahn-Teller effect are considered. Some of the Jahn-Teller active (as well as Raman-active) modes are predicted to be observable as multi-phonon overtones in the infrared absorption. In the photo-induced multi-phonon resonant Raman scattering the tunnel splitting itself should show up in the Raman spectrum, and the depolarization ratio is sensitive to the exciting frequency. C1 CHINESE ACAD SCI,INST THEORET PHYS,BEIJING 100080,PEOPLES R CHINA. CHINA CTR ADV SCI & TECHNOL,BEIJING 100080,PEOPLES R CHINA. INT CTR THEORET PHYS,I-43100 TRIESTE,ITALY. RP Wang, WZ (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 34 TC 4 Z9 4 U1 3 U2 7 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 28 PY 1997 VL 86 IS 1-3 BP 2365 EP 2368 DI 10.1016/S0379-6779(97)81163-0 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WZ988 UT WOS:A1997WZ98800266 ER PT J AU Gosnell, TR AF Gosnell, TR TI Avalanche assisted upconversion in Pr3+/Yb3+-doped ZBLAN glass SO ELECTRONICS LETTERS LA English DT Article DE rare-earth doped fibres; fluoride glasses; upconversion ID FLUORIDE FIBER; MU-M; AMPLIFICATION; RED AB Thr author reports efficient upconversion optical pumping of the P-3 levels of Pr3+ in ZBLAN glass codoped with Yb3+. Measurements of Pr3+ visible emission against infrared pump intensity demonstrate thr existence of an avalanche pumping process which comprises three components: radiationless energy transfer from Yb3+ to Pr3+, excited-state absorption in Pr3+, and cross-relaxation between excited Pr3+ ions and ground-state Yb3+ ions. RP Gosnell, TR (reprint author), LOS ALAMOS NATL LAB,CONDENSED MATTER & THERMAL PHYS GRP,MAIL STOP E543,LOS ALAMOS,NM 87545, USA. NR 9 TC 37 Z9 37 U1 0 U2 4 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 FEB 27 PY 1997 VL 33 IS 5 BP 411 EP 413 DI 10.1049/el:19970220 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA WT998 UT WOS:A1997WT99800048 ER PT J AU Halthore, RN Eck, TF Holben, BN Markham, BL AF Halthore, RN Eck, TF Holben, BN Markham, BL TI Sun photometric measurements of atmospheric water vapor column abundance in the 940-nm band SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID PRECIPITABLE WATER; SOLAR TRANSMISSION AB Sun photometers operating in the strong water vapor absorption 940-nm combination-vibrational band have been used to determine water column abundance in the atmosphere when the path to the Sun is clear of clouds. We,describe a procedure to perform a rapid determination of the water column abundance, using sun photometers with an accuracy that is easily comparable to that of the radiosondes. The effect of parameters, such as filter bandwidth, atmospheric lapse rate, and the water vapor amount, on the accuracy of the retrieved abundance is examined. It is seen that a narrow filter band of approximately 10-nm bandwidth, positioned at the peak of absorption, is quite insensitive to the type of atmosphere present during calibration or measurement with less than 1% variability under extreme atmospheric conditions. A comparison of the retrieved water column abundance using sun photometers with contemporaneously measured values using radiosondes and microwave radiometers shows that the latest version of the radiative transfer algorithm used in this procedure, MODTRAN-3, gives far superior results in comparison with earlier versions because of the use of improved absorption coefficients in the 940-nm bands. Results from a network of sun photometers spread throughout the globe will be discussed. C1 HUGHES STX CORP, LANHAM, MD 20706 USA. NASA, GODDARD SPACE FLIGHT CTR, TERR PHYS LAB, GREENBELT, MD 20771 USA. RP Halthore, RN (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, BLDG 426, UPTON, NY 11973 USA. RI ECK, THOMAS/D-7407-2012; Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 21 TC 101 Z9 112 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-897X J9 J GEOPHYS RES-ATMOS JI J. Geophys. Res.-Atmos. PD FEB 27 PY 1997 VL 102 IS D4 BP 4343 EP 4352 DI 10.1029/96JD03247 PG 10 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WL278 UT WOS:A1997WL27800010 ER PT J AU Engelke, R Pettit, DR Sheffield, SA AF Engelke, R Pettit, DR Sheffield, SA TI Pressure driven ligand rearrangement reaction in a cobalt-chloride complex SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article AB We report experimental results concerning the occurrence and rate of the reaction CoCl2(EtOH)2 + 4EtOH --> Co(EtOH)(6)(2+) + 2Cl(-) induced by transient high pressure. The experimental probe used to interrogate the system was time-resolved visible light spectroscopy; The transient high pressures induced in the samples were produced by projectiles launched by a single-stage gas gun; consequently, the hydrodynamic flows experienced by the samples were well-defined. The pressures the test samples were subjected to were in the range 0.75-6.7 GPa. Ambient-pressure control experiments, in which the reaction was induced by altering sample temperature, are also reported. For a 20/80 wt % CoCl2 . 6H(2)O/EtOH solution, shocked to ca. 6.7 GPa, we observed the disappearance of signature spectrum of the CoCl2(EtOH)2 species and the appearance of the spectrum of the Co(EtOH)(6)(2+) structure. The cobalt structure on the left side of the equilibrium equation above is tetrahedral, while that on the right is octahedral. In shock-pressurized systems, we have observed the disappearance of the tetrahedral complex and found the time scale for this process is ca. 200 ns. Similarly, in other shock experiments, we have observed the appearance of the octahedral complex and found the time scale for this process is ca. 500 ns. The relevance of the present results to ideas concerning the character of ionic chemical reactions possibly important in detonating condensed-phase explosives is briefly discussed. RP Engelke, R (reprint author), LOS ALAMOS NATL LAB,MS P952,LOS ALAMOS,NM 87545, USA. NR 19 TC 8 Z9 8 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 FEB 27 PY 1997 VL 101 IS 9 BP 1696 EP 1704 DI 10.1021/jp9629405 PG 9 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL354 UT WOS:A1997WL35400010 ER PT J AU Teppen, BJ Rasmussen, K Bertsch, PM Miller, DM Schafer, L AF Teppen, BJ Rasmussen, K Bertsch, PM Miller, DM Schafer, L TI Molecular dynamics modeling of clay minerals .1. Gibbsite, kaolinite, pyrophyllite, and beidellite SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID AB-INITIO CALCULATIONS; ELECTRON-DENSITY DISTRIBUTION; MONTE-CARLO SIMULATIONS; COMPUTER-SIMULATION; CRYSTAL-STRUCTURE; FORCE-FIELDS; BASIS SET; WATER INTERFACE; SOLID INTERFACE; ORBITAL METHODS AB A molecular dynamics model for clays and the oxide minerals is desirable for studying the kinetics and thermodynamics of adsorption processes. To this end, a valence force field for aluminous, dioctahedral clay minerals was developed. Novel aspects of this development include the bending potential for octahedral 0-A1-0 angles, which uses a quartic polynomial to create a double-well potential with minima at both 90 degrees and 180 degrees. Also, atomic point charges were derived from comparisons of ab initio molecular electrostatic potentials with X-ray diffraction-based deformation electron densities. Isothermal-isobaric molecular dynamics simulations of quartz, gibbsite, kaolinite, and pyrophyllite were used to refine the potential energy parameters. The resultant force field reproduced all the major structural parameters of these minerals to within 1% of their experimentally determined values. Transferability of the force field to simulations of adsorption onto clay mineral surfaces was tested through simulations of Na+, Ca2+, and hexadecyltrimethylammonium (HDTMA(+)) in the interlayers of beidellite clays. The new force field worked rather well with independently derived nonbonded parameters for all three adsorbates, as indicated by comparisons between experimental and molecular-dynamics-predicted d((001)) layer spacings of the homoionic beidellites. C1 TECH UNIV DENMARK, DEPT CHEM, DK-2800 LYNGBY, DENMARK. UNIV ARKANSAS, DEPT AGRON, FAYETTEVILLE, AR 72701 USA. UNIV ARKANSAS, DEPT CHEM & BIOCHEM, FAYETTEVILLE, AR 72701 USA. RP Teppen, BJ (reprint author), UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, ADV ANALYT CTR ENVIRONM SCI, PO DRAWER E, AIKEN, SC 29802 USA. NR 96 TC 179 Z9 182 U1 4 U2 57 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 FEB 27 PY 1997 VL 101 IS 9 BP 1579 EP 1587 DI 10.1021/jp961577z PG 9 WC Chemistry, Physical SC Chemistry GA WL357 UT WOS:A1997WL35700015 ER PT J AU Jentzen, W Song, XZ Shelnutt, JA AF Jentzen, W Song, XZ Shelnutt, JA TI Structural characterization of synthetic and protein-bound porphyrins in terms of the lowest-frequency normal coordinates of the macrocycle SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Review ID NONPLANAR NICKEL(II) PORPHYRINS; LIGHT-ABSORPTION PROPERTIES; RESONANCE RAMAN-SPECTRA; CYTOCHROME-C; MOLECULAR-STRUCTURE; CRYSTAL-STRUCTURE; X-RAY; PHOTOSYNTHETIC CHROMOPHORES; CONFORMATION CHANGE; FERRICYTOCHROME-C AB The X-ray crystal structures of synthetic and protein-bound metalloporphyrins are analyzed using a new normal structural decomposition method for classifying and quantifying their out-of-plane and in-plane distortions. These distortions are characterized in terms of equivalent displacements along the normal coordinates of the D-4h-symmetric porphyrin macrocycle (normal deformations) by using a computational procedure developed for this purpose. Often it turns out that the macrocyclic structure is, even in highly distorted porphyrins, accurately represented by displacements along only the lowest-frequency normal coordinates. Accordingly, the macrocyclic structure obtained from just the out-of-plane normal deformations of the saddling (sad, B-2u)-, ruffling (ruf, B-1u)-, doming (dom, A(2u))-, waving [wav(x), wav(y); E(g)]-, and propellering (pro, A(1u))-type essentially simulates the out-of-plane distortion of the X-ray crystal structure. Similarly, the observed inplane distortions are decomposed into in-plane normal deformations corresponding to the lowest-frequency vibrational modes including macrocycle stretching in the direction of the meso-carbon atoms (meso-str, B-2g), stretching in the direction of the nitrogen atoms (N-str, B-1g), x and y pyrrole translations [trn(x), trn(y); E(u)], macrocycle breathing (bre, A(1g)), and pyrrole rotation (rot, A(2g)) The finding that the displacements of the 24 atoms of the macrocycle primarily occur along the lowest-frequency normal coordinates is expected on physical grounds and is verified by structural decomposition of more than 100 synthetic and 150 protein-bound metalloporphyrin X-ray crystal structures. Because of the high resolution of the X-ray crystal structures of synthetic metalloporphyrins, the small displacements for other normal coordinates are also able to be discerned. However, for the heme groups in proteins, only the displacements along the lowest-frequency modes are detectable because of the large uncertainties in the atomic positions. The heme groups in the four X-ray crystal structures of deoxyhemoglobin are used to evaluate the structural decomposition method. We find that the corresponding heme groups in different X-ray crystal structures are similar. Furthermore, the out-of-plane distortions for the heme groups in the alpha- and beta-chains are found-to be inequivalent, that is, the two alpha-heme groups are mainly ruffled and domed whereas the two beta-heme groups are primarily saddled and domed. In the case of isozyme-1 ferrocytochrome c and its mutants, the heme distortion is not significantly influenced by the point mutations, and the strongly nonplanar structure is most likely the result of interactions of the heme group with a small protein segment, probably the Linkage Cys-Leu-Gln-Cys-His. This conclusion is in agreement with previous findings that the heme distortion in cytochrome is conserved for the proteins for which X-ray crystal structures exist and significant structural variation occurs only when an amino acid difference appears in Cys-X-Y-Cys-His segment. A similar conclusion is suggested by the structural decomposition results of the four heme groups in cytochromes c(3). The analogous covalently linked peptide segments vary for each heme group, giving different distortions for the four hemes. Nevertheless, the distinctive distortion of each heme group is conserved for cytochromes cs from different species as long as the short peptide sequences between the cysteine linkages are homologous. C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. RP Jentzen, W (reprint author), SANDIA NATL LABS,CATALYSIS & CHEM TECHNOL DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Shelnutt, John/A-9987-2009 OI Shelnutt, John/0000-0001-7368-582X NR 102 TC 258 Z9 259 U1 4 U2 26 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 FEB 27 PY 1997 VL 101 IS 9 BP 1684 EP 1699 DI 10.1021/jp963142h PG 16 WC Chemistry, Physical SC Chemistry GA WL357 UT WOS:A1997WL35700029 ER PT J AU Csoto, A AF Csoto, A TI Off-shell effects in the energy dependence of the Be-7(p,gamma)B-8 astrophysical S factor SO PHYSICS LETTERS B LA English DT Article DE Be-7(p,gamma)B-8; solar neutrinos; radiative capture; Coulomb dissociation; astrophysical S factor ID GAMMA)B-8 CROSS-SECTION; SOLAR-NEUTRINO PROBLEM; COULOMB DISSOCIATION; B-8; BE-7(P; NUCLEI; MODEL AB I show that off-shell effects, like antisymmetrization and Be-7 distortions, can significantly influence the energy dependence of the nonresonant Be-7(p, gamma)B-8 astrophysical S factor at higher energies. The proper treatment of these effects results in a virtually flat El component of the S factor at E(cm) = 0.3 - 1.5 MeV energies in the present eight-body model. The energy dependence of the nonresonant S factor, predicted by the present model, is in agreement with the low-energy radiative capture data and the existing high-energy Coulomb dissociation data. Irrespective of whether or not the present energy dependence is correct, off-shell effects can cause 15-20% changes in the value of S(0) extrapolated from high-energy(E(cm) > 0.7 MeV) data. C1 CALTECH, WK KELLOGG RADIAT LAB, PASADENA, CA 91125 USA. MICHIGAN STATE UNIV, NATL SUPERCONDUCTING CYCLOTRON LAB, E LANSING, MI 48824 USA. RP LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 52 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 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD FEB 27 PY 1997 VL 394 IS 3-4 BP 247 EP 252 DI 10.1016/S0370-2693(97)00031-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL502 UT WOS:A1997WL50200004 ER PT J AU Ohnishi, A Randrup, J AF Ohnishi, A Randrup, J TI Quantum fluctuation effects on nuclear fragment formation SO PHYSICS LETTERS B LA English DT Article ID HEAVY-ION COLLISIONS; FERMIONIC MOLECULAR-DYNAMICS; ANTISYMMETRIZED VERSION; 2-NUCLEON COLLISIONS; MULTIFRAGMENTATION; EQUATION; FUSION; SYSTEM; MATTER; STATE AB Multifragmentation in Au+Au collisions is investigated at incident energies in the range 100-400 MeV per nucleon by means of a recently developed quantal Langevin model. The inclusion of quantum fluctuations enhances the average multiplicity of intermediate mass fragments, especially in central collisions. This is mainly because the excitation energies of fragments are reduced due to the quantal behavior of intrinsic specific heat. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. 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 33 TC 22 Z9 22 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 FEB 27 PY 1997 VL 394 IS 3-4 BP 260 EP 268 DI 10.1016/S0370-2693(97)00032-4 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WL502 UT WOS:A1997WL50200006 ER PT J AU ChangLiu, CM Woloschak, GE AF ChangLiu, CM Woloschak, GE TI Effect of passage number on cellular response to DNA-damaging agents: Cell survival and gene expression SO CANCER LETTERS LA English DT Article DE DNA damage; gene expression; oncogene activation; cell culture; radiation ID NUCLEAR ANTIGEN CYCLIN; LOW-LET RADIATIONS; PROTEIN-KINASE-C; IONIZING-RADIATION; CYTOSKELETAL ELEMENTS; MESSENGER-RNA; MODULATION; EXPOSURE; VIRUS; IDENTIFICATION AB The effect of different passage numbers on plating efficiency, doubling time, cell growth, and radiation sensitivity was assessed in Syrian hamster embryo (SHE) cells. Changes in gene expression after UV or gamma-ray irradiation at different passage numbers were also examined. The SHE cells were maintained in culture medium for up to 64 passages. Cells were exposed to Co-60 gamma rays or 254-nm UV radiation. Differential display of cDNAs and Northern blots were used for the study of gene expression. With increasing passage number, SHE cells demonstrated decreased doubling time, increased plating efficiency, and a decreased yield in the number of cells per plate. Between passages 41 and 48 a 'crisis' period was evident during which time cell growth in high serum (20%) was no longer optimal, and serum concentrations were reduced (to 10%) to maintain cell growth. Sensitivity to ionizing radiation was no different between early- and intermediate-passage cells. However, after UV exposure at low passages (passage 3), confluent cells were more Sensitive to the killing effects of UV than were log-phase cells. At intermediate passages (passages 43, 48), confluent cells were slightly more radioresistant than were log-phase cells. By passage 64, however, both confluent and log-phase cells showed similar patterns of UV sensitivity. Expression of gamma-actin, PCNA, and p53 transcripts did not change following UV exposure. p53 mRNA was induced following gamma-ray exposure of the intermediate (passage 45) epithelial cells. The observed differences in radiation sensitivity associated with increasing passage number may be influenced by radiation-induced gene expression. We are conducting experiments to identify these genes. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. RI Woloschak, Gayle/A-3799-2017 OI Woloschak, Gayle/0000-0001-9209-8954 NR 27 TC 31 Z9 31 U1 0 U2 0 PU ELSEVIER SCI IRELAND LTD PI CLARE PA CUSTOMER RELATIONS MANAGER, BAY 15, SHANNON INDUSTRIAL ESTATE CO, CLARE, IRELAND SN 0304-3835 J9 CANCER LETT JI Cancer Lett. PD FEB 26 PY 1997 VL 113 IS 1-2 BP 77 EP 86 DI 10.1016/S0304-3835(97)04599-0 PG 10 WC Oncology SC Oncology GA WK873 UT WOS:A1997WK87300012 PM 9065805 ER PT J AU Chamberlin, RM Scott, BL Melo, MM Abney, KD AF Chamberlin, RM Scott, BL Melo, MM Abney, KD TI Butyllithium deprotonation vs alkali metal reduction of cobalt dicarbollide: A new synthetic route to C-substituted derivatives SO INORGANIC CHEMISTRY LA English DT Article ID FLYTRAP CLUSTER REAGENTS; STRUCTURAL CHARACTERIZATION; EXTRACTION; CESIUM AB Reduction of Cs[Co(1,2-C2B9H11)(2)] (Cs[I]) with 1 equiv of Na(Hg) amalgam or Cs metal forms the cobalt(II) dianion, [Co(1,2-C2B9H11)(2)](2-) (II), which reverts to I upon exposure to 0.5 equiv of I-2. The molecular structure of [Cs-2(DME)(4)[Co(1,2-C2B9H11)(2)] shows the carbon atoms of dianion U[ occupy transoid rotational geometry about the cobalt center, consistent with isoelectronic nickel(III) bis(dicarbollide). Reaction of THF solutions of I with 1.0 and 2.0 equiv of n-butyllithium forms purple Cs[Co(LiC2B9H10)(C2B9H11)] (Cs[I-Li]) and blue Cs-[CO(LiC2B9H10)(2)] (Cs[I-Li-2]), respectively. Treating I-Li and I-Li-2 with water causes reversion to I; reaction with D2O forms a dicarbollide C-D bond (IR: v(CD/CH) = 2275/3040 cm(-1)). Mono- and dilithio(cobalt dicarbollide) react with alkyl halides (R-X) to form the corresponding alkyl(cobalt dicarbollide) complexes, [Co(RC(2)B(9)H(10))(C2B9H11)](-) and [Co(RC(2)B(9)H(10))(2)](-) (I-R and I-R(2); R = CH3, C6H13) Alkylation of I-Li-2 using methyl iodide gives a mixture of meso and rac isomers of [Co(1-Me-1,2-C2B9H10)(2)](-) (I-1,1'-Me(2)). In contrast, treating I-Li,Me (generated via deprotonation of I-Me) with methyl iodide forms [Co(1,2-Me(2)-1,2-C2B9H9)- (C2B9H11)](-) (I-1,2-Me(2); 30%), plus meso- and rac-I-1,1'-Me(2) (70% total). The stereochemistry of alkylation is kinetically determined by the sites of deprotonation. Reaction of I-Li-2 with 2 equiv of CH3OCH2CH2OCH2Cl (MEM-CI) produces only the structurally characterized rac isomer of Cs[I-1,1'-MEM(2)]. Crystal data for [Cs-2(DME)(4)][Co(C2B9H11)(2)]: triclinic , a = 9.7930(10) Angstrom, b = 10.1300(10) Angstrom, c = 12.1010(10) Angstrom, alpha = 101.13 degrees, beta = 98.16 degrees, gamma = 114.09 degrees, V = 1042.1(2) Angstrom(3), Z = 1. Crystal data for Cs[Co(1-MEM-1,2-C2B9H10)(2)]: monoclinic P2(1)/c, a = 11.5780(10) Angstrom, b = 14.0880(10) Angstrom, c = 16.998(2) Angstrom, beta = 96.21 degrees, V = 2756.3(4) Angstrom(3), Z = 4. RP Chamberlin, RM (reprint author), LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,MAIL STOP J514,LOS ALAMOS,NM 87545, USA. RI Chamberlin, Rebecca/A-1335-2011; Scott, Brian/D-8995-2017 OI Chamberlin, Rebecca/0000-0001-6468-7778; Scott, Brian/0000-0003-0468-5396 NR 21 TC 37 Z9 37 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD FEB 26 PY 1997 VL 36 IS 5 BP 809 EP 817 DI 10.1021/ic960811x PG 9 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WK289 UT WOS:A1997WK28900015 ER PT J AU Valentine, AM Wilkinson, B Liu, KE KomarPanicucci, S Priestley, ND Williams, PG Morimoto, H Floss, HG Lippard, SJ AF Valentine, AM Wilkinson, B Liu, KE KomarPanicucci, S Priestley, ND Williams, PG Morimoto, H Floss, HG Lippard, SJ TI Tritiated chiral alkanes as substrates for soluble methane monooxygenase from Methylococcus capsulatus (Bath): Probes for the mechanism of hydroxylation SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID METHYLOSINUS-TRICHOSPORIUM OB3B; MONO-OXYGENASE; CYTOCHROME-P-450 HYDROXYLATION; ASYMMETRIC HYDROXYLATION; II METHANOTROPH; COMPONENT-C; PROTEIN-B; OXIDATION; PURIFICATION; HYDROCARBONS AB The tritiated chiral alkanes (S)-[1-H-2(1),1-H-3]ethane, (R)-[1-H-2(1),1-H-3]ethane, (S)-[1-H-2(1),1-H-3]butane, (R)-[1-H-2(1),1-H-3]butane, (S)-[2-H-3]butane, (R)-[2-H-3]butane, and racemic [2-H-3]butane were oxidized by soluble methane monooxygenase (sMMO) from Methylococcus capsulatus (Bath), and the absolute stereochemistry of the resulting product alcohols was determined in order to probe the mechanism of substrate hydroxylation. When purified hydroxylase, coupling protein, and reductase components were used, the product alcohol displayed 72% retention of stereochemistry at the labeled carbon for the ethane substrates and 77% retention for the butanes labeled at the primary carbon. A putative alkyl radical which would yield these product distributions would have a lifetime of 100 fs, a value too short to correspond to a discrete intermediate. Intramolecular k(H)/k(D) ratios of 3.4 and 2.2 were determined for ethane and butane, respectively. When the hydroxylations were performed with purified hydroxylase but only a partially purified cellular extract for the coupling and reductase proteins, different product distributions were observed. These apparently anomalous results could be explained by invoking exchange of hydrogen atoms at the ct carbon of the product alcohols. The characteristics of this exchange reaction are discussed. Hydroxylation of [2-H-3]butanes by the latter system yielded similar to 90% retention of stereochemistry at the labeled carbon. The implication of these results for the catalytic mechanism of sMMO is discussed. Together with the mechanistic information available from a range of substrate probes, the results are best accounted for by a nonsynchronous concerted process involving attack on the C-H bond by one or more of several pathways discussed in the text. C1 UNIV WASHINGTON,DEPT CHEM,SEATTLE,WA 98195. MIT,DEPT CHEM,CAMBRIDGE,MA 02139. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL TRITIUM LABELLING FACIL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. NR 66 TC 105 Z9 105 U1 1 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 FEB 26 PY 1997 VL 119 IS 8 BP 1818 EP 1827 DI 10.1021/ja963971g PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA WK422 UT WOS:A1997WK42200002 ER PT J AU Loeb, KE Westre, TE Kappock, TJ Mitic, N Glasfeld, E Caradonna, JP Hedman, B Hodgson, KO Solomon, EI AF Loeb, KE Westre, TE Kappock, TJ Mitic, N Glasfeld, E Caradonna, JP Hedman, B Hodgson, KO Solomon, EI TI Spectroscopic characterization of the catalytically competent ferrous site of the resting, activated, and substrate-bound forms of phenylalanine hydroxylase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Review ID MAGNETIC-CIRCULAR-DICHROISM; X-RAY-ABSORPTION; NON-HEME IRON; DIOXYGEN BINDING-SITES; TYROSINE-HYDROXYLASE; CRYSTAL-STRUCTURES; SUPEROXIDE-DISMUTASE; ELECTRONIC-STRUCTURE; REVERSIBLE FORMATION; COMPLEXES AB The geometric structure of the catalytically relevant ferrous active site of phenylalanine hydroxylase (PAH) has been investigated using magnetic circular dichroism (MCD) and X-ray absorption (XAS) spectroscopies. From the excited state ligand field transitions in the MCD spectrum (10Dq = 9400 cm(-1), Delta(5)E(g) = 1800 cm(-1)), the temperature and field dependence of these transitions (Delta(5)T(2g) = 590 cm(-1)) , and the XAS pre-edge shapes and intensities, the resting ferrous site of the ''tense'' form of PAH is six-coordinate distorted octahedral. The low ligand field strength observed in the MCD spectrum results from significant oxygen ligation and longer Fe-O/N bond distances relative to model complexes as determined from an EXAFS analysis. Nonallosteric activation using N-ethylmaleimide does not notably affect the band positions in the MCD spectrum and therefore does not perturb the structure of the iron center. However, substrate addition without allosteric activation results in a different six-coordinate distorted octahedral structure as determined by MCD (10Dq = 10 000 cm(-1), Delta(5)E(g) = 1450 cm(-1)) and XAS with a greater d(pi)-orbital splitting (Delta(5)T(2g) = 1050 cm(-1)). EXAFS analysis indicates a shift in the relative number of ligands from the outer to the inner subshell of the first coordination sphere in the substrate-bound form of the enzyme relative to the resting site, consistent with the increased ligand field strength observed directly from the MCD spectrum. Substrate-induced allosteric activation (similar to 34 kcal/mol) does not alter the structure of the iron site in the ''relaxed'' form of PAH compared to the substrate-bound ''tense'' state. Thus, while activation is necessary for the enzyme to achieve complete catalytic competence, it does not appear to affect the geometry of the catalytically relevant six-coordinate ferrous active site and only directly influences the surrounding protein conformation. In contrast, substrate addition results in a geometric and electronic structural change at the iron center which may help orient the substrate for completely coupled hydroxylation. C1 YALE UNIV,DEPT CHEM,NEW HAVEN,CT 06520. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94305. OI Mitic, Natasa/0000-0003-4595-4150 NR 104 TC 48 Z9 48 U1 1 U2 14 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 FEB 26 PY 1997 VL 119 IS 8 BP 1901 EP 1915 DI 10.1021/ja962269h PG 15 WC Chemistry, Multidisciplinary SC Chemistry GA WK422 UT WOS:A1997WK42200010 ER PT J AU Kress, JD Leung, PC Tawa, GJ Hay, PJ AF Kress, JD Leung, PC Tawa, GJ Hay, PJ TI Calculation of a reaction path for KOH catalyzed ring-opening polymerization of hexamethylcyclotrisiloxane SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID POTENTIAL-ENERGY SURFACE; AB-INITIO; MOLECULAR GEOMETRIES; ABINITIO; DISILOXANE; SILICON AB Polysiloxanes represent an important class of industrial polymers. Traditionally, poly (dimethylsiloxane) (PDMS) can be prepared by base-catalyzed ring-opening of cyclic dimethylsiloxanes. Ab initio electronic calculations were conducted to examine a reaction path for the KOH catalyzed ring-opening polymerization of hexamethylcyclotrisiloxane (D-3). The overall picture that emerges is initial side-on attack by KOH on a Si-O bond in the D-3 ring leading to a stable addition complex with a 5-fold coordinated Si atom. The reacth path leads to a five-coordinate transition state, then to a stable insertion product (KOH inserts into the ring). The relative stability of a ring-opened product HO[Si(CH3)(2)O]K-3 is also considered. The energy along the reaction path was modeled both in the gas phase and in a moderately polar solvent (tetrahydrofuran, THF). The solvation energy was calculated using a recent implementation of an electrostatic model, where the solute molecule is placed in a non-spherical cavity in a dielectric continuum. The effect of basis set and electron correlation on the gas-phase energy and the effect of basis set on the solvation energy was studied. Along the solvated reaction path calculated at the Hartree-Fock level (with a 6-31G* basis set for the Si and O atoms), the apparent transition state energy is nearly equal to the reactants energy and is 4 kcal/mol above the addition complex energy. C1 3M CO, TECH COMP DEPT, ST PAUL, MN 55144 USA. RP Kress, JD (reprint author), LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. NR 42 TC 7 Z9 7 U1 0 U2 1 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 FEB 26 PY 1997 VL 119 IS 8 BP 1954 EP 1960 DI 10.1021/ja961190+ PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA WK422 UT WOS:A1997WK42200016 ER PT J AU Grey, CP Poshni, FI Gualtieri, AF Norby, P Hanson, JC Corbin, DR AF Grey, CP Poshni, FI Gualtieri, AF Norby, P Hanson, JC Corbin, DR TI Combined MAS NMR and X-ray powder diffraction structural characterization of hydrofluorocarbon-134 adsorbed on zeolite NaY: Observation of cation migration and strong sorbate-cation interactions SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID FAUJASITE ZEOLITES; ALTERNATIVES; HYDROCARBONS; TEMPERATURE; ADSORPTION; LOCATION; OZONE; METAL AB Na-23 MAS NMR and synchrotron X-ray powder diffraction methods have been used to study the binding of hydrofluorocarbon-134 (HFC-154, CF2HCF2H) in zeolite NaY. A contraction of the volume of the unit cell is observed on gas adsorption, and the interaction of HFC-134 with the extraframework sodium cations is so strong that extraframework sodium cations in the sodalite cages (site I') migrate into the supercages. These sodium cations are found on positions close to the site III' positions of zeolite NaX. Both ends of the HFC molecules are bound to sodium cations, the HFC molecule bridging the site II and III' cations in the supercages. The strong cation-HFC interaction results in a considerable displacement of the sodium site II cation along the [111] direction into the supercage and an increase in the T-O-T bond angle for the three oxygen atoms coordinated to this cation. A decrease in the Na-23 quadrupole coupling constant on HFC adsorption from 4.4 to less than 2.8 MHz, for the sodium cations originally located in the sodalite cages (site I'), is consistent with the sodium cation migrations. C1 UNIV MODENA,DIPARTIMENTO SCI TERRA,I-41100 MODENA,ITALY. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. DUPONT CO INC,CENT RES & DEV,WILMINGTON,DE 19880. RP Grey, CP (reprint author), SUNY STONY BROOK,DEPT CHEM,STONY BROOK,NY 11794, USA. RI Hanson, jonathan/E-3517-2010; Gualtieri, Alessandro/L-9680-2015; Norby, Poul/B-9047-2014 OI Gualtieri, Alessandro/0000-0002-4414-9603; Norby, Poul/0000-0002-2590-7050 NR 39 TC 110 Z9 110 U1 1 U2 18 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 FEB 26 PY 1997 VL 119 IS 8 BP 1981 EP 1989 DI 10.1021/ja963565x PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA WK422 UT WOS:A1997WK42200020 ER PT J AU Steudel, R Drozdova, Y Miaskiewicz, K Hertwig, RH Koch, W AF Steudel, R Drozdova, Y Miaskiewicz, K Hertwig, RH Koch, W TI How unstable are thiosulfoxides? An ab initio MO study of various disulfanes RSSR (R=H, Me, Pr, All), their branched isomers R(2)SS, and the related transition states SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID SULFUR-SULFUR BONDS; MOLECULAR-STRUCTURE; PROJECTION OPERATORS; BASIS-SETS; ABINITIO; DENSITY; ATOMS; HPLC; DIMETHOXYDISULFANE; DISULFIDES AB Ab initio MO calculations at the MP2/6-311G** level of theory show that the thiosulfoxide H2SS is 143 kJ mol(-1) less stable than the disulfane HSSH, separated by an activation barrier of 210 kJ mol(-1). Using much higher levels of theory, these results are only slightly changed, proving the suitability of the economical MP2/6-311G** scheme for the present purpose. At the same level Me(2)SS is 84 kJ mol(-1) less stable than MeSSMe, with the transition state lying 340 kJ mol(-1) above MeSSMe. Thermal isomerization of HSSH or MeSSMe can therefore be excluded, and H2SS and Me(2)SS should be kinetically stable toward unimolecular isomerization at low temperatures, Vibrational wavenumbers for H2SS and Me(2)SS are given. The allyl methyl thiosulfoxide MeAllSS is 83 kJ mol(-1) less stable than the disulfane MeSSAll, but isomerization of the latter requires only 110 kJ mol(-1). The corresponding RSSR and R(2)SS structures for R = Pr and All have been calculated at the HF/6-31G* level. The bimolecular decomposition of dimethyl thiosulfoxide to dimethyl sulfide and S-2 is exothermic but spin-forbidden in the case of triplet S-2, and endothermic but spin-allowed when singlet S-2 is formed. The reactions of Me(2)SS with sulfur molecules S-x (x > 2) to give Me(2)S and S-x+1 are exothermic. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. TECH UNIV BERLIN, INST ORGAN CHEM, D-10623 BERLIN, GERMANY. RP Steudel, R (reprint author), TECH UNIV BERLIN, INST ANORGAN & ANALYT CHEM, SEKR C2, D-10623 BERLIN, GERMANY. NR 64 TC 60 Z9 61 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 FEB 26 PY 1997 VL 119 IS 8 BP 1990 EP 1996 DI 10.1021/ja9624026 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA WK422 UT WOS:A1997WK42200021 ER PT J AU Boese, R Matzger, AJ Vollhardt, KPC AF Boese, R Matzger, AJ Vollhardt, KPC TI Synthesis, crystal structure, and explosive decomposition of 1,2:5,6:11,12:15,16-tetrabenzo-3,7,9,13,17,19-hexadehydro[20]annulene: Formation of onion- and tube-like closed-shell carbon particles SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID DIACETYLENE; NANOTUBES; POLYMERIZATION; RING C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CHEM,DIV CHEM SCI,BERKELEY,CA 94720. UNIV ESSEN GESAMTHSCH,INST INORGAN CHEM,D-45117 ESSEN,GERMANY. RI Matzger, Adam/G-7497-2016 OI Matzger, Adam/0000-0002-4926-2752 NR 41 TC 137 Z9 137 U1 1 U2 13 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 FEB 26 PY 1997 VL 119 IS 8 BP 2052 EP 2053 DI 10.1021/ja963845c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WK422 UT WOS:A1997WK42200029 ER PT J AU Harris, NT Goldstein, B Holowka, D Baird, B AF Harris, NT Goldstein, B Holowka, D Baird, B TI Altered patterns of tyrosine phosphorylation and Syk activation for sterically restricted cyclic dimers of IgE-Fc epsilon RI SO BIOCHEMISTRY LA English DT Article ID BASOPHILIC LEUKEMIA-CELLS; HIGH-AFFINITY RECEPTOR; IMMUNOGLOBULIN-E-RECEPTOR; RBL-2H3 MAST-CELLS; PROTEIN-KINASE-C; CROSS-LINKING; T-CELL; PHOSPHOLIPASE C-GAMMA-1; HISTAMINE-RELEASE; GAMMA-SUBUNITS AB Previous studies in our laboratory established that the symmetrical bivalent ligand, N,N'-bis[[epsilon-(2,4-dinitrophenyl)amino] caproyl] -L-tyrosyl]-L-cystine ((DCT)(2)-cys), stably cross-links anti-2,4-dinitrophenyl-immunoglobulin E (IgE) bound to high affinity receptors Fc epsilon RI on the surface of RBL-2H3 cells, forming mostly cyclic dimers containing two IgE-Fc epsilon RI and two (DCT)(2)-cys (Posner et al. (1995) J. Immunol. 155, 3601-3509). These cyclic dimers do not trigger Ca2+ or degranulation responses under a variety of conditions. However, we find that the linearly cross-linked IgE-Fc epsilon RI formed at higher concentrations of (DCT)(2)-cys do trigger degranulation in the presence of cytochalasin D, an inhibitor of actin polymerization. We further investigated stimulation by (DCT)(2)-cys of the earliest known events in the functional response, i.e., tyrosine phosphorylation of the beta and gamma subunits of Fc epsilon RI. At the higher (DCT)(2)-cys concentrations corresponding to linear dimers and maximal degranulation, tyrosine phosphorylation of both beta and gamma are observed. At lower (DCT)(2)-cys concentrations where cross-linking is maximal and cyclic dimers are overwhelmingly dominant, only gamma tyrosine phosphorylation is observed. Cytochalasin D does not affect these phosphorylation patterns, but instead appears to enhance coupling to downstream signaling events. Phosphorylation of Syk occurs at the higher (DCT)(2)-cys concentrations in parallel with beta phosphorylation but does not occur in its absence at the lower (DCT)(2)-cys concentrations. These results suggest that cyclic dimers of IgE-Fc epsilon RI are sterically restricted such that they stimulate tyrosine phosphorylation of gamma but not beta, and this is not sufficient for Syk binding and/or activation. C1 CORNELL UNIV,DEPT CHEM,ITHACA,NY 14853. LOS ALAMOS NATL LAB,DIV THEORET,THEORET BIOL & BIOPHYS GRP,LOS ALAMOS,NM 87545. FU NIAID NIH HHS [AI22449]; NIGMS NIH HHS [GM35556, GM07273] NR 51 TC 18 Z9 18 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 FEB 25 PY 1997 VL 36 IS 8 BP 2237 EP 2242 DI 10.1021/bi9619839 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WK479 UT WOS:A1997WK47900035 PM 9047325 ER PT J AU Nehlin, JO Hara, E Kuo, WL Collins, C Campisi, J AF Nehlin, JO Hara, E Kuo, WL Collins, C Campisi, J TI Genomic organization, sequence, and chromosomal localization of the human helix-loop-helix Id1 gene SO BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS LA English DT Article ID MAMMALIAN-CELLS; DNA-BINDING; PROTEIN; DIFFERENTIATION; EXPRESSION; MUSCLE AB The helix-loop-helix protein Id-1 regulates growth and differentiation in many mammalian cells. In human fibroblasts, Id1 and Id1', a putative splicing variant, are cell cycle regulated, essential for proliferation, repressed by senescence, and overexpressed by some tumor cells, To better understand Id1, we determined the complete sequence, transcriptional start, and localization of the human Id1 gene. Human Id1 has two exons (426 Thp and 42 bp), separated by an intron (239 bp). Id1' results from failure to splice the intron, which encodes 7 amino acids prior to a stop codon, Thus, Id1 and Id1' proteins differ only at the extreme C-terminus. Id1 transcription initiated 96 bp upstream of the initiation AUG; 2 kb of upstream sequence stimulated transcription of a reporter gene, Human Id1 maps to chromosome 20 at q11, very close to the centromere but outside the amplicons frequently found in human cancers. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT CANC BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,MOL CYTOGENET RESOURCE,BERKELEY,CA 94720. FU NIA NIH HHS [AG09909, AG11658] NR 27 TC 29 Z9 31 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 0006-291X J9 BIOCHEM BIOPH RES CO JI Biochem. Biophys. Res. Commun. PD FEB 24 PY 1997 VL 231 IS 3 BP 628 EP 634 DI 10.1006/bbrc.1997.6152 PG 7 WC Biochemistry & Molecular Biology; Biophysics SC Biochemistry & Molecular Biology; Biophysics GA WK484 UT WOS:A1997WK48400025 PM 9070860 ER PT J AU Rabion, A Buchanan, RM Seris, JL Fish, RH AF Rabion, A Buchanan, RM Seris, JL Fish, RH TI Biomimetic oxidation studies .10. Cyclohexane oxidation reactions with active site methane monooxygenase enzyme models and t-butyl hydroperoxide in aqueous micelles: Mechanistic insights and the role of t-butoxy radicals in the C-H functionalization reaction SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Letter DE aqueous micelles; aqueous biomimetic oxidations; t-butoxy radicals; hydrocarbon oxidation in micelles; MMO biomimics ID ALKANE FUNCTIONALIZATION; CENTERS AB The oxidation of cyclohexane (CyH) in an aqueous micelle system with t-butyl hydroperoxide (TBHP) in the presence of biomimetic methane monooxygenase enzyme complexes, [Fe2O(eta(1)-H2O)(eta(1)-OAc)(TPA)(2)](3+), 1, [Fe2O(eta(1)-H2O)(eta(1)-OAc)(BPIA)(2)](3+), 2, and O-2, was studied and found to provide cyclohexanol (CyOH), cyclohexanone (CyONE), and cyclohexyl-t-butyl peroxide (CyOOt-Bu). The mechanistic aspects of this oxidation reaction in aqueous micelles were studied and included the effects of the surfactant concentration, cetyltrimethylammonium hydrosulfate; concentration of CyH and TBHP; and a trapping reagent, CCl4. Several factors allowed us to conclude that a t-butoxy radical (t-BuO(.)) was generated from the favorable redox chemistry of the biomimetic complexes with TBHP, and was responsible for the free radical initiation process with CyH in the aqueous micelle system. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. UNIV LOUISVILLE,DEPT CHEM,LOUISVILLE,KY 40292. ELF AQUITAINE CO,GRP RECH LACQ,F-64170 ARTIX,FRANCE. NR 16 TC 29 Z9 30 U1 2 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD FEB 24 PY 1997 VL 116 IS 1-2 BP 43 EP 47 DI 10.1016/S1381-1169(96)00230-0 PG 5 WC Chemistry, Physical SC Chemistry GA WH655 UT WOS:A1997WH65500006 ER PT J AU Ferry, A Tian, MM AF Ferry, A Tian, MM TI Influence of hydroxyl terminal groups on the ionic speciation and ionic conductivity in complexes of poly(propylene glycol)(4000) and LiCF3SO3 salt SO MACROMOLECULES LA English DT Article ID MICROPHASE SEPARATION; POLYMER ELECTROLYTES; TRIFLATE; ASSOCIATION; OXIDE); BEHAVIOR; LITHIUM; SODIUM; LICLO4 C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Ferry, A (reprint author), UMEA UNIV,DEPT PHYS,S-90187 UMEA,SWEDEN. NR 16 TC 23 Z9 23 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 24 PY 1997 VL 30 IS 4 BP 1214 EP 1215 DI 10.1021/ma961387m PG 2 WC Polymer Science SC Polymer Science GA WK315 UT WOS:A1997WK31500071 ER PT J AU Ormand, WE Bortignon, PF Broglia, RA Bracco, A AF Ormand, WE Bortignon, PF Broglia, RA Bracco, A TI Behavior of the giant-dipole resonance in Sn-120 and Pb-208 at high excitation energy SO NUCLEAR PHYSICS A LA English DT Article ID HOT ROTATING NUCLEI; FINITE TEMPERATURE; THERMAL FLUCTUATIONS; COLLECTIVE MOTION; SHAPE TRANSITIONS; WIDTH; DEPENDENCE; SPIN AB The properties of the giant-dipole resonance (GDR) are calculated as a function of excitation energy, angular momentum, and the compound nucleus particle decay width in the nuclei Sn-120 and Pb-208, and are compared with recent experimental data. Differences observed in the behavior of the full-width-ae-half-maximum of the GDR for Sn-120 and Pb-208 are attributed to the fact that shell corrections in Pb-208 are stronger than in Sn-120, and favor the spherical shape at low temperatures. The effects shell corrections have on both the free energy and the moments of inertia are discussed in detail. At high temperature, the FWHM in Sn-120 exhibits effects due to the evaporation width of the compound nucleus, while these effects are predicted for Pb-208. C1 IST NAZL FIS NUCL,I-20133 MILAN,ITALY. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV COPENHAGEN,NIELS BOHR INST,DK-2100 COPENHAGEN O,DENMARK. RP Ormand, WE (reprint author), UNIV MILAN,DIPARTIMENTO FIS,VIA CELORIA 16,I-20133 MILAN,ITALY. NR 46 TC 68 Z9 68 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 FEB 24 PY 1997 VL 614 IS 2 BP 217 EP 237 DI 10.1016/S0375-9474(96)00464-2 PG 21 WC Physics, Nuclear SC Physics GA WL846 UT WOS:A1997WL84600003 ER PT J AU Diamond, PH Lebedev, VB Newman, DE Carreras, BA Hahm, TS Tang, WM Rewoldt, G Avinash, K AF Diamond, PH Lebedev, VB Newman, DE Carreras, BA Hahm, TS Tang, WM Rewoldt, G Avinash, K TI Dynamics of transition to enhanced confinement in reversed magnetic shear discharges SO PHYSICAL REVIEW LETTERS LA English DT Article ID H-MODE TRANSITION; TRANSPORT; TOKAMAK; REGIME; ENERGY; PLASMA; TFTR AB A simple model of the transition to enhanced confinement in reversed shear discharges is presented. The proposed transition mechanism relies on a synergism between electric field shear suppression of turbulence aided by reduced curvature drive due to magnetic shear reversal or reduction. Profile structure and transport barrier propagation dynamics are predicted. A novel analytical theory for the time evolution of the barrier foot-point location is presented. The model predicts that the transition threshold has favorable dependence on pretransition temperature ratio (T-i/T-e), in-out asymmetry in the E x B shearing rate (i.e., lower for larger Shafranov shift), density profile peakedness, and unfavorable scaling with density. Optimal confinement occurs in discharges where deposition is peaked within the magnetic shear reversal radius. C1 OAK RIDGE NATL LAB,DIV FUS ENERGY,OAK RIDGE,TN 37831. PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08544. INST PLASMA RES,GANDHI SAGAR 382424,INDIA. GEN ATOM CO,SAN DIEGO,CA 92122. RP Diamond, PH (reprint author), UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093, USA. NR 22 TC 80 Z9 80 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 FEB 24 PY 1997 VL 78 IS 8 BP 1472 EP 1475 DI 10.1103/PhysRevLett.78.1472 PG 4 WC Physics, Multidisciplinary SC Physics GA WK157 UT WOS:A1997WK15700019 ER PT J AU Argyriou, DN Mitchell, JF Goodenough, JB Chmaissem, O Short, S Jorgensen, JD AF Argyriou, DN Mitchell, JF Goodenough, JB Chmaissem, O Short, S Jorgensen, JD TI Sign reversal of the Mn-O bond compressibility in La1.2Sr1.8Mn2O7 below T-C: Exchange striction in the ferromagnetic state SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRESSURE-DEPENDENCE; CHARGE-TRANSFER; INSULATOR-TRANSITION; LA1-XSRXMNO3 AB The crystal structure of the layered perovskite La1.2Sr1.8Mn2O7 has been studied under hydrostatic pressure up to similar to 6 kbar, in the paramagnetic and ferromagnetic states, with neutron powder diffraction. The compressibility of the Mn-O apical bonds in the double layer of MnO6 octahedra changes sign from the paramagnetic insulator (PI) to the ferromagnetic metal (FM) state; in the FM state the Mn-O-Mn linkage between MnO2 planes expands under applied pressure, whereas they contract in the PI state. This counterintuitive behavior is interpreted in terms of exchange striction, which reflects the competition between super and double exchange. An increase of the Mn moment with applied pressure in the FM state is consistent with a positive dT(C)/dP, as well as a cant angle theta(0) between the magnetizations of neighboring MnO2 sheets that decreases with pressure. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. UNIV TEXAS,CTR MAT SCI & ENGN,AUSTIN,TX 78712. RP Argyriou, DN (reprint author), ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCTIV,ARGONNE,IL 60439, USA. NR 16 TC 131 Z9 134 U1 0 U2 16 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 24 PY 1997 VL 78 IS 8 BP 1568 EP 1571 DI 10.1103/PhysRevLett.78.1568 PG 4 WC Physics, Multidisciplinary SC Physics GA WK157 UT WOS:A1997WK15700043 ER PT J AU Shor, P Laflamme, R AF Shor, P Laflamme, R TI Quantum analog of the MacWilliams identities for classical coding theory SO PHYSICAL REVIEW LETTERS LA English DT Article ID COMPUTERS AB We derive a relationship between two different notions of fidelity (entanglement fidelity and average fidelity) for a completely depolarizing quantum channel. This relationship gives rise to a quantum analog of the MacWilliams identities in classical coding theory. These identities relate the weight enumerator of a code to the one of its dual and, with linear programming techniques, provide a powerful tool to investigate the possible existence of codes. The same techniques can be adapted to the quantum case. We give examples of their power. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV CALIF SANTA BARBARA,INST THEORET PHYS,SANTA BARBARA,CA 93106. RP Shor, P (reprint author), AT&T BELL LABS,RES,ROOM 2D-149,600 MT AVE,MURRAY HILL,NJ 07974, USA. NR 20 TC 51 Z9 52 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 FEB 24 PY 1997 VL 78 IS 8 BP 1600 EP 1602 DI 10.1103/PhysRevLett.78.1600 PG 3 WC Physics, Multidisciplinary SC Physics GA WK157 UT WOS:A1997WK15700051 ER PT J AU Jones, JA Pines, A AF Jones, JA Pines, A TI Geometric dephasing in zero-field magnetic resonance SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NUCLEAR-QUADRUPOLE RESONANCE; SPIN-ROTATIONAL RELAXATION; ADIABATIC ROTATION; BERRYS PHASE; NMR; XENON AB Geometric phases acquired randomly can give rise to coherence dephasing in nuclear spin systems, equivalent to spin relaxation. We calculate the form and extent of this geometric dephasing in a number of model systems involving the motion of Xe-131 nuclei in shaped containers. The dephasing is calculated in two ways: first, using an analytical treatment of the diffusive motion of individual nuclei, and second, using ensemble averaged propagators. The effects of applying additional magnetic fields to these systems are discussed briefly. (C) 1997 American Institute of Physics. C1 UNIV OXFORD MERTON COLL,OXFORD OX1 4JD,ENGLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. RP Jones, JA (reprint author), UNIV OXFORD,OXFORD CTR MOL SCI,NEW CHEM LAB,S PARKS RD,OXFORD OX1 3QT,ENGLAND. RI Jones, Jonathan/E-4585-2011 OI Jones, Jonathan/0000-0003-1862-587X NR 28 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 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD FEB 22 PY 1997 VL 106 IS 8 BP 3007 EP 3016 DI 10.1063/1.473046 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WH843 UT WOS:A1997WH84300003 ER PT J AU Osborn, DL Choi, H Mordaunt, DH Bise, RT Neumark, DM Rohlfing, CM AF Osborn, DL Choi, H Mordaunt, DH Bise, RT Neumark, DM Rohlfing, CM TI Fast beam photodissociation spectroscopy and dynamics of the vinoxy radical SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POSITION-SENSITIVE DETECTOR; LASER-INDUCED FLUORESCENCE; FLIGHT MASS-SPECTROMETER; MOLECULAR-BEAM; CONFIGURATION-INTERACTION; GAUSSIAN-2 THEORY; DISSOCIATION; STATE; CH3CO; BENZENE AB The spectroscopy and photodissociation dynamics of the vinery (CH2CHO) radical (B) over tilde((2)A '') <--(X) over tilde((2)A '') transition have been investigated by fast beam photofragment translational spectroscopy. We show conclusively that excitation to the B state is followed by predissociation, even for the origin transition. Two photodissociation channels are observed: (1) CH3+CO, and (2) H+CH2CO, with a branching ratio of approximate to 1:4. The form of the translational energy distributions imply a significant exit barrier to formation of CH3+CO, and a considerably smaller barrier for H+CH2CO formation. Dissociation ultimately proceeds by internal conversion to the ground electronic state; the internal conversion rate appears to be significantly enhanced by a curve crossing with either the (A) over tilde((2)A') or (C) over tilde(2A') states. Ab initio calculations of critical points on the global potential energy surfaces aid in determining the dissociation mechanism. We present a simple model for dissociation over a barrier, the statistical adiabatic impulsive model, which satisfactorily reproduces the translational energy distributions. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Osborn, DL (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Osborn, David/A-2627-2009; Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 82 TC 86 Z9 87 U1 1 U2 9 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 FEB 22 PY 1997 VL 106 IS 8 BP 3049 EP 3066 DI 10.1063/1.473419 PG 18 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WH843 UT WOS:A1997WH84300008 ER PT J AU Karbowiak, M Drozdzynski, J Murdoch, KM Edelstein, NM Hubert, S AF Karbowiak, M Drozdzynski, J Murdoch, KM Edelstein, NM Hubert, S TI Spectroscopic studies and crystal-field analysis of U3+ ions in RbY2Cl7 single crystals SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LANTHANIDES; ACTINIDES; SPECTRUM AB Single crystals of U3+ diluted into a matrix of RbY2Cl7 have been grown by the Bridgman-Stockbarger method. There are two different intrinsic U3+ sites in this crystalline host, each with an approximate C-2 upsilon Site symmetry. A third minor U3+ Site was also found. Absorption, fluorescence, and excitation spectra of these crystals were obtained at 300 and 4.2 K. Transitions belonging to each U3+ Site were distinguished by time-gated site-selective spectroscopy. The energy levels of the two intrinsic sites were assigned and fitted to a semiempirical Hamiltonian representing the combined atomic and crystal-field interactions for a 5f(3) ion at a C-2 upsilon symmetry site. Quite different F-4(9/2) fluorescence lifetimes were measured for the three sites, due to a multiphonon decay mechanism which is affected by differences in their respective crystal-field strengths. These results are analyzed quantitatively using the theory for the electron-phonon interaction. (C) 1997 American Institute of Physics. C1 LAWRENCE BERKELEY LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. INST PHYS NUCL, IN2P3, CNRS, F-91406 ORSAY, FRANCE. RP Karbowiak, M (reprint author), UNIV WROCLAW, FAC CHEM, UL JOLIOT CURIE 14, PL-50383 WROCLAW, POLAND. NR 19 TC 22 Z9 22 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 FEB 22 PY 1997 VL 106 IS 8 BP 3067 EP 3077 DI 10.1063/1.473050 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WH843 UT WOS:A1997WH84300009 ER PT J AU Williams, S Rohlfing, EA Rahn, LA Zare, RN AF Williams, S Rohlfing, EA Rahn, LA Zare, RN TI Two-color resonant four-wave mixing: Analytical expressions for signal intensity SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INDUCED GRATING SPECTROSCOPY; LASER-INDUCED GRATINGS; DEGENERATE 4-WAVE-MIXING SPECTRA; ROTATIONAL LINE-STRENGTHS; FREE JETS; RELATIVE POPULATIONS; INDUCED FLUORESCENCE; DECOMPOSITION METHOD; NITRIC-OXIDE; FIELD LIMIT AB We present analytical signal expressions for each two-color resonant four-wave mixing (TC-RFWM) scheme that can be used for double-resonance molecular spectroscopy in the limit of weak fields (no saturation). The theoretical approach employs time-independent, diagrammatic perturbation theory and a spherical tensor analysis in an extension of recent treatments of degenerate four-wave mixing [S. Williams, R. N. Zare, and L. A. Rahn, J. Chem. Phys. 101, 1072(1994)] and TC-RFWM for the specific case of stimulated emission pumping [S. Williams et al., J. Chem. Phys. 102, 8342 (1995)]. Under the assumption that the relaxation of the population, the orientation, and the alignment are the same, simple analytic expressions are derived for commonly used experimental configurations. The TC-RFWM signal is found to be a product of a concentration term, a one-photon molecular term, a line shape function, and a laboratory-frame geometric factor. These expressions are intended to facilitate the practical analysis of TC-RFWM spectra by clarifying, for example, the dependence on beam polarizations and rotational branch combinations. (C) 1997 American institute of Physics. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305. PHILLIPS LAB,GPID,HANSCOM AFB,MA 01731. RI Zare, Richard/A-8410-2009; OI Rahn, Larry/0000-0002-4793-1158 NR 55 TC 47 Z9 47 U1 1 U2 6 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 FEB 22 PY 1997 VL 106 IS 8 BP 3090 EP 3102 DI 10.1063/1.473052 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WH843 UT WOS:A1997WH84300011 ER PT J AU Xantheas, SS Dunning, TH Mavridis, A AF Xantheas, SS Dunning, TH Mavridis, A TI The dissociation energies of NF(X(3)Sigma(-)) and NCl(X(3)Sigma(-)) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; MOLECULAR WAVE-FUNCTIONS; GAUSSIAN-BASIS SETS; SIZE-EXTENSIVE MODIFICATION; BENCHMARK CALCULATIONS; GEOMETRICAL STRUCTURE; ELECTRONIC-STRUCTURE; DIATOMIC HYDRIDES; RADICALS-NF; AB-INITIO AB We have computed potential energy functions for the ground states (X (3) Sigma(-)) of NF and NCl using a series of correlation consistent basis sets ranging from double to sextuple zeta quality and including core-valence correlation effects in conjunction with coupled-cluster single and double excitations with perturbative treatment of triple excitations [CCSD(T)] and large internally contracted multireference configuration interaction (icMRCI) wave functions. The best estimates for the dissociation energies (D-e's) are 76.6+/-1.3 kcal/mol for NF and 64.6+/-1.3 kcal/mol for NCl, respectively. Our results suggest that previous experimental estimates for the dissociation energy of NCl are in error by as much as 15 kcal/mol. The calculated spectroscopic constants for NF and NCl are in good agreement with the measured constants. (C) 1997 American Institute of Physics. C1 NATL KAPODISTRIAN UNIV ATHENS, DEPT CHEM, PHYS CHEM LAB, ZOGRAFOS, GREECE. RP Xantheas, SS (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999,MS K1-96, RICHLAND, WA 99352 USA. RI Xantheas, Sotiris/L-1239-2015; OI Xantheas, Sotiris/0000-0002-6303-1037 NR 57 TC 37 Z9 37 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 FEB 22 PY 1997 VL 106 IS 8 BP 3280 EP 3286 DI 10.1063/1.474120 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WH843 UT WOS:A1997WH84300029 ER PT J AU Holroyd, RA Itoh, K Nishikawa, M AF Holroyd, RA Itoh, K Nishikawa, M TI Studies of e(-)+CO2 greater than or less than CO2- equilibria in hexamethyldisiloxane and bis(trimethylsilyl)methane SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CONDUCTION-BAND ENERGY; NONPOLAR LIQUIDS; PRESSURE; ELECTRONS; CO2 AB Electrons react reversibly with CO2 in bis(trimethylsilyl)methane and hexamethyldisiloxane. This reaction is studied as a function of both temperature and pressure. The ground state energies of electrons are deduced and are quite low consistent with the observed high electron mobility. A linear dependence of the log of the attachment rate on the free energy of reaction is observed. The dependence of the equilibrium constant on pressure indicates the electrostriction volume of CO2- to be approximate to -200 cm(3)/mol in these liquids. C1 UNIV TOKYO,DEPT PURE & APPL SCI,TOKYO 153,JAPAN. KANAGAWA INST TECHNOL,FAC ENGN,ATSUGI,KANAGAWA 24302,JAPAN. RP Holroyd, RA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. NR 15 TC 7 Z9 7 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 FEB 21 PY 1997 VL 266 IS 1-2 BP 227 EP 232 DI 10.1016/S0009-2614(97)01536-4 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WJ276 UT WOS:A1997WJ27600036 ER PT J AU Lochter, A Srebrow, A Sympson, CJ Terracio, N Werb, Z Bissell, MJ AF Lochter, A Srebrow, A Sympson, CJ Terracio, N Werb, Z Bissell, MJ TI Misregulation of stromelysin-1 expression in mouse mammary tumor cells accompanies acquisition of stromelysin-1-dependent invasive properties SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID PROTEIN GENE-EXPRESSION; EXTRACELLULAR-MATRIX; EPITHELIAL-CELLS; BASEMENT-MEMBRANE; IV COLLAGENASE; SYNOVIAL FIBROBLASTS; ENZYMATIC-PROPERTIES; TISSUE INHIBITOR; TRANSGENIC MICE; METALLOPROTEINASES AB Stromelysin-1 is a member of the metalloproteinase family of extracellular matrix-degrading enzymes that regulates tissue remodeling, We previously established a transgenic mouse model in which rat stromelysin-1 targeted to the mammary gland augmented expression of endogenous stromelysin-l, disrupted functional differentiation, and induced mammary tumors. A cell line generated from an adenocarcinoma in one of these animals and a previously described mammary tumor cell line generated in culture readily invaded both a reconstituted basement membrane and type I collagen gels, whereas a nonmalignant, functionally normal epithelial cell line did not. Invasion of Matrigel by tumor cells was largely abolished by metalloproteinase inhibitors, but not by inhibitors of other proteinase families. Inhibition experiments with antisense oligodeoxynucleotides revealed that Matrigel invasion of both cell lines was critically dependent on stromelysin-l expression. Invasion of collagen, on the other hand, was reduced by only 40-50%. Stromelysin-l was expressed in both malignant and nonmalignant cells grown on plastic substrata. Its expression was completely inhibited in nonmalignant cells, but up-regulated in tumor cells, in response to Matrigel. Thus misregulation of stromelysin-1 expression appears to be an important aspect of mammary tumor cell progression to an invasive phenotype. C1 UNIV CALIF SAN FRANCISCO,DEPT ANAT,SAN FRANCISCO,CA 94143. RP Lochter, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA 57621, CA 58207] NR 43 TC 111 Z9 114 U1 1 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 FEB 21 PY 1997 VL 272 IS 8 BP 5007 EP 5015 PG 9 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WJ855 UT WOS:A1997WJ85500051 PM 9030563 ER PT J AU Guiochon, G Farkas, T GuanSajonz, H Koh, JH Sarker, M Stanley, BJ Yun, T AF Guiochon, G Farkas, T GuanSajonz, H Koh, JH Sarker, M Stanley, BJ Yun, T TI Consolidation of particle beds and packing of chromatographic columns SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 20th International Symposium on High Performance Liquid Phase Separations and Related Techniques CY JUN 16-21, 1996 CL SAN FRANCISCO, CA DE column packing; stationary phases, LC; packing methods; reviews ID AXIAL-COMPRESSION COLUMNS; LIQUID-CHROMATOGRAPHY; PREPARATIVE CHROMATOGRAPHY; PERFORMANCE; HETEROGENEITY; EFFICIENCY; BEHAVIOR; SCALE AB A variety of complementary evidence reviewed here demonstrates that the packing of chromatographic columns is heterogeneous. It is denser and less well organized close to the column wall than in the center of the column. The mechanism of particle consolidation under stress explains the origin of this phenomenon and provides a fundamental justification to what is known in column chromatography as ''the wall effect''. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Guiochon, G (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 38 TC 88 Z9 90 U1 7 U2 14 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 FEB 21 PY 1997 VL 762 IS 1-2 BP 83 EP 88 DI 10.1016/S0021-9673(96)00642-5 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WP082 UT WOS:A1997WP08200010 PM 9098968 ER PT J AU Tong, W Yeung, ES AF Tong, W Yeung, ES TI Monitoring single-cell pharmacokinetics by capillary electrophoresis and laser-induced native fluorescence SO JOURNAL OF CHROMATOGRAPHY B LA English DT Article DE insulin; digitonin ID ADRENAL-MEDULLARY CELLS; HUMAN ERYTHROCYTES; INSULIN-SECRETION; ELECTROCHEMICAL DETECTION; CATECHOLAMINE SECRETION; ZONE ELECTROPHORESIS; CHROMAFFIN CELLS; VESICLE FUSION; NERVE-CELLS; BETA-CELLS AB The quantification of insulin released from single cells of the insulin-secreting cell line beta TC3 permeabilized by digitonin is demonstrated. A simple method for monitoring the on-column release process by using capillary electrophoresis and laser-induced native fluorescence detection is described. Quantitative measurements of both the amount of insulin released and the amount remaining in the cell can be achieved simultaneously. This protocol provides an alternative approach to the study of cell secretion in the fields of neuroscience and endocrinology. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. NR 39 TC 51 Z9 56 U1 2 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4347 J9 J CHROMATOGR B JI J. Chromatogr. B PD FEB 21 PY 1997 VL 689 IS 2 BP 321 EP 325 DI 10.1016/S0378-4347(96)00317-9 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WV314 UT WOS:A1997WV31400006 PM 9080317 ER PT J AU BarYam, Z Cummings, JP Dowd, JP Eugenio, P Hayek, M Kern, W King, E Shenhav, N Chung, SU Hackenburg, RW Olchanski, C Weygand, DP Willutzki, HJ Brabson, BB Crittenden, RR Dzierba, AR Gunter, J Lindenbusch, R Rust, DR Scott, E Smith, PT Sulanke, T Teige, S Denisov, S Dushkin, A Kochetkov, V Lipaev, V Popov, A Shein, I Soldatov, A Anoshina, EV Bodyagin, VA Demianov, AI Gribushin, AM Kodolova, OL Korotkikh, VL Kostin, MA Ostrovidov, AI Sarycheva, LI Sinev, NB Vardanyan, IN Yershov, AA Adams, T Bishop, JM Cason, NM Sanjari, AH LoSecco, JM Manak, JJ Shephard, WD Stienike, DL Taegar, SA Thompson, DR Brown, DS Pedlar, T Seth, KK Wise, J Zhao, D Adams, GS Napolitano, J Nozar, M Smith, JA Witkowski, M AF BarYam, Z Cummings, JP Dowd, JP Eugenio, P Hayek, M Kern, W King, E Shenhav, N Chung, SU Hackenburg, RW Olchanski, C Weygand, DP Willutzki, HJ Brabson, BB Crittenden, RR Dzierba, AR Gunter, J Lindenbusch, R Rust, DR Scott, E Smith, PT Sulanke, T Teige, S Denisov, S Dushkin, A Kochetkov, V Lipaev, V Popov, A Shein, I Soldatov, A Anoshina, EV Bodyagin, VA Demianov, AI Gribushin, AM Kodolova, OL Korotkikh, VL Kostin, MA Ostrovidov, AI Sarycheva, LI Sinev, NB Vardanyan, IN Yershov, AA Adams, T Bishop, JM Cason, NM Sanjari, AH LoSecco, JM Manak, JJ Shephard, WD Stienike, DL Taegar, SA Thompson, DR Brown, DS Pedlar, T Seth, KK Wise, J Zhao, D Adams, GS Napolitano, J Nozar, M Smith, JA Witkowski, M TI A cylindrical drift chamber with azimuthal and axial position readout SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE partial detector; drift chamber; cylindrical charge division AB A cylindrical multiwire drift chamber with axial charge-division has been constructed and used in experiment E852 at Brookhaven National Laboratory. It serves as a trigger element and as a tracking device for recoil protons in pi(-)p interactions. We describe the chamber's design considerations, details of its construction, electronics, and performance characteristics. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. INDIANA UNIV,BLOOMINGTON,IN 47405. INST HIGH ENERGY PHYS,PROTVINO,RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV,INST PHYS NUCL,MOSCOW,RUSSIA. UNIV NOTRE DAME,NOTRE DAME,IN 46556. NORTHWESTERN UNIV,EVANSTON,IL 60208. RENSSELAER POLYTECH INST,TROY,NY 12180. RP BarYam, Z (reprint author), UNIV MASSACHUSETTS,N DARTMOUTH,MA 02747, USA. RI Demianov, Andrei/E-4565-2012; Vardanyan, Irina/K-7981-2012; Gribushin, Andrei/J-4225-2012 NR 9 TC 14 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 21 PY 1997 VL 386 IS 2-3 BP 235 EP 248 DI 10.1016/S0168-9002(96)01032-7 PG 14 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700004 ER PT J AU Bauer, G Bieser, F Brady, FP Chance, JC Christie, WF Gilkes, M Lindenstruth, V Lynen, U Muller, WFJ Romero, JL Sann, H Tull, CE Warren, P AF Bauer, G Bieser, F Brady, FP Chance, JC Christie, WF Gilkes, M Lindenstruth, V Lynen, U Muller, WFJ Romero, JL Sann, H Tull, CE Warren, P TI A multiple sampling time projection ionization chamber for nuclear fragment tracking and charge measurement SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB A detector has been developed for the tracking and charge measurement of the projectile fragment nuclei produced in relativistic nuclear collisions. This device, MUSIC II, is a second generation Multiple Sampling Ionization Chamber (MUSIC), and employs the principles of ionization and time projection chambers. It provides unique charge determination for charges Z greater than or equal to 6, and excellent track position measurement. MUSIC II has been used most recently with the EOS (Equation of State) TPC and other EOS Collaboration detectors. Earlier it was used with other systems in experiments at the Heavy Ion Superconducting Spectrometer (HISS) facility at Lawrence Berkeley Laboratory and the ALADIN spectrometer at GSI. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. RP Bauer, G (reprint author), GESELL SCHWERIONENFORSCH MBH,D-64220 DARMSTADT,GERMANY. NR 13 TC 18 Z9 18 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 FEB 21 PY 1997 VL 386 IS 2-3 BP 249 EP 253 DI 10.1016/S0168-9002(96)00883-2 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700005 ER PT J AU Liu, Y Bogacz, SA Cline, DB Wang, XJ AF Liu, Y Bogacz, SA Cline, DB Wang, XJ TI Micro-bunching diagnostics for inverse Cherenkov acceleration by coherent transition radiation SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID ELECTRON-BEAM; LASER AB Here, we propose an effective method to detect micro-bunching effects (10 fs bunch length), produced by the inverse Cherenkov acceleration (ICA) interaction, by using the coherent transition radiation (CTR) spectrum. The pre-bunching of initially energy modulated electron beam passing through a Hydrogen gas cell is studied via a Monte Carlo simulation code (STI), as well as in a space-charge dominated region by a multi-particle time domain tracking code (PARMELA). The results show that even in a strong space-charge dominated region the pre-bunching effect is still very pronounced. The ''erosion'' of bunching due to the space-charge defocusing ''washes out'' the final bunching peak only by about 10% (FWHM). The longitudinal distribution of a micro-bunched beam is Fourier analyzed to find the dominant harmonics contributing to the CTR. The CTR spectrum is calculated analytically for the ICA situation. A schematic of the experimental set up is also proposed. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. RP Liu, Y (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,CTR ADV ACCELERATORS,405 HILGARD AVE,LOS ANGELES,CA 90095, 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 21 PY 1997 VL 386 IS 2-3 BP 295 EP 300 DI 10.1016/S0168-9002(96)01210-7 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700010 ER PT J AU Bertoldi, M Green, DR Hagopian, V Marraffino, J Ronzhin, A Thomaston, J AF Bertoldi, M Green, DR Hagopian, V Marraffino, J Ronzhin, A Thomaston, J TI Scintillators in magnetic fields up to 20 T SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB Plastic scintillators and wavelength shifting fibers have been placed in magnetic fields of up to 20 T and the change in light yield measured. The light yield in scintillators increases at very low magnetic fields and continues to increase with increasing field until saturation at about 2 T The maximum increase is between 6% and 8%, depending on the plastic composition. This increase is due to the polymer and not due to the dyes (fluors) used in the scintillators. No change of light yield due to magnetic fields has been observed in wavelength shifting fibers. C1 FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. RP Bertoldi, M (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, 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 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 21 PY 1997 VL 386 IS 2-3 BP 301 EP 306 DI 10.1016/S0168-9002(96)01178-3 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700011 ER PT J AU Abt, I Ahmed, T Aid, S Andreev, V Andrieu, B Appuhn, RD Arnault, C Arpagaus, M Babaev, A Barwolff, H Ban, J Banas, E Baranov, P Barrelet, E Bartel, W Barth, M Bassler, U Basti, F Baynham, DE Baze, JM Beck, GA Beck, HP Bederede, D Behrend, HJ Beigbeder, C Belousov, A Berger, C Bergstein, H Bernard, R Bernardi, G Bernet, R Bernier, R Berthon, U BertrandCoremans, G Besanson, M Beyer, R Biasci, JC Biddulph, P Bidoli, V Binder, E Binko, P Bizot, JC Blobel, V Blouzon, F Blume, H Borras, K Boudry, V Bourdarios, C Brasse, F Braunschweig, W Breton, D Brettel, H Brisson, V Bruncko, D Brune, C Buchner, U Bungener, L Burger, J Busser, FW Buniatian, A Burke, S Burmeister, P Busata, A Buschhorn, G Campbell, AJ Carli, T Charles, F Charlet, M Chase, R Clarke, D Clegg, AB Colombo, M Commichau, V Connolly, JF Cornett, U Coughlan, JA Courau, A Cousinou, MC Coutures, C Coville, A Cozzika, G Cragg, DA Criegee, L Cronstrom, HI Cunliffe, NH Cvach, J Cyz, A Dagoret, S Dainton, JB Danilov, M Dann, AWE Darvill, D Dau, WD David, J David, M Day, RJ Deffur, E Delcourt, B DelBuono, L Descamps, F Devel, M Dewulf, JP DeRoeck, A Dingus, P Djidi, K Dollfus, C Dowell, JD Dreis, HB Drescher, A Dretzler, U Duboc, J Ducorps, A Dullmann, D Dunger, O Duhm, H Dulny, B Dupont, F Ebbinghaus, R Eberle, M Ebert, J Ebert, TR Eckerlin, G Edwards, BWH Efremenko, V Egli, S Eichenberger, S Eichler, R Eisele, F Eisenhandler, E Ellis, NN Ellison, RJ Elsen, E Epifantsev, A Erdmann, M Erdmann, W Ernst, G Evrard, E Falley, G Favart, L Fedotov, A Feeken, D Felst, R Feltesse, J Feng, ZY Fensome, IF Fent, J Ferencei, J Ferrarotto, F Finke, K Flamm, K Flauger, W Fleischer, M Flieser, M Flower, PS Flugge, G Fomenko, A Fominykh, B Forbush, M Formanek, J Foster, JM Franke, G Fretwurst, E Frochtenicht, W Fuhrmann, P Gabathuler, E Gabathuler, K Gadow, K Gamerdinger, K Garvey, J Gayler, J Gazo, E Gellrich, A Gennis, M Gensch, U Genzel, H Gerhards, R Geske, K Giesgen, I Gillespie, D Glasgow, W Godfrey, L Godlewski, J Goerlach, U Goerlich, L Gogitidze, N Goldberg, M Goodall, AM Gorelov, I Goritchev, P Gosset, L Grab, C Grassler, H Grassler, R Greenshaw, T Gregory, C Greif, H Grewe, M Grindhammer, G Gruber, A Gruber, C Gunther, S Haack, J Haguenauer, M Haidt, D Hajduk, L Hammer, D Hamon, O Hampel, M Handschuh, D Hangarter, K Hanlon, EM Hapke, M Harder, U Harjes, J Hartz, P Hatton, PE Haydar, R Haynes, WJ Heatherington, J Hedberg, V Hedgecock, CR Heinzelmann, G Henderson, RCW Henschel, H Herma, R Herynek, I Hildesheim, W Hill, P Hill, DL Hilton, CD Hladky, J Hoeger, KC Hopes, RB Horisberger, R Hrisoho, A Huber, J Huet, P Hufnagel, H Huot, N Huppert, JF Ibbotson, M Imbault, D Itterbeck, H Jabiol, MA Jacholkowska, A Jacobsson, C Jaffre, M Jansen, T Jean, P Jeanjean, J Jonsson, L Johannsen, K Johnson, DP Johnson, L Jovanovic, P Jung, H Kalmus, PIP Kant, D Kantel, G Karstensen, S Kasarian, S Kaschowitz, R Kasselmann, P Kathage, U Kaufmann, HH Kemmerling, G Kenyon, IR Kermiche, S Keuker, C Kiesling, C Klein, M Kleinwort, C Knies, G Ko, W Kobler, T Koch, J Kohler, T Kohne, J Kolander, M Kolanoski, H Kole, F Koll, J Kolya, SD Koppitz, B Korbel, V Korn, M Kostka, P Kotelnikov, SK Krasny, MW Krehbiel, H Krivan, F Krucker, D Kruger, U KrunerMarquis, U Kubantsev, M Kubenka, JP Kulper, T Kusel, HJ Kuster, H Kuhlen, M Kurca, T Kurzhofer, J Kuznik, B Laforge, B Lamarche, F Lander, R Landon, MPJ Lange, W Lange, W Langkau, R Lanius, P Laporte, JF Laptin, L Laskus, H Lebedev, A Lemler, M Lenhardt, U Leuschner, A Leverenz, C Levonian, S Lewin, D Ley, C Lindner, A Lindstrom, G Linsel, F Lipinski, J Liss, B Loch, P Lodge, AB Lohmander, H Lopez, GC Lottin, JP Lubimov, V Ludwig, K Luers, D Lugetski, N Lundberg, B Maeshima, K Magnussen, N Malinovski, E Mani, S Marage, P Marks, J Marshall, R Martens, J Martin, F Martin, G Martin, R Martyn, HU Martyniak, J Masbender, V Masson, S Mavroidis, A Maxfield, SJ McMahon, SJ Mehta, A Meier, K Meissner, J Mercer, D Merz, T Meyer, CA Meyer, H Meyer, J Mikocki, S Mills, JL Milone, V Mock, J Monnier, E Montes, B Moreau, F Moreels, J Morgan, B Morris, JV Morton, JM Muller, K Murin, P Murray, SA Nagovizin, V Naroska, B Naumann, T Nayman, P Nepeipivo, A Newman, P NewmanCoburn, D Newton, D Neyret, D Nguyen, HK Niebergall, F Niebuhr, C Nisius, R Novak, T Novakova, H Nowak, G Noyes, GW Nyberg, M Oberlack, H Obrock, U Olsson, JE Olszowska, J Orenstein, S OuldSaada, F Pailler, P Palanque, S Panaro, E Panitch, A Parey, JY Pascaud, C Patel, GD Patoux, A Paulot, C Pein, U Peppel, E Perez, E Perrodo, P Perus, A Peters, S Pharabod, JP Phillips, HT Phillips, JP Pichler, C Pieuchot, A Pimpl, W Pitzl, D Porrovecchio, A Prell, S Prosi, R Quehl, H Radel, G Raupach, F Rauschnabel, K Reboux, A Reimer, P Reinmuth, G Reinshagen, S Ribarics, P Riech, V Riedlberger, J Riege, H Riess, S Rietz, M Robertson, SM Robmann, P Ropnack, P Roosen, R Rosenbauer, K Rostovtsev, A Royon, C Rudge, A Ruter, K Rudowicz, M Ruffer, M Rusakov, S Rusinov, V Rybicki, K Sacton, J Sahlmann, N Sanchez, E Sankey, DPC Savitski, M Schacht, P Schiek, S Schirm, N Schleif, S Schleper, P vonSchlippe, W Schmidt, C Schmidt, D Schmidt, G Schmitz, W Schmucker, H Schroder, V Schutt, J Schuhmann, E Schulz, M Schwind, A Scobel, W Seehausen, U Sefkow, F Sell, R Seman, M Semenov, A Shatalov, P Shekelyan, V Sheviakov, I Shooshtari, H Shtarkov, LN Siegmon, G Siewert, U Sirois, Y Sirous, A Skillicorn, IO Skvaril, P Smirnov, P Smith, JR Smolik, L Sole, D Soloviev, Y Spalek, J Spitzer, H vonStaa, R Staeck, J Staroba, P Stastny, J Steenbock, M Stefan, P Steffen, P Steinberg, R Steiner, H Stella, B Stephens, K Stier, J Stiewe, J Stosslein, U Strachota, J Straumann, U Strowbridge, A Struczinski, W Sutton, JP Szkutnik, Z Tappern, G Tapprogge, S Taylor, RE Tchernyshov, V Tchudakov, V Thiebaux, C Thiele, K Thompson, G Thompson, RJ Tichomirov, I Trenkel, C Tribanek, W Troger, K Truol, P Turiot, M Turnau, J Tutas, J Urban, L Urban, M Usik, A Valkar, S Valkarova, A Vallee, C VanBeek, G Vanderkelen, M VanLancker, L VanMechelen, P Vartapetian, A Vazdik, Y Vecko, M Verrecchia, P Vick, R Villet, G Vogel, E Wacker, K Wagener, M Walker, IW Walther, A Weber, G Wegener, D Wegner, A Weissbach, P Wellisch, HP West, L White, D Willard, S Winde, M Winter, GG Wolff, T Womersley, LA Wright, AE Wunsch, E Wulff, N Wyborn, BE Yiou, TP Zacek, J Zarbock, D Zavada, P Zeitnitz, C Zhang, Z Ziaeepour, H Zimmer, M Zimmermann, W Zomer, F Zuber, K AF Abt, I Ahmed, T Aid, S Andreev, V Andrieu, B Appuhn, RD Arnault, C Arpagaus, M Babaev, A Barwolff, H Ban, J Banas, E Baranov, P Barrelet, E Bartel, W Barth, M Bassler, U Basti, F Baynham, DE Baze, JM Beck, GA Beck, HP Bederede, D Behrend, HJ Beigbeder, C Belousov, A Berger, C Bergstein, H Bernard, R Bernardi, G Bernet, R Bernier, R Berthon, U BertrandCoremans, G Besanson, M Beyer, R Biasci, JC Biddulph, P Bidoli, V Binder, E Binko, P Bizot, JC Blobel, V Blouzon, F Blume, H Borras, K Boudry, V Bourdarios, C Brasse, F Braunschweig, W Breton, D Brettel, H Brisson, V Bruncko, D Brune, C Buchner, U Bungener, L Burger, J Busser, FW Buniatian, A Burke, S Burmeister, P Busata, A Buschhorn, G Campbell, AJ Carli, T Charles, F Charlet, M Chase, R Clarke, D Clegg, AB Colombo, M Commichau, V Connolly, JF Cornett, U Coughlan, JA Courau, A Cousinou, MC Coutures, C Coville, A Cozzika, G Cragg, DA Criegee, L Cronstrom, HI Cunliffe, NH Cvach, J Cyz, A Dagoret, S Dainton, JB Danilov, M Dann, AWE Darvill, D Dau, WD David, J David, M Day, RJ Deffur, E Delcourt, B DelBuono, L Descamps, F Devel, M Dewulf, JP DeRoeck, A Dingus, P Djidi, K Dollfus, C Dowell, JD Dreis, HB Drescher, A Dretzler, U Duboc, J Ducorps, A Dullmann, D Dunger, O Duhm, H Dulny, B Dupont, F Ebbinghaus, R Eberle, M Ebert, J Ebert, TR Eckerlin, G Edwards, BWH Efremenko, V Egli, S Eichenberger, S Eichler, R Eisele, F Eisenhandler, E Ellis, NN Ellison, RJ Elsen, E Epifantsev, A Erdmann, M Erdmann, W Ernst, G Evrard, E Falley, G Favart, L Fedotov, A Feeken, D Felst, R Feltesse, J Feng, ZY Fensome, IF Fent, J Ferencei, J Ferrarotto, F Finke, K Flamm, K Flauger, W Fleischer, M Flieser, M Flower, PS Flugge, G Fomenko, A Fominykh, B Forbush, M Formanek, J Foster, JM Franke, G Fretwurst, E Frochtenicht, W Fuhrmann, P Gabathuler, E Gabathuler, K Gadow, K Gamerdinger, K Garvey, J Gayler, J Gazo, E Gellrich, A Gennis, M Gensch, U Genzel, H Gerhards, R Geske, K Giesgen, I Gillespie, D Glasgow, W Godfrey, L Godlewski, J Goerlach, U Goerlich, L Gogitidze, N Goldberg, M Goodall, AM Gorelov, I Goritchev, P Gosset, L Grab, C Grassler, H Grassler, R Greenshaw, T Gregory, C Greif, H Grewe, M Grindhammer, G Gruber, A Gruber, C Gunther, S Haack, J Haguenauer, M Haidt, D Hajduk, L Hammer, D Hamon, O Hampel, M Handschuh, D Hangarter, K Hanlon, EM Hapke, M Harder, U Harjes, J Hartz, P Hatton, PE Haydar, R Haynes, WJ Heatherington, J Hedberg, V Hedgecock, CR Heinzelmann, G Henderson, RCW Henschel, H Herma, R Herynek, I Hildesheim, W Hill, P Hill, DL Hilton, CD Hladky, J Hoeger, KC Hopes, RB Horisberger, R Hrisoho, A Huber, J Huet, P Hufnagel, H Huot, N Huppert, JF Ibbotson, M Imbault, D Itterbeck, H Jabiol, MA Jacholkowska, A Jacobsson, C Jaffre, M Jansen, T Jean, P Jeanjean, J Jonsson, L Johannsen, K Johnson, DP Johnson, L Jovanovic, P Jung, H Kalmus, PIP Kant, D Kantel, G Karstensen, S Kasarian, S Kaschowitz, R Kasselmann, P Kathage, U Kaufmann, HH Kemmerling, G Kenyon, IR Kermiche, S Keuker, C Kiesling, C Klein, M Kleinwort, C Knies, G Ko, W Kobler, T Koch, J Kohler, T Kohne, J Kolander, M Kolanoski, H Kole, F Koll, J Kolya, SD Koppitz, B Korbel, V Korn, M Kostka, P Kotelnikov, SK Krasny, MW Krehbiel, H Krivan, F Krucker, D Kruger, U KrunerMarquis, U Kubantsev, M Kubenka, JP Kulper, T Kusel, HJ Kuster, H Kuhlen, M Kurca, T Kurzhofer, J Kuznik, B Laforge, B Lamarche, F Lander, R Landon, MPJ Lange, W Lange, W Langkau, R Lanius, P Laporte, JF Laptin, L Laskus, H Lebedev, A Lemler, M Lenhardt, U Leuschner, A Leverenz, C Levonian, S Lewin, D Ley, C Lindner, A Lindstrom, G Linsel, F Lipinski, J Liss, B Loch, P Lodge, AB Lohmander, H Lopez, GC Lottin, JP Lubimov, V Ludwig, K Luers, D Lugetski, N Lundberg, B Maeshima, K Magnussen, N Malinovski, E Mani, S Marage, P Marks, J Marshall, R Martens, J Martin, F Martin, G Martin, R Martyn, HU Martyniak, J Masbender, V Masson, S Mavroidis, A Maxfield, SJ McMahon, SJ Mehta, A Meier, K Meissner, J Mercer, D Merz, T Meyer, CA Meyer, H Meyer, J Mikocki, S Mills, JL Milone, V Mock, J Monnier, E Montes, B Moreau, F Moreels, J Morgan, B Morris, JV Morton, JM Muller, K Murin, P Murray, SA Nagovizin, V Naroska, B Naumann, T Nayman, P Nepeipivo, A Newman, P NewmanCoburn, D Newton, D Neyret, D Nguyen, HK Niebergall, F Niebuhr, C Nisius, R Novak, T Novakova, H Nowak, G Noyes, GW Nyberg, M Oberlack, H Obrock, U Olsson, JE Olszowska, J Orenstein, S OuldSaada, F Pailler, P Palanque, S Panaro, E Panitch, A Parey, JY Pascaud, C Patel, GD Patoux, A Paulot, C Pein, U Peppel, E Perez, E Perrodo, P Perus, A Peters, S Pharabod, JP Phillips, HT Phillips, JP Pichler, C Pieuchot, A Pimpl, W Pitzl, D Porrovecchio, A Prell, S Prosi, R Quehl, H Radel, G Raupach, F Rauschnabel, K Reboux, A Reimer, P Reinmuth, G Reinshagen, S Ribarics, P Riech, V Riedlberger, J Riege, H Riess, S Rietz, M Robertson, SM Robmann, P Ropnack, P Roosen, R Rosenbauer, K Rostovtsev, A Royon, C Rudge, A Ruter, K Rudowicz, M Ruffer, M Rusakov, S Rusinov, V Rybicki, K Sacton, J Sahlmann, N Sanchez, E Sankey, DPC Savitski, M Schacht, P Schiek, S Schirm, N Schleif, S Schleper, P vonSchlippe, W Schmidt, C Schmidt, D Schmidt, G Schmitz, W Schmucker, H Schroder, V Schutt, J Schuhmann, E Schulz, M Schwind, A Scobel, W Seehausen, U Sefkow, F Sell, R Seman, M Semenov, A Shatalov, P Shekelyan, V Sheviakov, I Shooshtari, H Shtarkov, LN Siegmon, G Siewert, U Sirois, Y Sirous, A Skillicorn, IO Skvaril, P Smirnov, P Smith, JR Smolik, L Sole, D Soloviev, Y Spalek, J Spitzer, H vonStaa, R Staeck, J Staroba, P Stastny, J Steenbock, M Stefan, P Steffen, P Steinberg, R Steiner, H Stella, B Stephens, K Stier, J Stiewe, J Stosslein, U Strachota, J Straumann, U Strowbridge, A Struczinski, W Sutton, JP Szkutnik, Z Tappern, G Tapprogge, S Taylor, RE Tchernyshov, V Tchudakov, V Thiebaux, C Thiele, K Thompson, G Thompson, RJ Tichomirov, I Trenkel, C Tribanek, W Troger, K Truol, P Turiot, M Turnau, J Tutas, J Urban, L Urban, M Usik, A Valkar, S Valkarova, A Vallee, C VanBeek, G Vanderkelen, M VanLancker, L VanMechelen, P Vartapetian, A Vazdik, Y Vecko, M Verrecchia, P Vick, R Villet, G Vogel, E Wacker, K Wagener, M Walker, IW Walther, A Weber, G Wegener, D Wegner, A Weissbach, P Wellisch, HP West, L White, D Willard, S Winde, M Winter, GG Wolff, T Womersley, LA Wright, AE Wunsch, E Wulff, N Wyborn, BE Yiou, TP Zacek, J Zarbock, D Zavada, P Zeitnitz, C Zhang, Z Ziaeepour, H Zimmer, M Zimmermann, W Zomer, F Zuber, K TI The H1 detector at HERA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Review ID DEEP INELASTIC-SCATTERING; SCINTILLATING-FIBER CALORIMETER; PROTON STRUCTURE FUNCTIONS; FIRST-LEVEL TRIGGER; MUON SCATTERING; CM ENERGIES; HIGH Q2; SYSTEM; COLLIDER; READOUT AB General aspects of the H1 detector at the electron-proton storage ring HERA as well as technical descriptions of the magnet, luminosity system, trigger, slow-control, data acquisition and off-line data handling are given. The three major components of the detector, the tracking, calorimeter and muon detectors, will be described in a forthcoming article. The present paper describes the detector that was used from 1992 to the end of 1994. After this a major upgrade of some components was undertaken. Some performance figures from luminosity runs at HERA during 1993 and 1994 are given. C1 CE SACLAY, CEA, DSM, DAPNIA, GIF SUR YVETTE, FRANCE. