FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Dankov, SY Tishin, AM Pecharsky, VK Gschneider, KA AF Dankov, SY Tishin, AM Pecharsky, VK Gschneider, KA TI Experimental device for studying the magnetocaloric effect in pulse magnetic fields SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB A device for studying the magnetocaloric effect in pulsed magnetic fields up to 8 T is described. Data on magnetocaloric effect in gadolinium metal obtained by this technique was compared to that obtained by other experimental methods. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT MAT SCI & ENGN,AMES,IA 50011. RP Dankov, SY (reprint author), MOSCOW MV LOMONOSOV STATE UNIV,DEPT PHYS,MOSCOW 119899,RUSSIA. RI Tishin, Alexander/E-8705-2014 OI Tishin, Alexander/0000-0003-2252-7279 NR 9 TC 39 Z9 40 U1 2 U2 14 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 JUN PY 1997 VL 68 IS 6 BP 2432 EP 2437 DI 10.1063/1.1148057 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400030 ER PT J AU Behler, S Rose, MK Dunphy, JC Ogletree, DF Salmeron, M Chapelier, C AF Behler, S Rose, MK Dunphy, JC Ogletree, DF Salmeron, M Chapelier, C TI Scanning tunneling microscope with continuous flow cryostat sample cooling SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID VARIABLE-TEMPERATURE; ULTRAHIGH-VACUUM; PT(111) AB We have constructed an ultrahigh vacuum scanning tunneling microscope (STM) for operation in the temperature range 20-300 K. The design consists of a vibration isolated sample holder mounted on a continuous flow cryostat. By rotation and linear motion of the cryostat, the sample can be positioned in front of various surface preparation and analysis instruments contained in a single vacuum chamber. A lightweight beetle-type STM head is towered from the top onto the sample by a linear manipulator. To minimize helium convection in the cryostat, the entire vacuum system, including a liquid helium storage Dewar, can be tilted by a few degrees perpendicular to the cryostat axis, which improves the operation. The performance of the instrument is demonstrated by atomically resolved images of the Pd(111) surface and adsorbed CO molecules. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. CEA,DEPT RECH FONDAMENTALE MAT CONDENSEE,F-38054 GRENOBLE 9,FRANCE. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RI Ogletree, D Frank/D-9833-2016 OI Ogletree, D Frank/0000-0002-8159-0182 NR 22 TC 41 Z9 41 U1 3 U2 13 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 JUN PY 1997 VL 68 IS 6 BP 2479 EP 2485 DI 10.1063/1.1148172 PG 7 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400038 ER PT J AU Frantz, P Wolf, F Xiao, XD Chen, Y Bosch, S Salmeron, M AF Frantz, P Wolf, F Xiao, XD Chen, Y Bosch, S Salmeron, M TI Design of surface forces apparatus for tribology studies combined with nonlinear optical spectroscopy SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article ID LIQUIDS; FILMS AB We describe the design, calibration, and performance of surface forces apparatus with the capability of illumination of the contact interface for spectroscopic investigation using optical techniques. The apparatus can be placed in the path of a Nd-YAG laser for studies of the linear response or the second harmonic and sum-frequency generation from a material confined between the two surfaces. In addition to the standard fringes of equal chromatic order technique, which we have digitized for accurate and fast analysis, the distance of separation can be measured with a fiber-optic interferometer during spectroscopic measurements (2 Angstrom resolution and 10 ms response time). The sample approach is accomplished through application of a motor drive, piezoelectric actuator, or electromagnetic lever deflection for variable degrees of range, sensitivity, and response time. To demonstrate the operation of the instrument, the stepwise expulsion of discrete layers of octamethylcyclotetrasiloxane from the contact is shown. Lateral forces may also be studied by using piezoelectric bimorphs to induce and direct the motion of one surface. (C) 1997 American Institute of Physics. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV MAINZ,INST PHYS CHEM,D-55099 MAINZ,GERMANY. HONG KONG UNIV SCI & TECHNOL,DEPT PHYS,KOWLOON,HONG KONG. UNIV BARCELONA,DEPT FIS APLICADA & ELECT,E-08028 BARCELONA,SPAIN. NR 18 TC 18 Z9 18 U1 0 U2 8 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 JUN PY 1997 VL 68 IS 6 BP 2499 EP 2504 DI 10.1063/1.1148148 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400042 ER PT J AU Rosenberg, RA Ma, Q Farrell, W Keefe, M Mancini, DC AF Rosenberg, RA Ma, Q Farrell, W Keefe, M Mancini, DC TI X-ray welding of metal-matrix composites SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article AB We present the first results of use of the high power x-rays from an insertion device beamline at the Advanced Photon Source for welding. X-rays with energies between 3 and 200 keV and power densities greater than 10 000 W/cm(2) can penetrate deeply into most materials and thus can be used as volumetric heating sources. In this article we show results of bead-on-plate welds of a 3.3-mm-thick Al/Al2O3 metal-matrix composite and discuss results obtained for other materials. The potential of x-rays for welding is also discussed. (C) 1997 American Institute of Physics. RP Rosenberg, RA (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. RI Rosenberg, Richard/K-3442-2012 NR 6 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1997 VL 68 IS 6 BP 2550 EP 2553 DI 10.1063/1.1148159 PG 4 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400053 ER PT J AU Swenson, CA AF Swenson, CA TI Linear thermal expansivity (1.5-300 K) and heat capacity (1.2-90 K) of Stycast 2850FT (vol 68, pg 1312, 1997) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Correction, Addition C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. RP Swenson, CA (reprint author), IOWA STATE UNIV,AMES LAB,AMES,IA 50011, USA. NR 1 TC 1 Z9 1 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD JUN PY 1997 VL 68 IS 6 BP 2596 EP 2596 DI 10.1063/1.1148453 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA XF624 UT WOS:A1997XF62400062 ER PT J AU Burger, J Sanchez, J Gibbons, JW Gochfeld, M AF Burger, J Sanchez, J Gibbons, JW Gochfeld, M TI Risk perception, federal spending, and the Savannah River Site: Attitudes of hunters and fishermen SO RISK ANALYSIS LA English DT Article DE risk perception; hunting; fishing; environmental hazards; land use; recreation ID PERCEIVED RISK; NUCLEAR WASTE; TRUST AB This paper examines the attitudes of 285 hunters and fishermen from South Carolina about hunting and fishing, risk, environmental issues, and future land use of the Savannah River Site. We test the null hypothesis that there is no difference in hunting and fishing rates, attitudes toward the safety of fish and deer obtained from SRS, attitudes toward future land use at SRS, and perceptions of the severity of environmental problems as a function of how far respondents lived from the site. Respondents hunted or fished an average of over 40 days a year, and only half felt that the fish and deer from SRS were safe to eat. Willingness to expend federal funds was correlated with perceptions of the severity of the problem. Preferences for future land use at SRS fell into three categories: high (environmental research park, hunting, fishing, camping), medium (nuclear production, factories, preserve only), and low (nuclear waste storage, residential). There were no differences in hunting and fishing rates, ranking of the severity of environmental problems, and willingness to expend federal funds as a function of distance of residence from SRS, but attitudes toward future land use differed significantly as a function of location of residence. Those living close to SRS were more willing to have the site used for factories, residential, nuclear material production and to store nuclear wastes than those living farther from the site. Our data on recreational rates, attitudes toward future land use, and willingness to expend federal funds to solve environmental problems reiterate the importance of assessing stakeholder attitudes toward decisions regarding future land use at DOE sites. C1 ENVIRONM & OCCUPAT HLTH SCI INST,PISCATAWAY,NJ 08855. SAVANNAH RIVER ECOL LAB,AIKEN,SC 29802. UNIV MED & DENT NEW JERSEY,ROBERT WOOD JOHNSON MED SCH,PISCATAWAY,NJ 08854. RP Burger, J (reprint author), RUTGERS STATE UNIV,NELSON BIOL LAB,PISCATAWAY,NJ 08855, USA. NR 24 TC 39 Z9 39 U1 1 U2 3 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD JUN PY 1997 VL 17 IS 3 BP 313 EP 320 DI 10.1111/j.1539-6924.1997.tb00869.x PG 8 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA XK800 UT WOS:A1997XK80000005 PM 9232015 ER PT J AU Wheeler, TA Gawande, K Bespalko, S AF Wheeler, TA Gawande, K Bespalko, S TI Development of risk-based ranking measures of effectiveness for the United States Coast Guard's vessel inspection program SO RISK ANALYSIS LA English DT Article DE maritime safety; transportation risk; importance measures; measures of effectiveness; risk AB This paper describes the results of an analysis of the effectiveness of the U.S. Coast Guard's efforts to promote the safety of life and property at sea through its program to inspect large, ocean-going vessels. The effectiveness of specific U.S. Coast Guard vessel inspection activities was evaluated using risk-based metrics that linked categories of root causes of accidents to the particular inspection activities designed to reduce the risk of each root cause category. The results demonstrate a risk-based ranking of USCG inspection activities. These metrics, describes as measures of effectiveness (MOEs), yield insights regarding the most beneficial areas in which to concentrate inspection resources. Insights regarding quality of vessel casualty investigation data and database design as related to risk-based importance analysis are also discussed. The MOEs constructed in this study are specific to the USCG's Marine Inspection and Boarding Program, but the methodology of the study is based on sound theoretical principles that are probably applicable to a range of maritime safety activities. Hence the methodology applies equally to other important governmental regulatory programs and can be similarly used to measure their effectiveness and as an aid to decision-making. C1 UNIV NEW MEXICO,DEPT ECON,ALBUQUERQUE,NM 87131. RP Wheeler, TA (reprint author), SANDIA NATL LABS,DEPT 6626,POB 5800,MS 0720,ALBUQUERQUE,NM 87185, USA. NR 8 TC 1 Z9 2 U1 0 U2 2 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD JUN PY 1997 VL 17 IS 3 BP 333 EP 340 DI 10.1111/j.1539-6924.1997.tb00871.x PG 8 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA XK800 UT WOS:A1997XK80000007 ER PT J AU Williams, G AF Williams, G TI Oil in troubled waters: Perceptions, politics, and the battle over offshore drilling - Freudenburg,WR, Gramling,R SO RURAL SOCIOLOGY LA English DT Book Review RP Williams, G (reprint author), ARGONNE NATL LAB,ENVIRONM ASSESSMENT DIV,ARGONNE,IL 60439, USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU RURAL SOCIOLOGICAL SOC PI BELLINGHAM PA C/O RABEL J BURDGE, TREASURER, WESTERN WASHINGTON UNIV, DEPT SOCIOL ARNTZEN HALL R-510, BELLINGHAM, WA 98225-9081 SN 0036-0112 J9 RURAL SOCIOL JI Rural Sociol. PD SUM PY 1997 VL 62 IS 2 BP 283 EP 286 PG 4 WC Sociology SC Sociology GA XU656 UT WOS:A1997XU65600015 ER PT J AU Voelkl, E Allard, LF Nolan, TA Hill, D Lehmann, M AF Voelkl, E Allard, LF Nolan, TA Hill, D Lehmann, M TI Remote operation of electron microscopes SO SCANNING LA English DT Article DE digital access; computer control; remote control; video conferencing AB Due to the availability of fast local computer networks such as Ethernet and FDDI and fast point-to-point connections such as T1 and T3 links, the idea of telemicroscopy, including remote control of electron microscopes has gained momentum. Ellisman (1995), Fan et al. (1993), Parvin et al. (1995), and Zaluzec (1995) have discussed facets of systems which support such capabilities. In each of these reports the authors describe new stand-alone software packages that are required to run their systems. To make remote microscopy more universally available, we required the use of commercial software only and demanded scripting capabilities. By (1) expanding the de facto standard software DigitalMicrograph to include a complete set of SET and GET commands for microscope control, (2) using the software TimbuktuPro to provide remote control capabilities, and (3) using CUSeeMe and other video conferencing hardware and software for telecommunication, all our requirements were met. All three software packages together then provide remote microscope operation capabilities and an open system architecture (through the scripting language) for future design of automated procedures and telecommunication (Dodson et al. 1995, Gatan Inc., Voelkl et al. 1995a). The route for remote microscopy operation described herein allows microscope operation through local networks, the internet, and point-to-point connections with varying performance, and across Windows, Windows95, and Macintosh platforms. The expenses for the remote user are essentially defined by the price tags on establishing and maintaining the communication lines and the video conference tool of choice. This general approach has recently been demonstrated at the SuperComputing '95 conference in San Diego, Calif. C1 UNIV TUBINGEN,INST APPL PHYS,TUBINGEN,GERMANY. RP Voelkl, E (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 9 TC 8 Z9 8 U1 0 U2 0 PU FAMS INC PI MAHWAH PA BOX 832, MAHWAH, NJ 07430 SN 0161-0457 J9 SCANNING JI Scanning PD JUN PY 1997 VL 19 IS 4 BP 286 EP 291 PG 6 WC Instruments & Instrumentation; Microscopy SC Instruments & Instrumentation; Microscopy GA XF007 UT WOS:A1997XF00700008 ER PT J AU Robinson, CP Bailey, KC AF Robinson, CP Bailey, KC TI To zero or not to zero: A US perspective on nuclear disarmament SO SECURITY DIALOGUE LA English DT Article RP Robinson, CP (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 24 TC 1 Z9 1 U1 0 U2 0 PU SAGE PUBLICATIONS LTD PI LONDON PA 6 BONHILL STREET, LONDON, ENGLAND EC2A 4PU SN 0967-0106 J9 SECUR DIALOGUE JI Secur. Dialogue PD JUN PY 1997 VL 28 IS 2 BP 149 EP 158 DI 10.1177/0967010697028002003 PG 10 WC International Relations SC International Relations GA XE609 UT WOS:A1997XE60900003 ER PT J AU Heuze, FE Ueng, TS Hutchings, LJ Jarpe, SP Kasameyer, PW AF Heuze, FE Ueng, TS Hutchings, LJ Jarpe, SP Kasameyer, PW TI A coupled seismic-geotechnical approach to site-specific strong motion SO SOIL DYNAMICS AND EARTHQUAKE ENGINEERING LA English DT Article DE earthquakes; strong-motion; empirical Green's functions; dynamic effective stress analysis; bridges ID EMPIRICAL GREENS-FUNCTIONS; GROUND MOTION; EARTHQUAKE AB At Lawrence Livermore National Laboratory (LLNL) we have developed a new approach to provide estimates of incident strong ground-motion time-histories at bedrock, which are specific to a site. The estimates involve the recording of small earthquakes at the site, both at bedrock and at the surface, from specific faults in the region. The method also involves the definition of rupture scenarios for those faults. The estimates are obtained for earthquakes of specified moment magnitude (energy release). The new approach is a coupled seismic-geotechnical method. Besides its advantage of giving site-specific time-histories, this approach has the added benefit of providing an optimized definition of the dynamic geotechnical site properties which will be used to calculate shear wave propagation in the soils, from the estimated bedrock motions. This method is intended to replace state-of-practice approaches in which the site motion estimation may involve data from distant locations and faults having nothing to do with the specific site. The procedure is demonstrated at the Painter Street bridge site in Rio Dell, CA, for which we provide a range of surface motions corresponding to an earthquake of magnitude 7 on the subducting plate underlying this region. These calculated motions bracket the records of the Petrolia event (M = 7) measured near the site. Published by Elsevier Science Ltd. RP Heuze, FE (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 41 TC 6 Z9 6 U1 0 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0267-7261 J9 SOIL DYN EARTHQ ENG JI Soil Dyn. Earthq. Eng. PD JUN PY 1997 VL 16 IS 4 BP 259 EP 272 DI 10.1016/S0267-7261(97)00001-8 PG 14 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA XC370 UT WOS:A1997XC37000002 ER PT J AU Dymond, C Kutscher, C AF Dymond, C Kutscher, C TI Development of a flow distribution and design model for transpired solar collectors SO SOLAR ENERGY LA English DT Article AB Unglazed, transpired solar collectors offer a low-cost, high-efficiency means for preheating outside air for ventilation and crop drying applications. Although large building wall applications for these collectors have generally performed well in the field, many have exhibited poor flow distribution which can prevent maximum efficiency from being achieved. The objective of this work was to develop a computer model which would run quickly on a personal computer and allow designers of transpired collectors to easily adjust geometric parameters to achieve reasonable flow uniformities and to determine efficiencies. This paper describes how this model was developed and includes results from model runs. In order to allow the model to run quickly on the PC, pipe network methods were used to develop a set of simultaneous equations in the unknown flow rates. Previous research results on heat exchange effectiveness, pressure drop, and wind heat loss were incorporated. (C) 1997 Elsevier Science Ltd. C1 AMER SAMOA TERR ENEGY OFF,PAGO PAGO,AS 96799. NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 14 TC 36 Z9 36 U1 0 U2 10 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-092X J9 SOL ENERGY JI Sol. Energy PD JUN PY 1997 VL 60 IS 5 BP 291 EP 300 DI 10.1016/S0038-092X(96)00157-0 PG 10 WC Energy & Fuels SC Energy & Fuels GA XK310 UT WOS:A1997XK31000006 ER PT J AU Yi, KS Quinn, JJ AF Yi, KS Quinn, JJ TI Fermi liquid shell model descriptions of composite fermions SO SOLID STATE COMMUNICATIONS LA English DT Article DE fractional quantum Hall effect ID INCOMPRESSIBLE QUANTUM FLUID; HALL; EXCITATIONS; HIERARCHY AB Systems containing a small number of quasiparticles of a Laughlin v = 1/m state can be described in terms of composite Fermions carrying either 2p(-) or 2p(+) flux quanta, where 2p(+/-) = m +/- 1. The Fermi liquid shell model is applied to these two descriptions for a system of the six electrons on a spherical magnetic surface, and predictions for the low energy spectra are compared with one another and with exact numerical results. (C) 1997 Published by Elsevier Science Ltd. C1 PUSAN NATL UNIV,PUSAN 609735,SOUTH KOREA. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Yi, KS (reprint author), UNIV TENNESSEE,KNOXVILLE,TN 37996, 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 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD JUN PY 1997 VL 102 IS 11 BP 775 EP 777 DI 10.1016/S0038-1098(97)00105-1 PG 3 WC Physics, Condensed Matter SC Physics GA XA614 UT WOS:A1997XA61400001 ER PT J AU Lee, JW Abernathy, CR Pearton, SJ Ren, F Shul, RJ Constantine, C Barratt, C AF Lee, JW Abernathy, CR Pearton, SJ Ren, F Shul, RJ Constantine, C Barratt, C TI Effects of H-2 plasma exposure on GaAs/AlGaAs heterojunction bipolar transistors SO SOLID-STATE ELECTRONICS LA English DT Article ID MOMBE; HBTS; ETCH; GAAS AB GaAs/AlGaAs heterojunction bipolar transistors with highly C-doped base layers (p = 7 x 10(19) cm(-3)) were exposed to Inductively Coupled Plasma (ICP) or Electron Cyclotron Resonance (ECR) H-2 plasmas at different source powers and rf chuck powers to simulate the effects of ion damage and hydrogen passivation during CH4/H-2 dry etch fabrication of the devices. The HBT d.c. current gain decreases with increasing rf chuck powers in both types of reactor because of increased ion damage. This gain is less affected at high ICP source power because of the suppression of cathode de self-bias and hence ion energy, but is more degraded at high ECR source power since cathode d.c. self-bias increases under these conditions. The ICP tool is preferred for CH4/H-2 dry etching of HBTs because there is less disruption of the electrical properties of these devices. (C) 1997 Elsevier Science Ltd. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. PLASMA THERM IP,ST PETERSBURG,FL 33716. RP Lee, JW (reprint author), UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611, USA. RI Schaff, William/B-5839-2009 NR 24 TC 19 Z9 19 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0038-1101 J9 SOLID STATE ELECTRON JI Solid-State Electron. PD JUN PY 1997 VL 41 IS 6 BP 829 EP 833 DI 10.1016/S0038-1101(97)00026-9 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA XJ044 UT WOS:A1997XJ04400004 ER PT J AU deSouza, S Visco, SJ DeJonghe, LC AF deSouza, S Visco, SJ DeJonghe, LC TI Thin-film solid oxide fuel cell with high performance at low-temperature SO SOLID STATE IONICS LA English DT Article DE solid oxide fuel cell; thin films; high power density AB A planar thin-film solid oxide fuel cell (SOFC) was developed at the Lawrence Berkeley National Laboratory - Materials Science Division. The thin-film SOFC is fabricated with an inexpensive and scalable technique involving colloidal deposition of YSZ on porous NiO-YSZ substrates, yielding SOFCs capable of high power density at an operating temperature of 800 degrees C. The thickness of the YSZ film deposited onto the porous substrates is approximately 10 mu m after sintering. Ni-YSZ/YSZ/LSM cells built with this technique have exhibited theoretical open circuit voltages (OCVs), high diffusion limited current densities and high power density. The cells have been tested for long periods of time (over 700 h) and have been thermally cycled from 600-800 degrees C while demonstrating excellent stability over time. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NR 6 TC 319 Z9 323 U1 17 U2 108 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2738 J9 SOLID STATE IONICS JI Solid State Ion. PD JUN PY 1997 VL 98 IS 1-2 BP 57 EP 61 DI 10.1016/S0167-2738(96)00525-5 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XH789 UT WOS:A1997XH78900008 ER PT J AU Contolini, RJ Mayer, ST Graff, RT Tarte, L Bernhardt, AF AF Contolini, RJ Mayer, ST Graff, RT Tarte, L Bernhardt, AF TI Electrochemical planarization of ULSI copper SO SOLID STATE TECHNOLOGY LA English DT Article AB Electrochemical planarization (ECP) of copper has been demonstrated on ULSI damascene features. The basic process involves two stages: cathodic plating into vias and trenches, and anodic electropolishing down to a seed layer. Resulting metal structures are void-free. A semiautomatic aqueous processing system, based upon an easily controlled chemistry, has achieved reasonable uniformities. This simple process could be much less expensive than alternatives for less than or equal to 0.25-mu m interconnects. C1 LAWRENCE LIVERMORE NATL LAB,ELECTROCHEM TECHNOL GRP,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,DEPT ELECT ENGN,MICROELECT DIV,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,CTR MICROELECT & OPTOELECT,LIVERMORE,CA 94550. RP Contolini, RJ (reprint author), LAWRENCE LIVERMORE NATL LAB,MICROELECT PROGRAM,POB 808,LIVERMORE,CA 94550, USA. NR 12 TC 10 Z9 10 U1 1 U2 2 PU PENNWELL PUBL CO SOLID STATE TECHNOLOGY OFFICE PI NASHUA PA TEN TARA BLVD 5TH FLOOR, NASHUA, NH 03062-2801 SN 0038-111X J9 SOLID STATE TECHNOL JI Solid State Technol. PD JUN PY 1997 VL 40 IS 6 BP 155 EP & PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA XD016 UT WOS:A1997XD01600027 ER PT J AU Fadley, CS VanHove, MA Hussain, Z Kaduwela, AP Couch, RE Kim, YJ Len, PM Palomares, J Ryce, S Ruebush, S Tober, ED Wang, Z Ynzunza, RX Daimon, H Galloway, H Salmeron, MB Schattke, W AF Fadley, CS VanHove, MA Hussain, Z Kaduwela, AP Couch, RE Kim, YJ Len, PM Palomares, J Ryce, S Ruebush, S Tober, ED Wang, Z Ynzunza, RX Daimon, H Galloway, H Salmeron, MB Schattke, W TI Photoelectron diffraction: Space, time, and spin dependence of surface structures SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT Winter Workshop on Electron Diffraction and Imaging at Surfaces CY JAN 03-06, 1996 CL SCOTTSDALE, AZ SP Int Union Crystallog, US DOE, Arizona State Univ, Eiko Engn Ltd, JEOL Inc, Matsushita Res Inst, Tokyo, Inc, Nagoya Ind Sci Res Inst, NEC Corp, Japan, Toshiba Corp, Toyota Motor Corp, Lawrence Berkeley Natl Lab ID X-RAY-PHOTOELECTRON; ELECTRON-EMISSION HOLOGRAPHY; CORE-LEVEL PHOTOEMISSION; ANGULAR-RESOLVED PHOTOEMISSION; METAL-METAL INTERFACES; RANGE-MAGNETIC-ORDER; AUGER-ELECTRON; MULTIPLE-SCATTERING; AZIMUTHAL ANISOTROPY; CIRCULAR-DICHROISM AB The current status of photoelectron-diffraction studies of surface structures is briefly reviewed, and several recent developments and proposals for future areas of application are then discussed. The application of full-solid-angle diffraction data, together with simultaneous characterization by low-energy electron-diffraction and scanning-tunneling microscopy, to epitaxial growth is considered. Several new avenues that are being opened up by third-generation synchrotron-radiation sources are also considered. These include photoelectron diffraction from surface and interface atoms, the possibility of time-resolved measurements, and circular dichroism in photoelectron angular distributions. The addition of spin to the photoelectron-diffraction measurement is also considered, and can be achieved either through core-level multiplet splittings or by circular-polarized excitation of spin-orbit-split levels. This last development should make it possible to study short-range magnetic order, perhaps even in a holographic fashion. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV HAWAII,DEPT CHEM,HONOLULU,HI 96822. OSAKA UNIV,DEPT MAT PHYS,TOYONAKA,OSAKA 560,JAPAN. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. CHRISTIAN ALBRECHTS UNIV KIEL,INST THEORET PHYS,D-24118 KIEL,GERMANY. RP Fadley, CS (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616, USA. RI Van Hove, Michel/A-9862-2008; Palomares, Francisco Javier/C-4605-2011; OI Van Hove, Michel/0000-0002-8898-6921; Palomares, Francisco Javier/0000-0002-4768-2219; Kaduwela, Ajith/0000-0002-7236-2698 NR 131 TC 24 Z9 25 U1 1 U2 6 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD JUN PY 1997 VL 4 IS 3 BP 421 EP 440 DI 10.1142/S0218625X97000420 PG 20 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XV337 UT WOS:A1997XV33700002 ER PT J AU VanHove, MA AF VanHove, MA TI Determination of complex surface structures with LEED SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT Winter Workshop on Electron Diffraction and Imaging at Surfaces CY JAN 03-06, 1996 CL SCOTTSDALE, AZ SP Int Union Crystallog, US DOE, Arizona State Univ, Eiko Engn Ltd, JEOL Inc, Matsushita Res Inst, Tokyo, Inc, Nagoya Ind Sci Res Inst, NEC Corp, Japan, Toshiba Corp, Toyota Motor Corp, Lawrence Berkeley Natl Lab ID ENERGY-ELECTRON-DIFFRACTION; TENSOR LEED; CRYSTALLOGRAPHY; OPTIMIZATION; APPROXIMATION; ETHYLIDYNE; HOLOGRAPHY; COVERAGE; CU(001) AB The evolution of the complexity of structural determination attainable with LEED is reviewed. Considerable progress in methodologies and computers has enabled structures as complex as Cu(100) + (4 x 4)-10Li to be solved in terms of 18 fit parameters. The Si(111)-(7 x 7) structure could now be refined in terms of 100-or-so fit parameters, if a large-enough experimental dataset were available. Big challenges remain: finding a direct or quick way to identify the one qualitatively correct structure; and, to a lesser degree, providing the required size of the experimental dataset. RP VanHove, MA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720, USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 46 TC 10 Z9 10 U1 0 U2 8 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD JUN PY 1997 VL 4 IS 3 BP 479 EP 487 DI 10.1142/S0218625X97000468 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XV337 UT WOS:A1997XV33700006 ER PT J AU VanHove, MA AF VanHove, MA TI Preface SO SURFACE REVIEW AND LETTERS LA English DT Editorial Material RP VanHove, MA (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 0 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 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD JUN PY 1997 VL 4 IS 3 BP R3 EP R3 DI 10.1142/S0218625X97000419 PG 1 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XV337 UT WOS:A1997XV33700001 ER PT J AU Jaffe, JE Zapol, P AF Jaffe, JE Zapol, P TI Atomic relaxation of the BeO (10(1)over-bar0) surface SO SURFACE SCIENCE LA English DT Letter DE ab initio quantum chemical methods and calculations; beryllium oxide; surface relaxation and reconstruction ID AB-INITIO; ZNO; IONICITY AB The atomic relaxation of the nonpolar <(10(1)over bar 0)> surface of BeO has been calculated by minimizing the surface energy within the framework of the ab initio Hartree-Fock method. A six-layer two-dimensionally periodic slab model was used, permitting a full symmetry-conserving relaxation of the two outer layers. The Be-O surface bands show a small rotation angle of about 4 degrees accompanied by a large (about 10%) reduction in surface bond length. Significant contraction of backbonds and a small rotation of second layer bonds are also found. The relaxed BeO <(10(1)over bar 0)> surface is thus predicted to be similar to the ZnO <(10(1)over bar 0)> surface but different from the corresponding surfaces of all other II-VI compounds. Various explanations for this difference are discussed, and evidence from a bond population analysis is presented which suggests that this behavior can be described in terms of partial double bond character in the surface bonds. Since multiple bonding is related to small atomic radii, it would follow that the small radius of the oxygen atom is the ultimate cause of the type of surface relaxation we predict. (C) 1997 Elsevier Science B.V. C1 MICHIGAN TECHNOL UNIV, DEPT PHYS, HOUGHTON, MI 49931 USA. RP Jaffe, JE (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. RI Zapol, Peter/G-1810-2012 OI Zapol, Peter/0000-0003-0570-9169 NR 16 TC 4 Z9 4 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 JUN 1 PY 1997 VL 381 IS 1 BP L563 EP L567 DI 10.1016/S0039-6028(97)00059-9 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XH339 UT WOS:A1997XH33900006 ER PT J AU Mittler, J AF Mittler, J TI What happens when predators do not completely consume their prey? SO THEORETICAL POPULATION BIOLOGY LA English DT Article ID 2 COMPETITORS; FUNCTIONAL-RESPONSE; FORAGING BEHAVIOR; ONE RESOURCE; PATCH USE; COEXISTENCE; ECOLOGY; ENVIRONMENT; POPULATION; COMMUNITY AB A mathematical model is presented for the dynamics of predator-prey interactions wheat predators do not consume prey (or clumps of prey) In their entirety. Using a combination of analytical and numerical methods, demonstrate that predator-mediated changes in like distribution of intact and partially consumed prey can affect the outcome of competition between predators in unexpected ways. In some cases, two predators can coexist on a single prey species owing to tradeoffs between the ability to consume prey completely and other competitive abilities. In other cases, predators exhibit frequency-dependent dynamics in which the first predator to occupy the habitat can prevent the other from invading. Conditions for stable coexistence usually expand if the larger predator scatters uneaten prey pares, if prey renewal includes both small and large items, or if the predator with the smaller retrieval capacity is poor aa catching intact prey relative to the other predator. (C) 1997 Academic Press. C1 UNIV CALIF IRVINE,IRVINE,CA 92717. EMORY UNIV,ATLANTA,GA 30322. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. FU NIGMS NIH HHS [GM33782, GM16335] NR 40 TC 12 Z9 12 U1 0 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0040-5809 J9 THEOR POPUL BIOL JI Theor. Popul. Biol. PD JUN PY 1997 VL 51 IS 3 BP 238 EP 251 DI 10.1006/tpbi.1997.1305 PG 14 WC Ecology; Evolutionary Biology; Genetics & Heredity SC Environmental Sciences & Ecology; Evolutionary Biology; Genetics & Heredity GA XN646 UT WOS:A1997XN64600006 PM 9245778 ER PT J AU Malhotra, SG Rek, ZU Yalisove, SM Bilello, JC AF Malhotra, SG Rek, ZU Yalisove, SM Bilello, JC TI Analysis of thin film stress measurement techniques SO THIN SOLID FILMS LA English DT Article DE depth profiling; molybdenum; stress; X-ray diffraction ID X-RAY-DIFFRACTION; INTERNAL-STRESSES; MO FILMS; MECHANICAL-PROPERTIES; INTRINSIC STRESS; MOLYBDENUM FILMS; RESIDUAL-STRESS; MICROSTRUCTURE; RESISTIVITY; TOPOGRAPHY AB Residual stresses in several magnetron sputtered Mo thin films, with thicknesses from 100 nm to 1.60 mu m, were determined using double-crystal diffraction topography (DCDT), sin(2) psi, and the high-resolution X-ray diffraction technique (HRXRD). The Mo films had a range of microstructures that included random and polycrystalline, textured out-of-pIane, and textured in-plane. When the average biaxial stresses over the entire film thickness were determined for the films using the aforementioned techniques, the results were comparable in magnitude. However, the stresses determined with the substrate curvature technique, DCDT, were consistently smaller than those obtained with the sin(2) psi and HRXRD techniques. The difference may arise for several reasons. For example, the HRXRD and sin(2) psi measurements of a textured film may not be indicative of the mean film stress, and thus may differ from the curvature measurement. Also, substrate curvature techniques measure extrinsic stresses, or stresses that arise solely from the presence of the substrate. The techniques which analyze the film directly, such as sin(2) psi, and HRXRD, measure the extrinsic stresses and the intrinsic stresses that arise from defects or morphology changes within the film. The additional information that can be obtained from the depth-sensitive HRXRD technique concerning stress variations within thin films was also highlighted. (C) 1997 Elsevier Science S.A. C1 UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94395. NR 49 TC 36 Z9 38 U1 2 U2 19 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUN 1 PY 1997 VL 301 IS 1-2 BP 45 EP 54 DI 10.1016/S0040-6090(96)09569-7 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XJ084 UT WOS:A1997XJ08400008 ER PT J AU Malhotra, SG Rek, Z Yalisove, SM Bilello, JC AF Malhotra, SG Rek, Z Yalisove, SM Bilello, JC TI Depth-sensitive strain analysis of a W-Ta-W trilayer SO THIN SOLID FILMS LA English DT Article DE depth profiling; multilayers; X-ray diffraction ID X-RAY-DIFFRACTION; THIN-FILMS; STRESSES; MICROSTRUCTURE AB The high-resolution X-ray diffraction technique was used to determine the entire strain tensor as a function of X-ray penetration depth in a 400 nm W-Ta-W trilayer, which consisted of 150 nm W, 100 nm Ta, and 150 nm W. The strain tensor was calculated in a laboratory reference frame to determine the variation of in-plane strains, epsilon(xx) and epsilon(yy), and the normal strain epsilon(zz), as a function of X-ray penetration depth. Two different methods were then used to determine the strains epsilon(xx), epsilon(yy), and epsilon(zz) in each layer of trilayer. The first approach was based on diffraction peak subtraction, and the second on a linear elastic model. Both indicated that the strain states in the W layers were the same, and that the strains epsilon(xx) and epsilon(yy) in the W and Ta layer were the same magnitude. The difference between the Ta and W arose with the normal strain epsilon(zz), and was due to a Poisson contraction effect. The average residual stresses in the trilayer were determined with the HRXRD data, and also with sin(2) psi and a substrate curvature technique, double-crystal diffraction topography. All three techniques indicated that the average biaxial stress in the trilayer was ca. 1.0 GPa. C1 STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94395. UNIV MICHIGAN,DEPT MAT SCI & ENGN,ANN ARBOR,MI 48109. RP Malhotra, SG (reprint author), IBM CORP,SEMICOND RES & DEV CTR,1580 ROUTE 52,HOPEWELL JCT,NY 12533, USA. NR 29 TC 5 Z9 5 U1 0 U2 3 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD JUN 1 PY 1997 VL 301 IS 1-2 BP 55 EP 61 DI 10.1016/S0040-6090(96)09570-3 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XJ084 UT WOS:A1997XJ08400009 ER PT J AU Stauber, AJ Bull, RJ AF Stauber, AJ Bull, RJ TI Differences in phenotype and cell replicative behavior of hepatic tumors induced by dichloroacetate (DCA) and trichloroacetate (TCA) SO TOXICOLOGY AND APPLIED PHARMACOLOGY LA English DT Article ID GLUTATHIONE-S-TRANSFERASE; MALE B6C3F1 MOUSE; PEROXISOME PROLIFERATION; RAS PROTOONCOGENE; DRINKING-WATER; STRAND BREAKS; LIVER-TUMORS; ACID; MICE; INDUCTION AB Dichloroacetate (DCA) and trichloroacetate (TCA) are two hepatocarcinogenic by-products of water chlorination. To compare the effects of DCA and TCA on cell replication in the nodules and tumors they induce, male B6C3F1 mice were administered 2.0 g/L DCA or TCA in their drinking water for 38 or 50 weeks, respectively. The pretreated mice were then given water containing 0, 0.02, 0.5, 1.0, or 2.0 g/L DCA or TCA for two additional weeks to determine whether cell proliferation in the normal liver or tumors that had been induced by DCA or TCA was dependent on continued treatment. Prior to sacrifice the mice were subcutaneously implanted with mini-osmotic pumps to label DNA in dividing cells with 5-bromo-2'-deoxyuridine (BrdU). Serial sections of nodules/tumors and normal liver were stained immunohistochemically for BrdU, the oncoproteins c-Jun and c-Fos, and hematoxylin and eosin (H & E); or with Periodic acid-Schiff (PAS) stain, BrdU, and H & E, respectively. DCA and TCA transiently stimulated the division of normal hepatocytes relative to rates observed in the livers of control mice. However, at 40 and 52 weeks of treatment, replication of normal hepatocytes was substantially inhibited by DCA and TCA, respectively. Cell division within DCA-induced lesions that were identified macroscopically was significantly higher with increasing dose of DCA administered in the last 2 weeks of the experiment, DCA-induced lesions were found to display immunoreactivity to anti-c-Jun and anti-c-Fos antibodies, were predominantly basophilic, and contained very little glycogen relative to surrounding hepatocytes. In contrast, rates of cell division within TCA-induced altered hepatic foci and tumors were very high and appeared to be independent of continued treatment. TCA-induced lesions did not display immunoreactivity to either c-Jun or c-Fos antibodies. Results from this study suggest that the mechanisms by which DCA and TCA induce hepatocarcinogenesis in the male B6C3F1 mouse differ. (C) 1997 Academic Press. C1 WASHINGTON STATE UNIV, PHARMACOL TOXICOL GRAD PROGRAM, PULLMAN, WA 99164 USA. RP Stauber, AJ (reprint author), PACIFIC NW LAB, MOL BIOSCI DEPT, POB 999,MSIN-P7-56, RICHLAND, WA 99352 USA. FU NIEHS NIH HHS [R01-ESO4648] NR 45 TC 35 Z9 35 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0041-008X J9 TOXICOL APPL PHARM JI Toxicol. Appl. Pharmacol. PD JUN PY 1997 VL 144 IS 2 BP 235 EP 246 DI 10.1006/taap.1997.8159 PG 12 WC Pharmacology & Pharmacy; Toxicology SC Pharmacology & Pharmacy; Toxicology GA XF149 UT WOS:A1997XF14900004 PM 9194407 ER PT J AU Zhang, DX AF Zhang, DX TI Conditional stochastic analysis for multiphase transport in randomly heterogeneous, variably saturated media SO TRANSPORT IN POROUS MEDIA LA English DT Article DE stochastic analysis; conditional probability; multiphase transport; heterogeneous porous media ID SUBSURFACE SOLUTE TRANSPORT; NONAQUEOUS PHASE LIQUIDS; EXACT NONLOCAL FORMALISM; POROUS-MEDIA; ORGANIC-COMPOUNDS; GROUNDWATER CONTAMINATION; UNSATURATED ZONE; HYDRAULIC-PROPERTIES; SPATIAL VARIABILITY; WEAK APPROXIMATION AB Groundwater contamination of organics has recently become a problem of growing concern over the resulting health and environmental problems. In general, the multiphase system of nonaqueous phase liquid (NAPL), water and air has to be studied in order to realistically describe the movement of such materials in the subsurface. Numerous models have been developed to study multiphase flow and/or multispecies transport in porous media. However, using models to study the influence of medium heterogeneity on such flow and transport is only a recent event. It has been demonstrated for single-phase flow and transport in saturated and unsaturated media that the study of medium heterogeneity is amenable to stochastic analysis. In this paper, we extend our Eulerian-Lagrangian stochastic theory for single-phase transport to the problem of multi phase-multispecies transport in randomly heterogeneous media under the conditions that the flow is steady-state and the phases are in local chemical equilibrium. We present theoretical expressions to describe the first two conditional moments of the random concentration of any species in any phase. Though they reveal some of the fundamental properties and help gaining insight into the nature of the problem, these expressions cannot be evaluated without either high resolution Monte Carlo simulation or approximation (closure). Therefore, we propose two sets of workable approximations, one being a weak approximation and the other being a linearized pseudo-Fickian approximation. The former yields a nonlinear integro-differential equation for the first conditional moment and the latter yields a linear differential equation. Then the second moments can be computed from explicit expressions from either the weak or pseudo-Fickian approximation. RP Zhang, DX (reprint author), LOS ALAMOS NATL LAB,GEOANAL GRP,MS C400,POB 1663,LOS ALAMOS,NM 87545, USA. RI Zhang, Dongxiao/D-5289-2009 OI Zhang, Dongxiao/0000-0001-6930-5994 NR 54 TC 1 Z9 1 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0169-3913 J9 TRANSPORT POROUS MED JI Transp. Porous Media PD JUN PY 1997 VL 27 IS 3 BP 265 EP 287 DI 10.1023/A:1006570219058 PG 23 WC Engineering, Chemical SC Engineering GA XR953 UT WOS:A1997XR95300002 ER PT J AU Prior, SA Runion, GB Mitchell, RJ Rogers, HH Amthor, JS AF Prior, SA Runion, GB Mitchell, RJ Rogers, HH Amthor, JS TI Effects of atmospheric CO2 on longleaf pine: Productivity and allocation as influenced by nitrogen and water SO TREE PHYSIOLOGY LA English DT Article DE biomass partitioning; carbon dioxide; Pinus palustris; resource limitations ID CARBON-DIOXIDE; ELEVATED CO2; LIQUIDAMBAR-STYRACIFLUA; PLANT-RESPONSES; TAEDA SEEDLINGS; ENRICHMENT; GROWTH; PHOSPHORUS; STRESS; AVAILABILITY AB Longleaf pine (Pinus palustris Mill.) seedlings were exposed to two concentrations of atmospheric CO2 (365 or 720 mu mol mol(-1)) in combination with two N treatments (40 or 400 kg N ha(-1) year(-1)) and two irrigation treatments (target values of -0.5 or -1.5 MPa xylem pressure potential) in open-top chambers from March 1993 through November 1994. Irrigation treatments were imposed after seedling establishment (i.e., 19 weeks after planting). Seedlings were harvested at 4, 8, 12, and 20 months. Elevated CO2 increased biomass production only in the high-N treatment, and the relative growth enhancement was greater for the root system than for the shoot system. In water-stressed trees, elevated CO2 increased root biomass only at the final harvest. Root:shoot ratios were usually increased by both the elevated CO2 and low-N treatments. In the elevated CO2 treatment, water-stressed trees had a higher root:shoot ratio than well-watered trees as a result of a drought-induced increase in the proportion of plant biomass in roots. Well-watered seedlings consistently grew larger than water-stressed seedlings only in the high-N treatment. We conclude that available soil N was the controlling resource for the growth response to elevated CO2 in this study. Although some growth enhancement was observed in water-stressed trees in the elevated CO2 treatment, this response was contingent on available soil N. C1 AUBURN UNIV,SCH FORESTRY,AUBURN,AL 36849. JOSEPH W JONES ECOL RES CTR,NEWTON,GA 31770. LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV,LIVERMORE,CA 94550. LAWRENCE LIVERMORE NATL LAB,GLOBAL CLIMATE RES DIV,LIVERMORE,CA 94550. RP Prior, SA (reprint author), USDA ARS,NATL SOIL DYNAM LAB,POB 3439,AUBURN,AL 36831, USA. RI Amthor, Jeffrey/F-2696-2016 OI Amthor, Jeffrey/0000-0002-1410-6100 NR 41 TC 48 Z9 49 U1 1 U2 17 PU HERON PUBLISHING PI VICTORIA PA 202, 3994 SHELBOURNE ST, VICTORIA BC V8N 3E2, CANADA SN 0829-318X J9 TREE PHYSIOL JI Tree Physiol. PD JUN PY 1997 VL 17 IS 6 BP 397 EP 405 PG 9 WC Forestry SC Forestry GA XC799 UT WOS:A1997XC79900006 ER PT J AU Goyal, A Specht, ED Wang, ZL Kroeger, DM AF Goyal, A Specht, ED Wang, ZL Kroeger, DM TI Grain boundary studies of high-temperature superconducting materials using electron backscatter Kikuchi diffraction SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 6th Conference on Frontiers of Electron Microscopy in Materials Science CY JUN 04-07, 1996 CL OAK BROOK, IL SP Argonne Natl Lab, Lawrence Livermore Lab, Oak Ridge Natl Lab, Lawrence Berkeley Natl Lab, Los Alamos Natl Lab, UOP ID CRITICAL-CURRENT DENSITY; CU-O SUPERCONDUCTOR; TRANSPORT-PROPERTIES; THIN-FILMS; BICRYSTALS; DEPENDENCE; TEXTURE; PATHS; TAPES AB Grain orientation and grain boundary misorientation distributions in high critical current density, high-temperature superconductors were determined using electron backscatter Kikuchi diffraction. It is found that depending on the type of superconductor and the processing method used to fabricate it, there exist different scales of biaxial texture from no biaxial texture, local biaxial texture, to complete biaxial texture. Experimentally obtained grain boundary misorientation distributions (GBMDs) were found to be skewed significantly to low angles in comparison to what is expected on the basis of macroscopic texture alone, suggesting that minimization of energy may be a driving force during the processing of high critical current density materials. In addition, a higher than expected fraction of coincident-site lattice boundaries is observed. Examination of maps of grain boundary misorientations in spatially correlated grains, i.e. the grain boundary mesotexture, suggests the presence of percolative paths of high critical current density. A combination of orientation measurements, theoretical modeling of GBMDs and modeling of percolative current flow through an assemblage of grain boundaries is performed to gain an insight into the important microstructural features dictating the transport properties of high-temperature superconductors. It is found that maximization of low energy, in particular, low-angle boundaries, is essential for higher critical currents. The combination of experimental and analytical techniques employed are applicable to other materials where physical properties are dominated by intergranular characteristics. RP Goyal, A (reprint author), OAK RIDGE NATL LAB,DIV MET & CERAM,POB 2008,OAK RIDGE,TN 37831, USA. RI Wang, Zhong Lin/E-2176-2011; Specht, Eliot/A-5654-2009 OI Wang, Zhong Lin/0000-0002-5530-0380; Specht, Eliot/0000-0002-3191-2163 NR 36 TC 18 Z9 18 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN 1 PY 1997 VL 67 IS 1-4 BP 35 EP 57 DI 10.1016/S0304-3991(96)00105-2 PG 23 WC Microscopy SC Microscopy GA XJ574 UT WOS:A1997XJ57400006 ER PT J AU Buck, EC Fortner, JA AF Buck, EC Fortner, JA TI Detecting low levels of transuranics with electron energy loss spectroscopy SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 6th Conference on Frontiers of Electron Microscopy in Materials Science CY JUN 04-07, 1996 CL OAK BROOK, IL SP Argonne Natl Lab, Lawrence Livermore Lab, Oak Ridge Natl Lab, Lawrence Berkeley Natl Lab, Los Alamos Natl Lab, UOP DE electron energy loss spectroscopy; transmission electron microscopy; ultramicrotome; uranium; transuranics AB With the second difference electron energy loss spectroscopy (EELS) technique, transuranic (TRU) and rare-earth (RE) elements have been detected at low concentration levels (<200 ppm) in alteration phases formed during the laboratory corrosion of nuclear waste glass. Use of the high-energy M-4,M-5 edges to detect TRU elements is the only method available to positively identify them because the weaker lower-energy N-4,N-5 edges overlap with the more intense M-4,M-5 edges of the trace levels of REs that may be present in the same alteration phases. The position and intensity of the M-4,M-5 absorption edges of the TRU were confirmed with samples of transuranic contaminated soils and data from the literature, The M-4:M-5 ratio for the actinide absorption edges was used, in combination with crystal chemical considerations to determine chemical state. RP Buck, EC (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 13 TC 17 Z9 17 U1 2 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN 1 PY 1997 VL 67 IS 1-4 BP 69 EP 75 DI 10.1016/S0304-3991(96)00109-X PG 7 WC Microscopy SC Microscopy GA XJ574 UT WOS:A1997XJ57400008 ER PT J AU Fortner, JA Buck, EC Ellison, AJG Bates, JK AF Fortner, JA Buck, EC Ellison, AJG Bates, JK TI EELS analysis of redox in glasses for plutonium immobilization SO ULTRAMICROSCOPY LA English DT Article; Proceedings Paper CT 6th Conference on Frontiers of Electron Microscopy in Materials Science CY JUN 04-07, 1996 CL OAK BROOK, IL SP Argonne Natl Lab, Lawrence Livermore Lab, Oak Ridge Natl Lab, Lawrence Berkeley Natl Lab, Los Alamos Natl Lab, UOP DE electron energy loss spectroscopy; lanthanides; actinides; glass ID RARE-EARTH-OXIDES; ABSORPTION AB The chemical and structural environments of f-electron elements in glasses are the origin of many of the important optical, electronic, and magnetic properties of materials incorporating these elements. Thus, the oxidation state and chemical coordination of lanthanides and actinides in host materials constitute an important design consideration in optically active glasses, magnetic materials, perovskite superconductors, and nuclear waste materials. We have made use of the characteristic line shapes of cerium to determine its oxidation state in alkali borosilicate glasses that are being developed for immobilization of plutonium. Cerium, it should be noted, is often used as a ''surrogate'' element for plutonium in materials design because of its similar ionic size (for Pu in the +3 and +4 states) and preferred chemical coordination. The solubility of the plutonium (or cerium) in a waste glass will likely be determined by its redox state in the glass. By examining several compositions of prototype immobilization glass using electron energy loss spectroscopy (EELS), we found that the redox state of cerium doped to 7 wt% could be varied by a suitable choice of alkali elements in the glass formula. Preliminary results on plutonium-doped glasses confirm the design strategy employed, leading to 5 wt% (or more) plutonium being truly dissolved in the glass. RP Fortner, JA (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 10 TC 46 Z9 46 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD JUN 1 PY 1997 VL 67 IS 1-4 BP 77 EP 81 DI 10.1016/S0304-3991(96)00108-8 PG 5 WC Microscopy SC Microscopy GA XJ574 UT WOS:A1997XJ57400009 ER PT J AU Speed, RD AF Speed, RD TI International control of nuclear weapons (Reprinted from The International Control of Nuclear Weapons, June 1994) SO WASHINGTON QUARTERLY LA English DT Reprint RP Speed, RD (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU M I T PRESS PI CAMBRIDGE PA FIVE CAMBRIDGE CENTER, CAMBRIDGE, MA 02142 SN 0163-660X J9 WASH QUART JI Wash. Q. PD SUM PY 1997 VL 20 IS 3 BP 179 EP 184 PG 6 WC International Relations; Law SC International Relations; Government & Law GA XD293 UT WOS:A1997XD29300020 ER PT J AU Lipfert, FW AF Lipfert, FW TI Estimating exposure to methylmercury: Effects of uncertainties SO WATER AIR AND SOIL POLLUTION LA English DT Article; Proceedings Paper CT 4th International Conference on Mercury as a Global Pollutant CY AUG 04-08, 1996 CL HAMBURG, GERMANY SP Aluminium Co Amer (ALCOA), BSL Olefinverbund GMBH, City Hamburg, Deut Forschungsgemeinsch, Elect Power Res Inst, Environm Canada, AES, European Commiss, SM&T, Florida Dept Environm Protect, Frontier Geosci, USA, GKSS Res Ctr, Hlth Canada, MSB, Oak Ridge Natl Lab, US DOE, US EPA, Verein Freunde Forderer GKSS ID METHYL MERCURY; HUMAN-HAIR; UNITED-KINGDOM; DIET; FISH; BLOOD AB Uncertainties in exposures can lead to biased estimates of slopes and thresholds in the exposure-response relationships that are developed from regression analysis. This paper reviews published exposure and epidemiological studies of methylmercury (MeHg) from the perspective of the accuracy and precision of the estimates used to represent the actual doses received. Sources of such uncertainties, collectively referred to as ''exposure errors'', include instrumental and analytical errors, sampling and survey uncertainties, and individual variability in the relationships between the exposure metrics and the actual doses to target organs. Because the relationship between maternal intake and the consequent dose to the fetal brain varies among individuals, epidemiological studies of the effects of prenatal exposure must necessarily be accompanied by larger exposure uncertainties than comparable studies of effects on the mothers. The increased exposure errors typically result in attenuated slopes of the dose-response functions and under-estimates of thresholds, so that part of the apparent increased sensitivity of the fetus that has been developed from epidemiological studies may in fact be due to their inherently less certain exposures. Sources and magnitudes of exposure error found in the literature are discussed and their statistical ramifications are explored with Monte Carlo simulations. The paper also finds that, after adjusting for exposure error, the relationship between dietary intake and blood concentration is consistent with an average half-life shorter than has typically been used and that using population averages