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-5100 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-5100 AACHEN, GERMANY. HUMBOLDT UNIV BERLIN, INST PHYS, BERLIN, GERMANY. UNIV BIRMINGHAM, SCH PHYS & SPACE RES, BIRMINGHAM, AL USA. VUB, ULB, INTERUNIV INST HIGH ENERGIES, BRUSSELS, BELGIUM. UNIV INSTELLING ANTWERP, B-2610 WILRIJK, BELGIUM. RUTHERFORD APPLETON LAB, CHILTON, ENGLAND. INST PHYS NUCL, KRAKOW, POLAND. UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. UNIV CALIF DAVIS, IIRPA, DAVIS, CA 95616 USA. UNIV DORTMUND, INST PHYS, D-4600 DORTMUND, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW, LANARK, SCOTLAND. DESY, D-2000 HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 2, D-2000 HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 1, D-2000 HAMBURG, GERMANY. UNIV HEIDELBERG, INST PHYS, D-6900 HEIDELBERG, GERMANY. UNIV HEIDELBERG, INST HOCHENERGIEPHYS, D-6900 HEIDELBERG, GERMANY. CHRISTIAN ALBRECHTS UNIV KIEL, INST REINE & ANGEW KERNPHYS, D-2300 KIEL, GERMANY. SLOVAK ACAD SCI, INST EXPT PHYS, KOSICE 04353, SLOVAKIA. UNIV LANCASTER, SCH PHYS & CHEM, LANCASTER, ENGLAND. UNIV LIVERPOOL, DEPT PHYS, LIVERPOOL L69 3BX, MERSEYSIDE, ENGLAND. UNIV LONDON QUEEN MARY & WESTFIELD COLL, LONDON E1 4NS, ENGLAND. LUND UNIV, DEPT PHYS, LUND, SWEDEN. UNIV MANCHESTER, DEPT PHYS, MANCHESTER M13 9PL, LANCS, ENGLAND. UNIV AIX MARSEILLE 2, CPPM, IN2P3, CNRS, F-13284 MARSEILLE 07, FRANCE. INST THEORET & EXPT PHYS, MOSCOW, RUSSIA. PN LEBEDEV PHYS INST, MOSCOW 117924, RUSSIA. MAX PLANCK INST PHYS & ASTROPHYS, D-80805 MUNICH, GERMANY. UNIV PARIS 11, LAL, IN2P3, CNRS, ORSAY, FRANCE. ECOLE POLYTECH, LPNHE, IN2P3, CNRS, PALAISEAU, FRANCE. UNIV PARIS 06, LPNHE, IN2P3, CNRS, PARIS, FRANCE. UNIV PARIS 07, LPNHE, IN2P3, CNRS, PARIS, FRANCE. ACAD SCI CZECH REPUBL, INST PHYS, PRAGUE, CZECH REPUBLIC. CHARLES UNIV, NUCL CTR, PRAGUE, CZECH REPUBLIC. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, ROME, ITALY. IST NAZL FIS NUCL, ROME, ITALY. PAUL SCHERRER INST, VILLIGEN, SWITZERLAND. BERG UNIV GESAMTHSCH WUPPERTAL, FACHBEREICH PHYS, WUPPERTAL, GERMANY. DESY, INST HOCHENERGIEPHYS, ZEUTHEN, GERMANY. ETH ZURICH, INST TEILCHENPHYS, ZURICH, SWITZERLAND. UNIV ZURICH, INST PHYS, ZURICH, SWITZERLAND. STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. RI Andreev, Vladimir/M-8665-2015; Fomenko, Alexander/I-7900-2014; Malinovski, Evgenii/N-1034-2015; Lebedev, Andrey/M-9710-2015; Gogitidze, Nelli/N-1224-2015; Belousov, Anatoli/N-2102-2015; Vazdik, Iakov/N-2624-2015; Szkutnik, Zbigniew/B-2214-2014; Staroba, Pavel/G-8850-2014; DEVEL, Michel/A-5677-2009; Meyer, Curtis/L-3488-2014; Levonian, Sergey/M-8693-2015; Soloviev, Yury/M-8788-2015; Gorelov, Igor/J-9010-2015; Sheviakov, Igor/N-2735-2015; Danilov, Mikhail/C-5380-2014; Kotelnikov, Sergey/A-9711-2014; Cvach, Jaroslav/G-6269-2014; OI DEVEL, Michel/0000-0001-8785-6896; Meyer, Curtis/0000-0001-7599-3973; Soloviev, Yury/0000-0003-1136-2827; Gorelov, Igor/0000-0001-5570-0133; Sheviakov, Igor/0000-0002-1659-3483; Danilov, Mikhail/0000-0001-9227-5164; Kotelnikov, Sergey/0000-0002-8027-4612; Erdmann, Martin/0000-0002-1653-1303; Beck, Hans Peter/0000-0001-7212-1096; Bassler, Ursula/0000-0002-9041-3057 NR 132 TC 319 Z9 319 U1 1 U2 8 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 FEB 21 PY 1997 VL 386 IS 2-3 BP 310 EP 347 DI 10.1016/S0168-9002(96)00893-5 PG 38 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700013 ER PT J AU Abt, I Ahmed, T Aid, S Andreev, V Andrieu, B Appuhn, RD Arnault, C Arpagaus, M Babaev, A Barwolff, H Ban, J Banas, E Baranov, P Barrelet, E Bartel, W Barth, M Bassler, U Basti, F Baynham, DE Baze, JM Beck, GA Beck, HP Bederede, D Behrend, HJ Beigbeder, C Belousov, A Berger, C Bergstein, H Bernard, R Bernardi, G Bernet, R Bernier, R Berthon, U BertrandCoremans, G Besancon, M Beyer, R Biasci, JC Biddulph, P Bidoli, V Binder, E Binko, P Bizot, JC Blobel, V Blouzon, F Blume, H Borras, K Boudry, V Bourdarios, C Brasse, F Braunschweig, W Breton, D Brettel, H Brisson, V Bruncko, D Brune, C Buchner, U Bungener, L Burger, J Busser, FW Buniatian, A Burke, S Burmeister, P Busata, A Buschhorn, G Campbell, AJ Carli, T Charles, F Charlet, M Chase, R Clarke, D Clegg, AB Colombo, M Commichau, V Connolly, JF Cornett, U Coughlan, JA Courau, A Cousinou, MC Coutures, C Coville, A Cozzika, G Cragg, DA Criegee, L Cronstrom, HI Cunliffe, NH Cvach, J Cyz, A Dagoret, S Dainton, JB Danilov, M Dann, AWE Darvill, D Dau, WD David, J David, M Day, RJ Deffur, E Delcourt, B DelBuono, L Descamps, F Devel, M Dewulf, JP DeRoeck, A Dingus, P Djidi, K Dollfus, C Dowell, JD Dreis, HB Drescher, A Dretzler, U Duboc, J Ducorps, A Dullmann, D Dunger, O Duhm, H Dulny, B Dupont, F Ebbinghaus, R Eberle, M Ebert, J Ebert, TR Eckerlin, G Edwards, BWH Efremenko, V Egli, S Eichenberger, S Eichler, R Eisele, F Eisenhandler, E Ellis, NN Ellison, RJ Elsen, E Epifantsev, A Erdmann, M Erdmann, W Ernst, G Evrard, E Falley, G Favart, L Fedotov, A Feeken, D Felst, R Feltesse, J Feng, ZY Fensome, IF Fent, J Ferencei, J Ferrarotto, F Finke, K Flamm, K Flauger, W Fleischer, M Flieser, M Flower, PS Flugge, G Fomenko, A Fominykh, B Forbush, M Formanek, J Foster, JL Franke, G Fretwurst, E Frochtenicht, W Fuhrmann, P Gabathuler, E Gabathuler, K Gadow, K Gamerdinger, K Garvey, J Gayler, J Gazo, E Gellrich, A Gennis, M Gensch, U Genzel, H Gerhards, R Geske, K Giesgen, I Gillespie, D Glasgow, W Godfrey, L Godlewski, J Goerlach, U Goerlich, L Gogitidze, N Goldberg, M Goodall, AM Gorelov, I Goritchev, P Gosset, L Grab, C Grassler, H Grassler, R Greenshaw, T Gregory, C Greif, H Grewe, M Grindhammer, G Gruber, A Gruber, C Gunther, S Haack, J Haguenauer, M Haidt, D Hajduk, L Hammer, D Hamon, O Hampel, M Handschuh, D Hangarter, K Hanlon, EM Hapke, M Harder, U Harjes, J Hartz, P Hatton, PE Haydar, R Haynes, WJ Heatherington, J Hedberg, V Hedgecock, CR Heinzelmann, G Henderson, RCW Henschel, H Herma, R Herynek, I Hildesheim, W Hill, P Hill, DL Hilton, CD Hladky, J Hoeger, KC Hopes, RB Horisberger, R Hrisoho, A Huber, J Huet, P Hufnagel, H Huot, N Huppert, JF Ibbotson, M Imbault, D Itterbeck, H Jabiol, MA Jacholkowska, A Jacobsson, C Jaffre, M Janoth, J Jansen, T Jean, P Jeanjean, J Jonsson, L Johannsen, K Johnson, DP Johnson, L Jovanovic, P Jung, H Kalmus, PIP Kant, D Kantel, G Karstensen, S Kasarian, S Kaschowitz, R Kasselmann, P Kathage, U Kaufmann, HH Kemmerling, G Kenyon, IR Kermiche, S Keuker, C Kiesling, C Klein, M Kleinwort, C Knies, G Ko, W Kobler, T Koch, J Kohler, T Kohne, J Kolander, M Kolanoski, H Kole, F Koll, J Kolya, SD Koppitz, B Korbel, V Korn, M Kostka, P Kotelnikov, SK Krasny, MW Krehbiel, H Krivan, F Krucker, D Kruger, U KrunerMarquis, U Kubantsev, M Kubenka, JP Kulper, T Kusel, HJ Kuster, H Kuhlen, M Kurca, T Kurzhofer, J Kuznik, B Laforge, B Lamarche, F Lander, R Landon, MPJ Lange, W Lange, W Langkau, R Lanius, P Laporte, JF Laptin, L Laskus, H Lebedev, A Lemler, M Lenhardt, U Leuschner, A Leverenz, C Levonian, S Lewin, D Ley, C Lindner, A Lindstrom, G Linsel, F Lipinski, J Liss, B Loch, P Lodge, AB Lohmander, H Lopez, GC Lottin, JP Lubimov, V Ludwig, K Luers, D Lugetski, N Lundberg, B Maeshima, K Magnussen, N Malinovski, E Mani, S Marage, P Marks, J Marshall, R Martens, J Martin, F Martin, G Martin, R Martyn, HU Martyniak, J Masbender, V Masson, S Mavroidis, A Maxfield, SJ McMahon, SJ Mehta, A Meier, K Meissner, J Mercer, D Merz, T Meyer, CA Meyer, H Meyer, J Mikocki, S Mills, JL Milone, V Mock, J Monnier, E Montes, B Moreau, F Moreels, J Morgan, B Morris, JV Morton, JM Muller, K Murin, P Murray, SA Nagovizin, V Naroska, B Naumann, T Nayman, P Nepeipivo, A Newman, P NewmanCoburn, D Newton, D Neyret, D Nguyen, HK Niebergall, F Niebuhr, C Nisius, R Novak, T Novakova, H Nowak, G Noyes, GW Nyberg, M Oberlack, H Obrock, U Olsson, JE Olszowska, J Orenstein, S OuldSaada, F Pailler, P Palanque, S Panaro, S Panitch, A Parey, JY Pascaud, C Patel, GD Patoux, A Paulot, C Pein, U Peppel, E Perez, E Perrodo, P Perus, A Peters, S Pharabod, JP Phillips, HT Phillips, JP Pichler, C Pieuchot, A Pimpl, W Pitzl, D Porrovecchio, A Prell, S Prosi, R Quehl, H Radel, G Raupach, F Rauschnabel, K Reboux, A Reimer, P Reinmuth, G Reinshagen, S Ribarics, P Riech, V Riedlberger, J Riege, H Riess, S Rietz, M Robertson, SM Robmann, P Ropnack, P Roosen, R Rosenbauer, K Rostovtsev, A Royon, C Rudge, A Ruter, K Rudowicz, M Ruffer, M Rusakov, S Rusinov, V Rybicki, K Sacton, J Sahlmann, N Sanchez, E Sankey, DPC Savitski, M Schacht, P Schiek, S Schirm, N Schleif, S Schleper, P vonSchlippe, W Schmidt, C Schmidt, D Schmidt, G Schmitz, W Schmucker, H Schroder, V Schutt, J Schuhmann, E Schulz, M Schwind, A Scobel, W Seehausen, U Sefkow, F Sell, R Seman, M Semenov, A Shatalov, P Shekelyan, V Sheviakov, I Shooshtari, H Shtarkov, LN Siegmon, G Siewert, U Sirois, Y Sirous, A Skillicorn, IO Skvaril, P Smirnov, P Smith, JR Smolik, L Sole, D Soloviev, Y Spalek, J Spitzer, H vonStaa, R Staeck, J Staroba, P Stastny, J Steenbock, M Stefan, P Steffen, P Steinberg, R Steiner, H Stella, B Stephens, K Stier, J Stiewe, J Stosslein, U Strachota, J Straumann, U Strowbridge, A Struczinski, W Sutton, JP Szkutnik, Z Tappern, G Tapprogge, S Taylor, RE Tchernyshov, V Tchudakov, V Thiebaux, C Thiele, K Thompson, G Thompson, RJ Tichomirov, I Trenkel, C Tribanek, W Troger, K Truol, P Turiot, M Turnau, J Tutas, J Urban, L Urban, M Usik, A Valkar, S Valkarova, A Vallee, C VanBeek, G Vanderkelen, M VanLancker, L VanMechelen, P Vartapetian, A Vazdik, Y Vecko, M Verrecchia, P Vick, R Villet, G Vogel, E Wacker, A Wagener, M Walker, IW Walther, A Weber, G Wegener, D Wegner, A Weissbach, P Wellisch, HP West, L White, D Willard, S Winde, M Winter, GG Wolff, T Womersley, LA Wright, AE Wunsch, E Wulff, N Wyborn, BE Yiou, TP Zacek, J Zarbock, D Zavada, P Zeitnitz, C Zhang, Z Ziaeepour, H Zimmmer, M Zimmermann, W Zomer, F Zuber, K AF Abt, I Ahmed, T Aid, S Andreev, V Andrieu, B Appuhn, RD Arnault, C Arpagaus, M Babaev, A Barwolff, H Ban, J Banas, E Baranov, P Barrelet, E Bartel, W Barth, M Bassler, U Basti, F Baynham, DE Baze, JM Beck, GA Beck, HP Bederede, D Behrend, HJ Beigbeder, C Belousov, A Berger, C Bergstein, H Bernard, R Bernardi, G Bernet, R Bernier, R Berthon, U BertrandCoremans, G Besancon, M Beyer, R Biasci, JC Biddulph, P Bidoli, V Binder, E Binko, P Bizot, JC Blobel, V Blouzon, F Blume, H Borras, K Boudry, V Bourdarios, C Brasse, F Braunschweig, W Breton, D Brettel, H Brisson, V Bruncko, D Brune, C Buchner, U Bungener, L Burger, J Busser, FW Buniatian, A Burke, S Burmeister, P Busata, A Buschhorn, G Campbell, AJ Carli, T Charles, F Charlet, M Chase, R Clarke, D Clegg, AB Colombo, M Commichau, V Connolly, JF Cornett, U Coughlan, JA Courau, A Cousinou, MC Coutures, C Coville, A Cozzika, G Cragg, DA Criegee, L Cronstrom, HI Cunliffe, NH Cvach, J Cyz, A Dagoret, S Dainton, JB Danilov, M Dann, AWE Darvill, D Dau, WD David, J David, M Day, RJ Deffur, E Delcourt, B DelBuono, L Descamps, F Devel, M Dewulf, JP DeRoeck, A Dingus, P Djidi, K Dollfus, C Dowell, JD Dreis, HB Drescher, A Dretzler, U Duboc, J Ducorps, A Dullmann, D Dunger, O Duhm, H Dulny, B Dupont, F Ebbinghaus, R Eberle, M Ebert, J Ebert, TR Eckerlin, G Edwards, BWH Efremenko, V Egli, S Eichenberger, S Eichler, R Eisele, F Eisenhandler, E Ellis, NN Ellison, RJ Elsen, E Epifantsev, A Erdmann, M Erdmann, W Ernst, G Evrard, E Falley, G Favart, L Fedotov, A Feeken, D Felst, R Feltesse, J Feng, ZY Fensome, IF Fent, J Ferencei, J Ferrarotto, F Finke, K Flamm, K Flauger, W Fleischer, M Flieser, M Flower, PS Flugge, G Fomenko, A Fominykh, B Forbush, M Formanek, J Foster, JL Franke, G Fretwurst, E Frochtenicht, W Fuhrmann, P Gabathuler, E Gabathuler, K Gadow, K Gamerdinger, K Garvey, J Gayler, J Gazo, E Gellrich, A Gennis, M Gensch, U Genzel, H Gerhards, R Geske, K Giesgen, I Gillespie, D Glasgow, W Godfrey, L Godlewski, J Goerlach, U Goerlich, L Gogitidze, N Goldberg, M Goodall, AM Gorelov, I Goritchev, P Gosset, L Grab, C Grassler, H Grassler, R Greenshaw, T Gregory, C Greif, H Grewe, M Grindhammer, G Gruber, A Gruber, C Gunther, S Haack, J Haguenauer, M Haidt, D Hajduk, L Hammer, D Hamon, O Hampel, M Handschuh, D Hangarter, K Hanlon, EM Hapke, M Harder, U Harjes, J Hartz, P Hatton, PE Haydar, R Haynes, WJ Heatherington, J Hedberg, V Hedgecock, CR Heinzelmann, G Henderson, RCW Henschel, H Herma, R Herynek, I Hildesheim, W Hill, P Hill, DL Hilton, CD Hladky, J Hoeger, KC Hopes, RB Horisberger, R Hrisoho, A Huber, J Huet, P Hufnagel, H Huot, N Huppert, JF Ibbotson, M Imbault, D Itterbeck, H Jabiol, MA Jacholkowska, A Jacobsson, C Jaffre, M Janoth, J Jansen, T Jean, P Jeanjean, J Jonsson, L Johannsen, K Johnson, DP Johnson, L Jovanovic, P Jung, H Kalmus, PIP Kant, D Kantel, G Karstensen, S Kasarian, S Kaschowitz, R Kasselmann, P Kathage, U Kaufmann, HH Kemmerling, G Kenyon, IR Kermiche, S Keuker, C Kiesling, C Klein, M Kleinwort, C Knies, G Ko, W Kobler, T Koch, J Kohler, T Kohne, J Kolander, M Kolanoski, H Kole, F Koll, J Kolya, SD Koppitz, B Korbel, V Korn, M Kostka, P Kotelnikov, SK Krasny, MW Krehbiel, H Krivan, F Krucker, D Kruger, U KrunerMarquis, U Kubantsev, M Kubenka, JP Kulper, T Kusel, HJ Kuster, H Kuhlen, M Kurca, T Kurzhofer, J Kuznik, B Laforge, B Lamarche, F Lander, R Landon, MPJ Lange, W Lange, W Langkau, R Lanius, P Laporte, JF Laptin, L Laskus, H Lebedev, A Lemler, M Lenhardt, U Leuschner, A Leverenz, C Levonian, S Lewin, D Ley, C Lindner, A Lindstrom, G Linsel, F Lipinski, J Liss, B Loch, P Lodge, AB Lohmander, H Lopez, GC Lottin, JP Lubimov, V Ludwig, K Luers, D Lugetski, N Lundberg, B Maeshima, K Magnussen, N Malinovski, E Mani, S Marage, P Marks, J Marshall, R Martens, J Martin, F Martin, G Martin, R Martyn, HU Martyniak, J Masbender, V Masson, S Mavroidis, A Maxfield, SJ McMahon, SJ Mehta, A Meier, K Meissner, J Mercer, D Merz, T Meyer, CA Meyer, H Meyer, J Mikocki, S Mills, JL Milone, V Mock, J Monnier, E Montes, B Moreau, F Moreels, J Morgan, B Morris, JV Morton, JM Muller, K Murin, P Murray, SA Nagovizin, V Naroska, B Naumann, T Nayman, P Nepeipivo, A Newman, P NewmanCoburn, D Newton, D Neyret, D Nguyen, HK Niebergall, F Niebuhr, C Nisius, R Novak, T Novakova, H Nowak, G Noyes, GW Nyberg, M Oberlack, H Obrock, U Olsson, JE Olszowska, J Orenstein, S OuldSaada, F Pailler, P Palanque, S Panaro, S Panitch, A Parey, JY Pascaud, C Patel, GD Patoux, A Paulot, C Pein, U Peppel, E Perez, E Perrodo, P Perus, A Peters, S Pharabod, JP Phillips, HT Phillips, JP Pichler, C Pieuchot, A Pimpl, W Pitzl, D Porrovecchio, A Prell, S Prosi, R Quehl, H Radel, G Raupach, F Rauschnabel, K Reboux, A Reimer, P Reinmuth, G Reinshagen, S Ribarics, P Riech, V Riedlberger, J Riege, H Riess, S Rietz, M Robertson, SM Robmann, P Ropnack, P Roosen, R Rosenbauer, K Rostovtsev, A Royon, C Rudge, A Ruter, K Rudowicz, M Ruffer, M Rusakov, S Rusinov, V Rybicki, K Sacton, J Sahlmann, N Sanchez, E Sankey, DPC Savitski, M Schacht, P Schiek, S Schirm, N Schleif, S Schleper, P vonSchlippe, W Schmidt, C Schmidt, D Schmidt, G Schmitz, W Schmucker, H Schroder, V Schutt, J Schuhmann, E Schulz, M Schwind, A Scobel, W Seehausen, U Sefkow, F Sell, R Seman, M Semenov, A Shatalov, P Shekelyan, V Sheviakov, I Shooshtari, H Shtarkov, LN Siegmon, G Siewert, U Sirois, Y Sirous, A Skillicorn, IO Skvaril, P Smirnov, P Smith, JR Smolik, L Sole, D Soloviev, Y Spalek, J Spitzer, H vonStaa, R Staeck, J Staroba, P Stastny, J Steenbock, M Stefan, P Steffen, P Steinberg, R Steiner, H Stella, B Stephens, K Stier, J Stiewe, J Stosslein, U Strachota, J Straumann, U Strowbridge, A Struczinski, W Sutton, JP Szkutnik, Z Tappern, G Tapprogge, S Taylor, RE Tchernyshov, V Tchudakov, V Thiebaux, C Thiele, K Thompson, G Thompson, RJ Tichomirov, I Trenkel, C Tribanek, W Troger, K Truol, P Turiot, M Turnau, J Tutas, J Urban, L Urban, M Usik, A Valkar, S Valkarova, A Vallee, C VanBeek, G Vanderkelen, M VanLancker, L VanMechelen, P Vartapetian, A Vazdik, Y Vecko, M Verrecchia, P Vick, R Villet, G Vogel, E Wacker, A Wagener, M Walker, IW Walther, A Weber, G Wegener, D Wegner, A Weissbach, P Wellisch, HP West, L White, D Willard, S Winde, M Winter, GG Wolff, T Womersley, LA Wright, AE Wunsch, E Wulff, N Wyborn, BE Yiou, TP Zacek, J Zarbock, D Zavada, P Zeitnitz, C Zhang, Z Ziaeepour, H Zimmmer, M Zimmermann, W Zomer, F Zuber, K TI The tracking, calorimeter and muon detectors of the H1 experiment at HERA SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Review ID LIQUID ARGON CALORIMETER; WIRE DRIFT CHAMBERS; H-1 EXPERIMENT; CONSTRUCTION; PERFORMANCE; RECONSTRUCTION; CALIBRATION; READOUT; PULSES; SYSTEM AB Technical aspects of the three major components of the H1 detector at the electron-proton storage ring HERA are described. This paper covers the detector status up to the end of 1994 when a major upgrading of some of its elements was undertaken. A description of the other elements of the detector and some performance figures from luminosity runs at HERA during 1993 and 1994 are given in a paper previously published in this journal. C1 CTR ETUD SACLAY, CEA, DSM DAPNIA, F-91191 GIF SUR YVETTE, FRANCE. RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-5100 AACHEN, GERMANY. RHEIN WESTFAL TH AACHEN, INST PHYS 3, D-5100 AACHEN, GERMANY. HUMBOLDT UNIV BERLIN, INST PHYS, BERLIN, GERMANY. UNIV BIRMINGHAM, SCH PHYS & SPACE RES, BIRMINGHAM B15 2TT, W MIDLANDS, ENGLAND. UNIV INSTELLING ANTWERP, WILRIJK, BELGIUM. ULB VUB, INTERUNIV INST HIGH ENERGIES, BRUSSELS, BELGIUM. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. INST NUCL PHYS, KRAKOW, POLAND. UNIV DORTMUND, INST PHYS, D-4600 DORTMUND, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW, LANARK, SCOTLAND. DESY, HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 2, D-2000 HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 1, D-2000 HAMBURG, GERMANY. UNIV HEIDELBERG, INST PHYS, D-6900 HEIDELBERG, GERMANY. UNIV HEIDELBERG, INST HOCHENERGIEPHYS, D-6900 HEIDELBERG, GERMANY. CHRISTIAN ALBRECHTS UNIV KIEL, INST REINE & ANGEW KERNPHYS, D-2300 KIEL, GERMANY. SLOVAK ACAD SCI, INST EXPT PHYS, KOSICE 04353, SLOVAKIA. UNIV LANCASTER, SCH PHYS & CHEM, LANCASTER, ENGLAND. UNIV LIVERPOOL, DEPT PHYS, LIVERPOOL L69 3BX, MERSEYSIDE, ENGLAND. UNIV LONDON QUEEN MARY & WESTFIELD COLL, LONDON E1 4NS, ENGLAND. LUND UNIV, DEPT PHYS, LUND, SWEDEN. UNIV MANCHESTER, DEPT PHYS, MANCHESTER M13 9PL, LANCS, ENGLAND. UNIV AIX MARSEILLE 2, CPPM, CNRS, IN2P3, F-13284 MARSEILLE 07, FRANCE. MOSCOW THEORET & EXPT PHYS INST, MOSCOW, RUSSIA. PN LEBEDEV PHYS INST, MOSCOW 117924, RUSSIA. MAX PLANCK INST PHYS & ASTROPHYS, D-80805 MUNICH, GERMANY. ECOLE POLYTECH, IN2P3, CNRS, LPNHE, PALAISEAU, FRANCE. UNIV PARIS 11, IN2P3, CNRS, LAL, ORSAY, FRANCE. UNIV PARIS 06&7, IN2P3, CNRS, LPNHE, PARIS, FRANCE. ACAD SCI CZECH REPUBL, INST PHYS, PRAGUE, CZECH REPUBLIC. CHARLES UNIV, NUCL CTR, PRAGUE, CZECH REPUBLIC. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. IST NAZL FIS NUCL, ROME, ITALY. PAUL SCHERRER INST, VILLIGEN, SWITZERLAND. BERG UNIV GESAMTHSCH WUPPERTAL, FACHBEREICH PHYS, WUPPERTAL, GERMANY. DESY, INST HOCHENERGIEPHYS, ZEUTHEN, GERMANY. ETH ZURICH, INST TEILCHENPHYS, ZURICH, SWITZERLAND. UNIV ZURICH, INST PHYS, ZURICH, SWITZERLAND. STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV CALIF DAVIS, DEPT PHYS, DAVIS, CA 95616 USA. UNIV CALIF DAVIS, IIRPA, DAVIS, CA 95616 USA. RI Gorelov, Igor/J-9010-2015; Sheviakov, Igor/N-2735-2015; Danilov, Mikhail/C-5380-2014; Kotelnikov, Sergey/A-9711-2014; Cvach, Jaroslav/G-6269-2014; Gogitidze, Nelli/N-1224-2015; Belousov, Anatoli/N-2102-2015; Szkutnik, Zbigniew/B-2214-2014; Staroba, Pavel/G-8850-2014; DEVEL, Michel/A-5677-2009; Meyer, Curtis/L-3488-2014; Levonian, Sergey/M-8693-2015; Soloviev, Yury/M-8788-2015; Andreev, Vladimir/M-8665-2015; Fomenko, Alexander/I-7900-2014; Malinovski, Evgenii/N-1034-2015; Lebedev, Andrey/M-9710-2015; Vazdik, Iakov/N-2624-2015 OI Gorelov, Igor/0000-0001-5570-0133; Sheviakov, Igor/0000-0002-1659-3483; Danilov, Mikhail/0000-0001-9227-5164; Kotelnikov, Sergey/0000-0002-8027-4612; Beck, Hans Peter/0000-0001-7212-1096; Bassler, Ursula/0000-0002-9041-3057; DEVEL, Michel/0000-0001-8785-6896; Meyer, Curtis/0000-0001-7599-3973; Soloviev, Yury/0000-0003-1136-2827; NR 102 TC 242 Z9 243 U1 0 U2 2 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 FEB 21 PY 1997 VL 386 IS 2-3 BP 348 EP 396 DI 10.1016/S0168-9002(96)00894-7 PG 49 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700014 ER PT J AU Appuhn, RD Arndt, C Barrelet, E Barschke, R Bassler, U Boudry, V Buchholz, R Brasse, F Bruncko, D Chechelnitski, S Claxton, B Cozzika, G Cvach, J DagoretCampagne, S Dau, WD Deckers, H Deckers, T Descamps, F Dirkmann, M Dowdell, J Efremenko, V Eisenhandler, E Eliseev, AN Falley, G Ferencei, J Fominykh, B Gadow, K Goerlach, U Gorbov, LA Gorelov, I Grewe, M Hajduk, L Herynek, I Hladky, J Hutte, M Hutter, H Janczur, W Janoth, J Jonsson, L Kolanoski, H Korbel, V Krivan, F Lacour, D Lamarche, F Landon, MPJ Laforge, B Laporte, JF Lehner, F Maracek, R Meier, K Meyer, A Migliori, A Moreau, F Muller, G Murin, P Nagovizin, V Nicholls, TC Ozerov, D Perez, E Pharabod, JP Poschl, R Rybicki, K Rostovtsev, A Royon, C Schleif, S Schuhmacher, A Semenov, A Shekelyan, V Sirois, Y Smirnov, PA Solochenko, V Spalek, J Spielmann, S Steiner, H Stiewe, J Tasevsky, M Tchernyshov, V Thiele, K Tzamariudaki, E Valkar, S VanDenPlas, D Villet, G Wacker, K Walther, A Weber, M Wegener, D Wenk, T Zacek, J Zhokin, A Zuber, K AF Appuhn, RD Arndt, C Barrelet, E Barschke, R Bassler, U Boudry, V Buchholz, R Brasse, F Bruncko, D Chechelnitski, S Claxton, B Cozzika, G Cvach, J DagoretCampagne, S Dau, WD Deckers, H Deckers, T Descamps, F Dirkmann, M Dowdell, J Efremenko, V Eisenhandler, E Eliseev, AN Falley, G Ferencei, J Fominykh, B Gadow, K Goerlach, U Gorbov, LA Gorelov, I Grewe, M Hajduk, L Herynek, I Hladky, J Hutte, M Hutter, H Janczur, W Janoth, J Jonsson, L Kolanoski, H Korbel, V Krivan, F Lacour, D Lamarche, F Landon, MPJ Laforge, B Laporte, JF Lehner, F Maracek, R Meier, K Meyer, A Migliori, A Moreau, F Muller, G Murin, P Nagovizin, V Nicholls, TC Ozerov, D Perez, E Pharabod, JP Poschl, R Rybicki, K Rostovtsev, A Royon, C Schleif, S Schuhmacher, A Semenov, A Shekelyan, V Sirois, Y Smirnov, PA Solochenko, V Spalek, J Spielmann, S Steiner, H Stiewe, J Tasevsky, M Tchernyshov, V Thiele, K Tzamariudaki, E Valkar, S VanDenPlas, D Villet, G Wacker, K Walther, A Weber, M Wegener, D Wenk, T Zacek, J Zhokin, A Zuber, K TI The H1 lead/scintillating-fibre calorimeter SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE calorimeter; fibre; construction; design; H1 ID SCINTILLATING-FIBER CALORIMETER; ELECTROMAGNETIC CALORIMETRY; SPAGHETTI CALORIMETER; PION; PROTOTYPE; ELECTRON AB The backward region of the H1 detector has been upgraded in order to provide improved measurement of the scattered electron in deep inelastic scattering events. The centerpiece of the upgrade is a high-resolution lead/scintillating-fibre calorimeter. The main design goals of the calorimeter are: good coverage of the region close to the beam pipe, high angular resolution and energy resolution of better than 2% for 30 GeV electrons. The calorimeter should be capable of providing coarse hadronic energy measurement and precise time information to suppress out-of-time background events at the first trigger level. It must be compact due to space restrictions. These requirements were fulfilled by constructing two separate calorimeter sections. The inner electromagnetic section is made of 0.5 mm scintillating plastic fibres embedded in a lead matrix. Its lead-to-fibre ratio is 2.3:1 by volume. The outer hadronic section consists of 1.0 mm diameter fibres with a lead-to-fibre ratio of 3:4:1. The mechanical construction of the new calorimeter and its assembly in the H1 detector are described. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. UNIV HEIDELBERG, INST HOCHENERGIEPHYS, HEIDELBERG, GERMANY. UNIV BIRMINGHAM, SCH PHYS & SPACE RES, BIRMINGHAM B15 2TT, W MIDLANDS, ENGLAND. UNIV DORTMUND, INST PHYS, D-4600 DORTMUND, GERMANY. CTR ETUD SACLAY, CEA, DSM DAPNIA, F-91191 GIF SUR YVETTE, FRANCE. DESY, HAMBURG, GERMANY. SLOVAK ACAD SCI, INST EXPT PHYS, KOSICE 04353, SLOVAKIA. UNIV LONDON QUEEN MARY & WESTFIELD COLL, LONDON E1 4NS, ENGLAND. INST THEORET & EXPT PHYS, MOSCOW 117259, RUSSIA. ECOLE POLYTECH, IN2P3, CNRS, LPNHE, PALAISEAU, FRANCE. UNIV PARIS 06&7, IN2P3, CNRS, LPNHE, PARIS, FRANCE. ACAD SCI CZECH REPUBL, INST PHYS, PRAGUE, CZECH REPUBLIC. CHARLES UNIV, NUCL CTR, PRAGUE, CZECH REPUBLIC. INST NUCL PHYS, KRAKOW, POLAND. RUTHERFORD APPLETON LAB, DIV ELECT, DIDCOT OX11 0QX, OXON, ENGLAND. CHRISTIAN ALBRECHTS UNIV KIEL, INST REINE & ANGEW KERNPHYS, D-2300 KIEL, GERMANY. LUND UNIV, DEPT PHYS, LUND, SWEDEN. PN LEBEDEV PHYS INST, MOSCOW 117924, RUSSIA. RI Gorelov, Igor/J-9010-2015; Ozerov, Dmitry/E-9139-2016; Cvach, Jaroslav/G-6269-2014 OI Gorelov, Igor/0000-0001-5570-0133; NR 41 TC 142 Z9 142 U1 0 U2 2 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 FEB 21 PY 1997 VL 386 IS 2-3 BP 397 EP 408 DI 10.1016/S0168-9002(96)01171-0 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700015 ER PT J AU Fabris, L Goulding, FS Madden, NW Manfredi, PF AF Fabris, L Goulding, FS Madden, NW Manfredi, PF TI Spreading resistance measurements in p-n junctions - A simple technique SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID SPECTROMETERS AB A simple technique to extract the location and value of parasitic series resistance in junction devices is discussed and an instrument which performs these measurements is described. Measurements of gate series resistance on several high figure of merit junction field-effect transistors are presented. The limitations in noise behavior due to this resistance are discussed. C1 UNIV PAVIA,DIPARTIMENTO ELETTR,I-27100 PAVIA,ITALY. RP Fabris, L (reprint author), LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. RI Fabris, Lorenzo/E-4653-2013 OI Fabris, Lorenzo/0000-0001-5605-5615 NR 7 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD FEB 21 PY 1997 VL 386 IS 2-3 BP 470 EP 473 DI 10.1016/S0168-9002(96)01208-9 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA WT227 UT WOS:A1997WT22700024 ER PT J AU Bau, R Drabnis, MH Garlaschelli, L Klooster, WT Xie, ZW Koetzle, TF Martinengo, S AF Bau, R Drabnis, MH Garlaschelli, L Klooster, WT Xie, ZW Koetzle, TF Martinengo, S TI Five-coordinate hydrogen: Neutron diffraction analysis of the hydrido cluster complex [H2Rh13(CO)(24)](3-) SO SCIENCE LA English DT Article ID CARBONYL CLUSTERS; X-RAY; DIRECT LOCATION; METAL-SURFACES; HE-DIFFRACTION; RHODIUM; ADSORPTION; (1X1)-2H; CRYSTAL; RH(110) AB Pentacoordinate hydrogen atoms were identified by single-crystal neutron diffraction analysis of [N(CH3)(4)](3)[H2Rh13(CO)(24)]. The hydrogen atoms are located in square pyramidal cavities of the Rh-13 cluster, in positions almost coplanar with the Rh-4 faces on the surface of the cluster. They are slightly displaced inward, toward the central rhodium atom of the cluster, with average H-Rh(central) and H-Rh(surface) distances of 1.84(2) and 1.97(2) angstroms, respectively. This result shows that hydrogen, which normally forms only one bond, can be attached to five other atoms simultaneously in a large metal cluster. C1 UNIV MILAN,DIPARTIMENTO CHIM INORGAN MET ORGAN & ANALYT,I-20133 MILAN,ITALY. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Bau, R (reprint author), UNIV SO CALIF,DEPT CHEM,LOS ANGELES,CA 90089, USA. RI Xie, Zuowei/A-5669-2010 NR 36 TC 39 Z9 40 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 FEB 21 PY 1997 VL 275 IS 5303 BP 1099 EP 1102 DI 10.1126/science.275.5303.1099 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ503 UT WOS:A1997WJ50300036 ER PT J AU Xu, XH Yeung, ES AF Xu, XH Yeung, ES TI Direct measurement of single-molecule diffusion and photodecomposition in free solution SO SCIENCE LA English DT Article ID LASER-INDUCED FLUORESCENCE; DNA-MOLECULES; MICRODROPLETS AB Continuous monitoring of submillisecond free-solution dynamics of individual rhodamine-6G molecules and 30-base single-stranded DNA tagged with rhodamine was achieved. Fluorescence images were recorded from the same set of isolated molecules excited either through the evanescent field at the quartz-liquid interface or as a thin layer of solution defined by micron-sized wires, giving diffraction-limited resolution of interconnected attoliter volume elements. The single-molecule diffusion coefficients were smaller and the unimolecular photodecomposition lifetimes were longer for the dye-DNA covalent complex as compared with those of the dye molecule itself. Unlike bulk studies, stochastic behavior was found for individual molecules of each type, and smaller diffusion coefficients were observed. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES LAB,US DOE,AMES,IA 50011. NR 27 TC 177 Z9 184 U1 2 U2 22 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD FEB 21 PY 1997 VL 275 IS 5303 BP 1106 EP 1109 DI 10.1126/science.275.5303.1106 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ503 UT WOS:A1997WJ50300038 PM 9027307 ER PT J AU Aldstadt, JH Olson, DC Martin, AF AF Aldstadt, JH Olson, DC Martin, AF TI Determination of volatile arsenicals in ambient air by flow injection SO ANALYTICA CHIMICA ACTA LA English DT Article DE flow injection; gas permeation; potentiometric stripping; arsenite; Lewisite ID POTENTIOMETRIC STRIPPING ANALYSIS; SULFUR-DIOXIDE; DERIVATIZATION; ACID AB We report the development of a method for determining trans-dichloro(2-chlorovinyl)arsine (Lewisite) in ambient air in near real time. Air monitoring of Lewisite is required to support arms control treaty inspections, weapons destruction processes, and remediation of hazardous waste sites. Flow injection (FI) techniques are used to integrate a gas permeation membrane (GPM) sampling unit to a detector based on the constant-current mode of potentiometric stripping analysis (PSA). The method indirectly measures Lewisite in ambient air by collecting vapor-phase Lewisite across a thin-walled rubber membrane and hydrolyzing it to form arsenite ion for detection by PSA. We tested silicone and natural rubber nonporous membranes with estimated wall thicknesses of 0.66 and 0.27 mm, respectively. The rubber GPM tubes are oriented linearly in the sampler, and the sample is collected at a flow rate of 200 ml/min through the cavity. We studied arsenic trichloride as a vapor-phase simulant for Lewisite, although we found its silicone rubber permeability characteristics unfavorable. Factors including membrane tube length, sampling time, and sampling temperature were examined during experiments in which vapor-phase Lewisite was generated at 0.99 ppb,. The typical response to Lewisite was fast (within one sampling cycle) and continuous readings to vapor-phase Lewisite measurements were stable (<20% relative standard deviation). On the basis of this testing, we estimate a working range for Lewisite from 0.5 to 50 mu g/m(3) using a 15 min total cycle time. C1 FIA SOLUT INC,GIG HARBOR,WA 98335. RP Aldstadt, JH (reprint author), ARGONNE NATL LAB,DIV ENVIRONM RES,9700 S CASS AVE ER-203,ARGONNE,IL 60439, USA. NR 33 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0003-2670 J9 ANAL CHIM ACTA JI Anal. Chim. Acta PD FEB 20 PY 1997 VL 338 IS 3 BP 215 EP 222 DI 10.1016/S0003-2670(96)00423-0 PG 8 WC Chemistry, Analytical SC Chemistry GA WK078 UT WOS:A1997WK07800006 ER PT J AU Miller, D QuinbyHunt, MS Hunt, AJ AF Miller, D QuinbyHunt, MS Hunt, AJ TI Laboratory studies of angle- and polarization-dependent light scattering in sea ice SO APPLIED OPTICS LA English DT Article DE scattering; sea ice; Mueller matrices; polarimetry; nephelometry ID OPTICAL-PROPERTIES; OCEAN; MATRICES AB The, angle- and polarization-dependent light scattering were measured for oriented first-year and multiyear sea ice taken from the Chukchi Sea near Pt. Barrow, Alaska. The entire Mueller matrix for these samples was determined at 532 nm. Mueller matrices were also determined for artificially grown saline ice samples and melted samples of the respective ice types. Phase functions for thin-slab samples are qualitatively consistent with calculations for scattering from brine inclusions in a solid ice medium and depend strongly on the shape of the scattering sample. Small orientation-dependent effects are observed for scattering from oriented sea ice. A simple model is used to describe qualitatively some features of the measured sea ice Mueller matrices. This model combines the effects of scattering for spherical inhomogeneities and the intrinsic birefringence of pure water ice. A set of Mueller matrix inequalities is presented and used to obtain physical insight into the measurement results. (C) 1997 Optical Society of America. RP Miller, D (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,CYCLOTRON RD,BERKELEY,CA 94720, USA. NR 28 TC 10 Z9 10 U1 0 U2 0 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD FEB 20 PY 1997 VL 36 IS 6 BP 1278 EP 1288 DI 10.1364/AO.36.001278 PG 11 WC Optics SC Optics GA WH289 UT WOS:A1997WH28900026 PM 18250801 ER PT J AU Cruddace, RG Kowalski, MP Fritz, GG Snyder, WA Fenimore, EE Ulmer, MP AF Cruddace, RG Kowalski, MP Fritz, GG Snyder, WA Fenimore, EE Ulmer, MP TI The baryon fraction in the perseus cluster: Results from Spartan 1 SO ASTROPHYSICAL JOURNAL LA English DT Article DE dark matter; galaxies, clusters, individual (Perseus); X-rays, galaxies ID X-RAY OBSERVATIONS; RICH CLUSTERS; DARK MATTER; GALAXIES; IRON; DYNAMICS; VELOCITY; EMISSION; RATIO; GAS AB Spatially and spectrally resolved X-ray observations of the Perseus cluster in the 1-10 keV band were made by the Spartan 1 instrument. Analysis of the data reveals that the dark matter comprises 60% of the total mass and is concentrated toward the cluster center. This concentration may be caused by a baryonic component of the dark matter, consisting of cluster gas which has cooled. The average luminous baryon fraction within the cluster is consistent with big bang nucleosynthesis only if the cosmic mass density lies in the range 0.12 < Omega < 0.26 (H-0 = 50 km s(-1) Mpc(-1)). The total mass derived from the X-ray data is 40% of that obtained from analysis of the galaxy spatial and velocity distributions. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. RP Cruddace, RG (reprint author), USN,RES LAB,EO HULBURT CTR SPACE RES,CODE 7620,4555 OVERLOOK AVE,WASHINGTON,DC 20375, USA. NR 29 TC 5 Z9 5 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1997 VL 476 IS 2 BP 479 EP 488 DI 10.1086/303634 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WH858 UT WOS:A1997WH85800005 ER PT J AU Cimatti, A Dey, A vanBreugel, W Hurt, T Antonucci, R AF Cimatti, A Dey, A vanBreugel, W Hurt, T Antonucci, R TI Keck spectropolarimetry of two high-z radio galaxies: Discerning the components of the alignment effect SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, active; galaxies, individual (3C 13, 3C 356); polarization; quasars, general; radio continuum, galaxies; scattering; ultraviolet, galaxies ID COOLING FLOWS; QUASARS; 3C-356; GAS; 3CR AB We present optical spectropolarimetric observations obtained with the W. M. Keck Telescope of two powerful, high-redshift radio galaxies which exhibit radio-optical alignments, 3C 13 (z = 1.351) and 3C 356 (z = 1.079). 3C 13 is fairly strongly polarized in the blue, with the electric vector oriented perpendicular to the major axis of UV continuum emission. 3C 356 is known to have two radio/optical components (labeled a and b) along the radio source axis, but it is unclear which of them is the nucleus of the radio source. Our observations show that both components a and b are polarized with the electric vectors in both cases oriented approximately orthogonal to the optical a-b axis. Component a also shows evidence for broad Mg II lambda 2800 emission both in polarized and total light, while the narrow forbidden lines are unpolarized Our observations support the unified model of powerful radio-loud active galactic nuclei (AGNs) and allow us for the first time to quantify the contribution of the different radiative components to the alignment effect of a high-z radio galaxy (3C 356a): the nonstellar radiation (scattered and nebular continua) constitutes about 80% of the total UV continuum emission at 2800 Angstrom and an evolved stellar population with an age similar to 1.5-2.0 Gyr can account for the remainder of the UV light. We also detect the stellar Ca II K absorption line in the spectra of both components. Although the present data do not clarify unambiguously whether a or b is the nucleus of 3C 356, they suggest that the scenario in which a contains the hidden quasar is energetically more favorable. If the nucleus is located in a, our observations show that electron scattering is plausible, and support the scenario in which 3C 356 is surrounded by an ionized intracluster medium, as suggested by ROSAT observations. C1 LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. NR 43 TC 49 Z9 49 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1997 VL 476 IS 2 BP 677 EP 684 DI 10.1086/303660 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WH858 UT WOS:A1997WH85800019 ER PT J AU Owens, A Denby, M Wells, A Keay, A Graessle, DE Blake, RL AF Owens, A Denby, M Wells, A Keay, A Graessle, DE Blake, RL TI The effect of X-ray absorption fine structure in soft X-ray astronomical telescopes SO ASTROPHYSICAL JOURNAL LA English DT Article DE instrumentation, detectors; space vehicles; telescopes; X-rays, general ID XANES AB Recent in-orbit measurements by high resolution soft X-ray telescopes have revealed low-level fine structure in target spectra that cannot be attributed to a celestial source. Ultimately, this can be traced to the ability of the new high spectral resolution silicon detectors to resolve X-ray absorption fine structure (XAFS) produced in the various detection subsystems. Based on measurements taken at the Daresbury Synchrotron Radiation Source (SRS) and the National Synchrotron Light Source (NSLS), we have modeled the full-up response function of the joint European X-ray Telescope (JET-X), taking into account edge structure generated in the detectors, filters, and mirrors. It is found that unfolding celestial source spectra using a response function in which the detailed edge shapes are calculated from standard absorption cross sections leads to the generation of spectral artifacts at every absorption edge. These in turn produce unacceptably high values of chi(2) in model fits for total source fluxes above similar to 4 x 10(4) counts. For JET-X, this corresponds to a source strength of similar to 0.4 millicrab observed for 10(5) s. Statistically significant ''linelike'' features are introduced into the derived source spectra with amplitudes as great as 10% of the source flux. For JET-X, these features rise above the 3 sigma level for integral source exposures above similar to 5 x 10(4) source counts. The largest. deviations in the residuals arise near 0.5 keV and 2.2 keV and are attributed to XAFS produced in the oxide surface layers of the CCD and the gold reflective surface of the mirrors, respectively. These results are significant for data interpretation tasks with the ASCA, JET-X, XMM, and Advanced X-Ray Astrophysics Facility (AXAF) telescopes. C1 SMITHSONIAN ASTROPHYS OBSERV,CAMBRIDGE,MA 02138. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Owens, A (reprint author), UNIV LEICESTER,DEPT PHYS & ASTRON,LEICESTER LE1 7RH,LEICS,ENGLAND. NR 26 TC 11 Z9 11 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1997 VL 476 IS 2 BP 924 EP 931 DI 10.1086/303628 PN 1 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WH858 UT WOS:A1997WH85800042 ER PT J AU Kim, AG Gabi, S Goldhaber, G Groom, DE Hook, IM Kim, MY Lee, JC Pennypacker, CR Perlmutter, S Small, IA Goobar, A Pain, R Ellis, RS McMahon, RG Boyle, BJ Bunclark, PS Carter, D Irwin, MJ Glazebrook, K Newberg, HJM Filippenko, AV Matheson, T Dopita, M Couch, WJ AF Kim, AG Gabi, S Goldhaber, G Groom, DE Hook, IM Kim, MY Lee, JC Pennypacker, CR Perlmutter, S Small, IA Goobar, A Pain, R Ellis, RS McMahon, RG Boyle, BJ Bunclark, PS Carter, D Irwin, MJ Glazebrook, K Newberg, HJM Filippenko, AV Matheson, T Dopita, M Couch, WJ TI Implications for the Hubble constant from the first seven supernovae at z>=0.35 SO ASTROPHYSICAL JOURNAL LA English DT Article DE distance scale; supernovae, general ID ABSOLUTE PEAK BRIGHTNESS; IA SUPERNOVAE; CEPHEID VARIABLES; DISCOVERY; DISTANCE; H(0) AB The Supernova Cosmology Project has discovered over 28 supernovae (SNs) at 0.35 < z < 0.65 in an ongoing program that uses Type Ia SNs (SN Ia's) as high-redshift distance indicators. Here we present measurements of the ratio between the locally observed and global Hubble constants H-0(L)/H-0(G), based on the first seven SNs of this high-redshift data set compared with 18 SNs at z less than or equal to 0.1 from the Cala/Tololo survey. If Omega(M) less than or equal to 1, then light-curve width corrected SN magnitudes yield H-0(L)/H-0(G) < 1.10 (95% confidence level) in both a Lambda = 0 and a flat universe. The analysis using the SN Ia's as standard candles without a light-curve width correction yields similar results. These results rule out the hypothesis that the discrepant ages of the Universe derived from globular clusters and recent measurements of the Hubble constant are attributable to a locally underdense bubble. Using the Cepheid-distance-calibrated absolute magnitudes for SN Ia's of Sandage et al., we can also measure the global Hubble constant, H-0(G). If Omega(M) greater than or equal to 0.2, we find that H-0(G) < 70 km s(-1) Mpc(-1) in a Lambda = 0 universe and H-0(G) < 78 km s(-1) Mpc(-1) in a flat universe, correcting the distant and local SN apparent magnitudes for light-curve width. Lower results for H-0(G) are obtained if the magnitudes are not width-corrected. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT ASTRON,BERKELEY,CA 94720. UNIV STOCKHOLM,STOCKHOLM,SWEDEN. UNIV PARIS,CNRS,IN2P3,F-75252 PARIS,FRANCE. INST ASTRON,CAMBRIDGE,ENGLAND. ROYAL GREENWICH OBSERV,CAMBRIDGE,ENGLAND. ANGLO AUSTRALIAN OBSERV,SYDNEY,NSW,AUSTRALIA. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. MT STROMLO & SIDING SPRING OBSERV,WODEN,ACT,AUSTRALIA. UNIV NEW S WALES,SYDNEY,NSW,AUSTRALIA. RP Kim, AG (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Perlmutter, Saul/I-3505-2015; Glazebrook, Karl/N-3488-2015; Dopita, Michael/P-5413-2014 OI Perlmutter, Saul/0000-0002-4436-4661; Glazebrook, Karl/0000-0002-3254-9044; Dopita, Michael/0000-0003-0922-4986 NR 33 TC 19 Z9 19 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5720 S WOODLAWN AVE, CHICAGO, IL 60637 SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1997 VL 476 IS 2 BP L63 EP L66 DI 10.1086/310507 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WH861 UT WOS:A1997WH86100003 ER PT J AU Mauche, CW AF Mauche, CW TI The extreme ultraviolet spectrum of the quasi-coherent oscillations of the dwarf nova SS Cygni SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars, individual (SS Cygni); stars, oscillations; ultraviolet, stars ID OUTBURST AB Data obtained by the Extreme Ultraviolet Explorer satellite are used to determine the EUV spectrum of the quasi-coherent oscillations of the dwarf nova SS Cygni. It is found that the spectrum of the oscillations is neither blue nor red nor gray relative to the net (oscillation-phase integrated) spectrum and hence that the oscillations cannot be explained by variations in the effective temperature, absorbing column density, or effective area, respectively. Instead, it is found that the amplitude of the oscillations is high at the relative maxima of the net spectrum and low to zero at the relative minima of the net spectrum. This behavior can be explained either by variations in the emission line flux atop a constant underlying continuum or by variations in the optical depth of a haze of overlapping absorption lines, in which case the optical depths must be tau less than or similar to 1 at the relative maxima of the net spectrum and tau much greater than 1 at the relative minima. RP Mauche, CW (reprint author), LAWRENCE LIVERMORE NATL LAB, L-41, POB 808, LIVERMORE, CA 94550 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD FEB 20 PY 1997 VL 476 IS 2 BP L85 EP L88 DI 10.1086/310500 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WH861 UT WOS:A1997WH86100008 ER PT J AU Ho, PM AF Ho, PM TI Riemannian geometry on quantum spaces SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article AB An algebraic formulation of Riemannian geometry on quantum spaces is presented, where Riemannian metric, distance, Laplacian, connection, and curvature have their counterparts. This description is also extended to complex manifolds. Examples include the quantum sphere, the complex quantum projective space and the two-sheeted space. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP Ho, PM (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. OI Ho, Pei-Ming/0000-0002-0466-0351 NR 9 TC 7 Z9 7 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD FEB 20 PY 1997 VL 12 IS 5 BP 923 EP 943 DI 10.1142/S0217751X97000694 PG 21 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA WE163 UT WOS:A1997WE16300006 ER PT J AU Blaudeau, JP Curtiss, LA AF Blaudeau, JP Curtiss, LA TI Optimized Gaussian basis sets for use with relativistic effective (core) potentials: K, Ca, Ga-Kr SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; SPIN-ORBIT OPERATORS; ELECTRONIC-STRUCTURE; DISSOCIATION-ENERGIES; ATOMS; EXTENSION; ELEMENTS; STATES; PSEUDOPOTENTIALS; CHEMISTRY AB Correlation-consistent valence basis sets were developed for the third-row main block elements (K, Ca, Ga-Kr) for use with relativistic effective core potentials. These basis sets are somewhat larger than double-zeta in size, with polarization functions, and are balanced for use in both Hartree-Fock and correlation calculations. Spin-orbit splittings for atoms and molecules are calculated and compared to experiment. These calculations use the approximate spin-orbit operator from the relativistic effective core potentials. The use of these results in the calculation of accurate thermochemical data is discussed. (C) 1997 John Wiley & Sons, Inc*. C1 ARGONNE NATL LAB, DIV MAT SCI, ARGONNE, IL 60439 USA. RP Blaudeau, JP (reprint author), ARGONNE NATL LAB, DIV CHEM TECHNOL, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 64 TC 27 Z9 27 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD FEB 20 PY 1997 VL 61 IS 6 BP 943 EP 952 DI 10.1002/(SICI)1097-461X(1997)61:6<943::AID-QUA7>3.0.CO;2-W PG 10 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA WG250 UT WOS:A1997WG25000007 ER PT J AU Kumer, JB Kawa, SR Roche, AE Mergenthaler, JL Smith, SE Taylor, FW Connell, PS Douglass, AR AF Kumer, JB Kawa, SR Roche, AE Mergenthaler, JL Smith, SE Taylor, FW Connell, PS Douglass, AR TI UARS first global N2O5 data sets: Application to a stratospheric warming event in January 1992 SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID SIMULTANEOUS INSITU MEASUREMENTS; DIODE-LASER SPECTROMETER; NORTHERN WINTER 1991/92; MESOSPHERIC SOUNDER; REACTIVE NITROGEN; NO2; MODEL; EVOLUTION; CLAES; O-3 AB For the first time, global measurements of N2O5 are available for study. N2O5 has long been a missing link in large-scale observations of stratospheric nitrogen species, the chemical family that comprises the major global loss cycle for ozone above about 25 km [McElroy et al., 1992]. N2O5 is also an important intermediate in conversion of NOx to HNO3, thus limiting the effect of nitrogen-catalyzed ozone destruction below about 25 km [Fahey et al., 1993]. The new N2O5 observations come from both the Cryogenic Limb Array Etalon Spectrometer (CLAES) and Improved Stratospheric and Mesospheric Sounder (ISAMS) instruments on the Upper Atmosphere Research Satellite (UARS), providing near-global coverage at high spatial and temporal resolution for almost 20 months. Here we focus on data obtained near 40 km during a stratospheric warming in January 1992. The N2O5 fields show globally coherent structures with large variation in response to global transport coupled with highly temperature dependent chemistry. Comparison of the data with chemistry and transport models indicates that our understanding of processes controlling N2O5 amounts and the interaction with other reactive nitrogen Species is largely accurate under most conditions; however, an exceptional disagreement is found in the prolonged polar dark. This example demonstrates the utility of global data to understand the combined effects of chemistry and transport on N2O5 under a wide range of conditions. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. UNIV OXFORD, DEPT PHYS, OXFORD OX1 2JD, ENGLAND. RP Kumer, JB (reprint author), LOCKHEED PALO ALTO RES LABS, 3251 HANOVER ST, PALO ALTO, CA 94304 USA. RI Douglass, Anne/D-4655-2012; Kawa, Stephan/E-9040-2012 NR 50 TC 15 Z9 15 U1 0 U2 0 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 FEB 20 PY 1997 VL 102 IS D3 BP 3575 EP 3582 DI 10.1029/96JD03055 PG 8 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WK266 UT WOS:A1997WK26600005 ER PT J AU Zhao, X Turco, RP Kao, CYJ Elliott, S AF Zhao, X Turco, RP Kao, CYJ Elliott, S TI Aerosol-induced chemical perturbations of stratospheric ozone: Three-dimensional simulations and analysis of mechanisms SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID GENERAL-CIRCULATION MODEL; SULFURIC-ACID-SOLUTIONS; MOUNT-PINATUBO; MT-PINATUBO; HETEROGENEOUS CHEMISTRY; SULFATE AEROSOLS; TROPICAL OZONE; ATMOSPHERIC BROMINE; INSITU MEASUREMENTS; VOLCANIC AEROSOLS AB An atmospheric general circulation model is coupled with a stratospheric photochemical model to simulate the chemical/dynamical perturbations associated with background and volcanically perturbed aerosols in the lower stratosphere. The present work focuses on short-term anomalies at middle and high latitudes in the northern hemisphere, where large ozone depletions have been observed in late winter and early spring, particularly following the eruption of Mount Pinatubo. Five fully coupled simulations are analyzed, corresponding to a control case with only gas phase chemistry, and cases including heterogeneous chemistry on background aerosols, on El Chichon-type, and on Pinatubo-type aerosols. It is found that heterogeneous reactions occurring on sulfate aerosols (background or postvolcanic) can strongly perturb the chemical partitioning in the lower stratosphere, leading to significant ozone depletion through enhanced chlorine, bromine, and odd-hydrogen catalytic cycles. In the Arctic lower stratosphere, the maximum zonal and March monthly mean local ozone reductions (with respect to the control case) can exceed 15% for the background aerosol case, 40% for the El Chichon case, and 50% for the Pinatubo case. The corresponding zonal mean total column ozone decreases are roughly 5% and 15% for the background and volcanic aerosol cases, respectively. In the most extreme case tested (post-Pinatubo), a large ozone depletion below 30 mbar is offset to some extent by an ozone increase above that level. The results of a sensitivity study (in which the aerosols are distributed closer to the tropics, as might occur early after an eruption at low latitude) lead tp relatively small total ozone depletions at northern high latitudes, and small ozone increases in the tropical lower stratosphere. The reduced impact on total ozone at high latitudes is associated both with local ozone increases above 30 mbar and with poleward transport of enhanced ozone from the tropical lower stratosphere. The ozone increase at low latitudes is the net result of compensating changes in the catalytic destruction cycles involving odd-nitrogen and chlorine species activated by heterogeneous processes at the low temperatures and abundant sunlight found near the tropical tropopause. Our:simulations indicate that ozone variations triggered by volcanic injections of aerosols depend on the global distribution as well as th abundance of the particles and-their evolution over time, and on the initial dynamical-radiative-chemical state of the atmosphere, which itself exhibits large seasonal and interannual variability. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Zhao, X (reprint author), UNIV CALIF LOS ANGELES, DEPT ATMOSPHER SCI, 405 HILGARD AVE, LOS ANGELES, CA 90095 USA. NR 99 TC 16 Z9 17 U1 1 U2 5 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 FEB 20 PY 1997 VL 102 IS D3 BP 3617 EP 3637 DI 10.1029/96JD03406 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WK266 UT WOS:A1997WK26600009 ER PT J AU Chuang, CC Penner, JE Taylor, KE Grossman, AS Walton, JJ AF Chuang, CC Penner, JE Taylor, KE Grossman, AS Walton, JJ TI An assessment of the radiative effects of anthropogenic sulfate SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID AEROSOL SIZE DISTRIBUTIONS; MARINE BOUNDARY-LAYER; GREENHOUSE GASES; UNITED-STATES; CLOUD ALBEDO; OPTICAL-PROPERTIES; ATLANTIC-OCEAN; SULFUR CYCLE; PACIFIC; MODEL AB We use a coupled climate/chemistry model with cloud nucleation processes parameterized in terms of local aerosol number, anthropogenic sulfate mass concentration, and updraft velocity to investigate both direct and indirect anthropogenic sulfate radiative forcings. We estimate that the global direct radiative forcing is about -0.4 W m(-2) with a maximum over Europe where the strongest anthropogenic sulfur emissions occur. With different approaches for the formation of anthropogenic sulfate and its relation to aerosol size distribution, we estimate that the indirect forcing may range from -0.6 to -1.6 W m(-2). This range reduces to -0.4 to -1.1 W m(-2) if a prescribed marine background particle number concentration is universally applied over the ocean. Contrary to the direct effect which is mote significant over continents, the calculated maximum of indirect forcing is located over the Atlantic Ocean near the coastline of North America. Our simulations indicate that anthropogenic sulfate may result in important increases in reflected Solar radiation, which would mask locally the warming from increased greenhouse gases. We also compare the simulated cloud drop effective radii with those retrieved from satellite data to validate the accuracy of our cloud drop parameterization. RP Chuang, CC (reprint author), LAWRENCE LIVERMORE NATL LAB, DIV ATMOSPHER SCI L103, LIVERMORE, CA 94551 USA. RI Taylor, Karl/F-7290-2011; chuang, cathy/H-4814-2012; Penner, Joyce/J-1719-2012 OI Taylor, Karl/0000-0002-6491-2135; NR 77 TC 168 Z9 183 U1 2 U2 12 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 FEB 20 PY 1997 VL 102 IS D3 BP 3761 EP 3778 DI 10.1029/96JD03087 PG 18 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WK266 UT WOS:A1997WK26600018 ER PT J AU Mazurek, M Masonjones, MC Masonjones, HD Salmon, LG Cass, GR Hallock, KA Leach, M AF Mazurek, M Masonjones, MC Masonjones, HD Salmon, LG Cass, GR Hallock, KA Leach, M TI Visibility-reducing organic aerosols in the vicinity of grand canyon national park: Properties observed by high resolution gas chromatography SO JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES LA English DT Article ID WESTERN UNITED-STATES; CALIFORNIA AIR-QUALITY; LOS-ANGELES; MASS-SPECTROMETRY; ATMOSPHERIC OXIDATION; CARBONACEOUS AEROSOL; SOURCE APPORTIONMENT; SECONDARY AEROSOL; SEASONAL TRENDS; REGIONAL HAZE AB Fine particle and total airborne particle samples were collected during August 1989 within the Grand Canyon (Indian Gardens (IG)) and on its south rim (Hopi Point (HP)) to define summertime organic aerosol concentration and composition as a function of elevation at Grand Canyon National Park. Inorganic chemical constituents were analyzed also to help place the relative importance of organics in perspective. Fine particle organic aerosols were approximately equal in concentration to sulfate aerosols at both sites. Monthly average mass concentrations for fine aerosol organics ranged from 1.1 mu g m(-3) (IG) to 1.3 mu g m(-3) (HP), while the organic aerosol concentration within total suspended particulate matter samples ranged from 1.9 mu g m(-3) (IG) to 2.1 mu g m(-3) (HP). Aerosol organics that could be evaluated by gas chromatography with flame ionization detection (GC-FID) (elutable organics) constituted 27% to 53% of the total organics mass collected as fine or total aerosol. At each site, roughly half of the elutable organics fine aerosol fraction was composed of highly polar organic compounds. Distributions of the elutable organics were compared to Los Angeles fine aerosol samples and to distributions of authentic sources of aerosol organics. It was found that the Grand Canyon organic aerosol during August 1989 did not resemble diluted aged Los Angeles organic aerosol, indicating that most of the organic particulate matter at the Grand Canyon at the time studied originated from other sources. C1 BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. CALTECH, PASADENA, CA 91125 USA. RI Xiongfei, Zhao/G-7690-2015 NR 87 TC 49 Z9 50 U1 0 U2 11 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 FEB 20 PY 1997 VL 102 IS D3 BP 3779 EP 3793 DI 10.1029/96JD02719 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WK266 UT WOS:A1997WK26600019 ER PT J AU List, FA Kroeger, DM Selvamanickam, V AF List, FA Kroeger, DM Selvamanickam, V TI Hysteresis of the transport critical current of (Tl,Pb)-(Sr,Ba)-Ca-Cu-O and Bi-Sr-Ca-Cu-O conductors: Effects of temperature and magnetic field SO PHYSICA C LA English DT Article DE critical current density; granular superconductivity; grain boundaries; penetration depth ID CRITICAL-CURRENT-DENSITY; HIGH-TC SUPERCONDUCTORS; THIN-FILMS; IRREVERSIBILITY; MICROSTRUCTURE; MODEL; YBCO; BULK AB The transport critical current (I-c) of polycrystalline (Tl0.5Pb0.5)(Sr0.8Ba0.2)(2)Ca2Cu3Ox (Tl1223) and Bi2Sr2CaCu2Ox (Bi2212) conductors has been determined for a range of temperature (25-77.3 K) and a range of externally applied magnetic field (H-app = 0-1.5 T). Hysteresis of the I-c versus H-app behavior has been observed for the Tl1223 conductor and has been interpreted using Bean's critical state model [1]. For the Tl1223 conductor, the remnant critical current measured for H-app = 0 after exposure to 1.5 T was found to be independent of temperature. This behavior has been shown to be consistent with the critical state model. No hysteresis of I-c versus H-app was detectable for the Bi2212 conductor. C1 INTERMAGNET GEN CORP,LATHAM,NY 12110. RP List, FA (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 23 TC 7 Z9 7 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD FEB 20 PY 1997 VL 275 IS 3-4 BP 220 EP 230 DI 10.1016/S0921-4534(96)00714-9 PG 11 WC Physics, Applied SC Physics GA WM056 UT WOS:A1997WM05600006 ER PT J AU Paranthaman, M Goyal, A List, FA Specht, ED Lee, DF Martin, PM He, Q Christen, DK Norton, DP Budai, JD Kroeger, DM AF Paranthaman, M Goyal, A List, FA Specht, ED Lee, DF Martin, PM He, Q Christen, DK Norton, DP Budai, JD Kroeger, DM TI Growth of biaxially textured buffer layers on rolled-Ni substrates by electron beam evaporation SO PHYSICA C LA English DT Article DE buffer layers; biaxial texture; rolled-Ni substrates; E-beam evaporation ID YBA2CU3O7-DELTA THICK-FILMS; LASER DEPOSITION; BICRYSTALS AB This paper describes the development of two buffer layer architectures on rolled-Ni substrates using an electron beam evaporation technique. The first buffer layer architecture consists of an epitaxial laminate of CeO2/Pd/Ni. The second alternative buffer layer consists of an epitaxial laminate of YSZ/CeO2/Ni. The cube (100) texture in the Ni was produced by cold-rolling followed by recrystallization. The CeO2 films were grown epitaxially on both Pd-buffered and textured-Ni substrates. The YSZ films were grown epitaxially on CeO2-buffered Ni substrates. The crystallographic orientation of the Pd, CeO2, and YSZ films were all (100). We also studied the effect of the CeO2 layer thickness and crack formation on textured-Ni substrates. The layer thickness was found to be critical. For some thicknesses, cracks formed in the CeO2 layer. The presence of YSZ layers on the CeO2 layers seem to alleviate the cracks that are formed underneath. Our SEM studies showed that both CeO2 (3-10 nm thick underlayer) and YSZ layers were smooth and continuous. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RP Paranthaman, M (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. RI Christen, David/A-9709-2008; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306 NR 16 TC 150 Z9 154 U1 2 U2 18 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 20 PY 1997 VL 275 IS 3-4 BP 266 EP 272 DI 10.1016/S0921-4534(96)00713-7 PG 7 WC Physics, Applied SC Physics GA WM056 UT WOS:A1997WM05600011 ER PT J AU Antoniadis, I Mazur, PO Mottola, E AF Antoniadis, I Mazur, PO Mottola, E TI Criticality and scaling in 4D quantum gravity SO PHYSICS LETTERS B LA English DT Article ID CONFORMAL SECTOR; TRIANGULATION; GEOMETRIES AB We present a simple argument which determines the critical value of the anomaly coefficient in four dimensional conformal factor quantum gravity, at which a phase transition between a smooth and elongated phase should occur. The argument is based on the contribution of singular configurations (''spikes'') which dominate the partition function in the infrared, The critical value is the analog of c = 1 in the theory of random surfaces, and the phase transition is similar to the Berezenskii-Kosterlitz-Thouless transition. The critical value we obtain is in agreement with the previous canonical analysis of physical states of the conformal factor and may explain why a smooth phase of quantum gravity has not yet been observed in simplicial simulations. We also rederive the scaling relations in the smooth phase in light of this determination of the critical coupling. C1 UNIV S CAROLINA,DEPT PHYS & ASTRON,COLUMBIA,SC 29208. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. RP Antoniadis, I (reprint author), ECOLE POLYTECH,CTR PHYS THEOR,CNRS,UPR A0014,F-91128 PALAISEAU,FRANCE. OI Mazur, Pawel/0000-0002-1679-3637 NR 25 TC 38 Z9 38 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 FEB 20 PY 1997 VL 394 IS 1-2 BP 49 EP 56 DI 10.1016/S0370-2693(96)01663-2 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK793 UT WOS:A1997WK79300009 ER PT J AU Bern, Z Dixon, L Dunbar, DC Kosower, DA AF Bern, Z Dixon, L Dunbar, DC Kosower, DA TI One-loop self-dual and N=4 super Yang-Mills SO PHYSICS LETTERS B LA English DT Article ID GAUGE-THEORY AMPLITUDES; STRING-BASED METHODS; CHERN-SIMONS THEORY; HELICITY AMPLITUDES; DIMENSIONAL REGULARIZATION; HIGH-ENERGIES; MULTIPLE BREMSSTRAHLUNG; MULTIPHOTON PRODUCTION; GRAVITON SCATTERING; COLLINEAR LIMITS AB We conjecture a simple relationship between the one-loop maximally helicity violating gluon amplitudes of ordinary QCD (all helicities identical) and those of N = 4 supersymmetric Yang-Mills (all but two helicities identical). Because the amplitudes in self-dual Yang Mills have been shown to be the same as the maximally helicity violating ones in QCD, this conjecture implies that they are also related to the maximally helicity violating ones of N = 4 supersymmetric Yang-Mills. We have an explicit proof of the relation up to the six-point amplitude; for amplitudes with more external legs, it remains a conjecture. A similar conjecture relates amplitudes in self-dual gravity to maximally helicity violating N = 8 supergravity amplitudes. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. UNIV COLL SWANSEA,DEPT PHYS,SWANSEA SA2 8PP,W GLAM,WALES. CTR ETUD SACLAY,SERV PHYS THEOR,F-91191 GIF SUR YVETTE,FRANCE. RP Bern, Z (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS,405 HILGARD AVE,LOS ANGELES,CA 90095, USA. OI dunbar, david/0000-0003-2433-1675 NR 79 TC 164 Z9 165 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 FEB 20 PY 1997 VL 394 IS 1-2 BP 105 EP 115 DI 10.1016/S0370-2693(96)01676-0 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK793 UT WOS:A1997WK79300018 ER PT J AU Samuel, MA Abraha, T Yu, JH AF Samuel, MA Abraha, T Yu, JH TI The strong coupling constant, alpha(s), from W+jet processes: An analysis using Pade approximants SO PHYSICS LETTERS B LA English DT Article ID ESTIMATING PERTURBATIVE COEFFICIENTS; QUANTUM-FIELD THEORY; STATISTICAL PHYSICS; QCD AB The recent results for R = sigma(W+1jet)/sigma(W+0jets) obtained by the DO Collaboration at Fermilab are reanalyzed. We use Pade Approximants (PA) to estimate the higher-order QCD corrections, which we find are on the order of 4%. We observed that using PA, we obtain the predictions of R increased by approximately 4%, independent of parton distribution functions used in the prediction, and are consistently lower by about one standard deviation compared to the experimental result. Inaddition, they are independent of the values of alpha(M(z)) used in the parton distribution function fits. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Samuel, MA (reprint author), OKLAHOMA STATE UNIV,DEPT PHYS,STILLWATER,OK 74078, USA. NR 18 TC 5 Z9 5 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 FEB 20 PY 1997 VL 394 IS 1-2 BP 165 EP 169 DI 10.1016/S0370-2693(96)01673-5 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK793 UT WOS:A1997WK79300027 ER PT J AU Zheng, YJ Ornstein, RL AF Zheng, YJ Ornstein, RL TI Role of active site tyrosine in glutathione S-transferase: Insights from a theoretical study on model systems SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID NUCLEAR MAGNETIC-RESONANCE; ENZYME-CATALYZED REACTIONS; BARRIER HYDROGEN-BONDS; 3-DIMENSIONAL STRUCTURE; CRYSTAL-STRUCTURE; CARBON ACIDS; PROTON ABSTRACTION; AMINO-ACIDS; N-TERMINUS; RESOLUTION AB Ab initio molecular orbital theory was used to examine the role of active site tyrosine in glutathione S-transferases by using appropriate model systems. The location of the key mechanistic proton of the enzyme-glutathione binary complex, O- - -H- - -S, was predicted to be near the phenolic oxygen, which is in agreement with experiments. However, the position of the proton can be manipulated by changing the acidity of the tyrosine, which can be accomplished by either introducing a substituent group to the tyrosine phenol ring or changing the protein environment. Thus, our study seems to have resolved previous confusion as to where the proton is located. The hydrogen bonding between tyrosine and thiolate of glutathione is very strong. On the basis of our present study, we propose that, in the Y6F (Tyr --> Phe) mutant, a water molecule replaces the function of the hydroxyl group of the active site tyrosine of the wild-type enzyme. Several lines of evidence in support of the above hypothesis are discussed. The latter hypothesis is reminiscent of the notion of substrate-assisted catalysis. C1 PACIFIC NW LAB, ENVIRON MOL SCI LAB, RICHLAND, WA 99352 USA. NR 55 TC 23 Z9 23 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD FEB 19 PY 1997 VL 119 IS 7 BP 1523 EP 1528 DI 10.1021/ja961667h PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA WJ097 UT WOS:A1997WJ09700004 ER PT J AU Stephenson, JL McLuckey, SA AF Stephenson, JL McLuckey, SA TI Gaseous protein cations are amphoteric SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID TANDEM MASS-SPECTROMETRY; CHARGED OLIGONUCLEOTIDE ANIONS; COLLISION-INDUCED DISSOCIATION; ASSISTED LASER-DESORPTION; PROTON-TRANSFER REACTIONS; ION-MOLECULE REACTIONS; CYTOCHROME-C IONS; ELECTROSPRAY-IONIZATION; GAS-PHASE; DIELECTRIC POLARIZABILITY AB Singly- and multiply-protonated ubiquitin molecules are found to react with iodide anions, and certain other anions, by attachment of the anion, in competition with proton transfer to the anion. The resulting adduct ions are relatively weakly bound and dissociate upon collisional activation by loss of the neutral acid derived from the anion. Adduct ions that behave similarly can also be formed via ion/molecule reactions involving the neutral acid. The ion/molecule reaction phenomenology, however, stands in contrast with that expected based on the reaction site(s) being charged. Reaction rates increase inversely with charge state and the total number of neutral molecules that add to the protein cations increases inversely with cation charge. These observations are inconsistent with the formation of proton-bound clusters but are fully consistent with the formation of ion pairs or dipole/dipole bonding involving the neutral acid and neutral basic sites in the protein. The ion/ion reactions can be interpreted on the basis of conjugate acid/base chemistry in which the anion, which is a strong gaseous base, reacts with a protonated site, which is a strong gaseous acid. Adduct ions can also be formed via ion/molecule reaction which, on the basis of microscopic reversibility, implies that the neutral acid interacts with neutral basic sites on the protein cation. These results suggest that acid adduction to gaseous protein cations can be complementary in nature to chemical reactions, such as proton transfer and hydrogen/deuterium exchange, that are strongly mediated by the charge site(s). C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 96 TC 56 Z9 56 U1 2 U2 7 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 FEB 19 PY 1997 VL 119 IS 7 BP 1688 EP 1696 DI 10.1021/ja9632973 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA WJ097 UT WOS:A1997WJ09700023 ER PT J AU Lamp, BD Hobara, D Porter, MD Niki, K Cotton, TM AF Lamp, BD Hobara, D Porter, MD Niki, K Cotton, TM TI Correlation of the structural decomposition and performance of pyridinethiolate surface modifiers at gold electrodes for the facilitation of cytochrome c heterogeneous electron-transfer reactions SO LANGMUIR LA English DT Article ID ORGANIZED MOLECULAR ASSEMBLIES; ENHANCED RAMAN-SPECTROSCOPY; REDOX REACTION-MECHANISM; ENERGY LOSS SPECTROSCOPY; MONOLAYER FILMS; ALKANETHIOLATE MONOLAYERS; ORGANOSULFUR COMPOUNDS; ELECTROCHEMISTRY; 4,4'-BIPYRIDYL; VOLTAMMETRY AB This paper describes the results of an electrochemical and spectroscopic (infrared reflection and X-ray photoelectron spectroscopies) investigation of the modified gold electrode surfaces prepared from dilute ethanolic solutions of 4-mercaptopyridine (PySH) and 4,4'-dipyridyl disulfide (PySS). Both precursors have been used extensively as facilitators for the electron transfer of redox proteins like cytochrome c (cyt c). During the course of an investigation of the interfacial architectures formed from the two different precursors, a previously unreported structural instability in the adlayers was discovered. This instability manifests itself as a decrease in the ability of the modified surfaces to facilitate the electron transfer of cyt c that correlates with an increase of the immersion time in the precursor solutions. Results are presented that delineate the decrease in facilitator performance and probe the structural changes resulting in the decrease in performance. Together, the electrochemical and surface spectroscopic findings reveal that the modified surfaces spontaneously decompose to yield an adlayer composed largely of adsorbed atomic and oligomeric sulfur, an adlayer that we found to be ineffective in the facilitation of the electron transfer reaction of cyt c. The implications of these findings on the use of this type of modifier to studies of electron transfer reactions of redox proteins and to issues of the general structural stability of organosulfur-based monolayers are briefly discussed. C1 US DOE,AMES LAB,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,MICROANALYT INSTRUMENTAT CTR,AMES,IA 50011. YOKOHAMA NATL UNIV,DEPT CHEM PHYS,YOKOHAMA,KANAGAWA 240,JAPAN. NR 57 TC 84 Z9 84 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD FEB 19 PY 1997 VL 13 IS 4 BP 736 EP 741 DI 10.1021/la960637p PG 6 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WJ569 UT WOS:A1997WJ56900022 ER PT J AU Walker, D Nelson, WS Buhlmann, KA Avise, JC AF Walker, D Nelson, WS Buhlmann, KA Avise, JC TI Mitochondrial DNA phylogeography and subspecies issues in the monotypic freshwater turtle Sternotherus odoratus SO COPEIA LA English DT Article ID RESTRICTION ENDONUCLEASES; POPULATIONS AB Phylogeographic variation in mitochondrial (mt) DNA restriction sites is described for populations of the monotypic stinkpot turtle (Sternotherus odoratus) from the southeastern United States. Stinkpots display pronounced and hierarchical mtDNA phylogeographic differentiation, ranging from genetically shallow differences among local populations to genetically deep distinctions among regional assemblages of haplotypes. Both magnitude and general pattern of intraspecific mtDNA phylogeography in S. odoratus are remarkably similar to those in a related species (Sternotherus minor) that traditionally has been considered ditypic based on morphological and genetic appraisals. The pronounced phylogeographic population structure in S. odoratus effectively falsifies prior hypotheses that extensive dispersal and gene flow account for the morphometric conservatism among geographic populations. These findings also raise broader issues concerning the significance of subspecies designations in testudine systematics. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, AIKEN, SC 29801 USA. RP Walker, D (reprint author), UNIV GEORGIA, DEPT GENET, ATHENS, GA 30602 USA. NR 23 TC 23 Z9 23 U1 1 U2 6 PU AMER SOC ICHTHYOLOGISTS & HERPETOLOGISTS PI MIAMI PA MAUREEN DONNELLY, SECRETARY FLORIDA INT UNIV BIOLOGICAL SCIENCES, 11200 SW 8TH STREET, MIAMI, FL 33199 USA SN 0045-8511 EI 1938-5110 J9 COPEIA JI Copeia PD FEB 18 PY 1997 IS 1 BP 16 EP 21 DI 10.2307/1447835 PG 6 WC Zoology SC Zoology GA WK260 UT WOS:A1997WK26000003 ER PT J AU Lee, JR Burke, VJ Gibbons, JW AF Lee, JR Burke, VJ Gibbons, JW TI Behavior of hatchling Alligator mississippiensis exposed to ice SO COPEIA LA English DT Article ID WEATHER RP Lee, JR (reprint author), SAVANNAH RIVER ECOL LAB,DRAWER E,AIKEN,SC 29802, USA. NR 7 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC ICHTHYOLOGISTS HERPETOLOGISTS BUSINESS OFFICE PI CARBONDALE PA SOUTHERN ILLINOIS UNIV, DEPT ZOOLOGY, CARBONDALE, IL 62901-6501 SN 0045-8511 J9 COPEIA JI Copeia PD FEB 18 PY 1997 IS 1 BP 224 EP 226 DI 10.2307/1447864 PG 3 WC Zoology SC Zoology GA WK260 UT WOS:A1997WK26000032 ER PT J AU Albinati, A Eckert, J Pregosin, P Ruegger, H Salzmann, R Stossel, C AF Albinati, A Eckert, J Pregosin, P Ruegger, H Salzmann, R Stossel, C TI NMR studies of chiral P,S-chelate platinum, rhodium, and iridium complexes and the X-ray structure of a palladium(II) allyl derivative SO ORGANOMETALLICS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; ASYMMETRIC CATALYTIC ALLYLATION; METAL-COMPLEXES; FERROCENYL LIGANDS; CRYSTAL-STRUCTURES; ALKYLATION; CHEMISTRY; MECHANISM; PD; HYDROBORATION AB Several Rh(I), Ir(III), and Pt(II) complexes of the chiral P,S-bidentate ligand 2 have been prepared and characterized. Detailed two-dimensional NMR studies show that (i) the boat-type chelate ring and the stereogenic sulfur center can invert rapidly at ambient temperature and (ii) the sulfur donor may dissociate, essentially destroying the chiral pocket. The solid-state structure of [Pt(eta(3)-C3H5)(2)]PF6 (3) has been determined and the sulfur substituent shown to have an axial orientation. The six-membered chelate ring takes up a boatlike conformation. As shown by an X-ray diffraction study for 3, and via incoherent inelastic neutron scattering (IINS) measurements for the Pd analog, 4, the OH group is remote from the metal atom. C1 ETH ZURICH, INORGAN CHEM LAB, CH-8092 ZURICH, SWITZERLAND. UNIV MILAN, INST PHARMACEUT CHEM, I-20131 MILAN, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. RI Albinati, Alberto/I-1262-2015 OI Albinati, Alberto/0000-0002-8779-3327 NR 70 TC 64 Z9 64 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0276-7333 EI 1520-6041 J9 ORGANOMETALLICS JI Organometallics PD FEB 18 PY 1997 VL 16 IS 4 BP 579 EP 590 DI 10.1021/om960823q PG 12 WC Chemistry, Inorganic & Nuclear; Chemistry, Organic SC Chemistry GA WJ337 UT WOS:A1997WJ33700018 ER PT J AU Puck, TT Johnson, R Rasumussen, S AF Puck, TT Johnson, R Rasumussen, S TI A system for mutation measurement in mammalian cells: Application to gamma-irradiation SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID INDUCED CHROMOSOMAL-ABERRATIONS; HUMAN-LYMPHOCYTES; X-RAY; CHROMATID ABERRATIONS; CULTURED HUMAN; DNA-REPAIR; CAFFEINE; G2; RADIATION; MUTAGENESIS AB Monitoring of mutagenesis by environmental agents for the purpose of preventing genetic disease including cancer must include quantitation of cell killing, sensitive measurement of mutation production by appropriate doses of each agent, and assessment of mutation repair effects in mammalian cells. A four-step procedure, in the presence and absence of a repair suppressor, is proposed: (i) determination of the survival curve; (ii) measurement of the mitotic index in cells collected after treatment with colcemid; (iii) construction of a mutagenesis yield curve in the presence and absence of a repair suppressor, like caffeine; and (iv) assessment of the effect of test agents on the repair of mutations produced by other mutagens. The procedure is quantitative, reproducible, and reasonably rapid. It involves measurement of mutations causing visible chromosomal aberrations, Numerical parameters are proposed defining quantitatively mutation, cell killing, and mutation repair capacity. The procedure is applied to gamma-irradiation and can detect the effects of doses as low as 2-5 cGy. Theoretical analysis of the underlying processes is presented, using the concept of D-E(0), the effective dose of mutagen after repair mechanisms and neutralizing agents have acted. Microscopically visible chromosome aberrations are due to mutations that distort the process of mitotic chromosome condensation, with or without actual chromosome breakage. C1 UNIV COLORADO,SCH MED,DEPT MED,DENVER,CO 80262. LOS ALAMOS NATL LAB,DIV THEORET,CTR NONLINEAR STUDIES,DIV OFF,LOS ALAMOS,NM 87501. SANTA FE INST,SANTA FE,NM 87501. RP Puck, TT (reprint author), ELEANOR ROOSEVELT INST CANC RES,1899 GAYLORD ST,DENVER,CO 80206, USA. NR 36 TC 13 Z9 14 U1 0 U2 0 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 FEB 18 PY 1997 VL 94 IS 4 BP 1218 EP 1223 DI 10.1073/pnas.94.4.1218 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ621 UT WOS:A1997WJ62100031 PM 9037033 ER PT J AU Rowning, BA Wells, J Wu, M Gerhart, JC Moon, RT Larabell, CA AF Rowning, BA Wells, J Wu, M Gerhart, JC Moon, RT Larabell, CA TI Microtubule-mediated transport of organelles and localization of beta-catenin to the future dorsal side of Xenopus eggs SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TUMOR-SUPPRESSOR PROTEIN; CORTICAL ROTATION; FROG EGGS; AXIS; EMBRYOS; OVEREXPRESSION; DISPLACEMENT; IRRADIATION; ASSOCIATION; CYTOPLASM AB The dorsal-ventral axis in frog embryos is specified during the first cell cycle, when the cortex rotates relative to the cytoplasmic core along parallel microtubules associated with the core. Cytoplasmic transfer experiments suggest that dorsal determinants are transported 90 degrees from the vegetal pole to the dorsal equator, even though the cortex rotates only 30 degrees. Here we show that, during rotation, small endogenous organelles are rapidly propelled along the subcortical microtubules toward the future dorsal side and that fluorescent carboxylated beads injected into the vegetal pole are transported at least 60 degrees toward the equator. We also show that deuterium oxide, which broadens the zone of dorsalization even though it reduces the extent of rotation and is known to randomize the microtubules, also randomizes the direction of organelle transport. Moreover, beta-catenin, a component of the Wnt signaling pathway that possesses dorsalizing activity in Xenopus, colocalizes with subcortical microtubules at the dorsal side of the egg at the end of rotation. We propose that cortical rotation functions to align subcortical microtubules, which then mediate the transport of dorsal determinants toward their plus ends on one side of the egg. C1 UNIV WASHINGTON, SCH MED, HOWARD HUGHES MED INST, SEATTLE, WA 98195 USA. UNIV WASHINGTON, SCH MED, DEPT PHARMACOL, SEATTLE, WA 98195 USA. UNIV CALIF BERKELEY, DEPT MOL & CELL BIOL, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Moon, Randall/B-1743-2014 OI Moon, Randall/0000-0002-9352-1408 FU NIGMS NIH HHS [R01 GM19363] NR 31 TC 120 Z9 123 U1 0 U2 5 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 FEB 18 PY 1997 VL 94 IS 4 BP 1224 EP 1229 DI 10.1073/pnas.94.4.1224 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ621 UT WOS:A1997WJ62100032 PM 9037034 ER PT J AU Torigoe, C Goldstein, B Wofsy, C Metzger, H AF Torigoe, C Goldstein, B Wofsy, C Metzger, H TI Shuttling of initiating kinase between discrete aggregates of the high affinity receptor for IgE regulates the cellular response SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID BASOPHILIC LEUKEMIA-CELLS; IMMUNOGLOBULIN-E; TYROSINE KINASES; FC-EPSILON; PHOSPHORYLATION; DESENSITIZATION; ACTIVATION; ENGAGEMENT; SIGNAL; BIND AB Using defined oligomers of IgE, our group previously studied the quantitative relationship between the aggregation of the high affinity receptors for IgE (Fc epsilon RI) and the earliest signals initiated by such aggregation: the phosphorylation of tyrosines on the receptor, Notably, at certain doses of the oligomers such phosphorylation reached a plateau level well before the aggregation of the receptors had reached a maximum, These findings and others led us to propose that aggregates of the receptor were competing for a limited amount of the critical kinase-thought to be Lyn in this system, This paper describes a test of this proposal, We incubated cells with two distinguishable IgEs and examined the effect of aggregating one or the other or both types on the phosphorylation, When receptors binding antigen-specific IgE were aggregated with polyvalent antigen, they became rapidly phosphorylated as expected, Remarkably, however, Fc epsilon RI that had already been phosphorylated by the binding of dimers of IgE, became dephosphorylated simultaneously, Furthermore, when the antigen-driven aggregates were dissociated with hapten, the phosphorylation pattern reverted to that seen prior to the addition of antigen: as the antigen-driven aggregates became dephosphorylated, the receptors stably aggregated by the bound oligomers became rapidly rephosphorylated, Dephosphorylation of oligomer-driven aggregates was also partially reversed during the ''spontaneous'' dephosphorylation of the antigen-driven receptors seen at longer times after addition of antigen. Thus signal transduction in this system is in part regulated by the shuttling of limited amounts of the kinase that initiates the cascade of phosphorylations. C1 LOS ALAMOS NATL LAB,DIV THEORET,THEORET BIOL & BIOPHYS GRP,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,DEPT MATH & STAT,ALBUQUERQUE,NM 87131. RP Torigoe, C (reprint author), NIAMSD,ARTHRITIS & RHEUMATISM BRANCH,NIH,BETHESDA,MD 20892, USA. FU NIGMS NIH HHS [GM35556, R01 GM035556, R37 GM035556] NR 22 TC 47 Z9 47 U1 0 U2 0 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 FEB 18 PY 1997 VL 94 IS 4 BP 1372 EP 1377 DI 10.1073/pnas.94.4.1372 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ621 UT WOS:A1997WJ62100058 PM 9037060 ER PT J AU Pirot, F Kalia, YN Stinchcomb, AL Keating, G Bunge, A Guy, RH AF Pirot, F Kalia, YN Stinchcomb, AL Keating, G Bunge, A Guy, RH TI Characterization of the permeability barrier of human skin in vivo SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID REFLECTANCE INFRARED-SPECTROSCOPY; HUMAN STRATUM-CORNEUM; PERCUTANEOUS-ABSORPTION; INVIVO; VALIDATION AB Attenuated-total-reflectance Fourier-transform-infrared spectroscopy has been used to rapidly and noninvasively quantify in vivo the uptake of a chemical into the outermost, and least permeable, layer of human skin (the stratum corneum), The objective of the experiment was to develop a general model to predict the rate and extent of chemical absorption for diverse exposure scenarios from simple, and safe, short-duration studies, Measurement of the concentration profile of the chemical in the stratum corneum, and analysis of the data using the unsteady-state diffusion equation, enabled estimation of the permeability coefficient and calculation of the time required to achieve maximal transdermal flux, Validation of the spectroscopic technique employed was established, and quantitation of chemical uptake into the stratum corneum was confirmed independently using trace amounts of radiolabeled chemical in conjunction with liquid scintillation counting and accelerator mass spectrometry. The results presented have pharmacological and toxicological implications, as the technology lends itself both to the prediction of transdermal drug delivery, and the feasibility of this route of administration, and to the assessment of risk after dermal contact with toxic chemicals. C1 UNIV CALIF SAN FRANCISCO,DEPT BIOPHARMACEUT SCI,SAN FRANCISCO,CA 94143. UNIV CALIF SAN FRANCISCO,DEPT PHARMACEUT CHEM,SAN FRANCISCO,CA 94143. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. COLORADO SCH MINES,DEPT CHEM ENGN,GOLDEN,CO 80401. CTR INTERUNIV RECH & ENSEIGNEMENT,F-74166 ARCHAMPS,FRANCE. UNIV GENEVA,FAC SCI,PHARM SECT,PHARM GALEN LAB,CH-1211 GENEVA,SWITZERLAND. RI Guy, Richard/H-3471-2012; Bunge, Annette/A-7995-2012; OI Bunge, Annette/0000-0002-0287-3724; Kalia, Yogeshvar/0000-0001-9049-5489; Guy, Richard/0000-0003-3227-9862 FU NICHD NIH HHS [HD 23010] NR 23 TC 123 Z9 125 U1 1 U2 28 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 FEB 18 PY 1997 VL 94 IS 4 BP 1562 EP 1567 DI 10.1073/pnas.94.4.1562 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ621 UT WOS:A1997WJ62100091 PM 9037093 ER PT J AU Choquette, KD Chow, WW Hadley, GR Hou, HQ Geib, KM AF Choquette, KD Chow, WW Hadley, GR Hou, HQ Geib, KM TI Scalability of small-aperture selectively oxidized vertical cavity lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID SURFACE-EMITTING LASERS; THRESHOLD CURRENT; OXIDATION AB We analyze the threshold properties of small area selectively oxidized vertical cavity lasers. Agreement for threshold gain versus laser size is found using the experimental intrinsic threshold voltage matched with a gain theory, as compared to a two-dimensional optical cavity simulation. Our analysis indicates the increasing threshold current density of small area lasers arises from both increasing threshold gain and the concomitant increasing leakage current. We further show that the optical loss can be reduced for lasers with areas as small as 0.25 mu m(2) while maintaining sufficient transverse optical confinement by displacing the apertures longitudinally away from the cavity and reducing the oxide thickness. (C) 1997 American Institute of Physics. RP Choquette, KD (reprint author), SANDIA NATL LABS,CTR COMPOUND SEMICOND TECHNOL,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 18 TC 61 Z9 61 U1 0 U2 3 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 FEB 17 PY 1997 VL 70 IS 7 BP 823 EP 825 DI 10.1063/1.118234 PG 3 WC Physics, Applied SC Physics GA WH866 UT WOS:A1997WH86600011 ER PT J AU Mazarakis, MG Poukey, JW Rovang, DC Maenchen, JE Cordova, SR Menge, PR Pepping, R Bennett, L Mikkelson, K Smith, DL Halbleib, J Stygar, WA Welch, DR AF Mazarakis, MG Poukey, JW Rovang, DC Maenchen, JE Cordova, SR Menge, PR Pepping, R Bennett, L Mikkelson, K Smith, DL Halbleib, J Stygar, WA Welch, DR TI Pencil-like mm-size electron beams produced with linear inductive voltage adders SO APPLIED PHYSICS LETTERS LA English DT Article AB We present the design, analysis, and results of the high brightness electron beam experiments currently under investigation at Sandia National Laboratories. The anticipated beam parameters an the following: energy 12 MeV, current 35-40 kA, rms radius 0.5 mm, and pulse duration 40 ns full width at half-maximum The accelerator is SABRE, a pulsed linear inductive voltage adder modified to higher impedance, and the electron source is a magnetically immersed foilless electron diode. 20-30 T solenoidal magnets are required to insulate the diode and contain the beam to its extremely small-sized (1 mm) envelope. These experiments are designed to push the technology to produce the highest possible electron current in a submillimeter radius beam. Design, numerical simulations, and experimental results are presented. (C) 1997 American Institute of Physics. C1 MISSION RES CORP, ALBUQUERQUE, NM 87106 USA. RP Mazarakis, MG (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 10 TC 23 Z9 23 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 FEB 17 PY 1997 VL 70 IS 7 BP 832 EP 834 DI 10.1063/1.118217 PG 3 WC Physics, Applied SC Physics GA WH866 UT WOS:A1997WH86600014 ER PT J AU Catledge, SA Vohra, YK Weir, ST Akella, J AF Catledge, SA Vohra, YK Weir, ST Akella, J TI Homoepitaxial diamond films on diamond anvils with metallic probes: The diamond/metal interface up to 74 GPa SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter AB A (100)-oriented natural type-Ia brilliant-cut diamond anvil with thin zirconium electrical probes sputtered onto the culet was coated with an insulating film of diamond using microwave-plasma-enhanced chemical vapour deposition (MPCVD). The critical issue in this high-pressure study is the quality of the homoepitaxial diamond him and its correlation with the mechanical strength of the diamond film/metallic probe interface. We report the first high-pressure study on a homoepitaxial diamond film and underlying zirconium probes to a pressure of 74 GPa. The metallic probes were observed through a transparent lithium fluoride sample with ruby serving as a pressure sensor. After decompression, Raman spectroscopy revealed that the homoepitaxial film was free from deformation and delamination despite the presence of some sp(2)-bonded carbon at the Zr/diamond interface and within the bulk of the him itself. The present study demonstrates that the presence of residual defects and graphitic impurities has no significant effect on high-pressure applications of homoepitaxial diamond films. This opens up new areas of research with diamond anvil cell devices including those of ohmic heating and electrical transport measurements at ultra-high pressures. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Catledge, SA (reprint author), UNIV ALABAMA,DEPT PHYS,BIRMINGHAM,AL 35294, USA. RI Weir, Samuel/H-5046-2012 NR 9 TC 8 Z9 8 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD FEB 17 PY 1997 VL 9 IS 7 BP L67 EP L73 DI 10.1088/0953-8984/9/7/001 PG 7 WC Physics, Condensed Matter SC Physics GA WK005 UT WOS:A1997WK00500001 ER PT J AU Misu, T Nazarewicz, W Aberg, S AF Misu, T Nazarewicz, W Aberg, S TI Deformed nuclear halos SO NUCLEAR PHYSICS A LA English DT Article ID CROSS-SECTIONS; NEUTRON HALO; GROUND-STATE; PROTON-HALO; STABILITY; MASSES; BEAMS; BE-11; MODEL; LINE AB Deformation properties of weakly bound nuclei are discussed in the deformed single-particle model. It is demonstrated that in the limit of a very small binding energy the valence particles in specific orbitals, characterized by a very small projection of single-particle angular momentum onto the symmetry axis of a nucleus, can give rise to the halo structure which is completely decoupled from the rest of the system, The quadrupole deformation of the resulting halo is completely determined by the intrinsic structure of a weakly bound orbital, irrespective of the shape of the core. C1 UNIV WARSAW,INST THEORET PHYS,PL-00681 WARSAW,POLAND. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. LUND INST TECHNOL,DEPT MATH PHYS,S-22100 LUND,SWEDEN. RP Misu, T (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 48 TC 63 Z9 65 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 FEB 17 PY 1997 VL 614 IS 1 BP 44 EP 70 DI 10.1016/S0375-9474(96)00458-7 PG 27 WC Physics, Nuclear SC Physics GA WK812 UT WOS:A1997WK81200002 ER PT J AU Blumenfeld, R AF Blumenfeld, R TI Planar curve representation of many-body systems and dynamics SO PHYSICAL REVIEW LETTERS LA English DT Article AB A method is introduced to represent many-body systems cf arbitrary dimensionality by planar curves. The positions and momenta of the particles are the parameters of a time-dependent nonlinear transformation, which maps the many-body dynamics of the real system to the motion of the curve. The description of the system as a point in a multidimensional phase space is thus replaced by a two-dimensional continuous line. Expressions for the curvature along the curve and the dynamic structure factor are obtained. The formulation holds for Hamiltonian and non-Hamiltonian systems, and two explicit examples are analyzed: harmonic oscillators and a quadratic system. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Blumenfeld, R (reprint author), CAMBRIDGE HYDRODYNAM,POB 1403,PRINCETON,NJ 08542, USA. NR 3 TC 0 Z9 0 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 FEB 17 PY 1997 VL 78 IS 7 BP 1203 EP 1206 DI 10.1103/PhysRevLett.78.1203 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700002 ER PT J AU Baltz, AJ AF Baltz, AJ TI Exact dirac equation calculation of ionization and pair production induced by ultrarelativistic heavy ions SO PHYSICAL REVIEW LETTERS LA English DT Article ID COLLISIONS AB An exact solution of the time-dependent Dirac equation for ionization and pair production induced by ultrarelativistic heavy ion collisions is presented. Exact transition probabilities, equivalent to those that would be obtained in an untruncated basis coupled channels calculation, are presented. Exact bound-electron positron pair production probabilities are calculated to be mostly smaller than those calculated with the same potential in perturbation theory at impact parameters small enough for differences to occur. RP Baltz, AJ (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 7 TC 72 Z9 72 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 FEB 17 PY 1997 VL 78 IS 7 BP 1231 EP 1234 DI 10.1103/PhysRevLett.78.1231 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700009 ER PT J AU Mochrie, SGJ Mayes, AM Sandy, AR Sutton, M Brauer, S Stephenson, GB Abernathy, DL Grubel, G AF Mochrie, SGJ Mayes, AM Sandy, AR Sutton, M Brauer, S Stephenson, GB Abernathy, DL Grubel, G TI Dynamics of block copolymer micelles revealed by x-ray intensity fluctuation spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCATTERING AB We report x-ray intensity fluctuation spectroscopy measurements of the equilibrium dynamics of polymer micelle liquids, composed of polystyrene-polyisoprene block copolymer micelles within a polystyrene homopolymer matrix. The equilibrium dynamics were investigated for times between one and several hundred seconds, and for wave vectors from 0.003 to 0.015 Angstrom(-1), far beyond wave vectors that can be studied with visible light. A wave-vector-dependent diffusion coefficient is found. C1 MCGILL UNIV,DEPT PHYS,MONTREAL,PQ,CANADA. ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. RP Mochrie, SGJ (reprint author), MIT,CTR MAT SCI & ENGN,CAMBRIDGE,MA 02139, USA. RI Abernathy, Douglas/A-3038-2012 OI Abernathy, Douglas/0000-0002-3533-003X NR 12 TC 114 Z9 115 U1 5 U2 17 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 FEB 17 PY 1997 VL 78 IS 7 BP 1275 EP 1278 DI 10.1103/PhysRevLett.78.1275 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700020 ER PT J AU Kelly, PJ Dekker, JP Stumpf, R AF Kelly, PJ Dekker, JP Stumpf, R TI Theoretical prediction of the structure of insulating YH3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID DENSITY-FUNCTIONAL THEORY; BAND-GAPS; PSEUDOPOTENTIALS; SEMICONDUCTORS; ELECTRON; YTTRIUM AB Density functional calculations of the total energy have been used to determine minimum energy structures for YH3. Small, symmetry lowering displacements of the hydrogen atoms lead to a structure with an energy which is lower than that of any other structure considered so far and the opening of a large band gap sufficient to explain the recently observed metal-insulator transition in the YHx system. C1 FREE UNIV AMSTERDAM,FAC PHYS & ASTRON,NL-1081 HV AMSTERDAM,NETHERLANDS. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Kelly, PJ (reprint author), PHILIPS RES LABS,PROF HOLSTLAAN 4,NL-5656 AA EINDHOVEN,NETHERLANDS. RI Kelly, Paul/G-4210-2010 OI Kelly, Paul/0000-0001-9040-1868 NR 28 TC 118 Z9 119 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 FEB 17 PY 1997 VL 78 IS 7 BP 1315 EP 1318 DI 10.1103/PhysRevLett.78.1315 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700030 ER PT J AU Kner, P BarAd, S Marquezini, MV Chemla, DS Schafer, W AF Kner, P BarAd, S Marquezini, MV Chemla, DS Schafer, W TI Magnetically enhanced exciton-exciton correlations in semiconductors SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM-WELLS; FANO RESONANCES; LIGHT; DYNAMICS; MEDIA; BEATS; HOLE AB We present investigations of fs time resolved coherent wave mixing under high magnetic field. Our experiments reveal a new regime at high magnetic field and low excitation density dominated by the Coulomb interaction. This regime is inconsistent with the semiconductor Bloch equations. A model which includes exciton-exciton correlation successfully describes many features of this regime. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. HOCHSTLEISTUNGSRECHENZENTRUM FORSCHUNGSZENTRUM JU,JULICH,GERMANY. RP Kner, P (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 24 TC 108 Z9 108 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 FEB 17 PY 1997 VL 78 IS 7 BP 1319 EP 1322 DI 10.1103/PhysRevLett.78.1319 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700031 ER PT J AU Weitering, HH Shi, X Johnson, PD Chen, J DiNardo, NJ Kempa, K AF Weitering, HH Shi, X Johnson, PD Chen, J DiNardo, NJ Kempa, K TI Mott insulating ground state on a triangular surface lattice SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALKALI-METALS; MODEL; ANTIFERROMAGNET; METALLIZATION; GAAS(110) AB Momentum-resolved direct and inverse photoemission spectra of the K/Si(111)-(root 3 x root 3)R30 degrees-B interface reveals the presence of strongly localized surface states, The K overlayer remains nonmetallic up to the saturation coverage. This system most likely presents the first experimental realization of a frustrated spin 1/2 Heisenberg antiferromagnet on a two-dimensional triangular lattice. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV PENN,DEPT PHYS,PHILADELPHIA,PA 19104. DREXEL UNIV,DEPT PHYS & ATMOSPHER SCI,PHILADELPHIA,PA 19104. UNIV PENN,DEPT MAT SCI & ENGN,PHILADELPHIA,PA 19104. BOSTON COLL,DEPT PHYS,CHESTNUT HILL,MA 02167. RP Weitering, HH (reprint author), UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996, USA. NR 26 TC 78 Z9 78 U1 1 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 17 PY 1997 VL 78 IS 7 BP 1331 EP 1334 DI 10.1103/PhysRevLett.78.1331 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700034 ER PT J AU Shi, ZP Fishman, RS AF Shi, ZP Fishman, RS TI Interplay between spin-density wave and proximity magnetic layers SO PHYSICAL REVIEW LETTERS LA English DT Article ID CHROMIUM-ALLOYS; ANTIFERROMAGNETISM; SUPERLATTICES; MULTILAYERS; MOMENTS; FE(100) AB A spin-density wave (SDW) is shown to mediate a strongly temperature-dependent magnetic coupling between magnetic proximity layers. For parallel or antiparallel moments in the proximity layers, the order parameters of the SDW oscillate as a function of the spacer thickness with a two monolayer period. The SDW phase transition between incommensurate and commensurate phases can be controlled by flipping the magnetization of one of the proximity layers. RP Shi, ZP (reprint author), OAK RIDGE NATL LAB,DIV SOLID STATE,POB 2008,OAK RIDGE,TN 37831, USA. RI Fishman, Randy/C-8639-2013 NR 22 TC 47 Z9 47 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 FEB 17 PY 1997 VL 78 IS 7 BP 1351 EP 1354 DI 10.1103/PhysRevLett.78.1351 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700039 ER PT J AU BarAd, S Marquezini, MV Mukamel, S Chemla, DS AF BarAd, S Marquezini, MV Mukamel, S Chemla, DS TI Quantum confined Fano interference SO PHYSICAL REVIEW LETTERS LA English DT Article ID RESONANCES; WELLS AB We study the transition from a dense continuum to a sparse quasicontinuum in the Fano problem. Transmission measurements on epitaxial layers of GaAs in a high magnetic field and calculations of the optical absorption show how the Fano interference disappears as quantum confinement discretizes the continuum states. The transition between quasi-one-dimensional and quasi-zero-dimensional systems occurs at length scales which are unusually large for optical experiments. C1 UNIV CALIF BERKELEY, DIV MAT SCI, LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 18 TC 46 Z9 46 U1 0 U2 3 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 FEB 17 PY 1997 VL 78 IS 7 BP 1363 EP 1366 DI 10.1103/PhysRevLett.78.1363 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700042 ER PT J AU You, H Nagy, Z Huang, K AF You, H Nagy, Z Huang, K TI X-ray scattering study of porous silicon growth during anodic dissolution SO PHYSICAL REVIEW LETTERS LA English DT Article ID TRANSMISSION GEOMETRY; REFLECTIVITY; SURFACE; LUMINESCENCE; MECHANISM AB Formation of porous silicon at the surface of p(+)-type silicon in HF solution has been investigated in situ during anodic dissolution by x-ray reflectivity and diffuse-scattering measurements. Rings of diffuse scattering around Bragg reflections indicate a pare-pore distribution controlled by a space-charge region at the silicon/solution interface. Experimental results for evolution of the interface during the dissolution process are described by an Edward-Wilkinson-type growth model. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. APPL MAT INC,SANTA CLARA,CA 95054. RP You, H (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI You, Hoydoo/A-6201-2011 OI You, Hoydoo/0000-0003-2996-9483 NR 24 TC 18 Z9 19 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 FEB 17 PY 1997 VL 78 IS 7 BP 1367 EP 1370 DI 10.1103/PhysRevLett.78.1367 PG 4 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700043 ER PT J AU Cossairt, JD Marshall, ET AF Cossairt, JD Marshall, ET TI Biological effects of stellar collapse neutrinos - Comment SO PHYSICAL REVIEW LETTERS LA English DT Article ID INDUCTION; DAMAGE; IONS RP Cossairt, JD (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. FU NIDCR NIH HHS [DE-AC02-76CH03000] NR 12 TC 6 Z9 6 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 FEB 17 PY 1997 VL 78 IS 7 BP 1394 EP 1394 DI 10.1103/PhysRevLett.78.1394 PG 1 WC Physics, Multidisciplinary SC Physics GA WH917 UT WOS:A1997WH91700052 PM 11541191 ER PT J AU Keblinski, P Phillpot, SR Wolf, D Gleiter, H AF Keblinski, P Phillpot, SR Wolf, D Gleiter, H TI Thermodynamically stable amorphous intergranular films in nanocrystalline silicon SO PHYSICS LETTERS A LA English DT Article DE silicon; nanocrystalline; amorphous ID MOLECULAR-DYNAMICS AB Molecular-dynamics simulations were used to synthesize fully dense nanocrystalline silicon by crystallization from the melt. The equilibrium structures of the highly constrained grain boundaries and grain junctions in these metastable microstructures are found to be highly disordered and similar to the structure of amorphous silicon, These results demonstrate that in thermodynamic equilibrium nanocrystalline silicon may be treated as a two phase system composed of crystalline grain interiors that are connected by an amorphous intergranular phase. C1 FORSCHUNGSZENTRUM KARLSRUHE,D-76021 KARLSRUHE,GERMANY. RP Keblinski, P (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Phillpot, Simon/J-9117-2012; OI Phillpot, Simon/0000-0002-7774-6535 NR 18 TC 17 Z9 18 U1 0 U2 6 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 FEB 17 PY 1997 VL 226 IS 3-4 BP 205 EP 211 DI 10.1016/S0375-9601(96)00925-5 PG 7 WC Physics, Multidisciplinary SC Physics GA WH584 UT WOS:A1997WH58400013 ER PT J AU Zavalij, PY Chirayil, T Whittingham, MS Pecharsky, VK Jacobson, RA AF Zavalij, PY Chirayil, T Whittingham, MS Pecharsky, VK Jacobson, RA TI A new decavanadate with mixed cations, [Li(H2O)(4)](2)[N(CH3)(4)](4)[V10O28]center dot 4H(2)O SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article AB The title compound, tetrakis(tetramethylammonium) bis(lithium tetrahydrate) decavanadate tetrahydrate, (C4H12N)(4)[Li(H2O)(4)](2)[V10O28].4H(2)O, was synthesized and found to crystallize in the triclinic system (space group ). The centrosymmetric [V10O28](6-) polyanions form layers in the ac plane by hydrogen bonding with tetrahedral [Li(H2O)(4)](+) cations and water molecules of crystallization. The tetramethylammonium cations fill the space between the layers. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP Zavalij, PY (reprint author), SUNY BINGHAMTON,MAT RES CTR,BINGHAMTON,NY 13902, USA. RI Zavalij, Peter/H-3817-2012 OI Zavalij, Peter/0000-0001-5762-3469 NR 11 TC 16 Z9 16 U1 1 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD FEB 15 PY 1997 VL 53 BP 170 EP 171 DI 10.1107/S0108270196013480 PN 2 PG 2 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WL369 UT WOS:A1997WL36900004 ER PT J AU Rabinovich, D Schimek, GL Pennington, WT Nielsen, JB Abney, KD AF Rabinovich, D Schimek, GL Pennington, WT Nielsen, JB Abney, KD TI Tetrachlorobis(N,N,N'N'-tetramethylethylenediamine-N,N') thorium(IV) SO ACTA CRYSTALLOGRAPHICA SECTION C-CRYSTAL STRUCTURE COMMUNICATIONS LA English DT Article ID COMPLEXES AB The title compound, [ThCl4(C6H16N2)(2)], displays an approximate dodecahedral geometry in the solid state, with the Th atom binding to four Cl ligands and to the four N atoms of two tetramethylethylenediamine ligands. The Th-Cl and Th-N distances are in the ranges 2.683 (3)-2.692 (3) and 2.800 (7)-2.825 (9) Angstrom, respectively. C1 CLEMSON UNIV,DEPT CHEM,CLEMSON,SC 29634. RP Rabinovich, D (reprint author), LOS ALAMOS NATL LAB,CST-11,MAIL STOP J514,LOS ALAMOS,NM 87545, USA. NR 14 TC 5 Z9 5 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-2701 J9 ACTA CRYSTALLOGR C JI Acta Crystallogr. Sect. C-Cryst. Struct. Commun. PD FEB 15 PY 1997 VL 53 BP 191 EP 193 DI 10.1107/S0108270196012796 PN 2 PG 3 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WL369 UT WOS:A1997WL36900014 ER PT J AU Tan, HD Yeung, ES AF Tan, HD Yeung, ES TI Integrated on-line system for DNA sequencing by capillary electrophoresis: From template to called bases SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYMERASE CHAIN-REACTION; GEL-ELECTROPHORESIS; AMPLIFICATION; PURIFICATION; FLUORESCENCE; QUANTITATION; PERFORMANCE; SEPARATION; FRAGMENTS; TUBES AB An integrated on-line prototype for coupling a microreactor to capillary electrophoresis for DNA sequencing has been demonstrated. A dye-labeled terminator cycle-sequencing reaction is performed in a fused-silica capillary. Subsequently, the sequencing ladder is directly injected into a size-exclusion chromatographic column operated at similar to 95 degrees C for purification. On-line injection to a capillary for electrophoresis is accomplished at a junction set at similar to 70 degrees C. High temperature at the purification column and injection junction prevents the renaturation of DNA fragments during on-line transfer without affecting the separation. The high solubility of DNA in and the relatively low ionic strength of 1xTE buffer permit both effective purification and electrokinetic injection of the DNA sample. The system is compatible with highly efficient separations by a replaceable poly(ethylene oxide) polymer solution in uncoated capillary tubes. Future automation and adaptation to a multiple-capillary array system should allow high-speed, high-throughput DNA sequencing from templates to called bases in one step. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 32 TC 41 Z9 43 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 FEB 15 PY 1997 VL 69 IS 4 BP 664 EP 674 DI 10.1021/ac960892e PG 11 WC Chemistry, Analytical SC Chemistry GA WH357 UT WOS:A1997WH35700020 ER PT J AU Ting, EY Porter, MD AF Ting, EY Porter, MD TI Separations of corticosteroids using electrochemically modulated liquid chromatography: Selectivity enhancements at a porous graphitic carbon stationary phase SO ANALYTICAL CHEMISTRY LA English DT Article ID POLYPYRROLE; ELECTRODES; EMLC AB Electrochemically modulated liquid chromatography has been applied to the separation of a mixture of structurally similar corticosteroids (i.e., prednisone, prednisolone, cortisone, and hydrocortisone) using a porous graphitic carbon stationary phase. Changes in the voltage applied to the column markedly affected the efficiency as well as the elution order of the separation, with the mixture fully resolved at large negative values of applied potential. Mechanistic aspects in terms of the influence of changes in the applied voltage on the extent of the interactions between these analytes and the stationary phase are briefly discussed. C1 US DOE,AMES LAB,MICROANALYT INSTRUMENTAT CTR,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. NR 19 TC 34 Z9 34 U1 1 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 FEB 15 PY 1997 VL 69 IS 4 BP 675 EP 678 DI 10.1021/ac960880t PG 4 WC Chemistry, Analytical SC Chemistry GA WH357 UT WOS:A1997WH35700021 ER PT J AU Nelson, DO Speed, TP Yu, B AF Nelson, DO Speed, TP Yu, B TI The limits of random fingerprinting SO GENOMICS LA English DT Article ID CONSTRUCTION; LIBRARIES AB Various random fingerprinting methods are sometimes used to detect overlap between pairs of clones as a first step toward producing a minimal tiling path of clones for subsequent mapping and sequencing efforts. This paper evaluates and compares various statistical procedures for detecting pairwise overlap between clones when the fingerprints arise from any random process meeting simple, plausible assumptions about the relationship between overlap and the resulting fingerprint. Examples of such random processes include, but are not limited to, large-scale hybridization procedures designed to prepare thing paths of clones for subsequent large-scale genomic sequencing. Our goals are to assess how well random fingerprinting can possibly detect overlap, to assess the effects of inevitable fingerprinting errors on statistical detection, to determine how one can make the best use of the data random fingerprinting provides, and to evaluate how well simple, heuristic techniques for overlap detection compare to more complex, likelihood-based approaches. The paper provides a quantitative assessment of the ability of any random fingerprinting procedure to detect various proportions of clonal overlap and shows the extent to which a small amount of experimental error will vitiate the performance of such techniques. The paper outlines a simple approximation method for constructing Bayesian overlap detectors, while concluding that detectors constructed from linear combinations of fingerprint data can be designed that will perform nearly as well as more complex, likelihood-based approaches. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,DEPT STAT,BERKELEY,CA 94720. RP Nelson, DO (reprint author), LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,BIOL & BIOTECHNOL RES PROGRAM,BOX 808,LIVERMORE,CA 94551, USA. RI Speed, Terence /B-8085-2009 OI Speed, Terence /0000-0002-5403-7998 NR 9 TC 1 Z9 1 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 FEB 15 PY 1997 VL 40 IS 1 BP 1 EP 12 DI 10.1006/geno.1996.4537 PG 12 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WJ336 UT WOS:A1997WJ33600001 PM 9070913 ER PT J AU Elphic, RC Thomsen, MF Borovsky, JE AF Elphic, RC Thomsen, MF Borovsky, JE TI The fate of the outer plasmasphere SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MODEL; SHEET AB Both the solar wind and the ionosphere contribute to Earth's magnetospheric plasma environment. However, it is not widely appreciated that the plasmasphere is a large reservoir of ionospheric ions that can be tapped to populate the plasma sheet. We employ empirical models of high-latitude ionospheric convection and the geomagnetic field to describe the transport of outer plasmasphere flux tubes from the dayside, over the polar cap and into the magnetotail during the early phases of a geomagnetic storm. We calculate that this process can give rise to high densities of cold plasma in the magnetotail lobes and in the near-Earth plasma sheet during times of enhanced geomagnetic activity, and especially during storms. This model can help explain both polar cap ionization patches and the presence of cold flowing ions downtail. RP Elphic, RC (reprint author), LOS ALAMOS NATL LAB,ATMOSPHER & SPACE SCI GRP,MS D466,LOS ALAMOS,NM 87545, USA. NR 21 TC 57 Z9 57 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 15 PY 1997 VL 24 IS 4 BP 365 EP 368 DI 10.1029/97GL00141 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WJ181 UT WOS:A1997WJ18100004 ER PT J AU Sluiter, M Takahashi, M Kawazoe, Y AF Sluiter, M Takahashi, M Kawazoe, Y TI Theoretical study of phase stability in LaNi5-LaCo5 alloys SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE La-Co-Ni alloys; phase diagram; metal hydrides; LaNi5; electronic total energy calculations ID LANI5 AB The phase stability of LaNi5-LaCo5 alloys with the CaCu5 type crystal structure (P6/mmm) has been investigated from first principles. The alloy is computed to form a continuous solid solution. Ferromagnetism increases with Co concentration, in accordance with experimental observations. It is found that Co impurities in LaNi5 have a strong preference for the three-fold degenerate non-basal sites (Ni-II, 3g). This preference persists at high temperatures, as has been observed in actual alloys by neutron scattering, The softness in the c direction is shown to increase with increasing Co concentration in the alloy. C1 GUNMA UNIV,FAC ENGN,KIRYU,GUMMA 376,JAPAN. TOHOKU UNIV,INST MAT RES,SENDAI,MIYAGI 98077,JAPAN. RP Sluiter, M (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. RI Kawazoe, Yoshiyuki/C-2998-2011; Sluiter, Marcel/E-6086-2010 OI Sluiter, Marcel/0000-0002-6514-4318 NR 35 TC 23 Z9 23 U1 0 U2 7 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 FEB 15 PY 1997 VL 248 IS 1-2 BP 90 EP 97 DI 10.1016/S0925-8388(96)02615-1 PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA WX996 UT WOS:A1997WX99600016 ER PT J AU Knepfler, CA Faber, KT Weertman, J Olson, GB Hubbard, CR Cavin, OB Packen, N AF Knepfler, CA Faber, KT Weertman, J Olson, GB Hubbard, CR Cavin, OB Packen, N TI High temperature stability and thermal expansion behavior of molybdenum-chromium M2C carbides SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE M2C carbides; thermal expansion; non-stoichiometry; high-temperature X-ray diffraction AB The thermal expansion of molybdenum-chromium M2C carbides has been studied over the temperature range from room temperature to 900 degrees C using high-temperature X-ray diffraction. Hyperstoichiometric carbides demonstrated hysteretic thermal expansion/contraction as excess carbon was lost upon heating above 750 degrees C in an inert environment. Coefficients of thermal expansion of both the a and c axes increase linearly with chromium content. C1 NORTHWESTERN UNIV,ROBERT R MCCORMICK SCH ENGN & APPL SCI,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. RI Faber, Katherine/B-6741-2009; Weertman, Johannes/B-7539-2009; Olson, Gregory/B-7529-2009 NR 9 TC 1 Z9 1 U1 3 U2 7 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 FEB 15 PY 1997 VL 248 IS 1-2 BP 139 EP 142 DI 10.1016/S0925-8388(96)02442-5 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA WX996 UT WOS:A1997WX99600024 ER PT J AU Ferer, M Smith, DH AF Ferer, M Smith, DH TI A simple model of the adhesive failure of a layer: Cohesive effects SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FRACTURE; DYNAMICS; CRACKS AB A fine-scale model is developed for the removal of an adhesive layer by a uniform stress. The initial motivation of this modeling project was a description of the removal of a layer of filter cake from cylindrical filters by backpulse cleaning. The model includes the bonding forces of adhesion between the layer and a substrate, as well as the farces of cohesion between imaginary ''gridblocks'' within the layer. For stresses greater than a threshold value, some of the layer is removed, with the fraction removed depending upon the stress, the average adhesive and cohesive forces, and the distribution of these forces about their average. The cohesive forces reduce the threshold well below the average strength of the adhesive force, because they increase the stress near broken adhesive bonds. The cohesive forces also sharpen the threshold in the cleaning pressure significantly, so that the threshold is very much sharper than the distribution of adhesive strengths, For moderate filter cake thickness (moderately strong cohesive forces), the threshold becomes steplike, with no cleaning just below the threshold and complete cleaning at the threshold and above. The model also provides the pressure dependence of the size and shape distributions for the fragments of the filter cake layer removed from the filter, enabling the model to address questions of cleaning efficiency, ''patchy cleaning,'' re-entrainment, and trapping of large cake-fragments in the filter vessel. (C) 1997 American Institute of Physics. C1 US DOE,MORGANTOWN ENERGY TECHNOL CTR,MORGANTOWN,WV 26507. RP Ferer, M (reprint author), W VIRGINIA UNIV,DEPT PHYS,POB 6315,MORGANTOWN,WV 26506, USA. NR 31 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD FEB 15 PY 1997 VL 81 IS 4 BP 1737 EP 1744 DI 10.1063/1.365272 PG 8 WC Physics, Applied SC Physics GA WH339 UT WOS:A1997WH33900020 ER PT J AU Niles, DW Herdt, G AlJassim, M AF Niles, DW Herdt, G AlJassim, M TI An x-ray photoelectron spectroscopy investigation of O impurity chemistry in CdS thin films grown by chemical bath deposition SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CADMIUM; SPECTRA; STATES; OXYGEN AB We used x-ray photoelectron spectroscopy to investigate the chemistry of O impurity atoms in CdS thin films grown for photovoltaic purposes by chemical-bath deposition (CBD). We compared the Cd 3d photoline, O 1 s photoline, Cd MNN Auger line, and O KLL Auger line taken from a CBD CdS thin him, CdS single-crystal reference, Cd metal reference, CdO reference, and Cd(OH)(2) reference. This comparison showed that the O present in thin-film CBD CdS is a manifestation of H2O incorporated into the film during the CBD growth. Ar+ ion sputtering, a technique frequently used in thin-film analyses, preferentially removed S from the CBD CdS thin film and created CdS1-xOx (x similar to 0.04) in the surface region from the incorporated O impurity. (C) 1997 American Institute of Physics. RP Niles, DW (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 21 TC 48 Z9 50 U1 3 U2 14 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 FEB 15 PY 1997 VL 81 IS 4 BP 1978 EP 1984 DI 10.1063/1.364054 PG 7 WC Physics, Applied SC Physics GA WH339 UT WOS:A1997WH33900056 ER PT J AU Hu, Y Jiang, JW Liu, HL Prausnitz, JM AF Hu, Y Jiang, JW Liu, HL Prausnitz, JM TI Thermodynamic properties of aqueous solutions: Nonsymmetric sticky electrolytes with overlap between ions in the mean-spherical approximation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID ASYMMETRIC ELECTROLYTES; ADHESIVE INTERACTIONS; DIPOLAR DUMBBELLS; WEAK ELECTROLYTES; CLUSTER THEORY; HARD-SPHERES; MODEL; ASSOCIATION; EQUILIBRIUM AB Based on a sticky-electrolyte model, the Ornstein-Zernike integral equation is solved for nonsymmetric electrolytes with stickiness between ions at various distances equal to or less than the collision diameter. The hypernetted chain or Percus-Yevick approximation is used for the closure inside the hard core, while the mean-spherical approximation for electrostatic interactions is used for the closure outside the hard core. Expressions for correlation functions and thermodynamic properties in term of the sticky parameters are derived. Numerical results are presented for various cases. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Hu, Y (reprint author), E CHINA UNIV SCI & TECHNOL,THERMODYNAM RES LAB,SHANGHAI 200237,PEOPLES R CHINA. RI JIANG, Jianwen/G-1505-2013; OI Jiang, Jianwen/0000-0003-1310-9024 NR 22 TC 9 Z9 10 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 FEB 15 PY 1997 VL 106 IS 7 BP 2718 EP 2727 DI 10.1063/1.473350 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WH024 UT WOS:A1997WH02400020 ER PT J AU Anderson, RJ Walker, RL Hird, DW Blanchard, PC AF Anderson, RJ Walker, RL Hird, DW Blanchard, PC TI Case-control study of an outbreak of clinical disease attributable to Salmonella menhaden infection in eight dairy herds SO JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION LA English DT Article DE bovine species; epidemiology; Salmonella menhaden ID BOVINE SALMONELLOSIS AB Objective--To identify risk factors associated with Salmonella menhaden associated disease in adult dairy cows during an outbreak in California. Design-Case-control study. Sample Population--8 case dairies that had greater than or equal to 1 adult animal that had clinical signs of salmonellosis and from which S menhaden was isolated and 22 control dairies, 16 of which were matched on the basis of herd size and county and 6 of which were matched on the basis of herd size, county, and breed (Jersey). Procedure--A questionnaire was developed and reviewed with the herdsman or owner of each dairy. Primary areas of concern were herd management, disease characteristics, and feed-related information. Results--Use of 1 particular feed mill and feeding animal fat were significant risk factors for clinical disease attributable to S menhaden infection. Clinical Implications--Feed should not be overlooked as a potential source of Salmonella organisms in dairy herds. C1 UNIV CALIF DAVIS,SCH VET MED,DEPT MED & EPIDEMIOL,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,CALIF VET DIAGNOST LAB SYST,DAVIS,CA 95616. CALIF VET DIAGNOST LAB SYST,TULARE,CA 93274. RP Anderson, RJ (reprint author), CALIF DEPT FOOD & AGR,ANIM HLTH BRANCH,1620 N CARPENTER RD,STE D-48,MODESTO,CA 95351, USA. NR 17 TC 35 Z9 36 U1 1 U2 4 PU AMER VETERINARY MEDICAL ASSOC PI SCHAUMBURG PA 1931 N MEACHAM RD SUITE 100, SCHAUMBURG, IL 60173-4360 SN 0003-1488 J9 J AM VET MED ASSOC JI J. Am. Vet. Med. Assoc. PD FEB 15 PY 1997 VL 210 IS 4 BP 528 EP & PG 4 WC Veterinary Sciences SC Veterinary Sciences GA WG855 UT WOS:A1997WG85500018 PM 9040841 ER PT J AU Burton, H AF Burton, H TI Albert Einstein - Folsing,A SO LIBRARY JOURNAL LA English DT Book Review RP Burton, H (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BOWKER MAGAZINE GROUP CAHNERS MAGAZINE DIVISION PI NEW YORK PA 249 W 17TH ST, NEW YORK, NY 10011 SN 0363-0277 J9 LIBR J JI Libr. J. PD FEB 15 PY 1997 VL 122 IS 3 BP 159 EP 159 PG 1 WC Information Science & Library Science SC Information Science & Library Science GA WG362 UT WOS:A1997WG36200203 ER PT J AU He, YR Rapp, RA Tortorelli, PF AF He, YR Rapp, RA Tortorelli, PF TI Oxidation-resistant Ge-doped silicide coating on Cr-Cr2Nb alloys by pack cementation SO MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING LA English DT Article DE alloys; diffusion coating; morphology; oxidation ID INTERMETALLICS; BEHAVIOR AB The halide-activated pack cementation process was modified to produce a Ge-doped silicide diffusion coating on Cr-Cr2Nb alloys in a single processing step. The morphology and composition of the coating depended both on the pack composition and processing schedule and also on the composition and microstructure of the substrate. Higher Ge content in the pack suppressed the formation of CrSi2 and reduced the growth kinetics of the coating. Ge was not homogeneously distributed in the coatings. Under cyclic and isothermal oxidation conditions, the Ge-doped silicide coating protected the Cr-Nb alloys from significant oxidation and from pesting by the formation of a Ge-doped silica film. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP He, YR (reprint author), OHIO STATE UNIV,DEPT MAT SCI & ENGN,116 W 19TH AVE,COLUMBUS,OH 43210, USA. NR 32 TC 15 Z9 20 U1 1 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0921-5093 J9 MAT SCI ENG A-STRUCT JI Mater. Sci. Eng. A-Struct. Mater. Prop. Microstruct. Process. PD FEB 15 PY 1997 VL 222 IS 2 BP 109 EP 117 DI 10.1016/S0921-5093(96)10516-5 PG 9 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WP119 UT WOS:A1997WP11900003 ER PT J AU Raja, MC ZevinSonkin, D Shwartzburd, J Rozovskaya, TA Sobolev, IA Chertkov, O Ramanathan, V Lvovsky, L Ulanovsky, LE AF Raja, MC ZevinSonkin, D Shwartzburd, J Rozovskaya, TA Sobolev, IA Chertkov, O Ramanathan, V Lvovsky, L Ulanovsky, LE TI DNA sequencing using differential extension with nucleotide subsets (DENS) SO NUCLEIC ACIDS RESEARCH LA English DT Article ID PRIMER WALKING; MODULAR PRIMERS; HEXAMERS; LIGATION; LIBRARY; STRINGS AB Here we describe template directed enzymatic synthesis of unique primers, avoiding the chemical synthesis step in primer walking, We have termed this conceptually new technique DENS (differential extension with nucleotide subsets), DENS works by selectively extending a short primer, making it a long one at the intended site only, The procedure starts with a limited initial extension of the primer (at 20-30 degrees C) in the presence of only two out of the four possible dNTPs, The primer is extended by 6-9 bases or longer at the intended priming site, which is deliberately selected, (as is the two-dNTP set), to maximize the extension length, The subsequent termination reaction at 60-65 degrees C then accepts the extended primer at the intended site, but not at alternative sites, where the initial extension (if any) is generally much shorter DENS allows the use of primers as long as 8mers (degenerate in two positions) which prime much more strongly than modular primers involving 5-7mers and which (unlike the latter) can be used with thermostable polymerases, thus allowing cycle-sequencing with dye-terminators compatible with Tag DNA polymerase, as well as making double-stranded DNA sequencing more robust. C1 ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,ARGONNE,IL 60439. WEIZMANN INST SCI,DEPT BIOL STRUCT,IL-76100 REHOVOT,ISRAEL. NR 19 TC 4 Z9 4 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0305-1048 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD FEB 15 PY 1997 VL 25 IS 4 BP 800 EP 805 DI 10.1093/nar/25.4.800 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WJ770 UT WOS:A1997WJ77000017 PM 9016632 ER PT J AU Barsky, D Colvin, ME Zon, G Gryaznov, SM AF Barsky, D Colvin, ME Zon, G Gryaznov, SM TI Hydration effects on the duplex stability of phosphoramidate DNA-RNA oligomers SO NUCLEIC ACIDS RESEARCH LA English DT Article ID MOLECULAR-DYNAMICS SIMULATIONS; SOLVENT; ENERGY AB Recent studies on uniformly modified oligonucleotides containing 3'-NHP(O)(O-)O-5' internucleoside linkages (3' amidate) and alternatively modified oligonucleotides containing 3'-O(O-)(O)PNH-5' internucleoside linkages (5' amidate) have shown that 3' amidate duplexes, formed with DNA or RNA complementary strands, are more stable in water than those of the corresponding phosphodiesters. In contrast, 5' amidates do not form duplexes at all. There is no steric reason that the 5' amidate duplex should not form. We demonstrate that these differences arise from differential solvation of the sugar-phosphate backbones, By molecular dynamics calculations on models of 10mer single-stranded DNA and double-stranded DNA-RNA molecules, both with and without the phosphoramidate backbone modifications, we show that the single-stranded 3' amidate and 5' amidate backbones are equally well solvated, but the 5' amidate backbone is not adequately solvated in an A-form duplex, These results are supported by quantum chemical free energy of solvation calculations which show that the 3' amidate backbone is favored relative to the 5' amidate backbone. C1 LYNX THERAPEUT INC, HAYWARD, CA 94545 USA. RP SANDIA NATL LABS, MS 9214, LIVERMORE, CA 94551 USA. NR 21 TC 21 Z9 21 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0305-1048 EI 1362-4962 J9 NUCLEIC ACIDS RES JI Nucleic Acids Res. PD FEB 15 PY 1997 VL 25 IS 4 BP 830 EP 835 DI 10.1093/nar/25.4.830 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WJ770 UT WOS:A1997WJ77000021 PM 9016634 ER PT J AU Yatsenko, LP Unanyan, RG Bergmann, K Halfmann, T Shore, BW AF Yatsenko, LP Unanyan, RG Bergmann, K Halfmann, T Shore, BW TI Population transfer through the continuum using laser-controlled Stark shifts SO OPTICS COMMUNICATIONS LA English DT Article ID MULTILEVEL SYSTEMS; MAGNETIC SUBLEVELS; PHOTON IONIZATION; ATOMS AB We show, through analysis and numerical modeling of hydrogen and sodium, that it should be possible to transfer atomic population, with high probability, using a delayed-pulse two-photon Raman transition in which intermediate states are in the ionization continuum. We propose using auxiliary laser pulses to overcome dynamic Stark shifts that would otherwise prevent population transfer. We find that, even without such auxiliary pulses, population transfer can be improved by tuning the carrier frequencies away from the two-photon Raman resonance condition. Our computations for hydrogen predict nearly 85 percent population transfer. C1 UKRAINIAN ACAD SCI,INST PHYS,UA-252650 KIEV,UKRAINE. ARMENIAN ACAD SCI,INST PHYS RES,ASHTARAK 378410,ARMENIA. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Yatsenko, LP (reprint author), UNIV KAISERSLAUTERN,FACHBEREICH PHYS,D-67653 KAISERSLAUTERN,GERMANY. RI Halfmann, Thomas/O-4588-2014; BERGMANN, KLAAS/D-5543-2011 OI Halfmann, Thomas/0000-0002-1222-2669; NR 22 TC 58 Z9 58 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD FEB 15 PY 1997 VL 135 IS 4-6 BP 406 EP 412 DI 10.1016/S0030-4018(96)00630-X PG 7 WC Optics SC Optics GA WD757 UT WOS:A1997WD75700039 ER PT J AU Stuart, BC Perry, MD Miller, J Tietbohl, G Herman, S Britten, JA Brown, C Pennington, D Yanovsky, V Wharton, K AF Stuart, BC Perry, MD Miller, J Tietbohl, G Herman, S Britten, JA Brown, C Pennington, D Yanovsky, V Wharton, K TI 125-TW Ti:sapphire/Nd:glass laser system SO OPTICS LETTERS LA English DT Article ID CHIRPED-PULSE-AMPLIFICATION; GENERATION; TERAWATT AB We have demonstrated a Ti:sapphire/Nd:glass laser system that produces up to 51 J of energy in 395-fs pulses (125 TW). Focusing at f/3 to a 2.5-times diffraction-limited spot results in a peak irradiance greater than 10(20) W/cm(2). Our 40-cm-diameter gold diffraction gratings have a damage threshold of 0.42 J/cm(2) for 320-fs pulses. (C) 1997 Optical Society of America. RP Stuart, BC (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. RI Yanovsky, Victor/B-5899-2008; Stuart, Brent/K-4988-2015 NR 19 TC 40 Z9 44 U1 2 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 FEB 15 PY 1997 VL 22 IS 4 BP 242 EP 244 DI 10.1364/OL.22.000242 PG 3 WC Optics SC Optics GA WH246 UT WOS:A1997WH24600016 PM 18183163 ER PT J AU Krumbugel, MA Sweetser, JN Fittinghoff, DN DeLong, KW Trebino, R AF Krumbugel, MA Sweetser, JN Fittinghoff, DN DeLong, KW Trebino, R TI Ultrafast optical switching by use of fully phase-matched cascaded second-order nonlinearities in a polarization-gate geometry SO OPTICS LETTERS LA English DT Article ID 2ND-HARMONIC GENERATION; MODULATION AB We show that cascaded second-order nonlinear-optical processes can occur in a convenient polarization-gate beam geometry. Our arrangement uses type II phase matching, and both individual second-order processes (upconversion and downconversion) are simultaneously phase matched. This geometry can be applied to efficient ultrafast optical switching. With a beta-barium berate crystal and lightly focused 250-fs, 7.3-mu J pulses, we achieve a switching efficiency of 15% and an on-off ratio of 3 x 10(4) on a pulse-length-limited time scale. (C) 1997 Optical Society of America. RP Krumbugel, MA (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,MS9057,LIVERMORE,CA 94551, USA. NR 14 TC 33 Z9 33 U1 2 U2 3 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 15 PY 1997 VL 22 IS 4 BP 245 EP 247 DI 10.1364/OL.22.000245 PG 3 WC Optics SC Optics GA WH246 UT WOS:A1997WH24600017 PM 18183164 ER PT J AU Kalyuzhnyi, YV Blum, L Holovko, MF Protsykevytch, IA AF Kalyuzhnyi, YV Blum, L Holovko, MF Protsykevytch, IA TI Primitive model for highly asymmetric electrolytes. Associative mean spherical approximation SO PHYSICA A LA English DT Article; Proceedings Paper CT Proceedings of the Workshop on Current Problems in Complex Fluids CY JAN 03-07, 1996 CL OAXACA, MEXICO DE highly asymmetric electrolytes; association; mean spherical approximation; primitive model; multidensity integral equation theory ID INTEGRAL-EQUATION THEORY; DIRECTIONAL ATTRACTIVE FORCES; HYPERNETTED-CHAIN APPROXIMATION; CHARGED COLLOIDAL DISPERSIONS; PERCUS-YEVICK APPROXIMATION; IONIC MICELLAR SOLUTIONS; STATISTICAL THERMODYNAMICS; POLY-ELECTROLYTES; PHASE-STABILITY; FLUID MIXTURES AB We study the primitive model of highly asymmetric electrolytes consisting of a mixture of m + n sticky charged hard spheres, where m of these components represent polyions and n represent counterions. It is assumed that the species representing polyions are highly charged and large in size, while the counterions are small in size and have at most two charges. A two-density version of the mean spherical approximation (associative MSA) explicitly accounting for the effects of the asymmetry is discussed and solved analytically. The approximation is based on the recently developed multidensity integral equation theory for highly asymmetric electrolyte solutions [Kalyuzhnyi et al., Chem. Phys. Lett. 215 (1993) 518; J. Chem. Phys. 102 (1995) 5770]. The analytic solution and the thermodynamic excess functions are given in terms of a single screening parameter Tr. The excess entropy has the same remarkably simple form Delta S-MSA = (Gamma(T))(3)/3 pi + sticky terms as found in previous work. C1 UNIV PUERTO RICO,DEPT PHYS,RIO PIEDRAS,PR 00931. NATL ACAD SCI,INST CONDENSED MATTER PHYS,UA-290011 LVIV,UKRAINE. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. NR 54 TC 21 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD FEB 15 PY 1997 VL 236 IS 1-2 BP 85 EP 96 DI 10.1016/S0378-4371(96)00404-9 PG 12 WC Physics, Multidisciplinary SC Physics GA WJ137 UT WOS:A1997WJ13700009 ER PT J AU Pietrass, T Bifone, A Kruger, J Reimer, JA AF Pietrass, T Bifone, A Kruger, J Reimer, JA TI Optically enhanced NMR of plastically deformed GaAs SO PHYSICAL REVIEW B LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; QUANTUM-WELLS AB Ga-69 and As-75 NMR of plastically deformed GaAs under optical pumping conditions at low temperatures is shown to exhibit substantial differences compared to results obtained from as-grown material. NMR signal enhancement has been observed in a wide energy range of the irradiation light above and below the band gap. The phase of the NMR signals is independent of the helicity of the pumping light. A continuum of intragap states introduced in the GaAs upon plastic deformation is involved in the polarization of the nuclei. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV MAT SCI, BERKELEY, CA 94720 USA. UNIV CALIF BERKELEY, DEPT CHEM ENGN, DEPT CHEM, BERKELEY, CA 94720 USA. NR 14 TC 7 Z9 7 U1 1 U2 3 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 15 PY 1997 VL 55 IS 7 BP 4050 EP 4053 DI 10.1103/PhysRevB.55.4050 PG 4 WC Physics, Condensed Matter SC Physics GA WK493 UT WOS:A1997WK49300013 ER PT J AU Rhee, JY Harmon, BN Lynch, DW AF Rhee, JY Harmon, BN Lynch, DW TI Optical properties and electronic structures of Ni3Al alloys SO PHYSICAL REVIEW B LA English DT Article ID FERMI-SURFACE; PHASE; MAGNETISM; NICKEL AB The dielectric functions of Ni,AI polycrystalline alloys were measured by spectroscopic ellipsometry in the energy range of 1.5-5.4 eV. The samples were Ni1-xAlx alloys with x = 0.2625,0.2525,0.25,0.244, and 0.2359. One broad peak was observed in the optical-conductivity spectra around 4.4eV. The band structures and the optical conductivity were calculated in the Au3Cu structure with the linearized-augmented-plane-wave method. By including both energy-dependent broadening and an approximate self-energy correction the calculated optical-conductivity spectrum gives quite good agreement with experiment. The calculation shows that the main contribution to the 4.4 eV peak comes from the k points close to the Gamma-M-R plane and near the midpoints of the X-M line and Gamma-M line. C1 IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. RP Rhee, JY (reprint author), HOSEO UNIV,COLL NAT SCI,DEPT PHYS,CHOONGNAM 336795,SOUTH KOREA. RI Rhee, Joo/D-2987-2011 NR 19 TC 38 Z9 39 U1 1 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 15 PY 1997 VL 55 IS 7 BP 4124 EP 4128 DI 10.1103/PhysRevB.55.4124 PG 5 WC Physics, Condensed Matter SC Physics GA WK493 UT WOS:A1997WK49300032 ER PT J AU Ahuja, R Auluck, S Wills, JM Alouani, M Johansson, B Eriksson, O AF Ahuja, R Auluck, S Wills, JM Alouani, M Johansson, B Eriksson, O TI Optical properties of graphite from first-principles calculations SO PHYSICAL REVIEW B LA English DT Article ID SINGLE-CRYSTAL GRAPHITE; ANGLE-RESOLVED PHOTOEMISSION; UNOCCUPIED ELECTRONIC STATES; BAND-STRUCTURE; INVERSE PHOTOEMISSION; SYNCHROTRON RADIATION; ELASTIC CONSTANTS; CONDUCTION-BAND; BRILLOUIN-ZONE; SPECIAL POINTS AB We present theoretical results for the frequency-dependent dielectric response, both for the electric field parallel and perpendicular to the c axis of graphite. The calculations are performed using a full-potential linear muffin-tin orbital method. Our calculations show fair agreement with experimental data and the different features observed are identified from interband transitions in various regions of the Brillouin zone. The anisotropy of the dielectric function is discussed in detail and shown to be due to the difference in the optical matrix elements for the two different polarizations, which is a result of the anisotropic crystallographic and electronic properties of graphite. C1 UNIV ROORKEE,DEPT PHYS,ROORKEE 247667,UTTAR PRADESH,INDIA. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87544. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. RP Ahuja, R (reprint author), UNIV UPPSALA,DEPT PHYS,CONDENSED MATTER THEORY GRP,BOX 530,S-75121 UPPSALA,SWEDEN. RI Alouani, Mebarek/A-9101-2011; Eriksson, Olle/E-3265-2014 OI Alouani, Mebarek/0000-0002-7985-5276; Eriksson, Olle/0000-0001-5111-1374 NR 46 TC 102 Z9 105 U1 5 U2 22 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 15 PY 1997 VL 55 IS 8 BP 4999 EP 5005 DI 10.1103/PhysRevB.55.4999 PG 7 WC Physics, Condensed Matter SC Physics GA WL499 UT WOS:A1997WL49900029 ER PT J AU Zhou, L Callcott, TA Jia, JJ Ederer, DL Perera, R AF Zhou, L Callcott, TA Jia, JJ Ederer, DL Perera, R TI Sulfur L(2,3) and zinc M(2,3) soft-x-ray fluorescence spectra in CdS and ZnS SO PHYSICAL REVIEW B LA English DT Article ID EXCITATION-ENERGY DEPENDENCE; PLANE-WAVE CALCULATIONS; IIB-VIA COMPOUNDS; ELECTRONIC-STRUCTURE; BAND-STRUCTURE; PHOTOELECTRON-SPECTROSCOPY; WURTZITE SEMICONDUCTORS; CHARGE-DENSITIES; CADMIUM-SULFIDE; EMISSION AB The sulfur L(2,3) Soft-x-ray emission spectra of wurtzite CdS and cubic ZnS and the zinc M(2,3) spectra of ZnS have been measured using both photon and electron-beam excitation. The photon-excited sulfur L spectra are found to be much sharper than electron-beam-excited spectra. Using photon excitation between the L(2) and L(3) thresholds, a pure L(3) spectrum-is obtained for both materials. Broad features of the S L spectra, consisting of a lower valence band (LVB) derived from the sulfur 3s orbital and an upper valence band (UVB)derived from S 3p and Cd(Zn) s and p orbitals, are typical of materials with mixed ionic-covalent character. A narrow band between the UVB and LVB is associated with overlap of Zn 3d and Cd 4d orbitals onto the S site. The s+d local partial density of states derived from these spectra provide a rigorous test of band-structure calculations; they are in good agreement for the position, width, and structure of the LVB and UVB, but place the d band deeper in the subband gap than theory predicts. The Zn M(2,3) spectrum has large lifetime broadening and thus provides limited information. However, near-threshold excitation of this spectrum shows dramatic effects resulting from an electronic resonance Raman process. C1 TULANE UNIV,NEW ORLEANS,LA 70118. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Zhou, L (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, USA. NR 62 TC 24 Z9 25 U1 0 U2 6 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 15 PY 1997 VL 55 IS 8 BP 5051 EP 5061 DI 10.1103/PhysRevB.55.5051 PG 11 WC Physics, Condensed Matter SC Physics GA WL499 UT WOS:A1997WL49900036 ER PT J AU Tian, Z DharmaWardana, MWC Lu, ZH Cao, R Lewis, LJ AF Tian, Z DharmaWardana, MWC Lu, ZH Cao, R Lewis, LJ TI Core-level spectroscopic study of the evolution of the sulfur-passivated InP(001) surface during annealing SO PHYSICAL REVIEW B LA English DT Article ID LARGE SYSTEMS; SI; PHOTOABSORPTION; DYNAMICS; SHIFTS; GAAS; INP AB Core-level photoemission spectroscopy and theoretical predictions of structure and spectra are used to study the fully S-covered InP(001) surface and its evolution during annealing. The theory predicts a number of stable structures besides the lowest-energy ground state which is the fully S-covered (2x2)-reconstructed structure, where the surface has two types of S atoms. On annealing, a fascinating sequence of structures unfolds from the fully S-covered ground state as the other stable structures become energetically accessible. The surface S atoms exchange with bulk P atoms on annealing, forming new strong S-P bonds while dissociating preexisting; S-S dimers. The S-P bonds are tilted with the P atoms just above the surface and there is only one type of S atom in the structure. The measured excitation energies and spectra agree with theoretical predictions of the core-level spectra for the (2x2) reconstruction and its evolution to partial S coverages. We conclude that the annealed surface around 700 K is most likely to be a (2x2) reconstructed surface with the surface cell containing two S-P bonds, with just one type of S atom. C1 NATL RES COUNCIL CANADA, INST MICROSTRUCT SCI, OTTAWA, ON K1A 0R6, CANADA. UNIV MONTREAL, DEPT PHYS, MONTREAL, PQ H3C 3J7, CANADA. UNIV MONTREAL, GRP RECH PHYS & TECHNOL COUCHES MINCES, GCM, MONTREAL, PQ H3C 3J7, CANADA. STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94309 USA. RI Lewis, Laurent/E-5546-2013 NR 38 TC 22 Z9 22 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2469-9950 EI 2469-9969 J9 PHYS REV B JI Phys. Rev. B PD FEB 15 PY 1997 VL 55 IS 8 BP 5376 EP 5383 DI 10.1103/PhysRevB.55.5376 PG 8 WC Physics, Condensed Matter SC Physics GA WL499 UT WOS:A1997WL49900076 ER PT J AU Menchero, JG AF Menchero, JG TI Theory of photoemission from the Ni 2p core level SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC LINEAR DICHROISM; X-RAY PHOTOEMISSION; FERROMAGNETIC NICKEL; SPIN POLARIZATION; CIRCULAR-DICHROISM; SPECTROSCOPY; METAL; IRON; SPECTRA; SYSTEMS AB Photoemission spectra are calculated for the Ni 2p core level within a small-cluster many-body scheme. The interplay between Coulomb, exchange, and spin-orbit interactions is discussed, as well as the role of extra-atomic screening. The spin-dependent transfer of spectral weight, both within and across the levels, is considered. Effects due to circular, linear, and unpolarized excitation are also examined. Local final-state configurations are reported, and a physical interpretation of the various spectral features is given. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Menchero, JG (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 34 TC 18 Z9 18 U1 1 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 15 PY 1997 VL 55 IS 8 BP 5505 EP 5516 DI 10.1103/PhysRevB.55.5505 PG 12 WC Physics, Condensed Matter SC Physics GA WL499 UT WOS:A1997WL49900090 ER PT J AU Kim, D Libon, IH Voelkmann, C Shen, YR PetrovaKoch, V AF Kim, D Libon, IH Voelkmann, C Shen, YR PetrovaKoch, V TI Multiphoton photoluminescence from GaN with tunable picosecond pulses SO PHYSICAL REVIEW B LA English DT Article ID NONDEGENERATE 2-PHOTON ABSORPTION; OPTICAL-PROPERTIES; THIN-FILMS; SEMICONDUCTORS; NITRIDE; ZNSE AB UV photoluminescence (PL) from GaN thin films was observed by multiphoton excitation. The two-photon PL excitation spectrum near the band gap agrees with the theoretical two-photon-absorption spectrum. The pump-intensity dependence and the PL excitation spectrum in the infrared indicate the existence of midgap defect states around 1 eV above the valence band. This is confirmed by the PL excitation spectrum obtained with a two-color, two-photon excitation process. RP Kim, D (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,DEPT PHYS,BERKELEY,CA 94720, USA. RI Kim, Doseok/J-8776-2013 NR 18 TC 32 Z9 32 U1 0 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 15 PY 1997 VL 55 IS 8 BP R4907 EP R4909 PG 3 WC Physics, Condensed Matter SC Physics GA WL499 UT WOS:A1997WL49900015 ER PT J AU Coble, K Dodelson, S Frieman, JA AF Coble, K Dodelson, S Frieman, JA TI Dynamical Lambda models of structure formation SO PHYSICAL REVIEW D LA English DT Article ID PARTICLE-PHYSICS MODELS; PSEUDO-GOLDSTONE BOSONS; LARGE-SCALE STRUCTURE; COLD DARK-MATTER; COSMOLOGICAL CONSTANT; MASS FLUCTUATIONS; CMB ANISOTROPIES; POWER SPECTRUM; UNIVERSE; CONSEQUENCES AB Models of structure formation with a cosmological constant Lambda provide a good fit to the observed power spectrum of galaxy clustering. However, they suffer from several problems. Theoretically, it is difficult to understand why the cosmological constant is so small in Planck units. Observationally, while the power spectra of cold dark matter plus Lambda models have approximately the right shape, the COBE-normalized amplitude for a scale-invariant spectrum is too high, requiring galaxies to be antibiased relative to the mass distribution. Attempts to address the first problem have led to models in which a dynamical field supplies the vacuum energy, which is thereby determined by fundamental physics scales. We explore the implications of such dynamical Lambda models for the formation of large-scale structure. We find that there are dynamical models for which the amplitude of the COPE-normalized spectrum matches the observations. We also calculate the cosmic microwave background anisotropies in these models and show that the angular power spectra are distinguishable from those of standard cosmological constant models. C1 FERMILAB NATL ACCELERATOR LAB,NASA,FERMILAB ASTROPHYS CTR,BATAVIA,IL 60510. RP Coble, K (reprint author), UNIV CHICAGO,DEPT ASTRON & ASTROPHYS,CHICAGO,IL 60637, USA. NR 52 TC 214 Z9 215 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 15 PY 1997 VL 55 IS 4 BP 1851 EP 1859 DI 10.1103/PhysRevD.55.1851 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK491 UT WOS:A1997WK49100017 ER PT J AU Rothman, T Anninos, P AF Rothman, T Anninos, P TI Phase space approach to the gravitational arrow of time SO PHYSICAL REVIEW D LA English DT Article ID ISOTROPIC SINGULARITIES; BLACK-HOLES; ENTROPY; FIELD AB As the universe evolves, it becomes more inhomogeneous due to gravitational clumping. We attempt to find a function that characterizes this behavior and increases monotonically as inhomogeneity increases. We choose S=ln Omega as the candidate ''gravitational entropy'' function, where Omega is the phase-space volume below the Hamiltonian H of the system under consideration. We perform a direct calculation of Omega for transverse electromagnetic waves and gravitational wave, radiation, and density perturbations in an expanding FLRW universe. These calculations are carried out in the linear regime under the assumption that the phases of the oscillators comprising the system are random. Entropy is thus attributed to the lack of knowledge of the exact field configuration. The time dependence of H leads to a time-dependent Omega. We find that Omega, and, hence, ln Omega behaves as required. We also carry out calculations for Bianchi type IX cosmological models and find that, even in this homogeneous case, the function can be interpreted sensibly. We compare our results with Penrose's C-2 hypothesis. Because S is defined to resemble the fundamental statistical mechanics definition of entropy, we are able to recover the entropy in a variety of familiar circumstances including, evidently, black-hole entropy. The results point to the utility of the relativistic Arnowitt-Deser-Misner (ADM) Hamiltonian formalism in establishing a connection between general relativity and statistical mechanics, although fully nonlinear calculations will need to be performed to remove any doubt. C1 PRINCETON UNIV,PLASMA PHYS LAB,PRINCETON,NJ 08543. UNIV ILLINOIS,NATL CTR SUPERCOMP APPLICAT,URBANA,IL 61801. NR 24 TC 9 Z9 9 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 15 PY 1997 VL 55 IS 4 BP 1948 EP 1963 DI 10.1103/PhysRevD.55.1948 PG 16 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK491 UT WOS:A1997WK49100026 ER PT J AU DelDebbio, L Faber, M Greensite, J Olejnik, S AF DelDebbio, L Faber, M Greensite, J Olejnik, S TI Center dominance and Z(2) vortices in SU(2) lattice gauge theory SO PHYSICAL REVIEW D LA English DT Article ID STOCHASTIC CONFINEMENT; DIMENSIONAL REDUCTION; ABELIAN DOMINANCE; COLOR CONFINEMENT; LARGE-N; MODEL; QCD AB We find, in close analogy to Abelian dominance in the maximal Abelian gauge, the phenomenon of center dominance in the maximal center gauge for SU(2) lattice gauge theory. The maximal center gauge is a gauge-fixing condition that preserves a residual Z(2) gauge symmetry; ''center projection'' is the projection of SU(2) link variables onto Z(2) center elements, and ''center dominance'' is the fact that;the center-projected link elements carry most of the information about the string tension of the full theory. We present numerical evidence that the thin Z(2) vortices Of the projected configurations are associated with ''thick'' Z(2) vortices in the unprojected configurations. The evidence also suggests that the thick Z(2) vortices may play a significant role in the confinement process. C1 VIENNA TECH UNIV,INST KERNPHYS,A-1040 VIENNA,AUSTRIA. SAN FRANCISCO STATE UNIV,DEPT PHYS & ASTRON,SAN FRANCISCO,CA 94132. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. SLOVAK ACAD SCI,INST PHYS,BRATISLAVA 84228,SLOVAKIA. RP DelDebbio, L (reprint author), UNIV COLL SWANSEA,DEPT PHYS,SWANSEA SA2 8PP,W GLAM,WALES. RI Olejnik, Stefan/C-6145-2008; OI Olejnik, Stefan/0000-0002-0910-7125; Del Debbio, Luigi/0000-0003-4246-3305; Greensite, Jeff/0000-0003-1720-9436 NR 23 TC 210 Z9 210 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 15 PY 1997 VL 55 IS 4 BP 2298 EP 2306 DI 10.1103/PhysRevD.55.2298 PG 9 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK491 UT WOS:A1997WK49100065 ER PT J AU Blankenbecler, R AF Blankenbecler, R TI Multiple scattering and functional integrals SO PHYSICAL REVIEW D LA English DT Article AB A functional integral method for performing the statistical averages implicit in problems involving multiple scattering is developed. The scattering fields in a noncrystalline medium are represented as a fixed set of fields for each incident particle, but are assumed to vary randomly from one particle in the beam to the next. The method is applied to eikonal treatments of both multiple scattering and photon radiation. This latter problem involves the Landau-Pomeranchuk-Migdal effect, and correction terms to earlier treatments are evaluated. RP Blankenbecler, R (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 14 TC 11 Z9 11 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD FEB 15 PY 1997 VL 55 IS 4 BP 2441 EP 2448 DI 10.1103/PhysRevD.55.2441 PG 8 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WK491 UT WOS:A1997WK49100079 ER PT J AU Gopal, M DeJonghe, LC Thomas, G AF Gopal, M DeJonghe, LC Thomas, G TI Silicon nitride joining using rare-earth reaction sintering SO SCRIPTA MATERIALIA LA English DT Article ID CERAMICS; BEHAVIOR C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,BERKELEY,CA 94720. RP Gopal, M (reprint author), UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94720, USA. NR 19 TC 16 Z9 18 U1 0 U2 0 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 15 PY 1997 VL 36 IS 4 BP 455 EP 460 DI 10.1016/S1359-6462(96)00392-2 PG 6 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA WF191 UT WOS:A1997WF19100014 ER PT J AU Jervis, TR Nastasi, M Griffin, AJ Zocco, TG Taylor, TN Foltyn, SR AF Jervis, TR Nastasi, M Griffin, AJ Zocco, TG Taylor, TN Foltyn, SR TI Tribological effects of excimer laser processing of tool steel SO SURFACE & COATINGS TECHNOLOGY LA English DT Article DE tribology; laser processing; mechanical properties; tool steel; surface treatment ID AISI-304 STAINLESS-STEEL; SURFACE MECHANICAL-PROPERTIES; TI; CERAMICS AB We examined the effects of excimer laser surface processing and of laser alloying with titanium on the mechanical and tribological properties of A-7 tool steel. We found that laser processing and alloying had no discernible effect on the mechanical properties of tempered steels. However, the dry, sliding friction coefficient of both laser processed and alloyed surfaces was reduced. Substantial but transient reductions in the friction are consistent with formation of a low friction transfer film. Long-lived reductions of friction in the laser processed case are associated with an absence of the adhesive wear which is conspicuous in the untreated case. RP Jervis, TR (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 25 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0257-8972 J9 SURF COAT TECH JI Surf. Coat. Technol. PD FEB 15 PY 1997 VL 89 IS 1-2 BP 158 EP 164 DI 10.1016/S0257-8972(96)03091-5 PG 7 WC Materials Science, Coatings & Films; Physics, Applied SC Materials Science; Physics GA WT613 UT WOS:A1997WT61300024 ER PT J AU Yu, ZG Rao, XS Sun, X Bishop, AR AF Yu, ZG Rao, XS Sun, X Bishop, AR TI The interchain coupling and exciton in conjugated polymers SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE many-body and quasiparticle theories; poly(phenylene vinylene) AB The exciton states in two coupled conjugated polymer chains are studied. These two chains are modeled individually by the Su-Schrieffer-Heeger Hamiltonian and coupled by an interchain electron-transfer term. Both the intra- and inter-chain long range Coulomb interactions are taken into account. It is found that, for parallel and anti-parallel orderings, the features of excitons are quite different. Possible implications for the experiment of luminescent polymers are also addressed. C1 FUDAN UNIV,TD LEE LAB,DEPT PHYS,SHANGHAI 200433,PEOPLES R CHINA. NATL LAB INFRARED PHYS,SHANGHAI 200083,PEOPLES R CHINA. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. NR 8 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1135 EP 1136 DI 10.1016/S0379-6779(97)80182-8 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800053 ER PT J AU Wei, X Jeglinski, SA Vardeny, ZV AF Wei, X Jeglinski, SA Vardeny, ZV TI Photoresponse and electroresponse studies of polymer light-emitting diodes SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE electroluminescence; photoconductivity; poly(phenylene vinylene) and derivatives ID POLY(PARA-PHENYLENEVINYLENE); EMISSION AB We have developed and applied a non-destructive and non-invasive technique, the saturated photovoltage (SPV), to measure the internal built-in potential, V-bi, in conducting polymer based light-emitting diodes (LED). We found that V-bi scales with the difference in work function between the two capping metal electrodes in a variety of polymer LEDs, independent of the constituent polymer. The SPV technique can be used as a diagnostic tool to study the polymer device quality and degradation. In addition, the photocurrent excitation spectra of polymer LEDs are shown to be sensitive to states in the gap and also to spectral features above the optical gap. C1 UNIV UTAH,DEPT PHYS,SALT LAKE CITY,UT 84112. RP Wei, X (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 17 TC 12 Z9 12 U1 1 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1215 EP 1218 DI 10.1016/S0379-6779(97)80212-3 PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800083 ER PT J AU Schlueter, JA Geiser, U Williams, JM Dudek, JD Kelly, ME Flynn, JP Wilson, RR Zakowicz, HI Sche, PP Naumann, D Roy, T Nixon, PG Winter, RW Gard, GL AF Schlueter, JA Geiser, U Williams, JM Dudek, JD Kelly, ME Flynn, JP Wilson, RR Zakowicz, HI Sche, PP Naumann, D Roy, T Nixon, PG Winter, RW Gard, GL TI Rational design of organic superconductors through the use of the large, discrete molecular anions M(CF3)(4)(-) (M=Cu, Ag, Au) and SO3CF2CH2SF5- SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE electrocrystallization; organic superconductors ID AMBIENT-PRESSURE SUPERCONDUCTIVITY; ELECTRON-DONOR MOLECULE; CONDUCTIVITY; (TMTSF)2CLO4; PERCHLORATE; TEMPERATURE; DISORDER; SYSTEM; TC AB A new approach to the synthesis of organic superconductors has recently been pioneered which involves the use of large, discrete, molecular anions as the charge-compensating entities in these charge transfer salts. The organic electron-donor molecule bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF or ET) has been electrocrystallized with the novel organometallic M(CF3)(4)(-) (M = Cu, Ag, and Au) anions in a variety of 1,1,2-trihaloethane solvents. Over twenty organic superconductors have been synthesized which can be described by the general formula (ET)(2)M(CF3)(4)(1,1,2-trihaloethane). These solvated salts are shown to have highly anisotropic physical properties which can be tuned via modifications of each of their three molecular components: ET electron donor molecule, M(CF3)(4)(-) anion, and neutral 1,1,2-trihaloethane solvent molecule. Superconductivity has also been observed in an ET salt containing the discrete SF5CH2CF2SO3- anion with an onset temperature near 5.2 K. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. UNIV COLOGNE,INST ANORGAN CHEM,D-50939 COLOGNE,GERMANY. PORTLAND STATE UNIV,DEPT CHEM,PORTLAND,OR 97207. RP Schlueter, JA (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 18 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1453 EP 1456 DI 10.1016/S0379-6779(97)80313-X PG 4 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800184 ER PT J AU Geiser, U Schlueter, JA Williams, JM Kini, AM Dudek, JD Kelly, ME Naumann, D Roy, T AF Geiser, U Schlueter, JA Williams, JM Kini, AM Dudek, JD Kelly, ME Naumann, D Roy, T TI Polymorphism in kappa-(BEDT-TTF)(2)M(CF3)(4)(solvent) superconductors SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE organic superconductors; X-ray diffraction ID ORGANIC SUPERCONDUCTORS; ANION AB A new crystallographic modification (kappa(L)') was found in the BEDT-TTF:M(CF3)(4)(-):solvent (M = Cu, Ag, Au) system. The structure of monoclinic kappa(L)'-(BEDT-TTF)(2)Cu(CF3)(4)(1,2-dibromo-1-chloroethane = DBCE) is reported. It differs from the orthorhombic kappa(L)-phase by having all BEDT-TTF molecules tilted in the same direction with respect to the conducting plane normal, whereas in kappa(L) the tilt direction alternates between layers. C1 UNIV COLOGNE,INST ANORGAN CHEM,D-50939 COLOGNE,GERMANY. RP Geiser, U (reprint author), ARGONNE NATL LAB,DIV CHEM & MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Kini, Aravinda/F-4467-2012 NR 6 TC 6 Z9 6 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1465 EP 1466 DI 10.1016/S0379-6779(97)80318-9 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800189 ER PT J AU Dressel, M Gruner, G Eldridge, JE Williams, JM AF Dressel, M Gruner, G Eldridge, JE Williams, JM TI Optical properties of organic superconductors SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE reflection spectroscopy; transport measurements; superconducting phase transition; organic superconductors ID MAGNETIC PENETRATION DEPTH; KAPPA-(ET)2X SUPERCONDUCTORS; ELECTRICAL-RESISTIVITY; ISOTOPIC-SUBSTITUTION; INFRARED PROPERTIES; SPIN-RELAXATION; BEDT-TTF; BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE; STATE; CONDUCTORS AB Optical studies, in a wide sense, are one of the most powerful techniques for studying the electronic properties of solids. We discuss investigations of the electrodynamic response in the two-dimensional organic conductors of the BEDT-TTF family, which become superconducting at around 10 K. in the normal state, the frequency dependent conductivity is that of a correlated metal with significant deviations from the simple Drude model. The electrodynamical properties of the superconducting state are those of an anisotropic BCS superconductor with no indications of unconventional pairing. C1 UNIV CALIF LOS ANGELES,DEPT PHYS,LOS ANGELES,CA 90024. UNIV BRITISH COLUMBIA,DEPT PHYS,VANCOUVER,BC V6T 1Z1,CANADA. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60349. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60349. RP Dressel, M (reprint author), TH DARMSTADT,INST FESTKORPERPHYS,D-64289 DARMSTADT,GERMANY. RI Dressel, Martin/D-3244-2012 NR 49 TC 13 Z9 13 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1503 EP 1508 DI 10.1016/S0379-6779(97)80325-6 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800200 ER PT J AU Pedron, D Visentini, G Cecchetto, E Bozio, R Williams, JM Schlueter, JA AF Pedron, D Visentini, G Cecchetto, E Bozio, R Williams, JM Schlueter, JA TI Raman spectroscopy of low frequency phonons in the organic superconductor kappa-(BEDT-TTF)(2)Cu[N(CN)(2)]Br SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE organic superconductors; infrared and Raman spectroscopy; superconducting phase transitions ID HIGH-TC SUPERCONDUCTORS; KAPPA-(BEDT-TTF)2CUBR; SCATTERING AB The low frequency Raman spectra of kappa-(BEDT-TIF)(2)Cu[N(CN)(2)]Br have been studied in the temperature range 1.8 - 125 K and effects associated with the opening of the superconducting gap have been identified. They indicate an upper limit of ca. 28 cm(-1) for the superconducting gap and appear to be more consistent with an s-wave than with a d-wave structure of the gap. C1 ARGONNE NATL LAB,DIV CHEM & MAT SCI,ARGONNE,IL 60439. RP Pedron, D (reprint author), UNIV PADUA,DEPT PHYS CHEM,VIA LOREDAN 2,I-35131 PADUA,ITALY. RI Bozio, Renato/E-9066-2012 OI Bozio, Renato/0000-0001-7274-9190 NR 14 TC 6 Z9 6 U1 1 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1509 EP 1510 DI 10.1016/S0379-6779(97)80326-8 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800201 ER PT J AU Wang, HH VanZile, ML Geiser, U Schlueter, JA Williams, JM Kini, AM Sche, PP Nixon, PG Winter, RW Gard, GL Naumann, D Roy, T AF Wang, HH VanZile, ML Geiser, U Schlueter, JA Williams, JM Kini, AM Sche, PP Nixon, PG Winter, RW Gard, GL Naumann, D Roy, T TI ESR studies of two new organic superconductors: beta''-(BEDT-TTF)(2)SF5CH2CF2SO3 and K-L'-(BEDT-TTF)(2)Cu(CF3)(4)(DBCE) SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE organic superconductors; ESR; line width; g-value; microwave conductivity AB The normal-state ESR properties of two new organic superconductors, beta''-(BEDT-TTF)(2)SF5CH2CF2SO3 and K-L'-(BEDT-TTF)(2)Cu(CF3)(4)(DBCE) are reported. Both compounds showed metallic properties below 140 K. The former gave ESR line widths and g-values of 23 to 34 G and 2.004 to 2.012, respectively. The latter gave line widths and g-values of 45 to 58 G and 2.006 to 2.012, respectively. The orientation-dependent line widths and g-values of the K-L'-phase were found to be similar to that of the kappa-(ET)(4)Hg3Br8 but not to the K-L-phases in general. C1 ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. PORTLAND STATE UNIV,DEPT CHEM,PORTLAND,OR 97207. UNIV COLOGNE,INST ANORGAN CHEM,D-50939 COLOGNE,GERMANY. RP Wang, HH (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Kini, Aravinda/F-4467-2012 NR 6 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1533 EP 1534 PG 2 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800210 ER PT J AU Kini, AM Carlson, KD Dudek, JD Geiser, U Wang, HH Williams, JM AF Kini, AM Carlson, KD Dudek, JD Geiser, U Wang, HH Williams, JM TI Isotope effect in BEDT-TTF based organic superconductors SO SYNTHETIC METALS LA English DT Article; Proceedings Paper CT International Conference on the Science and Technology of Synthetic Metals CY JUL 28-AUG 02, 1996 CL SNOWBIRD, UT SP Univ Utah, Elsevier Sci SA, Los Alamos Nat Lab, Monsanto, Off Naval Res, US Dept Energy, Bayer Corp, Taiwan United Microelec Corp, Uniax DE organic superconductors; BEDT-TTF or ET; isotope effect on T-c; magnetic measurements; BCS theory ID KAPPA-(ET)2X SUPERCONDUCTORS; AMBIENT PRESSURE; SUBSTITUTION; BIS(ETHYLENEDITHIO)TETRATHIAFULVALENE; MECHANISM; ATOMS AB The results of our comprehensive isotope effect studies, in which seven different isotopically labeled (involving C-13, S-34 and H-2 labeling) BEDT-TTF derivatives and isotopically labeled anion [Cu((NCS)-N-15-C-13)(2)](-) were utilized, are summarized. For the first time, convincing evidence for a genuine BCS-like mass isotope effect in an organic superconductor is revealed in our studies. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Kini, AM (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Kini, Aravinda/F-4467-2012 NR 27 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0379-6779 J9 SYNTHETIC MET JI Synth. Met. PD FEB 15 PY 1997 VL 85 IS 1-3 BP 1617 EP 1622 DI 10.1016/S0379-6779(97)80373-6 PG 6 WC Materials Science, Multidisciplinary; Physics, Condensed Matter; Polymer Science SC Materials Science; Physics; Polymer Science GA WX708 UT WOS:A1997WX70800248 ER PT J AU Neufeld, E Wang, S Apetz, R Buchal, C Carius, R White, CW Thomas, DK AF Neufeld, E Wang, S Apetz, R Buchal, C Carius, R White, CW Thomas, DK TI Effect of annealing and H-2 passivation on the photoluminescence of Si nanocrystals in SiO2 SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT European-Materials-Research-Society 1996 Spring Meeting, Symposium D: Group IV Heterostructures, Physics and Devices CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc DE photoluminescence; silicon ID QUANTUM CONFINEMENT; GE NANOCRYSTALS; SILICON; MATRICES AB Silicon nanocrystals have been synthesized in an SiO2 matrix using Si ion implantation. Si implantations have been performed at 35 keV with doses from I x 10(16) cm(-2) to 7 x 10(16) cm(-2), corresponding to peak excess concentrations of 3 at.% to 17 at.%. The samples have been annealed in vacuum at various temperatures to obtain Si nanoclusters of different sizes. Photoluminescence (PL) experiments show a distinct shift of the spectra towards lower energies and a decrease in intensity with increasing a annealing temperature between 700 degrees C and 900 degrees C for doses higher than 5 x 10(16) cm(-2). We also observe for these samples that the peak position appears at lower energy for higher doses, Additional annealing in H-2/N-2 results in a strong increase of the PL intensity which is attributed to the passivation of defects. Annealing the samples again in vacuum leads to a reproduction of the former PL spectra showing the reversibility of the passivation, These experiments are in qualitative agreement with the quantum confinement model and in contradiction to recent observations made on Ge nanocrystals in a SiO2 matrix (K.S. Min et al., Appl. Phys. Lett., submitted). C1 FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST SCHICHT & IONENTECH, D-52425 JULICH, GERMANY. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. NR 11 TC 41 Z9 42 U1 1 U2 1 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB 15 PY 1997 VL 294 IS 1-2 BP 238 EP 241 DI 10.1016/S0040-6090(96)09265-6 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA WX962 UT WOS:A1997WX96200057 ER PT J AU Chen, SI Sheu, YL Sheu, JL Lee, CT Lin, JS AF Chen, SI Sheu, YL Sheu, JL Lee, CT Lin, JS TI Morphology of perfluoroalkylacrylate/stearyl methacrylate polymers and their effect on water/oil repellency SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article DE oil repellency; small angle x-ray scattering ID X-RAY-SCATTERING; PERCUS-YEVICK FLUID; DISTRIBUTED DIAMETERS; POLYDISPERSITY; SYSTEM AB The small-angle X-ray scattering technique was applied to study the morphology of a series of water-repellent terpolymers polymerized from a fluoro-component, a hydrocarbon-component and a crosslinking agent. The intraparticle homogeneity of the terpolymers was semiquantitatively determined from the small-angle X-ray spectra using a proposed structural model. The X-ray results were correlated to the water repellency test data using the AATCC test method 22-1989. The consistency of the polymerization reaction process as a function of the weight ratio of the fluoro-components is discussed. (C) 1997 John Wiley & Sons, Inc. C1 VANTON RES LAB INC,HOPEWELL JCT,NY 12533. IND TECHNOL RES INST,UNION CHEM LAB,HSINCHU 300,TAIWAN. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NR 18 TC 21 Z9 27 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0021-8995 J9 J APPL POLYM SCI JI J. Appl. Polym. Sci. PD FEB 14 PY 1997 VL 63 IS 7 BP 903 EP 909 DI 10.1002/(SICI)1097-4628(19970214)63:7<903::AID-APP10>3.0.CO;2-S PG 7 WC Polymer Science SC Polymer Science GA WC957 UT WOS:A1997WC95700010 ER PT J AU Wu, LNY Genge, BR Dunkelberger, DG LeGeros, RZ Concannon, B Wuthier, RE AF Wu, LNY Genge, BR Dunkelberger, DG LeGeros, RZ Concannon, B Wuthier, RE TI Physicochemical characterization of the nucleational core of matrix vesicles SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID GROWTH-PLATE CARTILAGE; EPIPHYSEAL CARTILAGE; CALCIUM PHOSPHATES; ALKALINE-PHOSPHATASE; MINERAL PHASES; BONE; CALCIFICATION; SPECTROSCOPY; MEMBRANE; COMPLEX AB While previous studies revealed that matrix vesicles (MV) contain a nucleational core (NC) that converts to apatite when incubated with synthetic cartilage lymph, the initial mineral phase present in MV is not well characterized. This study explored the physicochemical nature of this Ca2+ and P-i-rich NC. MV, isolated from growth plate cartilage, were analyzed directly by solid-state P-31 NMR, or incubated with hydrazine or NaOCl to remove organic constituents. Other samples of MV were subjected to sequential treatments with enzymes, salt solutions, and detergents to expose the NC. We examined the NC using transmission electron microscopy, energy-dispersive analysis with x-rays, and electron and x-ray diffraction, Fourier transform-infrared spectroscopy, high performance thin-layer chromatographic analysis, and SDS-polyacrylamide gel electrophoresis, We found that most of the MV proteins and lipids could be removed without destroying the NC; however, NaOCl treatment annihilated its activity. SDS-polyacrylamide gel electrophoresis showed that annexin V, a phosphatidylserine (PS)-dependent Ca2+-binding protein, was the major protein in the NC; high performance thin-layer chromatographic analysis revealed that the detergents removed the majority of the polar lipids, but left significant free cholesterol and fatty acids, and small but critical amounts of PS. Transmission electron microscopy showed that the NC was composed of clusters of similar to 1.0 nm subunits, which energy-dispersive analysis with x-rays revealed contained Ca and P-i with a Ca/P ratio of 1.06 +/- 0.01, Electron diffraction, x-ray diffraction, and Fourier transform-infrared analysis all indicated that the NC was noncrystalline. H-1-Cross-polarization P-31 MMR indicated that the solid phase of MV was an HPO42--rich mixture of amorphous calcium phosphate and a complex of PS, Ca2+, and P-i, Taken together, our findings indicate that the NC of MV is composed of an acid-phosphate-rich amorphous calcium phosphate intermixed with PS-Ca2+-P-i, annexin V, and other proteins and lipids. C1 UNIV S CAROLINA, PHYS SCI CTR 424A, DEPT CHEM & BIOCHEM, LAB BIOMINERALIZAT RES, COLUMBIA, SC 29208 USA. UNIV S CAROLINA, SCH MED, COLUMBIA, SC 29208 USA. UNIV S CAROLINA, COLL SCI & MATH, CTR ELECTRON MICROSCOPY, COLUMBIA, SC 29208 USA. NYU, COLL DENT, CALCIUM PHOSPHATE RES LAB, NEW YORK, NY 10010 USA. PACIFIC NW LAB, ENVIRONM & MOL SCI LAB, RICHLAND, WA 99352 USA. FU NIAMS NIH HHS [AR18983] NR 56 TC 81 Z9 84 U1 0 U2 13 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 FEB 14 PY 1997 VL 272 IS 7 BP 4404 EP 4411 PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WH019 UT WOS:A1997WH01900079 PM 9020163 ER PT J AU Stanley, BJ Foster, CR Guiochon, G AF Stanley, BJ Foster, CR Guiochon, G TI On the reproducibility of column performance in liquid chromatography and the role of the packing density SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE stationary phases, LC; packing density; column efficiency; retention factors; preparative chromatography ID EFFICIENCY AB The packing behavior of a typical 10 mu m C-18 stationary phase was studied in terms of the resultant column efficiency and capacity factor. The column-to-column reproducibility of these parameters under identical packing procedures is assessed. Correlation of these parameters and the column void volume to the column packing density is reported. Two regimes were studied; that of poor-and well-packed columns. For poorly packed columns, the column-to-column variability is high, but a concomitantly poor same-column reproducibility of measurement suggests that little statistically significant difference exists between different columns packed with the same procedure. There is also no statistically significant correlation between the column parameters and the packing densities, however, the poorest columns skewed a degradation of performance after the drying procedures used to obtain the column masses. Well-packed columns showed much less degradation upon drying. For the well-packed columns, statistically significant column-to-column differences were observable, mainly due to a high same-column precision of measurement. Analysis of the results suggests that even well-packed columns are not optimally packed and that regions of high and low density coexist along the column. The results are compared to those achieved with semi-preparative columns packed with the same slurry procedure and preparative columns packed under dynamic axial compression. Poor day to-day, same-column reproducibility (degradation) under ambient conditions was observed in conjunction with a high column-to-column variability for the semi-preparative columns. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. CALIF STATE COLL SAN BERNARDINO,DEPT CHEM,SAN BERNARDINO,CA 92507. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. NR 15 TC 25 Z9 25 U1 0 U2 5 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 FEB 14 PY 1997 VL 761 IS 1-2 BP 41 EP 51 DI 10.1016/S0021-9673(96)00804-7 PG 11 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA WM846 UT WOS:A1997WM84600006 ER PT J AU Dunford, RW AF Dunford, RW TI Orientation of 1s electrons using tilted foils SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID SPIN-POLARIZED ELECTRONS; HIGHLY CHARGED IONS; NUCLEAR-POLARIZATION; HYPERFINE INTERACTIONS; SURFACE-INTERACTION; ATOMIC-BEAMS; ALIGNMENT; EXCITATION; CAPTURE; STATES AB The prospects for producing orientation of the is level in highly charged ions using tilted foils is discussed. We analyse the transfer of orientation from the initial orbital angular momentum of an ion emerging from a foil to the ground-state spin via a combination of the spin-orbit interaction and cascade decays. An enhancement of the orientation can be obtained using a multi-tilted-foil technique similar to that used to orient nuclei. RP Dunford, RW (reprint author), ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439, USA. NR 63 TC 1 Z9 1 U1 0 U2 1 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 14 PY 1997 VL 30 IS 3 BP 523 EP 533 DI 10.1088/0953-4075/30/3/009 PG 11 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WK004 UT WOS:A1997WK00400009 ER PT J AU Berkowitz, J AF Berkowitz, J TI Absolute photoionization cross sections of atomic oxygen SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID PHOTOIONISATION; TRANSITIONS; STATES AB Conflicting calibrations of the absolute photoionization cross sections of atomic oxygen in the vacuum and extreme ultraviolet are tested by a sum-rule analysis. It is shown that the scaling factor obtained by Samson and Pareek results in much closer adherence to three sum rules. RP Berkowitz, J (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 36 TC 10 Z9 10 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 14 PY 1997 VL 30 IS 3 BP 583 EP 592 DI 10.1088/0953-4075/30/3/014 PG 10 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WK004 UT WOS:A1997WK00400014 ER PT J AU Langer, B Berrah, N Wehlitz, R Gorczyca, TW Bozek, J Farhat, A AF Langer, B Berrah, N Wehlitz, R Gorczyca, TW Bozek, J Farhat, A TI Angular distribution of the Ne 2s->np autoionization resonances: Experimental and theoretical study SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID CROSS-SECTIONS; PHOTOIONIZATION; REDETERMINATION; PHOTOELECTRONS; EXCITATION; STRENGTHS; THRESHOLD; ATOMS AB We have used angle-resolved photoelectron spectroscopy and improved R-matrix calculations to study the Ne 2s(2)2p(6) --> 2s2p(6)np (n = 3-5) autoionizing resonances and the 2s(2)2p(6) --> 2P(4)(P-3)3s(P-2)3P P-1(1) doubly excited resonance in the photon energy range between 44 and 48.5 eV. The photoelectrons were detected at different angles using three time-of-flight spectrometers. The measurements were obtained utilizing the 18 meV photon energy resolution provided by an undulator coupled with a spherical grating monochromator of the Advanced Light Source. Angular distribution parameters beta of these resonances have been parametrized using a model by Kabachnik and Sazhina and have been compared with our R-matrix calculations which are similar to those of Burke and Taylor. We find that the calculations agree quite well with the measurements. Our analysis of the cross section shape shows no strong n dependence of the q and rho parameter, while the width Gamma varies as the quantum defect theory predicts. Also, the differential cross section parameters agree well with previous experiments carried out for the lower resonances. C1 UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 94720. RP Langer, B (reprint author), WESTERN MICHIGAN UNIV,DEPT PHYS,KALAMAZOO,MI 49008, USA. RI Bozek, John/E-4689-2010; Langer, Burkhard/A-6504-2013; Bozek, John/E-9260-2010 OI Bozek, John/0000-0001-7486-7238 NR 30 TC 9 Z9 9 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD FEB 14 PY 1997 VL 30 IS 3 BP 593 EP 607 DI 10.1088/0953-4075/30/3/015 PG 15 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA WK004 UT WOS:A1997WK00400015 ER PT J AU Quigg, C AF Quigg, C TI The quantum theory of fields .2. Modern applications - Weinberg,S SO SCIENCE LA English DT Book Review RP Quigg, C (reprint author), FERMILAB NATL ACCELERATOR LAB,DEPT THEORET PHYS,POB 500,BATAVIA,IL 60510, USA. NR 1 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 FEB 14 PY 1997 VL 275 IS 5302 BP 938 EP 939 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WH388 UT WOS:A1997WH38800030 ER PT J AU Cooper, PK Nouspikel, T Clarkson, SG Leadon, SA AF Cooper, PK Nouspikel, T Clarkson, SG Leadon, SA TI Defective transcription-coupled repair of oxidative base damage in Cockayne syndrome patients from XP group G (Retracted Article. See vol 308, pg 1740, 2005) SO SCIENCE LA English DT Article; Retracted Publication ID PIGMENTOSUM GROUP-G; NUCLEOTIDE EXCISION-REPAIR; COMPLEMENTATION GROUP-G; RNA-POLYMERASE-II; DNA-REPAIR; IONIZING-RADIATION; PREFERENTIAL REPAIR; THYMINE GLYCOLS; ACTIVE GENES; YEAST RAD2 AB In normal human cells, damage due to ultraviolet light is preferentially removed from active genes by nucleotide excision repair (NER) in a transcription-coupled repair (TCR) process that requires the gene products defective in Cockayne syndrome (CS). Oxidative damage, including thymine glycols, is shown to be removed by TCR in cells from normal individuals and from xeroderma pigmentosum (XP)-A, XP-F, and XP-G patients who have NER defects but not from XP-G patients who have severe CS. Thus, TCR of oxidative damage requires an XPG function distinct from its NER endonuclease activity. These results raise the possibility that defective TCR of oxidative damage contributes to the developmental defects associated with CS. C1 UNIV GENEVA, MED CTR, DEPT GENET & MICROBIOL, CH-1211 GENEVA 4, SWITZERLAND. UNIV N CAROLINA, SCH MED, DEPT RADIAT ONCOL, CHAPEL HILL, NC 27599 USA. RP Cooper, PK (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY NATL LAB, DIV LIFE SCI, BLDG 934, 1 CYCLOTRON RD, BERKELEY, CA 94720 USA. FU NCI NIH HHS [CA40453, CA63503] NR 46 TC 268 Z9 268 U1 5 U2 9 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 FEB 14 PY 1997 VL 275 IS 5302 BP 990 EP 993 DI 10.1126/science.275.5302.990 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WH388 UT WOS:A1997WH38800049 PM 9020084 ER PT J AU Owens, TG Lee, JW Tevault, CV Greenbaum, E AF Owens, TG Lee, JW Tevault, CV Greenbaum, E TI Oxygenic photoautotrophic growth and photosystem I SO SCIENCE LA English DT Article C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Owens, TG (reprint author), CORNELL UNIV,PLANT BIOL SECT,ITHACA,NY 14853, USA. NR 1 TC 1 Z9 1 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 FEB 14 PY 1997 VL 275 IS 5302 BP 996 EP 996 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WH388 UT WOS:A1997WH38800052 ER PT J AU Lehman, JA Morgan, RA Carlson, D Crawford, MH Choquette, KD AF Lehman, JA Morgan, RA Carlson, D Crawford, MH Choquette, KD TI High-frequency modulation characteristics of red VCSELs SO ELECTRONICS LETTERS LA English DT Article DE vertical cavity surface emitting lasers; modulation; visible semiconductor lasers AB The authors have measured small- and large-signal modulation response characteristics of a red VCSEL (lambda = 670nm). A small-signal 3dB bandwidth of 11 GHz was recorded at a bias current of 16mA. The small-signal response for each bias current was fit to an analytic model to determine the resonance and damping factor. From these data the differential gain coefficient and K-factor were estimated. Large signal digital measurements were conducted showing suitability of this device for data communication applications. An open eye diagram at the receiver output is presented with no pre-bias current applied and the VCSEL modulated at 155Mbit/s demonstrating the possibility of direct logic-level drive. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Lehman, JA (reprint author), HONEYWELL TECHNOL CTR,3660 TECHNOL DR,MINNEAPOLIS,MN 55418, USA. NR 6 TC 20 Z9 20 U1 1 U2 6 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 FEB 13 PY 1997 VL 33 IS 4 BP 298 EP 300 DI 10.1049/el:19970179 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA WT997 UT WOS:A1997WT99700032 ER PT J AU Mayer, PM Keister, JW Baer, T Evans, M Ng, CY Hsu, CW AF Mayer, PM Keister, JW Baer, T Evans, M Ng, CY Hsu, CW TI The dimethylamine dimer ion is an ion-radical complex: A combined TPEPICO, variational RRKM, and ab initio MO study of the fragmentation of ionized dimers of dimethylamine SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TRANSITION-STATE THEORY; ADVANCED LIGHT-SOURCE; CHEMICAL-DYNAMICS; DISSOCIATION; PHOTOIONIZATION; CLUSTERS; BEAMLINE; ENERGIES; PHASE AB Threshold photoelectron photoion coincidence spectroscopy has been used to study the fragmentation mechanism of dimethylamine dimer ions. The fragmentation rate constant data obtained from the experiment were modeled with variational RRKM theory using potential energies and vibrational frequencies from ab initio molecular orbital calculations at the MP2/6-31G* level. The results are consistent with the fragmentation of the dimethylamine dimer ion into protonated dimethylamine and the (CH2N)-C-.(H)CH3 radical. This was supported by ab initio calculations in which the dimer ion was found to consist of a N-H-C hydrogen-bonded complex between the above two products. The RRKM fit to the experimental k(E) vs E data for the ion gave a dimethylamine dimer ion Delta(f)H(0)(o) of 653 +/- 11 kT mol(-1) and thus a dimer ion binding energy of 147 +/- 16 kJ mol(-1). In agreement with recent experimental results, the neutral dimethylamine dimer was calculated to be an N-H-N hydrogen-bonded dimer with a 0 K binding energy of 13 +/- 3 kJ mol(-1). The resulting neutral dimer adiabatic ionization energy is 6.8 +/- 0.2 eV. C1 UNIV N CAROLINA,DEPT CHEM,CHAPEL HILL,NC 27599. IOWA STATE UNIV SCI & TECHNOL,US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,US DOE,DEPT CHEM,AMES,IA 50011. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 30 TC 8 Z9 8 U1 0 U2 0 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 FEB 13 PY 1997 VL 101 IS 7 BP 1270 EP 1276 DI 10.1021/jp9627077 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL092 UT WOS:A1997WL09200013 ER PT J AU Mezyk, SP Bartels, DM AF Mezyk, SP Bartels, DM TI Rate of hydrogen atom reaction with ethanol, ethanol-d(5), 2-propanol, and 2-propanol-d(7) in aqueous solution SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID EPR MEASUREMENT; ARRHENIUS PARAMETERS; HYDRATED ELECTRONS; WATER RADIOLYSIS; BENZENE AB Arrhenius parameters for the reaction of hydrogen atoms with ethanol, ethanol-d(5), 2-propanol, and 2-propanol d(7) in aqueous solution have been determined by the use of pulse radiolysis and electron paramagnetic resonance free induction decay attenuation measurements. At 25.0 degrees C, the calculated rate constants for these compounds are (2.04 +/- 0.06) x 10(7), (2.77 +/- 0.26) x 10(6), (1.01 +/- 0.07) x 10(8), and (1.56 +/- 0.07) x 10(7) dm(3) mol(-1) s(-1) respectively, with corresponding activation energies of 24.10 +/- 0.50 (6.5-81.3 degrees C), 31.9 +/- 1.2 (22.4-79.6 degrees C), 22.00 +/- 0.26 (5.4-88.5 degrees C), and 27.45 +/- 0.30 (5.7-86.5 degrees C) kJ mol(-1). The results of this study are compared to previous reports and ab initio calculations. C1 ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. RP Mezyk, SP (reprint author), ATOM ENERGY CANADA LTD,WHITESHELL LABS,RES CHEM BRANCH,PINAWA,MB R0E 1L0,CANADA. NR 40 TC 25 Z9 25 U1 0 U2 9 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 FEB 13 PY 1997 VL 101 IS 7 BP 1329 EP 1333 DI 10.1021/jp9629957 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL092 UT WOS:A1997WL09200022 ER PT J AU Gentemann, S Nelson, NY Jaquinod, L Nurco, DJ Leung, SH Medforth, CJ Smith, KM Fajer, J Holten, D AF Gentemann, S Nelson, NY Jaquinod, L Nurco, DJ Leung, SH Medforth, CJ Smith, KM Fajer, J Holten, D TI Variations and temperature dependence of the excited state properties of conformationally and electronically perturbed zinc and free base porphyrins SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NONPLANAR NICKEL(II) PORPHYRINS; PHOTOSYNTHETIC REACTION-CENTER; SUBSTITUTED PORPHYRINS; BACTERIOCHLOROPHYLL-A; RESOLUTION; DISTORTION; DEACTIVATION; FLUORESCENCE; PROTEIN; SOLVENT AB The photophysical properties and their temperature dependence are reported for the sterically encumbered nonplanar zinc and free base 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrins (ZnDPP and H2DPP), and 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrins (ZnOETPP and H(2)OETPP), and the zinc complex of 5,10,15,20-tetra-tert-butylporphyrin (ZnT(t-Bu)P). Compared to planar 5,10,15,20-tetraphenylporphyrins (ZnTPP and H2TPP), the above compounds exhibit reduced lifetimes of the lowest excited singlet state, reduced fluorescence yields, and large shifts between their absorption and emission maxima at room temperature. ZnT(t-Bu)P, which is known to adopt a ruffled conformation, displays dramatically altered photophysical properties including a 7 ps (1)(pi,pi(*)) lifetime compared to one of similar to 2 ns for ZnTPP at 296 K. Equally noteworthy is the return of the ZnT(t-Bu)P singlet lifetime to a ''normal'' value of 2.5 ns at 78 K. An analogous temperature dependence has been observed previously for the free base analog H2T(t-Bu)P. The other porphyrins investigated, with different modes of nonplanarity, display smaller temperature variations but also tend toward more normal properties at low temperatures. A more extreme case of perturbation to the tetrapyrrole electronic structure is found in zinc 2,3,5,5',7,8,12,18-octamethyl-13,17-bis(3-methoxy-3-oxopropyl)isoporphyrin perchlorate, a porphyrin tautomer with an interrupted st system. This zinc isoporphyrin also exhibits a short excited state lifetime of 130 ps at 296 K, which again increases to 0.8 ns at 78 K. The results for the various nonplanar porphyrins and for the isoporphyrin in several solvents indicate that the principal cause of the altered excited state Lifetimes is the ability of the molecules to traverse multiple conformational surfaces in the excited state. These surfaces appear to be separated by only small energy barriers that vary with the types of conformational distortions and their concomitant perturbations of the electronic structures of the chromophores. C1 WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. UNIV CALIF DAVIS,DEPT CHEM,DAVIS,CA 95616. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RI Medforth, Craig/D-8210-2013; REQUIMTE, FMN/M-5611-2013; REQUIMTE, UCIBIO/N-9846-2013; Smith, Kevin/G-1453-2011 OI Medforth, Craig/0000-0003-3046-4909; Smith, Kevin/0000-0002-6736-4779 NR 42 TC 115 Z9 116 U1 2 U2 9 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 FEB 13 PY 1997 VL 101 IS 7 BP 1247 EP 1254 DI 10.1021/jp9631137 PG 8 WC Chemistry, Physical SC Chemistry GA WL114 UT WOS:A1997WL11400021 ER PT J AU Bednarczyk, P Styczen, J Broda, R Lach, M Meczynski, W Nazarewicz, W Ormand, WE Satula, W Bazzacco, D Brandolini, F deAngelis, G Lunardi, S Muller, L Medina, NH Petrache, CM Alvarez, CR Scarlassara, F Segato, GF Signorini, C Soramel, F AF Bednarczyk, P Styczen, J Broda, R Lach, M Meczynski, W Nazarewicz, W Ormand, WE Satula, W Bazzacco, D Brandolini, F deAngelis, G Lunardi, S Muller, L Medina, NH Petrache, CM Alvarez, CR Scarlassara, F Segato, GF Signorini, C Soramel, F TI High spin states in Sc-45 and coexistence of collective and non-collective structures in the odd-A f(7/2) nuclei SO PHYSICS LETTERS B LA English DT Article DE gamma rays and mass spectroscopy; DSAM lifetime measurements; high spins; Shell model; nuclear deformation ID SHELL-MODEL; 0F1P SHELL; CR-49 AB High-spin states in Ca-43, Sc-45, and Ti-45 were studied with the GASP multidetector array coupled with the Recoil Mass Spectrometer. The nuclei were excited in the 60 MeV O-18 + Si-30 reaction. Lifetimes were extracted from the analysis of the Doppler-shift attenuation of gamma-rays observed in the reversed Cl-35 + C-12 reaction. The Lifetimes, B(MI) and B(E2) values for Sc-45 are presented. The measurements suggest significant deformation of the positive-parity intruder band in this nucleus. The band is predicted by the mean-field calculations to be the cross-shell particle-hole excitation associated with a strong quadrupole core-polarization. Spherical shell-model calculations reproduce observed excitation energies and transition rates in both spherical and deformed structures. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV WARSAW,INST THEORET PHYS,PL-00681 WARSAW,POLAND. UNIV PADUA,DIPARTIMENTO FIS,PADUA,ITALY. IST NAZL FIS NUCL,PADUA,ITALY. IST NAZL FIS NUCL,LAB NAZL LEGNARO,I-35020 LEGNANO,ITALY. UNIV UDINE,DIPARTIMENTO FIS,I-33100 UDINE,ITALY. IST NAZL FIS NUCL,UDINE,ITALY. RP Bednarczyk, P (reprint author), INST NUCL PHYS,UL RADZIKOWSKIEGO 152,PL-31342 KRAKOW,POLAND. RI Petrache, Costel/E-9867-2012; Medina, Nilberto/D-8992-2012; OI Petrache, Costel/0000-0001-8419-1390; Medina, Nilberto/0000-0003-0650-6507; Scarlassara, Fernando/0000-0002-4663-8216 NR 24 TC 20 Z9 20 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 FEB 13 PY 1997 VL 393 IS 3-4 BP 285 EP 289 DI 10.1016/S0370-2693(96)01635-8 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WJ458 UT WOS:A1997WJ45800005 ER PT J AU Acciarri, M Adriani, O AguilarBenitez, M Ahlen, S Alpat, B Alcaraz, J Alemanni, G Allaby, J Alosio, 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 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 Kubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mafia, 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 Alosio, 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 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 Kubelsmeyer, K Luci, C Luckey, D Luminari, L Lustermann, W Ma, WG Maity, M Majumder, G Malgeri, L Malinin, A Mafia, 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 Measurement of inclusive omega and eta' production in hadronic Z decays SO PHYSICS LETTERS B LA English DT Article ID BOSE-EINSTEIN CORRELATIONS; LUND MONTE-CARLO; E+E ANNIHILATION; JET FRAGMENTATION; ENERGY REGION; L3 EXPERIMENT; MIXING ANGLE; QCD; RESONANCE; PHYSICS AB We present a study of the inclusive omega and eta' production based on 3.1 million hadronic Z decays recorded with the L3 detector at LEP during 1991-1994. The production rates per hadronic Z decay have been measured to be 1.17+/-0.17 omega mesons and 0.25+/-0.04 eta' mesons. The production rates and the differential cross sections have been compared with predictions of the JETSET and the HERWIG Monte Carlo models. We have observed that the differential cross sections can be described by an analytical quantum chromodynamics calculation. C1 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, LAPP, 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. UNIV SCI & TECHNOL CHINA, 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, INST PHYS NUCL LYON, IN2P3, CNRS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. IST NAZL FIS NUCL, I-20133 MILAN, ITALY. 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. CATHOLIC UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. INST PHYS NUCL, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULAS ELEMENTALES, E-15706 SANTIAGO DE COMPOSTELA, SPAIN. BULGARIAN ACAD SCI, CENT LAB MECHATRON & INSTRUMENTAT, BU-1113 SOFIA, BULGARIA. KOREA ADV INST SCI & TECHNOL, CTR HIGH ENERGY PHYS, TAEJON 305701, SOUTH KOREA. UNIV ALABAMA, TUSCALOOSA, AL 35486 USA. UNIV UTRECHT, NL-3584 CB UTRECHT, NETHERLANDS. NIKHEF 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 RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. RI Ferguson, Thomas/O-3444-2014; Berdugo, Javier/A-2858-2015; Fiandrini, Emanuele/C-4549-2008; 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; 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 OI 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; Vogel, Helmut/0000-0002-6109-3023; 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 NR 35 TC 18 Z9 18 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 FEB 13 PY 1997 VL 393 IS 3-4 BP 465 EP 476 DI 10.1016/S0370-2693(96)01683-8 PG 12 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WJ458 UT WOS:A1997WJ45800032 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, SG 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, SG 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 Study of the weak charged hadronic current in b decays SO PHYSICS LETTERS B LA English DT Article AB Charged and neutral particle multiplicities of jets associated with identified semileptonic and hadronic b decays are studied. The observed differences between these jets are used to determine the inclusive properties of the weak charged hadronic current. The average charged particle multiplicity of the weak charged hadronic current in b decays is measured for the first time to be 2.69+/-0.07(stat.) +/-0.14(syst.). This result is in good agreement with the JETSET hadronization model of the weak charged hadronic current if 40+/-7% of the produced mesons are light-flavored tensor (L=1) mesons, This level of tensor meson production is consistent with the measurement of the pi(0) multiplicity in the weak charged hadronic current in b decays. C1 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, LAPP, 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. UNIV SCI & TECHNOL CHINA, 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, INST PHYS NUCL LYON, IN2P3, CNRS, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. IST NAZL FIS NUCL, I-20133 MILAN, ITALY. 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. CATHOLIC UNIV NIJMEGEN, NL-6525 ED NIJMEGEN, NETHERLANDS. NATL INST NUCL PHYS & HIGH ENERGY PHYS, NL-6525 ED NIJMEGEN, NETHERLANDS. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. CALTECH, PASADENA, CA 91125 USA. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. CARNEGIE MELLON UNIV, PITTSBURGH, PA 15213 USA. PRINCETON UNIV, PRINCETON, NJ 08544 USA. IST NAZL FIS NUCL, I-00185 ROME, ITALY. UNIV ROMA LA SAPIENZA, I-00185 ROME, ITALY. RUSSIAN ACAD SCI, INST NUCL PHYS, ST PETERSBURG, RUSSIA. UNIV SALERNO, I-84100 SALERNO, ITALY. IST NAZL FIS NUCL, I-84100 SALERNO, ITALY. UNIV CALIF SAN DIEGO, SAN DIEGO, CA 92093 USA. UNIV SANTIAGO, DEPT FIS PARTICULES 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 RHEIN WESTFAL TH AACHEN, INST PHYS 1, D-52056 AACHEN, GERMANY. 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; Ferguson, Thomas/O-3444-2014; Lista, Luca/C-5719-2008; Berdugo, Javier/A-2858-2015; 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 OI Castellini, Guido/0000-0002-0177-0643; Diemoz, Marcella/0000-0002-3810-8530; 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; Behner, Frank/0000-0002-2432-2851; 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; 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; Vogel, Helmut/0000-0002-6109-3023 NR 15 TC 0 Z9 0 U1 0 U2 5 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 FEB 13 PY 1997 VL 393 IS 3-4 BP 477 EP 486 DI 10.1016/S0370-2693(96)01689-9 PG 10 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WJ458 UT WOS:A1997WJ45800033 ER PT J AU LeonEscamilla, EA Hurng, WM Peterson, ES Corbett, JD AF LeonEscamilla, EA Hurng, WM Peterson, ES Corbett, JD TI Synthesis, structure, and properties of Ca16Sb11, a complex zintl phase. Twelve other isotypic compounds formed by divalent metals and pnictogens SO INORGANIC CHEMISTRY LA English DT Article ID ALKALINE-EARTH AB The systems A=Ca, Sr, Ba, Eu, Yb and Pn=As, Sb, Bi form isostructural A(16)Pn(11) phases for all but Ba-As and Yb-As when the elements are reacted in Ta containers at about 1100 degrees C and then annealed at 825-900 degrees C or slowly cooled. It is important to run particularly the Ae(16)Sb(11) reactions for Ae=Ca, Sr, Ba either under dynamic vacuum or to previously remove the pervasive hydrogen impurity from these metals. The tetragonal structure type was defined for Ca16Sb11 (, Z=2, a=12.253(3) Angstrom, c=11.313(4) Angstrom). The complex structure is built of pairs of confacial W5Si3-like slabs intergrown with single square-prismatic slabs along <(c)over arrow> in which Ca atoms in both define the polyhedra centered by Sb. This structure is the missing n=2 member of the homologous series A(5n+6)B(3n+5)(Parthe) with n:1 ratios of intergrown slabs. Four of five Ae(16)(Sb,Bi)(11) examples studied are diamagnetic (Ba16Sb11 excepted), and Ca16Sb11 is a poor semiconductor. Accommodation of these Zintl-phase characteristics in the Ca16Sb11 structure requires that 50% of the Sb atom pairs centering the confacial square antiprisms be bonded (d=3.40 Angstrom) on a random basis. Ellipsoids on these atoms are elongated along the proposed bonds. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DOE,AMES,IA 50011. NR 38 TC 29 Z9 29 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD FEB 12 PY 1997 VL 36 IS 4 BP 703 EP 710 DI 10.1021/ic961035w PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WH537 UT WOS:A1997WH53700031 ER PT J AU Fornstedt, T Sajonz, P Guiochon, G AF Fornstedt, T Sajonz, P Guiochon, G TI Thermodynamic study of an unusual chiral separation. Propranolol enantiomers on an immobilized cellulase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PERFORMANCE LIQUID-CHROMATOGRAPHY; MOBILE PHASE-COMPOSITION; BOVINE SERUM-ALBUMIN; CBH-I-SILICA; STATIONARY-PHASE; NONLINEAR CHROMATOGRAPHY; TEMPERATURE-DEPENDENCE; CELLOBIOHYDROLASE-I; BAND PROFILES; RETENTION AB The thermodynamics of interaction of (R)- and (S)-propranolol between an acetic acid buffer (pH = 4.7 and 5.5) and the protein cellobiohydrolase I immobilized on silica gel was studied between 5 and 45 degrees C. The equilibrium data were fitted To a biLangmuir adsorption isotherm with excellent agreement. One of the two Langmuir contributions is the same for both enantiomers and accounts for the nonspecific interactions between these compounds and most sites on the surfaces (type-I, nonselective sites). It has a large saturation capacity, The second contribution accounts for the chiral selective interactions (type-II sites). It has a lower monolayer capacity than the first. The interaction enthalpy and entropy on type-I sites are -1.1 kcal/mol and +0.1 cay(mol K), repectively. For type-II sites, they are -1.9 kcal/mol and -2.6 cal/(mol K), respectively, for (R)-propranolol and +1.6 kcal/mol and +11.6 call(mol K), respectively, for (S)-propranolol at pH = 5.5. This explains why at this pH the retention time of the less-retained R enantiomer decreases with increasing temperature, while the retention time of the S enantiomer increases, causing a large increase of the separation factor when the temperature is raised from 5 to 45 degrees C. The saturation capacity of the chiral contributions depends strongly on the pH, and the retention times of both enantiomers decrease with increasing temperature at pH = 4.7. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. UNIV UPPSALA BMC,S-75123 UPPSALA,SWEDEN. OI Fornstedt, Torgny/0000-0002-7123-2066 NR 46 TC 135 Z9 135 U1 0 U2 17 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 FEB 12 PY 1997 VL 119 IS 6 BP 1254 EP 1264 DI 10.1021/ja9631458 PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA WH326 UT WOS:A1997WH32600010 ER PT J AU Peters, JW Stowell, MHB Soltis, SM Finnegan, MG Johnson, MK Rees, DC AF Peters, JW Stowell, MHB Soltis, SM Finnegan, MG Johnson, MK Rees, DC TI Redox-dependent structural changes in the nitrogenase P-cluster SO BIOCHEMISTRY LA English DT Article ID MOLYBDENUM-IRON PROTEIN; AZOTOBACTER-VINELANDII NITROGENASE; MOFE PROTEIN; CRYSTALLOGRAPHIC STRUCTURE; CLOSTRIDIUM-PASTEURIANUM; EPR; FE; REFINEMENT; RESOLUTION; DINITROGEN AB The structure of the nitrogenase MoFe-protein from Azotobacter vinelandii has been refined to 2.0 Angstrom resolution in two oxidation states. EPR studies on the crystals indicate that the structures correspond to the spectroscopically assigned oxidized (p(OX)/M(OX)) and the native or dithionite-reduced (P(N)/M(N)) forms of the enzyme, Both MoFe-protein structures are essentially identical, with the exception of the P-cluster. The MoFe-protein P-cluster in each state is found to contain eight Fe and seven S atoms. Interconversion between the two redox states involves movement of two Fe atoms and an exchange of protein coordination for ligands supplied by a central S atom. In the oxidized P(OX) state, the cluster is coordinated by the protein through six cysteine ligands, Ser-beta 188 O gamma, and the backbone amide of Cys-alpha 88. In the native P(N) state, Ser-beta 188 O gamma and the amide N of Cys-alpha 88 no longer coordinate the cluster due to movement of their coordinated Fe atoms toward the central sulfur. Consequently, this central sulfur adopts a distorted octahedral environment with six surrounding Fe atoms. A previously described model of the P-cluster containing 8Fe-8S likely reflects the inappropriate modeling of a single structure to a mixture of these two P-cluster redox states, These observed redox-mediated structural changes of the P-cluster suggest a role for this cluster in coupling electron transfer and proton transfer in nitrogenase. C1 CALTECH, DIV CHEM & CHEM ENGN, PASADENA, CA 91125 USA. STANFORD UNIV, STANFORD SYNCHROTRON RADIAT LAB, SLAC, PALO ALTO, CA 94309 USA. UNIV GEORGIA, DEPT CHEM, ATHENS, GA 30602 USA. UNIV GEORGIA, CTR METALLOENZYME STUDIES, ATHENS, GA 30602 USA. OI Peters, John/0000-0001-9117-9568 FU NIGMS NIH HHS [GM18142, GM51962] NR 37 TC 322 Z9 328 U1 5 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD FEB 11 PY 1997 VL 36 IS 6 BP 1181 EP 1187 DI 10.1021/bi9626665 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WH050 UT WOS:A1997WH05000001 PM 9063865 ER PT J AU Tucker, DL Oemler, A Kirshner, RP Lin, H Shectman, SA Landy, SD Schechter, PL Muller, V Gottlober, S Einasto, J AF Tucker, DL Oemler, A Kirshner, RP Lin, H Shectman, SA Landy, SD Schechter, PL Muller, V Gottlober, S Einasto, J TI The Las Campanas Redshift Survey galaxy-galaxy autocorrelation function SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE surveys; galaxies, clusters, general; cosmology, observations; large-scale structure of Universe ID POWER-SPECTRUM; BIAS AB Measurements are presented of the observed redshift-space galaxy-galaxy autocorrelation function, xi(gg)(s), for the Las Campanas Redshift Survey (LCRS). For separations 2.015 mm/yr) slip along the RZT at similar to 10 Ma is capable of explaining the initial portion of the K-feldspar age spectra, a prior common thermal history experienced by all samples cannot satisfactorily account for all the Ar-40/Ar-39 results. Instead, we find our thermal history constraints to be more completely explained by a numerical model in which (1) rocks currently at the surface originated from different depths,(2) footwall samples in close proximity to the RZT experienced fault drag from 19 to 15 Ma and (3) post-thrusting denudation of the region involving localized tilting occurred at similar to 10 Ma. The minimum average slip rate and displacement along the ramp during this period are 2 mm/yr and 12 km, respectively, but are likely to have been greater. The cooling episode recorded in all the K-feldspar age spectra beginning at similar to 10 Ma may either reflect denudation following regional uplift due to displacement along the ramp of the Main Himalayan Thrust or topographic collapse following cessation of RZT thrusting. C1 UNIV CALIF BERKELEY, DEPT EARTH & SPACE SCI, LOS ANGELES, CA USA. UNIV CALIF LOS ANGELES, INST GEOPHYS & PLANETARY PHYS, LOS ANGELES, CA 90024 USA. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. RI Harrison, Timothy/E-7443-2012; Yin, An/B-3050-2014; UCLA, SIMS/A-1459-2011 NR 44 TC 156 Z9 167 U1 1 U2 12 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 FEB 10 PY 1997 VL 102 IS B2 BP 2659 EP 2679 DI 10.1029/96JD02483 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WH694 UT WOS:A1997WH69400002 ER PT J AU Staunton, JB Ling, MF Johnson, DD AF Staunton, JB Ling, MF Johnson, DD TI A theoretical treatment of atomic short-range order and magnetism in iron-rich bcc alloys SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID DIFFUSE NEUTRON-SCATTERING; SINGLE-CRYSTAL; ELECTRONIC-STRUCTURE; 1ST-PRINCIPLES THEORY; METALLIC ALLOYS; PARAMAGNETIC ALLOYS; TRANSITION-METALS; CURIE-TEMPERATURE; MOMENTS; ORIGIN AB We use a 'first-principles' concentration-wave approach based on a finite-temperature, electronic density-functional, mean-field, grand potential of the random alloy to investigate the atomic short-range order (ASRO) in some FeV and FeAl solid solutions in both ferromagnetic and paramagnetic phases. Thermally induced spin fluctuations are modelled in terms of local moments on the Fe sites. This picture produces satisfactory estimates of all of the alloys' Curie temperatures, T-c. We compare our calculations with the ASRO deduced from neutron and x-ray diffuse scattering measurements on single crystals carried out either in situ at or quenched from temperatures above and below T-c. Our calculations describe the measured ASRO well. Both alloy systems exhibit B2-type ordering correlations in their paramagnetic states which strengthen in the case of FeV and weaken for FeAl as the temperature is lowered into the ferromagnetic state. We extract electronic mechanisms for these effects. The ASROs of the ferromagnetic alloys also show intensity around (1/2, 1/2, 1/2) which is traced to a Fermi surface feature and may be a precursor to the DO3 ordering in FeAl. Finally, suggestions for further polarized neutron, in situ measurements are made. C1 MONASH UNIV,DEPT PHYS,CLAYTON,VIC 3168,AUSTRALIA. SANDIA NATL LABS,COMPUTAT MAT SCI DEPT,LIVERMORE,CA. RP Staunton, JB (reprint author), UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. OI Johnson, Duane/0000-0003-0794-7283 NR 50 TC 18 Z9 18 U1 0 U2 8 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD FEB 10 PY 1997 VL 9 IS 6 BP 1281 EP 1300 DI 10.1088/0953-8984/9/6/014 PG 20 WC Physics, Condensed Matter SC Physics GA WK618 UT WOS:A1997WK61800014 ER PT J AU Alamo, RG Graessley, WW Krishnamoorti, R Lohse, DJ Londono, JD Mandelkern, L Stehling, FC Wignall, GD AF Alamo, RG Graessley, WW Krishnamoorti, R Lohse, DJ Londono, JD Mandelkern, L Stehling, FC Wignall, GD TI Small angle neutron scattering investigations of melt miscibility and phase segregation in blends of linear and branched polyethylenes as a function of the branch content SO MACROMOLECULES LA English DT Article ID LOW-DENSITY POLYETHYLENE; POLYMER BLENDS; MOLECULAR-WEIGHT; STATE; THERMODYNAMICS; SEPARATION; DEPENDENCE; BEHAVIOR; MIXTURES; CHAINS AB We have performed a series of small angle neutron scattering (SANS) experiments on blends of linear and branched polyethylenes to investigate the level of branching that is required to phase separate the system. These results confirm that the mixtures are homogenous for all compositions when the branch content is low (i.e., <4 branches/100 backbone carbon atoms for molecular weight M(w) similar to 10(5)). However, when the branch content is higher (typically greater than or equal to 8 branches/100 backbone carbons), the blends phase separate. Segregation can also be driven by isotope effects, when the molecular weight is sufficiently high so that the product of the polymerization index and the H-1/D-2 interaction parameter (N chi(HD)) > 2. In each case, the resolution of conventional SANS pinhole cameras (Q(main) similar to 10(-3) Angstrom(-1)) is adequate to determine the state of mixing, even for systems with large domains. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. FLORIDA STATE UNIV,COLL ENGN,TALLAHASSEE,FL 32310. FLORIDA AGR & MECH,DEPT CHEM ENGN,TALLAHASSEE,FL 32310. PRINCETON UNIV,DEPT CHEM ENGN,PRINCETON,NJ 08544. CORNELL UNIV,DEPT MAT SCI & ENGN,ITHACA,NY 14853. EXXON RES & ENGN CO,CORP RES LABS,ANNANDALE,NJ 08801. FLORIDA STATE UNIV,INST MOL BIOPHYS,DEPT CHEM,TALLAHASSEE,FL 32306. EXXON CHEM CO,PLAST TECHNOL DIV,BAYTOWN,TX 77522. RI Krishnamoorti, Ramanan/F-7914-2011; OI Krishnamoorti, Ramanan/0000-0001-5831-502X; Wignall, George/0000-0002-3876-3244 NR 35 TC 119 Z9 124 U1 1 U2 27 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0024-9297 J9 MACROMOLECULES JI Macromolecules PD FEB 10 PY 1997 VL 30 IS 3 BP 561 EP 566 DI 10.1021/ma961196j PG 6 WC Polymer Science SC Polymer Science GA WH384 UT WOS:A1997WH38400031 ER PT J AU Castilla, GE Chakravarty, S AF Castilla, GE Chakravarty, S TI Is the phase transition in the Heisenberg model described by the (2+epsilon) expansion of the non-linear sigma-model? SO NUCLEAR PHYSICS B LA English DT Article DE Renormalization Group; (2 + epsilon) expansion; O(N) non-linear sigma model; Heisenberg model ID HIGH-GRADIENT OPERATORS; 2 DIMENSIONS; ANOMALOUS DIMENSIONS; FERROMAGNETS; SYMMETRY; SYSTEM AB The non-linear sigma-model is a ubiquitous model. In this paper, the O(N) model where the N-component spin is a unit vector, S-2 = 1, is considered. The stability of this model with respect to gradient operators (partial derivative(mu)S . partial derivative(nu)S)(s), where the degree s is arbitrary, is discussed. Explicit two-loop calculations within the scheme of epsilon-expansion, where epsilon = (d - 2), leads to the surprising result that these operators are relevant. In fact, the relevance increases with the degree s. We argue that this phenomenon in the O(N) model actually reflects the failure of the perturbative analysis, that is, the (2 + epsilon) expansion. It is likely that it is necessary to take into account non-perturbative effects if one wants to describe the phase transition of the Heisenberg model: within the context of the non-linear sigma-model. Thus, uncritical use of the (2 + epsilon) expansion may be misreading, especially for those cases for which there are not many independent checks. C1 BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. UNIV CALIF LOS ANGELES,DEPT PHYS & ASTRON,LOS ANGELES,CA 90095. NR 43 TC 19 Z9 19 U1 0 U2 3 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 10 PY 1997 VL 485 IS 3 BP 613 EP 645 DI 10.1016/S0550-3213(96)00617-7 PG 33 WC Physics, Particles & Fields SC Physics GA WH435 UT WOS:A1997WH43500003 ER PT J AU Zhang, XF Sung, YS Miller, DJ Hinds, BJ McNeely, RJ Studebaker, DL Marks, TJ AF Zhang, XF Sung, YS Miller, DJ Hinds, BJ McNeely, RJ Studebaker, DL Marks, TJ TI New structural aspects of Tl2Ba2CaCu2Oy epitaxial thin films grown by MOCVD on LaAlO3 SO PHYSICA C LA English DT Article DE Tl2Ba2CaCu2Oy superconducting thin film; microstructure ID CA-CU-O; RESOLUTION ELECTRON-MICROSCOPY; SUPERCONDUCTING TL2BA2CACU2O8; NEUTRON-DIFFRACTION; MODULATED STRUCTURE; CRYSTAL-STRUCTURE; TL2BA2CA2CU3O10; SYSTEM AB The microstructure of a Tl2Ba2CaCu2Oy (Tl-2212) superconducting thin film grown by metal-organic chemical vapor deposition (MOCVD) on a pseudo-cubic (001) LaAlO3 substrate has been examined by analytical transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). Over large regions, the film is epitaxial and Tl-2212 phase is found to be the major phase. The film/substrate interface is abrupt and smooth on the atomic scale but a strain-field is induced by the lattice mismatch between the film and the substrate. In addition to the intrinsic modulation structure of the Tl-2212 phase, a very different modulation structure has also been found. The space group for the Tl-2212 phase in this thin film was determined to be I4mm rather than I4/mmm as usually reported. The loss of the (001) mirror plant is attributed to a defective Tl-2212 structure in which a considerable amount of Tl vacancies and Tl disorder occurred inhomogeneously in Tl-O layers. The reason for the Tl-deficiency is discussed. C1 ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCONDUCT,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT CHEM,EVANSTON,IL 60208. NORTHWESTERN UNIV,SCI & TECHNOL CTR SUPERCONDUCT,EVANSTON,IL 60208. RP Zhang, XF (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 28 TC 5 Z9 7 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 FEB 10 PY 1997 VL 275 IS 1-2 BP 146 EP 154 DI 10.1016/S0921-4534(96)00695-8 PG 9 WC Physics, Applied SC Physics GA WK156 UT WOS:A1997WK15600018 ER PT J AU He, Q Christen, DK Budai, JD Specht, ED Lee, DF Goyal, A Norton, DP Paranthaman, M List, FA Kroeger, DM AF He, Q Christen, DK Budai, JD Specht, ED Lee, DF Goyal, A Norton, DP Paranthaman, M List, FA Kroeger, DM TI Deposition of biaxially-oriented metal and oxide buffer-layer films on textured Ni tapes: New substrates for high-current, high-temperature superconductors SO PHYSICA C LA English DT Article DE applications of high-T-c; superconductors; grain alignment (texturing); multilayers; thin films ID THICK-FILMS AB Techniques are reported for sputter deposition of biaxially oriented buffer-layers on textured Ni tapes. These buffered tapes can be employed as long, flexible, or large area substrates for biaxially-aligned high-temperature superconductors (HTS) with high critical current density J(c). Using deposition techniques at temperatures as low as 25 degrees C, epitaxial Pd or Pt films were first deposited as a base layer on the textured Ni tapes, followed by deposition of biaxially oriented Ag or CeO2 buffer layers. Using Ar/4%H-2 sputter gas, biaxially oriented CeO2 films were also grown directly on the textured Ni tapes, followed by the epitaxial growth of YSZ films. All the films show both strong in-plane and out-of-plane orientations. The effects of Ni surface smoothness on buffer-layer texture were also investigated. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Christen, David/A-9709-2008; Specht, Eliot/A-5654-2009; Paranthaman, Mariappan/N-3866-2015; Budai, John/R-9276-2016 OI Specht, Eliot/0000-0002-3191-2163; Paranthaman, Mariappan/0000-0003-3009-8531; Budai, John/0000-0002-7444-1306 NR 8 TC 106 Z9 113 U1 2 U2 11 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 10 PY 1997 VL 275 IS 1-2 BP 155 EP 161 DI 10.1016/S0921-4534(96)00705-8 PG 7 WC Physics, Applied SC Physics GA WK156 UT WOS:A1997WK15600019 ER PT J AU Bagger, JA Matchev, KT Pierce, DM Zhang, RJ AF Bagger, JA Matchev, KT Pierce, DM Zhang, RJ TI Gauge and Yukawa coupling unification in models with gauge-mediated supersymmetry breaking SO PHYSICAL REVIEW LETTERS LA English DT Article ID GRAND UNIFICATION; NUCLEON DECAY; SU(5) MODELS; ELECTROWEAK; CONSTANTS; GUTS; SUSY; LEP AB We examine gauge and Yukawa coupling unification in models with gauge-mediated supersymmetry breaking. We work consistently to two-loop order, and include all weak, messenger, and unification-scale threshold corrections. We find that successful unification requires unification-scale threshold corrections that are in conflict with the minimal SU(5) model, but are consistent with the modified missing-doublet SU(5) model for small tan beta, and large tan beta with mu > 0. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. RP Bagger, JA (reprint author), JOHNS HOPKINS UNIV,DEPT PHYS & ASTRON,BALTIMORE,MD 21218, USA. NR 31 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 10 PY 1997 VL 78 IS 6 BP 1002 EP 1005 DI 10.1103/PhysRevLett.78.1002 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800005 ER PT J AU Gavin, S Vogt, R AF Gavin, S Vogt, R TI Charmonium suppression by comover scattering in Pb+Pb collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID NUCLEUS-NUCLEUS COLLISIONS; J/PSI-SUPPRESSION; P-W; HADRON AB The first reports of psi and psi' production from experiment NA50 at the CERN Super Proton Synchrotron are compared to calculations based on a hadronic model of charmonium suppression developed previously. Data on centrality dependence and total cross sections are in good accord with these predictions. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Gavin, S (reprint author), BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973, USA. NR 19 TC 93 Z9 93 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 FEB 10 PY 1997 VL 78 IS 6 BP 1006 EP 1009 DI 10.1103/PhysRevLett.78.1006 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800006 ER PT J AU Mungan, CE Buchwald, MI Edwards, BC Epstein, RI Gosnell, TR AF Mungan, CE Buchwald, MI Edwards, BC Epstein, RI Gosnell, TR TI Laser cooling of a solid by 16 K starting from room temperature SO PHYSICAL REVIEW LETTERS LA English DT Article ID BOSE-EINSTEIN CONDENSATION AB An Yb3+-doped optical fiber is laser cooled in vacuo from 298 to 282 K. Cooling results from anti-Stokes fluorescence of the ytterbium ions after optical pumping at a wavelength of 1015 nm. The sample temperature is deduced from the emission spectrum, which is sensitive to the populations in the excited-state multiplet of the ions. The temperature change is limited by the coupling between the fiber and ambient blackbody radiation, as confirmed when samples suddenly exposed to the pump laser are found to exponentially relax towards thermal steady state with the expected time constants. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 16 TC 95 Z9 109 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 FEB 10 PY 1997 VL 78 IS 6 BP 1030 EP 1033 DI 10.1103/PhysRevLett.78.1030 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800012 ER PT J AU Shen, Z Jenks, CJ Anderegg, J Delaney, DW Lograsso, TA Thiel, PA Goldman, AI AF Shen, Z Jenks, CJ Anderegg, J Delaney, DW Lograsso, TA Thiel, PA Goldman, AI TI Structure and stability of the twofold surface of icosahedral Al-Pd-Mn by low-energy electron diffraction and x-ray photoemission spectroscopy SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUASI-CRYSTALS; AL68PD23MN9; PHASE; LEED; STM AB We have used low-energy electron diffraction and x-ray photoemission spectroscopy to investigate the structure of the twofold surface of icosahedral Al-Pd-Mn. The regrowth of the surface by annealing after sputtering took place in two distinct stages. The first stage was the appearance of a fine-grained surface phase with icosahedral, or near-icosahedral, symmetry. For higher annealing temperatures (above 800 K) a bulk terminated face-centered icosahedral surface was observed. C1 IOWA STATE UNIV,AMES,IA 50011. RP Shen, Z (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. 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 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 10 PY 1997 VL 78 IS 6 BP 1050 EP 1053 DI 10.1103/PhysRevLett.78.1050 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800017 ER PT J AU Tjeng, LH Sinkovic, B Brookes, NB Goedkoop, JB Hesper, R Pellegrin, E deGroot, FMF Altieri, S Hulbert, SL Shekel, E Sawatzky, GA AF Tjeng, LH Sinkovic, B Brookes, NB Goedkoop, JB Hesper, R Pellegrin, E deGroot, FMF Altieri, S Hulbert, SL Shekel, E Sawatzky, GA TI Spin-resolved photoemission anti-ferromagnets: Direct observation of Zhang-Rice singlets in CuO SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTRONIC-STRUCTURE; SUPERCONDUCTIVITY; ABSORPTION; DICHROISM; LA2CUO4; OXIDES; STATE; HOLES; CU2O AB We demonstrate that it is possible to obtain spin-resolved valence band spectra with a very high degree of spin polarization from antiferromagnetic transition metal materials if the excitation light is circularly polarized and has an energy close to the cation 2p(3/2) (L(3)) white line. We are able to unravel the different spin states in the single-particle excitation spectrum of CuO and show that the top of the valence band is of pure singlet character, which provides strong support for the existence and stability of Zhang-Rice singlets in high-T-c superconductors. C1 NYU,DEPT PHYS,NEW YORK,NY 10003. EUROPEAN SYNCHROTRON RADIAT FACIL,F-38043 GRENOBLE,FRANCE. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. RP Tjeng, LH (reprint author), UNIV GRONINGEN,CTR MAT SCI,SOLID STATE PHYS LAB,NIJENBORGH 4,NL-9747 AG GRONINGEN,NETHERLANDS. RI Sawatzky, George/D-2997-2012; de Groot, Frank/A-1918-2009 NR 26 TC 67 Z9 67 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 FEB 10 PY 1997 VL 78 IS 6 BP 1126 EP 1129 DI 10.1103/PhysRevLett.78.1126 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800036 ER PT J AU Li, DQ Pearson, J Bader, SD Vescovo, E Huang, DJ Johnson, PD Heinrich, B AF Li, DQ Pearson, J Bader, SD Vescovo, E Huang, DJ Johnson, PD Heinrich, B TI k-space origin of the long-period oscillation in Fe/Cr multilayers: A photoemission study of epitaxial Cr grown on an Fe(100) whisker SO PHYSICAL REVIEW LETTERS LA English DT Article ID QUANTUM-WELL STATES; MAGNETIC MULTILAYERS; THIN-FILMS; EXCHANGE; MAGNETORESISTANCE; SUPERLATTICES; SUBSTRATE; SURFACE AB The k-space origin of the long-period (18 Angstrom) oscillation in the interlayer magnetic coupling of Fe/Cr(100) multilayers is investigated by means of angle-resolved photoemission by probing quantum well (QW) states at the Fermi energy for epitaxial Cr grown on an Fe(100) whisker at 300 degrees C. The periodicity of the intensity oscillations of the Cr QW states in the vicinity of the d-derived ''lens'' feature of the Fermi surface is 17+/-2 Angstrom. Thus the lens is identified as a prime candidate for the origin of the long period. C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE DEPT,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. SIMON FRASER UNIV,DEPT PHYS,BURNABY,BC V5A 1S6,CANADA. RP Li, DQ (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Bader, Samuel/A-2995-2013 NR 22 TC 41 Z9 41 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 FEB 10 PY 1997 VL 78 IS 6 BP 1154 EP 1157 DI 10.1103/PhysRevLett.78.1154 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800043 ER PT J AU Hagberg, A Meron, E AF Hagberg, A Meron, E TI The dynamics of curved fronts: Beyond geometry SO PHYSICAL REVIEW LETTERS LA English DT Article ID REACTION-DIFFUSION SYSTEM; SELF-REPLICATING SPOTS; EXCITABLE MEDIA; PATTERN-FORMATION; SPIRAL WAVES; BIFURCATIONS; TRANSITION AB We derive a new set of kinematic equations for front motion in two-dimensional bistable media The equations generalize the geometric approach by complementing the equation for the front curvature with an order parameter equation associated with a nonequilibrium Ising-Bloch bifurcation. The resulting equations capture the core structure of spiral waves and spontaneous spiral-wave nucleation. C1 BEN GURION UNIV NEGEV,JACOB BLAUSTEIN INST DESERT RES,IL-84990 SEDE BOQER,ISRAEL. BEN GURION UNIV NEGEV,DEPT PHYS,IL-84990 SEDE BOQER,ISRAEL. RP Hagberg, A (reprint author), LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES & T7,LOS ALAMOS,NM 87545, USA. RI MERON, EHUD/F-1810-2012 NR 25 TC 32 Z9 33 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 FEB 10 PY 1997 VL 78 IS 6 BP 1166 EP 1169 DI 10.1103/PhysRevLett.78.1166 PG 4 WC Physics, Multidisciplinary SC Physics GA WG888 UT WOS:A1997WG88800046 ER PT J AU Song, S Yoon, M Mochrie, SGJ Stephenson, GB Milner, ST AF Song, S Yoon, M Mochrie, SGJ Stephenson, GB Milner, ST TI Faceting kinetics of stepped Si(113) surfaces: Dynamic scaling and nano-scale grooves SO SURFACE SCIENCE LA English DT Article DE faceting; models of surface kinetics; silicon; stepped single crystal surfaces; surface structure, morphology, roughness, and topography; x-ray scattering diffraction and reflection ID X-RAY-SCATTERING; ORIENTATIONAL PHASE-DIAGRAM; SCANNING-TUNNELING-MICROSCOPY; ENERGY-ELECTRON-DIFFRACTION; EQUILIBRIUM CRYSTAL SHAPES; VICINAL SI(111); SI SURFACES; SPINODAL DECOMPOSITION; RENORMALIZATION-GROUP; CRITICAL-BEHAVIOR AB Time-resolved synchrotron X-ray scattering studies are presented of the faceting kinetics of stepped silicon surfaces misoriented by 2.1 degrees and 1.3 degrees from the cubic [113] direction towards the [001] direction. Following a quench from the high-temperature one-phase region of the orientational phase diagram into the two-phase coexistence region, originally-uniformly-distributed steps rearrange to form a grooved superstructure. Time-resolved surface X-ray scattering measurements reveal the behavior of the grooved surface morphology as a function of time. For times up to several hundred seconds after a quench, the behaviors of the specular and diffuse scattering intensity support a dynamic scaling description of the surface morphology. Specifically, the surface is found to be selfsimilar in time, with a characteristic groove side (L) varying as a power-law versus time (t): L=L(o)t(phi) with a coarsening exponent of phi = 0.164 +/- 0.021 similar or equal to 1/6. phi = 1/6 is consistent with a theory which focuses on thermally fluctuating step bunches and lakes their collisions as the key growth mechanism. At later times, the groove size approaches a limiting value which depends on the stepped phase misorientation angle. This is consistent with the behavior expected for faceted surfaces in the case that elastic effects are important [V.I. Marchenko, Zh. Eksp. Teor. Fiz. 81 (1981) 1141]. C1 MIT,DEPT PHYS,CAMBRIDGE,MA 02139. MIT,ELECT RES LAB,CAMBRIDGE,MA 02139. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. EXXON RES & ENGN CO,CORP RES SCI LAB,ANNANDALE,NJ 08801. NR 89 TC 41 Z9 41 U1 1 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 10 PY 1997 VL 372 IS 1-3 BP 37 EP 63 DI 10.1016/S0039-6028(96)01106-5 PG 27 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WF207 UT WOS:A1997WF20700019 ER PT J AU Mullins, DR Tang, T Chen, X Shneerson, V Saldin, DK Tysoe, WT AF Mullins, DR Tang, T Chen, X Shneerson, V Saldin, DK Tysoe, WT TI The adsorption site and orientation of CH3S and sulfur on Ni(001) using angle-resolved X-ray photoelectron spectroscopy SO SURFACE SCIENCE LA English DT Article DE chemisorption; computer simulations; low index single crystal surfaces; nickel; photoelectron diffraction; soft X-ray photoelectron spectroscopy; thiols ID ENERGY ION-SCATTERING; METHYL THIOLATE; METHANETHIOL; DECOMPOSITION; NI(111); W(001); SURFACES; NICKEL AB Photoelectron diffraction from the S 2p core level has been used to determine the adsorption site and orientation of sulfur and methyl thiolate (CH3S) on Ni(001) by comparing the experimental data with the results of multiple scattering calculations. The theory was initially checked for atomic S, which is known to adsorb in the four-fold hollow site on Ni(001), and the results corresponded to the correct geometry. Comparison of calculated spectra with the experimental data indicates that chemisorbed atomic sulfur is located at 1.30 +/- 0.01 Angstrom above the first layer of nickel atoms on the (001) plane. At 100 K, CH3S adsorbs in the four-fold site on Ni(001), where the C-S bond is proposed to be oriented along the surface normal on Ni(001). A comparison between calculated and experimental results demonstrate that the C-S bond in adsorbed methyl thiolate is oriented perpendicular to the surface and is 1.85 +/- 0.1 Angstrom long. C1 UNIV WISCONSIN,DEPT CHEM,MILWAUKEE,WI 53211. UNIV WISCONSIN,SURFACE STUDIES LAB,MILWAUKEE,WI 53211. UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53211. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. NR 23 TC 23 Z9 23 U1 2 U2 4 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 10 PY 1997 VL 372 IS 1-3 BP 193 EP 201 DI 10.1016/S0039-6028(96)01099-0 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WF207 UT WOS:A1997WF20700032 ER PT J AU Markovic, NM Lucas, CA Gasteiger, HA Ross, PN AF Markovic, NM Lucas, CA Gasteiger, HA Ross, PN TI The structure of adsorbed bromide concurrent with the underpotential deposition (UPD) of Cu on Pt(111) SO SURFACE SCIENCE LA English DT Article ID X-RAY-SCATTERING; SCANNING-TUNNELING-MICROSCOPY; SULFURIC-ACID-SOLUTION; IN-SITU; EX-SITU; COPPER; SURFACE; PLATINUM(111); ELECTRODE; ANIONS AB The adsorption of bromide anions concurrent with the underpotential deposition (UPD) of Cu on Pt(111) was examined utilizing ex-situ LEED and in-situ surface X-ray scattering for structure determination, in combination with coverage determination by rotating ring disk flux measurements with the Pt(111) single crystal as the disk electrode. The results show definitively that Cu UPD on Pt(111) in the presence of bromide is a two-step process, with the total amount of Cu deposited at underpotentials similar to 0.95 +/- 5% ML (1 ML=1 adatom per Pt atom). The results also indicate that the surface coverage by adsorbed bromide undergoes only a small (<0.05 ML) change upon the deposition of Cu, even up to a nominal monolayer. We propose a model wherein the first stage of deposition occurs by displacement of the close-packed hexagonal layer of Pr adatoms by Cu adatoms through a ''turn-over'' process, in which Cu is sandwiched between the Pt surface and the Pr overlayer, leading to the formation of an ordered Pt(111)-Cu-Br bilayer intermediate phase which closely resembles the (111) planes of the Cu(I)Br crystal. The coverage of both Cu and Pr in this intermediate phase is similar to 0.5 ML. The second stage is the filling-in of the Cu plane of the bilayer to form a pseudomorphic (1 x 1) Cu monolayer and a disordered Pr adlayer with a coverage of similar to 0.4 ML. The same mechanism is suggested for Cu UPD on Pt(111) in solutions containing chloride anions. RP Markovic, NM (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. OI Lucas, Christopher/0000-0001-5743-3868 NR 24 TC 32 Z9 32 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 10 PY 1997 VL 372 IS 1-3 BP 239 EP 254 DI 10.1016/S0039-6028(96)01098-9 PG 16 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WF207 UT WOS:A1997WF20700036 ER PT J AU Jacobs, PW Wind, SJ Ribeiro, FH Somorjai, GA AF Jacobs, PW Wind, SJ Ribeiro, FH Somorjai, GA TI Nanometer size platinum particle arrays: Catalytic and surface chemical properties SO SURFACE SCIENCE LA English DT Article DE catalysis; platinum; silicon oxides; surface diffusion; thermal desorption spectroscopy ID ETHYLENE HYDROGENATION; SUPPORTED PLATINUM; SPILLOVER; NANOSTRUCTURES; TPD AB A new type of spatially controlled model catalyst was prepared by electron beam lithography. The catalyst consisted of a square array of disc shaped platinum particles 50 nm in diameter and spaced at 200 nm on an oxidized silicon wafer. The catalyst was cleaned of surface contaminants by low energy neon ion sputtering without adversely altering the characteristics of the array. Catalytic activity was confirmed by performing ethylene hydrogenation at high pressure. Evidence of deuterium spillover was seen by thermal desorption experiments. C1 UNIV CALIF BERKELEY,DEPT CHEM,DIV MAT SCI,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94704. IBM CORP,THOMAS J WATSON RES CTR,YORKTOWN HTS,NY 10598. NR 14 TC 35 Z9 35 U1 0 U2 10 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 10 PY 1997 VL 372 IS 1-3 BP L249 EP L253 DI 10.1016/S0039-6028(96)01268-X PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA WF207 UT WOS:A1997WF20700001 ER PT J AU Tobiason, FL Kelley, SS Midland, MM Hemingway, RW AF Tobiason, FL Kelley, SS Midland, MM Hemingway, RW TI Temperature dependence of (+)-catechin pyran ring proton coupling constants as measured by NMR and modeled using GMMX search methodology SO TETRAHEDRON LETTERS LA English DT Article ID HETEROCYCLIC RING; TETRA-O-METHYL-(+)-CATECHIN; STATE AB The pyran ring proton coupling constants for (+)-catechin have been experimentally determined in deuterated methanol over a temperature range of 213 K to 313 K. The experimental coupling constants were simulated to 0.04 Hz on the average at a 90% confidence limit using a LAOCOON method. The temperature dependence of the coupling constants was reproduced from the Boltzmann distribution of the conformational ensemble generated by the GMMX searching program. (C) 1997, Elsevier Science Ltd. C1 NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. UNIV CALIF RIVERSIDE, DEPT CHEM, RIVERSIDE, CA 92521 USA. US FOREST SERV, USDA, SO RES STN, PINEVILLE, LA 71360 USA. RP Tobiason, FL (reprint author), PACIFIC LUTHERAN UNIV, DEPT CHEM, TACOMA, WA 98447 USA. NR 15 TC 8 Z9 9 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0040-4039 J9 TETRAHEDRON LETT JI Tetrahedron Lett. PD FEB 10 PY 1997 VL 38 IS 6 BP 985 EP 988 DI 10.1016/S0040-4039(96)02505-1 PG 4 WC Chemistry, Organic SC Chemistry GA WG348 UT WOS:A1997WG34800024 ER PT J AU Glass, JT McCann, JF Crothers, DSF Momberger, K AF Glass, JT McCann, JF Crothers, DSF Momberger, K TI Radiative electron capture by relativistic heavy ions SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article ID ATOM COLLISIONS; EMISSION; SHELL AB We present a direct method for calculation of radiative electron capture (REC) X-ray emission in relativistic ion-atom collisions. Results obtained within the distorted-wave impulse approximation (DWIA) are compared with recent experimental data for the collisions of heavy ions with light atoms. Simple closed analytic formulae are derived for small alpha Z describing the polarization and the angular distribution of radiation. Good agreement with recent experiments is found for photoemission rates and angular distributions. Our results for helium and beryllium targets indicate that the photon spectrum is rather insensitive to target structure, but strongly dependent on multiple-scattering corrections, and this contradicts other recent theoretical predictions. In asymmetric collisions our results are in broad agreement with experiment and relativistic impulse approximation (RIA) calculations. Through detailed analysis of magnetic transitions in terms of the electron and photon polarization correlation parameters, important new features are introduced and discussed. C1 QUEENS UNIV BELFAST, THEORET & COMPUTAT PHYS RES DIV, BELFAST BT7 1NN, ANTRIM, NORTH IRELAND. UNIV DURHAM, DEPT PHYS, DURHAM DH1 3LE, ENGLAND. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Glass, JT (reprint author), UNIV GIESSEN, INST THEORET PHYS, D-35392 GIESSEN, GERMANY. NR 28 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD FEB 8 PY 1997 VL 453 IS 1957 BP 387 EP 402 PG 16 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WJ210 UT WOS:A1997WJ21000009 ER PT J AU Yu, S Mangelsdorf, M Hewett, D Hobson, L Baker, E Eyre, HJ Lapsys, N LePaslier, D Doggett, NA Sutherland, GR Richards, RI AF Yu, S Mangelsdorf, M Hewett, D Hobson, L Baker, E Eyre, HJ Lapsys, N LePaslier, D Doggett, NA Sutherland, GR Richards, RI TI Human chromosomal fragile site FRA16B is an amplified AT-rich minisatellite repeat SO CELL LA English DT Article ID X-SYNDROME; MYOTONIC-DYSTROPHY; DNA; GENE; MUTATION; LOCUS; SUSCEPTIBILITY; POLYMORPHISM; ASSOCIATION; INSTABILITY AB Fragile sites are nonstaining gaps in chromosomes induced by specific tissue culture conditions. They vary both in population frequency and in the culture conditions required for induction. Folate-sensitive fragile sites are due to expansion of p(CCG)(n) trinucleotide repeats; however, the relationship between sequence composition and the chemistry of induction of fragile sites is unclear. To clarify this relationship, the distamycin A-sensitive fragile site FRA16B was isolated by positional cloning and found to be an expanded 33 bp AT-rich minisatellite repeat, p(ATATATTATATATTATATCTAATAATATAT(C)/(A)TA)(n) (consistent with DNA sequence binding preferences of chemicals that induce its cytogenetic expression). Therefore the mutation mechanism associated with trinucleotide repeats is also a property of minisatellite repeats (variable number tandem repeats). C1 UNIV ADELAIDE,DEPT GENET,ADELAIDE,SA 5000,AUSTRALIA. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FDN JEAN DAUSSET,CTR ETUD POLYMORPHISME HUMAIN,PARIS,FRANCE. RP Yu, S (reprint author), WOMENS & CHILDRENS HOSP,DEPT CYTOGENET & MOL GENET,CTR MED GENET,ADELAIDE,SA 5006,AUSTRALIA. RI Sutherland, Grant/D-2606-2012; Mangelsdorf, Marie/A-2318-2013 OI Mangelsdorf, Marie/0000-0002-7855-7701 NR 38 TC 147 Z9 148 U1 0 U2 2 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 0092-8674 J9 CELL JI Cell PD FEB 7 PY 1997 VL 88 IS 3 BP 367 EP 374 DI 10.1016/S0092-8674(00)81875-9 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA WG479 UT WOS:A1997WG47900009 PM 9039263 ER PT J AU Lin, H Simon, MN Black, LW AF Lin, H Simon, MN Black, LW TI Purification and characterization of the small subunit of phage T4 terminase, gp16, required for DNA packaging SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID BACTERIOPHAGE-LAMBDA TERMINASE; BACILLUS-SUBTILIS BACTERIOPHAGE-SPP1; SULFATE-POLYACRYLAMIDE GELS; SODIUM DODECYL-SULFATE; ESCHERICHIA-COLI; RNA-POLYMERASE; GENE-PRODUCT; COS DNA; INITIATION; PROTEIN AB Phage T4 terminase is an enzyme that binds to the portal protein of proheads and cuts and packages concatemeric DNA. The T4 terminase is composed of two subunits, gene products (gp) 16 and 17. The role of the small subunit, gp16, in T4 DNA packaging is not well characterized, We developed a new purification procedure to obtain large quantities of purified gp16 from an overexpression vector. The pure protein is found in two molecular weight forms, due to specific C-terminal truncation, displays in vitro packaging activity, and binds but does not hydrolyze ATP, gp16 forms specific oligomers, rings, and side-by-side double rings, as judged by native polyacrylamide gel electrophoresis and scanning transmission electron microscopy measurements. The single ring contains about eight monomers, and the rings have a diameter of about 8 nm with a central hole of about 2 nm. A DNA-binding helix-turn-helix motif close to the N terminus of gp16 is predicted. The oligomers do not bind to DNA, but following denaturation and renaturation in the presence of DNA, binding can be demonstrated by gel shift and filter binding assays, gp16 binds to double-stranded DNA but not single-stranded DNA, and appears to bind preferentially to a gene 16-containing DNA sequence. C1 UNIV MARYLAND, SCH MED, DEPT BIOCHEM, BALTIMORE, MD 21201 USA. UNIV MARYLAND, SCH MED, MOL & CELL BIOL GRAD PROGRAM, BALTIMORE, MD 21201 USA. BROOKHAVEN NATL LAB, DEPT BIOL, UPTON, NY 11973 USA. FU NCRR NIH HHS [RR01777]; NIAID NIH HHS [AI11676] NR 35 TC 56 Z9 60 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 FEB 7 PY 1997 VL 272 IS 6 BP 3495 EP 3501 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WG192 UT WOS:A1997WG19200056 PM 9013596 ER PT J AU Bessho, T Sancar, A Thompson, LH Thelen, MP AF Bessho, T Sancar, A Thompson, LH Thelen, MP TI Reconstitution of human excision nuclease with recombinant XPF-ERCC1 complex SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID REPLICATION PROTEIN-A; TRANSCRIPTION FACTOR; ESCHERICHIA-COLI; REPAIR PROTEINS; FACTOR TFIIH; DNA; PURIFICATION; ERCC1; XPA; BINDING AB The human XPF-ERCC1 protein complex is one of several factors known to be required for general nucleotide excision repair, Genetic data indicate that both proteins of this complex are necessary for the repair of interstrand cross-links, perhaps via recombination, To determine whether XPF-ERCC1 completes a set of six proteins that are sufficient to carry out excision repair, the human XPF and ERCC1 cDNAs were coexpressed in SF21 insect cells from a baculovirus vector, The purified complex contained the anticipated 5' junction-specific endonuclease activity that is stimulated through a direct interaction between XPF and replication protein A (RPA), The recombinant complex also complemented extracts of XP-F cells and Chinese hamster ovary mutants assigned to complementation groups 1, 4, and 11, Furthermore, reconstitution of the human excision nuclease was observed with a mixture of five repair factors (XPA, XPC, XPG, TFIIH, and RPA) and the recombinant XPF-ERCC1, thus verifying that no additional protein factors are needed for the specific dual incisions characteristic of human excision repair. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. UNIV N CAROLINA,SCH MED,DEPT BIOCHEM & BIOPHYS,CHAPEL HILL,NC 27599. RI Thelen, Michael/C-6834-2008; Thelen, Michael/G-2032-2014 OI Thelen, Michael/0000-0002-2479-5480; Thelen, Michael/0000-0002-2479-5480 FU NIGMS NIH HHS [GM52120, GM32833] NR 31 TC 142 Z9 143 U1 0 U2 7 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 FEB 7 PY 1997 VL 272 IS 6 BP 3833 EP 3837 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WG192 UT WOS:A1997WG19200102 PM 9013642 ER PT J AU Somorjai, GA Yang, MX AF Somorjai, GA Yang, MX TI New directions of catalysis research SO JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL LA English DT Article; Proceedings Paper CT 1st Francqui Colloquium on Molecular Heterogeneous Catalysis CY FEB 19-20, 1996 CL BRUSSELS, BELGIUM DE chemical bonding; lithographic techniques; scanning tunneling microscopy; sum frequency generation; surface science ID SINGLE-CRYSTAL SURFACES; SCANNING TUNNELING MICROSCOPE; ETHYLENE HYDROGENATION; REACTOR CELL; THIN-FILMS; PLATINUM; OXIDE; CO; CYCLOHEXENE; OVERLAYERS AB A variety of surface science technologies have been applied on catalysis studies, in an effort to understand surface structure, composition and chemical bonding in catalytic reactions at a molecular level. Many of the characterizations, however, were performed in vacuum before and after the reactions. A new direction in surface science and catalysis is to study the surface structures and surface intermediates in situ during the high pressure/high temperature reactions. Scanning tunneling microscopy (STM) and infrared-visible sum frequency generation (SFG) are viable for the task. In order to obtain a better comprehension of industrial catalysts, model supported catalysts with ordered structures should be introduced into catalysis research. Metal clusters of uniform size and separation can be produced on oxide surfaces by lithographic microfabrication technologies. C1 UNIV CALIF BERKELEY,DIV MAT SCI,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Somorjai, GA (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720, USA. NR 36 TC 17 Z9 17 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 1381-1169 J9 J MOL CATAL A-CHEM JI J. Mol. Catal. A-Chem. PD FEB 7 PY 1997 VL 115 IS 3 BP 389 EP 403 DI 10.1016/S1381-1169(96)00346-9 PG 15 WC Chemistry, Physical SC Chemistry GA WG583 UT WOS:A1997WG58300003 ER PT J AU Lucklum, R Behling, C Cernosek, RW Martin, SJ AF Lucklum, R Behling, C Cernosek, RW Martin, SJ TI Determination of complex shear modulus with thickness shear mode resonators SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article AB The electrical response of polymer-coated acoustic wave sensors depends on changes in the surface mass loading and changes in viscoelastic properties of the coating material. In this paper we consider the acoustic behaviour and the electrical response of a thickness-shear mode resonator on changes in shear parameters of the coating material at its fundamental frequency as well as its third and fifth harmonics. The changes in material properties were induced by temperature changes. Both a glassy and a rubbery polymer were investigated. The complex shear parameter and dynamic glass transition temperature were calculated from impedance measurements. C1 SANDIA NATL LABS,MICROSENSOR RES & DEV DEPT,ALBUQUERQUE,NM 87185. RP Lucklum, R (reprint author), UNIV MAGDEBURG,INST MEASUREMENT TECHNOL,POB 4120,D-39106 MAGDEBURG,GERMANY. NR 19 TC 124 Z9 124 U1 0 U2 16 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD FEB 7 PY 1997 VL 30 IS 3 BP 346 EP 356 DI 10.1088/0022-3727/30/3/006 PG 11 WC Physics, Applied SC Physics GA WK012 UT WOS:A1997WK01200006 ER PT J AU Peurrung, LM Peurrung, AJ AF Peurrung, LM Peurrung, AJ TI The in situ corona for treatment of organic contaminants in soils SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article ID PULSED STREAMER CORONA; AQUEOUS-SOLUTIONS; DISCHARGE; REACTOR; AIR AB The in situ corona is a new technology for destroying a variety of hazardous organic contaminants in soils. Laboratory experiments have revealed the basic physical processes involved in the initiation and operation of treatment. This paper also presents a theoretical model for the in situ corona that agrees with laboratory results. In the in situ corona, resistive dry bands are formed and translated through the entire Volume of soil to be treated. Within the dry bands, an electrical discharge similar in nature to an ordinary gas-phase corona is maintained, destroying organic compounds. Now that we have established a fundamental understanding of the phenomenon in the laboratory, the process may next be scaled up to large treatment volumes in the field. RP Peurrung, LM (reprint author), PACIFIC NW NATL LAB,POB 999,MS P7-41,RICHLAND,WA 99352, USA. NR 28 TC 7 Z9 7 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL, ENGLAND BS1 6BE SN 0022-3727 J9 J PHYS D APPL PHYS JI J. Phys. D-Appl. Phys. PD FEB 7 PY 1997 VL 30 IS 3 BP 432 EP 440 DI 10.1088/0022-3727/30/3/016 PG 9 WC Physics, Applied SC Physics GA WK012 UT WOS:A1997WK01200016 ER PT J AU McCain, WC Lee, R Johnson, MS Whaley, JE Ferguson, JW Beall, P Leach, G AF McCain, WC Lee, R Johnson, MS Whaley, JE Ferguson, JW Beall, P Leach, G TI Acute oral toxicity study of pyridostigmine bromide, permethrin, and DEET in the laboratory rat SO JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH LA English DT Article AB This study investigated the lethal interaction of pyridostigmine bromide (PB), permethrin, and DEET when given to adult male rats by gavage and was separated into two phases. Phase I determined the acute oral lethal dose-response relationship of each compound with the vehicle, propylene glycol. Phase II was divided into two portions: a dose-response study using probit units obtained from phase I [lethal dose (LD) 16, 30, 50, 70, and 84], and an interaction study that contained low levels (calculated LD16, additive LD32) of the two compounds while the concentration of the third compound was varied. Rats were fasted overnight, dosed, and observed for 14 d. A significant increase in lethality occurred when PB, permethrin, and DEET were given concurrently when compared to expected additive values. Furthermore, solutions containing PB and permethrin or PB and DEET also caused a significant increase in lethality when compared to expected additive valuer. This information suggests that lethality in this study was more than an additive effect. C1 OAK RIDGE INST SCI & EDUC,OAK RIDGE,TN. NR 20 TC 52 Z9 53 U1 3 U2 4 PU TAYLOR & FRANCIS PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 0098-4108 J9 J TOXICOL ENV HEALTH JI J. Toxicol. Environ. Health PD FEB 7 PY 1997 VL 50 IS 2 BP 113 EP 124 PG 12 WC Environmental Sciences; Public, Environmental & Occupational Health; Toxicology SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Toxicology GA WJ817 UT WOS:A1997WJ81700003 PM 9048956 ER PT J AU Qualey, DL Welty, JR Drost, MK AF Qualey, DL Welty, JR Drost, MK TI Monte Carlo simulation of radiation heat transfer from an infinite plane to parallel rows of infinitely long tubes - Hottel extended SO NUMERICAL HEAT TRANSFER PART A-APPLICATIONS LA English DT Article AB A two-dimensional Monte Carlo method has been applied to a classic radiant energy exchange problem that models the interior of an industrial furnace. The configuration involves a source as an infinite radiating plane and the heat sink as parallel rows of infinitely long tubes. Hottel used a graphical technique to solve this furnace model for the two-tube-row configuration. This work extends Hottel's results by increasing the number of rows in the original equilateral triangular array and then generalizing the results to isosceles triangular arrangements. C1 OREGON STATE UNIV, DEPT MECH ENGN, CORVALLIS, OR 97331 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 9 TC 7 Z9 7 U1 0 U2 1 PU HEMISPHERE PUBL CORP PI BRISTOL PA 1900 FROST ROAD, SUITE 101, BRISTOL, PA 19007-1598 SN 1040-7782 J9 NUMER HEAT TR A-APPL JI Numer. Heat Tranf. A-Appl. PD FEB 7 PY 1997 VL 31 IS 2 BP 131 EP 142 PG 12 WC Thermodynamics; Mechanics SC Thermodynamics; Mechanics GA WK818 UT WOS:A1997WK81800002 ER PT J AU Steinberg, M AF Steinberg, M TI Disposing of plutonium SO SCIENCE LA English DT Letter RP Steinberg, M (reprint author), BROOKHAVEN NATL LAB,ENGN RES DIV,UPTON,NY 11973, USA. NR 1 TC 0 Z9 0 U1 1 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 FEB 7 PY 1997 VL 275 IS 5301 BP 737 EP 738 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WG777 UT WOS:A1997WG77700003 ER PT J AU Jackson, JD AF Jackson, JD TI History of original ideas and basic discoveries in particle physics - Newman,HB, Ypsilantis,T SO SCIENCE LA English DT Book Review RP Jackson, JD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV PHYS,BERKELEY,CA 94720, USA. NR 1 TC 0 Z9 0 U1 2 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 FEB 7 PY 1997 VL 275 IS 5301 BP 788 EP 788 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WG777 UT WOS:A1997WG77700043 ER PT J AU Ross, SK Sutherland, JW Kuo, SC Klemm, RB AF Ross, SK Sutherland, JW Kuo, SC Klemm, RB TI Rate constants for the thermal dissociation of N2O and the O(P-3)+N2O reaction SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID NITROUS-OXIDE DECOMPOSITION; ATOMIC RESONANCE-ABSORPTION; SHOCK-TUBE TECHNIQUE; FLASH-PHOTOLYSIS; UNIMOLECULAR REACTIONS; + O; KINETICS; O(3P); OXYGEN; SYSTEM AB The thermal dissociation of N2O in argon was investigated by monitoring the formation of O(P-3) atoms in the reflected shock regime using atomic resonance absorption spectrophotometry (ARAS). The total density and [N2O] ranges were, (2.6 x 10(18))-(5.4 x 10(18)) molecules cm(-3) and (3.3 x 10(12))-(7.9 x 10(15)) molecules cm(-3), respectively. Values for the bimolecular rate constant (131 points), derived under low-pressure limit conditions are given by the Arrhenius expression: k(1)(T) = (1.18 +/- 0.16) x 10(-9) exp[(-57820 +/- 460 cal mol(-1))/RT] cm(3) molecule(-1) s(-1) for the temperature range, 1195 less than or equal to T less than or equal to 2384 K. These results extend the low-temperature range of ARAS measurements of k(1) by about 200 degrees C which is very significant in 1/T; and the value of the rate constant was extended by more than an order of magnitude. The present data were combined with previously published ARAS data to form a composite data set with a total of 278 points. Although systematic differences between the data of the various groups were discernible, all the data are well represented by the following Arrhenius equation: k(1)(T) = (9.52 +/- 1.07) x 10(-10) exp[(-57570 +/- 390 cal mol(-1))/RT] cm(3) molecule(-1) s(-1) for the temperature range, 1195 less than or equal to T less than or equal to 2494 K). Uncertainties in the Arrhenius expression are given at the one standard deviation level and the mean deviation of the experimental data from that predicted by the expression is +/-26%. These results are compared to those from previous experimental studies, The rate of the reaction of O(P-3) with N2O was investigated experimentally and by kinetic modeling, but only over a limited temperature range, 1200 less than or equal to T less than or equal to 1400 K. Upper limit values of the overall rate constant for the O(P-3) + N2O reaction were estimated by a statistical technique. These values were about a factor of 10 lower (with an overall uncertainty of about a factor of three) than those calculated from the recommended Arrhenius expressions of Baulch et al. (1973), Hanson and Salimian (1984), and Tsang and Herron (1991). C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. UNIV ABERDEEN,DEPT CHEM,ABERDEEN AB9 2UE,SCOTLAND. NR 65 TC 34 Z9 35 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 FEB 6 PY 1997 VL 101 IS 6 BP 1104 EP 1116 DI 10.1021/jp962416y PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WL090 UT WOS:A1997WL09000018 ER PT J AU Ku, CY LoNostro, P Chen, SH AF Ku, CY LoNostro, P Chen, SH TI Structural study of the gel phase of a semifluorinated alkane in a mixed solvent SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID BEHAVIOR; HYDROCARBONS; SEPARATION; MOLECULES AB Semifluorinated n-alkanes, F3C(CF2)(m-1)(CH2)(n-1)CH3 (for short, FmHn) are short-chain diblock copolymers that show interesting properties when dissolved in nonaqueous media. Due to the high incompatibility between fluorocarbons and hydrocarbons that produces strong immiscibility between fluorocarbons and hydrocarbons, the semifluorinated molecules arrange themselves in peculiar ways both in the solid and in the liquid state. FmHn molecules produce micellar aggregates when dispersed in selective solvents such as perfluorooctane or toluene. They form white gel phases when the liquid solution is cooled down below certain temperatures depending on the concentration of the copolymers. These gels are described as a long network of copolymer fibers that entrap free molecules of solvent in cavities formed between different branches of fibers. In this paper we construct two plausible models for the structure of the gel phase of F8H16 dissolved in a mixture of perfluorooctane/isooctane, and we use them to analyze the small-angle X-ray-scattering (SAXS) data. From quantitative analyses of SAXS intensities in absolute scales, we are able to give the values of various structural parameters of the fiber. C1 UNIV FLORENCE,DIPARTIMENTO CHIM,I-50121 FLORENCE,ITALY. MIT,DEPT NUCL ENGN,CAMBRIDGE,MA 02139. RP Ku, CY (reprint author), ARGONNE NATL LAB,IPNS,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Lo Nostro, Pierandrea/G-6585-2011 NR 16 TC 37 Z9 37 U1 0 U2 7 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 FEB 6 PY 1997 VL 101 IS 6 BP 908 EP 914 DI 10.1021/jp963120v PG 7 WC Chemistry, Physical SC Chemistry GA WL112 UT WOS:A1997WL11200010 ER PT J AU Mullins, DR AF Mullins, DR TI Enhancement of methane formation from methanethiol adsorbed on a strained Ni film on W(001) SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID METHYL THIOLATE; ADSORPTION; DECOMPOSITION; SURFACE; CHEMISTRY AB The selective formation of methane from the decomposition of methanethiol increases as the coverage of Ni thin films is increased from 0 to 2 monolayers (RIL) on W(001). The methane selectivity starts at 30% on the clean W(001) surface, rises to 70% when the Ni coverage is 1 ML, dips to 60% at 1.5 ML, and then continues to rise to >85% when the Ni coverage is 2 ML. This is the largest selectivity for methane formation yet reported for this reaction in ultrahigh vacuum. Accompanying the increase in selectivity is a sequential decrease in the methane desorption temperature. The methane desorbs at 350 K from methanethiol on clean W!001), at 290 K from a 1 ML Ni film, and at 210 K from a 2 ML Ni film. On thick (>5 hin), unannealed films, the desorption temperature increases to 270 K and the selectivity is reduced to 70%. S 2p soft X-ray photoemission indicates that the C-S bond is cleaved between 300 and 350 K on clean W(001) and between 250 and 300 K on a 1 ML Ni film. On the 2 ML Ni film, there is considerable C-S bond cleavage (>50%) at 100 K. The only molecular intermediates are methyl thiolate (CH3S) and hydrocarbon fragments. The methyl thiolate forms at 100 K at all Ni coverages. An amount of 65% of the thiolate occupies low coordination sites on clean W(OO I), while most of the thiolates occupy high coordination sites on the Ni-covered sur-faces. RP Mullins, DR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 25 TC 5 Z9 5 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 FEB 6 PY 1997 VL 101 IS 6 BP 1014 EP 1023 DI 10.1021/jp963150y PG 10 WC Chemistry, Physical SC Chemistry GA WL112 UT WOS:A1997WL11200025 ER PT J AU Egido, JL Robledo, LM Chasman, RR AF Egido, JL Robledo, LM Chasman, RR TI Nuclear shapes in W-176 with density dependent forces: From ground state to fission SO PHYSICS LETTERS B LA English DT Article DE nuclear structure; Gogny force; octupole effects; hyperdeformed shapes; fission ID HARTREE-FOCK; REGION; MODEL; U-238 AB A code appropriate for Hartree-Fock-Bogoliubov calculations in a very large harmonic oscillator basis space has been developed. With a large enough basis, it becomes possible to handle fission in a one-center basis. The code is sufficiently flexible to deal with axially symmetric shapes, including those that are reflection asymmetric. As an application, we have studied the energy surface of the nucleus W-176 for very extended shapes where large reflection asymmetry effects are predicted. The finite range density dependent Gogny force has been used in the calculations. C1 ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. RP Egido, JL (reprint author), UNIV AUTONOMA MADRID,DEPT FIS TEOR CXI,E-28049 MADRID,SPAIN. RI Robledo, Luis Miguel/L-2557-2013; Egido, J. Luis/F-4921-2017 OI Robledo, Luis Miguel/0000-0002-6061-1319; Egido, J. Luis/0000-0002-8292-6127 NR 15 TC 20 Z9 21 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 FEB 6 PY 1997 VL 393 IS 1-2 BP 13 EP 18 DI 10.1016/S0370-2693(96)01602-4 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WJ457 UT WOS:A1997WJ45700003 ER PT J AU Beneke, M Buchalla, G Dunietz, I AF Beneke, M Buchalla, G Dunietz, I TI Mixing-induced CP asymmetries in inclusive B decays SO PHYSICS LETTERS B LA English DT Article ID PENGUIN DIAGRAMS; VIOLATION; MODES AB We consider CP violating asymmetries that are induced by particle-antiparticle mixing in inclusive channels of neutral B meson decay. Not only are the branching ratios sizable, at the 1% to 50% level, but some of these asymmetries are expected to be large because of substantial CKM phases, The inclusive sum partially dilutes the asymmetries, but the dilution factor is calculable. Assuming local quark-hadron duality, the CKM parameters can be extracted. We discuss in detail the determination of sin 2 alpha from charmless final states in decays of B-d mesons and survey the asymmetries for other inclusive final states. The total inclusive time-dependent asymmetry, where all modes of a weakly decaying neutral meson are summed over, is non-vanishing in general and measures Im(Gamma(12)/M(12)). While probably not yet sensitive to standard model predictions, meaningful CP violation studies can be conducted with existing data samples of inclusive neutral B decays. C1 FERMILAB NATL ACCELERATOR LAB,DEPT THEORET PHYS,BATAVIA,IL 60510. RP Beneke, M (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 24 TC 32 Z9 32 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 FEB 6 PY 1997 VL 393 IS 1-2 BP 132 EP 142 DI 10.1016/S0370-2693(96)01648-6 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WJ457 UT WOS:A1997WJ45700022 ER PT J AU Rathsman, J AF Rathsman, J TI Differences between Monte Carlo models for DIS at small-x and the relation to BFKL dynamics SO PHYSICS LETTERS B LA English DT Article DE Monte Carlo models; deep inelastic scattering; small-x; 2+1 Jet cross-section; BFKL dynamics ID DEEP-INELASTIC-SCATTERING; INITIAL STATE RADIATION; EP SCATTERING; CROSS-SECTION; JET RATES; HERA; PROTON; QCD; COHERENCE AB The differences between two standard Monte Carlo models, LEPTO and ARIADNE, for deep inelastic scattering at small-x is analysed in detail. It is shown that the difference arises from a 'unorthodox' suppression factor used in ARIADNE which replaces the normal ratio of parton densities. This gives rise to a factor that qualitatively is similar to what one would expect from BFKL dynamics for some observables like the energy flow and forward jets but not for the 2+1 jet cross-section. It is also discussed how one could use the 2+1 jet cross-section as a probe for BFKL dynamics. RP Rathsman, J (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 43 TC 5 Z9 5 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 FEB 6 PY 1997 VL 393 IS 1-2 BP 181 EP 187 DI 10.1016/S0370-2693(96)01637-1 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA WJ457 UT WOS:A1997WJ45700029 ER PT J AU Cohen, ML AF Cohen, ML TI Density functional theory and pseudopotentials: A panacea for calculating properties of materials SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Article ID BORON-NITRIDE NANOTUBES; CARBON NITRIDE; BAND DISPERSIONS; THIN-FILMS; SUPERCONDUCTIVITY; ELECTRON; SOLIDS; C-60; SI; STABILITY AB Although our microscopic view of solids is still evolving, for a large class of materials one can construct a useful first principles or ''standard model'' of solids which is sufficiently robust to explain and predict many physical properties. Both electronic and structural properties can be studied, and the results of the first-principles calculations can be used to predict new materials, formulate empirical theories and simple formulas to compute material parameters, and explain trends. A discussion of the microscopic approach, applications, and empirical theories is given here, and some recent results on nanotubes, hard materials, and fullerenes are presented. (C) 1997 John Wiley & Sons, Inc. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV SCI MAT, BERKELEY, CA 94720 USA. RP Cohen, ML (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 57 TC 10 Z9 10 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0020-7608 EI 1097-461X J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD FEB 5 PY 1997 VL 61 IS 4 BP 603 EP 611 DI 10.1002/(SICI)1097-461X(1997)61:4<603::AID-QUA1>3.3.CO;2-4 PG 9 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA WC357 UT WOS:A1997WC35700001 ER PT J AU Aizenberg, J Hanson, J Koetzle, TF Weiner, S Addadi, L AF Aizenberg, J Hanson, J Koetzle, TF Weiner, S Addadi, L TI Control of macromolecule distribution within synthetic and biogenic single calcite crystals SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PROTEIN INTERACTIONS; BIOMINERALIZATION AB The ability of organisms to exercise control over crystal growth is wonderfully exemplified by skeleton formation in echinoderms. A sea urchin spine is a unique composite of a single crystal of calcite and glycoproteins intercalated inside the crystal during its growth. Here we performed a detailed morphological and high-resolution synchrotron X-ray diffraction study of the textures of synthetic and biogenic calcite crystals. We show that the intracrystalline macromolecules from sea urchin spines, when allowed to interact with growing calcite crystals in vitro, selectively reduce the coherence lengths and degrees of alignment of the perfect domains in specific crystallographic directions. These directions also correspond to the newly-developed stable faces. In contrast, the defect distribution of young sea urchin spines composed entirely of spongy stereomic structure is much more isotropic. In mature spines containing secondarily filled-in wedges of calcite, the degree of anisotropy is intermediate between that of the synthetic crystals and the young spines. The macromolecules extracted from young and mature spines are, however, very similar. These observations demonstrate the inherent capability of occluded matrix macromolecules to finely differentiate between crystal planes by stereochemical recognition processes. They also show that in biologically-produced calcite crystals this process can be overridden to produce a more isotropic material. C1 WEIZMANN INST SCI,DEPT BIOL STRUCT,IL-76100 REHOVOT,ISRAEL. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RI Hanson, jonathan/E-3517-2010 NR 32 TC 206 Z9 209 U1 4 U2 42 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 FEB 5 PY 1997 VL 119 IS 5 BP 881 EP 886 DI 10.1021/ja9628821 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA WG232 UT WOS:A1997WG23200004 ER PT J AU Elder, SH Lucier, GM Hollander, FJ Bartlett, N AF Elder, SH Lucier, GM Hollander, FJ Bartlett, N TI Synthesis of Au(II) fluoro complexes and their structural and magnetic properties SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CRYSTAL-STRUCTURE; SALTS AB Gold at similar to 20 degrees C with F-2 in anhydrous hydrogen fluoride (aHF) acidified with SbF5 dissolves to a red solution from which orange Au-II(SbF6)(2) crystallizes on removal of volatiles. Au(SbF6)(2) is triclinic with a=5.300(1) Angstrom, b=5.438(1) Angstrom, c=8.768(2) Angstrom, alpha=76.872(3)degrees, beta=88.736(3)degrees, gamma=68.109(3)degrees, V=227.79(7) Angstrom(3), and Z=1, space group . Each Au(II) atom, at (1) over bar, is at the center of an elongated octahedron of F ligands; the four F's of the approximately square AuF4 unit are at 2.09(2) Angstrom x2 Angstrom and 2.15(2) Angstrom x2, each F provided by a different SbF6 species. The two long Au-F interatomic distances are at 2.64(2) Angstrom. The SbF6 are grossly distorted in their interactions with the Au. A cis pair of F ligands of each SbF6, make close approach to two different gold atoms, stretching Sb-F to 1.99(2) and 1.94(2) Angstrom. In each case the Sb-F distances trans to these stretched Sb-F bonds are short,being 1.85(2) and 1.84(2) Angstrom, respectively. Magnetic susceptibility measurements show antiferromagnetic coupling with a susceptibility decrease below 13 K. Solvolysis of Au-II(SbF6)(2) in aHF is accompanied by disproportionation: 4Au(SbF6)(2)-->Au+Au3F8+8SbF(5)(solv). Fluorination, at similar to 20 degrees C, of the solution of Au(SbF6)(2), in SbF5 acidified aHF, precipitates red crystals of triclinic Au-II{SbF6}Au-2(II){(AuF4)-F-III}(2) with a(o)=5.2345(2) Angstrom, b(o)=8.1218(1) Angstrom, c(o)=10.5977(3) Angstrom, alpha=100.090(2)degrees, beta=100.327(2)degrees, gamma=104.877(2)degrees, V=416.63(2) Angstrom(3), space group , and Z=1. It is a simple paramagnet. The structure shows two different Au(II) environments, each approximately square-coordinated by F ligands, one being coordinated trans by an F ligand of each of two SbF6 and similarly by an F ligand from each of two (AuF4)-F-III species. The other Au(II) is approximately square-coordinated via bridging F ligands to four different (AuF4)-F-III species. Au-II{SbF6}Au-2(II){(AuF4)-F-III}(2) with KAuF4 in aHF yields Au3F8 free of metallic gold,the simple paramagnetism of which indicates the formulation Au-II{(AuF4)-F-III}(2). C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. NR 34 TC 38 Z9 38 U1 0 U2 3 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 FEB 5 PY 1997 VL 119 IS 5 BP 1020 EP 1026 DI 10.1021/ja9630654 PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA WG232 UT WOS:A1997WG23200021 ER PT J AU Wu, QY Gao, JM JosephMcCarthy, D Sigal, GB Bruce, JE Whitesides, GM Smith, RD AF Wu, QY Gao, JM JosephMcCarthy, D Sigal, GB Bruce, JE Whitesides, GM Smith, RD TI Carbonic anhydrase-inhibitor binding: From solution to the gas phase SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID IONIZATION MASS-SPECTROMETRY; CYTOCHROME-C; PROTEINS; CONFORMATION; DISSOCIATION; PEPTIDES; AFFINITY; IONS C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. HARVARD UNIV, DEPT CHEM & BIOL CHEM, CAMBRIDGE, MA 02138 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 28 TC 96 Z9 97 U1 0 U2 4 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 FEB 5 PY 1997 VL 119 IS 5 BP 1157 EP 1158 DI 10.1021/ja9630250 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WG232 UT WOS:A1997WG23200051 ER PT J AU Bar, G Rubin, S Parikh, AN Swanson, BI Zawodzinski, TA Whangbo, MH AF Bar, G Rubin, S Parikh, AN Swanson, BI Zawodzinski, TA Whangbo, MH TI Scanning force microscopy study of patterned monolayers of alkanethiols on gold. Importance of tip-sample contact area in interpreting force modulation and friction force microscopy images SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; THIN-FILMS; SPECTROSCOPY; SURFACES AB Several patterned monolayers of alkanethiols CH3(CH2)(n-1)SH on a polycrystalline Au substrate were prepared by using microcontact printing and solution deposition methods, and their surfaces were examined by IR spectroscopy, scanning force microscopy, lateral force microscopy (LFM), and force modulation microscopy(FMM). Our work Shows that LFM and FMM can detect differences in packing density of chemically identical molecules which are too small to be detected by IR, ellipsometry, and wetting measurements and suggests that the tip-sample contact area is an important parameter governing the contrasts of LFM and FMM images. Stiffness images obtained with FMM depend on changes in the Young's modulus of a sample surface as well as in the tip-sample contact area. As a result, a surface region of small modulus can have a large stiffness due to its large contact area. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. N CAROLINA STATE UNIV,DEPT CHEM,RALEIGH,NC 27695. RP Bar, G (reprint author), UNIV FREIBURG,FREIBURGER MAT FORSCHUNGSZENTRUM,STEFAN MEIER STR 21,D-79104 FREIBURG,GERMANY. RI PARIKH, ATUL/D-2243-2014 OI PARIKH, ATUL/0000-0002-5927-4968 NR 28 TC 71 Z9 71 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0743-7463 J9 LANGMUIR JI Langmuir PD FEB 5 PY 1997 VL 13 IS 3 BP 373 EP 377 DI 10.1021/la960935m PG 5 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WG364 UT WOS:A1997WG36400001 ER PT J AU Barenblatt, GI Chorin, AJ Prostokishin, VM AF Barenblatt, GI Chorin, AJ Prostokishin, VM TI Scaling laws for fully developed turbulent flow in pipes: Discussion of experimental data SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article AB We compare mean velocity profiles measured in turbulent pipe flows (and also in boundary layer flows) with the predictions of a recently proposed scaling law; in particular, we examine the results of the Princeton ''superpipe'' experiment and assess their range of validity. C1 UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RUSSIAN ACAD SCI,INST OCEANOL,MOSCOW 117218,RUSSIA. RP Barenblatt, GI (reprint author), UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720, USA. OI Prostokishin, Valeriy/0000-0001-6185-9642 NR 14 TC 32 Z9 33 U1 0 U2 12 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 FEB 4 PY 1997 VL 94 IS 3 BP 773 EP 776 DI 10.1073/pnas.94.3.773 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WG234 UT WOS:A1997WG23400002 PM 9023332 ER PT J AU Wu, M Rinchik, EM Wilkinson, E Johnson, DK AF Wu, M Rinchik, EM Wilkinson, E Johnson, DK TI Inherited somatic mosaicism caused by an intracisternal A particle insertion in the mouse tyrosinase gene SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID TRANSGENIC MICE; DIFFERENTIAL EXPRESSION; FUNCTIONAL-ANALYSIS; SEQUENCE-ANALYSIS; CDNA; KERATINOCYTES; TRANSCRIPTS; UPSTREAM; LOCUS AB A recessive, fully penetrant mutation (c(m1OR)) at the mouse albino locus that results in coat-color mottling has been characterized at the molecular level. Restriction mapping and DNA sequencing analyses provide evidence that mutants carry a 5.4-kb intracisternal A particle (IAP) element insertion upstream of the tyrosinase (Tyr) promoter. Northern blot analysis and reverse transcription-PCR results show that the tyrosinase gene is expressed at much lower levels in mutant than in wild-type mice. The mutant Tyr gene still retains the tissue-specific expression pattern, and the Tyr transcript is not initiated from the IAP long terminal repeat promoter. We propose that the IAP insertion isolates the promoter of the tyrosinase gene from upstream cia-acting regulatory elements, leading to a substantially decreased level of Tyr gene expression in mutants. C1 UNIV TENNESSEE,GRAD SCH BIOMED SCI,OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. SARAH LAWRENCE COLL,BRONXVILLE,NY 10708. UNIV TENNESSEE,COLL VET MED,DEPT PATHOL,KNOXVILLE,TN 37901. NR 28 TC 21 Z9 21 U1 0 U2 0 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 FEB 4 PY 1997 VL 94 IS 3 BP 890 EP 894 DI 10.1073/pnas.94.3.890 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WG234 UT WOS:A1997WG23400022 PM 9023352 ER PT J AU Mynatt, RL Miltenberger, RJ Klebig, ML Zemel, MB Wilkinson, JE Wilkison, WO Woychik, RP AF Mynatt, RL Miltenberger, RJ Klebig, ML Zemel, MB Wilkinson, JE Wilkison, WO Woychik, RP TI Combined effects of insulin treatment and adipose tissue-specific agouti expression on the development of obesity SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE transgenic mice; diabetes ID YELLOW A(VY)/ MICE; ECTOPIC EXPRESSION; TRANSGENIC MICE; HUMAN HOMOLOG; GENE; PROTEIN; IDENTIFICATION; MUTATION; ENHANCER; CLONING AB The agouti gene product is a secreted protein that acts in a paracrine manner to regulate coat color in mammals, Several dominant mutations at the agouti locus in mice cause the ectopic, ubiquitous expression of agouti, resulting in a condition similar to adult-onset obesity and non-insulin-dependent diabetes mellitus, The human agouti protein is 85% homologous to mouse agouti; however, unlike the mouse agouti gene, human agouti is normally expressed in adipose tissue, To address whether expression of agouti in human adipose tissue is physiologically relevant, transgenic mice were generated that express agouti in adipose tissue. Similar to most humans, these mice do not become obese or diabetic, However, we found that daily insulin injections significantly increased weight gain in the transgenic lines expressing agouti in adipose tissue, but not in nontransgenic mice, These results suggest that insulin triggers the onset of obesity and that agouti expression in adipose tissue potentiates this effect, Accordingly, the investigation of agouti's role in obesity and non-insulin-dependent diabetes mellitus in mice holds significant promise for understanding the pathophysiology of human obesity. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT NUTR,KNOXVILLE,TN 37996. UNIV TENNESSEE,COLL VET MED,DEPT PATHOL,KNOXVILLE,TN 37901. GLAXO WELLCOME INC,RES TRIANGLE PK,NC 27709. NR 33 TC 57 Z9 58 U1 0 U2 1 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 FEB 4 PY 1997 VL 94 IS 3 BP 919 EP 922 DI 10.1073/pnas.94.3.919 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WG234 UT WOS:A1997WG23400027 PM 9023357 ER PT J AU Peng, XG Wilson, TE Alivisatos, AP Schultz, PG AF Peng, XG Wilson, TE Alivisatos, AP Schultz, PG TI Synthesis and isolation of a homodimer of cadmium selenide nanocrystals SO ANGEWANDTE CHEMIE-INTERNATIONAL EDITION IN ENGLISH LA English DT Article DE cadmium; nanostructures; selenium ID QUANTUM DOTS; SEMICONDUCTOR; PARTICLES; CDS; CLUSTERS; MONOLAYERS; SURFACE; METAL; TIO2 C1 UNIV CALIF BERKELEY,HOWARD HUGHES MED INST,DEPT CHEM,ALBANY,CA 94710. LAWRENCE BERKELEY LAB,INST MOL DESIGN,BERKELEY,CA 94720. RI Alivisatos , Paul /N-8863-2015; peng, xiaogang/R-6184-2016 OI Alivisatos , Paul /0000-0001-6895-9048; peng, xiaogang/0000-0002-5606-8472 NR 28 TC 104 Z9 105 U1 3 U2 39 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 0570-0833 J9 ANGEW CHEM INT EDIT JI Angew. Chem.-Int. Edit. Engl. PD FEB 3 PY 1997 VL 36 IS 1-2 BP 145 EP 147 DI 10.1002/anie.199701451 PG 3 WC Chemistry, Multidisciplinary SC Chemistry GA WH998 UT WOS:A1997WH99800045 ER PT J AU Hull, JR Mulcahy, TM Labataille, JF AF Hull, JR Mulcahy, TM Labataille, JF TI Velocity dependence of rotational loss in Evershed-type superconducting bearings SO APPLIED PHYSICS LETTERS LA English DT Article ID ENERGY-STORAGE SYSTEMS; MAGNETIC BEARINGS; LOW-FRICTION; FLYWHEEL AB Results of free spin down in vacuum are reported for an Evershed-type superconducting bearing in which a permanent magnet (PM) ring is levitated over an array of high-temperature superconductors (HTSs) and under a similar PM ring in magnetic attraction. The velocity dependence of the rotational loss strongly suggests that the observed velocity-dependent losses are primarily due to eddy currents induced in the PM by inhomogeneity of the field produced by the magnetized HTS array. The results show that the Evershed-type bearing is capable of reducing these eddy-current losses to an extremely low level, so that at a maximum magnet rim velocity of 28 m/s, the fractional kinetic-energy loss per hour was 2.4 x 10(-4). Significant levitation heights are also possible, and at a 23 mm height, we measured a low-speed coefficient of friction of 3 x 10(-8). (C) 1997 American Institute of Physics. RP Hull, JR (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 11 TC 16 Z9 16 U1 3 U2 6 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 FEB 3 PY 1997 VL 70 IS 5 BP 655 EP 657 DI 10.1063/1.118324 PG 3 WC Physics, Applied SC Physics GA WF440 UT WOS:A1997WF44000041 ER PT J AU Hagberg, E Towner, IS Hardy, JC Koslowsky, VT Savard, G Sterbenz, S AF Hagberg, E Towner, IS Hardy, JC Koslowsky, VT Savard, G Sterbenz, S TI Beta decays of V-44 and Co-52 SO NUCLEAR PHYSICS A LA English DT Article DE RADIOACTIVITY V-44,V-44m, Co-52; measured E(gamma), I-gamma, T-1/2; deduced level energies, branching ratios, ft values; HPGe detectors, plastic scintillators; gamma beta beta and gamma gamma beta coincidences ID SHELL NUCLEI; TELLER; TRANSITIONS; MODEL AB We have studied the previously unknown beta(+) decay branches from V-44,V-44m and Co-52 to particle-bound states in Ti-44 and Fe-52, respectively. These intense branches populate a few states in the daughters from an excitation energy of about 1 MeV up to the isobaric analogue states at about 6 MeV. We have measured the first precise energy values for the latter states as well as the beta-branching ratios to all states in this excitation energy region. We have calculated the Pi decay of V-44,V-44m in the full fp shell model space as well as in a truncated space. Renormalized transition operators are constructed for the truncated space and tested against experimental data in V-44 and Co-52. In general there is good agreement between theory and experiment for the half-lives, level energies and beta branches, but not all the states found are reproduced by the calculations. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Hagberg, E (reprint author), AECL RES,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. NR 29 TC 15 Z9 15 U1 0 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 FEB 3 PY 1997 VL 613 IS 3 BP 183 EP 198 DI 10.1016/S0375-9474(96)00432-0 PG 16 WC Physics, Nuclear SC Physics GA WG143 UT WOS:A1997WG14300001 ER PT J AU Langanke, K Dean, DJ Koonin, SE Radha, PB AF Langanke, K Dean, DJ Koonin, SE Radha, PB TI Pairing correlations in N similar to Z pf-shell nuclei SO NUCLEAR PHYSICS A LA English DT Article ID MONTE-CARLO; MODEL; FE-54 AB We perform Shell Model Monte Carlo calculations to study pair correlations in the ground states of N = Z nuclei with masses A = 48-60. We find that T = 1, J(pi) = 0(+) proton-neutron correlations play an important, and even dominant role, in the ground states of odd-odd N = Z nuclei, in agreement with experiment. By studying pairing in the ground stales of Fe-52-58, we observe that the isovector proton-neutron correlations decrease rapidly with increasing neutron excess. In contrast, both the proton, and trivially the neutron correlations increase as neutrons are added, We also study the thermal properties and the temperature dependence of pair correlations for Mn-50 and Fe-52 as exemplars of odd-odd and even-even N = Z nuclei. While for Fe-52 results are similar to those obtained for other even-even nuclei in this mass range, the properties of Mn-50 at low temperatures are strongly influenced by isovector neutron-proton pairing. In coexistence with these isovector pair correlations, our calculations also indicate an excess of isoscalar proton-neutron pairing over the mean-field values. The isovector neutron-proton correlations rapidly decrease with temperatures and vanish for temperatures above T = 700 keV, while the isovector correlations among like-nucleons persist to higher temperatures. Related to the quenching of the isovector proton-neutron correlations, the average isospin decreases from 1, appropriate for the ground state, to 0 as the temperature increases. C1 AARHUS UNIV, INST PHYS & ASTRON, AARHUS, DENMARK. OAK RIDGE NATL LAB, DIV PHYS, OAK RIDGE, TN 37831 USA. RP Langanke, K (reprint author), CALTECH, WK KELLOGG RADIAT LAB, PASADENA, CA 91125 USA. OI Dean, David/0000-0002-5688-703X NR 27 TC 62 Z9 62 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 FEB 3 PY 1997 VL 613 IS 3 BP 253 EP 266 DI 10.1016/S0375-9474(96)00442-3 PG 14 WC Physics, Nuclear SC Physics GA WG143 UT WOS:A1997WG14300005 ER PT J AU Brodsky, SJ Hautmann, F Soper, DE AF Brodsky, SJ Hautmann, F Soper, DE TI Probing the QCD pomeron in e(+)e(-) collisions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HEAVY FLAVOR PRODUCTION; QUANTUM CHROMODYNAMICS; HADRON-COLLISIONS; QUARK PRODUCTION; BARE POMERON; BFKL POMERON; SINGULARITY AB The total cross section for scattering virtual photons at high energy is sensitive to pomeron physics. If the photons are sufficiently virtual, QCD perturbation theory applies, so that the reaction probes the short distance pomeron. We study this reaction for present and future e(+/-) e(-) colliders. C1 UNIV OREGON,INST THEORET SCI,EUGENE,OR 97403. RP Brodsky, SJ (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 31 TC 63 Z9 63 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 FEB 3 PY 1997 VL 78 IS 5 BP 803 EP 806 DI 10.1103/PhysRevLett.78.803 PG 4 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200013 ER PT J AU Signer, A Dixon, L AF Signer, A Dixon, L TI Electron-positron annihilation into four jets at next-to-leading order in alpha(s) SO PHYSICAL REVIEW LETTERS LA English DT Article ID 4-JET FINAL-STATES; E+ E ANNIHILATION; CROSS-SECTIONS; PERTURBATIVE QCD; Z(0) RESONANCE; 3-GLUON VERTEX; Z0 RESONANCE; AMPLITUDES; EVENTS; PREDICTIONS AB We calculate the rate for e(+) e(-) annihilation into four jets at next-to-leading order in perturbative QCD, but omitting terms that are suppressed by one or more powers of 1/N-c(2) where N-c is the number of colors. The O(alpha(s)(3)) corrections depend strongly on the jet resolution parameter y(cut) and on the clustering and recombination schemes, and they substantially improve the agreement between theory and data. RP STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94305 USA. NR 58 TC 59 Z9 59 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 3 PY 1997 VL 78 IS 5 BP 811 EP 814 DI 10.1103/PhysRevLett.78.811 PG 4 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200015 ER PT J AU Abe, K Akagi, T Anthony, PL Antonov, R Arnold, RG Averett, T Band, HR Bauer, JM Borel, H Bosted, PE Breton, V ButtonShafer, J Chen, JP Chupp, TE Clendenin, J Comptour, C Coulter, KP Court, G Crabb, D Daoudi, M Day, D Dietrich, FS Dunne, J Dutz, H Erbacher, R Fellbaum, J Feltham, A Fonvieille, H Frlez, E Garvey, D Gearhart, R Gomez, J Grenier, P Griffioen, KA Hoibraten, S Hughes, EW HydeWright, CE Johnson, JR Kawall, D Klein, A Kuhn, SE Kuriki, M Lindgren, R Liu, TJ LombardNelsen, RM Marroncle, J Maruyama, T Maruyama, XK McCarthy, J Meyer, W Meziani, ZE Minehart, R Mitchell, J Morgenstern, J Petratos, GG Pitthan, R Pocanic, D Prescott, C Prepost, R Raines, P Raue, BA Reyna, D Rijllart, A Roblin, Y Rochester, LS Rock, SE Rondon, OA Sick, I Smith, LC Smith, TB Spengos, M Staley, F Steiner, P StLorant, S Stuart, LM Suekane, F Szalata, ZM Tang, H Terrien, Y Usher, T Walz, D Wesselmann, F White, JL Witte, K Young, CC Youngman, B Yuta, H Zapalac, G Zihlmann, B Zimmelmann, D AF Abe, K Akagi, T Anthony, PL Antonov, R Arnold, RG Averett, T Band, HR Bauer, JM Borel, H Bosted, PE Breton, V ButtonShafer, J Chen, JP Chupp, TE Clendenin, J Comptour, C Coulter, KP Court, G Crabb, D Daoudi, M Day, D Dietrich, FS Dunne, J Dutz, H Erbacher, R Fellbaum, J Feltham, A Fonvieille, H Frlez, E Garvey, D Gearhart, R Gomez, J Grenier, P Griffioen, KA Hoibraten, S Hughes, EW HydeWright, CE Johnson, JR Kawall, D Klein, A Kuhn, SE Kuriki, M Lindgren, R Liu, TJ LombardNelsen, RM Marroncle, J Maruyama, T Maruyama, XK McCarthy, J Meyer, W Meziani, ZE Minehart, R Mitchell, J Morgenstern, J Petratos, GG Pitthan, R Pocanic, D Prescott, C Prepost, R Raines, P Raue, BA Reyna, D Rijllart, A Roblin, Y Rochester, LS Rock, SE Rondon, OA Sick, I Smith, LC Smith, TB Spengos, M Staley, F Steiner, P StLorant, S Stuart, LM Suekane, F Szalata, ZM Tang, H Terrien, Y Usher, T Walz, D Wesselmann, F White, JL Witte, K Young, CC Youngman, B Yuta, H Zapalac, G Zihlmann, B Zimmelmann, D TI Measurement of the proton and deuteron spin structure function g(1) in the resonance region SO PHYSICAL REVIEW LETTERS LA English DT Article ID DEEP-INELASTIC-SCATTERING; STRUCTURE-FUNCTION G1(X); SUM-RULE; PRECISION-MEASUREMENT; POLARIZED PROTONS; ASYMMETRY; Q(2)-DEPENDENCE; EVOLUTION AB We have measured the proton and deuteron spin structure functions g(1)(p) and g(1)(d) in the region of the nucleon resonances for W-2 < 5 GeV2 and Q(2) similar or equal to 0.5 and Q(2) similar or equal to 1.2 GeV2 by inelastically scattering 9.7 GeV polarized electrons off polarized (NH3)-N-15 and (ND3)-N-15 targets. We observe significant structure in g(1)(p) in the resonance region. We have used the present results, together with the deep-inelastic data at higher W-2, to extract Gamma(Q(2)) equivalent to integral(0)(1) g(1)(x,Q(2))dx. This is the first information on the low-Q(2) evolution of Gamma toward the Gerasimov-Drell-Hearn limit at Q(2) = 0. C1 UNIV BASEL,INST PHYS,CH-4056 BASEL,SWITZERLAND. UNIV CLERMONT FERRAND,CNRS,LPC,IN2P3,F-63170 CLERMONT FERRAN,FRANCE. TJNAF,NEWPORT NEWS,VA 23606. CTR ETUD SACLAY,DAPNIA,SERV PHYS NUCL,F-91191 GIF SUR YVETTE,FRANCE. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV MASSACHUSETTS,AMHERST,MA 01003. UNIV MICHIGAN,ANN ARBOR,MI 48109. USN,POSTGRAD SCH,MONTEREY,CA 93943. OLD DOMINION UNIV,NORFOLK,VA 23529. UNIV PENN,PHILADELPHIA,PA 19104. STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. STANFORD UNIV,STANFORD,CA 94309. TEMPLE UNIV,PHILADELPHIA,PA 19122. TOHOKU UNIV,SENDAI,MIYAGI 980,JAPAN. UNIV VIRGINIA,CHARLOTTESVILLE,VA 22901. COLL WILLIAM & MARY,WILLIAMSBURG,VA 23187. UNIV WISCONSIN,MADISON,WI 53706. UNIV LIVERPOOL,OLIVER LODGE LAB,LIVERPOOL L69 3BX,MERSEYSIDE,ENGLAND. UNIV BONN,D-5113 BONN,GERMANY. FFIYM,N-2007 KJELLER,NORWAY. FLORIDA INT UNIV,MIAMI,FL 33199. CERN,CH-1211 GENEVA 23,SWITZERLAND. RP Abe, K (reprint author), AMERICAN UNIV,WASHINGTON,DC 20016, USA. RI Averett, Todd/A-2969-2011; Rondon Aramayo, Oscar/B-5880-2013; Frlez, Emil/B-6487-2013; Day, Donal/C-5020-2015; OI Day, Donal/0000-0001-7126-8934; Wesselmann, Frank/0000-0001-7834-7977 NR 33 TC 85 Z9 85 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD FEB 3 PY 1997 VL 78 IS 5 BP 815 EP 819 DI 10.1103/PhysRevLett.78.815 PG 5 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200016 ER PT J AU Moretto, LG Tso, K Wozniak, GJ AF Moretto, LG Tso, K Wozniak, GJ TI Stable Coulomb bubbles? SO PHYSICAL REVIEW LETTERS LA English DT Article ID HOT NUCLEI; INSTABILITY; MULTIFRAGMENTATION AB Coulomb bubbles, though stable against monopole displacement, are unstable at least with respect to quadrupole and octupole distortions. We show that there exists a temperature at which the pressure of the vapor filling the bubble stabilizes all the radial modes. In extremely thin bubbles, the crispation modes become unstable due to the surface-surface interaction. RP Moretto, LG (reprint author), LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720, USA. NR 19 TC 20 Z9 20 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 FEB 3 PY 1997 VL 78 IS 5 BP 824 EP 827 DI 10.1103/PhysRevLett.78.824 PG 4 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200018 ER PT J AU Franceschetti, A Zunger, A AF Franceschetti, A Zunger, A TI Direct pseudopotential calculation of exciton Coulomb and exchange energies in semiconductor quantum dots SO PHYSICAL REVIEW LETTERS LA English DT Article ID POROUS SILICON; ELECTRONIC-STRUCTURE; CRYSTALLITES; CONFINEMENT; MICROCRYSTALS; TRANSITIONS; CLUSTERS; HOLES AB The effects of electron-hole interaction on the exciton energy of semiconductor quantum dots are calculated using pseudopotential wave functions. A comparison with the widely used, but never tested, effective-mass approximation (EMA) shows that the electron-hole Coulomb energy is significantly (similar to 40%) overestimated by the EMA, and that the scaling with the dot size R is sublinear in 1/R. The exchange splitting is much smaller than the Coulomb energy, and in the case of CdSe quantum dots shows significant deviations from the 1/R(3) scaling predicted by the EMA. RP Franceschetti, A (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 26 TC 186 Z9 187 U1 1 U2 21 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 FEB 3 PY 1997 VL 78 IS 5 BP 915 EP 918 DI 10.1103/PhysRevLett.78.915 PG 4 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200041 ER PT J AU Yanson, IK Fisun, VV Jansen, AGM Wyder, P Canfield, PC Cho, BK Tomy, CV Paul, DM AF Yanson, IK Fisun, VV Jansen, AGM Wyder, P Canfield, PC Cho, BK Tomy, CV Paul, DM TI Observation of electron-phonon interaction with soft phonons in superconducting RNi(2)B(2)C SO PHYSICAL REVIEW LETTERS LA English DT Article ID NI; LUNI2B2C AB The point-contact (PC) spectra of the electron-phonon interaction (EPI) in the superconducting RNi(2)B(2)C (R = Ho, Y) compounds reveal strong EPI with low-energy (4-9 meV) phonons, unlike the case of nonsuperconducting LaNi2B2C. The PC-EPI spectral functions for all three compounds are determined and lower limits for the EPI interaction parameter lambda estimated. Besides, an unusual suppression of the PC-EPI spectral intensity by the external magnetic field was observed for the superconducting compounds, unlike the nonsuperconducting one. C1 CNRS,F-38042 GRENOBLE 9,FRANCE. UKRAINIAN ACAD SCI,B VERKIN INST LOW TEMP PHYS & ENGN,UA-310164 KHARKOV,UKRAINE. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. UNIV WARWICK,DEPT PHYS,COVENTRY CV4 7AL,W MIDLANDS,ENGLAND. RP Yanson, IK (reprint author), MAX PLANCK INST FESTKORPERFORSCH,GRENOBLE HIGH MAGNET FIELD LAB,BP 166,F-38042 GRENOBLE 9,FRANCE. RI Canfield, Paul/H-2698-2014 NR 18 TC 26 Z9 26 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 FEB 3 PY 1997 VL 78 IS 5 BP 935 EP 938 DI 10.1103/PhysRevLett.78.935 PG 4 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200046 ER PT J AU Jaime, M Hardner, HT Salamon, MB Rubinstein, M Dorsey, P Emin, D AF Jaime, M Hardner, HT Salamon, MB Rubinstein, M Dorsey, P Emin, D TI Hall-effect sign anomaly and small-polaron conduction in (La1-xGdx)(0.67)Ca0.33MnO3 SO PHYSICAL REVIEW LETTERS LA English DT Article AB The Hall coefficient of Gd-doped La2/3Ca1/3MnO3 exhibits Arrhenius behavior over a temperature range from 2T(c) to 4T(c), with an activation energy very close to 2/3 that of the electrical conductivity. Although both the doping level and thermoelectric coefficient indicate holelike conduction, the Hall coefficient is electronlike. This unusual result provides strong evidence in favor of small-polaronic conduction in the paramagnetic regime of the manganites. C1 UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801. LOS ALAMOS NATL LAB,CTR MAT SCI,LOS ALAMOS,NM 87545. USN,RES LAB,WASHINGTON,DC 20375. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Jaime, M (reprint author), UNIV ILLINOIS,DEPT PHYS,1110 W GREEN ST,URBANA,IL 61801, USA. RI Jaime, Marcelo/F-3791-2015 OI Jaime, Marcelo/0000-0001-5360-5220 NR 17 TC 241 Z9 246 U1 4 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 FEB 3 PY 1997 VL 78 IS 5 BP 951 EP 954 DI 10.1103/PhysRevLett.78.951 PG 4 WC Physics, Multidisciplinary SC Physics GA WG702 UT WOS:A1997WG70200050 ER PT J AU Gronert, GA AF Gronert, GA TI Resistance to atracurium SO ACTA ANAESTHESIOLOGICA SCANDINAVICA LA English DT Letter RP Gronert, GA (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT ANESTHESIOL,TB 170,DAVIS,CA 95616, USA. NR 1 TC 1 Z9 1 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0001-5172 J9 ACTA ANAESTH SCAND JI Acta Anaesthesiol. Scand. PD FEB PY 1997 VL 41 IS 2 BP 327 EP 327 PG 1 WC Anesthesiology SC Anesthesiology GA WJ520 UT WOS:A1997WJ52000027 PM 9173775 ER PT J AU Trifunac, AD Sauer, MC Shkrob, IA Werst, DW AF Trifunac, AD Sauer, MC Shkrob, IA Werst, DW TI Radical cations in radiation chemistry of liquid hydrocarbons SO ACTA CHEMICA SCANDINAVICA LA English DT Article; Proceedings Paper CT 14th International Conference on Radical Ions CY JUL 01-05, 1996 CL UPPSALA, SWEDEN ID DETECTED MAGNETIC-RESONANCE; PULSE-RADIOLYSIS; TRANS-DECALIN; IRRADIATED CYCLOHEXANE; RATE CONSTANTS; POSITIVE-IONS; METHYLCYCLOHEXANE; SOLUTES; PAIRS AB The state of knowledge concerning radical cations in liquid alkanes is discussed with particular emphasis on those which exhibit high mobility. Uncertainty has existed in the interpretation of previous results with respect to the nature and reactivity of high mobility ions, especially for cyclohexane. Recent time-resolved studies on pulse radiolysis/transient absorption, photoconductivity, and magnetic resonance in these systems have led us to propose new mechanisms for the high mobility ions. In decalins, scavenging of these ions by solutes is a pseudo-first-order reaction, In cyclohexane, the behavior is more complex and is indicative of the involvement of two species, This bimodality is rationalized in terms of a dynamic equilibrium between two conformers of the solvent radical cation. Several experimental tests supporting these views include a recent study on two-color laser photoionization in cyclohexane. RP Trifunac, AD (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 25 TC 12 Z9 12 U1 0 U2 0 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0904-213X J9 ACTA CHEM SCAND JI Acta Chem. Scand. PD FEB PY 1997 VL 51 IS 2 BP 158 EP 166 DI 10.3891/acta.chem.scand.51-0158 PG 9 WC Biochemistry & Molecular Biology; Chemistry, Multidisciplinary SC Biochemistry & Molecular Biology; Chemistry GA WJ253 UT WOS:A1997WJ25300006 ER PT J AU Jensen, AF Larsen, FK Iversen, BB Petricek, V Schultz, T Gao, Y AF Jensen, AF Larsen, FK Iversen, BB Petricek, V Schultz, T Gao, Y TI Importance of true satellite reflections in the analysis of modulated, composite crystal structures .1. A new refinement of [M(2)Cu(2)O(3)](7+delta)[CuO2](10), M=Bi0.06Sr0.46Ca0.48 SO ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE LA English DT Article ID IMAGING PLATES; DIFFRACTION AB A new structural model for the composite crystal bismuth strontium calcium cuprate [M(2)Cu(2)O(3)](7+delta)[CuO2](10) With M=Bi0.06Sr0.46Ca0.48 and delta=0.03 has been determined, The structure is orthorhombic with a=11.380 (2), b=12.960 (4) Angstrom and incommensurate along c. Sublattice 1 of composition (CuO2)(4) has c(1)=2.7522 (4) Angstrom and sublattice 2 of composition (M(2)Cu(2)O(3))(4) has c(2)=3.9155 (5) Angstrom; superspace group F222(001 + gamma)001; modulation vector q(1)=gamma c(2)* With gamma=0.7029 (2). The structural analysis has been based on 603 main reflections, 428 first-order and 64 second-order satellite reflections. The final residual is R=0.0632 for all reflections, R=0.0614 for main reflections, R=0.0735 for first-order and R=0.1084 for second-order satellite reflections; lambda=0.6565 Angstrom, mu=19.4 mm(-1). The satellite reflections have been collected with X-ray synchrotron radiation. In this context, special experimental problems are discussed, It is shown that the true satellite reflections, which are the satellite reflections that are not also main reflections for one of the sublattices, are necessary in the least-squares refinement in order to avoid large correlations between displacive modulation amplitudes and thermal vibration amplitudes and thus to obtain a reasonable coordination chemistry. C1 AARHUS UNIV,DEPT CHEM,DK-8000 AARHUS C,DENMARK. ACAD SCI CZECH REPUBL,INST SOLID STATE PHYS,PRAGUE 16200 6,CZECH REPUBLIC. BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. RI Petricek, Vaclav/G-6868-2014 NR 28 TC 16 Z9 16 U1 0 U2 2 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0108-7681 J9 ACTA CRYSTALLOGR B JI Acta Crystallogr. Sect. B-Struct. Commun. PD FEB 1 PY 1997 VL 53 BP 113 EP 124 DI 10.1107/S0108768196011652 PN 1 PG 12 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WJ954 UT WOS:A1997WJ95400011 ER PT J AU Fu, CL Painter, GS AF Fu, CL Painter, GS TI Point defects and the binding energies of boron near defect sites in Ni3Al: A first-principles investigation SO ACTA MATERIALIA LA English DT Article ID INTERMETALLIC COMPOUND NI3AL; POSITRON-ANNIHILATION; DOPED NI3AL AB First-principles local-density-functional calculations have been used to investigate the equilibrium point defect structure and boron-defect interactions in Ni3Al. The dominant point defect types in off-stoichiometric Ni2Al are substitutional antisite defects on both sublattices. The boron binding energy is dependent on lattice coordination; it is strongest near vacancy sites with a nearest-neighbour nickel coordination number of about four (instead of six as in the defect-free interstitial site) and with no aluminium atom nearest-neighbours. This suggests that boron tends to segregate to ''open'' defect sites and to enhance cohesion through the formation of localized Ni-B covalent bonds. Comparison of the binding energies of boron and carbon in Ni3Al shows that boron has a stronger tendency to segregate to ''open'' sites than carbon. Copyright (C) 1997 Acta Metallurgica Inc. RP Fu, CL (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. NR 17 TC 63 Z9 69 U1 0 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD FEB PY 1997 VL 45 IS 2 BP 481 EP 488 DI 10.1016/S1359-6454(96)00208-X PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WF443 UT WOS:A1997WF44300006 ER PT J AU Song, SG Cole, JI Bruemmer, SM AF Song, SG Cole, JI Bruemmer, SM TI Formation of partial dislocations during intersection of glide dislocations with Frank loops in fcc lattices SO ACTA MATERIALIA LA English DT Article ID INSITU DEFORMATION AB Interactions of moving dislocations with Frank loops in quenched or irradiated materials can result in either coalescence or intersection reactions. The latter lead to the formation of partial dislocations associated with the resulting half loops. Alloy stacking fault energy (SFE) and specific deformation conditions are shown to control the reaction of the partial dislocations with the half loops. Based on this analysis, a partial dislocation mechanism is proposed that allows explanation of partial unfaulting, stacking fault extension, and twin formation, previously observed during plastic deformation of irradiated austenitic stainless steel. Copyright (C) 1997 Acta Metallurgica Inc. C1 WASHINGTON STATE UNIV, DEPT MECH & MAT ENGN, PULLMAN, WA 99163 USA. RP PACIFIC NW LAB, DEPT MAT SCI, RICHLAND, WA 99352 USA. OI Cole, James/0000-0003-1178-5846 NR 22 TC 19 Z9 19 U1 0 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 EI 1873-2453 J9 ACTA MATER JI Acta Mater. PD FEB PY 1997 VL 45 IS 2 BP 501 EP 511 DI 10.1016/S1359-6454(96)00206-6 PG 11 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WF443 UT WOS:A1997WF44300008 ER PT J AU McIntyre, PC Maggiore, CJ Nastasi, M AF McIntyre, PC Maggiore, CJ Nastasi, M TI Epitaxy of Pt thin films on (001)MgO .1. Interface energetics and misfit accommodation SO ACTA MATERIALIA LA English DT Article ID MAGNETIC-METAL STRUCTURES; SINGLE-CRYSTALS; PLATINUM FILMS; MGO; MGO(001); GROWTH; SUPERLATTICES AB Theoretical and experimental results on film/substrate interface energetics and misfit accommodation in Pt thin films on (001) MgO are reported. Two epitaxial orientations were observed in Pt films deposited on to (001) MgO substrates by electron beam evaporation: [110](001)Pt//[110](001) MgO and [110](111)Pt//[110](001) MgO. O-lattice calculations were used to predict film/substrate interface structures and relative interfacial energies for these two epitaxial Pt film orientations. The interfacial misfit dislocation structure was characterized by weak beam transmission electron microscopy. Good agreement was found among the calculated relative interface energies, reports in the literature, and the present experimental data. Copyright (C) 1997 Acta Metallurgica Inc. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. NR 29 TC 36 Z9 36 U1 3 U2 13 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD FEB PY 1997 VL 45 IS 2 BP 869 EP 878 DI 10.1016/S1359-6454(96)00182-6 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WF443 UT WOS:A1997WF44300041 ER PT J AU McIntyre, PC Maggiore, CJ Nastasi, M AF McIntyre, PC Maggiore, CJ Nastasi, M TI Epitaxy of Pt thin films on (001)MgO .2. Orientation evolution from nucleation through coalescence SO ACTA MATERIALIA LA English DT Article ID SINGLE-CRYSTALS; PLATINUM FILMS; MGO AB Orientation selection and microstructural evolution of thin platinum films deposited on to (001)MgO substrates are examined experimentally. The Pt/MgO system is an example of epitaxy in the absence of strong chemical interactions between film and substrate. Platinum films grow in the Volmer-Weber mode of epitaxy, and more than one epitaxial film orientation is possible on (001)MgO depending upon the deposition conditions. Experimental observations of orientation selection during film growth are explained based on film/substrate interface energy and film surface energy minimization. The results indicate that the final microstructure is controlled by grain boundary motion during and after coalescence of the island films. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. NR 15 TC 27 Z9 27 U1 4 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD FEB PY 1997 VL 45 IS 2 BP 879 EP 887 DI 10.1016/S1359-6454(96)00183-8 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA WF443 UT WOS:A1997WF44300042 ER PT J AU Lippert, T Yabe, A Wokaun, A AF Lippert, T Yabe, A Wokaun, A TI Laser ablation of doped polymer systems SO ADVANCED MATERIALS LA English DT Review ID POLY(METHYL METHACRYLATE) FILM; INFRARED 9.17-MU-M LASERS; PULSED NS ULTRAVIOLET; EXCIMER-LASER; 248 NM; TRIAZENE POLYMERS; GAS-DYNAMICS; HIGH-SPEED; HOT-SPOTS; 308 NM AB Laser ablation has become a widely recognized tool for materials processing. In the area of polymeric materials, applications of UV lasers for surface modification, microlithography, cutting, and boring have been explored. With the addition of dopants into the bulk, it has become possible to sensitize most known classes of polymers for UV laser ablation at any desired wavelength, including fluoropolymers. Important features of dopant-induced ablation are the reduction of threshold energy fluence required for ablation, and the enhancement of the etching rate by factors higher than ten. In the present review the investigated dopant/polymer systems are summarized and compared. Based on the available information, a general scheme including all relevant pathways is suggested, revealing that in each particular case the dominant mechanism depends on the specific system under study. C1 ETH ZURICH, CH-5232 VILLIGEN PSI, SWITZERLAND. PAUL SCHERRER INST, CH-5232 VILLIGEN PSI, SWITZERLAND. NATL INST MAT & CHEM RES, TSUKUBA, IBARAKI 305, JAPAN. LOS ALAMOS NATL LAB, DIV CHEM SCI & TECHNOL, LOS ALAMOS, NM 87545 USA. RI Lippert, Thomas/N-2423-2016 NR 114 TC 48 Z9 49 U1 3 U2 20 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY SN 0935-9648 EI 1521-4095 J9 ADV MATER JI Adv. Mater. PD FEB PY 1997 VL 9 IS 2 BP 105 EP 119 DI 10.1002/adma.19970090203 PG 15 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA WH746 UT WOS:A1997WH74600001 ER PT J AU Louck, JD AF Louck, JD TI Conway numbers and iteration theory SO ADVANCES IN APPLIED MATHEMATICS LA English DT Article AB Conway (''On Numbers and Games,'' Academic Press, New York, 1976) has given an inductive procedure for generating the real numbers that extends in a natural way to a new class of numbers called the surreals. The number 0 is defined at the first step in terms of a pair of empty sets. At step 1, the number 1 and its negative are generated, giving the set {1, 0, -1}; at step 2, the numbers 2, 1/2 and their negatives are generated, giving the set {2, 1, 1/2, 0, - 1/2, - 1, - 2}; at step 3, the numbers 3,3/2,3/4,1/4 and their negatives are generated, giving the set {3,2,3/2,1,3/4,1/2,1/4,0, - 1/4, - 1/2, -3/4, -1, -3/2, -2, -3}, etc. It is shown that these numbers are generated in one-to-one correspondence with certain sequences of positive and negative sequences of integers: At step 0, the sequence (0) is introduced; at step 1, the sequence (1) and its negative (-1) are generated, giving the set {(1), (0), (-1)}; at step 2, the sequences (2), (1, 1) and their negatives (-2),(-1, -1) are generated, giving the set {(2),(1),(1, 1),(0),(-1, -1), (-1), (-2)}; at step 3, the sequences (3), (2, 1), (1,1,1), (1, 2) and their negatives (-3), (-2, -1), (-1, -1, -1),(-1, -2) are generated, giving the set [(3), (2), (2,1), (1), (1,1,1), (1,1), (1,2), (0), (-1, -2), (-1, -1), (-1, -1, -1), (-1), (-2, -1), (-2), (-3}, etc. This generation of sequences in not ad hoc. The positive and negative sequences given here, and their generalizations, arise in iteration theory and in the theory of words associated with that theory. There is a natural order relation on these sequences that is one-to-one with the Conway numbers and which is rooted in the ordering of the inverse functions that arise in the description of the graph inverse to the nth iterate of certain classes of maps of an interval. A simple transformation of the points occurring in the cycles of the nth iterate of the trapezodal map of the interval [0,2] for n = 1,2,... give all the dyadic Conway numbers, in one-to-one correspondence with sequences, and the inclusion of infinite iterates yields all the reals. The implication of this result is that all such Conway numbers arise as fixed points of the trapezodal map, one-to-one with the sequences that label uniquely these fixed points. However, because of certain ''universality'' properties, the sequences themselves have application to and significance for other maps of the interval. The various aspects of iteration theory and its relation to the subset of real Conway numbers are discussed in some detail. The question of whether the surreal Conway numbers have application to iteration theory, hence, possibly to chaos, is left open. (C) 1997 Academic Press. RP Louck, JD (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 20 TC 2 Z9 2 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0196-8858 J9 ADV APPL MATH JI Adv. Appl. Math. PD FEB PY 1997 VL 18 IS 2 BP 181 EP 215 DI 10.1006/aama.1996.0507 PG 35 WC Mathematics, Applied SC Mathematics GA WH455 UT WOS:A1997WH45500004 ER PT J AU Brown, RA Rosenberg, NJ AF Brown, RA Rosenberg, NJ TI Sensitivity of crop yield and water use to change in a range of climatic factors and CO2 concentrations: A simulation study applying EPIC to the central USA SO AGRICULTURAL AND FOREST METEOROLOGY LA English DT Article ID ATMOSPHERIC CARBON-DIOXIDE; PRODUCTIVITY; RESPONSES; IMPACT; MODEL; WORLD; EVAPOTRANSPIRATION; AGRICULTURE; EROSION; GROWTH AB Crop production was simulated with the Erosion Productivity Impact Calculator (EPIC) for five representative farms in the Midwestern USA under a variety of climate scenarios. The impact on yields and water use in corn, soybean, winter wheat and sorghum was simulated over a range of temperature, precipitation, solar radiation, humidity and atmospheric carbon dioxide concentration ([CO2]) conditions. Stomatal resistance and leaf area index, plant physiological factors affected by changes in [CO2], were also varied in some of the simulations. Changes in each of these variables altered crop yields and water use. Increases in temperature accelerated the phenological development for all crops, shortened time to maturity, lowered yields, and decreased water use efficiency. Changes in precipitation and vapor pressure affected crop yield and water use by altering the degree of water stress experienced by the crop. For all crops, changes in precipitation and vapor pressure were positively correlated with changes in yield. Changes in solar radiation, which affect the amount of photosynthetically active radiation captured by the plant, were positively correlated with changes in crop yield. Increases in [CO2] and consequent increases in leaf area index and stomatal resistance increased crop yield and water use efficiency, lessening any negative impacts of changes in temperature, precipitation, vapor pressure and solar radiation and amplifying their positive effects. Interactions between different climate variables resulted in crop yield responses ranging from a multiplicative decrease when humidity and precipitation are decreased to a reduction in crop yield when solar radiation is increased and precipitation decreased. The demonstrated interactions of climatic factors indicate that future studies of climate change impacts should consider the full spectrum of climate variables and changes in atmospheric CO2 and not just temperature and precipitation. C1 PACIFIC NW LAB, WASHINGTON, DC 20024 USA. NR 29 TC 78 Z9 94 U1 4 U2 22 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1923 J9 AGR FOREST METEOROL JI Agric. For. Meteorol. PD FEB PY 1997 VL 83 IS 3-4 BP 171 EP 203 DI 10.1016/S0168-1923(96)02352-0 PG 33 WC Agronomy; Forestry; Meteorology & Atmospheric Sciences SC Agriculture; Forestry; Meteorology & Atmospheric Sciences GA WR996 UT WOS:A1997WR99600001 ER PT J AU Spencer, BB Counce, RM Egan, BZ AF Spencer, BB Counce, RM Egan, BZ TI Extraction of nitric acid from aqueous media with O phi D(iB)CMPO-n-dodecane SO AICHE JOURNAL LA English DT Article ID TRUEX PROCESS; ELECTROLYTES; ACTINIDES; SOLVENT AB A study of the extraction characteristics of nitric acid with octyl(phenyl)-N,N-diisobutylcarbcrmoylmethylphosphine oxide [O phi D(iB)CMPO or, simply, CMPO] was conducted. In the experimental program, CMPO was dissolved in n-dodecane to produce the organic extracting medium. The objectives of the project were to infer extraction stoichiometry and to estimate equilibrium constants for the extraction of nitric acid with the CMPO extractant. Experiments were performed over a limited range of concentrations to avoid conditions favoring formation of a third phase. Aqueous nitric acid concentrations were limited to 0.30 M at 25 degrees C, 1.0 M at 40 degrees C, and 3.0 M at 50 degrees C. The data indicate that CMPO extracts nitric acid with a 1:1 stoichiometry. The value of the equilibrium constant is estimated at 2.66 +/- 0.09 at 25 degrees C. The enthalpy of the extraction is estimated to be - 5.46 +/- 0.46 kcal/mol. C1 UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37916. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Spencer, BB (reprint author), OAK RIDGE NATL LAB,ROBOT & PROC SYST DIV,OAK RIDGE,TN 37831, USA. NR 31 TC 11 Z9 11 U1 1 U2 1 PU AMER INST CHEMICAL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0001-1541 J9 AICHE J JI AICHE J. PD FEB PY 1997 VL 43 IS 2 BP 555 EP 564 DI 10.1002/aic.690430228 PG 10 WC Engineering, Chemical SC Engineering GA WG129 UT WOS:A1997WG12900027 ER PT J AU Wagner, RG AF Wagner, RG TI Answer to question #5. Massive neutrinos SO AMERICAN JOURNAL OF PHYSICS LA English DT Letter RP Wagner, RG (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. NR 6 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 0002-9505 J9 AM J PHYS JI Am. J. Phys. PD FEB PY 1997 VL 65 IS 2 BP 105 EP 106 DI 10.1119/1.18502 PG 2 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA WE920 UT WOS:A1997WE92000003 ER PT J AU Stephenson, JL McLuckey, SA AF Stephenson, JL McLuckey, SA TI Counting basic sites in oligopeptides via gas-phase ion chemistry SO ANALYTICAL CHEMISTRY LA English DT Article ID MULTIPLY-CHARGED IONS; CYTOCHROME-C; PROTEIN IDENTIFICATION; SEQUENCE DATABASES; MOLECULE REACTIONS; MASS-SPECTROMETRY; PEPTIDES AB Cations derived from oligopeptides ranging from laminin fragment (5 residues) to beta-lactoglobulin (162 residues) have been subjected to gas-phase ion/molecule reactions with hydroiodic acid. The sum of the ion charge state and the maximum number of molecules of hydroiodic acid that attach to the ion is equal to the total number of lysines, arginines, histidines, and N-termini consisting of a primary amine for ions derived from all 21 oligopeptides studied, These results suggest that ion/molecule reactions can provide useful information regarding oligopeptide basic site number, which might be used as a criterion for searching protein data bases instead of, or in conjunction with, use of proteolytic digestion or gas-phase ion dissociation procedures. C1 OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RI Stephenson, James/A-9262-2009; McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 FU NIGMS NIH HHS [R01GM45372] NR 31 TC 47 Z9 47 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD FEB 1 PY 1997 VL 69 IS 3 BP 281 EP 285 DI 10.1021/ac961119m PG 5 WC Chemistry, Analytical SC Chemistry GA WF041 UT WOS:A1997WF04100004 PM 9030046 ER PT J AU Gittins, CM Castaldi, MJ Senkan, SM Rohlfing, EA AF Gittins, CM Castaldi, MJ Senkan, SM Rohlfing, EA TI Real-time quantitative analysis of combustion-generated polycyclic aromatic hydrocarbons by resonance-enhanced multiphoton ionization time-of-flight mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID DIFFUSION FLAME SIZES; GAS-CHROMATOGRAPHY; SUPERSONIC JET; SPECTRA; ANTHRACENE; PREDICTION; COMPLEXES AB We have combined resonance-enhanced multiphoton ionization (REMPI) time-of-flight mass spectrometry with on-line flame sampling to determine the centerline concentrations of naphthalene, fluorene, and anthracene in a pure methane + oxygen/argon (1:5) diffusion name, Naphthalene concentrations between 100 parts per billion by volume (ppbV) and 6 parts per million by volume (ppmV) and fluorene concentrations below 50 ppbV are determined using one-color REMPI on jet-cooled samples extracted from the name; anthracene concentrations in the 5-40 ppbV range are determined using two-color REMPI. The REMPI ion signals are converted to absolute concentrations in real time by performing gas-phase standard additions to the flame sample, Isomer-selective detection of larger polycyclic aromatic hydrocarbons, such as perylene and benzo[a]pyrene, is possible using the two-color REMPI approach. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. UNIV CALIF LOS ANGELES,DEPT CHEM ENGN,LOS ANGELES,CA 92004. NR 38 TC 62 Z9 62 U1 2 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD FEB 1 PY 1997 VL 69 IS 3 BP 286 EP 293 DI 10.1021/ac960969z PG 8 WC Chemistry, Analytical SC Chemistry GA WF041 UT WOS:A1997WF04100005 PM 21639183 ER PT J AU Hoogeveen, GW Jacobson, AR AF Hoogeveen, GW Jacobson, AR TI Improved analysis of plasmasphere motion using the VLA radio interferometer SO ANNALES GEOPHYSICAE-ATMOSPHERES HYDROSPHERES AND SPACE SCIENCES LA English DT Article ID ELECTRIC-FIELDS; LARGE ARRAY; RADIOTELESCOPE; IRREGULARITIES; DRIFTS AB Observations using the very large array (VLA) radio interferometer during the past five years have enabled the discovery of a new type of plasmasphere disturbance, the magnetic eastward-directed wave. Previous work indicated these disturbances were likely frozen to the geomagnetic field as determined from their azimuth distributions. This work provides a method to explain more accurately the azimuth distribution, thereby allowing the calculation of the disturbances' location in the plasmasphere independently of the measured velocity. The measurable velocity due to corotation is calculated and subtracted from the measured trace velocity. This difference, or deviation from corotation, is attributed to electrodynamic convection; the measurement of plasmaspheric convection may lead to the eventual monitoring of mid-latitude electric fields. Disturbances are seen convecting predominantly westward, with the fastest having angular velocities greater than the anticorotating VLA line of sight. The direction of convection and conditions of observations indicate that the disturbances are likely the same phenomenon seen by the Los Alamos satellite beacon array. RP Hoogeveen, GW (reprint author), LOS ALAMOS NATL LAB,SPACE & ATMOSPHER SCI GRP,MAIL ST D466,LOS ALAMOS,NM 87545, USA. NR 15 TC 13 Z9 13 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0992-7689 J9 ANN GEOPHYS-ATM HYDR JI Ann. Geophys.-Atmos. Hydrospheres Space Sci. PD FEB PY 1997 VL 15 IS 2 BP 236 EP 245 DI 10.1007/s005850050437 PG 10 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA WJ812 UT WOS:A1997WJ81200010 ER PT J AU Spriggs, GD Busch, RD Williams, JG AF Spriggs, GD Busch, RD Williams, JG TI Two-region kinetic model for reflected reactors SO ANNALS OF NUCLEAR ENERGY LA English DT Article AB Deflected reactors constitute one of the most important classes of nuclear reactors. Yet, experimental data clearly shows that the kinetic behavior of some types of reflected systems cannot be adequately characterized using the standard point kinetic model. In this work, a two-region, nodal kinetic model for reflected systems is developed that appears to explain the anomalous behavior of these systems in terms of integral parameters that are both measurable and calculable. The model is based on previous work by Avery and Cohn. We augment the Avery-Cohn model with the introduction of simple probability relationships essential to calculating the coupling parameters between the core and the reflector. Using these probability relationships, we then derive the definition of the effective multiplication factor k(eff), in terms of the multiplication factor of the core region, k(e), and the reflector return fraction, f. We also derive the reflected-core inhour equation and introduce expressions to calculate the neutron lifetimes characterizing the system's static and dynamic behavior. The model is then tested using Rossi-alpha data from the University of New Mexico's AGN-201 reactor. Copyright (C) 1996 Elsevier Science Ltd. C1 UNIV NEW MEXICO,DEPT CHEM & NUCL ENGN,ALBUQUERQUE,NM 87131. UNIV ARIZONA,DEPT NUCL & ENERGY ENGN,TUCSON,AZ 85721. RP Spriggs, GD (reprint author), LOS ALAMOS NATL LAB,POB 1663,MS B226,LOS ALAMOS,NM 87545, USA. NR 64 TC 29 Z9 29 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0306-4549 J9 ANN NUCL ENERGY JI Ann. Nucl. Energy PD FEB PY 1997 VL 24 IS 3 BP 205 EP 250 DI 10.1016/0306-4549(96)00062-X PG 46 WC Nuclear Science & Technology SC Nuclear Science & Technology GA VU051 UT WOS:A1997VU05100005 ER PT J AU Mourant, JR Fuselier, T Boyer, J Johnson, TM Bigio, IJ AF Mourant, JR Fuselier, T Boyer, J Johnson, TM Bigio, IJ TI Predictions and measurements of scattering and absorption over broad wavelength ranges in tissue phantoms SO APPLIED OPTICS LA English DT Article ID LASER-INDUCED FLUORESCENCE; PHOTON-DENSITY WAVES; LIGHT-SCATTERING; OPTICAL-PROPERTIES; MEDIA; SPECTROSCOPY; CELLS; PROPAGATION; DIAGNOSIS; SPECTRA AB Predictions from Mie theory regarding the wavelength dependence of scattering in tissue from the near UV to the near IR are discussed and compared with experiments on tissue phantoms. For large fiber separations it is shown that rapid, simultaneous measurements of the elastic scatter signal for several fiber separations can yield the absorption coefficient and reduced scattering coefficient. With this information, the size of the scattering particles can be estimated, and this is done for Intralipid. Measurements made at smaller source detector separations support Mie theory calculations, demonstrating that the sensitivity of elastic scatter measurements to morphological features, such as scatterer size, is enhanced when the distance between the source and detector fibers is small. (C) 1997 Optical Society of America RP Mourant, JR (reprint author), LOS ALAMOS NATL LAB,BIOSCI & BIOTECHNOL GRP CST4,MS E535,LOS ALAMOS,NM 87545, USA. OI Bigio, Irving/0000-0003-4168-1466 NR 33 TC 334 Z9 340 U1 5 U2 32 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD FEB 1 PY 1997 VL 36 IS 4 BP 949 EP 957 DI 10.1364/AO.36.000949 PG 9 WC Optics SC Optics GA WF061 UT WOS:A1997WF06100027 PM 18250760 ER PT J AU Gauck, H Gfroerer, TH Renn, MJ Cornell, EA Bertness, KA AF Gauck, H Gfroerer, TH Renn, MJ Cornell, EA Bertness, KA TI External radiative quantum efficiency of 96% from a GaAs/GaInP heterostructure SO APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING LA English DT Article AB GaAs/GaInP double heterostructures are index matched with ZnSe hemispheres to increase the coupling of photoluminescence out of the device. We measure external quantum efficiencies as large as 96% at room temperature using a bolometric calibration technique. When the carriers are optically injected near the bandgap energy, the luminescence is blueshifted by up to 1.4 kT. In this case, external efficiencies exceeding 97.5% would yield optical refrigeration in the solid state. C1 UNIV COLORADO,JOINT INST LAB ASTROPHYS,BOULDER,CO 80309. NATL INST STAND & TECHNOL,BOULDER,CO 80309. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 9 TC 92 Z9 94 U1 1 U2 8 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0947-8396 J9 APPL PHYS A-MATER JI Appl. Phys. A-Mater. Sci. Process. PD FEB PY 1997 VL 64 IS 2 BP 143 EP 147 DI 10.1007/s003390050455 PG 5 WC Materials Science, Multidisciplinary; Physics, Applied SC Materials Science; Physics GA WJ518 UT WOS:A1997WJ51800004 ER PT J AU Reeder, PL Stromswold, DC Brodzinski, RL Reeves, JH Wilson, WE AF Reeder, PL Stromswold, DC Brodzinski, RL Reeves, JH Wilson, WE TI Moisture measurement for radioactive wastes using neutron activation of copper SO APPLIED RADIATION AND ISOTOPES LA English DT Article ID GAUGE AB Laboratory tests have demonstrated the use of neutron activation of copper to measure the moisture in radioactive wastes. Neutrons from a source scatter and return to activate the copper in the probe, the amount of activation varying with moisture content. A low-background spectrometer counts the gamma rays from activated Cu-61. The calibration of count rate vs moisture was measured with waste simulants of three moisture contents (15%. 20% and 25% by weight). The technique can also measure the neutron flux from spontaneous fission of actinide nuclides and neutrons from (alpha, n) reactions on light elements. Copyright (C) 1997 Elsevier Science Ltd RP Reeder, PL (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 13 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0969-8043 J9 APPL RADIAT ISOTOPES JI Appl. Radiat. Isot. PD FEB PY 1997 VL 48 IS 2 BP 247 EP 256 DI 10.1016/S0969-8043(96)00152-2 PG 10 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Chemistry; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WF439 UT WOS:A1997WF43900014 ER PT J AU Fisher, WG Wachter, EA Armas, M Seaton, C AF Fisher, WG Wachter, EA Armas, M Seaton, C TI Titanium:sapphire laser as an excitation source in two-photon spectroscopy SO APPLIED SPECTROSCOPY LA English DT Article DE two-photon excitation; laser-induced fluorescence; LIF; titanium:sapphire laser; multimode power correction; second-order coherence ID 2-PHOTON EXCITED FLUORESCENCE; 2ND HARMONIC DETECTION; MODE-LOCKING; ABSORPTION AB The passively mode-locked titanium:sapphire laser provides new opportunities for acquiring two-photon spectral data in the near-infrared, a region not commonly accessible to synchronously pumped dye lasers. This source generates pulses with peak powers near 100 kW at average powers over 1 W and is capable of yielding two-photon signals roughly two orders of magnitude larger than is possible with synchronously pumped dye lasers. However, the multimode output of this laser exhibits significant temporal and spectral pulse profile variations as the laser wavelength is tuned, As a consequence, peak powers of the titanium:sapphire laser can vary independently from average power across the tuning range. This wavelength dependence, coupled with the quadratic dependence of the two-photon signal upon the instantaneous power of the laser, precludes simple average power correction of nonlinear spectral band shapes. Here, we investigate the key properties of the titanium:sapphire laser as an excitation source for two-photon spectroscopy. We also identify a chemical reference suitable for obtaining source-corrected excitation spectra in the near-infrared using a double-beam, ratiometric approach; this is based on a source-independent two-photon excitation spectrum for the laser dye coumarin-480 that has been obtained with a single-frequency titanium:sapphire laser. From these data, correction factors are generated for correction of multimode source data. C1 COHERENT LASER GRP,SANTA CLARA,CA 95054. RP Fisher, WG (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 41 TC 25 Z9 25 U1 1 U2 4 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD FEB PY 1997 VL 51 IS 2 BP 218 EP 226 DI 10.1366/0003702971939910 PG 9 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA WM533 UT WOS:A1997WM53300011 ER PT J AU Zhang, LZ Franke, JE Niemczyk, TM Haaland, DM AF Zhang, LZ Franke, JE Niemczyk, TM Haaland, DM TI Optimized external IR reflection spectroscopy for quantitative determination of borophosphosilicate glass parameters SO APPLIED SPECTROSCOPY LA English DT Article DE IR reflection; multivariate calibration; partial least-squares; borophosphosilicate glass ID INFRARED-SPECTROSCOPY; FILMS; SILICON; SPECTRA; WAFERS; MODELS AB Infrared (IR) external reflection spectroscopy has been optimized for the quantitative determination of composition and film thickness of borophosphosilicate glass (BPSG) deposited on silicon wafer substrates. The precision of the partial Least-squares calibrations for boron and phosphorus contents and thin-film thickness were measured as the cross-validated standard error of prediction statistic. The results showed that BPSG IR reflection spectra collected over a wide range of incident IR radiation angles (15 degrees, 25 degrees, 45 degrees, and 60 degrees) can be used for the simultaneous quantification of these three BPSG parameters. When high angles of incidence were employed, the measurement was found to be more sensitive to small errors in the angle of incidence. The polarization state of the incident IR radiation did not noticeably affect the prediction of the three calibrated BPSG parameters. The results achieved in this study provide guidelines for at-line process monitoring and quality control of BPSG thin films used in the fabrication of microelectronic devices. C1 UNIV NEW MEXICO,DEPT CHEM,ALBUQUERQUE,NM 87131. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 18 TC 6 Z9 6 U1 0 U2 1 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD FEB PY 1997 VL 51 IS 2 BP 259 EP 264 DI 10.1366/0003702971940161 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA WM533 UT WOS:A1997WM53300017 ER PT J AU Lippert, T Stoutland, PO AF Lippert, T Stoutland, PO TI Laser-material interactions probed with picosecond infrared spectroscopy SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT Proceedings of Symposium H on Laser Processing of Surfaces and Thin Films of the 1996 E-MRS Spring Conference CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc ID WOLFF-REARRANGEMENT; DYNAMICS AB Picosecond infrared spectroscopy in the mid-IR has been applied to the study of laser-material interactions on an ultrafast time scale. We excite the sample with one pulse at 1064 or 266 nm and probe some time later in the mid IR (2900-1400 cm(-1)). We study photochemical reactions by exciting the sample directly in the W. Alternatively, we initiate thermal reactions by exciting a 'heater' dye at 1.064 mu m, which quickly converts the photon energy into heat. The potential of this technique to study reactions in the solid state was demonstrated for the photochemically induced (266 nm) Wolff rearrangement in a polymer matrix, This reaction is the basis of most positive photoresists. We were able to assign the key intermediate (ketene) in real time at room temperature for the first time. Thermal initiation also resulted in Wolff rearrangement. The position, amplitude and width of the product bands changed, probably due to additional side reactions and temperature effects. RP Lippert, T (reprint author), LOS ALAMOS NATL LAB, MS J585, LOS ALAMOS, NM 87545 USA. RI Lippert, Thomas/N-2423-2016 NR 16 TC 17 Z9 17 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD FEB PY 1997 VL 109 BP 43 EP 47 DI 10.1016/S0169-4332(96)00617-4 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA WK227 UT WOS:A1997WK22700009 ER PT J AU Lippert, T Nakamura, T Niino, H Yabe, A AF Lippert, T Nakamura, T Niino, H Yabe, A TI Laser induced chemical and physical modifications of polymer films: Dependence on the irradiation wavelength SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT Proceedings of Symposium H on Laser Processing of Surfaces and Thin Films of the 1996 E-MRS Spring Conference CY JUN 04-07, 1996 CL STRASBOURG, FRANCE SP European Mat Res Soc ID EXCIMER-LASER; TRIAZENE POLYMERS; ABLATION; PHOTOABLATION AB Polymers with photolabile groups absorbing in the mid UV (around 300 nm) were irradiated with excimer-lasers (248 and 308 nm). Irradiation with 248 nm (KrF laser) corresponds to an excitation of the photostable phenyl system whereas the XeCl laser (308 nm) excites the labile triazeno groups (-N=N-N drop). Thin polymer films (0.1-3 mu m) were coated onto quartz or glass and irradiated below and above the threshold of ablation. The films were subsequently analyzed with various surface analysis techniques. Below the threshold of ablation the main feature at both irradiation wavelengths was the reduction of the absorption maximum at about 330 nm and an increase of the surface oxygen content (X-ray photoelectron spectroscopy) and therefore the surface polarity (contact angle). The surface remained smooth with no detectable micro-structures (scanning electron microscopy). Above the ablation threshold the absorbance at 330 nm decreased dramatically and the color of the film changed. For 248 nm irradiation the surface was darkened and a carbonization (XPS) with microstructures (SEM) was detected. The surface became non-polar in agreement with surface carbonization. In the case of 308 nm irradiation the surface remained smooth and no change of the chemical composition or surface polarity was detected, suggesting a photochemically induced layer by layer ablation process. C1 NATL INST MAT & CHEM RES, TSUKUBA, IBARAKI 305, JAPAN. RP Lippert, T (reprint author), LOS ALAMOS NATL LAB, MS J 585, LOS ALAMOS, NM 87545 USA. RI Nakamura, Takako/E-7932-2015; Lippert, Thomas/N-2423-2016 NR 14 TC 25 Z9 25 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD FEB PY 1997 VL 109 BP 227 EP 231 DI 10.1016/S0169-4332(96)00663-0 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA WK227 UT WOS:A1997WK22700042 ER PT J AU Cohen, RL Guhathakurta, P Yanny, B Schneider, DP Bahcall, JN AF Cohen, RL Guhathakurta, P Yanny, B Schneider, DP Bahcall, JN TI Globular cluster photometry with the Hubble Space Telescope .6. WF/PC-I observations of the stellar populations in the core of M13 (NGC 6205) SO ASTRONOMICAL JOURNAL LA English DT Article ID HORIZONTAL-BRANCH STARS; MAIN-SEQUENCE PHOTOMETRY; COLOR-MAGNITUDE DIAGRAMS; FIELD PLANETARY CAMERA; HST OBSERVATIONS; BLUE STRAGGLERS; MASS FUNCTION; M3; M92; LUMINOSITY AB We study the dense core of the globular cluster Messier 13 (NGC 6205) using pre-refurbishment Planetary Camera-I images obtained with the Hubble Space Telescope, Short exposures (60 s) through the F555W and F785LP filters (similar to Johnson V and I, respectively) have been used to obtain V and I photometry of 2877 stars brighter than V similar to 20 in a 1.25 arcmin(2) region of the cluster including its core and extending out to r similar to 66 '' (2.3 pc) from its center. The sample is complete to V similar or equal to 18.3 (the main sequence turnoff) and the 1 sigma photometric error is about 0.1 mag. We find 15 blue straggler star candidates and 10 other possible blue stragglers in this region of M13. Their specific frequency is in the range F-BSS = 0.04-0.07, comparable to what is observed near the centers of other dense clusters. A comparison between M13's observed V band stellar luminosity function and a theoretical model (Bergbusch & Vandenberg, 1992, ApJS, 81, 163) for the luminosity function of an old, metal-poor cluster shows that the model predicts too few of the brightest red giants (V similar to 12.5-15) by a factor of two relative to subgiants/turnoff stars (>6 sigma effect). The radial distributions of red giants, blue stragglers, and subgiants are consistent with one another, and are well fit by a King profile of core radius r(core) = 38 '' + 6 '' (90% confidence limits) or 1.3 pc. Stars in the blue horizontal branch of M13, however, appear to be centrally depleted relative to other stellar types. We combine data from three dense ''King model clusters,'' M13, M3, and 47 Tuc, and two post core collapse clusters, M30 and M15, and compare the distributions of various stellar types as a function of (r/r(half light)) and (r/r(core)). The horizontal branch stars in the combined sample appear to be centrally depleted relative to the giants (97% significance)-this depletion is only a 1 sigma-2 sigma effect in each of the clusters taken individually. The blue stragglers in the combined sample are centrally concentrated relative to the giants. (C) 1997 American Astronomical Society. C1 FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. PENN STATE UNIV,DEPT ASTRON & ASTROPHYS,UNIVERSITY PK,PA 16802. INST ADV STUDY,PRINCETON,NJ 08540. RP Cohen, RL (reprint author), UNIV CALIF SANTA CRUZ,UNIV CALIF OBSERV,LICK OBSERV,SANTA CRUZ,CA 95064, USA. NR 44 TC 18 Z9 18 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1997 VL 113 IS 2 BP 669 EP 681 DI 10.1086/118285 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WE934 UT WOS:A1997WE93400018 ER PT J AU Zuckerman, B Becklin, EE Macintosh, BA Bida, T AF Zuckerman, B Becklin, EE Macintosh, BA Bida, T TI A companion to the white dwarf G261-43 SO ASTRONOMICAL JOURNAL LA English DT Article ID BROWN DWARF; STARS AB Infrared images at wavelengths between 1 and 2.5 mu m reveal that the nearby 16 000 K white dwarf, G261-43, has a companion located 1.4 arcsec (similar to 30 AU) away. The companion is, apparently, another white dwarf of temperature similar to 5000 K. We estimate a difference of about 4 mag at V band. This suggests that infrared imaging with good image quality can be a useful method for discovering double white dwarfs where the components have significantly different temperatures and small separations. (C) 1997 American Astronomical Society. C1 LAWRENCE LIVERMORE NATL LAB,INST GEOPHYS & PLANETARY PHYS,LIVERMORE,CA 94550. CALIF ASSOC RES ASTRON,KAMUELA,HI 96743. RP Zuckerman, B (reprint author), UNIV CALIF LOS ANGELES,DEPT PHYS & ASTRON,LOS ANGELES,CA 90095, USA. NR 13 TC 5 Z9 5 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0004-6256 J9 ASTRON J JI Astron. J. PD FEB PY 1997 VL 113 IS 2 BP 764 EP 766 DI 10.1086/118296 PG 3 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WE934 UT WOS:A1997WE93400029 ER PT J AU Gurvits, LI Schilizzi, RT Miley, GK Peck, A Bremer, MN Rottgering, H vanBreugel, W AF Gurvits, LI Schilizzi, RT Miley, GK Peck, A Bremer, MN Rottgering, H vanBreugel, W TI A compact radio component in 4C 41.17 at z=3.8: A massive clump in a forming galaxy? SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies:individual:4C 41.17; radio continuum:galaxies; galaxies:jets; galaxies:star clusters ID REDSHIFT AB We present the results of a study of the centiarcsecond radio structure at wavelength of 18 cm in the high-redshift galaxy associated with the radio source 4C 41.17 (z = 3.8). We have detected a component of size not more than 15 mas (similar or equal to 65 pc, H-o = 75 km s(-1) Mpc(-1), q(o) = 0.5) at a distance of similar or equal to 2.9 kpc from the nucleus of the galaxy which accounts for similar to 30% of the flux density of the previously known unresolved VLA component. We speculate that the radio component is associated with a clump in the interstellar medium. The estimate of its mass, 1.5 x 10(8) M., is consistent with those of subgalactic structures preceding formation of globular clusters in the early stages of the evolution of galaxies. C1 PN LEBEDEV PHYS INST, CTR ASTRO SPACE, MOSCOW 117924, RUSSIA. LEIDEN OBSERV, NL-2300 RA LEIDEN, NETHERLANDS. LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, LIVERMORE, CA 94550 USA. NEW MEXICO INST MIN & TECHNOL, DEPT PHYS, SOCORRO, NM 87801 USA. RP Gurvits, LI (reprint author), JOINT INST VLBI EUROPE, POB 2, NL-7990 AA DWINGELOO, NETHERLANDS. NR 18 TC 8 Z9 8 U1 0 U2 0 PU EDP SCIENCES S A PI LES ULIS CEDEX A PA 17, AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE SN 0004-6361 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD FEB PY 1997 VL 318 IS 1 BP 11 EP 14 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WH394 UT WOS:A1997WH39400011 ER PT J AU Ambrosio, M Antolini, R Auriemma, G Baker, R Baldini, A Barbarino, GC Barish, BC Battistoni, G Bellotti, R Bemporad, C Bernardini, P Bilokon, H Bisi, V Bloise, C Bosio, T Bower, C Bussino, S Cafagna, R Calicchio, M Campana, D Carboni, M Castellano, M Cecchini, S Cei, F Chiarella, V Corona, A Coutu, S DeCataldo, G Dekhissi, H DeMarzo, C DeMitri, I DeVincenzi, M DiCredico, A Erriquez, O Fantini, R Favuzzi, C Forti, C Fusco, P Giacomelli, G Giannini, G Giglietto, N Goretti, M Grassi, M Green, P Grillo, A Guarino, F Guarnaccia, P Gustavino, C Habig, A Hanson, K Hawthorne, A Heinz, R Jong, JT Iarocci, E Katsavounidis, E Kearns, E Kyriazopoulou, S Lamanna, E Lane, C Levin, DS Lipari, P Liu, G Liu, R Longley, NP Longo, MJ Ludlam, G Mancarella, G Mandrioli, G MargiottaNeri, A Marini, A Martello, D MarzariChiesa, A Mazziotta, MN Michael, DG Mikheyev, S Miller, L Monacelli, P Montaruli, T Monteno, M Mufson, S Musser, J Nicolo, D Nolty, R Okada, C Orth, C Osteria, G Palamara, O Parlati, S Patera, V Patrizii, L Pazzi, R Peck, CW Petrera, S Pignatano, ND Pistilli, P Popa, V Raino, A Reynoldson, J Ronga, F Rubizzo, U Sanzgiri, A Sartogo, F Satriano, C Satta, L Scapparone, E Scholberg, K Sciubba, A SerraLugaresi, P Severi, M Sinev, V Sitta, M Spinelli, P Spinetti, M Spurio, M Steinberg, R Stone, JL Sulak, LR Surdo, A Tarle, G Togo, V Valente, V Walter, CW Webb, R AF Ambrosio, M Antolini, R Auriemma, G Baker, R Baldini, A Barbarino, GC Barish, BC Battistoni, G Bellotti, R Bemporad, C Bernardini, P Bilokon, H Bisi, V Bloise, C Bosio, T Bower, C Bussino, S Cafagna, R Calicchio, M Campana, D Carboni, M Castellano, M Cecchini, S Cei, F Chiarella, V Corona, A Coutu, S DeCataldo, G Dekhissi, H DeMarzo, C DeMitri, I DeVincenzi, M DiCredico, A Erriquez, O Fantini, R Favuzzi, C Forti, C Fusco, P Giacomelli, G Giannini, G Giglietto, N Goretti, M Grassi, M Green, P Grillo, A Guarino, F Guarnaccia, P Gustavino, C Habig, A Hanson, K Hawthorne, A Heinz, R Jong, JT Iarocci, E Katsavounidis, E Kearns, E Kyriazopoulou, S Lamanna, E Lane, C Levin, DS Lipari, P Liu, G Liu, R Longley, NP Longo, MJ Ludlam, G Mancarella, G Mandrioli, G MargiottaNeri, A Marini, A Martello, D MarzariChiesa, A Mazziotta, MN Michael, DG Mikheyev, S Miller, L Monacelli, P Montaruli, T Monteno, M Mufson, S Musser, J Nicolo, D Nolty, R Okada, C Orth, C Osteria, G Palamara, O Parlati, S Patera, V Patrizii, L Pazzi, R Peck, CW Petrera, S Pignatano, ND Pistilli, P Popa, V Raino, A Reynoldson, J Ronga, F Rubizzo, U Sanzgiri, A Sartogo, F Satriano, C Satta, L Scapparone, E Scholberg, K Sciubba, A SerraLugaresi, P Severi, M Sinev, V Sitta, M Spinelli, P Spinetti, M Spurio, M Steinberg, R Stone, JL Sulak, LR Surdo, A Tarle, G Togo, V Valente, V Walter, CW Webb, R TI The performance of MACRO liquid scintillator in the search for magnetic monopoles with 10(-3)PYRENE DIOL EPOXIDE; DEOXYADENOSINE N-6-AMINO GROUP; 2 INTERCHANGEABLE CONFORMATIONS; SNAKE-VENOM PHOSPHODIESTERASE; ESCHERICHIA-COLI PLASMID; DG MISMATCH OPPOSITE; IN-VITRO REPLICATION; N-RAS CODON-61; FEMALE CD RATS; FJORD-REGION C1 NYU, DEPT BIOL, NEW YORK, NY 10003 USA. MEM SLOAN KETTERING CANC CTR, CELLULAR BIOCHEM & BIOPHYS PROGRAM, NEW YORK, NY 10021 USA. OAK RIDGE NATL LAB, HLTH SCI RES DIV, OAK RIDGE, TN 37831 USA. AMER HLTH FDN, VALHALLA, NY 10595 USA. RP Geacintov, NE (reprint author), NYU, DEPT CHEM, NEW YORK, NY 10003 USA. FU NCI NIH HHS [CA-28038, CA-20851, CA-46533] NR 163 TC 273 Z9 276 U1 1 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD FEB PY 1997 VL 10 IS 2 BP 111 EP 146 DI 10.1021/tx9601418 PG 36 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA WJ279 UT WOS:A1997WJ27900001 PM 9049424 ER PT J AU Chenna, A Singer, B AF Chenna, A Singer, B TI Synthesis of a benzene metabolite adduct, 3''-hydroxy-1,N-2-benzetheno-2'-deoxyguanosine, and its site-specific incorporation into DNA oligonucleotides SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID P-BENZOQUINONE; TOXICITY; DISPOSITION AB p-Benzoquinone (p-BQ) is a stable metabolite of benzene and a number of other drugs and chemicals. 2'-Deoxyguanosine was allowed to react with p-BQ in aqueous solution (pH 4.5, 7.4, and 9.3). At pH 7.4 and 9.3 one major product was found in low yield; at pH 4.5 no product was detected. In nonaqueous conditions (DMF or DMSO, in the presence of K2CO3), an unstable intermediate with two p-BQ moieties was found which slowly converted to the product formed in aqueous solution. These products were isolated by silica gel, column chromatography, or reverse-phase HPLC and characterized by UV, H-1 NMR, FAB-MS, and electrospray MS. The major stable product of the reaction of dG with p-BQ is an exocyclic compound, 3''-hydroxy-1,N-2-benzetheno-2'-deoxyguanosine (p-BQ-dG). Incorporation of the adduct into oligonucleotides requires the protection of three hydroxyl groups (C7, 5', 3') and the amino group at N5. The exocyclic hydroxyl and the amino group were protected by acylation after protecting the 5- and the S'-hydroxyl groups of the sugar moiety by 4,4'-dimethoxytrityl and a cyanoethyl N,N-diisopropylphosphoramidite group, respectively. This is the first time the fully protected phosphoramidite of p-BQ-dG has been prepared and used in the synthesis of site specifically modified oligonucleotides. After deprotection with 1,3-diazabicyclo[5.4.0]undec-7-ene (DBU), in ethanol, oligomers purified by gel electrophoresis and HPLC. Enzymatic hydrolysis and analysis by HPLC confirmed the presence of p-BQ-dG in the oligomers. These oligomers are now under investigation for their biochemical properties. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DONNER LAB, DIV LIFE SCI, BERKELEY, CA 94720 USA. FU NIEHS NIH HHS [ES07368] NR 29 TC 25 Z9 25 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0893-228X EI 1520-5010 J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD FEB PY 1997 VL 10 IS 2 BP 165 EP 171 DI 10.1021/tx960168r PG 7 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA WJ279 UT WOS:A1997WJ27900004 PM 9049427 ER PT J AU Kukkadapu, RK Witkowski, MS Amonette, JE AF Kukkadapu, RK Witkowski, MS Amonette, JE TI Synthesis of a low-carbonate high-charge hydrotalcite-like compound at ambient pressure and atmosphere SO CHEMISTRY OF MATERIALS LA English DT Article ID PHYSICOCHEMICAL PROPERTIES; PILLARED HYDROTALCITE AB Hydrotalcite-like compounds (HTLCs) having low (<5%) carbonate content and high (X(Al) > 0.33) layer charge can be synthesized under ambient pressure and atmosphere. This new approach uses terephthalate anions and manipulation of suspension pH to increase the substitution of Al for Mg in the octahedral sheet. Unit-cell dimensions vary linearly with X(Al) The surprisingly labile nature of the octahedral sheet suggests new possibilities for the synthesis of materials with layered hydroxide and oxide structures. C1 PACIFIC NW LAB, ENVIRONM & HLTH SCI DIV, RICHLAND, WA 99352 USA. NR 16 TC 27 Z9 27 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD FEB PY 1997 VL 9 IS 2 BP 417 EP + DI 10.1021/cm960536c PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WJ270 UT WOS:A1997WJ27000006 ER PT J AU Martino, A Yamanaka, SA Kawola, JS Loy, DA AF Martino, A Yamanaka, SA Kawola, JS Loy, DA TI Encapsulation of gold nanoclusters in silica materials via an inverse micelle/sol-gel synthesis SO CHEMISTRY OF MATERIALS LA English DT Article ID SEMICONDUCTOR PARTICLES; OPTICAL-PROPERTIES; AQUEOUS-SOLUTION; COLLOIDAL METAL; CDS PARTICLES; CLUSTERS; GLASSES; COMPLEXES; CATALYSTS; ATOMS AB Nanometer-sized gold particles were encapsulated in the micropores of xerogels and aerogels. The synthesis involves the sequential reduction of a gold salt followed by sol-gel processing in an inverse micelle solution. The inverse micelle solution solubilizes the metal salt and provides a microreactor for the nucleation, growth, and stabilization of the nanometer-sized clusters. Hydrolysis and condensation of an added siloxane precursor produces a wet gel embedding the particles. Characterization of the particle size and composition and the particle growth process was completed with transmission electron microscopy (TEM), electron diffraction, and UV-visible absorption spectrometry. Characterization of the gel surface areas was completed with N-2 porosimetry. Material properties determined as a function of the gel precursor (TEOS vs a prehydrolyzed form of TEOS), the water to gel precursor reaction stoichiometry, and surfactant concentration are discussed in terms of the unique solution chemistry occurring in the microheterogeneous inverse micelle solutions. C1 TEXAS INSTRUMENTS INC, DALLAS, TX 75265 USA. SANDIA NATL LABS, PROPERTIES ORGAN MAT DEPT, ALBUQUERQUE, NM 87185 USA. RP Martino, A (reprint author), SANDIA NATL LABS, FUEL SCI DEPT, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Loy, Douglas/D-4847-2009 OI Loy, Douglas/0000-0001-7635-9958 NR 72 TC 63 Z9 64 U1 1 U2 23 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0897-4756 EI 1520-5002 J9 CHEM MATER JI Chem. Mat. PD FEB PY 1997 VL 9 IS 2 BP 423 EP 429 DI 10.1021/cm9604625 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WJ270 UT WOS:A1997WJ27000008 ER PT J AU Su, K Tilley, TD AF Su, K Tilley, TD TI Molecular routes es metal oxides sand metal silicates, synthesis and thermal decomposition studies of eclipsed Mo-2[O2Si(O(t)Bu)(2)](3) and W-2(NHMe(2))(2)[O2Si(O(t)Bu)(2)](2)[OSi(OH)(O(t)Bu)(2)](2) SO CHEMISTRY OF MATERIALS LA English DT Article ID TUNGSTEN TRIPLE BOND; STRUCTURAL CHARACTERIZATION; AMORPHOUS OXIDE; PRECURSORS; CATALYSTS; POLYMETALLOXANES; OXIDATION; MECHANISM; ALKOXIDES; HOMOLOGS AB Reaction of Mo-2(NMe(2))(6) with 3 equiv of ((t)BuO)(2)Si(OH)(2) afforded a new siloxide complex, Mo-2[O2Si(O(t)Bu)(2)](3) (1), as the only metal-containing product. An X-ray crystal structure determination reveals that I adopts an eclipsed structure with three di-tert-butoxysilanediolato ligands bridging themolybdenum centers in a symmetrical fashion. Lewis acidic complex 1 forms an isolable adduct with pyridine. Reaction of W-2(NMe(2))(6) with 3 equiv of ((t)BuO)(2)Si(OH)(2) afforded W-2(NHMe(2))(2)[O2Si(O(t)Bu)(2)](2)[OSi(OH)(O(t)Bu)(2)](2) (3), which was isolated as air-sensitive orange crystals. In this molecule, two O2Si(O(t)Bu)(2) ligands bridge the W=W bond in an eta(1),eta(1) fashion, and OSi(OH)(O(t)Bu)(2) ligands are coordinated to each W atom. This molecule adopts a highly eclipsed conformation and has a 2-fold axis of symmetry which perpendicularly bisects the tungsten-tungsten bond. Complex 1 undergoes a two-step weight loss (by TGA), which corresponds to the initial loss of isobutene and water (at ca. 200 degrees C), followed by the loss of molybdenum by evaporation of MoO3 at 700-1050 degrees C. The pyrolysis of 1 at 550 degrees C for 2 h under argon gave a ceramic material with the approximate formula Mo2Si3O10. When the sample was heated at 1200 degrees C for 1 h, evaporation of MoO3 occurred and the final ceramic material had a composition of Mo0.5Si3O6.5. Very low carbon contents for these materials are consistent with a clean elimination process during the pyrolysis. The material heated to 550 degrees C is amorphous, while the material taken to 1200 degrees C contains MoO2 as the only crystalline phase. Pyrolysis of 1 in air at 1200 degrees C resulted in the extensive loss of molybdenum (2.14% Mo; no crystalline phases by XRD). Interestingly, pyrolysis of small crystals of 1 occurs with retention of the crystals' shape and size, despite a great loss in weight (75%). Pyrolysis of 3 at 550 and 1200 degrees C under argon produced ceramic materials consistent with the formulas W2.2Si4O17.4 and W2.2Si4O13, respectively. While the 550 degrees C ceramic is amorphous, the 1200 degrees C material contains crystalline W and WO2 (by XRD analysis). C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 44 TC 42 Z9 42 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD FEB PY 1997 VL 9 IS 2 BP 588 EP 595 DI 10.1021/cm960413s PG 8 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WJ270 UT WOS:A1997WJ27000030 ER PT J AU Sullivan, EJ Hunter, DB Bowman, RS AF Sullivan, EJ Hunter, DB Bowman, RS TI Topological and thermal properties of surfactant-modified clinoptilolite studied by Tapping-mode(TM) atomic force microscopy and high-resolution thermogravimetric analysis SO CLAYS AND CLAY MINERALS LA English DT Article DE hexadecyltrimethylammonium; muscovite mica; surface imaging; thermal analysis; zeolite ID ZEOLITE SURFACES; SORPTION; MOISTURE; CATIONS AB Unmodified and surfactant-modified clinoptilolite-rich tuff (referred to here as ''clinoptilolite'') and muscovite mica were examined with tapping-mode atomic force microscopy (TMAFM) and high-resolution thermogravimetric analysis (HR-TGA) in order to elucidate patterns of hexadecyltrimethylammonium bromide (HDTMA) sorption on the treated surface and to understand the mechanisms of this sorption. TMAFM images were obtained to a scale of 50 nm by 50 nm. The images of unmodified clinoptilolite showed a framework pattern on the ac plane, comparable to previously reported images. Images of modified clinoptilolite at 12.5% and 25% of external cation exchange capacity (ECEC) coverage by HDTMA showed evidence of the HDTMA molecules arranged as elongated, topographically raised features on the ne plane. At 50% HDTMA coverage, the images contained what appeared to be agglomerations of surfactant tail groups. The z-direction thickness of the raised features on the 12.5% coverage sample corresponded to the thickness of the carbon chain of the surfactant tail-group (0.4 nm), whereas the z-thickness on the 25% coverage sample was between 0.4 and 0.8 nm, indicating crossing of doubling of tail groups. Repulsive forces between the modified clinoptilolite and the silicon TMAFM probe increased with increasing HDTMA coverage. HR-TGA showed a 100 degrees C increase in HDTMA pyrolysis temperatures at coverages of less than 50%, probably due to an increased stabilization of the HDTMA due to direct tail interactions with the clinoptilolite surface at lower coverages versus smaller stabilization due to surfactant tail-tail interactions at higher coverages. Our results indicate that buildup of HDTMA admicelles or some form of a bilayer begins before full monolayer coverage is complete. C1 NEW MEXICO INST MIN & TECHNOL,GEOPHYS RES CTR,SOCORRO,NM 87801. UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,DIV BIOGEOCHEM,AIKEN,SC 29801. RP Sullivan, EJ (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT EARTH & ENVIRONM SCI,SOCORRO,NM 87801, USA. NR 25 TC 72 Z9 72 U1 1 U2 6 PU CLAY MINERALS SOCIETY PI BOULDER PA PO BOX 4416, BOULDER, CO 80306 SN 0009-8604 J9 CLAY CLAY MINER JI Clay Clay Min. PD FEB PY 1997 VL 45 IS 1 BP 42 EP 53 DI 10.1346/CCMN.1997.0450105 PG 12 WC Chemistry, Physical; Geosciences, Multidisciplinary; Mineralogy; Soil Science SC Chemistry; Geology; Mineralogy; Agriculture GA XB133 UT WOS:A1997XB13300005 ER PT J AU King, AW Post, WM Wullschleger, SD AF King, AW Post, WM Wullschleger, SD TI The potential response of terrestrial carbon storage to changes in climate and atmospheric CO2 SO CLIMATIC CHANGE LA English DT Article ID BIOSPHERE; MODEL; SOIL; SENSITIVITY; CYCLE; TEMPERATURE; SIMULATION; PHYSIOLOGY; VEGETATION; TURNOVER AB We use a georeferenced model of ecosystem carbon dynamics to explore the sensitivity of global terrestrial carbon storage to changes in atmospheric CO2 and climate. We model changes in ecosystem carbon density, but we do not model shifts in vegetation type. A model of annual NPP is coupled with a model of carbon allocation in vegetation and a model of decomposition and soil carbon dynamics. NPP is a function of climate and atmospheric CO2 concentration. The CO2 response is derived from a biochemical model of photosynthesis. With no change in climate, a doubling of atmospheric CO2 from 280 ppm to 560 ppm enhances equilibrium global NPP by 16.9%; equilibrium global terrestrial ecosystem carbon (TEC) increases by 14.9%. Simulations with no change in atmospheric CO2 concentration but changes in climate from five atmospheric general circulation models yield increases in global NPP of 10.0-14.8%. The changes in NPP are very nearly balanced by changes in decomposition, and the resulting changes in TEC range from an increase of 1.1% to a decrease of 1.1%. These results are similar to those from analyses using bioclimatic biome models that simulate shifts in ecosystem distribution but do not model changes in carbon density within vegetation types. With changes in both climate and a doubling of atmospheric CO2, our model generates increases in NPP of 30.2-36.5%. The increases in NPP and litter inputs to the soil more than compensate for any climate stimulation of decomposition and lead to increases in global TEC of 15.4-18.2%. RP King, AW (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Wullschleger, Stan/B-8297-2012; Post, Wilfred/B-8959-2012 OI Wullschleger, Stan/0000-0002-9869-0446; NR 52 TC 87 Z9 102 U1 1 U2 20 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0165-0009 J9 CLIMATIC CHANGE JI Clim. Change PD FEB PY 1997 VL 35 IS 2 BP 199 EP 227 DI 10.1023/A:1005317530770 PG 29 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WN556 UT WOS:A1997WN55600005 ER PT J AU Bose, P Shermer, T Toussaint, G Zhu, BH AF Bose, P Shermer, T Toussaint, G Zhu, BH TI Guarding polyhedral terrains SO COMPUTATIONAL GEOMETRY-THEORY AND APPLICATIONS LA English DT Article DE polyhedral terrains; art gallery theorems; matching ID POLYGON; THEOREM AB We prove that [n/2] vertex guards are always sufficient and sometimes necessary to guard the surface of an n-vertex polyhedral terrain. We also show that [(4n - 4)/13] edge guards are sometimes necessary to guard the surface of an n-vertex polyhedral terrain. The upper bound on the number of edge guards is [n/3] (Everett and Rivera-Campo, 1994). Since both upper bounds are based on the four color theorem, no practical polynomial time algorithm achieving these bounds seems to exist, but we present a linear time algorithm for placing [3n/5] vertex guards for covering a polyhedral terrain and a linear time algorithm for placing [2n/5] edge guards. C1 UNIV QUEBEC,DEPT MATH & INFORMAT,TROIS RIVIERES,PQ G9A 5H7,CANADA. SIMON FRASER UNIV,SCH COMP SCI,BURNABY,BC V5A 1S6,CANADA. MCGILL UNIV,SCH COMP SCI,MONTREAL,PQ H3A 2A7,CANADA. LOS ALAMOS NATL LAB,GRP C3,LOS ALAMOS,NM 87545. RI Zhu, Binhai/A-2911-2008 NR 16 TC 31 Z9 31 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0925-7721 J9 COMP GEOM-THEOR APPL JI Comput. Geom.-Theory Appl. PD FEB PY 1997 VL 7 IS 3 BP 173 EP 185 DI 10.1016/0925-7721(95)00034-8 PG 13 WC Mathematics, Applied; Mathematics SC Mathematics GA WG515 UT WOS:A1997WG51500003 ER PT J AU Latombe, JC Wilson, RH Cazals, F AF Latombe, JC Wilson, RH Cazals, F TI Assembly sequencing with toleranced parts SO COMPUTER-AIDED DESIGN LA English DT Article DE assembly planning; assembly sequencing; solid modelling; tolerancing; non-directional blocking graph ID TRANSLATIONS; COMPLEXITY AB The goal of assembly sequencing is to plan a feasible series of operations to construct a product from its individual parts. Previous research has investigated assembly sequencing under the assumption that parts have nominal geometry. This paper considers the case where parts have toleranced geometry. Its main contribution is an efficient procedure that decides if a product admits an assembly sequence with infinite translations (i.e. translations that can be extended arbitrarily far along a fixed direction), that is feasible for all possible instances of the components within the specified tolerances. If the product admits one such sequence, the procedure can also generate it. For the cases where there exists no such assembly sequence, another procedure is proposed which generates assembly sequences that are feasible only for some values of the toleranced dimensions. If this procedure produces no such sequence, then no instance of the product is assemblable. These two procedures are described for 2D assemblies made of polygonial parts and for 3D assemblies made of polyhedral parts. So far, only the first has been implemented (for the planar case). This work assumes a simple, but non-trivial tolerance language that falls short of capturing all imperfections of a manufacturing process. In particular, it assumes that faces and edges have perfect relative orientations. Thus, it is only one step towards dealing with tolerances in assembly sequencing. C1 SANDIA NATL LABS, INTELLIGENT SYST & ROBOT CTR, ALBUQUERQUE, NM 87185 USA. RP Latombe, JC (reprint author), STANFORD UNIV, DEPT COMP SCI, ROBOT LAB, STANFORD, CA 94305 USA. NR 44 TC 33 Z9 34 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0010-4485 J9 COMPUT AIDED DESIGN JI Comput.-Aided Des. PD FEB PY 1997 VL 29 IS 2 BP 159 EP 174 DI 10.1016/S0010-4485(96)00044-9 PG 16 WC Computer Science, Software Engineering SC Computer Science GA WD193 UT WOS:A1997WD19300008 ER PT J AU Hyman, JM Shashkov, M AF Hyman, JM Shashkov, M TI Natural discretizations for the divergence, gradient, and curl on logically rectangular grids SO COMPUTERS & MATHEMATICS WITH APPLICATIONS LA English DT Article DE finite-difference; logically-rectangular grids; discrete vector analysis ID REFERENCE-OPERATOR METHOD; DIFFERENCE-SCHEMES; DIRICHLET CELLS; EQUATIONS AB This is the first in series of papers creating a discrete analog of vector analysis on logically rectangular, nonorthogonal, nonsmooth grids. We introduce notations for 2-D logically rectangular grids, describe both cell-valued and nodal discretizations for scalar functions, and construct the natural discretizations of vector fields, using the vector components normal and tangential to the cell boundaries. We then define natural discrete analogs of the divergence, gradient, and curl operators based on coordinate invariant definitions and interpret these formulas in terms of curvilinear coordinates, such as length of elements of coordinate lines, areas of elements of coordinate surfaces, and elementary volumes. We introduce the discrete volume integral of scalar functions, the discrete surface integral, and a discrete analog of the line integral and prove discrete versions of the main theorems relating these objects. These theorems include the following: the discrete analog of relationship div (A) over right arrow = 0 if and only if (A) over right arrow = curl (B) over right arrow; curl (A) over right arrow = 0 if and only if (A) over right arrow = grad phi; if (A) over right arrow = grad phi, then the line integral does not depend on path; and if the line integral of a vector function is equal to zero for any closed path, then this vector is the gradient of a scalar function. Last, we define the discrete operators DIV, GRAD, and CURL in terms of primitive differencing operators (based on forward and backward differences) and primitive metric operators (related to multiplications of discrete functions by length of edges, areas of surfaces, and volumes of 3-D cells). These formulations elucidate the structure of the discrete operators and are useful when investigating the relationships between operators and their adjoints. RP Hyman, JM (reprint author), LOS ALAMOS NATL LAB,T 7,MS B284,LOS ALAMOS,NM 87545, USA. NR 66 TC 105 Z9 107 U1 2 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0898-1221 J9 COMPUT MATH APPL JI Comput. Math. Appl. PD FEB PY 1997 VL 33 IS 4 BP 81 EP 104 DI 10.1016/S0898-1221(97)00009-6 PG 24 WC Mathematics, Applied SC Mathematics GA WM412 UT WOS:A1997WM41200009 ER PT J AU Zhu, YY Zacharia, T Cescotto, S AF Zhu, YY Zacharia, T Cescotto, S TI Application of fully automatic remeshing to complex metal-forming analyses SO COMPUTERS & STRUCTURES LA English DT Article ID FINITE-ELEMENT ANALYSIS; SIMULATION AB The purpose of this paper is to illustrate the importance of automatic remeshing in the simulation of complex metal-forming processes. A fully automatic remeshing procedure has been developed to enable modeling of a whole forming process of industrial parts without user intervention. The remeshing scheme was implemented in a finite element code, LAGAMINE. The different features of this technique are presented with two industrial examples: (1) an axisymmetric forging; and (2) an axisymmetric forward extrusion. In both cases, an elasto-viscoplastic material model was used. C1 UNIV LIEGE,DEPT MSM,B-4000 LIEGE,BELGIUM. RP Zhu, YY (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,MAT PROC MODELING GRP,OAK RIDGE,TN 37831, USA. OI Zacharia, Thomas/0000-0001-6463-5425 NR 26 TC 10 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0045-7949 J9 COMPUT STRUCT JI Comput. Struct. PD FEB PY 1997 VL 62 IS 3 BP 417 EP 427 DI 10.1016/S0045-7949(96)00231-3 PG 11 WC Computer Science, Interdisciplinary Applications; Engineering, Civil SC Computer Science; Engineering GA WC085 UT WOS:A1997WC08500001 ER PT J AU Vaidya, RU Butt, DP Hersman, LE Zurek, AK AF Vaidya, RU Butt, DP Hersman, LE Zurek, AK TI Effect of microbiologically influenced corrosion on the tensile stress-strain response of aluminum and alumina-particle reinforced aluminum composite SO CORROSION LA English DT Article DE Al 6061; biofilm composite; microbiologically influenced corrosion; strain; stress; tensile; Pseudomonas ID MATRIX COMPOSITES AB The tensile stress-strain responses of Al 6061 (UNS A96061) and alumina (Al2O3)-particle reinforced Al 6061 composite were investigated while exposed to a marine bacteria, Pseudomonas species strain NCMB 2021. Tensile responses of the unreinforced alloy and composite samples were altered by the microbial exposures. The strain to failure of the unreinforced alloy was lowered significantly as a result of microbiologically influenced corrosion (MIC). The effect of MIC on composite samples was more drastic. The ultimate tensile strength (UTS) and strain to failure were reduced significantly in the presence of the microbial species. Changes in the stress-strain responses of both materials were attributed to preferential formation of surface voids as a result of biofilm formation and the MIC process. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. RP Vaidya, RU (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,POB 1663,LOS ALAMOS,NM 87545, USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 26 TC 12 Z9 15 U1 2 U2 3 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD FEB PY 1997 VL 53 IS 2 BP 136 EP 141 PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XU783 UT WOS:A1997XU78300007 ER PT J AU Gardner, DL Swift, GW AF Gardner, DL Swift, GW TI Use of inertance in orifice pulse tube refrigerators SO CRYOGENICS LA English DT Article DE pulse tube refrigerator; gas inertia; inertance AB In efficient Stirling-cycle cryocoolers, the oscillating velocity leads the oscillating pressure at the hot end of the regenerator, and lags behind it at the cold end. In single-orifice pulse tube refrigerators, the velocity leads pressure at both ends, resulting in lower efficiency. The phase shift between oscillating pressure and oscillating velocity at the cold end is determined in part by the purely resistive nature of the ''orifice'' of the orifice pulse tube refrigerator, so that the pressure difference across the orifice is in phase with the velocity through it. We show that the phase shift between velocity and pressure can be shifted to the more efficient Stirling values by adding an ''inertance'' in series with the orifice. The word ''inertance'' is an acoustics term connoting both inertia and inductance, because it is due to inertial effects of moving gas and is the acoustic analog of electrical inductance. Use of an inertance is significantly beneficial only when the gross cooling power is sufficiently large. (C) 1997 Elsevier Science Limited. RP Gardner, DL (reprint author), LOS ALAMOS NATL LAB,CONDENSED MATTER & THERMAL PHYS GRP,MAIL STOP K764,LOS ALAMOS,NM 87545, USA. NR 11 TC 58 Z9 65 U1 2 U2 12 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0011-2275 J9 CRYOGENICS JI Cryogenics PD FEB PY 1997 VL 37 IS 2 BP 117 EP 121 DI 10.1016/S0011-2275(96)00107-5 PG 5 WC Thermodynamics; Physics, Applied SC Thermodynamics; Physics GA WG510 UT WOS:A1997WG51000008 ER PT J AU Quesada, MA AF Quesada, MA TI Replaceable polymers in DNA sequencing by capillary electrophoresis SO CURRENT OPINION IN BIOTECHNOLOGY LA English DT Article ID CROSS-LINKED POLYACRYLAMIDE; SINGLE-STRANDED-DNA; GEL-ELECTROPHORESIS; HIGH-SPEED; REPTATION THEORY; AGAROSE GELS; SEPARATION; MOBILITY; FRAGMENTS; FIELD AB Much progress has been made in the development of replaceable sieving polymers and capillary coatings for high-performance DNA sequencing by capillary electrophoresis. Several studies of parameters that affect resolution, read length and reproducibility have begun to reveal the physical mechanisms acting on single-stranded DNA during electrophoresis through semidilute polymer solutions. Recently developed electro-osmosis-inhibiting matrix polymers have simplified the process of coating capillaries, facilitating the automation of high-throughput parallel systems for large-scale sequencing. RP Quesada, MA (reprint author), BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973, USA. NR 65 TC 50 Z9 52 U1 0 U2 2 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0958-1669 J9 CURR OPIN BIOTECH JI Curr. Opin. Biotechnol. PD FEB PY 1997 VL 8 IS 1 BP 82 EP 93 DI 10.1016/S0958-1669(97)80162-0 PG 12 WC Biochemical Research Methods; Biotechnology & Applied Microbiology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology GA WF599 UT WOS:A1997WF59900013 PM 9013653 ER PT J AU Abbott, NL AF Abbott, NL TI Surface effects on orientation of liquid crystals SO CURRENT OPINION IN COLLOID & INTERFACE SCIENCE LA English DT Review ID OPTICAL 2ND-HARMONIC GENERATION; SELF-ASSEMBLED MONOLAYERS; ALIGNMENT; FILMS; POLYIMIDE; MOLECULES; LAYERS AB Optical second harmonic generation (SHG) is now being used to measure the orientations of mesogens adsorbed at a variety of polar organic surfaces (e.g. rubbed films of polyimides). For some surfaces, at least, these measurements can be used to predict the anchoring of bulk liquid crystals. Few rules exist, however, to guide the design of surfaces for manipulation of the orientations of adsorbed mesogens (and thus bulk anchoring). These rules are difficult to establish on surfaces as complicated as those of rubbed polymers. Self-assembled monolayers formed from functionalized alkanethiols on semi-transparent films of gold and silver do permit the synthesis of well defined surfaces, and these surfaces are now being used in studies of the anchoring of liquid crystals. Orientations of liquid crystals on these surfaces differ substantially from orientations observed in the past on surfaces formed from organosilanes. (C) Current Chemistry Ltd. RP Abbott, NL (reprint author), LAWRENCE LIVERMORE NATL LAB, DEPT CHEM ENGN & MAT SCI, DAVIS, CA 95616 USA. NR 46 TC 13 Z9 13 U1 0 U2 22 PU ELSEVIER SCIENCE LONDON PI LONDON PA 84 THEOBALDS RD, LONDON WC1X 8RR, ENGLAND SN 1359-0294 J9 CURR OPIN COLLOID IN JI Curr. Opin. Colloid Interface Sci. PD FEB PY 1997 VL 2 IS 1 BP 76 EP 82 PG 7 WC Chemistry, Physical SC Chemistry GA WH824 UT WOS:A1997WH82400010 ER PT J AU Clarke, J AF Clarke, J TI High-T-c SQUIDs SO CURRENT OPINION IN SOLID STATE & MATERIALS SCIENCE LA English DT Review ID QUANTUM INTERFERENCE DEVICE; MAGNETIC-FLUX NOISE; THIN-FILMS; 1/F NOISE; DC SQUIDS; MAGNETOMETER; YBA2CU3O7-X; GRADIOMETER; JUNCTIONS; TRANSFORMERS AB Magnetometers based on superconducting quantum interference devices (SQUIDs), fabricated from thin films of YBa2Cu3O7-x and operated in liquid nitrogen at 77K, have achieved a magnetic field noise below 10 fT Hz(-1/2). These devices are now sufficiently sensitive for use in an intriguing variety of applications, including geophysics, magnetocardiology, nondestructive evaluation of metal structures, and scanning SQUID microscopes. C1 LAWRENCE BERKELEY NATL LAB, DIV SCI MAT, BERKELEY, CA 94720 USA. RP Clarke, J (reprint author), UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 54 TC 23 Z9 24 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-0286 J9 CURR OPIN SOLID ST M JI Curr. Opin. Solid State Mat. Sci. PD FEB PY 1997 VL 2 IS 1 BP 3 EP 10 DI 10.1016/S1359-0286(97)80098-8 PG 8 WC Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA WL851 UT WOS:A1997WL85100002 ER PT J AU Olshansky, SJ Carnes, BA AF Olshansky, SJ Carnes, BA TI Ever since Gompertz SO DEMOGRAPHY LA English DT Article; Proceedings Paper CT 48th Annual Meeting of the Gerontological-Society-of-America CY NOV 15-19, 1995 CL LOS ANGELES, CA SP Gerontol Soc Amer ID MORTALITY-RATES; HUMAN SENESCENCE; OLDEST-OLD; PERSPECTIVES; DYNAMICS; SYSTEMS; FRAILTY AB In 1825 British actuary Benjamin Gompertz made a simple but important observation that a law of geometrical progression pervades large portions of different tables of mortality for humans. The simple formula he derived describing the exponential rise in death rates between sexual maturity and old age is commonly referred to as the Gompertz equation-a formula that remains a valuable fool in demography and in other scientific disciplines. Gompertz's observation of a mathematical regularity in the life table led him to believe in the presence of a law of mortality that explained why common age patterns of death exist. This law of mortality has captured the attention of scientists for the past 170 years because it was the first among what are now several reliable empirical tools for describing the dying-out process of many living organisms during a significant portion of their life spans. In this paper we review the literature on Gompertz's law of mortality and discuss the importance of his observations and insights in light of research on aging that has taken place since then. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. RP Olshansky, SJ (reprint author), UNIV CHICAGO,DEPT MED,5841 S MARYLAND AVE,CHICAGO,IL 60637, USA. FU NIA NIH HHS [AG-00577-01] NR 94 TC 92 Z9 99 U1 0 U2 8 PU POPULATION ASSN AMER PI WASHINGTON PA 1722 N ST NW, WASHINGTON, DC 20036 SN 0070-3370 J9 DEMOGRAPHY JI Demography PD FEB PY 1997 VL 34 IS 1 BP 1 EP 15 DI 10.2307/2061656 PG 15 WC Demography SC Demography GA WP314 UT WOS:A1997WP31400001 PM 9074828 ER PT J AU Ramasamy, R Oates, PJ Schaefer, S AF Ramasamy, R Oates, PJ Schaefer, S TI Aldose reductase inhibition protects diabetic and nondiabetic rat hearts from ischemic injury SO DIABETES LA English DT Article ID INTRACELLULAR PH; GLOBAL-ISCHEMIA; PERFUSED HEART; REPERFUSION; METABOLISM; MECHANISMS; MELLITUS; SORBITOL; EXCHANGE; RECOVERY AB Diabetes increases the incidence of cardiovascular disease as well as the complications of myocardial infarction. Studies using animal models of diabetes have demonstrated that the metabolic alterations occurring at the myocyte level may contribute to the severity of ischemic injury in diabetic hearts. Of the several mechanisms being investigated to understand the pathogenesis of diabetic complications, the increased metabolism of glucose via the polyol pathway has received considerable attention. Deviant metabolic regulation due to increased flux through aldose reductase in diabetic hearts may influence the ability of the myocardium to withstand ischemia insult. To determine if aldose reductase inhibition improves tolerance to ischemia, hearts from acute type I diabetic and nondiabetic control rats were isolated and retrograde perfused. Each group was exposed to 1 mu mol/l zopolrestat, a specific inhibitor of aldose reductase, for 10 min, followed by 20 min of global ischemia and 60 min of reperfusion in the absence of zopolrestat. Zopolrestat reduced sorbitol levels before ischemia in diabetic hearts. The cytosolic redox state (NADH/NAD(+)), as measured by lactate-to-pyruvate ratios, was significantly lowered under baseline, ischemic, and reperfusion conditions in diabetic hearts perfused with zopolrestat. In these diabetic hearts, ATP was significantly higher in zopolrestat hearts during ischemia, as were phosphocreatine and left ventricular-developed pressure on reperfusion. Zopolrestat provided similar metabolic and functional benefits in nondiabetic hearts. Creatine kinase release was reduced by similar to 50% in both nondiabetic and diabetic hearts treated with zopolrestat. These data indicate that inhibition of aldose reductase activity preserves high-energy phosphates, maintains a lower cytosolic NADH/NAD(+) ratio, and markedly protects both diabetic and nondiabetic hearts during ischemia and reperfusion. C1 PFIZER INC,DIV CENT RES,DEPT METAB DIS,GROTON,CT 06340. RP Ramasamy, R (reprint author), LAWRENCE LIVERMORE NATL LAB,DIV CARDIOVASC MED,TB 172,DEPT INTERNAL MED,BIOLETTI WAY,DAVIS,CA 95616, USA. FU NCRR NIH HHS [RR02511] NR 38 TC 103 Z9 105 U1 0 U2 6 PU AMER DIABETES ASSOC PI ALEXANDRIA PA 1660 DUKE ST, ALEXANDRIA, VA 22314 SN 0012-1797 J9 DIABETES JI Diabetes PD FEB PY 1997 VL 46 IS 2 BP 292 EP 300 DI 10.2337/diabetes.46.2.292 PG 9 WC Endocrinology & Metabolism SC Endocrinology & Metabolism GA WD288 UT WOS:A1997WD28800018 PM 9000707 ER PT J AU Basu, R Dutt, S Chhabra, JK Madhavan, R Saha, BK Sinha, RK Majumdar, S Sheshagiri, N Jacob, A Dayal, P Singh, N Mukhopadhyay, S Malhotra, PP Sethuraman, R Srinivasan, G Dhoot, PN Dass, G Singh, H Gupta, SN Bhatkar, VP Devgan, J Pande, YK Khanna, SC Mashelkar, A Singh, PP Kaura, HK Tuli, V Raman, KS Gopalakrishnan, S Chopra, V Mittal, KS Ramesh Bhatnagar, VK Vaid, ON AF Basu, R Dutt, S Chhabra, JK Madhavan, R Saha, BK Sinha, RK Majumdar, S Sheshagiri, N Jacob, A Dayal, P Singh, N Mukhopadhyay, S Malhotra, PP Sethuraman, R Srinivasan, G Dhoot, PN Dass, G Singh, H Gupta, SN Bhatkar, VP Devgan, J Pande, YK Khanna, SC Mashelkar, A Singh, PP Kaura, HK Tuli, V Raman, KS Gopalakrishnan, S Chopra, V Mittal, KS Ramesh Bhatnagar, VK Vaid, ON TI Report of the working group on electronics industry for the ninth five year plan SO ELECTRONICS INFORMATION & PLANNING LA English DT Article RP Basu, R (reprint author), US DOE,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELECTRONICS INFORMATION & PLANNING PI NEW DELHI PA DEPT ELECTRONICS, ELECTRONICS NIKETAN, 6, CGO COMPLEX, NEW DELHI 110-003, INDIA SN 0304-9876 J9 ELECTRON INFORM PLAN JI Electron. Inf. Plan. PD FEB PY 1997 VL 24 IS 5 BP 239 EP 292 PG 54 WC Engineering, Electrical & Electronic SC Engineering GA XA269 UT WOS:A1997XA26900001 ER PT J AU Reck, RA Hoag, KJ AF Reck, RA Hoag, KJ TI A comparison of greenhouse gas mitigation options SO ENERGY LA English DT Article AB The mitigation of atmospheric greenhouse gas emissions is important for minimizing the anthropogenic contributions to climate change. These concerns have led to the investigation of many technologies and strategies for mitigation, both in the U.S. and abroad. One technology explored at ANL is integrated gasification combined cycle (IGCC) power generation, which is based on extraction of CO2 by a solvent. The IGCC process reduces CO2 production through efficient fuel use, which makes CO2 recovery less expensive than conventional systems. Recovery using the following solvents was explored in detail: monoethanolamine (MEA), glycol, chilled methanol, and hot potassium carbonate. Other incentive-based options for mitigation have also been explored, including market incentives (carbon fees and tradable permits) and regulatory measures. Our work suggests a complex global strategy will be necessary to optimize options for mitigation of global climate change, one that takes into account both local and regional considerations. RP Reck, RA (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 11 Z9 13 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD FEB-MAR PY 1997 VL 22 IS 2-3 BP 115 EP 120 DI 10.1016/S0360-5442(96)00108-9 PG 6 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA WD708 UT WOS:A1997WD70800004 ER PT J AU Steinberg, M AF Steinberg, M TI The Carnol process system for CO2 mitigation and methanol production SO ENERGY LA English DT Article AB The feasibility of an alternative CO2 mitigation system and a methanol production process is investigated. The Carnol system has three components: (i) a coal-fired power plant supplying flue gas CO2, (ii) a process which converts the CO2 in the presence of He from natural gas to methanol, (iii) use of methanol as a fuel component in the automotive sector. For the methanol production process alone, up to 100% CO2 emission reduction can be achieved; for the entire system, up to 65% CO2 emission reduction can be obtained. The Carnol system is technically feasible and economically competitive with alternative CO2-disposal systems for coal-fired power plants. The Carnol process is estimated to be economically attractive compared to the current market price of methanol, especially if credit can be taken for carbon as a marketable coproduct. Copyright (C) 1996 Elsevier Science Ltd. RP Steinberg, M (reprint author), BROOKHAVEN NATL LAB,DEPT ADV TECHNOL,ENGN RES & APPLICAT DIV,UPTON,NY 11973, USA. NR 12 TC 2 Z9 2 U1 1 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-5442 J9 ENERGY JI Energy PD FEB-MAR PY 1997 VL 22 IS 2-3 BP 143 EP 149 DI 10.1016/S0360-5442(96)00138-7 PG 7 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA WD708 UT WOS:A1997WD70800008 ER PT J AU Neal, JT Magorian, TR AF Neal, JT Magorian, TR TI Geologic site characterization (GSC) principles derived from storage and mining projects in salt, with application to environmental surety SO ENVIRONMENTAL GEOLOGY LA English DT Article DE geologic site characterization; underground storage and mining; salt utilization; environmental and engineering geology reports ID INTERNAL KINEMATICS; DIAPIRS AB The source of many environmental incidents involving engineering works has been traced to inadequate geologic site characterization (GSC). Even though critics may argue that hindsight is almost always clearer than foresight, what is reasonable to some geologists may be overkill to others and GSC is often underperformed. Communication between designers, geologists, engineers, and regulators is paramount at all stages of a project, each recognizing the essential needs of the other. For large projects having substantial longevity, it is essential to periodically review initial conclusions because assumptions and criteria change as the geosciences evolve, engineering precepts are refined, and analytical capabilities increase. A brief consideration of the changing geological paradigms of the 1950s and 1960s as compared with the 1990s should leave little room for debate on this. Geologic site characterization should be a dynamic, continuing process. A balanced approach must be sought, to provide adequate information for safety of operations, neither slighting or overdoing the effort. Several examples are taken from the salt mining and storage industry, which illustrate these principles, but there is widespread application to other geological media and engineering projects. The ultimate benefit of valuing site characterization efforts may be more than just enhanced safety and health-costs not expended in lost facilities and ligation can become profit. RP Neal, JT (reprint author), SANDIA NATL LABS,UNDERGROUND STORAGE TECHNOL DEPT 6113,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 39 TC 4 Z9 7 U1 2 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD FEB PY 1997 VL 29 IS 3-4 BP 165 EP 175 PG 11 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA WN751 UT WOS:A1997WN75100004 ER PT J AU Drozhko, EG Glagolenko, YU Mokrov, YG Postovalova, GA Samsonova, LM Glagolev, AV TerSaakian, SA Glinsky, ML Vasilkova, NA Skokov, AV Wollenberg, HA Tsang, CF Frangos, W Solbau, RD Stevenson, KA Lowder, WM Foley, MG AF Drozhko, EG Glagolenko, YU Mokrov, YG Postovalova, GA Samsonova, LM Glagolev, AV TerSaakian, SA Glinsky, ML Vasilkova, NA Skokov, AV Wollenberg, HA Tsang, CF Frangos, W Solbau, RD Stevenson, KA Lowder, WM Foley, MG TI Joint Russian-American hydrogeological-geochemical studies of the Karachai-Mishelyak system, South Urals, Russia SO ENVIRONMENTAL GEOLOGY LA English DT Article DE fractured rock; radiometrics; hydrogeology; electrical geophysics ID RADIONUCLIDES AB In September 1994, a Russian-American team conducted hydrogeological, geochemical, geophysical, and radiometric measurements in the territory of the Mayak Production Association, Russia. The primary purpose of these operations was to examine the frontal area of a radioelement- and nitrate-laden groundwater plume moving from the disposal site, Lake Karachai, toward the Mishelyak River. Activities encompassed (1) isolation of hydrologic intervals in two wells and production of water from these intervals, to compare isolated versus open-well sampling methods and to determine hydraulic transmissivities of the aquifer(s); (2) surface and soil-water sampling, accompanying radiometric measurements and subsequent chemical analyses; and (3) electrical resistivity profiling in areas of expected contrasting resistivity. Preliminary results indicate that (1) Co-60, Cs-137, and Sr-90 are present in small concentrations (similar to 0.1% of permissible levels) in water of the Mishelyak River; (2) analyses of water samples collected by a downhole sampler and of water produced from packed-off intervals agree within limits of laboratory accuracy, attesting to the efficacy of the sampling methods presently used by the Russian workers; (3) considerable differences in contaminant concentrations exist between nearby wells, supporting the concept that the plume from Lake Karachai toward the Mishelyak River is controlled by steeply dipping fractures and shear zones; and (4) strong contrasts occur between the electrical resistivities of soil and bedrock. Further collaborative work is strongly recommended and should include more detailed isolation of intervals in wells by multi-packer installations, to better determine the geochemical and hydrological characteristics of the Karachai-Mishelyak system; deployment of a broader soil water and soil sampling array; a more detailed examination of the distribution and concentration of radionuclides by high-resolution field gamma spectrometry; and a detailing of the area's electrical resistivity setting, using a mobile electromagnetic measurement system. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, BERKELEY, CA 94720 USA. MAYAK PROD ASSOC, CHELYABINSK 65, RUSSIA. PSA HYDROSPETZGEOL, MOSCOW, RUSSIA. US DOE, ENVIRONM MEASUREMENTS LAB, NEW YORK, NY 10014 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 8 TC 6 Z9 6 U1 1 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0177-5146 J9 ENVIRON GEOL JI Environ. Geol. PD FEB PY 1997 VL 29 IS 3-4 BP 216 EP 227 PG 12 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA WN751 UT WOS:A1997WN75100009 ER PT J AU Grossl, PR Eick, M Sparks, DL Goldberg, S Ainsworth, CC AF Grossl, PR Eick, M Sparks, DL Goldberg, S Ainsworth, CC TI Arsenate and chromate retention mechanisms on goethite .2. Kinetic evaluation using a pressure-jump relaxation technique SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ADSORPTION-DESORPTION; OXIDE MINERALS; PHOSPHATE; MODEL AB The kinetics of arsenate and chromate adsorption/desorption on goethite (alpha-FeOOH) were investigated using a pressure-jump (p-jump) relaxation technique, information provided by this technique was used to elucidate the fate of arsenate and chromate in natural environments. Chemical relaxations resulting from rapidly induced pressure changes were monitored via conductivity detection. The adsorption/desorption of these oxyanions on goethite involved a double relaxation event. The proposed mechanism far the adsorption of arsenate and chromate on goethite is a two-step process resulting in the formation of an inner-sphere bidentate surface complex. The first step, associated with the fast tau values, involved an initial ligand exchange reaction of aqueous oxyanion species H2AsO4- or HCrO4- with OH ligands at the goethite surface forming an inner-sphere monodentate surface complex. The subsequent step, associated with the slow tau values, involved a second ligand exchange reaction, resulting in the formation of an inner-sphere bidentate surface complex. Overall, the results suggest that chromate may be the more mobile of the two oxyanions in soil systems. C1 LOUISIANA STATE UNIV, CTR AGR, LOUISIANA AGR EXPT STN, DEPT AGRON, BATON ROUGE, LA 70803 USA. UNIV DELAWARE, DEPT PLANT & SOIL SCI, NEWARK, DE 19717 USA. USDA ARS, US SALIN LAB, RIVERSIDE, CA 92507 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Grossl, PR (reprint author), UTAH STATE UNIV, DEPT PLANTS SOILS & BIOMETEOROL, LOGAN, UT 84322 USA. NR 23 TC 230 Z9 245 U1 1 U2 40 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1997 VL 31 IS 2 BP 321 EP 326 DI 10.1021/es950654l PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WG343 UT WOS:A1997WG34300024 ER PT J AU Ingram, JC Groenewold, GS Appelhans, AD Delmore, JE Olson, JE Miller, DL AF Ingram, JC Groenewold, GS Appelhans, AD Delmore, JE Olson, JE Miller, DL TI Direct surface analysis of pesticides on soil, leaves, grass, and stainless steel by static secondary ion mass spectrometry SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ENVIRONMENTAL SURFACES; LEAF SURFACES; SIMS; EXTRACTION; PHOSPHATE; PARAQUAT; DIQUAT AB Direct surface analyses by static secondary ion mass spectrometry (SIMS) were performed far the following pesticides adsorbed on dandelion leaves, grass, soil, and stainless steel samples: alachlor, atrazine, captan, carbofuran, chlorpyrifos, chlorsulfuron, chlorthal-dimethyl, cypermethrin, 2,4-D, diuran, glyphosate, malathion, methomyl, methyl arsonic acid, mocap, norflurazon, oxyfluorfen, paraquat temik, and trifluralin. The purpose of this study was to evaluate static SIMS as a tool for pesticide analysis, principally for use in screening samples for pesticides. The advantage of direct surface analysis compared with conventional pesticide analysis methods is the elimination of sample pretreatment including extraction, which streamlines the analysis substantially; total analysis time for SIMS analysis was ca. 10 min/sample. Detection of 16 of the 20 pesticides on all four substrates was achieved. Of the remaining four pesticides, only one (trifluralin) was not detected on any of the samples. The minimum detectable quantity was determined for paraquat on soil in order to evaluate the efficacy of using SIMS as a screening tool. Paraquat was detected at 3 pg/mm(2) (ca. 0.005 monolayers). The results of these studies suggest that SIMS is capable of direct surface detection of a range of pesticides, with low volatility, polar pesticides being the mast easily detected. RP Ingram, JC (reprint author), IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 25 TC 28 Z9 31 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1997 VL 31 IS 2 BP 402 EP 408 DI 10.1021/es960213h PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WG343 UT WOS:A1997WG34300035 ER PT J AU Wolf, SF Bates, JK Buck, EC Dietz, NL Portner, JA Brown, NR AF Wolf, SF Bates, JK Buck, EC Dietz, NL Portner, JA Brown, NR TI Physical and chemical characterization of actinides in soil from Johnston Atoll SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID OXIDATION-STATE; PACIFIC-OCEAN; PLUTONIUM; RADIONUCLIDES; DISTRIBUTIONS AB Characterization of the actinide content of a sample of contaminated coral soil from Johnston Atoll, the site of three non-nuclear destructs of nuclear warhead-carrying THOR missiles in 1962, revealed that >99% of the total actinide content is associated with discrete bomb fragments. After removal of these fragments, there was an inverse correlation between actinide content and soil particle size in particles from 43 to 0.4 mu m diameter. Detailed analyses of this remaining soil revealed no discrete actinide phase in these soil particles, despite measurable actinide content. Observations indicate that exposure to the environment has caused the conversion of relatively insoluble actinide oxides to the more soluble actinyl oxides and actinyl carbonate coordinated complexes. This process has led to dissolution of actinides from discrete particles and migration to the surrounding soil surfaces, resulting in a dispersion greater than would be expected by physical transport of discrete particles alone. RP Wolf, SF (reprint author), ARGONNE NATL LAB,DIV CHEM TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Buck, Edgar/D-4288-2009; Buck, Edgar/N-7820-2013 OI Buck, Edgar/0000-0001-5101-9084 NR 26 TC 11 Z9 11 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1997 VL 31 IS 2 BP 467 EP 471 DI 10.1021/es960295+ PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WG343 UT WOS:A1997WG34300044 ER PT J AU Aggarwal, PK Fuller, ME Gurgas, MM Manning, JF Dillon, MA AF Aggarwal, PK Fuller, ME Gurgas, MM Manning, JF Dillon, MA TI Use of stable oxygen and carbon isotope analyses for monitoring the pathways and rates of intrinsic and enhanced in situ biodegradation SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIA; INSITU BIODEGRADATION; SANDY AQUIFER; FRACTIONATION; HYDROCARBONS; RESPIRATION; WATER; SOIL AB Significant challenges remain in developing reliable techniques to monitor in situ biodegradation. Stable carbon and oxygen isotope analyses of the contaminants, products of degradation, and electron acceptor(s) may provide robust means for monitoring the occurrence, pathways, and rates of intrinsic or enhanced in situ biodegradation. Results of a laboratory study using diesel fuel and a mixed microbial culture show that combined stable carbon isotope analyses of carbon dioxide and stable oxygen isotope analyses of molecular oxygen allow monitoring of the occurrence and pathways of degradation. The first-order rate constants far contaminant degradation (about -0.04 day(-1)) obtained from oxygen and contaminant concentrations are in excellent agreement with those obtained from isotopic data for oxygen (-0.04 to -0.05 day(-1)), indicating that oxygen isotope analyses of molecular oxygen can be used for quantifying the rate of contaminant degradation. Based on our results and a review of the published literature on oxygen isotope systematics of molecular oxygen and other common electron accepters (nitrate and sulfate), it is suggested that combined carbon and oxygen isotope analyses of carbon dioxide and the electron accepters provide effective toots far monitoring intrinsic and enhanced in situ biodegradation of fuel or chlorinated hydrocarbons under aerobic and anaerobic conditions. RP Aggarwal, PK (reprint author), ARGONNE NATL LAB, DIV ENVIRONM RES, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI aggarwal, pradeep/C-8367-2016 OI aggarwal, pradeep/0000-0001-5970-1408 NR 34 TC 48 Z9 49 U1 1 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1997 VL 31 IS 2 BP 590 EP 596 DI 10.1021/es960562b PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WG343 UT WOS:A1997WG34300062 ER PT J AU McCreedy, CD Jagoe, CH Glickman, LT Brisbin, IL AF McCreedy, CD Jagoe, CH Glickman, LT Brisbin, IL TI Bioaccumulation of cesium-137 in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned nuclear reactor reservoir SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE bioaccumulation; yellow bullhead catfish; radiocesium; size-effect; Richards model ID TROUT SALMO-TRUTTA; BROWN TROUT; COOLING RESERVOIR; FRESH-WATER; RADIOCESIUM; CHERNOBYL; FISH; LAKE; GROWTH; ACCUMULATION AB Bioaccumulation of Cs-137 was investigated in yellow bullhead catfish (Ameiurus natalis) inhabiting an abandoned reactor reservoir, Pond B, Savannah River Site, Barnwell Co., South Carolina. We collected fish by trap-netting, and determined ages from pectoral spines. Muscle and other tissues were assayed for Cs-137 by NaI-scintillation. Muscle Cs-137 was unrelated to sex (p = 0.859) or mass of fish (p = 0.224), but was related to age (p = 0.036). Examination of least-squares means suggested that Cs-137 in muscle increased up to about age 3, but did not increase with greater age (means for 1, 2, 3, 3, 5, and 6 year olds were 2,630, 3,011, 3,513, 3,417, 3,599, and 3,339 Bq/kg, respectively). A modified Richards model showed equilibrium Cs-137 concentration in muscle (3,625 Bq/kg) was acquired in approximately 2.4 years. Growth differed between sexes (p < 0.001), and the time to asymptotic body mass was longer than the time to attain equilibrium Cs-137 concentration. Males attained an asymptotic mass of 577 g in approximately 6.3 years; females attained an asymptotic mass of 438 g in approximately 5.9 years. The cumulative Cs-137 burden of the population was 4.9 x 10(6) Bq, representing <0.001% of the Cs-137 inventory of the reservoir. Concentration of Cs-137 varied among tissues (p < 0.001), with gill and muscle the lowest and highest (634 and 3,712 Bq/kg, respectively). Concentration of (CS)-C-137 in ovaries declined with increasing ovary mass (p = 0.001; r(2) = 0.60). Until equilibrium is attained in these fish, Cs-137 concentration is directly related to increasing age rather than size. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP McCreedy, CD (reprint author), PURDUE UNIV,SCH VET MED,DEPT VET PATHOBIOL,W LAFAYETTE,IN 47907, USA. NR 45 TC 15 Z9 15 U1 1 U2 6 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD FEB PY 1997 VL 16 IS 2 BP 328 EP 335 DI 10.1897/1551-5028(1997)016<0328:BOCIYB>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WK824 UT WOS:A1997WK82400031 ER PT J AU Kszos, LA Stewart, AJ Sumner, JR AF Kszos, LA Stewart, AJ Sumner, JR TI Evidence that variability in ambient fathead minnow short-term chronic tests is due to pathogenic infection SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE ambient toxicity testing; pathogen; fathead minnow ID CERIODAPHNIA-DUBIA; PIMEPHALES-PROMELAS; TOXICITY; STREAM AB An examination of results from ambient fathead minnow subchronic toxicity tests identified a common characteristic of the tests, which manifests itself as a large among-replicate and between-test variance in survival. The unusual replicate-specific mortality in tests with ambient water appears to be due to pathogenic bacteria or fungi. This finding is based on the following facts: a comparison of survival among replicates in effluents and ambient waters showed that when mean survival was low (40-70%), among-replicate variation for ambient tests was greater than it was for the effluent tests; in 63 tests conducted at three locations over nearly 3 years, treating the water with ultraviolet (UV) light improved survival; a seasonal pattern to survival was present at ambient sites; survival was higher when minnows were separated by using 1 minnow/beaker rather than the standard system of 10 minnows/beaker; and survival tended to be higher in ambient sites contaminated with low levels of chlorine. The existence of the pathogen(s) does not mean that the test cannot be used effectively to assess toxicity of ambient waters; instead, it indicates that factors other than toxicity may need to be taken into consideration when interpreting the results. C1 CKY ENVIRONM SERV INC,OAK RIDGE,TN 37830. RP Kszos, LA (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. OI Kszos, Lynn/0000-0002-8218-9032; stewart, arthur/0000-0003-1968-5997 NR 23 TC 12 Z9 12 U1 0 U2 0 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD FEB PY 1997 VL 16 IS 2 BP 351 EP 356 DI 10.1897/1551-5028(1997)016<0351:ETVIAF>2.3.CO;2 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WK824 UT WOS:A1997WK82400034 ER PT J AU Wang, GJ Volkow, ND Hitzemann, RJ Wong, C Angrist, B Burr, G Pascani, K Pappas, N Lu, A Cooper, T Lieberman, JA AF Wang, GJ Volkow, ND Hitzemann, RJ Wong, C Angrist, B Burr, G Pascani, K Pappas, N Lu, A Cooper, T Lieberman, JA TI Behavioral and cardiovascular effects of intravenous methylphenidate in normal subjects and cocaine abusers SO EUROPEAN ADDICTION RESEARCH LA English DT Article DE methylphenidate; behavior; cardiovascular effect; cocaine ID RHESUS-MONKEY; METABOLISM; RECEPTORS; INJECTION; HUMANS; RAT AB This study compares the behavioral and cardiovascular response to methylphenidate (0.5 mg i.v.) in 10 cocaine abusers and 20 controls. Methylphenidate induced a long-lasting increase in blood pressure and pulse rate in both groups of subjects. It also induced a short-lasting 'high' (27 min) and longer-lasting 'restlessness' (67 min). In the normal subjects, but not in the cocaine abusers, methylphenidate significantly increased sexual desire and induced a subjective experience of 'loss of control'. In the cocaine abusers, methylphenidate consistently induced cocaine craving. While 90% of the cocaine abusers reported methylphenidate as pleasurable, only 50%, of the normal subjects did. Cocaine abusers reported that the 'high' induced by methylphenidate was similar to that of cocaine but lasted longer and was associated with more physical effects. C1 SUNY STONY BROOK,DEPT RADIOL,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. VET ADM MED CTR,DEPT PSYCHIAT,NORTHPORT,NY 11768. NYU,DEPT PSYCHIAT,NEW YORK,NY 10016. ALBERT EINSTEIN COLL MED,LONG ISL JEWISH MED CTR,DEPT PSYCHIAT,GLEN OAKS,NY. RP Wang, GJ (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 25 TC 50 Z9 51 U1 3 U2 4 PU KARGER PI BASEL PA ALLSCHWILERSTRASSE 10, CH-4009 BASEL, SWITZERLAND SN 1022-6877 J9 EUR ADDICT RES JI Eur. Addict. Res. PD FEB PY 1997 VL 3 IS 1 BP 49 EP 54 PG 6 WC Substance Abuse; Psychiatry SC Substance Abuse; Psychiatry GA XK964 UT WOS:A1997XK96400008 ER PT J AU Straughan, B Walker, DW AF Straughan, B Walker, DW TI Multi-component diffusion and penetrative convection SO FLUID DYNAMICS RESEARCH LA English DT Article ID FLUID LAYER; NONLINEAR STABILITY; CHEMISTRY; TRANSPORT; MAXIMUM; SYSTEM; MODEL; ONSET AB The problem is the investigation of penetrative thermal convection in a three constituent fluid. The stability criteria are derived by a Chebyshev tau method. Very interesting neutral curves are derived including non-perfect ''heart shaped'' oscillatory curves affording a variety of complex dynamical behaviour, and an isolated oscillatory curve allowing stability in distinct finite regions of the Rayleigh number space. When the penetration effect is increased the closed oscillatory curves become more skew and for certain parameters it is found that the closed curve has the same minimum critical Rayleigh number as the unbounded stationary convection one. This leads to the novel prediction that different types of instability will occur at the same critical Rayleigh number but for different wave numbers. The behaviour of the growth rate is investigated to some extent and we see that an exchange of stabilities is occurring between the leading group of eigenvalues (i.e. the growth rate) whereby the eigenvalue with greatest real part may be a complex conjugate pair which is ''overtaken'' by a purely real eigenvalue in a suitable part of the Rayleigh number domain. C1 OAK RIDGE NATL LAB,MATH SCI SECT,OAK RIDGE,TN 37831. RI Walker, David/B-7978-2010; OI Walker, David/0000-0002-1360-6330 NR 25 TC 22 Z9 22 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-5983 J9 FLUID DYN RES JI Fluid Dyn. Res. PD FEB 1 PY 1997 VL 19 IS 2 BP 77 EP 89 DI 10.1016/S0169-5983(96)00031-7 PG 13 WC Mechanics; Physics, Fluids & Plasmas SC Mechanics; Physics GA WB330 UT WOS:A1997WB33000002 ER PT J AU Keeland, BD Conner, WH Sharitz, RR AF Keeland, BD Conner, WH Sharitz, RR TI A comparison of wetland tree growth response to hydrologic regime in Louisiana and South Carolina SO FOREST ECOLOGY AND MANAGEMENT LA English DT Article DE flooding; hydrologic regime; Louisiana; South Carolina; tree growth; USA ID FLOODING REGIMES; CYPRESS SWAMP; BALD-CYPRESS; DYNAMICS; FLORIDA; FOREST; PLANT; SOIL; ADAPTATIONS; VEGETATION AB Numerous investigations have examined the growth of wetland tree species under a variety of hydrologic conditions, Most studies have compared flooded versus non-flooded conditions in greenhouses or in one to a few field sites near each other or within the same region. Comparisons of wetland tree growth among widely separated areas of the country are rare, This study compared the diameter growth of Nyssa sylvatica var. biflora, Nyssa aquatica, and Taxodium distichum trees from Louisiana (Gulf Coastal Plain) and South Carolina (Atlantic Coastal Plain). In both regions, individual trees were distributed along a gradient of hydrologic regimes from infrequent to permanent flooding, Nyssa sylvatica var. biflora was restricted to periodically flooded sites in both regions. Within these sites, this species showed little response to differences in mean water depth. In contrast, significant differences among hydrologic regimes were detected for N. aquatica in both regions. In Louisiana, patterns of growth response did not correlate with the gradient of hydrologic regimes, but in South Carolina maximum growth was inversely related to mean water levels during the growing season. Maximum growth of T. distichum trees was observed at sites with shallow, permanent flooding in both regions. C1 BARUCH FOREST SCI INST,GEORGETOWN,SC 29442. SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. RP Keeland, BD (reprint author), NATL BIOL SURVEY,SO SCI CTR,700 CAJUNDOME BLVD,LAFAYETTE,LA 70506, USA. NR 68 TC 24 Z9 24 U1 2 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1127 J9 FOREST ECOL MANAG JI For. Ecol. Manage. PD FEB PY 1997 VL 90 IS 2-3 BP 237 EP 250 DI 10.1016/S0378-1127(96)03901-1 PG 14 WC Forestry SC Forestry GA WP680 UT WOS:A1997WP68000014 ER PT J AU Burakovsky, L AF Burakovsky, L TI Towards resolution of the scalar meson nonet enigma SO FOUNDATIONS OF PHYSICS LA English DT Article ID RESONANCE; NARROW; MODEL; FORCES AB By the application of a linear mass spectrum to a composite system of both the pseudoscalar and scalar meson nonets, we find three relations for the masses of the scalar states which suggest the q (q) over bar assignment for the scalar meson nonet a(0)(1320), K-0*(1430), f(0)(1500), and f(0)'(980). RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,LOS ALAMOS,NM 87545, USA. NR 51 TC 5 Z9 5 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0015-9018 J9 FOUND PHYS JI Found. Phys. PD FEB PY 1997 VL 27 IS 2 BP 315 EP 330 DI 10.1007/BF02550457 PG 16 WC Physics, Multidisciplinary SC Physics GA WV626 UT WOS:A1997WV62600012 ER PT J AU Burakovsky, L Horwitz, LP AF Burakovsky, L Horwitz, LP TI Mass spectrum of a baryon octet is linear SO FOUNDATIONS OF PHYSICS LETTERS LA English DT Article DE hadronic resonance spectrum; Gell-Mann-Okubo AB It is argued that the mass spectrum of a baryon octet is linear, consistent with a Gell-Mann-Okubo type relation for the squared masses of the baryons obtained previously be Balazs and Nicolsecu. The mass spectrum of a baryon decuplet is briefly discussed. C1 INST ADV STUDY,SCH NAT SCI,PRINCETON,NJ 08540. BAR ILAN UNIV,DEPT PHYS,RAMAT GAN,ISRAEL. RP Burakovsky, L (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,LOS ALAMOS,NM 87545, USA. NR 26 TC 6 Z9 6 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0894-9875 J9 FOUND PHYS LETT JI Found. Phys. Lett. PD FEB PY 1997 VL 10 IS 1 BP 61 EP 71 DI 10.1007/BF02764120 PG 11 WC Physics, Multidisciplinary SC Physics GA WV627 UT WOS:A1997WV62700005 ER PT J AU Koetsier, P McArthur, JV Leff, LG AF Koetsier, P McArthur, JV Leff, LG TI Spatial and temporal response of stream bacteria to sources of dissolved organic carbon in a blackwater stream system SO FRESHWATER BIOLOGY LA English DT Article ID PRAIRIE STREAM; CHEMICAL-COMPOSITION; LEAF DECOMPOSITION; WOODLAND STREAM; LEAVES; ECOSYSTEMS; PATTERNS; MATTER; FRESH; RIVER AB 1. We hypothesized that changes in bacterial colony growth would be correlated to shifts in riparian vegetation (via leachate quality) along a river continuum of a south-eastern, blackwater stream (U.S.A.). Spatially, we expected bacterial assemblages from downstream reaches to utilize more sources of leachate and at higher concentrations than bacteria collected from headwater reaches. Temporally, we predicted higher colony growth on leachate from autumn-shed (senescent) leaves compared with leachate from fresh, green leaves. 2. We examined spatial differences in assemblage growth by culturing bacteria sampled along the stream continuum on gradient plates using leachates from four common riparian species (Taxodium distichum, Carya spp., Acer rubrum and Decumaria barbara). Bacteria from the lowest site were able to use all sources provided and at all concentrations, whereas bacteria from upper reaches could not. Colony density was correlated to relative leachate concentration at all sites along the continuum. 3. Leachates from fresh and senescent A. rubrum leaves were used to determine temporal differences. Winter assemblages of bacteria could not grow on fresh leaf leachate at any concentration but grew well on autumn leaf leachate at higher concentrations. Differential response of bacterial assemblages indicated local adaptation to potential sources of dissolved organic matter. 4. Growth response of stream bacterial colonies appeared to be dependent on the timing and source of leachate as well as on sources of dissolved organic carbon from further upstream. Growth of bacterial assemblages exhibited 'generalist' characteristics in headwater reaches and 'specialist' characteristics at the mouth of our study stream drainage. Thus, our findings lend support to the argument that variable resource habitats favour a small, generalist assemblage, while environments with stable resource supplies allow for highly diverse assemblages dominated by specialists. C1 SAVANNAH RIVER ECOL LAB,DIV WETLAND ECOL,AIKEN,SC 29802. NR 42 TC 35 Z9 36 U1 1 U2 10 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0046-5070 J9 FRESHWATER BIOL JI Freshw. Biol. PD FEB PY 1997 VL 37 IS 1 BP 79 EP 89 DI 10.1046/j.1365-2427.1997.d01-535.x PG 11 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA WJ192 UT WOS:A1997WJ19200006 ER PT J AU Kaufman, PD Kobayashi, R Stillman, B AF Kaufman, PD Kobayashi, R Stillman, B TI Ultraviolet radiation sensitivity and reduction of telomeric silencing Saccharomyces cerevisiae cells lacking chromatin assembly factor-I SO GENES & DEVELOPMENT LA English DT Article DE nucleosome; DNA damage; heterochromatin; DNA replication ID DNA-REPLICATION INVITRO; MATING LOCI; FREE SYSTEM; HISTONE H4; YEAST; TRANSCRIPTION; PROTEIN; REPRESSION; NUCLEAR; ORIGIN AB In vivo, nucleosomes are formed rapidly on newly synthesized DNA after polymerase passage. Previously, a protein complex from human cells, termed chromatin assembly factor-I (CAF-I), was isolated that assembles nucleosomes preferentially onto SV40 DNA templates that undergo replication in vitro. Using a similar assay, we now report the purification of CAF-I from the budding yeast Saccharomyces cerevisiae. Amino acid sequence data from purified yeast CAF-I led to identification of the genes encoding each subunit in the yeast genome data base. The CAC1 and CAC2 (chromatin assembly complex) genes encode proteins similar to the p150 and p60 subunits of human CAF-I, respectively. The gene encoding the p50 subunit of yeast CAF-I (CAC3) is similar to the human p48 CAF-I subunit and was identified previously as MSI1, a member of a highly conserved subfamily of WD repeat proteins implicated in histone function in several organisms. Thus, CAP-I has been conserved functionally and structurally from yeast to human cells. Genes encoding the CAF-I subunits (collectively referred to as CAC genes) are not essential for cell viability. However, deletion of any CAC gene causes an increase in sensitivity to ultraviolet radiation, without significantly increasing sensitivity to gamma rays. This is consistent with previous biochemical data demonstrating the ability of CAF-I to assemble nucleosomes on templates undergoing nucleotide excision repair. Deletion of CAC genes also strongly reduces silencing of genes adjacent to telomeric DNA; the CAC1 gene is identical to RLF2 (Rap1p localization factor-2), a gene required for the normal distribution of the telomere-binding Raplp protein within the nucleus. Together, these data suggest that CAF-I plays a role in generating chromatin structures in vivo. C1 COLD SPRING HARBOR LAB,COLD SPRING HARBOR,NY 11724. UNIV CALIF BERKELEY,DEPT MOL & CELL BIOL,BERKELEY,CA 94720. RP Kaufman, PD (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. OI Stillman, Bruce/0000-0002-9453-4091 FU NCI NIH HHS [CA 13106] NR 59 TC 282 Z9 287 U1 1 U2 1 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 0890-9369 J9 GENE DEV JI Genes Dev. PD FEB 1 PY 1997 VL 11 IS 3 BP 345 EP 357 DI 10.1101/gad.11.3.345 PG 13 WC Cell Biology; Developmental Biology; Genetics & Heredity SC Cell Biology; Developmental Biology; Genetics & Heredity GA WH817 UT WOS:A1997WH81700006 PM 9030687 ER PT J AU Marker, PC Seung, KJ Bland, AE Russell, LB Kingsley, DM AF Marker, PC Seung, KJ Bland, AE Russell, LB Kingsley, DM TI Spectrum of Bmp5 mutations from germline mutagenesis experiments in mice SO GENETICS LA English DT Article ID ETHYL-N-NITROSOUREA; FACTOR-BETA SUPERFAMILY; MOLECULAR ANALYSIS; TRANSFORMING GROWTH-FACTOR-BETA-2; DROSOPHILA-MELANOGASTER; CRYSTAL-STRUCTURE; ESCHERICHIA-COLI; SPLICE JUNCTIONS; MURINE HOMOLOG; B6C3F(1) MICE AB Over 40 years of mutagenesis experiments using the mouse specific-locus test have produced a large number of induced germline mutations at seven loci, among them the short ear locus. We have previously shown that the short ear locus encodes bone morphogenetic protein 5 (BMP5), a member of a large family of secreted signaling molecules that play key roles in axis formation, tissue differentiation, mesenchymal epithelial interactions, and skeletal development. Here we examine 24 chemical- and radiation-induced mutations at the short ear locus. Sequence changes in the Bmp5 open reading frame confirm the importance of cysteine residues in the function of TGF beta superfamily members. The spectrum of N-ethyl-N nitrosourea-induced mutations also provides new information about the basepair, sequence context, and strand specificity of germline mutations in mammals. C1 STANFORD UNIV, SCH MED, BECKMAN CTR B300, DEPT DEV BIOL, PALO ALTO, CA 94304 USA. OAK RIDGE NATL LAB, DIV BIOL, OAK RIDGE, TN 37831 USA. FU NIEHS NIH HHS [1-Y01-ES-50318-00] NR 54 TC 40 Z9 40 U1 1 U2 4 PU GENETICS SOCIETY AMERICA PI BETHESDA PA 9650 ROCKVILLE AVE, BETHESDA, MD 20814 USA SN 0016-6731 EI 1943-2631 J9 GENETICS JI Genetics PD FEB PY 1997 VL 145 IS 2 BP 435 EP 443 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA WM599 UT WOS:A1997WM59900019 PM 9071596 ER PT J AU Paterson, BA Riciputi, LR McSween, HY AF Paterson, BA Riciputi, LR McSween, HY TI A comparison of sulfur isotope ratio measurement using two ion microprobe techniques and application to analysis of troilite in ordinary chondrites SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID HIGH-PRECISION; MICROANALYSIS; METEORITES; SULFIDES; MINERALS AB Continual improvements in the precision of isotope ratio measurements made by ion microprobe, and the attempt to resolve smaller isotopic differences using this technique means that it is increasingly important to demonstrate the accuracy of calibration of this method, particularly when it is impossible to mount a standard with the unknown being analyzed. An assessment of the accuracy and precision using ion microprobe methods for the measurement of isotope ratios is made analyzing a pyrite standard mounted in several thin sections and troilite in ordinary chondrite meteorites. We compare two methods, the traditional high mass resolution approach and the more recent extreme energy filtering technique. The results indicate that both techniques offer precise measurements for analyses made within a single thin-section. However, the accuracy of the high mass resolution results are significantly worse than those obtained using extreme energy filtering when a standard cannot be mounted with the unknown. For analysis of a standard pyrite mounted in different thin sections, the measured instrumental mass bias varied by up to 7 parts per thousand. Analysis of the same samples using extreme energy filtering showed no variation in instrumental mass bias within 0.5 parts per thousand. Similar results were observed in analysis of troilite. Whereas the extreme energy filtering results are within error of the expected 0 parts per thousand, values obtained using high mass resolution differ by up to ?+/-3 parts per thousand. Our results indicate that it is possible to analyze delta(34)S values in sulfides using an ion microprobe with precision and accuracy of +/-0.25 parts per thousand(1 sigma) in 12 min, with a spatial resolution under 20 mu m. Copyright (C) 1997 Elsevier Science Ltd. C1 UNIV TENNESSEE,DEPT GEOL SCI,KNOXVILLE,TN 37996. RP Paterson, BA (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831, USA. NR 28 TC 25 Z9 26 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD FEB PY 1997 VL 61 IS 3 BP 601 EP 609 DI 10.1016/S0016-7037(96)00353-5 PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WK514 UT WOS:A1997WK51400009 ER PT J AU Lewis, AJ Palmer, MR Sturchio, NC Kemp, AJ AF Lewis, AJ Palmer, MR Sturchio, NC Kemp, AJ TI The rare earth element geochemistry of acid-sulphate and acid-sulphate-chloride geothermal systems from Yellowstone National Park, Wyoming, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID PLATEAU VOLCANIC FIELD; MID-ATLANTIC RIDGE; HYDROTHERMAL FLUIDS; AQUEOUS GEOCHEMISTRY; RHYOLITIC MAGMA; NATURAL-WATERS; MOBILITY; REE; FRACTIONATION; SPECIATION AB Rare earth element (REE) concentrations have been determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) in acid-sulphate and acid-sulphate-chloride waters and the associated sinters and volcanic rocks from the Yellowstone National Park(YNP), Wyoming, USA, geothermal system. REE concentrations in the volcanic rocks range from 222 to 347 ppm; their chondrite-normalised REE patterns are typical of upper continental crust, with LREE > HREE and negative Eu anomalies. Total REE concentrations in the fluids range from 3 to 1133 nmol kg(-1) (greater than or equal to 162 ppm), and Sigma REE concentrations in sinter are greater than or equal to 181 ppm. REE abundances and patterns in drill core material from YNP indicate some REE mobility. Normalisation of REE concentrations in altered Lava Creek Tuff (LCT) from Y-12 drill core to REE concentrations in fresh LCT indicate that the REE overall have been depleted with the exception of Eu, which has been decoupled from the REE series and concentrated in the altered rocks. Relative to the host rocks the REE patterns of the fluids are variably depleted in HREEs and LREEs, and usually have a pronounced positive Eu anomaly. This decoupling of Eu from the REE suite suggests that (1) Eu has been preferentially removed either from the host rock glass or from the host rock minerals, or (2) the waters are from a high temperature or reducing environment where Eu2+ is more soluble than the trivalent REEs. Since the latter is inconsistent with production of acid-sulphate springs in a low temperature, oxidising near-surface environment, we suggest that the positive Eu anomalies in the fluids result from preferential dissolution of a Eu-rich phase in the host rock. Spatial and temporal variations in major element chemistry and pH of the springs sampled from Norris Geyser Basin and Crater Hills accompany variations in REE concentrations and patterns of individual geothermal springs. These are possibly related to changes in subsurface plumbing, which results in variations in mixing and dilution of the geothermal fluids and may have lead to changes in the extent and nature of REE complexing. Copyright (C) 1997 Elsevier Science Ltd. C1 UNIV BRISTOL, DEPT GEOL, BRISTOL BS8 1RJ, AVON, ENGLAND. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. RI Palmer, Martin/I-6765-2012 OI Palmer, Martin/0000-0003-1660-3714 NR 37 TC 82 Z9 87 U1 0 U2 20 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 EI 1872-9533 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD FEB PY 1997 VL 61 IS 4 BP 695 EP 706 DI 10.1016/S0016-7037(96)00384-5 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WN031 UT WOS:A1997WN03100001 ER PT J AU Granger, DE Kirchner, JW Finkel, RC AF Granger, DE Kirchner, JW Finkel, RC TI Quaternary downcutting rate of the New River, Virginia, measured from differential decay of cosmogenic Al-26 and Be-10 in cave-deposited alluvium SO GEOLOGY LA English DT Article ID UPLIFT RATES; HALF-LIFE; QUARTZ AB The concentrations of the cosmogenic radionuclides Al-26 and Be-10 in quartz can be used to date sediment burial, Here we use Al-26 and Be-10 in cave-deposited river sediment to infer the time of sediment emplacement. Sediment burial dates from a vertical sequence of caves along the New River constrain its Quaternary downcutting rate to 27.3 +/- 4.5 m/m.y. and may provide evidence of regional tectonic tilt. C1 LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550. RP Granger, DE (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. RI Kirchner, James/B-6126-2009 OI Kirchner, James/0000-0001-6577-3619 NR 32 TC 120 Z9 135 U1 1 U2 14 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD FEB PY 1997 VL 25 IS 2 BP 107 EP 110 DI 10.1130/0091-7613(1997)025<0107:QDROTN>2.3.CO;2 PG 4 WC Geology SC Geology GA WG663 UT WOS:A1997WG66300003 ER PT J AU Newman, GA Alumbaugh, DL AF Newman, GA Alumbaugh, DL TI Three-dimensional massively parallel electromagnetic inversion .1. Theory SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE electromagnetic modelling; inversion; tomography ID CONJUGATE GRADIENTS AB An iterative solution to the non-linear 3-D electromagnetic inverse problem is obtained by successive linearized model updates using the method of conjugate gradients. Full wave equation modelling for controlled sources is employed to compute model sensitivities and predicted data in the frequency domain with an efficient 3-D finite-difference algorithm. Necessity dictates that the inverse be underdetermined, since realistic reconstructions require the solution for tens of thousands of parameters. In addition, large-scale 3-D forward modelling is required and this can easily involve the solution of over several million electric field unknowns per solve. A massively parallel computing platform has therefore been utilized to obtain reasonable execution times, and results are given for the 1840-node Intel Paragon. The solution is demonstrated with a synthetic example with added Gaussian noise, where the data were produced from an integral equation forward-modelling code, and is different from the finite difference code embedded in the inversion algorithm. RP Newman, GA (reprint author), SANDIA NATL LABS, DEPT GEOPHYS, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Newman, Gregory/G-2813-2015 NR 17 TC 95 Z9 103 U1 1 U2 7 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD FEB PY 1997 VL 128 IS 2 BP 345 EP 354 DI 10.1111/j.1365-246X.1997.tb01559.x PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WG096 UT WOS:A1997WG09600007 ER PT J AU Alumbaugh, DL Newman, GA AF Alumbaugh, DL Newman, GA TI Three-dimensional massively parallel electromagnetic inversion .2. Analysis of a crosswell electromagnetic experiment SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE borehole geophysics; electromagnetic modelling; electromagnetic surveys; inversion; tomography ID TOMOGRAPHY AB A 3-D electromagnetic inversion scheme has been successfully applied to crosswell electromagnetic data collected at the Richmond Field Station near Berkeley, California. By comparing images of data collected before and after the injection of 50 000 gallons of salt water, a 3-D image of the plume has been developed, which shows the location of zones of maximum permeability surrounding the injection well through which the salt water has migrated. A resolution analysis has determined that the location of the plume is fairly accurate. However, the image of the geology will be distorted due to incomplete data coverage. This latter problem is further complicated by the fact that data residuals indicate that the wells deviate from the vertical. These deviations have been shown to cause artefacts within the images and thus further reduce the accuracy of the images with respect to the geology. RP Alumbaugh, DL (reprint author), SANDIA NATL LABS,DEPT GEOPHYS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Newman, Gregory/G-2813-2015 NR 8 TC 44 Z9 47 U1 0 U2 6 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD FEB PY 1997 VL 128 IS 2 BP 355 EP 363 DI 10.1111/j.1365-246X.1997.tb01560.x PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WG096 UT WOS:A1997WG09600008 ER PT J AU Gosling, JT Bame, SJ Feldman, WC McComas, DJ Riley, P Goldstein, BE Neugebauer, M AF Gosling, JT Bame, SJ Feldman, WC McComas, DJ Riley, P Goldstein, BE Neugebauer, M TI The northern edge of the band of solar wind variability: Ulysses at -4.5 AU SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERACTION REGIONS; PLASMA AB Ulysses observations reveal that the northern edge of the low-latitude band of solar wind variability at similar to 4.5 AU was located at N30 degrees in the latter part of 1996 when solar activity was at a minimum. This edge latitude is intermediate between edge latitudes found during previous encounters with the band edge along different portions of Ulysses' polar orbit about the Sun. Corotating interaction regions, CIRs, near the northern edge of the band were tilted in such a manner that the forward and reverse shocks bounding the CIRs were propagating equatorward and poleward, respectively, providing definite confirmation that CIRs have opposed tilts in the opposite solar hemispheres. No shocks or coronal mass ejections, CMEs, were detected during the similar to 1.5 y traverse of the northern, high-latitude northern hemisphere; however, al the northern edge of the band of variability an expanding CME was observed that was driving a shock into the high-speed wind. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Gosling, JT (reprint author), LOS ALAMOS NATL LAB,MS D466,LOS ALAMOS,NM 87545, USA. NR 12 TC 42 Z9 42 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1997 VL 24 IS 3 BP 309 EP 312 DI 10.1029/97GL00001 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WG511 UT WOS:A1997WG51100027 ER PT J AU Heiken, G Nielson, DL Lawrence, RP AF Heiken, G Nielson, DL Lawrence, RP TI Continental drilling SO GEOTIMES LA English DT Article RP Heiken, G (reprint author), LOS ALAMOS NATL LAB,EES-1,MS D462,LOS ALAMOS,NM 87545, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD FEB PY 1997 VL 42 IS 2 BP 57 EP 58 PG 2 WC Geosciences, Multidisciplinary SC Geology GA WF545 UT WOS:A1997WF54500065 ER PT J AU Durbin, PW Kullgren, B Schmidt, CT AF Durbin, PW Kullgren, B Schmidt, CT TI Circulatory kinetics of intravenously injected Pu-238(IV) citrate and C-14-CaNa3-DTPA in mice: Comparison with rat, dog, and reference man SO HEALTH PHYSICS LA English DT Article DE plutonium; Ca-DTPA; biokinetics; blood ID SEQUESTERING AGENTS; ACTINIDES; LIGANDS; REMOVAL; CHELATION; RETENTION; PLUTONIUM; DTPA AB New ligands for in vivo chelation of Pu(IV) are being synthesized and evaluated in mice for efficacy and toxicity. Biokinetic studies of the new ligands, CaNa3-DTPA, and Pu(IV) are major components of those investigations. Young adult female mice were injected intravenously (iv) with H-3-inulin, C-14-CaNa3-DTPA, or Pu-238(IV) citrate to provide baseline data for plasma clearance, tissue uptake, and excretion rates and to determine the dilution volume (VOD) and renal clearance rate (RC) of filterable substances. Published plasma clearance data for iv-injected C-14-CaNa3-DTPA and Pu(IV) citrate in Reference Man, dog, and rat were collected. Based on combined data for H-3-inulin and C-14-CaNa3-DTPA, VOD = 17% of body weight and RC = 18 mL kg(-1) min(-1) for mice. Retention of C-14-CaNa3-DTPA in the four species is proportional to body weight and inversely proportional to RC: Integrals of the retention of C-14-CaNa3-DTPA from R(t) = 1.0 to R(t) = 0.05 are 108, 43, 28, and 10 DF min, respectively, for Reference Man, dog, rat, and mouse. Clearances of iv-injected Pu(IV) citrate from plasma are in the same order: The plasma curve integrals from injection to 1440 min are 840, 640, 280, and 67 DF min, respectively, for Reference Man, dog, rat, and mouse. In mice, a large fraction of newly injected Pu(IV) is rapidly transferred to the interstitial water of bulk soft tissue (excluding liver and kidneys), from which it is cleared at the same rate as from the plasma. Rapid plasma clearance, escape into interstitial water (22% ID at 20 min), significant early urinary excretion (8% ID in 12 h), and prompt deposition in liver and skeleton (complete in 12 h) are evidence of inefficient binding to plasma protein (mainly transferrin) of newly injected Pu(IV) in mice. Conversely, slow plasma clearance, little early urinary excretion, and delayed deposition in liver and skeleton reflect more efficient binding by transferrin of newly injected Pu(IV) in Reference Man and dog. Pharmacokinetic parameters (effective dosage, effective concentration) of CaNa3-DTPA, alone or combined with plasma Pu(IV) integrals, yielded only qualitative predictions of the relative efficacies of CaNa3-DTPA therapy in four species. The need for improved models of Pu(IV) and ligand biokinetics and the suitability of the three animals for predicting chelation therapy outcomes in humans are discussed. C1 UNIV CALIF BERKELEY, ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB, DIV CHEM SCI, BERKELEY, CA 94720 USA. FU NIEHS NIH HHS [ES 02698] NR 39 TC 22 Z9 22 U1 0 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD FEB PY 1997 VL 72 IS 2 BP 222 EP 235 DI 10.1097/00004032-199702000-00005 PG 14 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WE857 UT WOS:A1997WE85700006 PM 9003707 ER PT J AU Sharma, N Hess, CT Thrall, KD AF Sharma, N Hess, CT Thrall, KD TI A compartmental model of water radon contamination in the human body SO HEALTH PHYSICS LA English DT Article DE radon; radioactivity, environmental; alpha particles; dose ID RN-222; INGESTION AB A multicompartmental model is developed to simulate the biokinetics in the human body following the ingestion of an inert gas. It was assumed that 100% of the radon ingested appears in the stomach, from which it is transported through the body to different organs via the blood stream. Each of these organs absorbs and releases radon differently, and, amongst all, the fat retains radon for the longest time. To test the model, the information on elimination rates of Rn-222 in expired breath was obtained from other experiments done at the University of Maine. The data included male and female participants with a wide range of ages and physical activity levels. The radiation doses in the different organs and tissues were computed. As was expected, the stomach sustained the maximum dose. In this study, the highest stomach dose to any volunteer was evaluated as 115 mSv y(-1). C1 UNIV MAINE, DEPT PHYS & ASTRON, ORONO, ME 04469 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 25 TC 11 Z9 11 U1 0 U2 1 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD FEB PY 1997 VL 72 IS 2 BP 261 EP 268 DI 10.1097/00004032-199702000-00009 PG 8 WC Environmental Sciences; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Environmental Sciences & Ecology; Public, Environmental & Occupational Health; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WE857 UT WOS:A1997WE85700010 PM 9003711 ER PT J AU Wright, TJ Ricke, DO Denison, K Abmayr, S Cotter, PD Hirschhorn, K Keinanen, M McDonaldMcGinn, D Somer, M Spinner, N YangFeng, T Zackai, E Altherr, MR AF Wright, TJ Ricke, DO Denison, K Abmayr, S Cotter, PD Hirschhorn, K Keinanen, M McDonaldMcGinn, D Somer, M Spinner, N YangFeng, T Zackai, E Altherr, MR TI A transcript map of the newly defined 165 kb Wolf-Hirschhorn syndrome critical region SO HUMAN MOLECULAR GENETICS LA English DT Article ID HUNTINGTON DISEASE GENE; PROTEIN-CODING REGIONS; INSITU HYBRIDIZATION; MENTAL-RETARDATION; HUMAN CHROMOSOME-4; CANDIDATE REGION; COSMID CLONES; SHORT ARM; SEQUENCE; DNA AB Wolf-Hirschhorn syndrome (WHS) is a multiple malformation syndrome characterised by mental and developmental defects resulting from the absence of a segment of one chromosome 4 short arm (4p16.3). Due to the complex and variable expression of this disorder, it is thought that the WHS is a contiguous gene syndrome with an undefined number of genes contributing to the phenotype, In an effort to identify genes that contribute to human development and whose absence results in this syndrome, we have utilised a series of landmark cosmids to characterise a collection of WHS patient derived cell lines. Fluorescence in situ hybridisation with these cosmids was used to refine the WHS critical region (WHSCR) to 260 kb, The genomic sequence of this region is available and analysis of this sequence through BLAST detected several cDNA clones in the dbEST data base, A total of nine independent cDNAs, and their predicted translation products, from this analysis Show no significant similarity to members of DNA or protein databases, Furthermore, these genes have been localised within the WHS critical region and reveal an interesting pattern of transcriptional organisation, A previously published report of a patient with proximal 4p- syndrome further refines the WHSCR to 165 kb defined by the loci D4S166 and D453327. This work provides the starting point to understand how multiple genes or other mechanisms can contribute to the complex phenotype associated with the Wolf-Hirschhorn syndrome. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,GENOM GRP,LOS ALAMOS,NM 87545. CUNY MT SINAI SCH MED,DEPT HUMAN GENET,NEW YORK,NY 10029. CUNY MT SINAI SCH MED,DEPT PEDIAT,NEW YORK,NY 10029. MEDIX CLIN LAB,FIN-02630 ESPOO,FINLAND. CHILDRENS HOSP,DEPT GENET,PHILADELPHIA,PA 19104. FAMILY FEDERAT FINLAND,DEPT MED GENET,FIN-00101 HELSINKI,FINLAND. YALE UNIV,DEPT GENET,NEW HAVEN,CT 06510. UNIV CALIF IRVINE,DEPT BIOL CHEM,IRVINE,CA 92717. NR 44 TC 136 Z9 136 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0964-6906 J9 HUM MOL GENET JI Hum. Mol. Genet. PD FEB PY 1997 VL 6 IS 2 BP 317 EP 324 DI 10.1093/hmg/6.2.317 PG 8 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA WH789 UT WOS:A1997WH78900020 PM 9063753 ER PT J AU Zamora, PO Bender, H Knapp, FFR Rhodes, BA Biersack, HJ AF Zamora, PO Bender, H Knapp, FFR Rhodes, BA Biersack, HJ TI Targeting peptides for pleural cavity tumor radiotherapy: Specificity and dosimetry of Re-188-RC-160 SO HYBRIDOMA LA English DT Article; Proceedings Paper CT III International Meeting on Idiotypic Network and Tumor Therapy by Gene Therapy, Drug Targeting, Vaccination, and Photodynamic Therapy - Immunological Approaches to Tumor Therapy CY FEB 29-MAR 02, 1996 CL BONN, GERMANY ID ANTIBODY-GUIDED IRRADIATION; SOMATOSTATIN ANALOG; MONOCLONAL-ANTIBODIES; THERAPY; CANCER AB Re-188-RC-160, a radiolabeled somatostatin analogue, is being explored for its potential as a local/regionally administered radiotherapeutic agent targeting somatostatin receptor-positive tumors, In studies in vitro and in vivo, Re-188-RC-160 was found to bind to somatostatin receptor-positive cells (NCI-H69, human small cell lung carcinoma), but not to binding-negative cells (Raji, Burkitt's lymphoma). The comparative binding of Re-188-labeled RC-160 [cyclic NH2-(D)-Phe-Cys-Try-(D)-Trp-Lys-Val-Cys-Trp-NH2] or CTOP [cyclic NH2(D)-Phe-Cys-Try-(D)-Trp-Orn-Thr-Pen-Thr-ol], a mu-opioid receptor antagonist used a negative control compound, was also determined in vitro and in vivo using NCI-H69 cells as targets. Re-188-RC-160 demonstrated higher net binding in vitro and in vivo compared to Re-188-RC-CTOP, and in vitro its binding could be reduced by excess unlabeled RC-160 whereas binding of Re-188-CTOP could not be reduced. Using another somatostatin receptor-positive human tumor line, ZR-75-1, a substantial amount of the cell-bound Re-188-RC-160 was found to be internalized, Dose estimates for Re-188-RC-160 in animals containing NCI-H69 tumors indicated that with three serial injections therapeutic doses greater than 60 Gy can be achieved. C1 UNIV BONN,KLIN NUKL MED,D-53127 BONN,GERMANY. RHOMED INC,ALBUQUERQUE,NM. OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN. NR 19 TC 6 Z9 6 U1 0 U2 1 PU MARY ANN LIEBERT INC PUBL PI LARCHMONT PA 2 MADISON AVENUE, LARCHMONT, NY 10538 SN 0272-457X J9 HYBRIDOMA JI Hybridoma PD FEB PY 1997 VL 16 IS 1 BP 85 EP 91 DI 10.1089/hyb.1997.16.85 PG 7 WC Biochemical Research Methods; Biotechnology & Applied Microbiology; Immunology SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Immunology GA WP297 UT WOS:A1997WP29700015 PM 9085134 ER PT J AU Riley, DJ Turner, CD AF Riley, DJ Turner, CD TI VOLMAX: A solid-model-based, transient volumetric Maxwell solver using hybrid grids SO IEEE ANTENNAS AND PROPAGATION MAGAZINE LA English DT Article DE transient analysis; FDTD methods; finite-element methods; finite-volume methods; time-domain analysis; numerical analysis ID DIFFERENCE TIME-DOMAIN; FINITE; EQUATIONS; FDTD RP Riley, DJ (reprint author), SANDIA NATL LABS,RADIAT & ELECTROMAGNET ANAL DEPT,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 22 TC 15 Z9 16 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1045-9243 J9 IEEE ANTENNAS PROPAG JI IEEE Antennas Propag. Mag. PD FEB PY 1997 VL 39 IS 1 BP 20 EP 33 DI 10.1109/74.583516 PG 14 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA WQ666 UT WOS:A1997WQ66600004 ER PT J AU Feddema, JT Dohrmann, CR Parker, GG Robinett, RD Romero, VJ Schmitt, DJ AF Feddema, JT Dohrmann, CR Parker, GG Robinett, RD Romero, VJ Schmitt, DJ TI Control for slosh-free motion of an open container SO IEEE CONTROL SYSTEMS MAGAZINE LA English DT Article; Proceedings Paper CT IEEE International Conference on Robotics and Automation CY APR 22-28, 1996 CL MINNEAPOLIS, MN SP IEEE, Robot & Automat Soc ID FREE-SURFACE; WATER RP SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 23 TC 75 Z9 77 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 1066-033X EI 1941-000X J9 IEEE CONTR SYST MAG JI IEEE Control Syst. Mag. PD FEB PY 1997 VL 17 IS 1 BP 29 EP 36 DI 10.1109/37.569711 PG 8 WC Automation & Control Systems SC Automation & Control Systems GA WF350 UT WOS:A1997WF35000006 ER PT J AU Payne, SA Beach, RJ Bibeau, C Ebbers, CA Emanuel, MA Honea, EC Marshall, CD Page, RH Schaffers, KI Skidmore, JA Sutton, SB Krupke, WF AF Payne, SA Beach, RJ Bibeau, C Ebbers, CA Emanuel, MA Honea, EC Marshall, CD Page, RH Schaffers, KI Skidmore, JA Sutton, SB Krupke, WF TI Diode arrays, crystals, and thermal management for solid-state lasers SO IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS LA English DT Article DE solid-state lasers ID AVERAGE-POWER; EMISSION PROPERTIES; ULTRAVIOLET-LASER; MU-M; YAG; NM; PERFORMANCE; CONVERSION; OSCILLATOR; AMPLIFIER AB We summarize our efforts in the development of solid-state lasers, including the laser diode arrays, pump light delivery, approaches to thermal management, and novel gain media, Our interests are in developing unique solid-state lasers, including those operating at higher powers, offering less common wavelengths, and having other specialized features, In this paper, we discuss high-power Tm:YAG and Yb:YAG lasers, the gas-cooled slab laser concept using Yb:B-FAP, and side-pumped Er:YAG and Cr:ZnSe lasers. We address the optical and thermal physics of these systems and also mention several additional gain media that have the potential of offering unique performance characteristics: Ce:LiSAF, APG-2 laser glass, Dy:LaCl3, and Yb:BCBF. RP Payne, SA (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 45 TC 29 Z9 33 U1 5 U2 19 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1077-260X J9 IEEE J SEL TOP QUANT JI IEEE J. Sel. Top. Quantum Electron. PD FEB PY 1997 VL 3 IS 1 BP 71 EP 81 DI 10.1109/2944.585817 PG 11 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA XE895 UT WOS:A1997XE89500013 ER PT J AU Simpson, ML Britton, CL Wintenberg, AL Young, GR AF Simpson, ML Britton, CL Wintenberg, AL Young, GR TI An integrated CMOS time interval measurement system with subnanosecond resolution for the WA-98 calorimeter SO IEEE JOURNAL OF SOLID-STATE CIRCUITS LA English DT Article DE instrumentation; nuclear electronics; time measurements AB The time interval measurement system of the WA-98 calorimeter is presented, This system consists of a constant fraction discriminator (CFD), a variable delay circuit, a time-to-amplitude converter (TAC), and a Wilkinson analog-to-digital converter (ADC) all realized in a 1.2-mu m. V-well CMOS process, These circuits measured the time interval between a reference logic signal and a photomultiplier tube (PMT) signal that had amplitude variations of 100:1 and 10-ns rise and fall times, The system operated over the interval range from 2 us to 200 ns with a resolution of similar to +/-300 ps including all walk and jitter components, The variable delay circuit allowed the CFD output to be delayed by up to 1 mu s with a jitter component of similar to 0.04% of the delay setting, These circuits operated with a 5-V power supply. Although this application was in nuclear physics instrumentation, these circuits could also be useful in other scientific measurements, medical imaging, automatic test equipment, ranging systems, and industrial electronics. RP Simpson, ML (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 12 TC 4 Z9 6 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9200 J9 IEEE J SOLID-ST CIRC JI IEEE J. Solid-State Circuit PD FEB PY 1997 VL 32 IS 2 BP 198 EP 205 DI 10.1109/4.551911 PG 8 WC Engineering, Electrical & Electronic SC Engineering GA WE539 UT WOS:A1997WE53900007 ER PT J AU Gemmell, PS AF Gemmell, PS TI Traceable e-cash SO IEEE SPECTRUM LA English DT Article RP Gemmell, PS (reprint author), SANDIA NATL LABS,TECH STAFF,ALBUQUERQUE,NM 87185, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9235 J9 IEEE SPECTRUM JI IEEE Spectr. PD FEB PY 1997 VL 34 IS 2 BP 35 EP & DI 10.1109/6.570827 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA WF973 UT WOS:A1997WF97300016 ER PT J AU Liberman, V Malba, V Bernhardt, AF AF Liberman, V Malba, V Bernhardt, AF TI Integration of vapor deposited polyimide into a multichip module packaging process SO IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART B-ADVANCED PACKAGING LA English DT Article DE infrared spectroscopy; multichip module; polyimide; refractive index; vapor deposition ID FILMS AB We report the first full integration of a vapor-deposited polyimide dielectric into a multichip module (MCM) electronic packaging scheme, A robust high-throughput vapor deposition polymerization (VDP) of polyimide has been developed for an interconnection scheme in which thin film metal interconnects are patterned from the top of bare die, down the sides, and onto the substrate circuit board surface, VDP polyimides films have been extensively characterized using infrared spectroscopy and prism coupling techniques, The chemical and electrical properties of the VDP polyimide films are similar tea commercially available spin cast polyimides. RP Liberman, V (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 7 TC 6 Z9 6 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 1070-9894 J9 IEEE T COMPON PACK B JI IEEE Trans. Compon. Packag. Manuf. Technol. Part B-Adv. Packag. PD FEB PY 1997 VL 20 IS 1 BP 13 EP 16 DI 10.1109/96.554454 PG 4 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Materials Science, Multidisciplinary SC Engineering; Materials Science GA WH034 UT WOS:A1997WH03400003 ER PT J AU Lai, JS AF Lai, JS TI Resonant snubber-based soft-switching inverters for electric propulsion drives SO IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS LA English DT Article DE electric propulsion; inverter; motor drive; resonant snubber; soft switching AB This paper summarizes recently developed soft-switching inverters and proposes two possible options for electric propulsion drives, The newly developed soft-switching inverter employs an auxiliary switch and a resonant inductor per phase to produce a zero voltage across the main switch, so that the main switch can turn on at the zero-voltage condition, Both the auxiliary switch and the resonant inductor are operating at a fractional duty and, thus, are small in size as compared to the main inverter circuit components, Operation modes in a complete zero-voltage switching cycle for the single-phase soft-switching inverter are described in detail, with graphical explanations. The circuit operation was first verified by a computer simulation, and then further tested with a l-kW single-phase and a 100-kW three-phase inverter, Both simulation and experimental results are presented to show the superior performance in efficiency improvement, EMI reduction, and dv/dt reduction of the proposed soft-switching inverters. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. OI Lai, Jihsheng/0000-0003-2315-8460 NR 18 TC 50 Z9 54 U1 0 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0278-0046 J9 IEEE T IND ELECTRON JI IEEE Trans. Ind. Electron. PD FEB PY 1997 VL 44 IS 1 BP 71 EP 80 DI 10.1109/41.557501 PG 10 WC Automation & Control Systems; Engineering, Electrical & Electronic; Instruments & Instrumentation SC Automation & Control Systems; Engineering; Instruments & Instrumentation GA WL478 UT WOS:A1997WL47800010 ER PT J AU Yuasa, T Akiba, M Takeda, T Kazama, M Hoshino, A Watanabe, Y Hyodo, K Dilmanian, FA Akatsuka, T Itai, Y AF Yuasa, T Akiba, M Takeda, T Kazama, M Hoshino, A Watanabe, Y Hyodo, K Dilmanian, FA Akatsuka, T Itai, Y TI Reconstruction method for fluorescent X-ray computed tomography by least-squares method using singular value decomposition SO IEEE TRANSACTIONS ON NUCLEAR SCIENCE LA English DT Article DE computed tomography; fluorescent X-ray; least-squares method; Monte Carlo simulation; singular value decomposition; synchrotron radiation ID SYNCHROTRON-RADIATION AB We describe a new attenuation correction method for fluorescent X-ray computed tomography (FXCT) applied to image nonradioactive contrast materials in vivo. The principle of the FXCT imaging is that of computed tomography of the first generation, Using monochromatized synchrotron radiation from the BLNE-5A bending-magnet beam line of Tristan Accumulation Ring in KEK, Japan, we studied phantoms with the FXCT method, and we succeeded in delineating a 4-mm-diameter channel filled with a 500 mu g I/ml iodine solution in a 20-mm-diameter acrylic cylindrical phantom, However, to detect smaller iodine concentrations, attenuation correction is needed, We present a correction method based on the equation representing the measurement process, The discretized equation system is solved by the least-squares method using the singular value decomposition, The attenuation correction method is applied to the projections by the Monte Carlo simulation and the experiment to confirm its effectiveness. C1 UNIV TSUKUBA,INST CLIN MED,TSUKUBA,IBARAKI 305,JAPAN. NATL LAB HIGH ENERGY PHYS,PHOTON FACTORY,TSUKUBA,IBARAKI 305,JAPAN. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP Yuasa, T (reprint author), YAMAGATA UNIV,FAC ENGN,YONEZAWA,YAMAGATA 992,JAPAN. RI Yuasa, Tetsuya/F-5006-2013 NR 16 TC 77 Z9 81 U1 0 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9499 J9 IEEE T NUCL SCI JI IEEE Trans. Nucl. Sci. PD FEB PY 1997 VL 44 IS 1 BP 54 EP 62 DI 10.1109/23.554824 PG 9 WC Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA WJ317 UT WOS:A1997WJ31700010 ER PT J AU Hochberg, J Kelly, P Thomas, T Kerns, L AF Hochberg, J Kelly, P Thomas, T Kerns, L TI Automatic script identification from document images using cluster-based templates SO IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE LA English DT Article; Proceedings Paper CT 3rd International Conference on Document Analysis and Recognition CY AUG, 1995 CL MONTREAL, CANADA DE script identification; document analysis; optical character recognition AB We describe an automated script identification system for typeset document images. Templates for each script are created by clustering textual symbols from a training set. Symbols from new images are compared to the templates to find the best script. Our current system processes thirteen scripts with minimal preprocessing and high accuracy. RP Hochberg, J (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87544, USA. NR 9 TC 78 Z9 83 U1 0 U2 4 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 SN 0162-8828 J9 IEEE T PATTERN ANAL JI IEEE Trans. Pattern Anal. Mach. Intell. PD FEB PY 1997 VL 19 IS 2 BP 176 EP 181 DI 10.1109/34.574802 PG 6 WC Computer Science, Artificial Intelligence; Engineering, Electrical & Electronic SC Computer Science; Engineering GA WK728 UT WOS:A1997WK72800013 ER PT J AU Sethian, JA Adalsteinsson, D AF Sethian, JA Adalsteinsson, D TI An overview of level set methods for etching, deposition, and lithography development SO IEEE TRANSACTIONS ON SEMICONDUCTOR MANUFACTURING LA English DT Article ID FREE MOLECULAR-TRANSPORT; CURVATURE FLOW; VISCOSITY SOLUTIONS; PROPAGATING INTERFACES; RECTANGULAR TRENCHES; MEAN-CURVATURE; UNIFIED MODEL; SIMULATIONS; ALGORITHMS; FRONTS AB The range of surface evolution problems in etching, deposition, and lithography development offers significant challenge for numerical methods in front tracking. Level set methods for evolving interfaces are specifically designed for profiles which can develop sharp corners, change topology, and undergo orders of magnitude changes in speed, They are based on solving a Hamilton-Jacobi type equation for a level set function, using techniques borrowed from hyperbolic conservation laws. Over the past few years, a body of level set methods have been developed with application to microfabrication problems, In this paper, we give an overview of these techniques, describe the implementation in etching, deposition, and lithography simulations, and present a collection of fast level set methods, each aimed at a particular application, In the case of photoresist development and isotropic etching/deposition, the fast marching level set method, introduced by Sethian in [39], [40], can track the three-dimensional photoresist process through a 200x200x 200 rate function grid in under 55 s on a Sparc10. In the case of more complex etching and deposition, the narrow band level set method, introduced in Adalsteinsson and Sethian in [2], can be used to handle problems in which the speed of the interface delicately depends on the orientation of the interface versus an incoming beam, the effects of visibility, surface tension, reflection and re-emission, and complex three-dimensional effects, Our applications include photoresist development, etching/deposition problems under the effects of masking, visibility, complex flux integrations over sources, nonconvex sputter deposition problems, and simultaneous deposition and etch phenomena. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. RP Sethian, JA (reprint author), UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720, USA. NR 47 TC 81 Z9 84 U1 1 U2 15 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0894-6507 J9 IEEE T SEMICONDUCT M JI IEEE Trans. Semicond. Manuf. PD FEB PY 1997 VL 10 IS 1 BP 167 EP 184 DI 10.1109/66.554505 PG 18 WC Engineering, Manufacturing; Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA WG842 UT WOS:A1997WG84200017 ER PT J AU KunzSchughart, LA Freyer, JP AF KunzSchughart, LA Freyer, JP TI Adaptation of an automated selective dissociation procedure to two novel spheroid types SO IN VITRO CELLULAR & DEVELOPMENTAL BIOLOGY-ANIMAL LA English DT Letter ID HUMAN-TUMOR XENOGRAFTS; MULTICELLULAR SPHEROIDS; CELL SUBPOPULATIONS; CENTRIFUGAL ELUTRIATION; DIFFERENT REGIONS; GROWTH C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NCI NIH HHS [CA-51150] NR 17 TC 8 Z9 8 U1 0 U2 2 PU SOC IN VITRO BIOLOGY PI LARGO PA 9315 LARGO DR WEST, STE 25, LARGO, MD 20774 SN 1071-2690 J9 IN VITRO CELL DEV-AN JI In Vitro Cell. Dev. Biol.-Anim. PD FEB PY 1997 VL 33 IS 2 BP 73 EP 76 PG 4 WC Cell Biology; Developmental Biology SC Cell Biology; Developmental Biology GA WP529 UT WOS:A1997WP52900001 PM 9081211 ER PT J AU Zhong, GM Sajonz, P Guiochon, G AF Zhong, GM Sajonz, P Guiochon, G TI Shock layer theory and concentration dependence of the axial dispersion and the mass-transfer rate coefficients SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID LIGHT-SCATTERING; EXCHANGE SYSTEMS; FRONTAL ANALYSIS; CHROMATOGRAPHY; ADSORPTION; DIFFUSION; THICKNESS AB Independent determinations of the coefficients of axial dispersion and of the mass-transfer kinetics have been found to be concentration dependent in protein chromatography. The consequences of this observation are studied on a theoretical basis. Numerical calculations of breakthrough curves were carried out, assuming a linear dependence of these coefficients on the solute concentration. The results obtained illustrate the influence of the concentration dependence on chromatographic band profiles. The classical shock layer theory, which assumes constant coefficients, was extended to the case in which they depend linearly on the concentration. The analytical solution of the shock layer profile agrees with all the results of the numerical calculations. Consideration of the shock layer thickness provides an easy access to the kinetic information contained in the breakthrough profiles. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV ANALYT CHEM,OAK RIDGE,TN 37831. NR 17 TC 19 Z9 19 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0888-5885 J9 IND ENG CHEM RES JI Ind. Eng. Chem. Res. PD FEB PY 1997 VL 36 IS 2 BP 506 EP 509 DI 10.1021/ie960457a PG 4 WC Engineering, Chemical SC Engineering GA WG064 UT WOS:A1997WG06400031 ER PT J AU Antonio, MR Dietz, ML Jensen, MP Soderholm, L Horwitz, EP AF Antonio, MR Dietz, ML Jensen, MP Soderholm, L Horwitz, EP TI EXAFS studies of cesium complexation by dibenzo-crown ethers in tri-n-butyl phosphate SO INORGANICA CHIMICA ACTA LA English DT Article DE EXAFS; cesium complexes; crown ether complexes; complexation; extraction ID X-RAY-ABSORPTION; FINE-STRUCTURE; 15-CROWN-5 COMPLEXES; AQUEOUS-SOLUTIONS; L-EDGES; SPECTROSCOPY; EXTRACTION; SOLIDS; PRASEODYMIUM; 12-CROWN-4 AB Cesium K- and L(3)-edge EXAFS (Extended X-ray Absorption Fine Structure) have been evaluated as means of probing the interaction of cesium ions with several dibenzo-crown ethers in tri-n-butyl phosphate (TBP) under conditions proposed for the extraction of radiocesium from acidic nuclear wastes. K-edge EXAFS data are shown to be less satisfactory than the corresponding L(3)-edge data, a result of the difficulties inherent in the use of high X-ray energies, the weak spectral contributions of carbon and oxygen at long distances, the disorder characteristic of solution systems, and the low cesium concentrations present. Despite these difficulties, the EXAFS data yield information on the solution structure of the cesium-crown ether complexes that complements results obtained from liquid-liquid extraction studies. Specifically, the coordination of cesium in TBP is shown to differ from that observed in the same solvent upon addition of a dibenzo-crown ether. In addition, cesium coordination by the crown ethers is shown to be unaffected by the presence of water or the identity of the counterion. Finally, the average Cs-O bond length is shown to decrease from 3.23(3) Angstrom in the cesium di-(tert-butylbenzo)-18-crown-6 complex to 3.01(4) Angstrom in the corresponding 21-crown-7 and 24-crown-8 compounds, a result consistent with extraction studies indicating 1:1 complex formation in the 21-crown-7 and 24-crown-8 systems and a mixture of 1:1 and 1:2 complexes for the 18-crown-6. RP Antonio, MR (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Jensen, Mark/G-9131-2012; OI Jensen, Mark/0000-0003-4494-6693; Antonio, Mark/0000-0002-1208-4534 NR 56 TC 19 Z9 19 U1 2 U2 13 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 FEB 1 PY 1997 VL 255 IS 1 BP 13 EP 20 DI 10.1016/S0020-1693(96)05198-5 PG 8 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WK731 UT WOS:A1997WK73100003 ER PT J AU Morss, LR Rogers, RD AF Morss, LR Rogers, RD TI Syntheses and crystal structures of [M(NO3)(2)(tpen)][NO3]center dot 3H(2)O (M=La, Tb), rare earth complexes with strong M-N bonds SO INORGANICA CHIMICA ACTA LA English DT Article DE crystal structures; lanthanum complexes; polydentate amino ligand complexes; chelate complexes ID X-RAY; LIGANDS; LANTHANUM(III); HEXADENTATE; EUROPIUM(III); COBALT(III); CORE AB The compounds [M(NO3)(2)(tpen)][NO3]. 3H(2)O with M = La, Nd, Eu, To and Y have been synthesized. Single crystals have been grown of the compounds with M=La and Tb from water-ethanol solution. Their crystal structures have been determined, The compounds are isostructural; the metals are ten-fold coordinated, with six nitrogens from one tpen ligand and four oxygens from two nitrates. Growth of crystals with nitrogen coordinated to rare earths in water-containing solution is unusual and indicates that tpen is a good nitrogen donor even with hard cations. C1 NO ILLINOIS UNIV,DEPT CHEM,DE KALB,IL 60115. RP Morss, LR (reprint author), ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439, USA. RI Rogers, Robin/C-8265-2013 OI Rogers, Robin/0000-0001-9843-7494 NR 25 TC 33 Z9 33 U1 1 U2 4 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 FEB 1 PY 1997 VL 255 IS 1 BP 193 EP 197 DI 10.1016/S0020-1693(96)05353-4 PG 5 WC Chemistry, Inorganic & Nuclear SC Chemistry GA WK731 UT WOS:A1997WK73100030 ER PT J AU North, SW Fei, RA Sears, TJ Hall, GE AF North, SW Fei, RA Sears, TJ Hall, GE TI CN radical reaction rate measurements by time-resolved FM spectroscopy SO INTERNATIONAL JOURNAL OF CHEMICAL KINETICS LA English DT Article ID FREQUENCY-MODULATION SPECTROSCOPY AB Time-resolved frequency-modulation spectroscopy is shown to be an effective method for measuring the rates of gas-phase reactions. As an example, the rate constant for the reaction of CN with C2H4 at 298 K is measured to be 2.5 +/- 0.2 X 10(-10) cm(3)s(-1), in good agreement with other literature values. The efficiency and sensitivity of this technique will be of interest to the chemical kineticist. (C) 1997 John Wiley & Sons, Inc. RP North, SW (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. 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 15 TC 19 Z9 19 U1 0 U2 2 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0538-8066 J9 INT J CHEM KINET JI Int. J. Chem. Kinet. PD FEB PY 1997 VL 29 IS 2 BP 127 EP 129 DI 10.1002/(SICI)1097-4601(1997)29:2<127::AID-KIN6>3.0.CO;2-W PG 3 WC Chemistry, Physical SC Chemistry GA WD893 UT WOS:A1997WD89300006 ER PT J AU Mitchell, SA AF Mitchell, SA TI Finding a covering triangulation whose maximum angle is provably small SO INTERNATIONAL JOURNAL OF COMPUTATIONAL GEOMETRY & APPLICATIONS LA English DT Article; Proceedings Paper CT MSI Stony Brook Workshop on Computational Geometry CY OCT 14-16, 1993 CL RALEIGH, NC DE triangulation; maximum angle; boundary points AB We consider the following problem: given a planar straight-line graph, find a covering triangulation whose maximum angle is as small as possible. A coveting triangulation is a triangulation whose vertex set contains the input vertex set and whose edge set contains the input edge set. The covering triangulation problem differs from the usual Steiner triangulation problem in that we may not add a vertex on any input edge. Covering triangulations provide a convenient method for triangulating multiple regions sharing a common boundary, as each region can be triangulated independently. We give an explicit lower bound gamma(opt) On the maximum angle in any covering triangulation of a particular input graph in terms of its local geometry. Our algorithm produces a covering triangulation whose maximum angle gamma is provably dose to gamma(opt). Specifically, we show that pi-gamma greater than or equal to min(pi-gamma(opt)/2, pi/6), i.e., our gamma is not much closer to pi than is gamma(opt). To our knowledge, this result represents the first nontrivial bound on a covering triangulation's maximum angle. Our algorithm adds O(n) Steiner points and rum in time O(n log n), where n is the number of vertices of the input. We have implemented an O(n(2)) time version of our algorithm. C1 SANDIA NATL LABS,COMPUTAT MECH & VISUALIZAT DEPT,ALBUQUERQUE,NM 87185. NR 14 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-1959 J9 INT J COMPUT GEOM AP JI Int. J. Comput. Geom. Appl. PD FEB-APR PY 1997 VL 7 IS 1-2 BP 5 EP 20 DI 10.1142/S021819599700003X PG 16 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA WT551 UT WOS:A1997WT55100002 ER PT J AU Winters, WS Evans, GH Greif, R AF Winters, WS Evans, GH Greif, R TI Mixed binary convection in a rotating disk chemical vapor deposition reactor SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article ID HEAT-TRANSFER; FLOW C1 UNIV CALIF BERKELEY,DEPT MECH ENGN,BERKELEY,CA 94720. RP Winters, WS (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 7 TC 6 Z9 6 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0017-9310 J9 INT J HEAT MASS TRAN JI Int. J. Heat Mass Transf. PD FEB PY 1997 VL 40 IS 3 BP 737 EP & DI 10.1016/0017-9310(96)00092-0 PG 7 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA VQ587 UT WOS:A1997VQ58700020 ER PT J AU Jones, SE Maudlin, PJ Foster, JC AF Jones, SE Maudlin, PJ Foster, JC TI An engineering analysis of plastic wave propagation in the Taylor test SO INTERNATIONAL JOURNAL OF IMPACT ENGINEERING LA English DT Article ID MODEL AB A new one-dimensional analysis of the Taylor impact test is presented. This analysis differs from any previously presented in that the wave mechanics are separated from the calculation of dynamic stress. The new results utilize post test measurements to estimate key parameters in the plastic wave propagation. However, these measurements are incorporated into the analysis in a very unconventional way. A comparison with continuum code calculations shows very good agreement has been achieved. Copyright (C) 1996 Elsevier Science Ltd. C1 LOS ALAMOS NATL LAB,DIV THEORET,GRP T3,LOS ALAMOS,NM 87545. USAF,WRIGHT LAB,ARMAMENT DIRECTORATE,EGLIN AFB,FL 32542. RP Jones, SE (reprint author), UNIV ALABAMA,DEPT AEROSP ENGN & MECH,TUSCALOOSA,AL 35487, USA. NR 17 TC 13 Z9 18 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0734-743X J9 INT J IMPACT ENG JI Int. J. Impact Eng. PD FEB PY 1997 VL 19 IS 2 BP 95 EP 106 DI 10.1016/S0734-743X(96)00020-6 PG 12 WC Engineering, Mechanical; Mechanics SC Engineering; Mechanics GA WC433 UT WOS:A1997WC43300002 ER PT J AU Grannan, SM Richards, PL Hase, MK AF Grannan, SM Richards, PL Hase, MK TI Numerical optimization of bolometric infrared detectors including optical loading, amplifier noise, and electrical nonlinearities SO INTERNATIONAL JOURNAL OF INFRARED AND MILLIMETER WAVES LA English DT Article DE bolometers; optimization; infrared ID HOPPING CONDUCTION; TRANSPORT; GERMANIUM; ELECTRONS AB We present numerical methods for the optimization of bolometric infrared detectors which use current-biased semiconducting thermistors. We extend the analysis of Griffin and Holland to explicitly include both the electric field dependence of the thermistor resistance and amplifier noise. These methods allow the user to design and evaluate an optimized bolometer once such parameters as the optical loading, the heat sink temperature, and the materials for the thermal link and the thermistor have been chosen. Measured parameters which describe the electrical nonlinearities in neutron transmutation doped germanium are presented. The consequences for bolometer optimization of including these effects are illustrated. This program will be made available at the web site http://physics7.berkeley.edulbolometer.html. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT ELECT ENGN & COMP SCI,BERKELEY,CA 94720. RP Grannan, SM (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 24 TC 10 Z9 10 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-9271 J9 INT J INFRARED MILLI JI Int. J. Infrared Millimeter Waves PD FEB PY 1997 VL 18 IS 2 BP 319 EP 340 DI 10.1007/BF02677923 PG 22 WC Engineering, Electrical & Electronic; Optics; Physics, Applied SC Engineering; Optics; Physics GA WM704 UT WOS:A1997WM70400004 ER PT J AU Duan, YX Chamberlin, EP Olivares, JA AF Duan, YX Chamberlin, EP Olivares, JA TI Development of a new high-efficiency thermal ionization source for mass spectrometry SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE thermal ionization; ion source; high efficiency; quadrupole; mass spectrometry; isotope separation; isotope ratios; instrumentation ID ION-SOURCE; SURFACE-IONIZATION; HOT CAVITY; URANIUM AB A thermal ionization source for mass spectrometry has been designed and tested. The ion source is based on a tungsten crucible with a deep cavity into which the sample is loaded. The crucible is heated by high energy electron bombardment from a tantalum filament surrounding the crucible. As the sample evaporates inside the crucible, gaseous analyte atoms are produced which interact with the inner surface of the crucible walls to produce positive ions through surface ionization. The ions are extracted from the cavity through a small opening at the end of the crucible. Regulation of the electron emission current makes it possible to control the energy and power applied to the crucible and, therefore, the crucible temperature. A number of elements have been tested in this source. The ionization efficiencies measured using a high transmission isotope separator spectrometer show 10 to 100 times higher efficiency than in conventional surface thermal ionization sources. (C) 1997 Elsevier Science B.V. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 36 TC 17 Z9 17 U1 1 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-1176 J9 INT J MASS SPECTROM JI Int. J. Mass Spectrom. Ion Process. PD FEB PY 1997 VL 161 IS 1-3 BP 27 EP 39 DI 10.1016/S0168-1176(96)04434-5 PG 13 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA WU565 UT WOS:A1997WU56500005 ER PT J AU Morris, GM Coderre, JA Hopewell, JW Rezvani, M Micca, PL Fisher, CD AF Morris, GM Coderre, JA Hopewell, JW Rezvani, M Micca, PL Fisher, CD TI Response of the central nervous system to fractionated boron neutron capture irradiation: Studies with borocaptate sodium SO INTERNATIONAL JOURNAL OF RADIATION BIOLOGY LA English DT Article ID RAT SPINAL-CORD; X-RAYS; RADIATION-DAMAGE; THERAPY; SINGLE; CELLS; MODEL AB The response of the central nervous system (CNS) to fractionated doses of boron neutron capture (BNC) irradiation was assessed using a rat spinal cord model. The thermal neutron beam at the Brookhaven Medical Research Reactor (BMRR) was used for the spinal cord irradiations, with borocaptate sodium (BSH) as the neutron capture agent. Irradiations were given as a single dose or as two or four equal fractions. The ED(50) for radiation-induced myeloparesis, as indicated by limb paralysis within 7 months, after a single exposure to thermal neutrons in the presence of BSH (blood boron-10 content similar to 70 mu g/g) was 27.2 +/- 0.9 Gy. This was expressed as the total physical dose to the blood. Dividing the radiation dose into two consecutive daily fractions or four fractions given over 1 week, resulted in ED(50)=32.0 +/- 1.4 and 31.5 +/- 0.4 Gy respectively. Although there was no significant dose sparing in moving from two to four fractions, there was a dose increment of similar to 17% as compared with single-dose irradiation. The variation in the relative biological effectiveness of the thermal neutron beam, with dose per fraction, was established using data from a previous study with single and fractionated doses of thermal neutrons in the absence of a neutron capture agent. This varied from 1.40 to 3.74 for thermal neutron dose per fraction in the range 13.6-1.5 Gy. Previously published CBE factors for both BSH and BPA have been recalculated in the present report to take into account the change in the RBE of the thermal neutron beam with dose. In all cases the recalculated CBE factors were lower than those obtained previously. Values for this parameter increased with fraction number. In the case of BSH, the CBE factor increased from 0.36 +/- 0.03 after a single-dose to 0.51 +/- 0.06 after four fractions. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP Morris, GM (reprint author), UNIV OXFORD,CHURCHILL HOSP,RES INST,OXFORD OX3 7LJ,ENGLAND. NR 30 TC 14 Z9 14 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0955-3002 J9 INT J RADIAT BIOL JI Int. J. Radiat. Biol. PD FEB PY 1997 VL 71 IS 2 BP 185 EP 192 PG 8 WC Biology; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging SC Life Sciences & Biomedicine - Other Topics; Nuclear Science & Technology; Radiology, Nuclear Medicine & Medical Imaging GA WP582 UT WOS:A1997WP58200007 PM 9120354 ER PT J AU Yang, WL Barth, RF Rotaru, JH Moeschberger, ML Joel, DD Nawrocky, MM Goodman, JH Soloway, AH AF Yang, WL Barth, RF Rotaru, JH Moeschberger, ML Joel, DD Nawrocky, MM Goodman, JH Soloway, AH TI Boron neutron capture therapy of brain tumors: Enhanced survival following intracarotid injection of sodium borocaptate with or without blood-brain barrier disruption SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article; Proceedings Paper CT 7th International Symposium on Neutron Capture Therapy CY SEP 04-07, 1996 CL ZURICH, SWITZERLAND DE boron neutron capture therapy; blood-brain barrier disruption; sodium borocaptate; intracarotid injection; rat glioma ID DRUG-DELIVERY; RAT GLIOMA; INTRACRANIAL TUMORS; BIODISTRIBUTION; BORONOPHENYLALANINE; GLIOBLASTOMA; NA2B12H11SH; SULFHYDRYL; EFFICACY; MODEL AB Purpose: Sodium borocaptate (Na2B12H11SH or BSH) has been used clinically for boron neutron capture therapy (BNCT) of patients with primary brain tumors. The purpose of the present study was to determine if tumor uptake of BSH and efficacy of BNCT could be enhanced in F98 glioma-bearing rats by intracarotid (i.c.) injection of the compound with or without blood-brain barrier disruption (BBB-D). Methods and Materials: For biodistribution studies 100,000 F98 glioma cells were implanted stereotactically into the brains of Fischer rats, and 12 days later BBB-D was carried out by i.c. infusion of 25% mannitol, followed immediately thereafter by i.c. injection of BSH (30 mg B/kg body weight). Animals were killed 1, 2.5, and 5 h later, and their brains were removed for boron determination. For BNCT experiments, which were initiated 14 days after intracerebral implantation of 1000 F98 cells, BSH (30 mg B/kg b.wt. was administered intravenously (i.v.) without BBB-D, or i.c. with or without BBB-D. The animals were irradiated 2.5 h later with a collimated beam of thermal neutrons at the Brookhaven National Laboratory Medical Research Reactor. Results: The mean tumor boron concentration after i.c. injection with BBB-D was 48.6 +/- 17.2 mu g/g at 2.5 h compared with 30.8 +/- 12.2 mu g/g after i.c. injection without BBB-D and 12.9 +/- 4.2 mu g/g after i.v. injection. The best composite tumor to normal tissue ratios were observed at 2.5 h after BBB-D, at which time the tumor:blood (T:B1) ratio was 5.0, and the tumor: brain (T:Br) ratio was 12.3, compared to 1.1 and 4.6, respectively, in i.v. injected rats. The mean survival time for untreated control rats was 24 +/- 3 days, 29 +/- 4 days for irradiated controls, 33 +/- 6 days for those receiving i.v. injection of BSH, 40 +/- 8 days for rats receiving i.c. BSH without BBB-D, and 52 +/- 13 days for BBB-B followed by BNCT (p = 0.003 vs. i.v. injected BSH). Conclusions: Intracarotid administration of BSH with or without BBB-D significantly increased tumor uptake of BSH and enhanced survival of F98 glioma-bearing rats following BNCT. BBB-D may be a useful way to enhance the delivery of both low and high molecular weight boron compounds to brain tumors. Further studies are in progress to assess this approach with other boron delivery agents. (C) 1997 Elsevier Science Inc. C1 OHIO STATE UNIV,SCH PUBL HLTH,DEPT PATHOL,COLUMBUS,OH 43210. OHIO STATE UNIV,SCH PUBL HLTH,DIV EPIDEMIOL & BIOMETR,COLUMBUS,OH 43210. OHIO STATE UNIV,DIV NEUROSURG,COLUMBUS,OH 43210. OHIO STATE UNIV,COLL PHARM,COLUMBUS,OH 43210. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. NR 56 TC 42 Z9 42 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0360-3016 J9 INT J RADIAT ONCOL JI Int. J. Radiat. Oncol. Biol. Phys. PD FEB 1 PY 1997 VL 37 IS 3 BP 663 EP 672 DI 10.1016/S0360-3016(96)00082-X PG 10 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA WU360 UT WOS:A1997WU36000023 PM 9112465 ER PT J AU Munson, DE AF Munson, DE TI Constitutive model of creep in rock salt applied to underground room closure SO INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES LA English DT Article ID DEFORMATION-MECHANISM MAPS AB A multimechanism constitutive model of the creep of polycrystalline rock salt has been developed based on steady state creep as modified to incorporate transient creep through workhardening and recovery. Application of the model is in calculation of the closure of underground rooms excavated in a natural, bedded evaporite salt deposit. This requires an integrated technology consisting of not only the proper constitutive model, but also a range of other system elements relating to the site geology, initial and boundary conditions, and numerical methods peculiar to the application. Through finite element calculations, this model, with appropriate laboratory material parameters and a Tresca flow potential, has predicted the closure of a number of large, in situ experimental rooms at the Waste Isolation Pilot Plant (WIPP). In this paper, an overview of the model development, laboratory parameter generation and numerical simulation capability is given, together with a summary of the comparisons of the calculated and measured creep closure results. The comparisons encompass a range of test room configurations that exercise the predictive capability for stratigraphic setting, room geometry, thermal heating, stress field interaction and two and three-dimensional deformation fields. The simulations have proven satisfactory and suggest the general adequacy of the predictive technology. (C) 1997 Published by Elsevier Science Ltd. RP Munson, DE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 35 TC 45 Z9 50 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0148-9062 J9 INT J ROCK MECH MIN JI Int. J. Rock Mech. Min. Sci. PD FEB PY 1997 VL 34 IS 2 BP 233 EP 247 DI 10.1016/S0148-9062(96)00047-2 PG 15 WC Engineering, Geological; Mining & Mineral Processing SC Engineering; Mining & Mineral Processing GA WQ978 UT WOS:A1997WQ97800007 ER PT J AU Christensen, RM AF Christensen, RM TI Stress based yield/failure criteria for fiber composites SO INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES LA English DT Article ID HYDROSTATIC-PRESSURE; FAILURE CRITERIA AB A macroscopic yield or failure criterion is derived for fiber composite materials. The derivation decomposes naturally into two modes of yield/failure, one being matrix dominated, the other being fiber dominated, thus there are two governing criteria. The resulting forms are quadratic in the components of the average stress tensor with two material parameters for each mode of yield;failure. The physical context of the formulation is that of aligned fiber systems with a polymeric matrix phase under high fiber concentration conditions. Copyright (C) 1996 Elsevier Science Ltd. C1 STANFORD UNIV,STANFORD,CA 94305. RP Christensen, RM (reprint author), LAWRENCE LIVERMORE NATL LAB,LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA, USA. NR 12 TC 50 Z9 51 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0020-7683 J9 INT J SOLIDS STRUCT JI Int. J. Solids Struct. PD FEB PY 1997 VL 34 IS 5 BP 529 EP 543 DI 10.1016/S0020-7683(96)00038-8 PG 15 WC Mechanics SC Mechanics GA WB893 UT WOS:A1997WB89300001 ER PT J AU Sethi, V Patnaik, P Biswas, P Clark, RM Rice, EW AF Sethi, V Patnaik, P Biswas, P Clark, RM Rice, EW TI Evaluation of optical detection methods for waterborne suspensions SO JOURNAL AMERICAN WATER WORKS ASSOCIATION LA English DT Article ID AEROSOL-SIZE DISTRIBUTION; LIGHT-SCATTERING; PARTICLE COUNTERS; TURBIDITY; SPECTRODISSYMMETRY AB Turbidimeters and optical particle counters (OPCs) are used to monitor particulate matter in water. The response from these instruments is governed by the optical properties of the suspension and the instrument design. The recommended design criteria for turbidimeters allow for large tolerances that lead to variations in measurements from different instruments. OPCs provide size-specific information but may inaccurately size microorganisms or particles having optical properties different from those of the calibration particles. The authors evaluate the effects of optical design parameters in turbidimeters and OPCs. Performance data from two OPCs are presented. A multiple-angle Light-scattering method was developed to obtain ''optical signatures'' from suspensions of monodisperse spheres and several micro organism is elates. Such ''signatures'' provide more optical information on waterborne particles and may also be used to identify specific types of microorganisms in real time. C1 UNIV CINCINNATI,DEPT CIVIL & ENVIRONM ENGN,CINCINNATI,OH 45221. US EPA,OAK RIDGE INST SCI & EDUC,WATER SUPPLY & WATER RESOURCES DIV,NATL RISK MANAGEMENT LAB,CINCINNATI,OH 45268. NR 46 TC 13 Z9 13 U1 0 U2 4 PU AMER WATER WORKS ASSOC PI DENVER PA 6666 W QUINCY AVE, DENVER, CO 80235 SN 0003-150X J9 J AM WATER WORKS ASS JI J. Am. Water Work Assoc. PD FEB PY 1997 VL 89 IS 2 BP 98 EP 112 PG 15 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA WJ433 UT WOS:A1997WJ43300016 ER PT J AU Allen, LA Leach, JJ Pang, HM Houk, RS AF Allen, LA Leach, JJ Pang, HM Houk, RS TI Precise measurement of ion ratios in solid samples using laser ablation with a twin quadrupole inductively coupled plasma mass spectrometer SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE laser ablation; inductively coupled plasma mass spectrometry; internal standard; isotope ratio; solids analysis ID ELEMENTAL ANALYSIS; LEAD; GEOCHRONOLOGY; PERFORMANCE; HAFNIUM; ZIRCON AB Laser ablation (LA) is used with steel samples to assess the ability of a twin quadrupole inductively coupled plasma mass spectrometer to eliminate flicker noise, Isotopic and internal standard ratios are measured in the first part of this work, Results indicate that flicker noise cancels and significant improvements in precision are possible, The isotope ratio Cr-52(+):Cr-53(+) can be measured with a relative standard deviation (RSD) of 0.06-0.1%, depending on the dwell time and averaging method used, The level of noise above the shot noise limit is greater in internal standard measurements than when doing isotope ratio measurements, Nevertheless, RSDs improve from 1.9% in the Cr+ signal to 0.12% for the ratio of V-51(+) to Cr-52(+) in a steel standard reference material (SRM). In the second part of this work, one mass spectrometer is scanned while the second channel measures an individual m/z value, When the ratio of these two signals is calculated, the peak shapes in the mass spectrum are improved significantly for a wide range of elements, This technique corrects for Bicker noise from the LA process while scanning a mass spectrum for multi-element determinations. RP Allen, LA (reprint author), IOWA STATE UNIV,DEPT CHEM,US DOE,AMES LAB,AMES,IA 50011, USA. NR 25 TC 20 Z9 20 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD FEB PY 1997 VL 12 IS 2 BP 171 EP 176 DI 10.1039/a603310e PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA WK749 UT WOS:A1997WK74900012 ER PT J AU Mao, XL Russo, RE AF Mao, XL Russo, RE TI Optimization and calibration of laser ablation inductively coupled plasma atomic emission spectrometry by measuring vertical spatial intensity profiles SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE laser ablation sampling; inductively coupled plasma atomic emission spectrometry; vertical spatial profile; optimization; calibration ID MASS-SPECTROMETRY; ELECTROTHERMAL VAPORIZATION; ELEMENTAL ANALYSIS; SPECTROSCOPY; TRANSPORT; SAMPLES; SYSTEM; MATRIX; RATIOS; WATER AB Vertical spatial emission intensity profiles for ICP-AES were measured to optimize and calibrate laser ablation sampling. Laser ablation sampling and laser ablation plus liquid nebulization sampling were studied. The position of maximum ICP emission intensity above the rf load coil changes with gas flow rate for both cases, with the maximum position shifting to higher regions in the plasma at higher flow rates. The maximum emission intensity occurs at a flow rate of approximately 0.2-0.31 min(-1) and at approximately 5-10 mm above the load coil, which are significantly different to the values normally employed for liquid nebulization. In addition, by measuring the spatial emission profiles for laser ablation and nebulization sampling, solutions can be used as standards to calibrate the composition of the laser ablated mass. Calibrated Zn:Cu ratios were measured using UV nanosecond and picosecond laser pulses. Stoichiometric laser ablation sampling of a brass alloy was achieved only by using UV picosecond laser pulses at high power density. RP Mao, XL (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 43 TC 26 Z9 26 U1 0 U2 2 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD FEB PY 1997 VL 12 IS 2 BP 177 EP 182 DI 10.1039/a606059e PG 6 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA WK749 UT WOS:A1997WK74900013 ER PT J AU Mahan, CA AF Mahan, CA TI Evaluation of a direct current arc charge injection device spectrograph for direct analysis of soils SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE direct current arc; solids analysis; trace metal analysis; charge injection device ID ICP-OES; DETECTOR AB The feasibility of using a de are charge injection device (CID) spectrograph for the semiquantitative determination of metals in soils has been demonstrated, Ar-O-2 gas in a proportion of 70 + 30 was delivered through a Stallwood jet at 5 mi min(-1) while 20 mg of sample were burned using 15 A of current and a constant 4 mm electrode gap, SPEX multi-element graphite powders were used to map wavelengths on the CTD sensor and construct working cur, cs. The CRM SO-1 was diluted with graphite powder and analysed. The analysis was accomplished using the full-frame capability of the CID, which permitted the evaluation of several analytical lines for the target elements, Several elements, including Ag, Be, Cd, Hg, Sb and Se, were present in the diluted sample at less than 5 mu g g(-1), and results corroborated these low concentrations. Quantitative results were obtained for P and Pb, semiquantitative results were achieved for Ba, Mn and Sr, and results for B, Co, Cr, Cu, Ni, V and Zn were qualitative. Detection limits were determined by burning three samples of pure graphite powder. Detection limits for Ag, B, Ba, Be, Cd, Co, Hg, Mn and Ni were less than or equal to 2 mu g g(-1); for Cr, P, Pb, Sb, Se, Sr, V and Zn less than or equal to 5 mu g g(-1), and for As, Cu and T1 less than or equal to 10 mu g g(-1). The relative precision of the method was examined bJ' burning three separate 33 mu g g(-1) multi-element SPEX standards, Most elements showed RSDs of less than 20% with the exception of As, Cd, Co, Ni, P and Zn, Ni and Zn showed the greatest imprecision at about 70% and 55% RSD, respectively. The use of Li2CO3 to buffer the are temperature improved the precision for most elements, especially Ni and Zn. RP Mahan, CA (reprint author), LOS ALAMOS NATL LAB, CHEM SCI & TECHNOL DIV, INORGAN TRACE ANAL GRP, CST-9, MS G740, LOS ALAMOS, NM 87545 USA. NR 11 TC 6 Z9 6 U1 0 U2 1 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0267-9477 J9 J ANAL ATOM SPECTROM JI J. Anal. At. Spectrom. PD FEB PY 1997 VL 12 IS 2 BP 247 EP 254 DI 10.1039/a605049b PG 8 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA WK749 UT WOS:A1997WK74900021 ER PT J AU Gibaud, A Harlow, D Hastings, JB Hill, JP Chapman, D AF Gibaud, A Harlow, D Hastings, JB Hill, JP Chapman, D TI A high-energy monochromatic Laue (MonoLaue) X-ray diffuse scattering study of KMnF3 using an image plate SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID R-POINT INSTABILITY; NEUTRON-SCATTERING; SRTIO3 AB The technique of high-energy monochromatic Laue X-ray scattering using image plates to record the diffraction patterns is presented. A tunable wiggler beamline is used as an X-ray source. It is shown that such experimental conditions present many advantages over conventional tube sources and photographic films. A study of diffuse scattering in the perovskite compound KMnF3 is presented to illustrate this in a qualitative way. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. DUPONT CO INC,WILMINGTON,DE 19880. BROOKHAVEN NATL LAB,UPTON,NY 11973. RI Chapman, Dean/I-6168-2013 OI Chapman, Dean/0000-0001-6590-4156 NR 14 TC 13 Z9 13 U1 0 U2 3 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD FEB PY 1997 VL 30 BP 16 EP 20 DI 10.1107/S0021889896000696 PN 1 PG 5 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WJ441 UT WOS:A1997WJ44100002 ER PT J AU Norby, P AF Norby, P TI Synchrotron powder diffraction using imaging plates: Crystal structure determination and Rietveld refinement SO JOURNAL OF APPLIED CRYSTALLOGRAPHY LA English DT Article ID X-RAY; HIGH-PRESSURE; QUARTZ; CRYSTALLOGRAPHY AB The combination of intense X-ray synchrotron radiation and an imaging-plate area detector makes it possible to extract real-time structural information using Rietveld refinement of individual time slices. Powder diffraction data from capillary samples were collected using a flat imaging plate mounted perpendicular to, or at an oblique angle to, the incoming beam. Owing to the geometry of the experiments, several factors must be taken into account when Rietveld refinement of powder diffraction data obtained using a flat imaging plate is performed: (i) nonequal step sizes are obtained when the diffraction profiles are extracted; (ii) the refined zero-point correction is different from that for conventional diffraction geometry; (iii) the sample-detector distance is not constant, requiring a modified geometric term in the Lorentz factor; (iv) the geometric contribution to the instrumental resolution function must be considered. The geometric factors have been derived and are discussed. The Rietveld program XRS-82 and the profile extraction program ALLHKL have been modified to allow flat imaging-plate powder diffraction data to be refined. The Rietveld refinement of powder diffraction data of alpha-quartz collected using a 30 s exposure is presented. LaB6 powder diffraction data were collected using various settings. The profile variation with angle and the resolution function are described. Data were collected up to sin theta/lambda = 1.29 Angstrom(-1) (d values down to 0.39 Angstrom) using high energy and with the imaging plate inclined at an angle to the incoming beam. RP Norby, P (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Norby, Poul/B-9047-2014 OI Norby, Poul/0000-0002-2590-7050 NR 27 TC 111 Z9 111 U1 1 U2 14 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0021-8898 J9 J APPL CRYSTALLOGR JI J. Appl. Crystallogr. PD FEB PY 1997 VL 30 BP 21 EP 30 DI 10.1107/S0021889896009995 PN 1 PG 10 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA WJ441 UT WOS:A1997WJ44100003 ER PT J AU Bossert, JE AF Bossert, JE TI An investigation of flow regimes affecting the Mexico City region SO JOURNAL OF APPLIED METEOROLOGY LA English DT Article ID LOS-ANGELES BASIN; MOUNTAINOUS TERRAIN; SCALE FLOWS; MODEL; METEOROLOGY; TEMPERATURE; ATMOSPHERE; TRANSPORT; POLLUTION AB The Regional Atmospheric Modeling System (RAMS) is used to investigate the detailed mesoscale flow structure over the Mexico City region for a 3-day period in February 1991. The model simulation is compared with rawinsonde and tethersonde profile data and measurements from two surface stations in the southwestern part of Mexico City. The model results show that downward momentum transfer from aloft increases southerly winds near the surface on the first case day, effectively sweeping pollution from the basin surrounding Mexico City. Thermally driven circulations within the basin, in adjacent valleys, and over the slope of the Mexican Plateau strongly influence winds within the Mexico City basin on the second case day. These wind systems produce a complex interaction of flows, culminating in the propagation of a l-km-deep density current circulation through Mexico City that displaces the polluted basin air mass aloft. Regional northeasterly flows develop early in the morning of the third case day and force the polluted basin air mass toward the southwestern portion of the basin where observed ozone concentrations are highest. The results show that both regional and synoptic-scale hows influence the meteorology within the Mexico City basin over the 3-day period. The simulated circulations also provide a physical basis for understanding the high spatial and temporal variability of ozone concentrations observed over the city. RP Bossert, JE (reprint author), LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,MS-D401,EES-5,LOS ALAMOS,NM 87545, USA. NR 30 TC 50 Z9 50 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8763 J9 J APPL METEOROL JI J. Appl. Meteorol. PD FEB PY 1997 VL 36 IS 2 BP 119 EP 140 DI 10.1175/1520-0450(1997)036<0119:AIOFRA>2.0.CO;2 PG 22 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WE478 UT WOS:A1997WE47800002 ER PT J AU Sellers, CH Hyde, TA Branagan, DJ Lewis, LH Panchanathan, V AF Sellers, CH Hyde, TA Branagan, DJ Lewis, LH Panchanathan, V TI Microstructure and magnetic properties of inert gas atomized rare earth permanent magnetic materials SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID FE; POWDERS AB Several permanent magnet alloys based on the ternary Nd2Fe14B (2-14-1) composition have been prepared by inert gas atomization (IGA). The microstructure and magnetic properties of these alloys have been studied as a function of particle size, both before and after heat treatment. Different particle sizes have characteristic properties due to the differences in cooling rate experienced during solidification from the melt. These properties are also strongly dependent on the alloy composition due to the cooling rate's effect on the development of the phase structure; the use of rare earth rich compositions appears necessary to compensate for a generally inadequate cooling rate. After atomization, a brief heat treatment is necessary for the development of the optimal microstructure and magnetic properties, as seen from the hysteresis loop shape and improvements in key magnetic parameters (intrinsic coercivity H-ci, remanence B-r, and maximum energy product BHmax). By adjusting alloy compositions specifically for this process, magnetically isotropic powders with good magnetic properties can be obtained and opportunities for the achievement of better properties appear to be possible. (C) 1997 American Institute of Physics. C1 BROOKHAVEN NATL LAB,DEPT APPL SCI,DIV MAT SCI,UPTON,NY 11973. MAGNEQUENCH INT,ANDERSON,IN 46013. RP Sellers, CH (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83402, USA. NR 16 TC 10 Z9 10 U1 0 U2 3 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 FEB 1 PY 1997 VL 81 IS 3 BP 1351 EP 1357 DI 10.1063/1.363871 PG 7 WC Physics, Applied SC Physics GA WF017 UT WOS:A1997WF01700052 ER PT J AU Tolt, ZL Heatherly, L Clausing, RE Feigerle, CS AF Tolt, ZL Heatherly, L Clausing, RE Feigerle, CS TI The role of H2O in enhancing hot filament assisted diamond growth at low temperatures SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; THERMAL-DESORPTION; MICROWAVE PLASMA; HYDROGEN; OXYGEN; OXIDATION; WATER; SPECTROSCOPY; KINETICS; SURFACES AB The addition of a small amount of oxygen to a hot filament assisted chemical vapor deposition reactor allows diamond to be deposited at significantly lower filament and substrate temperatures. Scanning electron microscopy and Raman spectroscopy are used to compare films grown with and without oxygen addition as a function of substrate temperature at high and low filament temperatures. Oxygen addition is found to favor growth of high quality diamond at low substrate temperatures (<600 degrees C). The amount of nondiamond carbon is reduced and the clarity and smoothness of facets improves dramatically under these conditions. Equilibrium calculations and residual gas analysis indicate there is H2O in the gas above the substrate during these depositions. The correlation between the dramatic reduction in the nondiamond carbon content of the films and the increased H2O levels near the substrate at low temperatures leads to the conclusion that H2O plays an important role in facilitating deposition at lower temperatures. Potential roles for H2O include terminating carbon dangling bonds by dissociative adsorption and enhancing selective etching of nondiamond carbon by O-2. The gas and surface chemistry of diamond deposition at low temperatures with oxygen addition is also discussed. (C) 1997 American Institute of Physics. C1 UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996. RP Tolt, ZL (reprint author), OAK RIDGE NATL LAB,POB 2008,OAK RIDGE,TN 37831, USA. NR 21 TC 6 Z9 6 U1 1 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 FEB 1 PY 1997 VL 81 IS 3 BP 1536 EP 1545 PG 10 WC Physics, Applied SC Physics GA WF017 UT WOS:A1997WF01700083 ER PT J AU Keim, P Kalif, A Schupp, J Hill, K Travis, SE Richmond, K Adair, DM HughJones, M Kuske, CR Jackson, P AF Keim, P Kalif, A Schupp, J Hill, K Travis, SE Richmond, K Adair, DM HughJones, M Kuske, CR Jackson, P TI Molecular evolution and diversity in Bacillus anthracis as detected by amplified fragment length polymorphism markers SO JOURNAL OF BACTERIOLOGY LA English DT Article ID CEREUS; DNA; DIFFERENTIATION; PX01 AB Bacillus anthracis causes anthrax and represents one of the most molecularly monomorphic bacteria known. We have used AFLP (amplified fragment length polymorphism) DNA markers to analyze 78 B. anthracis isolates and six related Bacillus species for molecular variation. AFLP markers are extremely sensitive to even small sequence variation, using PCR and high-resolution electrophoresis to examine restriction fragments. Using this approach, we examined ca, 6.3% of the Bacillus genome for length mutations and ca. 0.36% for point mutations, Extensive variation was observed among taxa, and both cladistic and phenetic analyses were used to construct a phylogeny of B. anthracis and its closest relatives. This genome-wide analysis of 357 AFLP characters (polymorphic fragments) indicates that B. cereus and B. thuringiensis are the closest taxa to B. anthracis, with B. mycoides slightly more distant. B. subtilis, B. polymyxa, and B. stearothermophilus shared few AFLP markers with B. anthracis and were used as outgroups to root the analysis. In contrast to the variation among taxa, only rare AFLP marker variation was observed within B. anthracis, which may be the most genetically uniform bacterial species known. However, AFLP markers did establish the presence or absence of the pXO1 and pX02 plasmids and detected 31 polymorphic chromosomal regions among the 79 B. anthracis isolates. Cluster analysis identified two very distinct genetic lineages among the B. anthracis isolates. The level of variation and its geographic distribution are consistent with a historically recent African origin for this pathogenic organism. Based on AFLP marker similarity, the ongoing anthrax epidemic in Canada and the northern United States is due to a single strain introduction that has remained stable over at least 30 years and a 1,000-mile distribution. C1 NO ARIZONA UNIV,DEPT SCI BIOL,FLAGSTAFF,AZ 86011. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LOUISIANA STATE UNIV,SCH VET MED,DEPT EPIDEMIOL & COMMUNITY HLTH,BATON ROUGE,LA 70803. RI Keim, Paul/A-2269-2010 NR 25 TC 253 Z9 269 U1 1 U2 5 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD FEB PY 1997 VL 179 IS 3 BP 818 EP 824 PG 7 WC Microbiology SC Microbiology GA WE440 UT WOS:A1997WE44000033 PM 9006038 ER PT J AU Xu, YR Mortimer, MW Fisher, TS Kahn, ML Brockman, FJ Xun, LY AF Xu, YR Mortimer, MW Fisher, TS Kahn, ML Brockman, FJ Xun, LY TI Cloning, sequencing, and analysis of a gene cluster from Chelatobacter heintzii ATCC 29600 encoding nitrilotriacetate monooxygenase and NADH:Flavin mononucleotide oxidoreductase SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SP STRAIN IGTS8; PYRUVATE-DEHYDROGENASE COMPLEX; ESCHERICHIA-COLI; NUCLEOTIDE-SEQUENCE; MOLECULAR CHARACTERIZATION; PRISTINAMYCIN-IIB; BACTERIA; DESULFURIZATION; IDENTIFICATION; PROTEINS AB Nitrilotriacetate (NTA) is an important chelating agent in detergents and has also been used extensively in processing radionuclides. In Chelatobacter heintzii ATCC 29600, biodegradation of NTA is initiated by NTA monooxygenase that oxidizes NTA to iminodiacetate and glyoxylate. The NTA monooxygenase activity requires two component proteins, component A and component B, but the function of each component is unclear, We hale cloned and sequenced a gene cluster encoding components A and B (nmoA and nmoB) and two additional open reading frames, nmoR and nmoT; donnstream of nmo.4. Based on sequence similarities, nmoR and nmoT probably encode a regulatory protein and a transposase, respectively, The NmoA sequence was similar to a monooxygenase that uses reduced flavin mononucleotide (FMNH(2)) as reductant; NmoB was similar to an NADH:flavin mononucleotide (FMN) oxidoreductase, On the basis of this information, ne tested the function of each component, Purified component B was shown to be an NADH:FMN oxidoreductase, and its activity could be separated from that of component A, When the Photobacterium fischeri NADH:FMN oxidoreductase was substituted for component B in the complete reaction, NTA was oxidized, showing that the substrate specificity of the reaction resides in component A, Component a is therefore an NTA monooxygenase that uses FMNH(2) and O-2 to oxidize NTA, and component B is an NADH:FMN oxidoreductase that provides FMNH(2) for NTA oxidation. C1 WASHINGTON STATE UNIV, DEPT MICROBIOL, RICHLAND, WA 99352 USA. PACIFIC NW LAB, ENVIRONM MICROBIOL GRP, RICHLAND, WA 99352 USA. WASHINGTON STATE UNIV, DEPT MICROBIOL, PULLMAN, WA 99164 USA. WASHINGTON STATE UNIV, INST BIOL CHEM, PULLMAN, WA 99164 USA. NR 49 TC 64 Z9 69 U1 0 U2 6 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD FEB PY 1997 VL 179 IS 4 BP 1112 EP 1116 PG 5 WC Microbiology SC Microbiology GA WG582 UT WOS:A1997WG58200018 PM 9023192 ER PT J AU Martin, RB Gibson, VA Stover, SM Gibeling, JC Griffin, LV AF Martin, RB Gibson, VA Stover, SM Gibeling, JC Griffin, LV TI Residual strength of equine bone is not reduced by intense fatigue loading: Implications for stress fracture SO JOURNAL OF BIOMECHANICS LA English DT Article DE fatigue; damage; elastic modulus; strength; racehorse ID 3RD METACARPAL BONE; DAMAGE ACCUMULATION; COMPACT BONE; RACEHORSES; REPAIR; STRAIN; HORSE; LIFE AB Fatigue or stress fractures are an important clinical problem in humans as well as racehorses. An important question in this context is, when a bone experiences fatigue damage during extreme use, how much is it weakened compared to its original state? Since there are very limited data on this question and stress fractures are common in racehorses, we sought to determine the effect of fatigue loading on the monotonic strength of equine cortical bone. Beams were machined from the dorsal, medial and lateral cortices of the third metacarpal bones of six thoroughbred racehorses. Beams from left and right bones were assigned to control and fatigue groups, respectively (N = 18 each). The fatigue group was cyclically loaded in three-point bending at 2 Hz for 100,000 cycles at 0-5000 microstrain while submerged in saline at 37 degrees C. These beams, as well as those in the control group, were then monotonically loaded to failure in three-point bending. The monotonic load-deflection curves were analyzed for differences using three-factor (fatigue loading, anatomic region, and horse) analysis of variance. The mean failure load was 3% less in the fatigue group, but this reduction was only marginally significant. Neither elastic modulus nor yield strength was significantly affected by the fatigue loading. The principal effects of Fatigue loading were on post-yield behavior (yield being based on a 0.02% offset criterion). The work done and the load increase between yield and failure were both significantly reduced. All the variables except post-yield deflection were significantly affected by anatomic region. In summary, loading equivalent to a lifetime of racing does not significantly weaken equine cortical bone ex vivo. The clinical implication of this may be that the biological repair of fatigue damage can actually contribute to stress fracture if pressed too far. Copyright (C) 1996 Elsevier Science Ltd. C1 LAWRENCE LIVERMORE NATL LAB,SCH MED,ORTHOPED RES LABS,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,SCH VET MED,ORTHOPED RES LAB,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,COLL ENGN,DEPT CHEM ENGN & MAT SCI,DAVIS,CA 95616. FU NIAMS NIH HHS [AR41644] NR 24 TC 38 Z9 38 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9290 J9 J BIOMECH JI J. Biomech. PD FEB PY 1997 VL 30 IS 2 BP 109 EP 114 DI 10.1016/S0021-9290(96)00113-3 PG 6 WC Biophysics; Engineering, Biomedical SC Biophysics; Engineering GA WC304 UT WOS:A1997WC30400002 PM 9001930 ER PT J AU Griffin, LV Gibeling, JC Gibson, VA Martin, RB Stover, SM AF Griffin, LV Gibeling, JC Gibson, VA Martin, RB Stover, SM TI Artifactual nonlinearity due to wear grooves and friction in four-point bending experiments of cortical bone SO JOURNAL OF BIOMECHANICS LA English DT Article DE flexural testing; finite element modeling; friction; wear grooves; loading artifacts ID BEHAVIOR AB Experiments and analyses were performed to determine the cause of a nonlinear force-deflection response observed in four-point flexural fatigue of beams of cortical bone machined from the mid-diaphysis of the equine third metacarpus. Observable grooves which formed on the beam surface at supports and load noses were found to be the primary cause of the nonlinearity. An additional geometric nonlinearity at large deflections revealed by finite element modeling may be minimized by using the smallest diameter supports and load noses recommended in ASTM 790. However, frictional constraint of the beams at the load noses and supports can occur at low load levels and should be avoided by using roller-bearing supports and load noses, or some equivalent method. Copyright (C) 1996 Elsevier Science Ltd. C1 LAWRENCE LIVERMORE NATL LAB,COLL ENGN,DIV MAT SCI & ENGN,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,SCH MED,ORTHOPAED RES LABS,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,SCH VET MED,VET ORTHOPED RES LAB,DAVIS,CA 95616. FU NIAMS NIH HHS [AR41644] NR 8 TC 6 Z9 6 U1 1 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0021-9290 J9 J BIOMECH JI J. Biomech. PD FEB PY 1997 VL 30 IS 2 BP 185 EP 188 DI 10.1016/S0021-9290(96)00124-8 PG 4 WC Biophysics; Engineering, Biomedical SC Biophysics; Engineering GA WC304 UT WOS:A1997WC30400011 PM 9001939 ER PT J AU Tang, IN Fung, KH AF Tang, IN Fung, KH TI Hydration and Raman scattering studies of levitated microparticles: Ba(NO(3))(2), Sr(NO3)(2), and Ca(NO3)(2) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID AEROSOL-PARTICLES; LIQUID WATER; SOLUTION DROPLETS; SPECTROSCOPY; SULFATES; PRESSURES; NITRATES AB The phase transformation and hydration of inorganic salt particles composed of alkaline earth metal nitrates, Ba(NO3)(2), Sr(NO3)(2), and Ca(NO3)(2) are investigated in a quadrupole cell, in which a levitated single microparticle is in dynamic equilibrium with water vapor under controlled humidity conditions. Laser Raman and Mie scattering techniques are used to probe the chemical and physical states of the microparticle before and after phase transformation. Because of the high degree of supersaturation that only a suspended solution droplet can attain before solidifying, metastable states not predicted from bulk solution thermodynamics often result. Thus it is found that, except for Ba(NO3)(2) particles which form the stable anhydrous crystalline state upon efflorescence, Sr(NO3)(2) and Ca(NO3)(2) droplets solidify to a metastable amorphous state that contains residual water persisting even in high vacuum. Raman spectra of the amorphous particles reveal that the nitrate ions form contact-ion pairs with the bivalent cations and that the residual water molecules possess very little, if any, hydrogen bond characteristics. The deliquescence properties of the amorphous particles, which are found to be different from those expected of the bulk crystalline states, are also reported. (C) 1997 American Institute of Physics. RP Tang, IN (reprint author), BROOKHAVEN NATL LAB, DEPT APPL SCI, ENVIRONM CHEM DIV, UPTON, NY 11973 USA. NR 42 TC 89 Z9 92 U1 1 U2 22 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 FEB 1 PY 1997 VL 106 IS 5 BP 1653 EP 1660 DI 10.1063/1.473318 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF645 UT WOS:A1997WF64500001 ER PT J AU Kaiser, RI Ochsenfeld, C HeadGordon, M Lee, YT Suits, AG AF Kaiser, RI Ochsenfeld, C HeadGordon, M Lee, YT Suits, AG TI Crossed-beam reaction of carbon atoms with hydrocarbon molecules .3. Chemical dynamics of propynylidyne (l-C3H; X(2)II(j)) and cyclopropynylidyne (c-C3H; X(2)B(2)) formation from reaction of C(P-3(j)) with acetylene, C2H2(X(1)Sigma(+)(g))1 Sigma+g) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID COUPLED-CLUSTER METHODS; GAUSSIAN-BASIS SETS; SHELL HARTREE-FOCK; MICROWAVE-SPECTRUM; ENERGY GRADIENTS; LINEAR C3H; CHEMISTRY; RADICALS; CONSTANTS; RATES AB The reaction between ground state carbon atoms, C(P-3(j)), and acetylene, C2H2(X(1) Sigma(g)(+)), is studied at three collision energies between 8.8 and 45.0 kJ mol(-1) using the crossed molecular beams technique. Product angular distributions and time-of-flight spectra of C3H at m/e = 37 are recorded. Forward-convolution fitting of the data yields weakly polarized center-of-mass angular flux distributions decreasingly forward scattered with respect to the carbon beam as the collision energy rises from 8.8 to 28.0 kJ mol(-1), and isotropic at 45.0 kJ mol(-1). Reaction dynamics inferred from the experimental data and ab initio calculations on the triplet C3H2 and doublet C3H potential energy surface suggest two microchannels initiated by addition of C(P-3(j)) either to one acetylenic carbon to form s-trans propenediylidene or to two carbon atoms to yield triplet cyclopropenylidene via loose transition states located at their centrifugal barriers. Propenediylidene rotates around its B/C axis and undergoes [2,3]-H-migration to propargylene, followed by C-H bond cleavage via a symmetric exit transition state to l-C3H(X (2) parallel to(j)) and H. Direct stripping dynamics contribute to the forward-scattered second microchannel to form c-C3H(X B-2(2)) and H. This contribution is quenched with rising collision energy. The explicit identification of l-C3H(X (2) Pi(j)) and c-C3H(X B-2(2)) under single collision conditions represents a one-encounter mechanism to build up hydrocarbon radicals in the interstellar medium and resembles a more realistic synthetic route to interstellar C3H isomers than hitherto postulated ion-molecule reactions. Relative reaction cross sections to the linear versus cyclic isomer correlate with actual astronomical observations and explain a higher [c-C3H]/[l-C3H] ratio in the molecular cloud TMC-1 (approximate to 1) as compared to the circumstellar envelope surrounding the carbon star IRC+10216 (approximate to 0.2) via the atom-neutral reaction C(P-3(j))+C2H2(X C-1(g)+). (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. RP Kaiser, RI (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. RI Lee, Yuan-Tseh/F-7914-2012; Ochsenfeld, Christian/E-8021-2015 OI Ochsenfeld, Christian/0000-0002-4189-6558 NR 60 TC 77 Z9 77 U1 1 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 FEB 1 PY 1997 VL 106 IS 5 BP 1729 EP 1741 DI 10.1063/1.474092 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF645 UT WOS:A1997WF64500009 ER PT J AU Taatjes, CA AF Taatjes, CA TI Association and isotopic exchange reactions of CH(CD)[X(2)Pi]+CO SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FLASH KINETIC SPECTROSCOPY; THEORETICAL-ANALYSIS; TRANSITION-STATE; TEMPERATURE; CH; DEPENDENCE; ISOMERIZATION; DISSOCIATION; COMBUSTION; RADICALS AB The reaction rates for (CH)-C-12 and (CD)-C-12 With normal isotopic abundance CO and (CO)-C-13 have been studied at 293 K for pressures between 12.5 and 500 Torr and at 100 Torr for temperatures between 293 and 650 K. The pressure and temperature dependence of the addition reaction of CH with CO have been measured. The addition rate coefficient can be fit to the expression 7.2+/-0.3x10(-12) (T/293)(-2.4+/-0.2) cm(3) molecule(-1) s(-1) at 100 Torr total pressure (He buffer). A fit of the pressure dependence to a Tree expression with F-c=0.6 yields a low-pressure rate constant (k(0)) of 2.4+/-0.3x10(-30) cm(6) molecule(-2) s(-1). The rate for carbon atom exchange has been measured by comparison of the C-13 labeled and unlabeled reaction rates. The isotopic exchange reaction is 1.0+/-0.2x10(-12) cm(3) molecule(-1) s(-1) at 20 Torr. The deuterium isotope effect on the exchange rate is large, with an inverse kinetic isotope effect (k(H)/k(D))=0.28+/-0.08 at 20 Torr. This inverse isotope effect reflects the competition between collisional stabilization and isomerization, and is a convolution of isotope effects for the isomerization, unimolecular dissociation, and stabilization rates. The experimental results are consistent with a mechanism for exchange that involves isomerization of an HCCO adduct via an oxiryl intermediate, and indicate that insertion into the C-O bond is not important in this reaction. (C) 1997 American Institute of Physics. RP Taatjes, CA (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,MAIL STOP 9055,LIVERMORE,CA 94551, USA. NR 49 TC 18 Z9 18 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 FEB 1 PY 1997 VL 106 IS 5 BP 1786 EP 1795 DI 10.1063/1.473674 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF645 UT WOS:A1997WF64500016 ER PT J AU Jennison, DR Schultz, PA Sears, MP AF Jennison, DR Schultz, PA Sears, MP TI Ab initio calculations of Ru, Pd, and Ag cluster structure with 55, 135, and 140 atoms SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; METAL-CLUSTERS; ELECTRONIC-STRUCTURE; TRANSITION-METALS; ENERGY; SPECTROSCOPY; ADSORBATE; SYSTEMS; SURFACE; COBALT AB A massively parallel ab initio computer code, which uses Gaussian bases, pseudopotentials, and the local density approximation, permits the study of transition-metal systems with literally hundreds of atoms. We present total energies and relaxed geometries for Ru, Pd, and Ag clusters with N = 55, 135, and 140 atoms. The N = 55 and 135 clusters were chosen because of simultaneous cube-octahedral (fee) and icosahedral (ices) subshell closings, and we find ices geometries are preferred. Remarkably large compressions of the central atoms are observed for the ices structures (up to 6% compared with bulk interatomic spacings), while small core compressions (similar to 1%) are found for the fee geometry. In contrast, large surface compressive relaxations are found for the fee clusters (similar to 2%-3% in average nearest neighbor spacing), while the ices surface displays small compressions (similar to 1%). Energy differences between ices and fee are smallest for Pd, and for all systems the single-particle densities of states closely resembles bulk results. Calculations with N = 134 suggest slow changes in relative energy with N. Noting that the 135-atom fee has a much more open surface than the ices, we also compare N = 140 ices and fee, the latter forming an octahedron with close packed facets. These ices and fee clusters have identical average coordinations and the octahedron is found to be preferred for Ru and Pd but not for Ag. Finally, we compare Harris functional and LDA energy differences on the N = 140 clusters, and find fair agreement only for Ag. C1 SANDIA NATL LABS,PARALLEL COMPUTAT SCI DEPT 9225,ALBUQUERQUE,NM 87185. RP Jennison, DR (reprint author), SANDIA NATL LABS,SURFACE & INTERFACE SCI DEPT 1114,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 40 TC 60 Z9 60 U1 2 U2 9 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 FEB 1 PY 1997 VL 106 IS 5 BP 1856 EP 1862 DI 10.1063/1.473339 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF645 UT WOS:A1997WF64500024 ER PT J AU Nath, SK McCoy, JD Curro, JG Saunders, RS AF Nath, SK McCoy, JD Curro, JG Saunders, RS TI The ordering of symmetric diblock copolymers: A comparison of self-consistent-field and density functional approaches SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTEGRAL-EQUATION THEORY; NONUNIFORM POLYATOMIC SYSTEMS; MOLECULAR-WEIGHT DEPENDENCE; POLYMER-POLYMER INTERFACES; STRONG-SEGREGATION LIMIT; STATE ALKANE MELT; MICROPHASE SEPARATION; BLOCK COPOLYMERS; INHOMOGENEOUS POLYMERS; IMMISCIBLE POLYMERS AB Polymer reference interaction site model (PRISM) based density functional (DF) theory is used to evaluate the structure and thermodynamics of structurally symmetric, freely jointed, diblock chains with 0.50 volume fraction. These results are compared to the results of self-consistent-held (SCF) theory. Agreement between the predictions of the SCF and DF theories is found for the lamella spacing well above the order-disorder transition (ODT) and for the qualitative behavior of the interfacial thickness as a function of both chain length and Flory-Huggins chi parameter. Disagreement is found for the magnitude of the interfacial thickness where DF theory indicates that the thickness is 1.7 +/- 0.2 times larger than that predicted by SCF theory. It appears that behavior on the monomer length scale is sensitive to system specific details which are neglected by SCF theory. (C) 1997 American Institute of Physics. C1 NEW MEXICO INST MIN & TECHNOL,DEPT MAT & MET ENGN,SOCORRO,NM 87801. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RI McCoy, John/B-3846-2010 OI McCoy, John/0000-0001-5404-1404 NR 67 TC 31 Z9 31 U1 0 U2 9 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 FEB 1 PY 1997 VL 106 IS 5 BP 1950 EP 1960 DI 10.1063/1.473332 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF645 UT WOS:A1997WF64500034 ER PT J AU Garrett, WR Zhu, YF AF Garrett, WR Zhu, YF TI Coherent control of multiphoton driven processes: A laser-induced catalyst SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PUMPED STIMULATED EMISSIONS; 3RD-HARMONIC GENERATION; MIXING INTERFERENCE; 3-PHOTON RESONANCE; COOPERATIVE SHIFTS; IONIZATION; EXCITATION; SUPPRESSION; TRANSITIONS; COMPETITION AB A well-known quantum interference phenomenon is combined with laser-induced collisional energy transfer to create a coherently controlled excitation involving two species. From one viewpoint the process involves a laser induced catalyst. An experimental demonstration is performed in mixtures of Xe and Kr gases. (C) 1997 American Institute of Physics. RP Garrett, WR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 32 TC 10 Z9 10 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 FEB 1 PY 1997 VL 106 IS 5 BP 2045 EP 2048 DI 10.1063/1.473311 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WF645 UT WOS:A1997WF64500043 ER PT J AU Zhong, S Doran, JC AF Zhong, S Doran, JC TI A study of the effects of spatially varying fluxes on cloud formation and boundary layer properties using data from the Southern Great Plains Cloud and Radiation Testbed SO JOURNAL OF CLIMATE LA English DT Article ID INHOMOGENEOUS SURFACE FLUXES; MESOSCALE CIRCULATIONS; ATMOSPHERIC FLOW; VEGETATION; LANDSCAPE; MODELS; PARAMETERIZATION; PREDICTION; WEATHER; ENERGY AB Measurements from the Southern Great Plains Cloud and Radiation Testbed site, which is situated in Oklahoma and Kansas and extends over an area approximately 300 km x 350 km in extent, are combined with results from a three-dimensional mesoscale model to study the sensitivity of boundary layer properties to spatially varying surface sensible and latent heat fluxes. Four cloud parameterization schemes are used to estimate the fractional cloudiness expected over the site on three case study days with settled weather conditions during the summer of 1994. Comparisons between observations and model predictions show good qualitative agreement. Although local responses to varying surface fluxes can be found, the replacement of the spatially varying surface conditions with uniform ones makes little difference in the simulated cloud cover or the vertical profiles of potential temperature and water vapor mixing ratio when these are averaged over the full site. Spatial variations in the ambient meteorology were found to be more important than variations in surface fluxes in determining cloud amount and areas of preferred cloud formation. This conclusion is supported by additional simulations in which both the ambient meteorology and surface conditions are averaged over scales ranging from 6.25 km to 300 km. The results call into question the importance of mesoscale fluxes (i.e., fluxes arising from secondary circulations induced by heating contrasts over different surfaces) in coarse-resolution models such as general circulation models, at least for settled weather conditions similar to those considered in this study. C1 PACIFIC NW LAB, EARTH SYST SCI DEPT, RICHLAND, WA 99352 USA. NR 31 TC 25 Z9 25 U1 0 U2 2 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD FEB PY 1997 VL 10 IS 2 BP 327 EP 341 DI 10.1175/1520-0442(1997)010<0327:ASOTEO>2.0.CO;2 PG 15 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA WJ835 UT WOS:A1997WJ83500013 ER PT J AU Scheidegger, AM Lamble, GM Sparks, DL AF Scheidegger, AM Lamble, GM Sparks, DL TI Spectroscopic evidence for the formation of mixed-cation hydroxide phases upon metal sorption on clays and aluminum oxides SO JOURNAL OF COLLOID AND INTERFACE SCIENCE LA English DT Article DE XAFS; sorption; surface precipitation; kinetics ID X-RAY-ABSORPTION; HYDROUS FERRIC-OXIDE; SURFACE PRECIPITATION; AQUEOUS-SOLUTIONS; WATER INTERFACE; FINE-STRUCTURE; ADSORPTION; DESORPTION; KAOLINITE; KINETICS AB Retention of heavy metal ions on soil mineral surfaces is an important process for maintaining environmental quality. A thorough understanding of the kinetics and mechanisms of heavy metal sorption on soil mineral surfaces is therefore of fundamental importance. The present study examines the kinetics and mechanisms of Ni(II) sorption onto pyrophyllite, kaolinite, gibbsite, and montmorillonite. Ni sorption reactions were initially fast (15-40% of the initial Ni was removed within the first hour). Thereafter, the rate of sorption decreased significantly. X-ray absorption fine structure (XAFS) spectroscopy was used to determine the local structural environment of Ni(II). Data analysis reveals the presence of polynuclear Ni surface complexes. Ni-Ni bond distances (3.00-3.03 Angstrom) were distinctly shorter than in Ni(OH)(2)(s) (3.09 Angstrom). We propose that the reduction of the Ni-Ni distances is caused by the formation of mixed Ni/Al hydroxide phases. The XAFS spectra and derived structural parameters are similar to those in takovite (Ni6Al2(OH)(16)CO3 . H2O), thus suggesting the presence of a Ni phase of similar structure. Even though dissolved Al could not be detected in our samples, Al could have been released into solution and incorporated into mixed Ni/Al hydroxide-like phases. The formation of such phases can explain the finding that the dissolution rates (Si-release) are strongly enhanced (relative to the dissolution rates of the clays alone) as long as Ni sorption is pronounced. We suspect that the release of Al into solution is the rate-determining step for the formation of mixed Ni/Al hydroxide-like phases in our study. Our study demonstrates that mixed Ni/Al hydroxide-like compounds can form when Ni is introduced into a suitable environment in which there is a source of hydrolyzed species of Al. One can speculate that the formation of mixed-cation hydroxide compounds also represents a plausible ''sorption mode'' for other divalent metal ions when silicates or oxides are present. It has been shown that similar mixed-cation hydroxide compounds can be synthesized when Mg(II), Ni(II), Co(II), Zn(II), or Mn(II) is added to suspensions containing Al(III), Fe(III), and Cr(III). Thus, the formation of mixed-cation hydroxide compounds should be considered when conducting metal sorption experiments, modeling metal surface complexation, determining speciation, and assessing the risk of the migration of contaminants in polluted sites. (C) 1997 Academic Press C1 BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. RP Scheidegger, AM (reprint author), UNIV DELAWARE, DEPT PLANT & SOIL SCI, NEWARK, DE 19717 USA. NR 52 TC 192 Z9 196 U1 4 U2 46 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9797 EI 1095-7103 J9 J COLLOID INTERF SCI JI J. Colloid Interface Sci. PD FEB 1 PY 1997 VL 186 IS 1 BP 118 EP 128 DI 10.1006/jcis.1996.4624 PG 11 WC Chemistry, Physical SC Chemistry GA WE830 UT WOS:A1997WE83000014 ER PT J AU Dachsel, H Lischka, H Shepard, R Nieplocha, J Harrison, RJ AF Dachsel, H Lischka, H Shepard, R Nieplocha, J Harrison, RJ TI A massively parallel multireference configuration interaction program: The parallel COLUMBUS program SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article ID MOLECULAR ELECTRONIC-STRUCTURE; DISTRIBUTED-MEMORY COMPUTERS; DIRECT SCF; INTEGRAL TRANSFORMATIONS; QUANTUM-CHEMISTRY; IMPLEMENTATION; ALGORITHM; COMPUTATION; ENERGY; SYSTEM AB A massively parallel version of the configuration interaction (CI) section of the COLUMBUS multireference singles and doubles CI (MRCISD) program system is described. In an extension of our previous parallelization work, which was based on message passing, the global. array (GA) toolkit has now been used. For each process, these tools permit asynchronous and efficient access to logical blocks of 1- and 2-dimensional (2-D) arrays physically distributed over the memory of all processors. The GAs are available on most of the major parallel computer systems enabling very convenient portability of our parallel program code. To demonstrate the features of the parallel COLUMBUS CI code, benchmark calculations on selected MRCI and SRCI test cases are reported for the GRAY T3D, Intel Paragon, and IBM SP2. Excellent scaling with the number of processors up to 256 processors (GRAY T3D) was observed. The CI section of a 19 million configuration MRCISD calculation was carried out within 20 min wall clock time on 256 processors of a GRAY T3D. Computations with 38 million configurations were performed recently; calculations up to about 100 million configurations seem possible within the near future. (C) 1997 by John Wiley & Sons, Inc. C1 UNIV VIENNA, INST THEORET CHEM & STRAHLENCHEM, A-1090 VIENNA, AUSTRIA. ARGONNE NATL LAB, DIV CHEM, THEORET CHEM GRP, ARGONNE, IL 60439 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Lischka, Hans/A-8802-2015 NR 57 TC 59 Z9 59 U1 0 U2 3 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 FEB PY 1997 VL 18 IS 3 BP 430 EP 448 DI 10.1002/(SICI)1096-987X(199702)18:3<430::AID-JCC12>3.0.CO;2-M PG 19 WC Chemistry, Multidisciplinary SC Chemistry GA WF660 UT WOS:A1997WF66000012 ER PT J AU Vahedi, V DiPeso, G AF Vahedi, V DiPeso, G TI Simultaneous potential and circuit solution for two-dimensional bounded plasma simulation codes SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID PARTICLE SIMULATION; DISCHARGES; TOOLS; UNIFORMITY AB An algorithm for coupling external circuit elements to be bounded two-dimensional electrostatic plasma simulation codes is developed. In general, the external circuit equations provide a mixture of Dirichlet and Neumann boundary conditions for the Poisson equation, which is solved each time step for the internal plasma potential. We rewrite the coupling between the plasma and the external circuit parameters as an algebraic or ordinary differential equation for the potential on the boundary. This scheme allows decomposition of the field solve into a Laplace solver with boundary conditions (e.g., applied potentials) and a Poisson solver with zero boundary conditions. We present the details of the external circuit coupling to an explicit electrostatic planar two-dimensional particle-in-cell code called PDP2, and discuss briefly how the coupling can be done in an implicit electrostatic code. The decomposition replaces the iterative coupling with a direct coupling and reduces the amount of computational time spent in the field solver. We use PDP2 to simulate a dually excited capacitively coupled RF discharge and show how such a system can be used as a plasma processing tool with separate control over ion flux and ion bombarding energy. (C) 1997 Academic Press. RP Vahedi, V (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 29 TC 75 Z9 76 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD FEB PY 1997 VL 131 IS 1 BP 149 EP 163 DI 10.1006/jcph.1996.5591 PG 15 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WJ865 UT WOS:A1997WJ86500008 ER PT J AU Pfrommer, BG Cote, M Louie, SG Cohen, ML AF Pfrommer, BG Cote, M Louie, SG Cohen, ML TI Relaxation of crystals with the quasi-Newton method SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; PRESSURE; DENSITY; SILICON; PSEUDOPOTENTIALS; SEMICONDUCTORS; TRANSITIONS; PHASES AB A quasi-Newton method is used to simultaneously relax the internal coordinates and lattice parameters of crystals under pressure. The symmetry of the crystal structure is preserved during the relaxation. From the inverse of the Hessian matrix, elastic properties, and some optical phonon frequencies at the Brillouin zone center can be estimated. The efficiency of the method is demonstrated for silicon test systems. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV SCI MAT,BERKELEY,CA 94720. RP Pfrommer, BG (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Cote, Michel/H-3942-2012 OI Cote, Michel/0000-0001-9046-9491 NR 26 TC 827 Z9 856 U1 10 U2 78 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD FEB PY 1997 VL 131 IS 1 BP 233 EP 240 DI 10.1006/jcph.1996.5612 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WJ865 UT WOS:A1997WJ86500014 ER PT J AU Lu, P Li, H Sun, S Tuttle, B AF Lu, P Li, H Sun, S Tuttle, B TI Novel single-solid-source metalorganic chemical vapor processing of PT and PZT thin films SO JOURNAL OF CRYSTAL GROWTH LA English DT Article ID LOW-TEMPERATURE; BUFFER LAYER; DEPOSITION; MEMORIES; GROWTH; PB(ZR AB A novel single-solid-source metalorganic chemical vapor deposition (MOCVD) technique has been developed for the processing of oxide as well as non-oxide thin films. The new technique uses a powder delivery system to deliver the mixed precursor powders directly into a hot vaporizer from room temperature, therefore, avoiding any problems associated with polymerization or decomposition of the precursors before evaporation. The technique simplifies MOCVD processing significantly and can greatly improve process reliability and reproducibility. Using the new technique, ferroelectric PbTiO3 (PT) and Pb(ZrxTi1-x)O-3(PZT) thin films have been deposited on (100) MgO and (111)Pt/SiO2/(100) Si substrates. The deposited PT and PZT films have a perovskite structure and are highly oriented with respect to the substrate. Orientation of the PZT films on the Pt substrate is controlled by varying the Pb to (Zr + Ti) ratio in the gas phase. The PT and PZT (x = 0.2) films deposited on the Pt coated substrates have dielectric constants on the order of 200 and 300, respectively, and dielectric loss (tan delta) of about 0.02 to 0.03. These values are comparable to those of solution deposited or sputtered PZT films. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87109. RP Lu, P (reprint author), NEW MEXICO INST MIN & TECHNOL,DEPT MAT SCI & ENGN,SOCORRO,NM 87801, USA. NR 20 TC 7 Z9 7 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD FEB PY 1997 VL 171 IS 3-4 BP 453 EP 457 DI 10.1016/S0022-0248(96)00659-8 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA WF409 UT WOS:A1997WF40900018 ER PT J AU Gooding, CM Choudary, PV AF Gooding, CM Choudary, PV TI Rapid and sensitive immunomagnetic separation-polymerase chain reaction method for the detection of Escherichia coli O157:H7 in raw milk and ice-cream SO JOURNAL OF DAIRY RESEARCH LA English DT Article ID O157; INFECTION; SAMPLES; FOODS AB Escherichia coli O157:H7 in spiked samples of raw milk and ice-cream was enriched in tryptic soy broth for 4 h, captured by immunomagnetic separation, subjected to amplification by polymerase chain reaction of parts of the verotoxin genes (SLT-I and SLT-II), and detected by agarose gel electrophoresis. Using this method, as few as 1 cfu Esch. coli O157:H7/g food could be detected in < 10 h. C1 LAWRENCE LIVERMORE NATL LAB, CIFAR, ANTIBODY ENGN LAB, DAVIS, CA 95616 USA. LAWRENCE LIVERMORE NATL LAB, DEPT ENTOMOL, DAVIS, CA 95616 USA. OI Choudary, Prabhakara/0000-0002-7163-6466 NR 17 TC 36 Z9 39 U1 0 U2 1 PU CAMBRIDGE UNIV PRESS PI NEW YORK PA 40 WEST 20TH STREET, NEW YORK, NY 10011-4211 SN 0022-0299 J9 J DAIRY RES JI J. Dairy Res. PD FEB PY 1997 VL 64 IS 1 BP 87 EP 93 DI 10.1017/S0022029996001896 PG 7 WC Agriculture, Dairy & Animal Science; Food Science & Technology SC Agriculture; Food Science & Technology GA WH646 UT WOS:A1997WH64600009 PM 9120079 ER PT J AU Dinar, A Howitt, RE AF Dinar, A Howitt, RE TI Mechanisms for allocation of environmental control cost: Empirical tests of acceptability and stability SO JOURNAL OF ENVIRONMENTAL MANAGEMENT LA English DT Article DE allocation schemes; game theory allocations; drainage water pollution; San Joaquin Valley ID IRRIGATION; GAME AB This paper evaluates schemes for allocation of joint environmental control cost among polluters using, as an example, the drainage pollution problem of the San Joaquin Valley of California. The analysis is conducted by comparing cost allocation schemes' performance in a regional context. Different schemes (proportional allocation, Nash-Harsanyi, allocation according to marginal cost, Shapley, the nucleolus and the Separable Cost Remaining Benefit principle) are used to allocate regional joint environmental control costs under two extreme states of nature scenarios, resulting in different pollution flows. The results provide clear empirical evidence that regional arrangements may vary with state of nature. Another important result is that the different allocation schemes have different outcomes in terms of their acceptability to the players, and in terms of their derived stability, as measured by the Shapley-Shubik Power Index, and by the Propensity to Disrupt. Therefore, implementation of environmental policy should also be examined based on its long-term sustainability, and taking into consideration only the cost recovery aspect. (C) 1997 Academic Press Limited. C1 LAWRENCE LIVERMORE NATL LAB, DEPT AGR ECON, DAVIS, CA 95616 USA. RP Dinar, A (reprint author), WORLD BANK, AGR & NAT RESOURCES DEPT, 1818 H ST NW, ROOM 5-8039, WASHINGTON, DC 20433 USA. NR 28 TC 48 Z9 52 U1 2 U2 6 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0301-4797 EI 1095-8630 J9 J ENVIRON MANAGE JI J. Environ. Manage. PD FEB PY 1997 VL 49 IS 2 BP 183 EP 203 DI 10.1006/jema.1995.0088 PG 21 WC Environmental Sciences SC Environmental Sciences & Ecology GA WL792 UT WOS:A1997WL79200003 ER PT J AU Gary, SP Thomsen, MF Lee, J McComas, DJ Moore, KR AF Gary, SP Thomsen, MF Lee, J McComas, DJ Moore, KR TI Warm protons at geosynchronous orbit SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ION-CYCLOTRON WAVES; PITCH-ANGLE DISTRIBUTIONS; MAGNETOSPHERIC PLASMA ANALYZER; EQUATORIALLY TRAPPED IONS; EARTHS MAGNETIC EQUATOR; LOW-FREQUENCY WAVES; RING CURRENT; HEAVY-IONS; PARTICLE INTERACTIONS; OUTER PLASMASPHERE AB Ions in the outer magnetosphere typically are observed to consist of a hot (T similar to 10 keV) component and a cool constituent with energies of a few eV. The hot component often is observed to be anisotropic with T-perpendicular to > T-parallel to, where the subscripts denote directions relative to the background magnetic field, whereas the cool ions exhibit a wide variety of anisotropies. The Los Alamos magnetospheric plasma analyzer (MPA) instruments measure ion and electron velocity distributions from about 1 eV to about 40 keV at geosynchronous orbit. In the afternoon and evening sectors MPA observations show that cool ions, which are assumed to be protons, are sometimes ''warm'' with temperatures of order 10 eV and T-perpendicular to > T-parallel to. Theory and simulations of the electromagnetic proton cyclotron instability, which is driven by the hot proton anisotropy, have shown that the resulting enhanced field fluctuations heat initially cool protons. Moreover, this process implies a scaling relation for the apparent temperature of the warm protons as a function of the relative densities of the two components. This manuscript describes an examination of MPA data which shows that this scaling relation provides an approximate upper bound for a selected set of warm proton temperatures observed at geosynchronous orbit. This result is consistent with the hypothesis that the proton cyclotron instability is an important energization source for warm protons at geosynchronous orbit. RP Gary, SP (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 74 TC 4 Z9 4 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1997 VL 102 IS A2 BP 2291 EP 2300 DI 10.1029/96JA03048 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF648 UT WOS:A1997WF64800027 ER PT J AU Birn, J Thomsen, MF Borovsky, JE Reeves, GD McComas, DJ Belian, RD AF Birn, J Thomsen, MF Borovsky, JE Reeves, GD McComas, DJ Belian, RD TI Characteristic plasma properties during dispersionless substorm injections at geosynchronous orbit SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID ENERGETIC PARTICLE MEASUREMENTS; PROTON DRIFT ECHOES; MAGNETOSPHERIC SUBSTORMS; SYNCHRONOUS ORBIT; ION-ACCELERATION; ELECTRIC-FIELDS; SHEET; CONVECTION; DYNAMICS; ONSET AB The substorm-associated behavior of the thermal plasma (30 eV < E < 40 keV) in the plasma sheet is examined by means of a superposed epoch analysis, using a full year of data from a spacecraft in geosynchronous orbit. The zero epoch time is taken to be substorm onset as indicated by a dispersionless energetic particle injection observed on the same spacecraft. Five classes of injection events are found to be well ordered by their average local times. These range from pure ion injections similar to 3 hours prior to local midnight, to ion injections followed a few minutes later by an electron injection similar to 2 hours before midnight, to simultaneous ion and electron injections close to midnight, to electron injections that are followed by an ion injection similar to 1 hour postmidnight, and finally to pure electron injections similar to 2 hours postmidnight. The thermal electrons show a significant increase in temperature (from similar to 1 to similar to 2 keV) and pressure at substorm onset, while the density and the thermal ion signatures (below similar to 30 keV) are typically weak and may even vary with local time. However, energetic ions (above similar to 30 keV), which contribute significantly to the total ion pressure, show clear flux enhancements, leading to a rise in the total temperature from similar to 10 to similar to 16 keV, Preexisting perpendicular anisotropies in the thermal electrons are reduced during the substorm growth phase but become enhanced again after onset, sometimes after a brief period of parallel anisotropy. Similar anisotropy signatures are found for the thermal ions, although somewhat less pronounced. RP Birn, J (reprint author), LOS ALAMOS NATL LAB, MS D436, LOS ALAMOS, NM 87545 USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 48 TC 122 Z9 124 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1997 VL 102 IS A2 BP 2309 EP 2324 DI 10.1029/96JA02870 PG 16 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF648 UT WOS:A1997WF64800029 ER PT J AU Birn, J Thomsen, MF Borovsky, JE Reeves, GD McComas, DJ Belian, RD Hesse, M AF Birn, J Thomsen, MF Borovsky, JE Reeves, GD McComas, DJ Belian, RD Hesse, M TI Substorm ion injections: Geosynchronous observations and test particle orbits in three-dimensional dynamic MHD fields SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID MAGNETOSPHERIC PLASMA ANALYZER; SHEET BOUNDARY-LAYER; MAGNETOTAIL RECONNECTION; MAGNETIC RECONNECTION; CURRENT DISRUPTION; CURRENT WEDGE; NEUTRAL LINE; ACCELERATION; ONSET; MODEL AB We investigate particle acceleration and the flux increases associated with substorm particle injections using geosynchronous observations and test proton orbits in the dynamic fields of a three-dimensional MHD simulation of neutral line formation and dipolarization in the magnetotail. The energetic particle flux changes obtained from the test particle orbits agree well with observations that demonstrate rapid ion flux increases at energies above similar to 20 keV but little change at lower energies. The ''injection region'' inferred from the test particles not only has a sharp earthward boundary (the usual injection boundary) but also a sharp but ragged tailward boundary. The earthward portion of enhanced ion flux can be traced to the enhanced cross-tail electric field associated with the collapse and dipolarization of the inner tail, whereas the tailward edge is closely associated with the near-Earth x-type neutral line. Because of the rapid earthward motion of accelerated ions away from the neutral line, this boundary is displaced earthward to where the energetic ions become more adiabatic in the stronger dipolar field. Lower-energy ions are not affected by cross-tail acceleration in the strong E(y) fields because their earthward ExB drift dominates the cross-tail drift, except very close to the neutral line. C1 NASA, GODDARD SPACE FLIGHT CTR, GREENBELT, MD 20771 USA. RP LOS ALAMOS NATL LAB, MS D466, LOS ALAMOS, NM 87545 USA. RI Hesse, Michael/D-2031-2012; Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 54 TC 101 Z9 101 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9380 EI 2169-9402 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1997 VL 102 IS A2 BP 2325 EP 2341 DI 10.1029/96JA03032 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF648 UT WOS:A1997WF64800030 ER PT J AU Convery, PD Gary, SP AF Convery, PD Gary, SP TI Electromagnetic proton cyclotron ring instability: Threshold and saturation SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID COMET GRIGG-SKJELLERUP; PLASMA INSTABILITY; ION INSTABILITIES; NEUTRAL SHEET; WAVES DRIVEN; ULF WAVES; BOW SHOCK; SPACE; DISTRIBUTIONS; NONGYROTROPY AB This paper describes a theoretical and computational study of the threshold and saturation conditions of the electromagnetic proton cyclotron ring instability. The initial proton velocity distribution is modeled as a Maxwellian in the direction parallel to the ambient magnetic field and as a relatively cold ring in the plane perpendicular to the field. Linear Vlasov theory and one-dimensional hybrid simulations are used to examine and confirm previously derived scaling laws for the maximum instability growth rate and maximum value of the fluctuating magnetic field energy density. Linear theory yields a new instability threshold condition relating the dimensionless ring perpendicular speed and the dimensionless ring parallel temperature. Simulation results show that cessation of fluctuation growth is due to the heating of the ring protons in the parallel direction and to the reduction of the perpendicular kinetic energy of the ring; at saturation these parameters typically lie near values predicted by a linear threshold condition. The threshold condition is predicted to provide an upper bound for proton ring kinetic energies observed in space plasmas. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. NR 36 TC 10 Z9 10 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1997 VL 102 IS A2 BP 2351 EP 2358 DI 10.1029/96JA02951 PG 8 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF648 UT WOS:A1997WF64800032 ER PT J AU LengyelFrey, D Thejappa, G MacDowall, RJ Stone, RG Phillips, JL AF LengyelFrey, D Thejappa, G MacDowall, RJ Stone, RG Phillips, JL TI Ulysses observations of wave activity at interplanetary shocks and implications for type II radio bursts SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID EARTHS BOW SHOCK; SOLAR-WIND; EMISSION MECHANISMS; PLASMA FREQUENCY; FORESHOCK; UPSTREAM; GENERATION; ELECTRONS; REGION; NOISE AB We present the first quantitative investigation of interplanetary type II radio emission in which in situ waves measured at interplanetary shocks are used to compute radio wave intensities for comparison with type II observations. This study is based on in situ measurements of 42 in-ecliptic forward shocks as well as 10 intervals of type II emission observed by the Ulysses spacecraft between 1 AU and 5 AU. The analysis involves comparisons of statistical properties of type II bursts and in situ waves, since the type II events are not related to particular shock passages at Ulysses. Most of the 42 shocks are associated with the occurrence of electrostatic waves near the time of shock passage at Ulysses. These waves, which are identified as electron plasma waves and ion acoustic-like waves, are typically most intense several minutes before shock passage. This suggests that wave-wave interactions might be of importance in electromagnetic wave generation and that type II source regions are located immediately upstream of the shocks. We use the in situ wave measurements to compute type II brightness temperatures, assuming that emission at the fundamental of the electron plasma frequency is generated by the merging of electron plasma waves and ion acoustic waves or the decay of electron plasma waves into ion acoustic and transverse waves. Second harmonic emission is assumed to be produced by the merging of electron plasma waves. The latter mechanism requires that a portion of the electron plasma wave distribution is backscattered, presumably by density inhomogeneities in regions of observed ion acoustic wave activity. The computed type II brightness temperatures are found to be consistent with observed values for both fundamental and second harmonic emission, assuming that strong (similar or equal to 10(-4) V/m) electron plasma waves and ion acoustic waves are coincident and that the electron plasma waves have phase velocities less than about 10 times the electron thermal velocity. Thus a single conversion mechanism provides a plausible scenario for generation of both fundamental and harmonic interplanetary type II emission. C1 NASA, GODDARD SPACE FLIGHT CTR, EXTRATERR PHYS LAB, GREENBELT, MD 20771 USA. NASA, LYNDON B JOHNSON SPACE CTR, HOUSTON, TX 77058 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM USA. RP LengyelFrey, D (reprint author), COMP SCI CORP, 4401 SUITLAND RD, SUITLAND, MD 20746 USA. RI MacDowall, Robert/D-2773-2012 NR 44 TC 25 Z9 25 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0148-0227 J9 J GEOPHYS RES-SPACE JI J. Geophys. Res-Space Phys. PD FEB 1 PY 1997 VL 102 IS A2 BP 2611 EP 2621 DI 10.1029/96JA02871 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WF648 UT WOS:A1997WF64800058 ER PT J AU Sailer, BL Nastasi, AJ Valdez, JG Steinkamp, JA Crissman, HA AF Sailer, BL Nastasi, AJ Valdez, JG Steinkamp, JA Crissman, HA TI Differential effects of deuterium oxide on the fluorescence lifetimes and intensities of dyes with different modes of binding to DNA SO JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY LA English DT Article DE fluorescence lifetime; fluorescence intensity; flow cytometry; DNA-binding fluorochromes; deuterium oxide; apoptosis ID FLOW-CYTOMETRY; RESOLVED FLUORESCENCE; ETHIDIUM-BROMIDE; STRANDED-DNA; CELLS; FLUOROCHROMES; DAPI; ACCESSIBILITY; ENHANCEMENT; PARTICLES AB Deuterium oxide (D2O) increases both the fluorescence lifetime and the fluorescence intensity of the intercalating dyes propidium iodide (PI) and ethidium bromide (EB) when bound to nucleic acid structures. We have used spectroscopic analysis coupled with conventional and phase-sensitive flow cytometry to compare the alterations in intensity and lifetime of various DNA-binding fluorochromes bound to DNA and Chinese hamster ovary (CHO) cells in the presence of D2O vs phosphate-buffered saline (PBS). Spectroscopic and flow cytometric studies showed a differential enhancement of intensity and lifetime based on the mode of fluorochrome-DNA interaction. The fluorescence properties of intercalating probes, such as 7-aminoactinomycin D (7-AAD) and ethidium homodimer II (EthD II) were enhanced to the greatest degree, followed by the probes TOTO and YOYO, and the non-intercalating probes Hoechst 33342 (HO) and 4',6-diamidino-2-phenylindole (DAPI). The non-intercalating probe mithramycin (MI) gave unexpected results, showing a great enhancement of fluorescence intensity and lifetime in D2O, indicating that when staining is performed in PBS, much of the MI fluorescence is quenched by the solvent environment. Apoptotic subpopulations of HL-60 cells had a shorter lifetime compared to non-apoptotic subpopulations when stained with EthD II. These results indicate that accessibility of the dye molecules to the solvent environment, once bound to DNA, leads to the differential enhancement effects of D2O on fluorescence intensity and lifetime of these probes. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. FU NCRR NIH HHS [P41-RR01315, R01RR07855, RR06758] NR 36 TC 28 Z9 29 U1 1 U2 7 PU HISTOCHEMICAL SOC INC PI SEATTLE PA UNIV WASHINGTON, DEPT BIOSTRUCTURE, BOX 357420, SEATTLE, WA 98195 SN 0022-1554 J9 J HISTOCHEM CYTOCHEM JI J. Histochem. Cytochem. PD FEB PY 1997 VL 45 IS 2 BP 165 EP 175 PG 11 WC Cell Biology SC Cell Biology GA WM757 UT WOS:A1997WM75700003 PM 9016307 ER PT J AU Knapp, RB Faison, BD AF Knapp, RB Faison, BD TI A bioengineering system for in situ bioremediation of contaminated groundwater SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE in situ bioremediation; biostimulation; bioaugmentation; bioengineering; subsurface systems ID INSITU BIODEGRADATION; CHLORINATED ETHENES; FIELD-EVALUATION; TRANSPORT; BACTERIA; FILTER; MODEL; PHASE AB Much of the past and current focus of bioremediation has been on laboratory studies of microbial processes. By necessity, early studies have ignored important field properties, parameters, and processes that control the ultimate success of in situ bioremediation of contaminated groundwater. This paper presents a bioengineering systems approach that examines the impact of some of these field variables on common bioremediation practices. Using simple systems, the niche of biostimulation is shown to be aquifers with high contaminant sorption. A novel gasphase biostimulation filter and a novel resting-state bioaugmentation/biofilter approach which show promise for effective field implementation are discussed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Knapp, RB (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,L206,LIVERMORE,CA 94551, USA. NR 27 TC 11 Z9 11 U1 0 U2 2 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0169-4146 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD FEB-MAR PY 1997 VL 18 IS 2-3 BP 189 EP 197 DI 10.1038/sj.jim.2900321 PG 9 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WU511 UT WOS:A1997WU51100014 PM 9134766 ER PT J AU Pfiffner, SM Palumbo, AV Phelps, TJ Hazen, TC AF Pfiffner, SM Palumbo, AV Phelps, TJ Hazen, TC TI Effects of nutrient dosing on subsurface methanotrophic populations and trichloroethylene degradation SO JOURNAL OF INDUSTRIAL MICROBIOLOGY & BIOTECHNOLOGY LA English DT Article DE in situ bioremediation; subsurface; methanotrophs; TCE; nutrient availability ID CHLORINATED ETHENES; BIODEGRADATION; MINERALIZATION; BIOTRANSFORMATION; BIOREMEDIATION; BIOSTIMULATION; BACTERIUM; SITE AB In in situ bioremediation demonstration at the Savannah River Site in Aiken, South Carolina, trichloroethylene-degrading microorganisms were stimulated by delivering nutrients to the TCE-contaminated subsurface via horizontal injection wells, Microbial and chemical monitoring of groundwater from 12 vertical wells was used to examine the effects of methane and nutrient (nitrogen and phosphorus) dosing on the methanotrophic populations and on the potential of the subsurface microbial communities to degrade TCE. Densities of methanotrophs increased 3-5 orders of magnitude during the methane- and nutrient-injection phases; this increase coincided with the higher methane levels observed in the monitoring wells, TCE degradation capacity, although not directly tied to methane concentration, responded to the methane injection, and responded more dramatically to the multiple-nutrient injection. These results support the crucial role of methane, nitrogen, and phosphorus as amended nutrients in TCE bioremediation. The enhancing effects of nutrient dosing on microbial abundance and degradative potentials, coupled with increased chloride concentrations, provided multiple lines of evidence substantiating the effectiveness of this integrated in situ bioremediation process. C1 OAK RIDGE NATL LAB, DIV ENVIRONM SCI, OAK RIDGE, TN 37831 USA. WESTINGHOUSE SAVANNAH RIVER CO, SAVANNAH RIVER TECHNOL CTR, AIKEN, SC USA. RI Palumbo, Anthony/A-4764-2011; phelps, tommy/A-5244-2011; Hazen, Terry/C-1076-2012 OI Palumbo, Anthony/0000-0002-1102-3975; Hazen, Terry/0000-0002-2536-9993 NR 38 TC 30 Z9 30 U1 0 U2 4 PU SPRINGER HEIDELBERG PI HEIDELBERG PA TIERGARTENSTRASSE 17, D-69121 HEIDELBERG, GERMANY SN 1367-5435 J9 J IND MICROBIOL BIOT JI J. Ind. Microbiol. Biotechnol. PD FEB-MAR PY 1997 VL 18 IS 2-3 BP 204 EP 212 DI 10.1038/sj.jim.2900350 PG 9 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA WU511 UT WOS:A1997WU51100016 PM 9134767 ER PT J AU DeGraw, JI Colwell, WT Jue, T AF DeGraw, JI Colwell, WT Jue, T TI Synthesis of Edatrexate (2-C-13-glutamate) SO JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS LA English DT Article DE Edatrexate; antitumor; C-13-magnetic resonance spectroscopy ID METASTATIC BREAST-CANCER; PHASE-II; CHEMOTHERAPY AB The experimental antitumor drug Edatrexate, labeled with 99% C-13 at the 2-position of the glutamate acid group was required for C-13-magnetic resonance spectroscopy studies in biological media. Coupling of 2,4-diamino-4-deoxy-10-ethyl-10-deazapteroic acid with diethyl L-2-C-13-glutamate as promoted by BOP reagent afforded Edatrexate (2-C-13-glu) diethyl ester in 60% yield following purification by column chromatography. Saponification by aqueous NaOH in 2-methoxyethanol gave the target molecule in 44% yield or 26% overall. C1 LAWRENCE LIVERMORE NATL LAB,DEPT BIOL CHEM,DAVIS,CA 95616. RP DeGraw, JI (reprint author), SRI INT,BIOORGAN CHEM LAB,333 RAVENSWOOD AVE,MENLO PK,CA 94025, USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0362-4803 J9 J LABELLED COMPD RAD JI J. Label. Compd. Radiopharm. PD FEB PY 1997 VL 39 IS 2 BP 99 EP 103 PG 5 WC Biochemical Research Methods; Chemistry, Medicinal; Chemistry, Analytical SC Biochemistry & Molecular Biology; Pharmacology & Pharmacy; Chemistry GA WH623 UT WOS:A1997WH62300001 ER PT J AU Kresin, V Wolf, S Ovchinnikov, Y Bill, A Adrian, S Dolgov, O Shulga, S AF Kresin, V Wolf, S Ovchinnikov, Y Bill, A Adrian, S Dolgov, O Shulga, S TI Magnetic scattering, ''recovery'' of superconductivity and tunneling in the cuprates SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article; Proceedings Paper CT International Weak Superconductivity Symposium (WSS) CY AUG 04-07, 1996 CL SMOLENICE CASTLE, SLOVAK REPUBLIC ID LAYERED SUPERCONDUCTORS; SINGLE-CRYSTALS; THIN-FILMS; YBA2CU3O7-DELTA; FIELD; STATE AB High T-c cuprates contain various magnetic scatterers. Their presence affects many features of the materials, including tunneling density of states. Correlation between magnetic moments leads to a novel ''recovery'' effect, and, consequently, to an unusual temperature dependence of the Josephson current. C1 USN, RES LAB, WASHINGTON, DC 20375 USA. LD LANDAU THEORET PHYS INST, MOSCOW 11733, RUSSIA. PN LEBEDEV PHYS INST, MOSCOW 117924, RUSSIA. RUSSIAN ACAD SCI, INST SPECT, TROITSK 142092, RUSSIA. RP Kresin, V (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RI Wolf, Stuart/A-7513-2009 NR 48 TC 5 Z9 5 U1 0 U2 0 PU SPRINGER/PLENUM PUBLISHERS PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0022-2291 EI 1573-7357 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD FEB PY 1997 VL 106 IS 3-4 BP 159 EP 171 DI 10.1007/BF02399611 PG 13 WC Physics, Applied; Physics, Condensed Matter SC Physics GA WF905 UT WOS:A1997WF90500003 ER PT J AU StarLack, JM Roos, MS Wong, STS Schepkin, VD Budinger, TF AF StarLack, JM Roos, MS Wong, STS Schepkin, VD Budinger, TF TI Four-dimensional H-1 and Na-23 imaging using continuously oscillating gradients SO JOURNAL OF MAGNETIC RESONANCE LA English DT Article ID TIME-VARYING GRADIENTS; FIELD GRADIENTS; TRANSVERSE MAGNETIZATION; TRANSFORM NMR; MRI; SODIUM; RECONSTRUCTION; RELAXATION; SPECTROSCOPY; RESOLUTION AB A class of fast magnetic spectroscopic imaging methods using continuously oscillating gradients for four-dimensional (three spatial and one spectral) localization is introduced. Sampling may start immediately following the application of an RF excitation pulse, thus enabling measurement of spin density, chemical shift, and relaxation rates of short-T-2 species. For spatial localization, steady-state sinusoidal gradient waveforms are used to sample a ball in k space. The two types of trajectories presented include: (1) continuously oscillating gradients with continuously rotating direction used for steady-state free-precession imaging and (2) continuously oscillating gradients followed by a spoiler directed along discrete projections. Design criteria are given and spatial-spectral and spatial-temporal reconstruction methods are developed. Theoretical point-spread functions and signal-to-noise ratios are derived while considering T-2*, off-resonance effects, and RF excitation options. Experimental phantom, in vivo, and in vitro H-1 and Na-23 images collected at 2.35 T are presented. The H-1 images were acquired with isotropic spatial resolution ranging from 0.03 to 0.27 cm(3) and gradient-oscillation frequencies ranging from 600 to 700 Hz, thus allowing for the separation of water and lipid signals within a voxel. The Na-23 images, acquired with 500 and 800 Hz gradient waveforms and 0.70 cm(3) isotropic resolution, were resolved in the time domain, yielding spatially localized FIDs. (C) 1997 Academic Press. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,BERKELEY,CA 94720. RI Schepkin, Victor/A-1245-2007 NR 52 TC 9 Z9 9 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 1090-7807 J9 J MAGN RESON JI J. Magn. Reson. PD FEB PY 1997 VL 124 IS 2 BP 420 EP 438 DI 10.1006/jmre.1996.1052 PG 19 WC Biochemical Research Methods; Physics, Atomic, Molecular & Chemical; Spectroscopy SC Biochemistry & Molecular Biology; Physics; Spectroscopy GA WP821 UT WOS:A1997WP82100014 PM 9169223 ER PT J AU Vaidya, RU Zurek, AK Wolfenden, A Cantu, MW AF Vaidya, RU Zurek, AK Wolfenden, A Cantu, MW TI Strength and modulus of a molybdenum-coated Ti-25Al-10Nb-3V-1Mo intermetallic SO JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE LA English DT Article DE coatings; intermetallic compounds; modulus; strength; Ti-Al intermetallics ID ALUMINA; ALLOYS AB The three-point bend strength, Young's modulus, and vibrational damping of a plasma-sprayed molybdenum-coated Ti-25Al-10Nb-3V-1Mo intermetallic were measured, The bend strength of the intermetallic samples was significantly reduced as a result of the molybdenum coating, This decrease in the strength was attributed to cracks formed in the molybdenum coating during the plasma spraying process, Experimental measurements done using the piezoelectric ultrasonic composite technique (PUCOT) indicated that the modulus and vibrational damping of the coated samples were significantly higher than for the uncoated substrates, Thermal cycling of the molybdenum-coated intermetallic between 600 degrees C and room temperature revealed a saturation increase in the modulus with a corresponding decrease in the mechanical damping, This behavior was attributed to crack healing occurring in the molybdenum coating during the thermal cycling process. C1 TEXAS A&M UNIV,DEPT MECH ENGN,COLLEGE STN,TX 77843. RP Vaidya, RU (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 13 TC 4 Z9 5 U1 1 U2 2 PU ASM INTERNATIONAL PI MATERIALS PARK PA SUBSCRIPTIONS SPECIALIST CUSTOMER SERVICE, MATERIALS PARK, OH 44073-0002 SN 1059-9495 J9 J MATER ENG PERFORM JI J. Mater. Eng. Perform. PD FEB PY 1997 VL 6 IS 1 BP 46 EP 50 DI 10.1007/s11665-997-0031-2 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA WF874 UT WOS:A1997WF87400006 ER PT J AU Shield, JE Kramer, MJ AF Shield, JE Kramer, MJ TI Deformation-induced planar defects in Al-Cu-Fe quasicrystals SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID BURGERS VECTOR DETERMINATION; DECAGONAL QUASI-CRYSTAL; PLASTIC-DEFORMATION; ELECTRON-MICROSCOPY; DISLOCATIONS; ALLOY; TWINS; DIFFRACTION AB Planar defects were observed in a hot isostatically pressed Al-Cu-Fe alloy. The defects were determined to be perpendicular to the fivefold direction. They were also found to be regions where the quasiperiodicity in the five-fold direction was disrupted, resulting in a periodicity along this direction of 1.06 nm. The defects were stable up to approximately 750 degrees C. The defects were determined to be formed by the applied shear forces associated with the consolidation process. The displacement vector of the defects was determined to be in a twofold direction perpendicular to the periodic direction. C1 US DOE,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,AMES,IA 50011. RP Shield, JE (reprint author), UNIV UTAH,DEPT MAT SCI & ENGN,SALT LAKE CITY,UT 84112, USA. NR 24 TC 13 Z9 13 U1 1 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1997 VL 12 IS 2 BP 300 EP 303 DI 10.1557/JMR.1997.0039 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA WF468 UT WOS:A1997WF46800003 ER PT J AU AlShareef, HN Dimos, D Tuttle, BA Raymond, MV AF AlShareef, HN Dimos, D Tuttle, BA Raymond, MV TI Metallization schemes for dielectric thin film capacitors SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PT/TI; SILICON AB A detailed analysis of Pt/Ti, Pt/TiO2, and Pt/ZrO2 electrodes was carried out to develop a bottom electrode stack for sol-gel derived thin him capacitors. For the Pt/Ti stack, the choice of layer thickness and deposition temperature is found to affect adhesion to the SiO2/Si substrate as well as the extent of hillock formation and Pt-Ti interaction. By using elevated temperature deposition, Pt films close to 1 mu m in thickness can be produced with relatively good adhesion and morphological stability using Ti adhesion layers. In addition, Pt films grown on ZrO2 and TiO2 adhesion layers exhibit little morphological change and no degradation in sheet resistance after annealing at 650 degrees C. However, neither ZrO2 nor TiO2 are as effective as Ti metal in promoting Pt adhesion. Experiments aimed at establishing a correlation between hillock formation and capacitor yield revealed two important results. First, the behavior of Pt/Ti stacks during annealing in air is markedly different from their behavior during PZT him crystallization. Second, preannealing of the Pt/Ti in air prior to PZT film growth actually improves capacitor yield, even though hillock formation occurs during the preannealing treatment. Implications of these results regarding the role of hillocks in controlling capacitor yield are discussed. RP AlShareef, HN (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Alshareef, Husam Niman/A-2000-2015 OI Alshareef, Husam Niman/0000-0001-5029-2142 NR 11 TC 23 Z9 23 U1 0 U2 4 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1997 VL 12 IS 2 BP 347 EP 354 DI 10.1557/JMR.1997.0050 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA WF468 UT WOS:A1997WF46800014 ER PT J AU Stroud, RM Kelton, KF Misture, ST AF Stroud, RM Kelton, KF Misture, ST TI High temperature x-ray and calorimetric studies of phase transformations in quasicrystalline Ti-Zr-Ni alloys SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID QUASI-CRYSTALS; APPROXIMANT; SYSTEM AB We present the first high temperature x-ray diffraction (HTXRD) studies of in situ quasicrystal-crystal and crystal-crystal transformations in Ti-Zr-Ni alloys. Together with differential scanning calorimetry studies, these x-ray measurements indicate three separate paths for the Ti-Zr-Ni quasicrystal-crystal. transformation: single exothermic, single endothermic, or multiple endothermic. The mode of transformation depends on the alloy composition and the level of environmental oxygen. The crystalline products include the Ti2Ni, MgZn2 Laves, alpha-(Ti,Zr), and beta-(Ti,Zr) phases. In the absence of oxygen, the endothermic transformation of the quasicrystal demonstrates that it is the lowest free energy (stable) phase at the Ti53Zr27Ni20 composition. Oxygen stabilizes the Ti2Ni phase, eliminating both the quasicrystal and the MgZn2 Laves phase, at partial pressures as low as a few hundred ppm. C1 WASHINGTON UNIV,DEPT PHYS,ST LOUIS,MO 63130. OAK RIDGE NATL LAB,HIGH TEMP MAT LAB,OAK RIDGE,TN 37831. OI Stroud, Rhonda/0000-0001-5242-8015 NR 15 TC 30 Z9 31 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1997 VL 12 IS 2 BP 434 EP 438 DI 10.1557/JMR.1997.0064 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA WF468 UT WOS:A1997WF46800028 ER PT J AU Schwartz, RW Voigt, JA Tuttle, BA Payne, DA Reichert, TL DaSalla, RS AF Schwartz, RW Voigt, JA Tuttle, BA Payne, DA Reichert, TL DaSalla, RS TI Comments on the effects of solution precursor characteristics and thermal processing conditions on the crystallization behavior of sol-gel derived lead zirconate titanate thin films SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID PZT; MICROSTRUCTURE AB Lead zirconate titanate (PZT 40/60) thin films were fabricated on electroded silicon wafers using chemical solution deposition. Two different chelating agents, acetic acid and acetylacetone, were used in the synthesis of the precursor solutions. The microstructure of the acetylacetone-derived film was characterized by nucleation at the platinum electrode and a columnar growth morphology (similar to 100-200 nm lateral grain size). In contrast, the acetic acid-derived film was characterized by both columnar grains nucleated at the electrode, and larger (similar to 1 mu m) grains nucleated at the surface of the film. Using Fourier transform infrared (FTIR) diffuse reflectance spectroscopy, we also noted that the pyrolysis behavior of the films was dependent on the chelating agent employed. The acetylacetone-derived films, which displayed only one nucleation event, were also characterized by a higher pyrolysis temperature than the acetic acid-derived films. Previously, microstructural differences of this nature were attributed to variations in ''precursor structure.'' In this paper, we discuss an alternative mechanism for the observed microstructural variations in films prepared from different solution precursors. In the model proposed, we discuss how changes in film pyrolysis temperature result in a change in him crystallization temperature, and hence, a change in the effective driving force for crystallization. We show how the change in crystallization driving force is expected to impact the thin film microstructure due to the accompanying variations that occur in the barrier heights for interface (lower electrode) and surface nucleation A standard approach to nucleation in glasses is used as the basis of the proposed model. Finally, we also discuss how the model can be used to understand the observed effects of heating rate and thickness on the microstructure of solution-derived thin films. C1 UNIV ILLINOIS,DEPT MAT SCI & ENGN,SEITZ MAT RES LAB,URBANA,IL 61801. UNIV ILLINOIS,BECKMAN INST,URBANA,IL 61801. RP Schwartz, RW (reprint author), SANDIA NATL LABS,MAT & PROC SCI CTR,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 31 TC 106 Z9 107 U1 4 U2 28 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1997 VL 12 IS 2 BP 444 EP 456 DI 10.1557/JMR.1997.0066 PG 13 WC Materials Science, Multidisciplinary SC Materials Science GA WF468 UT WOS:A1997WF46800030 ER PT J AU Potter, BG Dimos, D Sinclair, MB AF Potter, BG Dimos, D Sinclair, MB TI Waveguide refractometry as a probe of thin film optical uniformity SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID WAVE-GUIDE REFRACTOMETRY AB Optical inhomogeneities through the thickness of a sol-gel-derived, spin-coated Pb(Zr,Ti)O-3 (PZT) thin film have been evaluated using prism-coupled waveguide refractometry. Unusual waveguide coupling angle behavior has been treated using a multilayer model to describe the optical characteristics of the film. Waveguide refractometry measurements, performed after incremental reductions in film thickness, were used to develop a consistent model for optical inhomogeneity through the film thickness. Specifically, a thin film layer model, consisting of alternating layers of high and low refractive index material, was found to accurately predict irregularities in transverse-electric (TE) mode coupling angles exhibited by the film. This layer structure has a spatial periodicity that is consistent with the positions of the upper film surface at intermediate firings during film synthesis. The correlation emphasizes the impact of the multistep thin-film deposition approach on the optical characteristics of the resulting thin film. RP Potter, BG (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 12 TC 2 Z9 2 U1 0 U2 1 PU MATERIALS RESEARCH SOCIETY PI WARRENDALE PA 506 KEYSTONE DR, WARRENDALE, PA 15086 SN 0884-2914 J9 J MATER RES JI J. Mater. Res. PD FEB PY 1997 VL 12 IS 2 BP 546 EP 551 DI 10.1557/JMR.1997.0078 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA WF468 UT WOS:A1997WF46800042 ER PT J AU Plucknett, KP Becher, PF Alexander, KB AF Plucknett, KP Becher, PF Alexander, KB TI In-situ SEM observation of the fracture behaviour of titanium carbide nickel aluminide composites SO JOURNAL OF MICROSCOPY-OXFORD LA English DT Article; Proceedings Paper CT Meeting of Microscopy of Composite Materials III CY APR 01-03, 1996 CL ST JOHNS COLLEGE, OXFORD, ENGLAND HO ST JOHNS COLLEGE DE composite; fracture resistance; in-situ testing; nickel aluminide; scanning electron microscopy; titanium carbide ID CEMENTED CARBIDES; BRITTLE MATERIALS; HARD METALS; TOUGHNESS; ALLOYS; CERMETS; NI3AL AB A range of experimental titanium carbide (TiC)/nickel aluminide (Ni3Al) composites have been developed. The Ni3Al content has been varied from 15 to 40 vol.%, for two different alloy compositions, The fracture behaviour of these composites was assessed in situ, within the chamber of a field emission gun scanning electron microscope, An applied moment double cantilever beam test geometry was employed, which allowed determination of the materials fracture resistance curve (or R-curve), while simultaneously monitoring crack-microstructure interactions. All of the tested materials exhibited a pronounced R-curve, with fracture resistance increasing with increasing crack length, up to a steady-state plateau value, The highest steady-state toughness values (up to 15 MPa m(-1/2)) were obtained for composites prepared with the highest Ni3Al binder content, In addition, these materials exhibited the highest strength and Weibull modulus. bl-situ examination of the fracture process demonstrated considerable crack wake bridging by ductile Ni3Al ligaments, with bridging zone length of >100 mu m often observed, The use of a displacement mapping technique has demonstrated that Ni3Al plastic deformation is highly localized around the crack, typically within one TiC grain width (i.e. approximate to 3-5 mu m) away from the crack. C1 OAK RIDGE NATL LAB,STRUCT CERAM GRP,OAK RIDGE,TN 37831. NR 31 TC 19 Z9 20 U1 1 U2 5 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0022-2720 J9 J MICROSC-OXFORD JI J. Microsc.-Oxf. PD FEB PY 1997 VL 185 BP 206 EP 216 DI 10.1046/j.1365-2818.1997.1640725.x PN 2 PG 11 WC Microscopy SC Microscopy GA WM657 UT WOS:A1997WM65700013 ER PT J AU Romano, SJ Corriveau, RA Schwarz, RI Berg, DK AF Romano, SJ Corriveau, RA Schwarz, RI Berg, DK TI Expression of the nicotinic receptor alpha 7 gene in tendon and periosteum during early development SO JOURNAL OF NEUROCHEMISTRY LA English DT Article DE nicotinic; receptor; alpha 7 mRNA; alpha 7 subunit; beta-bungarotoxin; tendon ID NEURONAL ACETYLCHOLINE-RECEPTORS; SMOOTH-MUSCLE CONTRACTION; SKELETAL-MUSCLE; MONOCLONAL-ANTIBODIES; LIGHT-CHAIN; CELL-LINES; CALCIUM; BUNGAROTOXIN; SUBUNIT; PHOSPHORYLATION AB One of the most abundant nicotinic acetylcholine receptors expressed in the central and peripheral nervous systems is a species that contains the alpha 7 gene product, binds alpha-bungarotoxin with high affinity, and has a high relative permeability to calcium. The alpha 7 gene is also expressed at low levels in embryonic muscle tissue, We show here that the alpha 7 gene is expressed in tendon fibroblasts and periosteal cells during development. In situ hybridizations identify alpha 7 transcripts in tissue sections containing embryonic tendon and periosteum. RNase protection experiments demonstrate alpha 7 mRNA in primary tendon cells grown in culture. Immunofluorescence with subunit-specific monoclonal antibodies reveals alpha 7 protein in embryonic tendon. Immunoprecipitation assays with the antibodies indicate that the alpha 7-containing species in tendon is capable of binding alpha-bungarotoxin and that a similar species can be identified at low levels on the surface of fibroblasts in culture. The results show that the alpha 7 gene product is expressed in a range of tissues, including cells thought to be nonexcitable. The distribution of alpha 7 expression early in development and the ability of alpha 7-containing receptors to elevate intracellular calcium suggest that the gene may influence a variety of calcium-dependent events during embryogenesis. C1 UNIV CALIF SAN DIEGO,DEPT BIOL,LA JOLLA,CA 92093. LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. FU NINDS NIH HHS [NS12601, NS35469] NR 57 TC 33 Z9 33 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 0022-3042 J9 J NEUROCHEM JI J. Neurochem. PD FEB PY 1997 VL 68 IS 2 BP 640 EP 648 PG 9 WC Biochemistry & Molecular Biology; Neurosciences SC Biochemistry & Molecular Biology; Neurosciences & Neurology GA WD079 UT WOS:A1997WD07900023 PM 9003051 ER PT J AU Douglass, DK Carstens, E AF Douglass, DK Carstens, E TI Responses of rat sacral spinal neurons to mechanical and noxious thermal stimulation of the tail SO JOURNAL OF NEUROPHYSIOLOGY LA English DT Article ID DORSAL HORN NEURONS; FLICK REFLEX; NOCICEPTIVE INFORMATION; DESCENDING INHIBITION; MORPHINE; MIDBRAIN; SUPPRESSION; CAT; CORD; MICROINJECTIONS AB In this study we investigated the receptive field properties, responses to mechanical and thermal stimuli, and sensitivity to systemic administration of pentobarbital sodium and morphine of single neurons recorded in the sacral spinal cords of pentobarbital-anesthetized rats. Fifty-three neurons responded to innocuous mechanical stimulation of the tail. Of 45 neurons that were additionally tested with noxious thermal stimulation, 62% responded and were classified as wide-dynamic-range or multireceptive neurons. Recording sites were located mainly in the middle layers of the S-2-S-4 dorsal horn. Mechanosensitive receptive fields on the tail varied widely in size (range 0.14-35 cm(2) mean 10.33 cm(2)) and form, and were in nearly all cases bilateral. Most neurons responded with a high-frequency discharge followed by a more slowly adapting response to pressure stimuli delivered with von Frey hairs. Responses (maximal frequency and total number of impulses) increased in a graded manner to pressure stimuli ranging from 1.2 to 447 g. For neurons responsive to noxious heating of the tail, responses increased in a linear manner over the range of 38-54 degrees C and often leveled off at higher temperatures. Of nine neurons tested with both graded von Frey and noxious heat stimuli, mean responses (maximal frequency and total number of impulses) evoked by the strongest pressure stimuli were larger than those evoked by the most intense heat stimuli, but the difference was not statistically significant. Responses to repeated 48 degrees C stimuli were significantly attenuated within 8 min after systemic administration of morphine (1 or 2 mg/kg ip), reaching maximal suppression (to 37.3%; N = 13) after 18 min, with recovery following systemic naloxone. After morphine (1 and 2 mg/kg ip), the slope of the population stimulus-response function for noxious heat was reduced (51.8%), and the threshold was increased (by 4 degrees C). Responses to noxious heat were significantly depressed (to a mean of 54%; N = 10) by supplemental administration of pentobarbital (mean 17 mg/kg over 5 min). On the basis of similarities between the present data and previous behavioral measures of tail flick stimulus-response functions and their modulation, it is suggested that some of the present neurons might function as interneurons in the tail flick reflex arc. C1 LAWRENCE LIVERMORE NATL LAB,SECT NEUROBIOL PHYSIOL & BEHAV,DAVIS,CA 95616. NR 43 TC 11 Z9 12 U1 0 U2 1 PU AMER PHYSIOLOGICAL SOC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 SN 0022-3077 J9 J NEUROPHYSIOL JI J. Neurophysiol. PD FEB PY 1997 VL 77 IS 2 BP 611 EP 620 PG 10 WC Neurosciences; Physiology SC Neurosciences & Neurology; Physiology GA WK036 UT WOS:A1997WK03600009 PM 9065834 ER PT J AU Alexander, DE AF Alexander, DE TI Defect production considerations for gamma ray irradiation of reactor pressure vessel steels SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID DISPLACEMENT CASCADES; MOLECULAR-DYNAMICS; DAMAGE; ALLOYS; METALS AB Motivated by the recent interest in gamma ray embrittlement of nuclear reactor pressure vessels (RPVs), calcultions were performed to evaluate aspects of defect production by gammas in iron and steel, in addition to determining displacement damage cross-sections, the atomic recoil energy dependence of gamma-induced defect production was described by integral recoil damage spectra, W(T), and their associated median recoil damage energies, T-1/2. These latter characterizations, should be particularly useful in evaluating the contribution of gamma ray generated defects to microstructural changes causing radiation embrittlement. The results for monoenergetic gammas, as well as for gamma rays with a spectrum of energies characteristic of a RPV, reveal T-1/2 values of < 100 eV, about three orders of magnitude smaller than for fast-neutrons, the radiation of primary concern in previous embrittlement studies. The relative contributions of various gamma interactions to defect production, as well as the role of light alloy element-induced secondary displacement mechanisms, are also considered. RP Alexander, DE (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 30 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD FEB PY 1997 VL 240 IS 3 BP 196 EP 204 DI 10.1016/S0022-3115(96)00713-1 PG 9 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WG576 UT WOS:A1997WG57600003 ER PT J AU Rest, J AF Rest, J TI A generalized model for radiation-induced amorphization and crystallization of U3Si and U3Si2 and recrystallization of UO2 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID HIGH-BURNUP UO2; FISSION-GAS RELEASE; MICROSTRUCTURAL CHANGE; FUEL PELLETS; SHOCK-WAVE; IRRADIATION AB A rate-theory model of radiation-induced amorphization and crystallization of U3Si during ion irradiation has been generalized to include U3Si2 and UO2. The generalized model has been applied to ion-irradiation and in-reactor experiments on U3Si and U3Si2 and provides an interpretation for the amorphization curve (dose required to amorphize the material as a function of temperature), for the ion-radiation-induced nanoscale polycrystallization of these materials at temperatures above the critical temperature for amorphization, as well as for the role of the small crystallites in retarding amorphization. An alternative mechanism for the evolution of recrystallization nuclei is described for a model of irradiation-induced recrystallization of UO2 wherein the stored energy in the UO2 is concentrated in a network of sinklike nuclei that diminish with dose due to interaction with radiation-produced defects. The sinklike nuclei are identified as cellular dislocation structures that evolve relatively early in the irradiation period. The complicated kinetics involved in the formation of a cellular dislocation network are approximated by the formation and growth of subgrains due to the interaction of shock waves produced by fission-induced damage to the UO2. RP Rest, J (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 29 TC 5 Z9 6 U1 4 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD FEB PY 1997 VL 240 IS 3 BP 205 EP 214 DI 10.1016/S0022-3115(96)00714-3 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WG576 UT WOS:A1997WG57600004 ER PT J AU Fuller, L Okoh, JM AF Fuller, L Okoh, JM TI Kinetics and mechanisms of the reaction of air with nuclear grade graphites: IG-110 SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID CARBON AB The work presented in this report is part of an ongoing effort in the microgravimetric evaluation of the intrinsic reaction parameters for air reactions with graphite over the temperature range of 450 to 750 degrees C. Earlier work in this laboratory addressed the oxidation/etching of H-451 graphite by oxygen and steam. This report addresses the air oxidation of the Japanese formulated material, IG-110. Fractal analysis showed that each cylinder was remarkably smooth, with an average value, D, the fractal dimension of 0.895. The activation energy, E(a), was determined to be 187.89 kJ/mol indicative of reactions occurring in the zone II kinetic regime and as a result of the porous nature of the cylinders. IG-110 is a microporous solid. The low initial reaction rate of 9.8 x 10(-5) at 0% burn-off and the high value (764.9) of Phi, the structural parameter confirm this. The maximum rate, 1.35 X 10(-3) g/m(2)s, was measured at 34% burn-off. Reactions appeared to proceed in three stages and transition between them was smooth over the temperature range investigated. Both E(a) and ln A did not vary with burn-off. The value of Delta S, the entropy of activation, was -41.4 eu, suggesting oxygen adsorption through an immobile transition state complex. Additional work is recommended to validate the predictions that will be made in relation to accident scenarios for reactors such as the modular high temperature gas-cooled reactor where fine grained graphites such as IG-110 could be used in structural applications. RP Fuller, L (reprint author), OAK RIDGE NATL LAB, DIV MET & CERAM, CARBON MAT TECHNOL GRP, OAK RIDGE, TN 37831 USA. NR 30 TC 29 Z9 33 U1 3 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD FEB PY 1997 VL 240 IS 3 BP 241 EP 250 DI 10.1016/S0022-3115(96)00462-X PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA WG576 UT WOS:A1997WG57600009 ER PT J AU Krishnamurthy, GT Swailem, FM Srivastava, SC Atkins, HL Simpson, LJ Walsh, TK Ahmann, FR Meinken, GE Shah, JH AF Krishnamurthy, GT Swailem, FM Srivastava, SC Atkins, HL Simpson, LJ Walsh, TK Ahmann, FR Meinken, GE Shah, JH TI Tin-117m(4+)DTPA: Pharmacokinetics and imaging characteristics in patients with metastatic bone pain SO JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE bone pain palliation; pharmacokinetics; tin-117m(4+)DTPA ID OSSEOUS METASTASES; INVIVO BEHAVIOR; BIODISTRIBUTION; CANCER; RADIOPHARMACEUTICALS; SAMARIUM-153-EDTMP; MANAGEMENT; PROSTATE; THERAPY; ANIMALS AB Biokinetics and imaging characteristics of Sn-117m(4+)DTPA have been studied in patients with metastatic bone pain. Methods: Seventeen patients with bone pain due to metastasis were given three dose levels: 180 mu Ci/kg (6.66 MBq/kg), 229 mu Ci/kg (8.37 MBq/kg) and 285 mu Ci/kg (10.55 MBq/kg) body weight. Periodic blood and daily urine samples were collected for 14 days to measure percent injected activity retained in blood and that excreted in urine. Simultaneous anterior and posterior view whole-body images were obtained under identical scan settings at 1, 3.5 and 24 hr and on Days 3 and 7 and between 4-6 and 8-10 wk postinjection. The total body retention was calculated using the geometric mean counts. Results: After intravenous injection, the total body clearance of Sn-117m(4+)DTPA shows two components: a soft-tissue component and a bone component. The soft-tissue component accounts for 22.4% of the dose and consists of four subcomponents with an average biologic clearance half-time of 1.45 days (range 0.1-3.2 days), The bone component accounting for the remaining 77.6% of the dose shows no biologic clearance. A mean 22.4% of the dose is excreted in urine in 14 days; 11.4% within 24 hr. The uptake pattern appears similar to that of Tc-99m-MDP. Peak uptake is observed in normal bone by 24 hr and metastatic lesions by 3-7 days. Pain palliation was observed with all three doses levels. Conclusion: Among the four potential bone pain palliation radionuclides, Sn-117m(4+)DTPA demonstrates the highest bone uptake and retention. Some biokinetic and radionuclidic features of Sn-117m(4+)DTPA are similar to other agents, but many features are different and unique and may make it an ideal bone pain palliation agent. Double-blind comparative studies are needed to determine its exact role in bone pain palliation. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV ARIZONA,SCH MED,TUCSON,AZ 85721. RP Krishnamurthy, GT (reprint author), VET ADM MED CTR,NUCL MED SERV 115,TUCSON,AZ 85723, USA. NR 25 TC 31 Z9 32 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD FEB PY 1997 VL 38 IS 2 BP 230 EP 237 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WF888 UT WOS:A1997WF88800024 PM 9025743 ER PT J AU Ribbons, KA Currie, MG Connor, JR Manning, PT Allen, PC Didier, P Ratterree, MS Clark, DA Miller, MJS AF Ribbons, KA Currie, MG Connor, JR Manning, PT Allen, PC Didier, P Ratterree, MS Clark, DA Miller, MJS TI The effect of inhibitors of inducible nitric oxide synthase on chronic colitis in the rhesus monkey SO JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS LA English DT Article ID GUINEA-PIG ILEITIS; ULCERATIVE-COLITIS; SELECTIVE-INHIBITION; LEUKOCYTE ADHESION; CROHNS-DISEASE; MODEL; INFLAMMATION; SUPEROXIDE; EXPRESSION; SECRETION AB GI inflammation is associated with an increase in nitric oxide production and expression of the inducible isoform of nitric oxide synthase (iNOS). Using a spontaneous model of chronic colonic inflammation in rhesus monkeys, which shares morphological and clinical features with ulcerative colitis, we assessed the therapeutic benefit of administration of iNOS inhibitors. Sixteen colitic rhesus monkeys underwent an endoscopy procedure before commencement of the trial, and biopsies from three sites of the colon and plasma were collected. Monkeys were randomly assigned to three treatment groups and were administered by oral bolus 60 mg/kg/day L-N-6-(1-Iminoethyl) lysine, 60 mg/kg/day aminoguanidine or a placebo (0.9% NaCl) twice daily. Monkeys were sacrificed after 10 days, colonic tissue from multiple sites was dissected and processed for histological and biochemical analysis. In rhesus colitis, diarrhea was characterized by a significant increase in fecal water content and daily fecal output. iNOS was localized immunohistochemically in plasma cells and neutrophils in the colonic mucosa and lamina propria, paralleled by enhanced iNOS gene expression determined by reverse-transcriptase polymerase chain reaction. Only L-N-6-(1-imineothyl) lysine administration resulted in a significant reduction in systemic nitric oxide production, and neither of the iNOS inhibitors significantly reduced the histological inflammatory score nor ameliorated diarrheal symptoms. From these findings, we conclude that in this chronic, spontaneous model of colonic inflammation, administering iNOS inhibitors with this treatment regimen did not provide any major therapeutic benefit. C1 LOUISIANA STATE UNIV,MED CTR,DEPT PEDIAT,NEW ORLEANS,LA 70112. MONSANTO CO,GD SEARLE,ST LOUIS,FRANCE. LAWRENCE LIVERMORE NATL LAB,CALIF REG PRIMATE RES CTR,DAVIS,CA 95616. TULANE REG PRIMATE RES CTR,COVINGTON,LA. FU NCRR NIH HHS [5P51-RR00164, 2P51-RR-AG00169]; PHS HHS [223-94-1100] NR 38 TC 50 Z9 50 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0022-3565 J9 J PHARMACOL EXP THER JI J. Pharmacol. Exp. Ther. PD FEB PY 1997 VL 280 IS 2 BP 1008 EP 1015 PG 8 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA WG580 UT WOS:A1997WG58000060 PM 9023318 ER EF