yields a consistent but sub-linear relationship between dietary intake of Hg and hair concentration. Investigators are urged to obtain (and present) data on more than one exposure metric, so that their relative uncertainties may be assessed independently. RP Lipfert, FW (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 41 TC 7 Z9 7 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD JUN PY 1997 VL 97 IS 1-2 BP 119 EP 145 PG 27 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA XL301 UT WOS:A1997XL30100013 ER PT J AU McCord, JT Gotway, CA Conrad, SH AF McCord, JT Gotway, CA Conrad, SH TI Impact of geologic heterogeneity on recharge estimation using environmental tracers: Numerical modeling investigation SO WATER RESOURCES RESEARCH LA English DT Article ID STATE-DEPENDENT ANISOTROPY; STOCHASTIC-ANALYSIS; UNSATURATED FLOW; SPATIAL VARIABILITY; SOLUTE TRANSPORT; DESERT SOILS; FIELD SOIL; MOVEMENT; TRITIUM AB This paper presents a numerical modeling approach for assessing the impacts of geologic heterogeneity on groundwater recharge estimates derived from environmental tracers. Common to many of the environmental tracer methods used to infer recharge in arid environments is an assumption of one-dimensional, vertical downward flow of water and solutes. However, in recent years there has been a growing recognition that fluid flux rates through geologic materials can be spatially variable owing to heterogeneities in porous media properties. Previous studies have suggested that local flow directions are dependent upon the stratigraphic and sedimentologic characteristics of the medium and may not be vertical even when application of water at the;surface is spatially uniform and hydraulic gradients are vertical. Consequently, environmental tracer movement will also be spatially variable, and the one-dimensional assumption invoked to interpret unsaturated environmental tracer concentration profiles may be unrealistic. Two different numerical simulation experiments were performed to investigate the problems with using environmental tracers to infer recharge. The first involves simulation of flow and tracer transport through heterogeneous Aat-lying media, and the second considers dipping layered anisotropic media. The results of these simulations show that recharge inferred using environmental tracer methods is also highly spatially variable and that recharge estimates obtained by tracer profiles tend to overestimate recharge and should be considered accurate only to within an order of magnitude, particularly in situations with significant media heterogeneity. Consequently, recharge estimates obtained from tracer profiles should be critically evaluated with regard to impacts of spatially variable flow. C1 UNIV NEBRASKA,DEPT BIOMETRY,LINCOLN,NE 68588. RP McCord, JT (reprint author), SANDIA NATL LABS,DEPT GEOHYDROL,MS 0727,ALBUQUERQUE,NM 87185, USA. NR 40 TC 23 Z9 23 U1 0 U2 3 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 JUN PY 1997 VL 33 IS 6 BP 1229 EP 1240 DI 10.1029/96WR03755 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA XC196 UT WOS:A1997XC19600003 ER PT J AU Tokunaga, TK Wan, JM AF Tokunaga, TK Wan, JM TI Water film flow along fracture surfaces of porous rock SO WATER RESOURCES RESEARCH LA English DT Article ID RELATIVE PERMEABILITY; WETTING LIQUID; INFILTRATION; MECHANISMS; RECHARGE; CORNERS; SOIL AB This study shows that hydraulic properties of individual fracture surfaces can be meaningfully defined and measured, and that water film flow is a mechanism contributing to fast, unsaturated flow in fractures. The hydraulic conductivity of an unconfined block of Bishop Tuff was measured dyer a range of near-zero matric potentials, where differences between hydraulic conductivities obtained without and with wax sealing of its lateral sides allowed isolation of film flow effects. Tensiometer and flux measurements showed that surface film flow in this system was significant for matric potentials greater (more positive) than about -250 Pa. In this range the average him thickness was shown to be potential dependent and proportional to the observed enhanced hydraulic conductivity. Measured average surface film thicknesses ranged from 2 to 70 mu m, with average film velocities in the range of 2 to 40 m d(-1) (about 10(3) times faster than that of the pore water under unit gradient saturated flow). Our experiments demonstrate that hydraulic properties of macroscopic surfaces of porous media are quantifiable, related to surface roughness, and potentially important in the how of water in vadose environments. This study further shows that contrary to existing conceptual models, unsaturated flow in fractures cannot generally be predicted solely on the basis of aperture distribution information. The high velocities of these surface films suggest that film flow can be an important mechanism contributing to fast flow in unsaturated fractures and macropores, especially in media characterized by low-permeability matrix and along regions of convergent flow in partially saturated fractures. RP Tokunaga, TK (reprint author), LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,MS 90-1116,BERKELEY,CA 94720, USA. RI Tokunaga, Tetsu/H-2790-2014; Wan, Jiamin/H-6656-2014 OI Tokunaga, Tetsu/0000-0003-0861-6128; NR 41 TC 140 Z9 146 U1 1 U2 24 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 JUN PY 1997 VL 33 IS 6 BP 1287 EP 1295 DI 10.1029/97WR00473 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA XC196 UT WOS:A1997XC19600008 ER PT J AU Mulholland, PJ Hill, WR AF Mulholland, PJ Hill, WR TI Seasonal patterns in streamwater nutrient and dissolved organic carbon concentrations: Separating catchment flow path and in-stream effects SO WATER RESOURCES RESEARCH LA English DT Article ID 2 FORESTED WATERSHEDS; WOODLAND STREAM; PHOSPHORUS DYNAMICS; PRIMARY PRODUCERS; HEADWATER STREAM; DECIDUOUS FOREST; MOUNTAIN STREAMS; SURFACE-WATER; NEW-YORK; ECOSYSTEM AB Distinct seasonal patterns in streamwater nutrient and dissolved organic carbon (DOC) concentrations are evident in the data record from 7 years of weekly sampling in the West Fork of Walker Branch (WB) and 4 years of weekly sampling in a nearby stream, upper White Oak Creek (WOC), both first-order streams in the Ridge and Valley Province of eastern Tennessee. Concentrations of NO3 and soluble reactive phosphorus (SRP) in both streams showed a repeated pattern of annual maxima in summer and biannual minima in autumn and spring. Concentrations of DOC in WB exhibited distinct autumn maxima. To determine whether temporal variations in catchment hydrological processes could explain the seasonal nutrient and DOC variations in WB, we used an end-member mixing analysis involving Ca and SO4 concentrations to separate stream discharge into three catchment how paths of differing nutrient concentrations. Stream NO3, SRP, and DOC concentrations were predicted solely on the basis of temporal variation in the importance of these how paths and measurements of nutrient concentrations for the different flow paths. Ratios of observed/predicted concentrations in stream water near 1.0 suggested that catchment effects alone explained streamwater concentrations, whereas ratios substantially different from 1.0 suggested that in-stream processes were important determinants of streamwater concentrations. Observed/predicted NO3 and SRP concentration ratios showed repeated annual patterns with values closer to 1.0 during winter and summer (generally 0.8-1.2) and minima (<0.6) in spring and autumn, suggesting substantial in-stream net uptake at these times. Observed/predicted DOC concentration ratios were more variable and generally greater than or equal to 1 but did show consistent autumn maxima (>2.5), indicating substantial in-stream DOC generation at this time. Observed/predicted ratios for all nutrients were generally less variable and were closer to 1.0 at high flow compared to low flow, suggesting that in-stream controls on streamwater chemistry are less important at high discharge than at low discharge. Our results indicate two general modes of control of stream nutrient concentrations: (1) catchment control via seasonal variation in the dominant hydrologic pathway (greater proportion of deep groundwater in summer), which produces lower winter and higher summer concentrations, and (2) in-stream control via high rates of net nutrient uptake during the spring (primarily by autotrophs) and autumn (primarily by heterotrophs). RP Mulholland, PJ (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Mulholland, Patrick/C-3142-2012 NR 55 TC 146 Z9 147 U1 0 U2 41 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 JUN PY 1997 VL 33 IS 6 BP 1297 EP 1306 DI 10.1029/97WR00490 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA XC196 UT WOS:A1997XC19600009 ER PT J AU Tokunaga, TK AF Tokunaga, TK TI A tensiometer for measuring hydraulic potentials on surfaces of porous rock SO WATER RESOURCES RESEARCH LA English DT Article AB A laboratory method for obtaining tensiometer measurements on surfaces of porous rock and soil is presented. The construction and performance of two versions of the ''surface tensiometer,'' developed for determining near-zero values of matric potential on rock surfaces, are described. Laboratory surface tensiometer measurements were made on a natural fracture surface of a Bishop Tuff block equilibrated with a water table boundary set at elevations ranging from -51 to +25 mm relative to the tensiometers. All equilibrium readings were within 10 Pa of ideal values, and most were within 5 Pa. Response times associated with this instrument-rock system were in qualitative agreement with the matric potential-dependent hydraulic properties of the rock block. RP Tokunaga, TK (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,MS 90-1116,BERKELEY,CA 94720, USA. RI Tokunaga, Tetsu/H-2790-2014 OI Tokunaga, Tetsu/0000-0003-0861-6128 NR 12 TC 4 Z9 4 U1 0 U2 0 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 JUN PY 1997 VL 33 IS 6 BP 1509 EP 1513 DI 10.1029/97WR00474 PG 5 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA XC196 UT WOS:A1997XC19600029 ER PT J AU McLeod, KW Ciravolo, TG AF McLeod, KW Ciravolo, TG TI Differential sensitivity of Nyssa aquatica and Taxodium distichum seedlings grown in fly ash amended sand SO WETLANDS LA English DT Article DE fly ash; boron; swamp; Taxodium distichum; Nyssa aquatica; baldcypress; water tupelo AB Nyssa aquatica and Taxodium distichum seedlings were grown for four months in sand amended with 0, 2.5, 5, and 10% fly ash (by weight). Leaf boron concentrations were linearly related to Ay ash addition up to the 5% treatment but did not increase in the 10% treatment. Taxodium distichum growth was not adversely affected by By asb addition. However, N. aquatica biomass, basal diameter, and height were reduced 75, 50, and 50%, respectively, al the two highest Ay ash rates. By differentially affecting the growth and vigor of seedlings of these two dominant woody species, regeneration of N. aquatica would be much less successful than T. distichum in wetlands containing fly ash. RP McLeod, KW (reprint author), UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,PO DRAWER E,AIKEN,SC 29802, USA. NR 14 TC 4 Z9 5 U1 0 U2 0 PU SOC WETLAND SCIENTISTS PI LAWRENCE PA 810 E TENTH ST, P O BOX 1897, LAWRENCE, KS 66044 SN 0277-5212 J9 WETLANDS JI Wetlands PD JUN PY 1997 VL 17 IS 2 BP 330 EP 335 PG 6 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA XG356 UT WOS:A1997XG35600015 ER PT J AU Zhang, CT Bhattacharyya, P Daly, PJ Broda, R Grabowski, ZW Nisius, D Ahmad, I Carpenter, MP Lauritsen, T Morss, LR Urban, W Durell, JL Phillips, WR Leddy, MJ Smith, AG Varley, BJ Schulz, N Lubkiewicz, E Bentaleb, M Blomqvist, J AF Zhang, CT Bhattacharyya, P Daly, PJ Broda, R Grabowski, ZW Nisius, D Ahmad, I Carpenter, MP Lauritsen, T Morss, LR Urban, W Durell, JL Phillips, WR Leddy, MJ Smith, AG Varley, BJ Schulz, N Lubkiewicz, E Bentaleb, M Blomqvist, J TI (nu f(7/2))(2) multiplet and E2 effective charge in Sn-134(50)84 SO ZEITSCHRIFT FUR PHYSIK A-HADRONS AND NUCLEI LA English DT Article ID ISOMERS AB By analysis of fission product gamma-rays measured at Eurogam II using a Cm-248 source, the (nu f(7/2))(2) multiplet in the N = 84 nucleus Sn-134 has been identified up to a 6(+) isomeric state at 1246 keV. The B(E2; 6(+)-->4(+)) is determined to be 36+/-7 e(2)fm(4) corresponding to a nu f(7/2) E2 effective charge of 1.01+/-0.10 e. C1 PURDUE UNIV,DEPT PHYS,W LAFAYETTE,IN 47907. ARGONNE NATL LAB,DIV PHYS,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. UNIV MANCHESTER,DEPT PHYS & ASTRON,MANCHESTER M13 9PL,LANCS,ENGLAND. UNIV STRASBOURG 1,CTR RECH NUCL,F-67037 STRASBOURG,FRANCE. ROYAL INST TECHNOL,DEPT PHYS FRESCATI,S-10405 STOCKHOLM,SWEDEN. RP Zhang, CT (reprint author), PURDUE UNIV,DEPT CHEM,W LAFAYETTE,IN 47907, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 9 TC 43 Z9 43 U1 0 U2 1 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 JUN PY 1997 VL 358 IS 1 BP 9 EP 10 DI 10.1007/s002180050269 PG 2 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA XG691 UT WOS:A1997XG69100004 ER PT J AU Pines, D AF Pines, D TI Nearly antiferromagnetic Fermi liquids: A progress report SO ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER LA English DT Article; Proceedings Paper CT Euroconference on Correlations in Unconventional Quantum Liquids CY OCT 07-11, 1996 CL EVORA, PORTUGAL SP Inst Sci & Technol Adv Studies ID SUPERCONDUCTIVITY AB I describe recent theoretical and experimental progress in understanding the physical properties of the two dimensional nearly antiferromagnetic Fermi liquids (NAFL's) found in the normal state of the cuprate superconductors. In such NAFL's, the magnetic interaction between planar quasiparticles is strong and peaked at or near the commensurate wave vector, Q = (pi, pi). For the optimally doped and underdoped systems, the resulting strong antiferromagnetic correlations produce three distinct magnetic phases in the normal state: mean field above T-cr, pseudoscaling between T-cr and T*, and pseudogap below T*. I present arguments which suggest that the physical origin of the pseudogap found in the quasiparticle spectrum below T-cr is the formation of a precursor to a spin-density-wave-state, describe the calculations based on this scenario of the dynamical spin susceptibility, Fermi surface evolution, transport, and Hall effect, and summarize the experimental evidence in its support. C1 UNIV ILLINOIS, DEPT PHYS, URBANA, IL 61801 USA. RP Pines, D (reprint author), LOS ALAMOS NATL LAB, CTR NONLINEAR STUDIES, LOS ALAMOS, NM 87545 USA. NR 22 TC 119 Z9 119 U1 0 U2 2 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 JUN PY 1997 VL 103 IS 2 BP 129 EP 135 DI 10.1007/s002570050346 PG 7 WC Physics, Condensed Matter SC Physics GA XD665 UT WOS:A1997XD66500005 ER PT J AU Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M DePasquale, S 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 Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB 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 Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P GrossKnetter, J Haas, T Hain, W Hasell, D Hessling, H Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burrow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyel, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE 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, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Nakao, M Tokushuku, K Yamada, S Yamazaki, Y An, SH Lee, SB Nam, SW Park, HS Park, SK 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 Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Shumilin, AV Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS 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 Okrasinski, JR Whitmore, JJ Iga, Y DAgostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Kananov, S Levy, A Abe, T Inuzuka, M Nagano, K Suzuki, I Umemori, K Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC 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 Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB AF Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G Romeo, GC Castellini, G Cifarelli, L Cindolo, F Contin, A Corradi, M DePasquale, S 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 Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Arneodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB 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 Fricke, U Gilkinson, DJ Glasman, C Gottlicher, P GrossKnetter, J Haas, T Hain, W Hasell, D Hessling, H Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Ryan, JJ Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burrow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyel, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE 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, SM Wu, JT Cloth, P Filges, D Fleck, JI Ishii, T Kuze, M Nakao, M Tokushuku, K Yamada, S Yamazaki, Y An, SH Lee, SB Nam, SW Park, HS Park, SK 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 Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Khein, LA Korotkova, NA Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Shumilin, AV Solomin, AN Zotkin, SA Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, M Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS 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 Okrasinski, JR Whitmore, JJ Iga, Y DAgostini, G Marini, G Nigro, A Raso, M Hart, JC McCubbin, NA Shah, TP Barberis, E Dubbs, T Heusch, C VanHook, M Lockman, W Rahn, JT Sadrozinski, HFW Seiden, A Williams, DC Schwarzer, O Walenta, AH Abramowicz, H Briskin, G Dagan, S Doeker, T Kananov, S Levy, A Abe, T Inuzuka, M Nagano, K Suzuki, I Umemori, K Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC 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 Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB TI Measurement of elastic J/upsilon photoproduction at HERA SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID CENTRAL TRACKING DETECTOR; ZEUS BARREL CALORIMETER; LUND MONTE-CARLO; CROSS-SECTION; PROTON; J/PSI; CONSTRUCTION; DESIGN; SCATTERING; ENERGY AB The reaction a p --> J/psi p has been studied in epsilon p interactions using the ZEUS detector at HERA. The cross section for elastic J/psi photoproduction has been measured as a function of the photon-proton centre of mass energy W in the range 40 < W < 140 GeV at a median photon virtuality Q(2) of 5 x 10(-5) GEV(2). The photoproduction cross section, sigma(ap-->J/psi p), is observed to rise steeply with W. A fit to the data presented in this paper to determine the parameter delta in the form sigma(ap-->J/psi p) proportional to W-delta yields the value delta=0.92+/-0.14+/-0.10. The differential cross section d sigma/d\t\ is presented over the range \t\ < 1.0 GEV(2) where t is the square of the four-momentum exchanged at the proton vertex. d sigma/d\t\ falls exponentially with a slope parameter of 4.6+/-0.4(-0.6)(+0.4) GEV(-2). The measured decay angular distrubitions are consistent with 8-channel helicity conservation. C1 ANDREWS UNIV, BERRIEN SPRINGS, MI 49104 USA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BOLOGNA, BOLOGNA, ITALY. UNIV BONN, INST PHYS, D-5300 BONN, GERMANY. UNIV BRISTOL, HH WILLS PHYS LAB, BRISTOL BS8 1TL, AVON, ENGLAND. UNIV CALABRIA, DEPT PHYS, I-87036 COSENZA, ITALY. IST NAZL FIS NUCL, COSENZA, ITALY. CHONNAM NATL UNIV, KWANGJU, SOUTH KOREA. COLUMBIA UNIV, NEVIS LABS, IRVINGTON, NY USA. INST NUCL PHYS, KRAKOW, POLAND. ACAD MIN & MET, FAC PHYS & NUCL TECHNIQUES, KRAKOW, POLAND. JAGIELLONIAN UNIV, DEPT PHYS, KRAKOW, POLAND. DESY, D-2000 HAMBURG, GERMANY. DESY, IFH ZEUTHEN, 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-7800 FREIBURG, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW, LANARK, SCOTLAND. UNIV HAMBURG, INST EXPT PHYS 1, HAMBURG, GERMANY. UNIV HAMBURG, INST EXPT PHYS 2, D-2000 HAMBURG, GERMANY. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, HIGH ENERGY NUCL PHYS GRP, LONDON, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. UNIV OXFORD, DEPT PHYS, OXFORD, ENGLAND. UNIV PADUA, DIPARTIMENTO FIS, PADUA, ITALY. IST NAZL FIS NUCL, PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIVERSITY PK, PA 16802 USA. POLYTECH UNIV, SAGAMIHARA, KANAGAWA, JAPAN. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. IST NAZL FIS NUCL, ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, D-5900 SIEGEN, GERMANY. TEL AVIV UNIV, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, SCH PHYS, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, DEPT PHYS, TOKYO 113, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO, JAPAN. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, TURIN, ITALY. IST NAZL FIS NUCL, I-10125 TURIN, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO, ON, CANADA. UCL, DEPT PHYS & ASTRON, LONDON, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, DEPT PHYS, BLACKSBURG, VA 24061 USA. UNIV WARSAW, INST EXPT PHYS, WARSAW, POLAND. INST NUCL STUDIES, PL-00681 WARSAW, POLAND. WEIZMANN INST SCI, INST NUCL PHYS, IL-76100 REHOVOT, ISRAEL. UNIV WISCONSIN, DEPT PHYS, MADISON, WI 53706 USA. YORK UNIV, DEPT PHYS, N YORK, ON M3J 1P3, CANADA. IROE, FLORENCE, ITALY. RP Breitweg, J (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Graciani Diaz, Ricardo/I-5152-2016; Morandin, Mauro/A-3308-2016; Solomin, Anatoly/C-3072-2016; Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; 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; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011 OI Graciani Diaz, Ricardo/0000-0001-7166-5198; Kasemann, Matthias/0000-0002-0429-2448; Arneodo, Michele/0000-0002-7790-7132; Abbiendi, Giovanni/0000-0003-4499-7562; Morandin, Mauro/0000-0003-4708-4240; De Pasquale, Salvatore/0000-0001-9236-0748; Katz, Uli/0000-0002-7063-4418; Wiggers, Leo/0000-0003-1060-0520; Hernandez Calama, Jose Maria/0000-0001-6436-7547; Gladilin, Leonid/0000-0001-9422-8636 NR 59 TC 87 Z9 87 U1 1 U2 3 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 JUN PY 1997 VL 75 IS 2 BP 215 EP 228 DI 10.1007/s002880050464 PG 14 WC Physics, Particles & Fields SC Physics GA XL031 UT WOS:A1997XL03100003 ER PT J AU Smith, J Vogt, R AF Smith, J Vogt, R TI Charm and bottom quark production cross sections near threshold SO ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS LA English DT Article ID PRINCIPAL-VALUE RESUMMATION; HADRON HADRON-COLLISIONS; PI-EMULSION INTERACTIONS; PARTON DISTRIBUTIONS; DRELL-YAN; GEV/C-PI; MESON PRODUCTION; QCD CORRECTIONS; NUCLEON; PHOTON AB The cross sections for charm and bottom quark production in the threshold region are discussed. We consider the effects of an all order resummation of initial state soft-plus-virtual gluon radiation on the total cross sections compared to the order alpha(s)(3) results. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. RP Smith, J (reprint author), SUNY STONY BROOK,INST THEORET PHYS,STONY BROOK,NY 11794, USA. NR 42 TC 19 Z9 19 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 JUN PY 1997 VL 75 IS 2 BP 271 EP 276 DI 10.1007/s002880050470 PG 6 WC Physics, Particles & Fields SC Physics GA XL031 UT WOS:A1997XL03100009 ER PT J AU Reinsch, VE Kelley, SS AF Reinsch, VE Kelley, SS TI Crystallization of poly(hydroxybutyrate-co-hydroxyvalerate) in wood fiber-reinforced composites SO JOURNAL OF APPLIED POLYMER SCIENCE LA English DT Article ID POLY(PHENYLENE SULFIDE) COMPOSITES; BACTERIAL POLY(BETA-HYDROXYBUTYRATE-CO-BETA-HYDROXYVALERATE); POLY(3-HYDROXYBUTYRATE-CO-3-HYDROXYVALERATE); BEHAVIOR; POLY(ETHYLENE-TEREPHTHALATE); HYDROXYVALERATE; SPECTROSCOPY; POLYMER; PHASE AB Wood fiber-reinforced composites were prepared from poly(hydroxybuty rate) (PHB) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHB/HV) copolymers containing 9 and 24% valerate. The effects of fibers on crystallization-were investigated. Thermomechanical pulp, bleached Kraft fibers, and microcrystalline cellulose filler were used as the reinforcing phase. The crystallization of PHB/HV in composite materials was examined using Modulated Differential Scanning Calorimetry (MDSC) and hot-stage microscopy. Hot-stage microscopy showed that polymer crystallites are nucleated on the fiber surface and that the density of nuclei was greater in fiber-reinforced composites than in unfilled material. Dynamic crystallization experiments showed that bleached Kraft, thermomechanical pulp, and microcrystalline cellulose increased the crystallization rate of PHB and PHB/HV both from the glass and melt. However, ultimate crystallinity determined from the heat of crystallization was the same in unreinforced and reinforced materials. The kinetics of PHB/HV crystallization were examined using nonisothermal Avrami-type analysis. Unreinforced and Kraft-reinforced PHB were characterized and compared with unreinforced PHB/9%HV. The Avrami exponent of crystallization, related to nucleation mechanism and growth morphology, is 2.0 for unreinforced PHB, 2.8 for kraft-reinforced PHB, and 3.0 for unreinforced PHB/9%HV. (C) 1997 John Wiley & Sons, Inc. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. NR 21 TC 63 Z9 63 U1 3 U2 14 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 MAY 31 PY 1997 VL 64 IS 9 BP 1785 EP 1796 PG 12 WC Polymer Science SC Polymer Science GA WW913 UT WOS:A1997WW91300015 ER PT J AU Otto, F Thornell, AP Crompton, T Denzel, A Gilmour, KC Rosewell, IR Stamp, GWH Beddington, RSP Mundlos, S Olsen, BR Selby, PB Owen, MJ AF Otto, F Thornell, AP Crompton, T Denzel, A Gilmour, KC Rosewell, IR Stamp, GWH Beddington, RSP Mundlos, S Olsen, BR Selby, PB Owen, MJ TI Cbfa1, a candidate gene for cleidocranial dysplasia syndrome, is essential for osteoblast differentiation and bone development SO CELL LA English DT Article ID EXPRESSION; FAMILY AB We have generated Cbfa1-deficient mice. Homozygous mutants die of respiratory failure shortly after birth. Analysis of their skeletons revealed an absence of osteoblasts and bane. Heterozygous mice showed specific skeletal abnormalities that are characteristic of the human heritable skeletal disorder, cleidocranial dysplasia (CCD). These defects are also observed in a mouse Ccd mutant for this disease. The Cbfa1 gene was shown to be deleted in the Ccd mutation. Analysis of embryonic Cbfa1 expression using a lacZ reporter gene revealed strong expression at sites of bone formation prior to the earliest stages of ossification. Thus, the Cbfa1 gene is essential for osteoblast differentiation and bone formation, and the Cbfa1 heterozygous mouse is a paradigm for a human skeletal disorder. C1 IMPERIAL CANC RES FUND,LINCOLNS INN FIELDS,LONDON WC2A 3PX,ENGLAND. HAMMERSMITH HOSP,ROYAL POSTGRAD MED SCH,DEPT HISTOPATHOL,LONDON W12 0HS,ENGLAND. NATL INST MED RES,LONDON NW7 1AA,ENGLAND. HARVARD UNIV,SCH MED,DEPT CELL BIOL,BOSTON,MA 02115. OAK RIDGE NATL LAB,DIV LIFE SCI,OAK RIDGE,TN 37830. FU NIAMS NIH HHS [AR36819] NR 19 TC 1847 Z9 1906 U1 5 U2 48 PU CELL PRESS PI CAMBRIDGE PA 1050 MASSACHUSETTES AVE, CIRCULATION DEPT, CAMBRIDGE, MA 02138 SN 0092-8674 J9 CELL JI Cell PD MAY 30 PY 1997 VL 89 IS 5 BP 765 EP 771 DI 10.1016/S0092-8674(00)80259-7 PG 7 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA XB925 UT WOS:A1997XB92500013 PM 9182764 ER PT J AU Deutsch, PW Curtiss, LA Blaudeau, JP AF Deutsch, PW Curtiss, LA Blaudeau, JP TI Binding energies of germanium clusters, Ge-n (n=2-5) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SMALL SILICON CLUSTERS; ELECTRONIC-STRUCTURE; GAUSSIAN-2 THEORY; GROUND-STATE; 3RD-ROW ATOMS; LYING STATES; GA-KR; SURFACES; CURVES; SI-3 AB Gaussian-2 (G2) theory for third-row non-transition elements is used to calculate energies of germanium clusters, Ge-n (n = 2-5). The G2 energies are used to derive accurate binding energies for the clusters. The results for Ge-2 and Ge-3 are in agreement with experiment while there is some disagreement for Ge-4 and Ge-5. The binding energies are also calculated using the B3LYP density functional method with the 6-311 + G(3df,2p) basis set and compared with the G2 results and experiment. C1 ARGONNE NATL LAB,DIV CHEM TECHNOL,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV SCI MAT,ARGONNE,IL 60439. RP Deutsch, PW (reprint author), PENN STATE UNIV,DEPT PHYS,MONACA,PA 15061, USA. NR 34 TC 46 Z9 46 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 30 PY 1997 VL 270 IS 5-6 BP 413 EP 418 DI 10.1016/S0009-2614(97)00398-9 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB517 UT WOS:A1997XB51700005 ER PT J AU Curtiss, LA Raghavachari, K Redfern, PC Pople, JA AF Curtiss, LA Raghavachari, K Redfern, PC Pople, JA TI Investigation of the use of B3LYP zero-point energies and geometries in the calculation of enthalpies of formation SO CHEMICAL PHYSICS LETTERS LA English DT Article ID GAUSSIAN-2 THEORY; SCALING FACTORS; FORCE-FIELDS; FREQUENCIES AB The use of B3LYP/6-31G* zero-point energies and geometries in the calculation of enthalpies of formation has been investigated for the enlarged G2 test set of 148 molecules [J. Chem. Phys. 106 (1997) 1063]. A scale factor of 0.96 for the B3LYP zero-point energies gives an average absolute deviation nearly the same as scaled HF/6-31G'' zero-point energies for G2, G2(MP2), and B3LYP/6-311 + G(3df,2p) enthalpies. A scale factor of 0.98, which has been recommended in some studies, increases the average absolute deviation by about 0.2 kcal/mol. Geometries from B3LYP/6-31G* are found to do as well as MP2/6-31G* geometries in the calculation of the enthalpies of formation. C1 LUCENT TECHNOL, BELL LABS, MURRAY HILL, NJ 07974 USA. NORTHWESTERN UNIV, DEPT CHEM, EVANSTON, IL 60208 USA. RP Curtiss, LA (reprint author), ARGONNE NATL LAB, DIV CHEM TECHNOL, DIV MAT SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 23 TC 145 Z9 146 U1 2 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 30 PY 1997 VL 270 IS 5-6 BP 419 EP 426 DI 10.1016/S0009-2614(97)00399-0 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB517 UT WOS:A1997XB51700006 ER PT J AU Enderlein, J Goodwin, PM VanOrden, A Ambrose, WP Erdmann, R Keller, RA AF Enderlein, J Goodwin, PM VanOrden, A Ambrose, WP Erdmann, R Keller, RA TI A maximum likelihood estimator to distinguish single molecules by their fluorescence decays SO CHEMICAL PHYSICS LETTERS LA English DT Article ID LASER-INDUCED FLUORESCENCE; FLOWING SAMPLE STREAMS; IDENTIFICATION AB We have developed a maximum likelihood estimator to distinguish between similar molecules at the single molecule level based upon fluorescence decay measurements. Time-resolved fluorescence measurements for single Rhodamine 6G and tetramethylrhodamine isothiocyanate molecules in fluid flow are derived from time-correlated single photon counting. A maximum likelihood estimator is developed and applied to data from a mixture of molecules. Single molecules are identified and distinguished by their fluorescence time decays. Comparison is made between identification error rates and theoretical predictions. To our knowledge, this is the first reported example of single molecule identification by fluorescence decay in a mixture. C1 PICOQUANT GMBH,D-12489 BERLIN,GERMANY. RP Enderlein, J (reprint author), LOS ALAMOS NATL LAB,CST-1,MS M888,LOS ALAMOS,NM 87545, USA. RI Van Orden, Alan/N-4219-2015 NR 19 TC 58 Z9 58 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 30 PY 1997 VL 270 IS 5-6 BP 464 EP 470 DI 10.1016/S0009-2614(97)00409-0 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB517 UT WOS:A1997XB51700011 ER PT J AU Thiesemann, H Taatjes, CA AF Thiesemann, H Taatjes, CA TI Temperature dependence of the reaction C2H(C2D)+O-2 between 295 and 700 K SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RATE-CONSTANT MEASUREMENTS; MOLECULAR-OXYGEN; VINYL RADICALS; C2H; KINETICS; O-2; CH; SPECTROSCOPY; ACETYLENE; MECHANISM AB The rate coefficients for the reactions of C2H and C2D with O-2 have been measured in the temperature range 295 K less than or equal to T less than or equal to 700 K. Both reactions show a slightly negative temperature dependence in this temperature range, with k(C2H+O2) = (3.15 +/- 0.04) x 10(-11) (T/295 K)(-(0.16+/-0.02)) cm(3) molecule(-1) s(-1). The kinetic isotope effect is k(C2H)/k(C2D) = 1.04 +/- 0.03 and is constant with temperature to within experimental error. The temperature dependence and the C2H + O-2 kinetic isotope effect are consistent with a capture-limited metathesis reaction, and suggest that formation of the initial HCCOO adduct is rate-limiting. RP Thiesemann, H (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,MAIL STOP 9055,LIVERMORE,CA 94551, USA. NR 34 TC 22 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 30 PY 1997 VL 270 IS 5-6 BP 580 EP 586 DI 10.1016/S0009-2614(97)00396-5 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB517 UT WOS:A1997XB51700027 ER PT J AU Muddiman, DC Huang, BM Anderson, GA Rockwood, A Hofstadler, SA WeirLipton, MS Proctor, A Wu, QY Smith, RD AF Muddiman, DC Huang, BM Anderson, GA Rockwood, A Hofstadler, SA WeirLipton, MS Proctor, A Wu, QY Smith, RD TI Application of sequential paired covariance to liquid chromatography mass spectrometry data - Enhancements in both the signal-to-noise ratio and the resolution of analyte peaks in the chromatogram SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE sequential paired covariance; chemometrics; signal-to-noise ratio; resolution ID STAPHYLOCOCCAL PROTEASE; IONIZATION AB The algorithm of sequential paired covariance (SPC) has been previously reported to dramatically enhance the signal-to-noise (S/N) ratio for on-line separations combined with mass spectrometry. That initial study focused on a limited number of data sets derived from the combination of capillary electrophoresis (CE) with time-of-flight mass spectrometry using an electrospray interface. Results from the initial study clearly demonstrated that a significant enhancement (almost two orders of magnitude) in the S/N ratio of the eluting peaks in the electropherogram could be obtained, facilitating identification of the analytes. In this report, the algorithm has been applied to liquid chromatography-mass spectrometry data obtained on a triple quadrupole instrument and we have evaluated the general applicability of the SPC approach to several types of microcolumn separations with mass spectrometric detection, including CE coupled with Fourier transform ion cyclotron resonance mass spectrometry. In all the cases we tested, we found the algorithm enhanced the S/N ratios of the resulting chromatograms or electropherograms to a similar extent. This report further demonstrates the SPC approach to enhance the resolution as well as the S/N ratio of the eluting peaks of a complex peptide mixture. While many variations of the algorithm are possible, we have also found higher order covariance (e.g., 3rd order) is useful for eliminating coincidental noise in sequential mass spectra, giving the potential to extract broad, low intensity analyte peaks. We also demonstrate the sequential covariance approach for enhancing the SIN ratio of mass spectra. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 NR 15 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 30 PY 1997 VL 771 IS 1-2 BP 1 EP 7 DI 10.1016/S0021-9673(97)00069-1 PG 7 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XF413 UT WOS:A1997XF41300001 ER PT J AU Mayer, DL Fritz, JS AF Mayer, DL Fritz, JS TI Silicalite as a sorbent for solid-phase extraction SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE silicalite; solid-phase extraction; stationary phases, LC; alcohols; aldehydes; esters; ketones ID SILICONE-RUBBER MEMBRANES; ORGANIC-COMPOUNDS; ADSORPTION EQUILIBRIA; MOLECULAR-SIEVE; ZEOLITE; HYDROCARBONS; DIFFUSION; SEPARATION; PERVAPORATION; SORPTION AB A molecular sieve known as Silicalite was used as a sorbent for solid-phase extraction (SPE) of organic analytes from aqueous samples. Silicalite contains an intricate system of channels approximately 6 Angstrom in diameter, but unlike most other molecular sieves the channels of Silicalite are able to retain organic compounds by hydrophobic attraction. Small hydrophilic compounds, such as the lower alcohols, aldehydes, esters and ketones, are well extracted by Silicalite, thus adding a valuable new capability to conventional SPE. Extensive data are presented to define the scope and limitations of Silicalite for SPE. Breakthrough curves were used for several compounds to determine their loading capacity on Silicalite. C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. US DOE,AMES LAB,AMES,IA 50011. NR 55 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 30 PY 1997 VL 771 IS 1-2 BP 45 EP 53 DI 10.1016/S0021-9673(97)00131-3 PG 9 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XF413 UT WOS:A1997XF41300005 ER PT J AU Zhang, X Studier, FW AF Zhang, X Studier, FW TI Mechanism of inhibition of bacteriophage T7 RNA polymerase by T7 lysozyme SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE T7 RNA polymerase; T7 lysozyme; transcription inhibition; transcription initiation; pausing and termination ID RIBONUCLEIC-ACID POLYMERASE; ESCHERICHIA-COLI; NUCLEOTIDE-SEQUENCE; T7-RNA POLYMERASE; CLONED GENES; TRANSCRIPTION; TERMINATION; DNA; EXPRESSION; PROMOTER AB Bacteriophage T7 lysozyme is known to inhibit transcription by T7 RNA polymerase. Lysozyme present before initiation inhibited the synthesis of long RNA chains but did not inhibit elongation when added shortly after chains were initiated. A combination of gel-shift and transcription assays showed that lysozyme and polymerase form a 1:1 complex that binds promoter DNA and makes abortive transcripts, indicating that lysozyme has little effect on the early steps of transcription. Extension of stalled transcription complexes suggested that a transcribing polymerase becomes resistant to lysozyme inhibition after synthesis of an RNA chain as short as 15 nucleotides. It seems likely that bound lysozyme prevents an initiating polymerase from converting to an elongation complex. This conversion is thought to involve both a conformational change in the polymerase and the binding of nascent RNA. Gel-shift experiments indicated that lysozyme does not interfere with the binding of RNA, so it probably prevents a necessary conformational change in the polymerase. Lysozyme also increased pausing or termination at two sites in lambda DNA and at a site near the right end of the concatemer junction of T7 DNA. If pausing at these sites involves a reversal from the elongation to the initiation conformation, lysozyme may increase pausing or termination by ''locking in'' the initiation conformation. The arrest of transcription complexes near promoters and near the right end of the concatemer junction almost certainly must relate to lysozyme's ability to stimulate replication, maturation and packaging of T7 DNA during T7 infection. (C) 1997 Academic Press Limited. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NR 41 TC 45 Z9 49 U1 1 U2 9 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD MAY 30 PY 1997 VL 269 IS 1 BP 10 EP 27 DI 10.1006/jmbi.1997.1016 PG 18 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XB844 UT WOS:A1997XB84400002 PM 9192997 ER PT J AU Lyakhov, DL He, B Zhang, X Studier, FW Dunn, JJ McAllister, WT AF Lyakhov, DL He, B Zhang, X Studier, FW Dunn, JJ McAllister, WT TI Mutant bacteriophage T7 RNA polymerases with altered termination properties SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE RNA binding; T7 lysozyme; concatamer junction; packaging; phage RNA polymerase ID NUCLEOTIDE-SEQUENCE; T7-RNA POLYMERASE; TRANSCRIPTION; GENE; DNA; INITIATION; LYSOZYME; PROCESSIVITY; MUTAGENESIS; EXPRESSION AB We have identified mutants of bacteriophage T7 RNA polymerase (RNAP) that are altered in their ability to pause or terminate at a variety of signals. These signals include a terminator found fortuitously in the human preproparathyroid hormone (PTH) gene, a pause site found in the concatamer junction (CT) of replicating T7 DNA, and termination signals that are also utilized by Escherichia coli RNAP (e.g. rrnB T1 and T2). Whereas the mutant enzymes terminate normally at the late terminator in T7 DNA (T Phi) and rrnB T2, they fail to terminate at one of the termination sites of rrnB T1, and also fail to recognize the PTH and CJ signals. The mutant enzymes exhibit normal processivity on linear templates, but show a slightly reduced processivity on supercoiled templates and terminate more efficiently when synthesizing poly(U) tracts. The mutant enzymes also show a decreased tendency to produce aberrant transcription products from DNA templates having protruding 3' ends. T7 lysozyme (an inhibitor of T7 RNAP) has been shown to exert its action by preventing the transition of the RNAP from an unstable initiation complex (IC) to a stable elongation complex (EC). We have found that T7 lysozyme enhances recognition of CT by wild-type T7 RNAP, and that mutant T7 RNAPs that show increased sensitivity to lysozyme show enhanced recognition of this signal, even in the absence of lysozyme. These results, together with the observation that the mutations that result in the termination-deficient phenotype affect a region of the RNAP that has been implicated in RNA binding and upstream promoter contacts, support the hypothesis that, in some cases, termination represents a reversal of the events that occur during initiation. (C) 1997 Academic Press Limited. C1 SUNY HLTH SCI CTR,DEPT MICROBIOL & IMMUNOL,MORSE INST MOL GENET,BROOKLYN,NY 11203. RUSSIAN ACAD SCI,VA ENGELHARDT MOL BIOL INST,MOSCOW 117984,RUSSIA. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. FU NIGMS NIH HHS [GM38147] NR 43 TC 53 Z9 53 U1 0 U2 5 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD MAY 30 PY 1997 VL 269 IS 1 BP 28 EP 40 DI 10.1006/jmbi.1997.1015 PG 13 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XB844 UT WOS:A1997XB84400003 PM 9192998 ER PT J AU Chang, KY Tinoco, I AF Chang, KY Tinoco, I TI The structure of an RNA ''kissing'' hairpin complex of the HIV TAR hairpin loop and its complement SO JOURNAL OF MOLECULAR BIOLOGY LA English DT Article DE NMR spectroscopy; RNA-RNA interactions; kissing hairpin complex; alternating helical twist; RNA-protein recognition ID COLE1 ROM PROTEIN; NMR-SPECTROSCOPY; COUPLING-CONSTANTS; H-1 RESONANCES; 434 REPRESSOR; STEM-LOOPS; DNA; RECOGNITION; OPERATOR; CONFORMATION AB We have used nuclear magnetic resonance (NMR) to obtain the structure of an RNA ''kissing'' hairpin complex formed between the HIV-2 TAR hairpin loop and a hairpin with a complementary loop sequence. Kissing hairpins are important in natural antisense reactions; their complex is a specific target for protein binding. The complex has all six nucleotides of each loop paired to form a bent quasicontinuous helix of three coaxially stacked helices: two stems plus a loop-loop interaction helix. Experimental constraints derived from heteronuclear and homonuclear NMR data on C-13 and N-15-labeled RNA led to a structure for the loop-loop helix with an average root-mean-square deviation of 0.83 (+/-0.10) A for 33 converged structures relative to the average structure. The loop-loop helix of the kissing complex is distorted compared to A-form RNA. Its major groove is blocked by the phosphodiester bonds that connect the first loop residue of each hairpin with its own stem, and it is flanked two negatively charged phosphate clusters. The loop-loop helix has alternating helical twists between adjacent base-pairs. The base-pairs at the helix junctions are overwound and three base-pairs near the helix junctions adopt high propeller twists. All these changes reduce the distance needed for the bridging phosphodiester bends connecting each stem and loop to cross the major groove of the loop-loop helix, and result in a deformed RNA helix with localized perturbations in the minor groove surface. The alternating helical tu ist pattern, plus other distortions in the loop-loop helix may be important for Rom protein recognition of the kissing hairpin complex. (C) Academic Press Limited. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 10840] NR 60 TC 99 Z9 99 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-2836 J9 J MOL BIOL JI J. Mol. Biol. PD MAY 30 PY 1997 VL 269 IS 1 BP 52 EP 66 DI 10.1006/jmbi.1997.1021 PG 15 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XB844 UT WOS:A1997XB84400005 PM 9193000 ER PT J AU Arnett, D Bazan, G AF Arnett, D Bazan, G TI Nucleosynthesis in stars: Recent developments SO SCIENCE LA English DT Article ID GAMMA-RAY LINE; NEUTRINO-DRIVEN WINDS; METAL-POOR STARS; SUPERNOVA 1987A; COMPTEL OBSERVATIONS; PROTONEUTRON STARS; HALO STARS; EMISSION; SN-1987A; CONVECTION AB The development of new observational, experimental, and computational technologies is changing our understanding of the origins of the elements by thermonuclear burning in stars. Gamma-ray lines from newly made radioactive nuclei have been identified using instruments onboard low-Earth orbiting satellites. Grains in meteorites have isotopic anomalies which suggest that the grains were put together in a stellar explosion such as a supernova. Computer simulations allow such anomalies to be used to probe how these events happen. The simulations are being independently tested by experiments with high-energy density lasers, These developments are beginning to provide a quantitative diagnostic of galactic evolution, and of the epoch of formation of the first stars and galaxies. C1 LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94551 USA. RP Arnett, D (reprint author), UNIV ARIZONA, STEWARD OBSERV, TUCSON, AZ 85721 USA. NR 86 TC 13 Z9 13 U1 0 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAY 30 PY 1997 VL 276 IS 5317 BP 1359 EP 1362 DI 10.1126/science.276.5317.1359 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XB533 UT WOS:A1997XB53300035 PM 9161994 ER PT J AU Moss, WC Clarke, DB Young, DA AF Moss, WC Clarke, DB Young, DA TI Calculated pulse widths and spectra of a single sonoluminescing bubble SO SCIENCE LA English DT Article ID SYNCHRONOUS PICOSECOND SONOLUMINESCENCE AB A sonoluminescing bubble has been modeled as a thermally conducting, partially ionized, two-component plasma. The model shows that the measured picosecond pulse widths are due to electron conduction and the rapidly changing opacity of the plasma and that these mechanisms are also responsible for the absence of an ''afterglow'' subsequent to the sonoluminescence flash while the hot bubble expands and cools. The calculated spectra for sonoluminescing nitrogen and argon bubbles suggest that a sonoluminescing air bubble probably contains only argon, in agreement with a recent theoretical analysis. RP Moss, WC (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 26 TC 139 Z9 144 U1 1 U2 8 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 30 PY 1997 VL 276 IS 5317 BP 1398 EP 1401 DI 10.1126/science.276.5317.1398 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA XB533 UT WOS:A1997XB53300044 ER PT J AU Kuo, SC Zhang, ZY Ross, SK Klemm, RB Johnson, RD Monks, PS Thorn, RP Stief, LJ AF Kuo, SC Zhang, ZY Ross, SK Klemm, RB Johnson, RD Monks, PS Thorn, RP Stief, LJ TI Discharge flow-photoionization mass spectrometric study of HNO: Photoionization efficiency spectrum and ionization energy and proton affinity of NO SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID KINETIC DATA-BASE; AB-INITIO; HIGH-RESOLUTION; PHOTOELECTRON-SPECTROSCOPY; ELECTRONIC STATES; COUPLED-CLUSTER; SURFACES; RADICALS; THERMOCHEMISTRY; ISOMERIZATION AB Photoionization efficiency (PIE) spectra of HNO were measured over the wavelength range lambda = 110-125 nm and in the ionization threshold region, lambda = 118-124 nm, using a discharge flow-photoionization mass spectometer (DF-PIMS) apparatus coupled to a synchrotron radiation source. HNO was generated in situ by the following reaction sequence: N + NO --> N-2 + O; O + C2H4 --> CH3 + HCO; HCO + NO --> HNO + CO. The PIE spectrum displays steplike behavior near threshold and an HN-O stretching frequency in the cation of 1972 +/- 67 cm(-1). A value of 10.18(4) +/- 0.01(2) eV for the adiabatic ionization energy (IE) of HNO was obtained from photoionization thresholds, which correspond to the HNO+(X(2)A') <-- HNO(X(1)A') transition. This result is the first PIMS determination of IE(HNO). Also, an ab initio molecular orbital calculation (QCISD(T)/aug-cc-pVQZ) was performed that yields a value for IE(HNO) of 10.186 +/- 0.050 eV, There is good agreement between the experimental and the theoretical values for IE(HNO) reported here and that from a recent photoelectron spectroscopy study. The present experimental value for IE(HNO) was employed along with other, known thermodynamic quantities to obtain values for the heat of formation of the HNO cation and the absolute proton affinity of NO: Delta(f)H degrees(298)(HNO+) = 1089.73 +/- 1.18 kJ mol(-1) (Delta(f)H degrees(0)(HNO+) = 1092.65 +/- 1.18 kJ mol(-1)); PA(298)(NO) = 531.55 +/- 1.26 kJ mol(-1) (PA(0)(NO) = 526.12 +/- 1.26 kJ mol(-1)). C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NATL INST STAND & TECHNOL,DIV PHYS & CHEM PROPERTIES,GAITHERSBURG,MD 20899. NASA,GODDARD SPACE FLIGHT CTR,EXTRATERR PHYS LAB,GREENBELT,MD 20771. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 77 TC 16 Z9 16 U1 1 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 MAY 29 PY 1997 VL 101 IS 22 BP 4035 EP 4041 DI 10.1021/jp9705941 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XB799 UT WOS:A1997XB79900007 ER PT J AU Grifols, JA Mohapatra, RN Riotto, A AF Grifols, JA Mohapatra, RN Riotto, A TI Astrophysical bounds on superlight gravitinos SO PHYSICS LETTERS B LA English DT Article ID DYNAMICAL SUPERSYMMETRY BREAKING; LIGHT GRAVITINO; NEUTRINO BURST; CONSTRAINTS; STARS; MASS AB We derive the allowed mass range for the superlight gravitino present in a large class of supersymmetric models from the observed neutrino luminosity from Supernova 1987A. We find that for photino masses of order of 100 GeV, the mass range 2.6 x 10(-8) eV less than or equal to mg < 2.2 x 10(-6) eV for the gravitino (g) over tilde is excluded by SN1987A observations, Unlike the bounds on mg from nucleosynthesis, the bounds in the present paper do not depend critically upon the uncertainties of the observational input. (C) 1997 Elsevier Science B.V. C1 UNIV AUTONOMA BARCELONA,IFAE,BELLATERRA 08193,SPAIN. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Grifols, JA (reprint author), UNIV AUTONOMA BARCELONA,FIS TEOR GRP,BELLATERRA 08193,SPAIN. NR 28 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 29 PY 1997 VL 401 IS 3-4 BP 283 EP 286 DI 10.1016/S0370-2693(97)00394-8 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XC550 UT WOS:A1997XC55000014 ER PT J AU Wang, HX Peng, G Miller, LM Scheuring, EM George, SJ Chance, MR Cramer, SP AF Wang, HX Peng, G Miller, LM Scheuring, EM George, SJ Chance, MR Cramer, SP TI Iron L-edge X-ray absorption spectroscopy of myoglobin complexes and photolysis products SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID ELECTRON-PARAMAGNETIC RESONANCE; TRANSITION-METAL COMPOUNDS; CARBON-MONOXIDE MYOGLOBIN; HEME-PROTEINS; FLUORESCENCE YIELD; LIGAND-BINDING; RAMAN-SPECTRA; SPERM WHALE; HEMOGLOBIN; RESOLUTION AB We demonstrate the first application of L-edge X-ray absorption spectroscopy (XAS) to the electronic characterization of biological photolysis products. The experimental L-edge XAS spectra of deoxymyoglobin (deoxy Mb), oxymyoglobin (MbO(2)), carbonmonoxymyoglobin (MbCO), and the low-temperature photoproducts (Mb*CO and Mb*O-2) are presented and compared to simulated spectra using a ligand field multiplet calculation. This analysis indicates that MbCO and MbO(2) are both low spin and does not support some previous studies which suggest that MbO(2) has an intermediate spin. Both photoproducts, Mb*CO and Mb*O-2, are different from deoxy Mb in the Fe-II electronic structure. In addition, different low-temperature photolysis intermediates are suggested for MbCO and MbO(2). The L-edge XAS spectra for Fe-III in aquometmyoglobin (met Mb) and azidomet myoglobin (MbN(3)) provide a comparison of the ferrous versus ferric myoglobin species. Finally, the special advantages of using soft X-ray absorption spectroscopy for understanding the electronic transitions coupled to photolysis-induced structural changes are discussed. C1 YESHIVA UNIV ALBERT EINSTEIN COLL MED,DEPT PHYSIOL & BIOPHYS,BRONX,NY 10461. LAWRENCE BERKELEY NATL LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT APPL SCI,DAVIS,CA 95616. NR 64 TC 49 Z9 49 U1 3 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 MAY 28 PY 1997 VL 119 IS 21 BP 4921 EP 4928 DI 10.1021/ja961446b PG 8 WC Chemistry, Multidisciplinary SC Chemistry GA XB674 UT WOS:A1997XB67400014 ER PT J AU Rye, RR Nelson, GC Dugger, MT AF Rye, RR Nelson, GC Dugger, MT TI Mechanistic aspects of alkylchlorosilane coupling reactions SO LANGMUIR LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; SINGLE-CRYSTAL; SILICA; SURFACE; OCTADECYLTRICHLOROSILANE; FRICTION; WEAR AB Toluene solutions of monochlorosilane and trichlorosilane coupling agents are shown to react differently with hydrated and dry silicon surfaces. For typical hydrated surfaces produced by piranha (H2O2 + H2SO4) etching, the saturation coverages of octadecyldimethylchlorosilane (ODMS) (one reactive Si-O bond)are approximately a third that of octadecyltrichlorosilane (ODTS) (three reactive Si-O bonds). In contrast, for samples vacuum baked at 400 degrees C, the saturation coverages of ODTS and ODMS are comparable. These data are consistent with coupling reactions limited to the surface hydroxyl groups. The ODTS saturation coverage on vacuum-fired silicon samples can be increased by soaking in water followed by a second ODTS exposure. From X-ray photoelectron spectra (XPS) and secondary ion mass spectra (SIMS) obtained as a function of solution exposure time, saturation coverage is shown to take at least 2 h and to be limited by the concentration of surface hydroxyl groups; a direct correlation is seen in SIMS between the exposure dependent gain in the surface alkyl signal and the loss of the SiOH signal. The coefficient of friction of silicon (piranha etched is reduced by an order of magnitude by saturation coverages of ODTS, but continued rubbing for over 50 cycles at a normal loading of 245 mN results in decay of the friction coefficient to the value appropriate for uncoated silicon. These results as well as others from the literature are discussed in this paper in terms of a mechanism for the reaction of alkylchlorosilanes with silicon. C1 SANDIA NATL LABS, DEPT 1832MS0340, ALBUQUERQUE, NM 87185 USA. NR 18 TC 100 Z9 101 U1 0 U2 22 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 28 PY 1997 VL 13 IS 11 BP 2965 EP 2972 DI 10.1021/la960919p PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA XB656 UT WOS:A1997XB65600010 ER PT J AU Alam, M Peebles, DE Tallant, DR AF Alam, M Peebles, DE Tallant, DR TI Diamond deposition onto WC-6%Co cutting tool material: Coating structure and interfacial bond strength SO THIN SOLID FILMS LA English DT Article DE adhesion; carbides; diamond; field ion microscopy; Raman scattering ID CHEMICAL-VAPOR-DEPOSITION; CEMENTED TUNGSTEN CARBIDE; FILMS; ADHESION; GROWTH; SUBSTRATE; PHASE AB Diamond coatings were grown on WC-6%Co cutting tool material. Measurements were carried out to investigate the effects of diamond seeding of the substrate before deposition, removal of cobalt from the substrate before deposition, and boron incorporation into the coating during growth on the growth rate, morphology and structure of the coating, and coating-substrate adhesion. Diamond seeding of the substrate resulted in a higher growth rate and diamond fraction of the coating relative to a polished and unseeded surface. Etching of cobalt from the substrate resulted in a higher growth rate, diamond fraction and adhesion strength relative to the unetched surface. Introduction of methanol into the gas phase led to a lower growth rate, diamond fraction and adhesion strength relative to the case when no methanol was injected. Introduction of boron oxide (B2O3) along with methanol into the gas phase did not affect the growth rate but increased both the diamond fraction and adhesion strength relative to the case when only methanol was added. It is believed that adhesion failure occurs at the diamond-substrate interface, possibly within a soft nanocrystalline graphite transition layer. (C) 1997 Published by Elsevier Science S.A. C1 SANDIA NATL LABS, ALBUQUERQUE, NM 87185 USA. RP NEW MEXICO INST MIN & TECHNOL, DEPT MAT ENGN, SOCORRO, NM 87801 USA. NR 24 TC 20 Z9 22 U1 0 U2 2 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 28 PY 1997 VL 300 IS 1-2 BP 164 EP 170 DI 10.1016/S0040-6090(96)09467-9 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XH763 UT WOS:A1997XH76300025 ER PT J AU Blum, O Ashby, CIH Hou, HQ AF Blum, O Ashby, CIH Hou, HQ TI Barrier-layer-thickness control of selective wet oxidation of AlGaAs for embedded optical elements SO APPLIED PHYSICS LETTERS LA English DT Article ID VERTICAL-CAVITY LASERS; GAAS AB Selective wet oxidation of AlGaAs layers can be used to form embedded optical elements, such as buried lenses and current control apertures in vertical cavity structures, Oxidation rates of buried Al0.94Ga0.06As layers were controlled by varying the thickness of GaAs barrier layers between layers of Al0.94Ga0.06As and Al0.98Ga0.02As. This phenomenon can be attributed to the superposition of a vertical oxidation component due to species diffusing through the barrier layer and a constant lateral oxidation component. The magnitude of the vertical component is controlled by the GaAs barrier thickness. which determines the concentration of additional oxidizing species in the Al0.94Ga0.06As layer. (C) 1997 American Institute of Physics. RP Blum, O (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 26 PY 1997 VL 70 IS 21 BP 2870 EP 2872 DI 10.1063/1.119028 PG 3 WC Physics, Applied SC Physics GA XA599 UT WOS:A1997XA59900031 ER PT J AU Blocki, J Skalski, J Swiatecki, WJ AF Blocki, J Skalski, J Swiatecki, WJ TI The excitation of an independent particle gas by a time-dependent potential well .2. SO NUCLEAR PHYSICS A LA English DT Article DE one-body dissipation; chaos vs order; nuclear ID DISSIPATION AB A systematic comparison is carried out between quantal and classical computer simulations of the excitation of independent particles in a time-dependent potential well undergoing one cycle of oscillation. Eleven values of the diffuseness, up to 25 values of the oscillation frequency, and five Legendre polynomial deformations P-2, P-3, P-4, P-5, P-6 were examined. Oscillations around the spherical shape as well as around a P-3 deformed shape were considered. The results are compared with the one-body dissipation theory in the form of the wall formula, including corrections for the heating up of the gas, the diffuseness of the surface, the wave-mechanical suppression of dissipation and the reduction in the effective volume available to a quantal gas in a container whose diffuseness is small compared to the particle wavelengths. (C) 1997 Published by Elsevier Science B.V. C1 INST NUCL STUDIES,PL-00681 WARSAW,POLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Blocki, J (reprint author), INST NUCL STUDIES,PL-05400 OTWOCK,POLAND. NR 11 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 26 PY 1997 VL 618 IS 1-2 BP 1 EP 19 DI 10.1016/S0375-9474(97)00017-1 PG 19 WC Physics, Nuclear SC Physics GA XB739 UT WOS:A1997XB73900001 ER PT J AU Ormand, WE Bortignon, PF Broglia, RA AF Ormand, WE Bortignon, PF Broglia, RA TI Effects of angular momentum projection on the nuclear partition function and the observation of the giant-dipole resonance in hot nuclei SO NUCLEAR PHYSICS A LA English DT Article ID ROTATING NUCLEI; THERMAL FLUCTUATIONS; APPROXIMATION AB Procedures for projecting the angular momentum in a model describing a hot nucleus that takes into account large-amplitude quadrupole fluctuations are discussed, Particular attention is paid to the effect angular momentum projection has on the observables associated with the gamma-decay of the giant-dipole resonance (GDR),We also elaborate on which of the different projection methods provides the best overall description of the GDR, including angular distributions, The main consequence of angular momentum projection is the appearance of an effective volume element in the integrals associated with the thermal average of the physical observables, This effective volume element is controlled by the value of the moments of inertia of the system, In the limit of rigid-body moments of inertia, the effective volume element is found to differ only slightly from the volume element associated with the normalization of the five-dimensional quadrupole oscillator wavefunction in the beta, gamma, and Omega space, namely D[alpha] = beta(4)d beta sin(3 gamma) d gamma d Omega. In the limit of irrotational flow moments of inertia, the leading behavior in the beta degree of freedom is D[alpha] proportional to beta d beta. (C) 1997 Published by Elsevier Science B.V. C1 IST NAZL FIS NUCL,I-20133 MILAN,ITALY. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. LOUISIANA STATE UNIV,DEPT PHYS & ASTRON,BATON ROUGE,LA 70803. 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 24 TC 22 Z9 22 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 26 PY 1997 VL 618 IS 1-2 BP 20 EP 34 DI 10.1016/S0375-9474(97)00027-4 PG 15 WC Physics, Nuclear SC Physics GA XB739 UT WOS:A1997XB73900002 ER PT J AU Pichler, R Oberhummer, H Csoto, A Moszkowski, SA AF Pichler, R Oberhummer, H Csoto, A Moszkowski, SA TI Three-alpha structures in C-12 SO NUCLEAR PHYSICS A LA English DT Article DE C-12 states; three-body resonances; few-body dynamics; three-alpha model; cluster model ID NEUTRON HALO NUCLEI; DIPOLE MODE PROBLEM; 3-BODY RESONANCES; EXCITED-STATES; HE-6; LI-6; HAMILTONIANS; BINDING; ENERGY; BE-6 AB We search for three-alpha resonances in C-12 by using the complex scaling method in a microscopic cluster model. All experimentally known low-lying natural-parity states of C-12 are localized. For the first time we unambiguously show in a microscopic model that the O-2(+) state in C-12, which plays an important role in stellar nucleosynthesis, is a genuine three-alpha resonance. (C) 1997 Elsevier Science B.V. C1 LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. UNIV CALIF LOS ANGELES, DEPT PHYS, LOS ANGELES, CA 90095 USA. RP VIENNA TECH UNIV, INST KERNPHYS, WIEDNER HAUPTSTR 8-10, A-1040 VIENNA, AUSTRIA. NR 51 TC 38 Z9 38 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 26 PY 1997 VL 618 IS 1-2 BP 55 EP 64 PG 10 WC Physics, Nuclear SC Physics GA XB739 UT WOS:A1997XB73900004 ER PT J AU Barbieri, R Hall, LJ Raby, S Romanino, A AF Barbieri, R Hall, LJ Raby, S Romanino, A TI Unified theories with U(2) flavor symmetry SO NUCLEAR PHYSICS B LA English DT Article DE flavor symmetries; unification; fermion masses and mixings ID MASS MATRIX MODELS; SUPERSYMMETRIC TECHNICOLOR; HORIZONTAL SYMMETRY; FERMION MASSES; TOP-QUARK; UNIFICATION; GAUGE; PREDICTIONS; HIERARCHY; BREAKING AB A general operator expansion is presented for quark and lepton mass matrices in unified theories based on a U(2) flavor symmetry, with breaking parameter of order V-cb approximate to m(s)/m(b) approximate to root m(c)/m(t). While solving the supersymmetric flavor-changing problem, a general form for the Yukawa couplings follows, leading to nine relations among the fermion masses and mixings, five of which are precise. The combination of grand unified and U(2) symmetries provides a symmetry understanding for the anomalously small values of m(u)/m(c) and m(c)/m(t). A fit to the fermion mass data leads to a prediction for the angles of the CKM unitarity triangle, which will allow a significant test of these unified U(2) theories. A particular SO(10) model provides a simple realization of the general operator expansion. The lighter generation masses and the non-trivial structure of the CKM matrix are generated from the exchange of a single U(2) doublet of heavy vector generations. This model suggests that CP is spontaneously broken at the unification scale-in which case there is a further reduction in the number of free parameters. (C) 1997 Elsevier Science B.V. C1 UNIV PISA,DEPT PHYS,I-56126 PISA,ITALY. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. OHIO STATE UNIV,DEPT PHYS,COLUMBUS,OH 43210. IST NAZL FIS NUCL,SEZ PISA,I-56126 PISA,ITALY. RP Barbieri, R (reprint author), UNIV PISA,DEPT PHYS,I-56126 PISA,ITALY. RI Romanino, Andrea/I-3480-2012 OI Romanino, Andrea/0000-0002-5915-4747 NR 57 TC 181 Z9 181 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 26 PY 1997 VL 493 IS 1-2 BP 3 EP 26 DI 10.1016/S0550-3213(97)00134-X PG 24 WC Physics, Particles & Fields SC Physics GA XB187 UT WOS:A1997XB18700001 ER PT J AU Binetruy, P Gaillard, MK Wu, YY AF Binetruy, P Gaillard, MK Wu, YY TI Modular invariant formulation of multi-gaugino and matter condensation SO NUCLEAR PHYSICS B LA English DT Article DE modular invariance; linear multiplet; multi-gaugino condensation ID EFFECTIVE LAGRANGIAN ANALYSIS; SUPERSYMMETRY BREAKING; STRING THEORY; SUPERSPACE GEOMETRY; SUPERSTRING MODELS; COUPLING-CONSTANT; LOOP CORRECTIONS; 4 DIMENSIONS; UNIFICATION; DUALITY AB Using the linear multiplet formulation for the dilaton superfield, we construct an effective Lagrangian for hidden sector gaugino condensation in string effective field theories with arbitrary gauge groups and matter. Non-perturbative string corrections to the Kahler potential are invoked to stabilize the dilaton at a supersymmetry breaking minimum of the potential. When the cosmological constant is tuned to zero the moduli are stabilized at their self-dual points, and the vevs of their F-component superpartners vanish. Numerical analyses of one- and two-condensate examples with massless chiral matter show considerable enhancement of the gauge hierarchy with respect to the E-8 case. The non-perturbative string effects required for dilaton stabilization may have implications for gauge coupling unification. As a comparison, we also consider a parallel approach based on the commonly used chiral formulation. (C) 1997 Elsevier Science B.V. C1 UNIV PARIS 11,PHYS THEOR & HAUTES ENERGIES LAB,CNRS,URA D0063,F-91405 ORSAY,FRANCE. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP 50A 5101,BERKELEY,CA 94720. RP Binetruy, P (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 59 TC 95 Z9 95 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 26 PY 1997 VL 493 IS 1-2 BP 27 EP 55 DI 10.1016/S0550-3213(97)00162-4 PG 29 WC Physics, Particles & Fields SC Physics GA XB187 UT WOS:A1997XB18700002 ER PT J AU deBoer, J Hori, K Ooguri, H Oz, Y AF deBoer, J Hori, K Ooguri, H Oz, Y TI Mirror symmetry in three-dimensional gauge theories, quivers and D-branes SO NUCLEAR PHYSICS B LA English DT Article ID ALE SPACES; INSTANTONS AB We construct and analyze dual N = 4 supersymmetric gauge theories in three dimensions with unitary and symplectic gauge groups. The gauge groups and the field content of the theories are encoded in quiver diagrams. The duality exchanges the Coulomb and Higgs branches and the Fayet-Iliopoulos and mass parameters. We analyze the classical and the quantum moduli spaces of the theories and construct an explicit mirror map between the mass parameters and the Fayet-Iliopoulos parameters of the dual. The results generalize the relation between ALE spaces and moduli spaces of SU(n) and SO(2n) instantons. We interpret some of these results from the string theory viewpoint, for SU(n) by analyzing T-duality and extremal transitions in type II string compactifications, for SO(2n) by using D-branes as probes. Finally, we make a proposal for the moduli space of vacua of these theories in the absence of matter. (C) 1997 Elsevier Science B.V. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP deBoer, J (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,366 LE CONTE HALL,BERKELEY,CA 94720, USA. RI Ooguri, Hirosi/A-4407-2011; OI Ooguri, Hirosi/0000-0001-6021-3778 NR 40 TC 98 Z9 98 U1 1 U2 1 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 MAY 26 PY 1997 VL 493 IS 1-2 BP 101 EP 147 DI 10.1016/S0550-3213(97)00125-9 PG 47 WC Physics, Particles & Fields SC Physics GA XB187 UT WOS:A1997XB18700005 ER PT J AU deBoer, J Hori, K Ooguri, H Oz, Y Yin, Z AF deBoer, J Hori, K Ooguri, H Oz, Y Yin, Z TI Mirror symmetry in three-dimensional gauge theories, SL(2,Z) and D-brane moduli spaces SO NUCLEAR PHYSICS B LA English DT Article ID ALE SPACES; INSTANTONS; DUALITY AB We construct intersecting D-brane configurations that encode the gauge groups and field content of dual N = 4 supersymmetric gauge theories in three dimensions. The duality which exchanges the Coulomb and Higgs branches and the Fayet-Iliopoulos and mass parameters is derived from the SL(2,Z) symmetry of the type IIB string. Using the D-brane configurations we construct explicitly this mirror map between the dual theories and study the instanton corrections in the D-brane world-volume theory via open string instantons. A general procedure to obtain mirror pairs is presented and illustrated. We encounter transitions among different field theories that correspond to smooth movements in the D-brane moduli space. We discuss the relation between the duality of the gauge theories and the level-rank duality of affine Lie algebras. Examples of other dual theories are presented and explained via T-duality and extremal transitions in type II string compactifications. Finally we discuss a second way to study instanton corrections in the gauge theory, by wrapping 5-branes around six-cycles in M-theory compactified on a Calabi-Yau 4-fold. (C) 1997 Elsevier Science B.V. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP deBoer, J (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,366 LE CONTE HALL,BERKELEY,CA 94720, USA. RI Ooguri, Hirosi/A-4407-2011 NR 33 TC 80 Z9 80 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 26 PY 1997 VL 493 IS 1-2 BP 148 EP 176 DI 10.1016/S0550-3213(97)00115-6 PG 29 WC Physics, Particles & Fields SC Physics GA XB187 UT WOS:A1997XB18700006 ER PT J AU Coriano, C White, AR Wusthoff, M AF Coriano, C White, AR Wusthoff, M TI NLO conformal symmetry in the Regge limit of QCD SO NUCLEAR PHYSICS B LA English DT Article DE BFKL; Pomeron; conformal symmetry; higher orders ID LIPATOV KERNEL; O(G(4)) AB We show that a scale-invariant approximation to the next-to-leading-order BFKL kernel, constructed via transverse momentum diagrams, has a simple conformally invariant representation in impact parameter space, i.e. [GRAPHICS] That a conformally invariant representation exists is shown first by relating the kernel directly to Feynman diagrams contributing to two-photon diffractive dissociation. (C) 1997 Elsevier Science B.V. C1 UNIV FLORIDA,INST FUNDAMENTAL THEORY,DEPT PHYS,GAINESVILLE,FL 32611. RP Coriano, C (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,9700 S CASS,ARGONNE,IL 60439, USA. OI Coriano', Claudio/0000-0003-0479-8075 NR 12 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 26 PY 1997 VL 493 IS 1-2 BP 397 EP 410 DI 10.1016/S0550-3213(97)00137-5 PG 14 WC Physics, Particles & Fields SC Physics GA XB187 UT WOS:A1997XB18700014 ER PT J AU Bravar, A Adams, DL Akchurin, N Belikov, NI Bonner, BE Bystricky, J Corcoran, MD Cossairt, JD Cranshaw, J Derevschikov, AA Enyo, H Funahashi, H Goto, Y Grachov, OA Grosnick, DP Hill, DA Iijima, T Imai, K Itow, Y Iwatani, K Kuroda, K Laghai, M Lehar, F deLesquen, A Lopiano, D Luehring, FC Maki, T Makino, S Masaike, A Matulenko, YA Meschanin, AP Michalowicz, A Miller, DH Miyake, K Nagamine, T NessiTedaldi, F Nessi, M Nguyen, C Nurushev, SB Ohashi, Y Onel, Y Patalakha, DI Pauletta, G Penzo, A Rappazzo, GF Read, AL Roberts, JB vanRossum, L Rykov, VL Saito, N Salvato, G Schiavon, P Skeens, J Solovyanov, VL Spinka, H Stanek, RW Takashima, R Takeutchi, F Tamura, N Underwood, DG Vasiliev, AN White, JL Yamashita, S Yokosawa, A Yoshida, T Zanetti, AM AF Bravar, A Adams, DL Akchurin, N Belikov, NI Bonner, BE Bystricky, J Corcoran, MD Cossairt, JD Cranshaw, J Derevschikov, AA Enyo, H Funahashi, H Goto, Y Grachov, OA Grosnick, DP Hill, DA Iijima, T Imai, K Itow, Y Iwatani, K Kuroda, K Laghai, M Lehar, F deLesquen, A Lopiano, D Luehring, FC Maki, T Makino, S Masaike, A Matulenko, YA Meschanin, AP Michalowicz, A Miller, DH Miyake, K Nagamine, T NessiTedaldi, F Nessi, M Nguyen, C Nurushev, SB Ohashi, Y Onel, Y Patalakha, DI Pauletta, G Penzo, A Rappazzo, GF Read, AL Roberts, JB vanRossum, L Rykov, VL Saito, N Salvato, G Schiavon, P Skeens, J Solovyanov, VL Spinka, H Stanek, RW Takashima, R Takeutchi, F Tamura, N Underwood, DG Vasiliev, AN White, JL Yamashita, S Yokosawa, A Yoshida, T Zanetti, AM TI Spin transfer in inclusive Lambda(0) production by transversely polarized protons at 200 GeV/c SO PHYSICAL REVIEW LETTERS LA English DT Article ID HADRON-HADRON COLLISIONS; HYPERON POLARIZATION; ANALYZING POWER; HIGH-ENERGIES; ASYMMETRY; BEAM; MOMENT AB Surprisingly large polarizations in hyperon production by unpolarized protons have been known for a long time. The spin dynamics of the production process can be further investigated with polarized beams. Recently, a negative asymmetry A(N) was found in inclusive Lambda(0) production with a 200 GeV/c transversely polarized proton beam. The depolarization D-NN in p up arrow + p --> Lambda(0) + X has been measured with the same beam over a wide x(F) range and at moderate p(tau). D-NN reaches positive values of about 30% at high x(F) and p(T) similar to 1.0 Ge V/c. This result shows a sizable spin transfer from the incident polarized proton to the outgoing Lambda(0). C1 ARGONNE NATL LAB,ARGONNE,IL 60439. CENS,CEA,DAPNIA,SPP,F-91191 GIF SUR YVETTE,FRANCE. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. HIROSHIMA UNIV,HIGASHIHIROSHIMA 724,JAPAN. INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. UNIV IOWA,DEPT PHYS & ASTRON,IOWA CITY,IA 52242. UNIV OCCUPAT & ENVIRONM HLTH,KITAKYUSHU,FUKUOKA 807,JAPAN. KYOTO UNIV,DEPT PHYS,KYOTO 60601,JAPAN. KYOTO UNIV,KYOTO 612,JAPAN. KYOTO SANGYO UNIV,KYOTO 612,JAPAN. PHYS PARTICULES LAB,F-74017 ANNECY LE VIEUX,FRANCE. UNIV MESSINA,DIPARTIMENTO FIS,I-98100 MESSINA,ITALY. IST NAZL FIS NUCL,I-98100 MESSINA,ITALY. NORTHWESTERN UNIV,DEPT PHYS,EVANSTON,IL 60201. OKAYAMA UNIV,DEPT PHYS,OKAYAMA 800,JAPAN. OSAKA CITY UNIV,OSAKA 558,JAPAN. RICE UNIV,TW BONNER NUCL LAB,HOUSTON,TX 77251. UNIV TRIESTE,DIPARTIMENTO FIS,I-34100 TRIESTE,ITALY. IST NAZL FIS NUCL,I-34100 TRIESTE,ITALY. UNIV UDINE,I-33100 UDINE,ITALY. IST NAZL FIS NUCL,I-33100 UDINE,ITALY. NR 28 TC 34 Z9 34 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 26 PY 1997 VL 78 IS 21 BP 4003 EP 4006 DI 10.1103/PhysRevLett.78.4003 PG 4 WC Physics, Multidisciplinary SC Physics GA XA465 UT WOS:A1997XA46500006 ER PT J AU Ihra, W Macek, JH MotaFurtado, F OMahony, PF AF Ihra, W Macek, JH MotaFurtado, F OMahony, PF TI Threshold law for positron impact ionization of atoms SO PHYSICAL REVIEW LETTERS LA English DT Article ID BEHAVIOR AB We demonstrate that recent experiments for positron impact ionization of He and H-2 can be interpreted by extending Wannier theory to higher energies. Anharmonicities-in the expansion of the three-particle potential around the Wannier configuration give rise to corrections in the threshold behavior of the breakup cross section. These corrections are taken into account perturbatively by employing the hidden crossing theory. The resulting threshold law is sigma(E) proportional to E-2.640 exp[-0.73 root E]. The actual energy range for which the Wannier law is valid is found to be smaller for positron impact ionization than for electron impact ionization. C1 UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Ihra, W (reprint author), UNIV LONDON,ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT MATH,EGHAM TW20 0EX,SURREY,ENGLAND. NR 18 TC 27 Z9 27 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 26 PY 1997 VL 78 IS 21 BP 4027 EP 4030 DI 10.1103/PhysRevLett.78.4027 PG 4 WC Physics, Multidisciplinary SC Physics GA XA465 UT WOS:A1997XA46500012 ER PT J AU Zhang, SB Wei, SH Zunger, A AF Zhang, SB Wei, SH Zunger, A TI Stabilization of ternary compounds via ordered arrays of defect pairs SO PHYSICAL REVIEW LETTERS LA English DT Article ID FORMATION ENERGIES; GAAS AB First-principles calculations show that the defect pair (2V(Cu)(-) + In-Cu(+)) in CuInSe2 has an unusually low formation energy, due both to the relative ease of forming Cu vacancies (V-Cu) and to the attractive interactions between V(Cu)(-) and In-Cu(2+). The defect pair is predicted to be electrically inactive. This explains the surprising electrical tolerance of CuInSe2 to its huge (similar to 1%) concentration of native defects. An attractive interaction among the defect pairs is further predicted to lead to a crystallographic ordering of the pairs, explaining the observed, but hitherto surprising, structures CuIn5Se8, CuIn3Se5, Cu2In4Se7, etc. RP Zhang, SB (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013; Krausnick, Jennifer/D-6291-2013; Zhang, Shengbai/D-4885-2013 OI Zhang, Shengbai/0000-0003-0833-5860 NR 12 TC 207 Z9 215 U1 6 U2 26 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 26 PY 1997 VL 78 IS 21 BP 4059 EP 4062 DI 10.1103/PhysRevLett.78.4059 PG 4 WC Physics, Multidisciplinary SC Physics GA XA465 UT WOS:A1997XA46500020 ER PT J AU Narayanan, PK Rudnick, JM Walthers, EA Crissman, HA AF Narayanan, PK Rudnick, JM Walthers, EA Crissman, HA TI Modulation in cell cycle and cyclin B1 expression in irradiated HeLa cells and normal human skin fibroblasts treated with staurosporine and caffeine SO EXPERIMENTAL CELL RESEARCH LA English DT Article ID CHINESE-HAMSTER OVARY; IONIZING-RADIATION; MESSENGER-RNA; G(2)-PHASE ARREST; MAMMALIAN-CELLS; FLOW-CYTOMETRY; DNA-SYNTHESIS; G2 ARREST; S3 CELLS; P34CDC2 AB The comparative effects of staurosporine or caffeine on G(2)-phase arrest and cyclin B1 expression in human skin fibroblasts (HSF) and transformed HeLa cells following gamma-irradiation were examined by flow cytometry. Contrary to some earlier reports with HeLa cells, the arrest in G(2) after irradiation was accompanied by an increase in cyclin B1 levels in both asynchronous and synchronized HeLa cells irradiated in early S phase. Caffeine and staurosporine were equally effective in attenuating both the radiation-induced increase in cyclin B1 expression and the prolongation of G(2) in synchronous and asynchronous HeLa cell populations. Staurosporine treatment was less effective in down-regulating cyclin B1 expression in asynchronous HeLa cells at earlier time points following irradiation when compared to caffeine-treated cells. In synchronized HeLa cells, down-regulation of an irradiation-induced increase in cyclin B1 expression was similar to either staurosporine or caffeine treatments, with caffeine being more effective at later time points. An increase in cyclin B1 expression was also observed in irradiated HSF cells (synchronous and asynchronous), which decreased when the cells were treated with staurosporine or caffeine. However, staurosporine was ineffective in attenuating the radiation-induced prolongation of G(2) in synchronous and asynchronous HSF cells, whereas treatment of irradiated synchronous or asynchronous HSF cells with caffeine significantly reduced the prolongation of G(2). These results suggest that both staurosporine and caffeine treatments act on different pathways of cell cycle control in normal and transformed cells, in terms of attenuation of G(2) block and diminution of elevated levels of cyclin B1 expression, in response to radiation. (C) 1997 Academic Press. C1 LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. NR 36 TC 22 Z9 23 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 0014-4827 J9 EXP CELL RES JI Exp. Cell Res. PD MAY 25 PY 1997 VL 233 IS 1 BP 118 EP 127 DI 10.1006/excr.1997.3549 PG 10 WC Oncology; Cell Biology SC Oncology; Cell Biology GA XC182 UT WOS:A1997XC18200013 PM 9184081 ER PT J AU Chen, LX Laible, PD AF Chen, LX Laible, PD TI Third order nonlinear optical properties of bacteriochlorophylls in bacterial photosynthetic light-harvesting proteins SO CHEMICAL PHYSICS LETTERS LA English DT Article ID RHODOPSEUDOMONAS-SPHAEROIDES; RHODOBACTER-SPHAEROIDES; EXCITED-STATE; COMPLEX; DYNAMICS AB The third order hyperpolarizability, [gamma], of the ground state S-0 of bacteriochlorophyll a (BChla) has been determined using degenerate four wave mixing. The [gamma] for BChla in vivo (the B875 and B850 arrays of light harvesting proteins) is enhanced relative to that in vitro (THF). A significantly higher [gamma] in B875 than that in B850 suggests stronger pigment interactions in the former resulting from superior overlap of adjacent macrocycles. In addition, a 50-160 fold increase in [gamma] for the S-1 excited state of relative to S-0 of BChla in vivo provides an alternative method for probing excited state dynamics and a potential application for molecular switching. RP Chen, LX (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 30 TC 12 Z9 12 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 MAY 23 PY 1997 VL 270 IS 3-4 BP 255 EP 262 DI 10.1016/S0009-2614(97)00373-4 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA804 UT WOS:A1997XA80400001 ER PT J AU Labouriau, A Earl, WL AF Labouriau, A Earl, WL TI Titanium solid-state NMR in anatase, brookite and rutile SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SPECTROSCOPY; CRYSTALS; BATIO3; XANES; TI-49; FIELD; TI AB We report Ti-47 and Ti-49 NMR spectra of powdered samples of the three common phases of titania, TiO2. The linewidths are dominated by the electric quadrupole interaction. The relative linewidths of the three samples cannot be explained in terms of simple structural symmetry using point charges. This indicates that a significant amount of the Ti-O interaction is covalent in nature. RP Labouriau, A (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MAIL STOP J514,LOS ALAMOS,NM 87545, USA. NR 21 TC 28 Z9 28 U1 3 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 23 PY 1997 VL 270 IS 3-4 BP 278 EP 284 DI 10.1016/S0009-2614(97)00374-6 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA804 UT WOS:A1997XA80400005 ER PT J AU Deng, L Garrett, WR Payne, MG Moore, MA AF Deng, L Garrett, WR Payne, MG Moore, MA TI Gain suppression involving both stimulated Raman and hyper-Raman photons in two-step stimulated emissions SO CHEMICAL PHYSICS LETTERS LA English DT Article ID DEPENDENT QUANTUM INTERFERENCE; MULTIPHOTON IONIZATION; 3-PHOTON RESONANCE; XE; GENERATION; SCATTERING; SHIFTS AB We show that multiphoton destructive interference leading to gain suppression can be produced even when two different step-wise stimulated emissions, such as stimulated Raman and hyper-Raman emissions, are included in the interference loop. (C) 1997 Published by Elsevier Science B,V. C1 OAK RIDGE NATL LAB,CHEM PHYS SECT,OAK RIDGE,TN 37831. ST JOSEPHS UNIV,DEPT PHYS,PHILADELPHIA,PA 19131. RP Deng, L (reprint author), GEORGIA SO UNIV,DEPT PHYS,STATESBORO,GA 30360, USA. RI Deng, Lu/B-3997-2012 NR 21 TC 5 Z9 5 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 MAY 23 PY 1997 VL 270 IS 3-4 BP 299 EP 303 DI 10.1016/S0009-2614(97)00371-0 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA804 UT WOS:A1997XA80400008 ER PT J AU Taketsugu, T Gordon, MS AF Taketsugu, T Gordon, MS TI An ab initio study of the reaction mechanism of Co++NH3 SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID TRANSITION-METAL CARBENE; DEGENERATE PERTURBATION-THEORY; COMPACT EFFECTIVE POTENTIALS; EXPONENT BASIS-SETS; C BOND ACTIVATION; SPACE SCF METHOD; ELECTRONIC-STRUCTURE; GEOMETRIC STRUCTURES; HIGH-VALENT; GAS-PHASE AB To investigate the mechanism for N-H bond activation by a transition metal, the reactions of Co+(F-3,F-5) With NH3 have been studied with complete active space self-consistent field (CASSCF), multireference configuration interaction (MR-SDCI), and multireference many body perturbation theory (MRMP) wave functions, using both effective core potential and all-electron methods. Upon their initial approach, the reactants yield an ion-molecule complex, CoNH3+(E-3,(5)A(2),(5)A(1)), With retention of C-3v symmetry. The Co+=NH3 binding energies are estimated to be 49 (triplet) and 45 (quintet) kcal/mol. Subsequently, the N-H bond is activated, leading to an intermediate complex H-Co-NH2+ (C-2v symmetry), through a three-center transition state with an energy barrier of 56-60 (triplet) and 70-73 (quintet) kcal/mol. The energy of H-Co-NH2+, relative to that of CoNH3+, is estimated to be 60 to 61 (triplet) and 44 (quintet) kcal/mol. However, the highest levels of theory employed here (including dynamic correlation corrections) suggest that the triplet intermediate HCoNH2+ may not exist as a minimum on the potential energy surface. Following Co-N or H-Co bond cleavage, the complex H-Co-NH2+ leads to HCo++NH2 or H+CoNH2+. Both channels (triplet and quintet) are found to be endothermic by 54-64 kcal/mol. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DEPT ENERGY,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,US DEPT ENERGY,AMES,IA 50011. RP Taketsugu, T (reprint author), UNIV TOKYO,DEPT APPL CHEM,GRAD SCH ENGN,BUNKYO KU,7-3-1 HONGO,TOKYO 113,JAPAN. RI Taketsugu, Tetsuya/A-4304-2012 NR 121 TC 18 Z9 18 U1 0 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 22 PY 1997 VL 106 IS 20 BP 8504 EP 8515 DI 10.1063/1.474058 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA XA041 UT WOS:A1997XA04100021 ER PT J AU CortinaGil, MD Roussel-Chomaz, P Alamanos, N Barrette, J Mittig, W Dietrich, FS Auger, F Blumenfeld, Y Casandjian, JM Chartier, M Fekou-Youmbi, V Fernandez, B Frascaria, N Gillibert, A Laurent, H Lepine-Szily, A Orr, NA Scarpaci, JA Sida, JL Suomijarvi, T AF CortinaGil, MD Roussel-Chomaz, P Alamanos, N Barrette, J Mittig, W Dietrich, FS Auger, F Blumenfeld, Y Casandjian, JM Chartier, M Fekou-Youmbi, V Fernandez, B Frascaria, N Gillibert, A Laurent, H Lepine-Szily, A Orr, NA Scarpaci, JA Sida, JL Suomijarvi, T TI Proton elastic scattering on light neutron-rich nuclei SO PHYSICS LETTERS B LA English DT Article ID MICROSCOPIC OPTICAL-MODEL; ISOSPIN DEPENDENCE; ENERGY; LI-11 C1 GANIL, DSM CEA, IN2P3 CNRS, F-14021 CAEN, FRANCE. CEA, DSM DAPNIA SPhN SACLAY, F-91191 GIF SUR YVETTE, FRANCE. MC GILL UNIV, FOSTER RADIAT LAB, MONTREAL, PQ H3A 2B1, CANADA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. IPN, IN2P3 CNRS, F-91406 ORSAY, FRANCE. IFUSP, DFN, BR-05315970 SAO PAULO, SP, BRAZIL. LPC ISMRA, F-14050 CAEN, FRANCE. RP CortinaGil, MD (reprint author), GSI, POSTFACH 110552, D-64220 DARMSTADT, GERMANY. RI Lepine-Szily , Alinka/I-3325-2012; OI Lepine-Szily , Alinka/0000-0001-6640-8824; Cortina Gil, Dolores/0000-0001-7672-9912 NR 21 TC 48 Z9 50 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 22 PY 1997 VL 401 IS 1-2 BP 9 EP 14 DI 10.1016/S0370-2693(97)00321-3 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200002 ER PT J AU Halyo, E Kol, B Rajaraman, A Susskind, L AF Halyo, E Kol, B Rajaraman, A Susskind, L TI Counting Schwarzschild and charged black holes SO PHYSICS LETTERS B LA English DT Article AB We review the arguments that fundamental string states are in one to one correspondence with black hole states. We demonstrate the power of the assumption by showing that it implies that the statistical entropy of a wide class of nonextreme black holes occurring in string theory is proportional to the horizon area, However, the numerical coefficient relating the area and entropy only agrees with the Bekenstein-Hawking formula if the central charge of the string is six which does not correspond to any known string theory. Unlike the current D-brane methods the method used in this paper is applicable for the case of Schwarzschild and highly non-extreme charged black holes. (C) 1997 Published by Elsevier Science B.V. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94305. RP Halyo, E (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 15 TC 56 Z9 56 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 22 PY 1997 VL 401 IS 1-2 BP 15 EP 20 DI 10.1016/S0370-2693(97)00357-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200003 ER PT J AU Poppitz, E Trivedi, SP AF Poppitz, E Trivedi, SP TI Some remarks on gauge-mediated supersymmetry breaking SO PHYSICS LETTERS B LA English DT Article ID RENORMALIZATION-GROUP EQUATIONS; DIMENSIONAL REDUCTION; SUPERGRAPHS; REGULARIZATION; TECHNICOLOR AB We investigate the communication of supersymmetry breaking to the standard model in theories of gauge mediated supersymmetry breaking with general weakly coupled messenger sectors. We calculate the one-loop gaugino and two-loop soft scalar masses for nonvanishing Str M-2 of the messenger sector. The soft scalar masses are sensitive to physics at scales higher than the messenger scale, in contrast to models with vanishing messenger supertrace. We discuss the implications of this ultraviolet sensitivity in theories with renormalizable and nonrenormalizable supersymmetry breaking sectors. We note that the standard relation, in minimal gauge mediation, between soft scalar and gaugino masses is altered in models with nonvanishing messenger supertrace. (C) 1997 Elsevier Science B.V. C1 FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. RP UNIV CHICAGO, ENRICO FERMI INST, 5640 S ELLIS AVE, CHICAGO, IL 60637 USA. NR 44 TC 87 Z9 87 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 EI 1873-2445 J9 PHYS LETT B JI Phys. Lett. B PD MAY 22 PY 1997 VL 401 IS 1-2 BP 38 EP 46 DI 10.1016/S0370-2693(97)00367-5 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200006 ER PT J AU Barbieri, R Hall, LJ Romanino, A AF Barbieri, R Hall, LJ Romanino, A TI Consequences of a U(2) flavour symmetry SO PHYSICS LETTERS B LA English DT Article ID SUPERSYMMETRY; UNIFICATION; BREAKING AB While solving the supersymmetric flavour problem, a U(2) flavour symmetry might be at the origin of the pattern of fermion masses and mixings. The consequences of this hypothesis are spelled out concerning the parameters of the CKM matrix and their observability in B- and K-physics. The relevance of searching for lepton flavour violation and for the electric dipole moments of the electron and the neutron is also emphasized. (C) 1997 Elsevier Science B.V. C1 IST NAZL FIS NUCL,I-56126 PISA,ITALY. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,BERKELEY,CA 94720. RP Barbieri, R (reprint author), UNIV PISA,DEPT PHYS,I-56126 PISA,ITALY. RI Romanino, Andrea/I-3480-2012 OI Romanino, Andrea/0000-0002-5915-4747 NR 34 TC 120 Z9 120 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 22 PY 1997 VL 401 IS 1-2 BP 47 EP 53 DI 10.1016/S0370-2693(97)00372-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200007 ER PT J AU Frabetti, PL Cheung, HWK Cumalat, JP Dallapiccola, C Ginkel, JF Johns, WE Nehring, MS Butler, JN Cihangir, S Gaines, I Garbincius, PH Garren, L Gourlay, SA Harding, DJ Kasper, P Kreymer, A Lebrun, P Shukla, S Vittone, M Bianco, S Fabbri, FL Sarwar, S Zallo, A Culbertson, R Gardner, RW Greene, R Wiss, J Alimonti, G Bellini, G Boschini, M Brambilla, D Caccianiga, B Cinquini, L DiCorato, M Giammarchi, M Gullotta, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Meroni, E Moroni, L Pedrini, D Perasso, L Prelz, F Sala, A Sala, S Torretta, D Buchholz, D Claes, D Gobbi, B OReilly, B Bishop, JM Cason, NM Kennedy, CJ Kim, GN Lin, TF Puseljic, DL Ruchti, RC Shephard, WD Swiatek, JA Zu, ZY Arena, V Boca, G Castoldi, C Gianini, G Ratti, SP Riccardi, C Viola, L Vitulo, P Lopeze, A Grim, GP Paolone, VS Yager, PM Wilson, JR Sheldon, PD Davenport, F Danyo, K Handler, T Cheon, BG Kang, JS Kim, KY AF Frabetti, PL Cheung, HWK Cumalat, JP Dallapiccola, C Ginkel, JF Johns, WE Nehring, MS Butler, JN Cihangir, S Gaines, I Garbincius, PH Garren, L Gourlay, SA Harding, DJ Kasper, P Kreymer, A Lebrun, P Shukla, S Vittone, M Bianco, S Fabbri, FL Sarwar, S Zallo, A Culbertson, R Gardner, RW Greene, R Wiss, J Alimonti, G Bellini, G Boschini, M Brambilla, D Caccianiga, B Cinquini, L DiCorato, M Giammarchi, M Gullotta, M Inzani, P Leveraro, F Malvezzi, S Menasce, D Meroni, E Moroni, L Pedrini, D Perasso, L Prelz, F Sala, A Sala, S Torretta, D Buchholz, D Claes, D Gobbi, B OReilly, B Bishop, JM Cason, NM Kennedy, CJ Kim, GN Lin, TF Puseljic, DL Ruchti, RC Shephard, WD Swiatek, JA Zu, ZY Arena, V Boca, G Castoldi, C Gianini, G Ratti, SP Riccardi, C Viola, L Vitulo, P Lopeze, A Grim, GP Paolone, VS Yager, PM Wilson, JR Sheldon, PD Davenport, F Danyo, K Handler, T Cheon, BG Kang, JS Kim, KY TI Study of charged hadronic five-body decays of the D+ and D-s(+) mesons SO PHYSICS LETTERS B LA English DT Article ID CHARMED MESONS; NONLEPTONIC DECAYS; DALITZ PLOTS; DS+/ AB Charged hadronic five-body decays of D+ and D-s(+) mesons have been studied in the E687 photoproduction experiment at Fermilab. We report the first compelling evidence of the decay mode D+,D-s(+)-->pi(-)pi(-)pi(+)pi(+)pi(+) and the measurements of the decays D--->K(-)pi(-)pi(+)pi(+)pi(+), D-s(+)-->K(-)K(+)pi(-)pi(+)pi(+) and D-s(+)-->phi pi(-)pi(+)pi(+). An analysis of the D+-->K(-)pi(-)pi(+)pi(+)pi(+) resonance structure is also presented. (C) 1997 Published by Elsevier Science B.V. C1 IST NAZL FIS NUCL,I-40126 BOLOGNA,ITALY. UNIV COLORADO,BOULDER,CO 80309. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. IST NAZL FIS NUCL,NAZL FRASCATI LAB,I-00044 FRASCATI,ITALY. UNIV ILLINOIS,URBANA,IL 61801. IST NAZL FIS NUCL,I-20133 MILAN,ITALY. UNIV MILAN,DIPARTIMENTO FIS,I-20133 MILAN,ITALY. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV PAVIA,DIPARTIMENTO FIS NUCL & TEOR,I-27100 PAVIA,ITALY. IST NAZL FIS NUCL,I-27100 PAVIA,ITALY. UNIV PUERTO RICO,MAYAGUEZ,PR 00708. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV S CAROLINA,COLUMBIA,SC 29208. VANDERBILT UNIV,NASHVILLE,TN 37235. UNIV N CAROLINA,ASHEVILLE,NC 28804. UNIV TENNESSEE,KNOXVILLE,TN 37996. KOREA UNIV,SEOUL 136701,SOUTH KOREA. RP Frabetti, PL (reprint author), UNIV BOLOGNA,DIPARTIMENTO FIS,I-40126 BOLOGNA,ITALY. RI Menasce, Dario Livio/A-2168-2016; Gianini, Gabriele/M-5195-2014; OI Menasce, Dario Livio/0000-0002-9918-1686; Gianini, Gabriele/0000-0001-5186-0199; bianco, stefano/0000-0002-8300-4124 NR 18 TC 2 Z9 2 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 22 PY 1997 VL 401 IS 1-2 BP 131 EP 138 DI 10.1016/S0370-2693(97)00421-8 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200017 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 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 Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, 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 Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X 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 DAllessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y 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 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 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 Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY 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 Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR 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 Muijs, AJM 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 Petersen, B 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 Rattraggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K 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 Sanders, MP Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A 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 Su, 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 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 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 Bourilkov, D Bourquin, M Braccini, S Branson, JG Brigljevic, V Brock, IC Buffini, A Buijs, A Burger, JD Burger, WJ Busenitz, J Button, 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 Chekanov, SV Chemarin, M Chen, A Chen, G Chen, GM Chen, HF Chen, HS Chereau, X 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 DAllessandro, R deAsmundis, R Degre, A Deiters, K dellaVolpe, D Denes, P DeNotaristefani, F DiBitonto, D Diemoz, M vanDierendonck, D DiLodovico, F Dionisi, C Dittmar, M Dominguez, A Doria, A Dova, MT Drago, E Duchesneau, D Duinker, P Duran, I Dutta, S Easo, S Efremenko, Y 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 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 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 Kunin, A deGuevara, PL Laktineh, I Landi, G Lapoint, C LassilaPerini, K Laurikainen, P Lebeau, M Lebedev, A Lebrun, P Lecomte, P Lecoq, P LeCoultre, P Lee, JS Lee, KY 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 Mangeol, D Mangla, S Marchesini, P Marin, A Martin, JP Marzano, F Massaro, GGG McNally, D McNeil, RR 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 Muijs, AJM 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 Petersen, B 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 Rattraggi, M Raven, G Razis, P Read, K Ren, D Rescigno, M Reucroft, S vanRhee, T Riemann, S Riles, K 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 Sanders, MP Santocchia, A Sarakinos, ME Sarkar, S Sassowsky, M Schafer, C Schegelsky, V SchmidtKaerst, S Schmitz, D Schmitz, P Scholz, N Schopper, H Schotanus, DJ Schwenke, J Schwering, G Sciacca, C Sciarrino, D Servoli, L Shevchenko, S Shivarov, N Shoutko, V Shukla, J Shumilov, E Shvorob, A Siedenburg, T Son, D Sopczak, A 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 Su, 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 Zhu, GY Zhu, RY Zichichi, A Ziegler, F TI Search for excited leptons in e(+)e(-) annihilation at root s=161 GeV SO PHYSICS LETTERS B LA English DT Article ID LUND MONTE-CARLO; JET FRAGMENTATION; BHABHA SCATTERING; MAGNETIC-MOMENT; PAIR PRODUCTION; L3 EXPERIMENT; E+E-PHYSICS; Z0 DECAYS; LEP; ELECTRONS AB A search for excited leptons e*, mu*, tau* and nu(e)* in e(+)e(-)collisions at root s = 161 GeV is performed using the 10.8 pb(-1) of data collected by the L3 detector at LEP. No evidence has been found for their existence. From an analysis of the expected l*l* pair production in the channels ee gamma gamma, mu mu gamma, tau tau gamma gamma, eeWW, and nu nu gamma gamma, the lower mass limits at 95% C.L. are 79.7 GeV for e*, 79.9 GeV for mu*, 79.3 GeV for tau* and 71.2 GeV for nu(e)* assuming the same couplings as for standard leptons. From an analysis of the expected ll* single production in channels ee gamma, mu mu gamma, tau tau gamma, nu(e)eW and nu nu gamma, the upper limits on the couplings lambda/m(l*) up to m(l*) = 161 GeV are determined. (C) 1997 Published by Elsevier Science B.V. 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. UNIV BOLOGNA, I-40126 BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. TATA INST FUNDAMENTAL RES, BOMBAY 400005, MAHARASHTRA, INDIA. BOSTON UNIV, BOSTON, MA 02215 USA. NORTHEASTERN UNIV, BOSTON, MA 02115 USA. INST ATOM PHYS, R-76900 BUCHAREST, ROMANIA. UNIV BUCHAREST, R-76900 BUCHAREST, ROMANIA. HUNGARIAN ACAD SCI, CENT RES INST PHYS, H-1525 BUDAPEST 114, HUNGARY. HARVARD UNIV, CAMBRIDGE, MA 02139 USA. MIT, CAMBRIDGE, MA 02139 USA. IST NAZL OTTICA, 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, USTC, HEFEI 230029, ANHUI, PEOPLES R CHINA. SEFT, RES INST HIGH ENERGY PHYS, SF-00014 HELSINKI, FINLAND. UNIV LAUSANNE, CH-1015 LAUSANNE, SWITZERLAND. IST NAZL FIS NUCL, I-73100 LECCE, ITALY. UNIV LECCE, I-73100 LECCE, ITALY. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87544 USA. UNIV LYON 1, CNRS, IN2P3, INST PHYS NUCL LYON, F-69622 VILLEURBANNE, FRANCE. CIEMAT, E-28040 MADRID, SPAIN. 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. 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. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, 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 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. HIGH ENERGY PHYS GRP, TAIPEI, TAIWAN. LOUISIANA STATE UNIV, BATON ROUGE, LA 70803 USA. RP Acciarri, M (reprint author), 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; 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; 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 43 TC 19 Z9 19 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 MAY 22 PY 1997 VL 401 IS 1-2 BP 139 EP 149 DI 10.1016/S0370-2693(97)00404-8 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200018 ER PT J AU Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G 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 DePasquale, S Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Anreodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB 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 Kotanski, A Abbiendi, G Abramowicz, H Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burrow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE 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, SM Wu, JT Cloth, P Filges, D An, SH Lee, SB Nam, SW Park, HS Park, SK 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 Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Kobrin, VD Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotov, NP Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, VM Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Feild, RG Oh, BY Okrasinski, JR 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 Schwarzer, O Walenta, AH Briskin, G Dagan, S Doeker, T Levy, A Abe, T Fleck, JI Inuzuka, M Ishii, T Kuze, M Nagano, K Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC 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 Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D ZerZion, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB AF Breitweg, J Derrick, M Krakauer, D Magill, S Mikunas, D Musgrave, B Repond, J Stanek, R Talaga, RL Yoshida, R Zhang, H Mattingly, MCK Anselmo, F Antonioli, P Bari, G Basile, M Bellagamba, L Boscherini, D Bruni, A Bruni, G 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 DePasquale, S Pesci, A Polini, A Sartorelli, G Garcia, YZ Zichichi, A Amelung, C Bornheim, A Brock, I Coboken, K Crittenden, J Deffner, R Eckert, M Feld, L Grothe, M Hartmann, H Heinloth, K Heinz, L Hilger, E Jakob, HP Katz, UF Paul, E Pfeiffer, M Rembser, C Stamm, J Wedemeyer, R Bailey, DS CampbellRobson, S Cottingham, WN Foster, B HallWilton, R Hayes, ME Heath, GP Heath, HF Piccioni, D Roff, DG Tapper, RJ Anreodo, M Ayad, R Capua, M Garfagnini, A Iannotti, L Schioppa, M Susinno, G Kim, JY Lee, JH Lim, IT Pac, MY Caldwell, A Cartiglia, N Jing, Z Liu, W Parsons, JA Ritz, S Sampson, S Sciulli, F Straub, PB 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 Kotanski, A Abbiendi, G Abramowicz, H Bauerdick, LAT Behrens, U Beier, H Bienlein, JK Cases, G Deppe, O Desler, K Drews, G Gilkinson, DJ Glasman, C Gottlicher, P GrosseKnetter, J Haas, T Hain, W Hasell, D Hessling, H Iga, Y Johnson, KF Kasemann, M Koch, W Kotz, U Kowalski, H Labs, J Lindemann, L Lohr, B Lowe, M Mainusch, J Manczak, O Milewski, J Monteiro, T Ng, JST Notz, D Ohrenberg, K Park, IH Pellegrino, A Pelucchi, F Piotrzkowski, K Roco, M Rohde, M Roldan, J Savin, AA Schneekloth, U Schulz, W Selonke, F Surrow, B Tassi, E Voss, T Westphal, D Wolf, G Wollmer, U Youngman, C Zarnecki, AF Zeuner, W Burrow, BD Grabosch, HJ Meyer, A Schlenstedt, S Barbagli, G Gallo, E Pelfer, P Maccarrone, G Votano, L Bamberger, A Eisenhardt, S Markun, P Trefzger, T Wolfle, S Bromley, JT Brook, NH Bussey, PJ Doyle, AT Saxon, DH Sinclair, LE Strickland, E Utley, ML Waugh, R Wilson, AS Bohnet, I Gendner, N Holm, U MeyerLarsen, A Salehi, H Wick, K Gladilin, LK Klanner, R Lohrmann, E Poelz, G Schott, W Zetsche, F Bacon, TC Butterworth, I Cole, JE 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, SM Wu, JT Cloth, P Filges, D An, SH Lee, SB Nam, SW Park, HS Park, SK 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 Murray, WN Ochs, A Riveline, M Stairs, DG StLaurent, M Ullmann, R Tsurugai, T Bashkirov, V Dolgoshein, BA Stifutkin, A Bashindzhagyan, GL Ermolov, PF Golubkov, YA Kobrin, VD Korzhavina, IA Kuzmin, VA Lukina, OY Proskuryakov, AS Shcheglova, LM Solomin, AN Zotov, NP Bokel, C Botje, M Brummer, N Chlebana, F Engelen, J deKamps, M Kooijman, P Kruse, A vanSighem, A Tiecke, H Verkerke, W Vossebeld, J Vreeswijk, VM Wiggers, L deWolf, E Acosta, D Bylsma, B Durkin, LS Gilmore, J Ginsburg, CM Kim, CL Ling, TY Nylander, P Romanowski, TA Blaikley, HE Cashmore, RJ CooperSarkar, AM Devenish, RCE Edmonds, JK Harnew, N Lancaster, M McFall, JD Nath, C Noyes, VA Quadt, A Tickner, JR Uijterwaal, H Walczak, R Waters, DS Yip, T Bertolin, A Brugnera, R Carlin, R DalCorso, F Dosselli, U Limentani, S Morandin, M Posocco, M Stanco, L Stroili, R Voci, C Bulmahn, J Feild, RG Oh, BY Okrasinski, JR 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 Schwarzer, O Walenta, AH Briskin, G Dagan, S Doeker, T Levy, A Abe, T Fleck, JI Inuzuka, M Ishii, T Kuze, M Nagano, K Nakao, M Suzuki, I Tokushuku, K Umemori, K Yamada, S Yamazaki, Y Hamatsu, R Hirose, T Homma, K Kitamura, S Matsushita, T Yamauchi, K Cirio, R Costa, M Ferrero, MI Maselli, S Monaco, V Peroni, C Petrucci, MC Sacchi, R Solano, A Staiano, A Dardo, M Bailey, DC 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 Ciborowski, J Grzelak, G Kasprzak, M Muchorowski, K Nowak, RJ Pawlak, JM Pawlak, R Tymieniecka, T Wroblewski, AK Zakrzewski, JA Adamus, M Coldewey, C Eisenberg, Y Hochman, D Karshon, U Revel, D ZerZion, D Badgett, WF Chapin, D Cross, R Dasu, S Foudas, C Loveless, RJ Mattingly, S Reeder, DD Smith, WH Vaiciulis, A Wodarczyk, M Bhadra, S Frisken, WR Khakzad, M Schmidke, WB TI Differential cross sections of D*(+/-) photoproduction in ep collisions at HERA SO PHYSICS LETTERS B LA English DT Article ID CENTRAL TRACKING DETECTOR; HEAVY-QUARK CORRELATIONS; ZEUS BARREL CALORIMETER; HADRON-COLLISIONS; FLAVOR PRODUCTION; E+E ANNIHILATION; QCD CORRECTIONS; FRAGMENTATION; PHOTON; DISTRIBUTIONS AB Inclusive photoproduction of D*(+)/- in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality Q(2) < 4 GeV2. The cross section sigma(ep) --> D*X integrated over the kinematic region p(D)*(perpendicular to) 3 GeV acid -1.5 < eta(D)* < 1.0 is (10.6 +/- 1.7(stat.)+/-(1.6)(1.3)(syst.)) nb. Differential cross sections as functions of p(D)*(perpendicular to), eta(D)* and W are given. The data are compared with two next-to-leading order perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data. (C) 1997 Published by Elsevier Science B.V. C1 ANDREWS UNIV, BERRIEN SPRINGS, MI 49104 USA. UNIV BOLOGNA, BOLOGNA, ITALY. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. UNIV BONN, INST PHYS, D-5300 BONN, GERMANY. UNIV BRISTOL, HH WILLS PHYS LAB, BRISTOL BS8 1TL, AVON, ENGLAND. UNIV CALABRIA, DEPT PHYS, I-87036 COSENZA, ITALY. IST NAZL FIS NUCL, COSENZA, ITALY. CHONNAM NATL UNIV, KWANGJU 500757, SOUTH KOREA. COLUMBIA UNIV, NEVIS LABS, IRVINGTON, NY USA. INST NUCL PHYS, KRAKOW, POLAND. ACAD MIN & MET, FAC PHYS & NUCL TECH, KRAKOW, POLAND. JAGIELLONIAN UNIV, DEPT PHYS, KRAKOW, POLAND. DESY, D-2000 HAMBURG, GERMANY. DESY, IFH ZEUTHEN, 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-7800 FREIBURG, GERMANY. UNIV GLASGOW, DEPT PHYS & ASTRON, GLASGOW, LANARK, SCOTLAND. UNIV HAMBURG, INST EXPT PHYS 2, D-2000 HAMBURG, GERMANY. UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, HIGH ENERGY NUCL PHYS GRP, LONDON, ENGLAND. UNIV IOWA, DEPT PHYS & ASTRON, IOWA CITY, IA 52242 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST KERNPHYS, D-5170 JULICH, GERMANY. KOREA UNIV, SEOUL 136701, SOUTH KOREA. UNIV AUTONOMA MADRID, DEPT FIS TEOR, MADRID, SPAIN. MCGILL UNIV, DEPT PHYS, MONTREAL, PQ, CANADA. MEIJI GAKUIN UNIV, FAC GEN EDUC, YOKOHAMA, KANAGAWA, JAPAN. MOSCOW PHYS ENGN INST, MOSCOW, RUSSIA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW, RUSSIA. NIKHEF H, NL-1009 DB AMSTERDAM, NETHERLANDS. UNIV AMSTERDAM, NL-1012 WX AMSTERDAM, NETHERLANDS. OHIO STATE UNIV, DEPT PHYS, COLUMBUS, OH 43210 USA. UNIV OXFORD, DEPT PHYS, OXFORD, ENGLAND. UNIV PADUA, DIPARTIMENTO FIS, PADUA, ITALY. IST NAZL FIS NUCL, PADUA, ITALY. PENN STATE UNIV, DEPT PHYS, UNIVERSITY PK, PA 16802 USA. UNIV ROMA LA SAPIENZA, DIPARTIMENTO FIS, I-00185 ROME, ITALY. IST NAZL FIS NUCL, ROME, ITALY. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV GESAMTHSCH SIEGEN, FACHBEREICH PHYS, D-57068 SIEGEN, GERMANY. TEL AVIV UNIV, RAYMOND & BEVERLY SACKLER FAC EXACT SCI, SCH PHYS, IL-69978 TEL AVIV, ISRAEL. UNIV TOKYO, INST NUCL STUDY, TOKYO, JAPAN. TOKYO METROPOLITAN UNIV, DEPT PHYS, TOKYO, JAPAN. UNIV TURIN, DIPARTIMENTO FIS SPERIMENTALE, TURIN, ITALY. IST NAZL FIS NUCL, I-10125 TURIN, ITALY. INFN, ALESSANDRIA, ITALY. UNIV TURIN, FAC SCI 2, I-10124 TURIN, ITALY. UNIV TORONTO, DEPT PHYS, TORONTO, ON, CANADA. UCL, DEPT PHYS & ASTRON, LONDON, ENGLAND. VIRGINIA POLYTECH INST & STATE UNIV, BLACKSBURG, VA 24061 USA. UNIV WARSAW, INST EXPT PHYS, 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, N YORK, ON M3J 1P3, CANADA. CNR, IROE, I-50127 FLORENCE, ITALY. RP Breitweg, J (reprint author), ARGONNE NATL LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI 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; Tassi, Enrico/K-3958-2015; Gladilin, Leonid/B-5226-2011; Morandin, Mauro/A-3308-2016; Bashkirov, Vladimir/A-4818-2008; De Pasquale, Salvatore/B-9165-2008; Lancaster, Mark/C-1693-2008; Solomin, Anatoly/C-3072-2016; Capua, Marcella/A-8549-2015; OI 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; Gladilin, Leonid/0000-0001-9422-8636; Morandin, Mauro/0000-0003-4708-4240; De Pasquale, Salvatore/0000-0001-9236-0748; Castellini, Guido/0000-0002-0177-0643; Capua, Marcella/0000-0002-2443-6525; Lancaster, Mark/0000-0002-8872-7292; Graciani Diaz, Ricardo/0000-0001-7166-5198 NR 48 TC 21 Z9 21 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 22 PY 1997 VL 401 IS 1-2 BP 192 EP 206 DI 10.1016/S0370-2693(97)00422-X PG 15 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XB402 UT WOS:A1997XB40200023 ER PT J AU Henderson, DO Ueda, A Tung, YS Mu, R White, WC Zuhr, RA Zhu, JG AF Henderson, DO Ueda, A Tung, YS Mu, R White, WC Zuhr, RA Zhu, JG TI Surface-phonon characterization of InP, GaP and GaAs quantum dots confined in dielectric hosts SO JOURNAL OF PHYSICS D-APPLIED PHYSICS LA English DT Article; Proceedings Paper CT Material-Research-Society Symposium on the Spectroscopy of Heterojunctions CY 1995 CL BOSTON, MA SP Mat Res Soc ID OPTICAL-PROPERTIES; LAYERED SEMICONDUCTORS; RAMAN-SCATTERING; PARTICLES; CRYSTALS AB The proper combination of sequential ion implantation and thermal annealing can successfully fabricate binary semiconductor quantum dots (QDs), such as InP, GaP and GaAs QDs. Far-infrared reflectance techniques can be effectively employed to identify the species formed before and after various thermal treatments via probing molecular vibrations and surface phonons of the QDs. This technique is very useful for the characterization of an ultra-thin layer of foreign species on or in the near surface of the bulk substrate materials. In addition, this technique is non-destructive, simple and versatile. The examples given in the present report are InP and GaP QDs formed in fused silica and GaAs QDs formed in fused silica and in Al2O3 [0001] substrates. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Henderson, DO (reprint author), FISK UNIV,DEPT PHYS,PHYS CHEM LAB,NASHVILLE,TN 37208, USA. NR 21 TC 5 Z9 6 U1 1 U2 5 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 MAY 21 PY 1997 VL 30 IS 10 BP 1432 EP 1435 DI 10.1088/0022-3727/30/10/007 PG 4 WC Physics, Applied SC Physics GA XA354 UT WOS:A1997XA35400007 ER PT J AU Fenwick, CW English, AM Wishart, JF AF Fenwick, CW English, AM Wishart, JF TI pH and driving force dependence of intramolecular oxyferryl heme reduction in myoglobin SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CYTOCHROME-C PEROXIDASE; RANGE ELECTRON-TRANSFER; SPERM WHALE MYOGLOBIN; HORSERADISH-PEROXIDASE; AMMINE COMPLEXES; HIGH-RESOLUTION; ALKALINE FORMS; LIGAND-BINDING; COMPOUND-I; CHEMISTRY AB The kinetics of oxyferryl (Fe-IV=O) heme reduction in horst heart myoglobin (Mb) by a(4)LRu(II) (a = NH3; L = NH3, pyridine, isonicotinamide) bound at the surface His48 were investigated with pulse radiolysis. The observed first-order rate constants (k(obs1)) decreased with increasing pH and reduction potential for the a(4)LRu centers (E degrees/ Ru-III/II = 77, 330, and 400 mV for L = NH3, Pyr, and Isn). Rate-pD data obtained in D2O for the a(4)LRu derivative revealed the presence of an equilibrium isotope effect, and a pK(a) of 5.7 (6.2 in D2O) was obtained for the acid-base group, which is assigned to the distal His64. A mechanism where protonation precedes ET provides a good fit of the kinetic data for the three a(4)LRu derivatives. Marcus theory analysis of the k(ET) (0.74, 1.8, and 3.6 s(-1) for L = Isn. Pyr, and NH3) extracted from the k(obs1) values yielded a reorganization energy (lambda) of 1.8 for Ru-II --> Fe-IV=O ET in the a(4)LRu derivatives but a lambda of 2.1 eV for the a(5)Ru derivative, From the latter, it is concluded that ET is strongly gated in the a(5)Ru derivative, and this is assumed to be the major reason for the low reactivity of Fe-IV=O in Mb at high -Delta G degrees. C1 BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. CONCORDIA UNIV,DEPT CHEM & BIOCHEM,MONTREAL,PQ H3G 1M8,CANADA. RI Wishart, James/L-6303-2013 OI Wishart, James/0000-0002-0488-7636 NR 78 TC 32 Z9 33 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 MAY 21 PY 1997 VL 119 IS 20 BP 4758 EP 4764 DI 10.1021/ja963108g PG 7 WC Chemistry, Multidisciplinary SC Chemistry GA XA480 UT WOS:A1997XA48000023 ER PT J AU Pierre, DM Goldman, D BarYam, Y Perelson, AS AF Pierre, DM Goldman, D BarYam, Y Perelson, AS TI Somatic evolution in the immune system: The need for germinal centers for efficient affinity maturation SO JOURNAL OF THEORETICAL BIOLOGY LA English DT Article ID CENTER B-CELLS; CLONAL SELECTION; ANTIBODY PRODUCTION; MATHEMATICAL MODEL; RANDOM MUTAGENESIS; ANTIGEN; MUTATION; MEMORY; (4-HYDROXY-3-NITROPHENYL)ACETYL; SPECIFICITY AB In the course of a humoral immune response, the average affinity of antibody for the immunizing antigen can increase in time. This process of affinity maturation is due to antigen-driven selection of higher affinity B cell clones and somatic hypermutation of the genes that code for the antibody variable region. Through the use of simulation models we show that the efficiency of affinity maturation is substantially improved if mutation and selection occur in germinal centers, specialized regions of lymphoid tissues, rather than in the body as a whole. We show that confining mutation and selection to germinal centers decouples the problem of affinity maturation from the problem of antigen elimination. In the germinal centers, stored antigen, high rates of B cell proliferation and apoptosis combine to create an environment where effective maturation occurs even after the primary response has eliminated much or all of the free antigen. Kepler and Perelson suggested that if hypermutation were turned on and off in a phasic manner, affinity maturation could be made more efficient under circumstances when affinity-improving mutations have a low probability of occurrence. We confirm this in the context of a stochastic model. However, even in the absence of phasic mutation, we show that affinity maturation is significantly improved when proliferation, mutation, and selection are restricted to germinal centers as opposed to occurring systemically. (C) 1997 Academic Press Limited. C1 MIT, DEPT PHYS, CAMBRIDGE, MA 02139 USA. BOSTON UNIV, DEPT AEROSP & MECH ENGN, BOSTON, MA 02215 USA. BOSTON UNIV, DEPT ELECT COMP & SYST ENGN, BOSTON, MA 02215 USA. LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. OI Goldman, Daniel/0000-0002-8707-5536 FU NIAID NIH HHS [AI28433] NR 53 TC 7 Z9 7 U1 0 U2 0 PU ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD PI LONDON PA 24-28 OVAL RD, LONDON NW1 7DX, ENGLAND SN 0022-5193 J9 J THEOR BIOL JI J. Theor. Biol. PD MAY 21 PY 1997 VL 186 IS 2 BP 159 EP 171 DI 10.1006/jtbi.1996.0350 PG 13 WC Biology; Mathematical & Computational Biology SC Life Sciences & Biomedicine - Other Topics; Mathematical & Computational Biology GA XA380 UT WOS:A1997XA38000003 PM 9196657 ER PT J AU Alcock, C Allsman, RA Alves, DR Axelrod, TS Bennett, DP Charles, PA Cook, KH ODonoghue, D Freeman, KC Griest, K Guern, J Lehner, MJ Livio, M Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Southwell, KA Stubbs, CW Sutherland, W Welch, DL AF Alcock, C Allsman, RA Alves, DR Axelrod, TS Bennett, DP Charles, PA Cook, KH ODonoghue, D Freeman, KC Griest, K Guern, J Lehner, MJ Livio, M Marshall, SL Minniti, D Peterson, BA Pratt, MR Quinn, PJ Rodgers, AW Southwell, KA Stubbs, CW Sutherland, W Welch, DL TI Optical photometry of the eclipsing Large Magellanic Cloud supersoft source CAL87 SO MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY LA English DT Article DE accretion, accretion discs; binaries, close; binaries, spectroscopic; stars, individual, CAL87; Magellanic Clouds; X-rays, stars ID X-RAY SOURCES; SPACED DATA; BINARY; CAL-87; LMC; MODELS AB We present optical photometry of the eclipsing supersoft source CAL 87. These observations comprise long-term data accumulated as a by-product of the MACHO Project, and high-speed, white-light photometry of a single eclipse. We (i) derive an improved ephemeris of T-0 = HJD 245 0111.5144(3) + 0.442 677 14(6)E for the time of minimum light, (ii) find the eclipse structure to be stable over a period of similar to 4 yr, and (iii) investigate the colour variation as a function of orbital phase. The resolution afforded by the high-speed nature of the white-light observations enables us to see new structure in the light-curve morphology. C1 UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. AUSTRALIAN NATL UNIV,SUPERCOMP FACIL,CANBERRA,ACT 0200,AUSTRALIA. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. AUSTRALIAN NATL UNIV,MT STROMLO & SIDING SPRING OBSERV,WESTON,ACT 2611,AUSTRALIA. UNIV OXFORD,DEPT ASTROPHYS,NUCL & ASTROPHYS LAB,OXFORD OX1 3RH,ENGLAND. UNIV CAPE TOWN,DEPT ASTRON,ZA-7700 RONDEBOSCH,SOUTH AFRICA. UNIV CALIF SAN DIEGO,DEPT PHYS,SAN DIEGO,CA 92093. SPACE TELESCOPE SCI INST,BALTIMORE,MD 21218. UNIV CALIF SANTA BARBARA,DEPT PHYS,SANTA BARBARA,CA 93106. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. UNIV WASHINGTON,DEPT PHYS,SEATTLE,WA 98195. MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. RP Alcock, C (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Stubbs, Christopher/C-2829-2012; Quinn, Peter/B-3638-2013; OI Stubbs, Christopher/0000-0003-0347-1724; Lehner, Matthew/0000-0003-4077-0985 NR 31 TC 11 Z9 11 U1 0 U2 1 PU BLACKWELL SCIENCE LTD PI OXFORD PA P O BOX 88, OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0NE SN 0035-8711 J9 MON NOT R ASTRON SOC JI Mon. Not. Roy. Astron. Soc. PD MAY 21 PY 1997 VL 287 IS 3 BP 699 EP 704 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XB175 UT WOS:A1997XB17500026 ER PT J AU MacLachlan, JA AF MacLachlan, JA TI Fermilab R&D program in medium energy electron cooling SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 11th International Advanced ICFA Beam Dynamic Workshop on Beam Cooling and Instability Damping CY JUN 18-26, 1996 CL MOSCOW, RUSSIA SP ICFA DE electron cooling; antiproton ID INTERMEDIATE AB Fermilab began an R&D program in medium energy electron cooling in April 1995 with the object of cooling 8 GeV antiprotons in a new 3.3 km permanent magnet storage ring (Recycler) to be built in the same tunnel as the Main Injector (MI). The MI is to be completed in 1998, and it is planned to install the Recycler by the end of 1997 to reduce interference during the final rush of MI installation. Although the Recycler will employ stochastic cooling initially, its potential for contributing an order of magnitude to Tevatron collider luminosity is tied to electron cooling. The short time scale and Fermilab's limited familiarity with low energy electron beams has given rise to a two-phase development plan. The first phase is to build a cooling system based on an electron beam of greater than or equal to 200 mA before the year 2000. The second phase of about three years is planned to reach an electron current of 2 A or more. This report describes the general scheme for high luminosity collider operation as well as the R&D plan and progress to date. RP MacLachlan, JA (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,MS 323,BATAVIA,IL 60510, USA. NR 18 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 1997 VL 391 IS 1 BP 131 EP 137 DI 10.1016/S0168-9002(96)01195-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XK492 UT WOS:A1997XK49200026 ER PT J AU Nagaitsev, S AF Nagaitsev, S TI Electron cooling for the Fermilab recycler SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 11th International Advanced ICFA Beam Dynamic Workshop on Beam Cooling and Instability Damping CY JUN 18-26, 1996 CL MOSCOW, RUSSIA SP ICFA DE storage ring; beam cooling AB In all scenarios of the possible Tevatron upgrades, luminosity is essentially proportional to the number of antiprotons. Thus, a tenfold increase in luminosity could be achieved by putting five times more protons on the antiproton production target and gaining an additional factor of two from recycling antiprotons left over from the previous store. Stacking and storing ten times more antiprotons puts an unbearable burden on the stochastic cooling system of the existing accumulator ring. Thus, one is led to consider an additional stage of antiproton storage, the so called recycler ring. Electron cooling of the 8 GeV antiprotons in the recycler could provide an attractive way around the problems of large stacks. Such a system would look much like the IUCF proposal to cool 12 GeV protons in the SSC medium energy booster [1]. Although electron cooling has now become a routine tool in many laboratories, its use has been restricted to lower energy accelerators (<500 MeV/nucleon). An R&D program is currently under way at Fermilab to extend electron cooling technology to the GeV range. This paper describes the electron cooling system design as well as the recycler ring parameters required to accommodate this system. RP Nagaitsev, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 5 TC 7 Z9 7 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 1997 VL 391 IS 1 BP 142 EP 146 DI 10.1016/S0168-9002(96)01196-5 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XK492 UT WOS:A1997XK49200028 ER PT J AU Church, M AF Church, M TI Stochastic cooling at Fermilab SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 11th International Advanced ICFA Beam Dynamic Workshop on Beam Cooling and Instability Damping CY JUN 18-26, 1996 CL MOSCOW, RUSSIA SP ICFA DE stochastic cooling; storage ring; pickups; kickers AB Fermilab now has over 10 years of operational experience with stochastic cooling systems. New techniques and refinements of old techniques continue to push the state of the art. I will discuss recent developments which include strategies for new pickup and kicker arrays, laser signal processing, recent measurements on system performance, bunched beam cooling, new calculational/modeling techniques, and requirements for future accelerator upgrades. RP Church, M (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 1997 VL 391 IS 1 BP 172 EP 175 DI 10.1016/S0168-9002(97)00358-6 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XK492 UT WOS:A1997XK49200033 ER PT J AU Lebedev, VA Hangst, JS Madsen, N Labrador, A AF Lebedev, VA Hangst, JS Madsen, N Labrador, A TI Single and multiple intrabeam scattering in a laser cooled beam SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 11th International Advanced ICFA Beam Dynamic Workshop on Beam Cooling and Instability Damping CY JUN 18-26, 1996 CL MOSCOW, RUSSIA SP ICFA DE laser cooling; beam cooling; intrabeam scattering ID ION-BEAM AB The dependence of the laser cooling force on velocity is strongly non-linear and consists of two narrow peaks associated with co- and counter-propagating laser beams. Under these conditions a single intrabeam scattering event can knock a particle out of the cooling range. This creates large non-Gaussian tails in the distribution function for longitudinal velocity. A theoretical model describing single and multiple intrabeam scattering is considered. A detailed analysis of the scattering and its comparison with experimental data for the ASTRID storage ring are performed. C1 AARHUS UNIV,INST PHYS & ASTRON,DK-8000 AARHUS C,DENMARK. RP Lebedev, VA (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,12000 JEFFERSON AVE,NEWPORT NEWS,VA 23606, USA. RI Madsen, Niels/G-3548-2013 OI Madsen, Niels/0000-0002-7372-0784 NR 7 TC 6 Z9 6 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 21 PY 1997 VL 391 IS 1 BP 176 EP 187 DI 10.1016/S0168-9002(97)00227-1 PG 12 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XK492 UT WOS:A1997XK49200034 ER PT J AU Hancock, RD Schauer, FR Lucht, RP Farrow, RL AF Hancock, RD Schauer, FR Lucht, RP Farrow, RL TI Dual-pump coherent anti-Stokes Raman scattering measurements of nitrogen and oxygen in a laminar jet diffusion flame SO APPLIED OPTICS LA English DT Article DE CARS; dual-pump CARS; three-laser CARS; diffusion flames ID ROTATIONAL CARS; SPECTROSCOPY; TEMPERATURE; COMBUSTION; CO AB Dual-pump coherent anti-Stokes Raman scattering (CARS) has been demonstrated for the simultaneous measurement of gas-phase temperature and concentrations of molecular nitrogen and oxygen. A polarization technique was used to vary the relative intensities of the two CARS signals and expand the dynamic range of the relative concentration measurements. Detailed temperature and oxygen mole fraction measurements were performed in the stabilization region of a hydrogen-nitrogen jet diffusion flame. These results indicate that there is a region below the nozzle exit where significant amounts of oxygen are found on the fuel side of the peak flame temperature profile. (C) 1997 Optical Society of America. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94550. AERO PROP & POWER DIRECTORATE,WRIGHT PATTERSON AFB,OH 45433. RP Hancock, RD (reprint author), UNIV ILLINOIS,DEPT MECH & IND ENGN,1206 W GREEN ST,URBANA,IL 61801, USA. NR 35 TC 37 Z9 38 U1 0 U2 7 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAY 20 PY 1997 VL 36 IS 15 BP 3217 EP 3226 DI 10.1364/AO.36.003217 PG 10 WC Optics SC Optics GA WZ080 UT WOS:A1997WZ08000006 PM 18253329 ER PT J AU Sinclair, MB Butler, MA Ricco, AJ Senturia, SD AF Sinclair, MB Butler, MA Ricco, AJ Senturia, SD TI Synthetic spectra: A tool for correlation spectroscopy SO APPLIED OPTICS LA English DT Article DE synthetic spectra; correlation spectroscopy; diffractive optics; infrared spectroscopy ID GAS SENSORS; PHASE; ALGORITHM AB We show that computer-generated diffractive optical elements can be used to synthesize the infrared spectra of important compounds, and we describe a modified phase-retrieval algorithm useful for the design of elements of this type. In particular, we present the results of calculations of diffractive elements that are capable of synthesizing portions of the infrared spectra of gaseous hydrogen fluoride (KP) and trichloroethylene (TCE). Further, we propose a new type of correlation spectrometer that uses these diffractive elements rather than reference cells for the production of reference spectra. Storage of a large number of diffractive elements, each producing a synthetic spectrum corresponding to a different target compound, in compact-disk-like format will allow a spectrometer of this type to rapidly determine the composition of unknown samples. Other advantages of the proposed correlation spectrometer are also discussed. (C) 1997 Optical Society of America. C1 MIT,DEPT ELECT ENGN,CAMBRIDGE,MA 02139. RP Sinclair, MB (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. RI Ricco, Antonio/A-5273-2010 NR 14 TC 47 Z9 47 U1 0 U2 2 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAY 20 PY 1997 VL 36 IS 15 BP 3342 EP 3348 DI 10.1364/AO.36.003342 PG 7 WC Optics SC Optics GA WZ080 UT WOS:A1997WZ08000024 PM 18253347 ER PT J AU Ratowsky, RP Yang, L Deri, RJ Chang, KW Kallman, JS Trott, G AF Ratowsky, RP Yang, L Deri, RJ Chang, KW Kallman, JS Trott, G TI Laser diode to single-mode fiber ball lens coupling efficiency: Full-wave calculation and measurements SO APPLIED OPTICS LA English DT Article ID MAXWELLS EQUATIONS; GAUSSIAN-BEAM; SCATTERING; SPHERE AB We show that the coupling efficiency from a laser diode (LD) to an optical fiber through a ball lens can be calculated accurately using the exact solution to Maxwell's equations for the scattering of a beam hom a dielectric sphere. Our calculated results agree closely with coupling measurements from an asymmetric LD for two different ball lenses. (C) 1997 Optical Society of America. C1 HEWLETT PACKARD LABS,PALO ALTO,CA 94303. RP Ratowsky, RP (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551, USA. NR 14 TC 14 Z9 15 U1 2 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAY 20 PY 1997 VL 36 IS 15 BP 3435 EP 3438 DI 10.1364/AO.36.003435 PG 4 WC Optics SC Optics GA WZ080 UT WOS:A1997WZ08000037 PM 18253360 ER PT J AU Szapudi, I Szalay, AS AF Szapudi, I Szalay, AS TI Cumulant correlators from the APM SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, statistics; large-scale structure of universe methods, data analysis; methods, statistical ID GALAXY CORRELATION-FUNCTIONS; HIERARCHY; STATISTICS; SKEWNESS AB This work presents a set of new statistics, the cumulant correlators (CCs), aimed at high-precision analysis of the galaxy distribution. They form a symmetric matrix, Q(NM), related to moment correlators in the same way cumulants are related to the moments of the distribution. They encode more information than the usual cumulants S-N, and their extraction from data is similar to the calculation of the two-point correlation function. Perturbation theory (PT), its generalization in the extended perturbation theory (EPT), and the hierarchical assumption (HA) have simple predictions for these statistics. As an example, the factorial moment correlators measured by Szapudi and coworkers in the APM catalog are reanalyzed using this technique. While the previous analysis assumed hierarchical structure constants, this method can directly investigate the validity of the HA, along with PT and EPT. The results in agreement with previous findings indicate that, at the small scales used for this analysis, the APM data support the HA. When all nonlinear corrections are taken into account, it is a good approximation at the 20% level. It appears that PT, and a natural generalization of EPT for CCs, does not provide such a good fit for the APM at small scales. Once the validity of the HA is approximately established, CCs can separate the amplitudes of different tree types in the hierarchy up to fifth order. As an example, the weights for the fourth-order tree topologies are calculated including all nonlinear corrections. C1 JOHNS HOPKINS UNIV,BALTIMORE,MD 21218. RP Szapudi, I (reprint author), NASA,FERMILAB ASTROPHYS CTR,FERMI NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. NR 25 TC 34 Z9 34 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 MAY 20 PY 1997 VL 481 IS 1 BP L1 EP L4 DI 10.1086/310641 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XA546 UT WOS:A1997XA54600001 ER PT J AU Krueger, JK Olah, GA Rokop, SE Zhi, G Stull, JT Trewhella, J AF Krueger, JK Olah, GA Rokop, SE Zhi, G Stull, JT Trewhella, J TI Structures of calmodulin and a functional myosin light chain kinase in the activated complex: A neutron scattering study SO BIOCHEMISTRY LA English DT Article ID X-RAY-SCATTERING; DEPENDENT PROTEIN-KINASE; SMALL-ANGLE SCATTERING; SMOOTH-MUSCLE; INTRASTERIC REGULATION; CATALYTIC SUBUNIT; CRYSTAL-STRUCTURE; PEPTIDE COMPLEX; BINDING DOMAIN; TROPONIN-C AB Calmodulin (CaM) is the major intracellular receptor for Ca2+ and is responsible for the Ca2+-dependent regulation of a wide variety of cellular processes via interactions with a diverse array of target enzymes, Our current view of the structural basis for CaM enzyme activation is based on biophysical studies of CaM complexed with small peptides that model CaM-binding domains. A major concern with interpreting data from these structures in terms of target enzyme activation mechanisms is that the larger enzyme structure might be expected to impose constraints on CaM binding. Full understanding of the molecular mechanism for CaM-dependent enzyme activation requires additional structural information on the interaction of CaM with functional enzymes, We have utilized small-angle X-ray scattering and neutron scattering with contrast variation to obtain the first structural view of CaM complexed with a functional enzyme, an enzymatically active truncation mutant of skeletal muscle myosin light chain kinase (MLCK), Our data show that CaM undergoes an unhindered conformational collapse upon binding MLCK and activates the enzyme by inducing a significant movement autoinhibitory sequences away from the surface of the catalytic core. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. UNIV TEXAS,SW MED CTR,DEPT PHYSIOL,DALLAS,TX 75235. RI Krueger, Joanna/A-3110-2011; OI Trewhella, Jill/0000-0002-8555-6766 FU NHLBI NIH HHS [HL08874, HL06296]; NIGMS NIH HHS [GM40528] NR 41 TC 60 Z9 61 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD MAY 20 PY 1997 VL 36 IS 20 BP 6017 EP 6023 DI 10.1021/bi9702703 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA XA274 UT WOS:A1997XA27400012 PM 9166772 ER PT J AU Overbeek, R Larsen, N Smith, W Maltsev, N Selkov, E AF Overbeek, R Larsen, N Smith, W Maltsev, N Selkov, E TI Representation of function: The next step (Reprinted from Gene-Combis, vol 191, pg GC1-GC9, 1997) SO GENE LA English DT Reprint C1 MICHIGAN STATE UNIV,CTR MICROBIAL ECOL,E LANSING,MI 48824. RUSSIAN ACAD SCI,INST THEORET BIOPHYS,PUSHCHINO,MOSCOW REGION,RUSSIA. RP Overbeek, R (reprint author), ARGONNE NATL LAB,DIV MATH & COMP SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 10 TC 26 Z9 26 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-1119 J9 GENE JI Gene PD MAY 20 PY 1997 VL 191 IS 1 BP GC1 EP GC9 DI 10.1016/S0378-1119(96)00854-2 PG 9 WC Genetics & Heredity SC Genetics & Heredity GA XF373 UT WOS:A1997XF37300020 PM 9210599 ER PT J AU Zang, J Birman, JL Bishop, AR Wang, L AF Zang, J Birman, JL Bishop, AR Wang, L TI Nonequilibrium transport and population inversion in double quantum dot systems SO INTERNATIONAL JOURNAL OF MODERN PHYSICS B LA English DT Article ID CONDUCTANCE OSCILLATIONS; COHERENT TRANSPORT; ANDERSON IMPURITY; COULOMB-BLOCKADE; SPECTROSCOPY; MODEL; LASER AB We present a microscopic theory for both equilibrium and nonequilibrium transport properties of coupled double quantum dots (DQD). A general formula for current tunneling through the DQD is derived by the nonequilibrium Green's function method. Using a Hartree-Fock approach, effects of multi-level coupling and nonequilibrium electron distributions in resonant tunneling are considered. We iind that the peak in the resonant tunneling current through two symmetric dots will split only when the inter-dot coupling is stronger than dot-lead coupling. We predict that population inversion can be achieved in one dot in the nonequilibrium regime. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. CUNY CITY COLL,DEPT PHYS,NEW YORK,NY 10031. RP Zang, J (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 29 TC 2 Z9 2 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-9792 J9 INT J MOD PHYS B JI Int. J. Mod. Phys. B PD MAY 20 PY 1997 VL 11 IS 12 BP 1463 EP 1475 DI 10.1142/S0217979297000745 PG 13 WC Physics, Applied; Physics, Condensed Matter; Physics, Mathematical SC Physics GA WX522 UT WOS:A1997WX52200003 ER PT J AU Vorderwisch, P Hautecler, S Eckert, J AF Vorderwisch, P Hautecler, S Eckert, J TI Neutron spectroscopy of localized modes in CeD2-xHy SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE neutron scattering; crystal structure; localized modes ID DYNAMICS; CED2.12 AB Localized modes of H in CeD1.93H0.07 and CeD2.00H0.07 have been measured by inelastic neutron scattering. Assignment of the observed peak positions and intensities in the measured spectra was obtained with a lattice dynamical treatment of an extended ''supercell'', modelling the crystal structure of the samples. C1 LOS ALAMOS NATL LAB,MLNSC,LOS ALAMOS,NM 87545. RP Vorderwisch, P (reprint author), HAHN MEITNER INST BERLIN GMBH,BENSC,GLIENICKER STR 100,D-14109 BERLIN,GERMANY. NR 8 TC 1 Z9 1 U1 0 U2 0 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 MAY 20 PY 1997 VL 253 BP 252 EP 254 DI 10.1016/S0925-8388(96)03084-8 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900059 ER PT J AU Birnbaum, HK Buckley, C Zeides, F Sirois, E Rozenak, P Spooner, S Lin, JS AF Birnbaum, HK Buckley, C Zeides, F Sirois, E Rozenak, P Spooner, S Lin, JS TI Hydrogen in aluminum SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE aluminum; hydrogen; vacancies; small angle scattering; hydrogen-vacancy complex ID METALS; DIFFUSION AB The introduction of solute hydrogen in high purity aluminum has been studied using a variety of experimental techniques. Very large hydrogen concentrations were introduced by electrochemical charging and by chemical charging. Length change and lattice parameter measurements showed that the hydrogen was trapped at vacancies which entered in a ratio close to C-v/C-H=1. Small angle X-ray scattering showed that the hydrogen-vacancy complexes clustered into platelets lying on the {111}. C1 OAK RIDGE NATL LAB,DIV MET & CERAM,OAK RIDGE,TN. RP Birnbaum, HK (reprint author), UNIV ILLINOIS,MAT RES LAB,URBANA,IL 61801, USA. RI Buckley, Craig/B-6753-2013 OI Buckley, Craig/0000-0002-3075-1863 NR 22 TC 110 Z9 112 U1 1 U2 17 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 MAY 20 PY 1997 VL 253 BP 260 EP 264 DI 10.1016/S0925-8388(96)02968-4 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900062 ER PT J AU Gingl, F Yvon, K Vogt, T Hewat, A AF Gingl, F Yvon, K Vogt, T Hewat, A TI Synthesis and crystal structure of tetragonal LnMg(2)H(7) (Ln=La, Ce), two Laves phase hydride derivatives having ordered hydrogen distribution SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE Laves phasecrystal structure; neutron diffraction; hydrogen ordering ID SYSTEMS AB LaMg2H7, CeMg2H7 and their deuterides were synthesized by hydrogenation (deuteration) of binary LnMg(2) at 373 K (Ln=La) and 423 K (Ln=Ce) and 100 bar hydrogen (deuterium) pressure and characterized by X-ray and neutron powder diffraction at room temperature. Their metal substructure represents a new tetragonal distortion variant of the cubic C15 Laves phase structure, space group P4(i)2(1)2 (No. 92); cell parameters for LaMg2H7: a=6.4054(2) Angstrom, c=9.5994(3) Angstrom; LaMg2D7: a=6.3900(2) Angstrom, c=9.5782(4) Angstrom; CeMg2H7: a=6.3663(3) Angstrom, c=9.5226(5) Angstrom; CeMg2D7: a=6.3501(3) Angstrom, c=9.4957(5) Angstrom; Z=4. The hydrogen (deuterium) distribution consists of four symmetry independent, fully occupied sites having triangular [Ln(2)Mg] and tetrahedral [Ln(2)Mg(2)] and [Mg-4] metal coordinations with distances in the range La-D=2.39-2.55 Angstrom; Ce-D=2.36-2.51 Angstrom; Mg-D=1.92-2.13 A (La), 1.91-2.18 Angstrom (Ce). The hydrogen-to-metal ratio, H/M=7/3, is the highest reported so far for Laves phase hydride derivatives. C1 UNIV GENEVA,LAB CRISTALLOG,CH-1211 GENEVA 4,SWITZERLAND. BROOKHAVEN NATL LAB,DEPT PHYS,UPTON,NY 11973. INST MAX VON LAUE PAUL LANGEVIN,F-38042 GRENOBLE 9,FRANCE. RI Vogt, Thomas /A-1562-2011 OI Vogt, Thomas /0000-0002-4731-2787 NR 15 TC 28 Z9 31 U1 1 U2 2 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 MAY 20 PY 1997 VL 253 BP 313 EP 317 DI 10.1016/S0925-8388(96)02992-1 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900075 ER PT J AU Kappesser, B Wipf, H Barnes, RG Beaudry, BJ AF Kappesser, B Wipf, H Barnes, RG Beaudry, BJ TI A study of hydrogen diffusion in hexagonal YHx single crystals (x<=0.10) mechanical spectroscopy SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE metal-hydrogen systems; hydrogen diffusion in metals; mechanical spectroscopy; internal friction; Zener relaxation ID ULTRASONIC MEASUREMENTS; Y-H; RELAXATION; YTTRIUM; MOTION; SYSTEM; LU AB We studied the diffusion of H in hcp YHx single crystals (x less than or equal to 0.1), by mechanical spectroscopy (vibrating-reed technique, 280 to 1750 Hz). In agreement with previous data from polycrystalline YH2, we find an anelastic relaxation peak at similar to 280 K. Our single crystals show a large anisotropy in the relaxation strength which demonstrates that this peak results from a Zener relaxation of H pairs. Two types of H jumps determine the relaxation kinetics. Comparison with previous quasielastic neutron scattering data identifies the jumps that cause the relaxation, showing further that their jump rates follow, over ten orders of magnitude, an Arrhenius law with an activation energy of(0.60 +/- 0.03) eV. C1 TH DARMSTADT,INST FESTKORPERPHYS,D-64289 DARMSTADT,GERMANY. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. NR 17 TC 9 Z9 9 U1 1 U2 2 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 MAY 20 PY 1997 VL 253 BP 386 EP 389 DI 10.1016/S0925-8388(96)02971-4 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900095 ER PT J AU Stoll, M Kaess, U Majer, G Barnes, RG AF Stoll, M Kaess, U Majer, G Barnes, RG TI Nuclear magnetic resonance studies of hydrogen diffusion in the layer-structured system ZrClHx SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE transition-metal halide hydride; two-dimensional diffusion; spin-lattice relaxation; PFG-NMR ID SPIN-LATTICE-RELAXATION; TRANSLATIONAL DIFFUSION; ZIRCONIUM MONOCHLORIDE; HIGH-FREQUENCY; DIFFRACTION; DIHYDRIDES; HYDRIDES; PHASES; SOLIDS AB The proton spin-lattice relaxation rate Gamma(1) in ZrClH0.5 shows one maximum and two shoulders, which indicates three distinct modes of hydrogen motion. The frequency dependence of the spin-lattice relaxation rate in the rotating frame, Gamma(1,rho), shows clearly that hydrogen diffusion is confined to two dimensions. Direct measurements of the long-range diffusivity D-xy were performed by pulsed field gradient (PFG) spin-echo NMR. These PFG experiments confirmed the two-dimensional character of hydrogen diffusion. The temperature dependence of D-xy yields an activation enthalpy, H-a=0.49 eV, which is in good agreement with the value H-a=0.47 eV deduced from the frequency-dependent Gamma(1,rho) data. The different processes of hydrogen motion are discussed on an atomistic scale. The Gamma(1) and Gamma(1,rho) curves measured in ZrClH1.0 are consistent with a single mechanism of hydrogen diffusion. Both the relaxation data and the PFG data reveal a strongly reduced hydrogen mobility in ZrClH1.0 compared to ZrClH0.5. From the analysis of the echo amplitude in the PFC experiments it is concluded that the hydrogen diffusion is restricted to two dimensions as well. The D-xy values show Arrhenius behavior with an activation enthalpy of H-a=0.58 eV. C1 MAX PLANCK INST MED RES,INST PHYS,D-70569 STUTTGART,GERMANY. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. NR 27 TC 1 Z9 1 U1 0 U2 1 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 MAY 20 PY 1997 VL 253 BP 435 EP 440 DI 10.1016/S0925-8388(96)03080-0 PG 6 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900107 ER PT J AU JeroschHerold, M Torgeson, DR Barnes, RG AF JeroschHerold, M Torgeson, DR Barnes, RG TI Systematics of the anomalous high-temperature Sc-45 spin-lattice relaxation in scandium hydrides and deuterides SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE scandium hydrides (deuterides); nuclear magnetic resonance; high-temperature; vacancy-interstitial clusters ID HYDROGEN-DIFFUSION; NUCLEAR AB The nuclear magnetic resonance of the metal nucleus Sc-45 shows anomalous spin-lattice relaxation at high temperatures (T greater than or equal to 800 K) in scandium dihydride and dideuteride. The anomalous rate R-1A is represented by R-1A=Aexp(-U/k(B)T), with an effective excitation enthalpy U and strength A. U increases sharply with decreasing H(D) vacancy concentration as [H(D)]/[Sc]-->2.00. These new measurements and analysis support the concept of stable clusters of interacting thermally excited H(D) Frenkel interstitials and vacancies in fluorite-structure dihydrides and dideuterides. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. UNIV MINNESOTA,DEPT RADIOL,MINNEAPOLIS,MN 55455. NR 8 TC 2 Z9 2 U1 1 U2 1 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 MAY 20 PY 1997 VL 253 BP 441 EP 444 DI 10.1016/S0925-8388(96)02944-1 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900108 ER PT J AU Barnes, RG Beaudry, BJ Torgeson, DR Chang, CT Creel, RB AF Barnes, RG Beaudry, BJ Torgeson, DR Chang, CT Creel, RB TI Hydrogen hopping rates and the order-disorder transitions in sub-stoichiometric lanthanum trihydride SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE lanthanum trihydride; order-disorder transition; nuclear magnetic resonance ID ELECTRONIC-STRUCTURE; HYDRIDES AB Extensive measurements of proton magnetic resonance lineshapes and spin-lattice relaxation rates in sub-stoichiometric lanthanum trihydrides, prepared from highest purity La metal, furnish clear evidence for the coexistence of ordered and disordered hydrogen sublattices over an extended temperature range terminating with the onset of semiconducting behavior. This phenomenon persists even at the stoichiometric limit, LaH3. Analysis of resonance lineshape intensities yields H-t=0.080+/-0.020 eV for the enthalpy of the order-disorder transition in LaH2.99, and analysis of intensities in relaxation rate measurements yields H-t=0.066+/-0.020 eV for this enthalpy in LaH2.90. A second, higher temperature transition in the hydrogen hopping rate appears to coincide with the onset of semiconducting behavior. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS,AMES,IA 50011. TEXAS A&M UNIV,MR IMAGING LAB,COLLEGE STN,TX 77843. UNIV AKRON,DEPT PHYS,AKRON,OH 44325. RP Barnes, RG (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011, USA. NR 14 TC 10 Z9 10 U1 1 U2 1 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 MAY 20 PY 1997 VL 253 BP 445 EP 448 DI 10.1016/S0925-8388(96)02969-6 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900109 ER PT J AU Barnes, RG Cameron, LM JeroschHerold, M Scholl, CA AF Barnes, RG Cameron, LM JeroschHerold, M Scholl, CA TI Nuclear quadrupolar relaxation in metal-hydrogen systems SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE metal; hydrogen; nuclear quadrupole relaxation ID TRANSLATIONAL DIFFUSION; SOLIDS AB The theory of nuclear spin relaxation of quadrupolar metal nuclei is considered for the ScH(D)(x) system for arbitrary values of concentration c=x/2 of the diffusing H(D). It is shown that the relaxation rates simply scale in magnitude as c(1-c) and that the temperature dependence is independent of c. C1 UNIV NEW ENGLAND,DEPT PHYS,ARMIDALE,NSW 2351,AUSTRALIA. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DOE,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,DEPT PHYS,AMES,IA 50011. UNIV MINNESOTA,DEPT RADIOL,MINNEAPOLIS,MN 55455. NR 7 TC 2 Z9 2 U1 0 U2 0 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 MAY 20 PY 1997 VL 253 BP 449 EP 451 DI 10.1016/S0925-8388(96)03081-2 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900110 ER PT J AU Adzic, GD Johnson, JR Mukerjee, S McBreen, J Reilly, JJ AF Adzic, GD Johnson, JR Mukerjee, S McBreen, J Reilly, JJ TI Function of cobalt in AB(5)H(x) electrodes SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE metal hydride electrodes; AB(5) ID HYDRIDE ELECTRODES; ALLOY ELECTRODES AB The role of cobalt in the behavior of AB(5)H(x) electrodes has been investigated. Alloy compositions were as follows, LaNi4.3-x CoxMn0.4Al0.3 (x=0, 0.2, 0.4, 0.75) and MmNi(4.3-x)Co(x)Mn(0.4)Al(0.3) (x=0, 0.75). Cobalt was found to decrease the molar volume of hydrogen V-H, in the hydride phase. Both LaNi4.3-xCoxMn0.4Al0.3 and MmNi(4.3-x)Co(x)Mn(0.4)Al(0.3) alloy electrodes were subjected to repeated electrochemical cycling and corrosion rates measured. The corrosion rate was found to be inversely proportional to the cobalt content of the electrode. RP Adzic, GD (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973, USA. NR 7 TC 66 Z9 70 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 MAY 20 PY 1997 VL 253 BP 579 EP 582 DI 10.1016/S0925-8388(96)02988-X PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900136 ER PT J AU Bowman, RC Witham, C Fultz, B Ratnakumar, BV Ellis, TW Anderson, IE AF Bowman, RC Witham, C Fultz, B Ratnakumar, BV Ellis, TW Anderson, IE TI Hydriding behavior of gas-atomized AB(5) alloys SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article; Proceedings Paper CT International Symposium on Metal Hydrogen Systems: Fundamentals and Applications CY AUG 25-30, 1996 CL LES DIABLERETS, SWITZERLAND DE metal hydrides; gas atomization; electrochemical hydride properties; hydrogen storage alloys; Ni-MH battery alloys; LaNi5 ID HYDROGEN STORAGE ALLOYS; DEGRADATION; LANI5 AB The hydriding characteristics of some AB(5) alloys produced by high pressure gas atomization (HPGA) have been examined during reactions with hydrogen gas, and in electrochemical cells. The hydrogen storage capacities and the equilibrium pressures for HPGA processed LaNi5, LaNi4.75Sn0.25, and MmNi(3.5)Co(0.8)Al(0.4)Mn(0.3) alloys (where Mm denotes Mischmetal) are found to be nearly identical to annealed alloys produced as ingots. The large discontinuous volume change across the alpha-beta plateau region for gas-atomized LaNi5Hx was seen to produce extensive fracturing in all but the smallest alloy spheres. However, only the largest spheres of the gas-atomized MmNi(3.5)Co(0.8)Al(0.4)Mn(0.3) and LaNi4.75Sn0.25Hx alloys exhibited any discernible fracturing. The maximum electrochemical storage capacities of the gas-atomized LaNi4.75Sn0.25 and MmNi(3.5)Co(0.8)Al(0.4)Mn(0.3) alloys were found to be smaller than the capacities of annealed alloys prepared from ingots. C1 CALTECH,JET PROP LAB,ELECTROCHEM TECHNOL PROGRAM,PASADENA,CA 91109. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. RP Bowman, RC (reprint author), CALTECH,DIV ENGN & APPL SCI,PASADENA,CA 91125, USA. OI Bowman, Robert/0000-0002-2114-1713 NR 10 TC 28 Z9 30 U1 0 U2 1 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 MAY 20 PY 1997 VL 253 BP 613 EP 616 DI 10.1016/S0925-8388(96)02929-5 PG 4 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XJ169 UT WOS:A1997XJ16900145 ER PT J AU Ropars, G Langot, P Brunel, M Vallet, M Bretenaker, F LeFloch, A Choquette, KD AF Ropars, G Langot, P Brunel, M Vallet, M Bretenaker, F LeFloch, A Choquette, KD TI Experimental evidence of single round-trip oscillation in polarization self-modulated vertical-cavity surface emitting lasers SO APPLIED PHYSICS LETTERS LA English DT Article ID EXTERNAL OPTICAL FEEDBACK; SPECTRAL CHARACTERISTICS AB The polarizations and frequencies of the two eigenstates of a vertical cavity surface emitting laser with an external cavity containing a quarter-wave plate are theoretically and experimentally analyzed. It is shown that the polarizations of these eigenstates are fixed by the neutral axes of the quarter-wave plate. The optical pulses at a frequency equal to a half of the free spectral range of the external cavity, observed through a linear polarizer, are due to beats between the two eigenstates. All these features show that such polarization self-modulated lasers oscillate in a single round trip. (C) 1997 American Institute of Physics. C1 SANDIA NATL LABS,CTR COMPOUND SEMICOND TECHNOL,ALBUQUERQUE,NM 87185. RP Ropars, G (reprint author), UNIV RENNES 1,LAB ELECT QUANT PHYS LASERS,UMR CNRS 6627,CAMPUS BEAULIEU,F-35042 RENNES,FRANCE. RI Bretenaker, Fabien/C-1814-2012 NR 10 TC 22 Z9 22 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 19 PY 1997 VL 70 IS 20 BP 2661 EP 2663 DI 10.1063/1.118982 PG 3 WC Physics, Applied SC Physics GA WZ348 UT WOS:A1997WZ34800008 ER PT J AU LawniczakJablonska, K Suski, T LilientalWeber, Z Gullikson, EM Underwood, JH Perera, RCC Drummond, TJ AF LawniczakJablonska, K Suski, T LilientalWeber, Z Gullikson, EM Underwood, JH Perera, RCC Drummond, TJ TI Anisotropy of the nitrogen conduction states in the group III nitrides studied by polarized x-ray absorption SO APPLIED PHYSICS LETTERS LA English DT Article ID GAN; ALN AB The energy distribution of the nitrogen antibonding electron states in the hexagonal epitaxial layers of AlN, GaN, and InN and cubic epitaxial layers of GaN and InN along p(xy) plane and p(z) direction is reported. The study was performed by the polarized x-ray absorption at the K edge of N. A strong polarization dependence of the absorption spectra indicating the significant anisotropy of the conduction band was found in the case of hexagonal samples. Very weak polarization dependencies observed in cubic samples correspond well with the defect distribution anisotropy. Qualitatively different and cation dependent antibonding states distribution point out the role played by a contribution of hybridized cation-nitrogen electronic states to the individual conduction bandstructures of AlN, GaN, and InN. (C) 1997 American Institute of Physics. C1 POLISH ACAD SCI,INST PHYS,PL-02668 WARSAW,POLAND. POLISH ACAD SCI,HIGH PRESSURE RES CTR,PL-01142 WARSAW,POLAND. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP LawniczakJablonska, K (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Lawniczak-Jablonska, Krystyna/J-8994-2012 OI Lawniczak-Jablonska, Krystyna/0000-0003-1042-570X NR 7 TC 38 Z9 38 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 19 PY 1997 VL 70 IS 20 BP 2711 EP 2713 DI 10.1063/1.119000 PG 3 WC Physics, Applied SC Physics GA WZ348 UT WOS:A1997WZ34800025 ER PT J AU Zolper, JC Tan, HH Williams, JS Zou, J Cockayne, DJH Pearton, SJ Crawford, MH Karlicek, RF AF Zolper, JC Tan, HH Williams, JS Zou, J Cockayne, DJH Pearton, SJ Crawford, MH Karlicek, RF TI Electrical and structural analysis of high-dose Si implantation in GaN SO APPLIED PHYSICS LETTERS LA English DT Article AB For the development of ion implantation processes for GaN to advanced devices, it is important to understand the dose dependence of impurity activation along with implantation-induced damage generation and removal. We find that Si implantation in GaN can achieve 50% activation at a dose of 1x10(16) cm(-2), despite significant residual damage after the 1100 degrees C activation anneal. The possibility that the generated free carriers are due to implantation damage alone and not Si-donor activation is ruled out by comparing the Si results to those for implantation of the neutral species Ar. Ion channeling and cross-sectional transmission electron microscopy are used to characterize the implantation-induced damage both as implanted and after a 1100 degrees C anneal. Both techniques confirm that significant damage remains after the anneal, which suggests that activation of implanted Si donors in GaN doses not require complete damage removal. However, an improved annealing process may be needed to further optimize the transport properties of implanted regions in GaN. (C) 1997 American Institute of Physics. C1 AUSTRALIAN NATL UNIV, RES SCH PHYS SCI & ENGN, DEPT ELECT MAT & ENGN, CANBERRA, ACT 0200, AUSTRALIA. UNIV SYDNEY, ELECTRON MICROSCOPE UNIT, SYDNEY, NSW 2006, AUSTRALIA. UNIV SYDNEY, AUSTRALIAN KEY CTR MICROSCOPY & MICROANAL, SYDNEY, NSW 2006, AUSTRALIA. UNIV FLORIDA, DEPT MAT SCI & ENGN, GAINESVILLE, FL 32611 USA. EMCORE CORP, SOMERSET, NJ 08873 USA. RP Zolper, JC (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. RI Zou, Jin/B-3183-2009; Tan, Hark Hoe/M-1148-2015 OI Zou, Jin/0000-0001-9435-8043; Tan, Hark Hoe/0000-0002-7816-537X NR 16 TC 85 Z9 87 U1 1 U2 5 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 19 PY 1997 VL 70 IS 20 BP 2729 EP 2731 DI 10.1063/1.119254 PG 3 WC Physics, Applied SC Physics GA WZ348 UT WOS:A1997WZ34800031 ER PT J AU Li, F Tang, H Shinar, J Resto, O Weisz, SZ AF Li, F Tang, H Shinar, J Resto, O Weisz, SZ TI Effects of aquaregia treatment of indium-tin-oxide substrates on the behavior of double layered organic light-emitting diodes SO APPLIED PHYSICS LETTERS LA English DT Article ID POLYMERS AB The effects of a controlled aquaregia treatment of indium-tin-oxide (ITO) substrates on the behavior of highly efficient Vacuum evaporated double layered 8-tris-hydroxyquinoline Al (Alq(3))-based light-emitting diodes are described. It is found that in suitably treated devices, both current injection and the electroluminescence (EL) are significantly enhanced. The enhancement is believed to result from the greater ITO/hole transporting layer contact areas and the contact conditions. The observed dependence of I(V), the EL output, and the EL efficiency on the ITO surface morphology indicates that space-charge-limited currents dominate the behavior of the devices. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV PUERTO RICO,DEPT PHYS,RIO PIEDRAS,PR 00931. UNIV PUERTO RICO,CTR MAT RES,RIO PIEDRAS,PR 00931. RP Li, F (reprint author), IOWA STATE UNIV,US DOE,AMES LAB,AMES,IA 50011, USA. NR 11 TC 148 Z9 153 U1 3 U2 13 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 MAY 19 PY 1997 VL 70 IS 20 BP 2741 EP 2743 DI 10.1063/1.119008 PG 3 WC Physics, Applied SC Physics GA WZ348 UT WOS:A1997WZ34800035 ER PT J AU Hoberg, JO AF Hoberg, JO TI Synthesis and chemistry of 4,6-O-di-(tert-butyl)silanediyl-D-glucal SO CARBOHYDRATE RESEARCH LA English DT Article DE 4,6-O-di-(tert-butyl)silanediyl-D-glucal; protection; di-tert-butylsilyl ditriflate; D-glucal ID ALLYLTRIMETHYLSILANE RP Hoberg, JO (reprint author), NATL RENEWABLE ENERGY LAB,1617 COLE BLVD,GOLDEN,CO 80401, USA. NR 14 TC 29 Z9 29 U1 1 U2 2 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0008-6215 J9 CARBOHYD RES JI Carbohydr. Res. PD MAY 19 PY 1997 VL 300 IS 4 BP 365 EP 367 DI 10.1016/S0008-6215(97)00068-2 PG 3 WC Biochemistry & Molecular Biology; Chemistry, Applied; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA XC864 UT WOS:A1997XC86400011 ER PT J AU Dorey, N Khoze, VV Mattis, MP AF Dorey, N Khoze, VV Mattis, MP TI On N=2 supersymmetric QCD with four flavors SO NUCLEAR PHYSICS B LA English DT Article DE N = 2 supersymmetric QCD; instantons ID EFFECTIVE GAUGE-THEORIES; DEPENDENCE; REGULARIZATION; DUALITY AB Seiberg and Witten's proposed solution of N=2 SQCD with N-c=2 and N-F=3 is known to conflict with instanton calculations in three distinct ways, Here we show how to resolve all three discrepancies, simply by reparametrizing the elliptic curve in terms of quantities tau(eff)((0)) and <(mu)over tilde> rather than tau and u=(Tr<(A)under tilde(2)>). SL(2, Z) invariance of the curve is preserved. However, there is now an infinite ambiguity in the relation between tau(eff)((0)) and tau and between <(mu)over tilde> and u, corresponding to an infinite number of unknown coefficients in the instanton expansion, Thus the reinterpreted curve (unlike the cases N-F <4) no longer determines the quantum modulus II as a function of the classical VEV a. (C) 1997 Elsevier Science B.V. C1 UNIV DURHAM, CTR PARTICLE THEORY, DEPT PHYS, DURHAM DH1 3LE, ENGLAND. LOS ALAMOS NATL LAB, DIV THEORET, LOS ALAMOS, NM 87545 USA. RP Dorey, N (reprint author), UNIV COLL SWANSEA, DEPT PHYS, SWANSEA SA2 8PP, W GLAM, WALES. OI Khoze, Valentin V/0000-0003-3006-4147 NR 30 TC 48 Z9 48 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 19 PY 1997 VL 492 IS 3 BP 607 EP 622 DI 10.1016/S0550-3213(97)00132-6 PG 16 WC Physics, Particles & Fields SC Physics GA XA256 UT WOS:A1997XA25600003 ER PT J AU Schweigert, C AF Schweigert, C TI On moduli spaces of flat connections with non-simply connected structure group SO NUCLEAR PHYSICS B LA English DT Article DE moduli spaces; flat connections; WZW models; Chem-Simons theories ID QUANTIZATION AB We consider the moduli space of flat G-bundles over the two-dimensional torus, where G is a real, compact, simple Lie group which is not simply connected, We show that the connected components that describe topologically non-trivial bundles are isomorphic as symplectic spaces to moduli spaces of topologically trivial bundles with a different structure group, Some physical applications of this isomorphism which allows one to trade topological non-triviality for a change of the gauge group are sketched. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP Schweigert, C (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. OI Schweigert, Christoph/0000-0003-1342-6230 NR 10 TC 25 Z9 27 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 19 PY 1997 VL 492 IS 3 BP 743 EP 755 DI 10.1016/S0550-3213(97)00152-1 PG 13 WC Physics, Particles & Fields SC Physics GA XA256 UT WOS:A1997XA25600008 ER PT J AU Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amidi, E Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K DelSignore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY JoffeMinor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Singh, P Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amidi, E Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K DelSignore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Gomez, G Goncharov, PI Solis, JLG Gordon, H Goss, LT Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY JoffeMinor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Singh, P Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Search for a fourth generation charge -1/3 quark via flavor changing neutral current decay SO PHYSICAL REVIEW LETTERS LA English DT Article ID PRODUCTION CROSS-SECTION; FERMION FAMILIES; HEAVY QUARKS; Z0; PHOTONS; TRISTAN; LEPTONS; MODEL; LEP AB We report on a search for pair production of a fourth generation charge -1/3 quark (b') in p (n) over bar collisions at root s = 1.8 TeV by the DO experiment at the Fermilab Tevatron using an integrated luminosity of 93 pb(-1). Both b' quarks are assumed to decay via flavor changing neutral currents (FCNC). The search uses the signatures gamma + 3 jets mu-tag and 2 gamma + 2 jets. We see no significant excess of events over the expected background. We place an upper limit on the production cross section times branching fraction that is well below theoretical expectations for a bl decaying exclusively via FCNC for b' masses up to m(Z) + m(b). C1 UNIV LOS ANDES,BOGOTA,COLOMBIA. UNIV ARIZONA,TUCSON,AZ 85721. BOSTON UNIV,BOSTON,MA 02215. BROOKHAVEN NATL LAB,UPTON,NY 11973. BROWN UNIV,PROVIDENCE,RI 02912. UNIV BUENOS AIRES,BUENOS AIRES,DF,ARGENTINA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF IRVINE,IRVINE,CA 92717. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. CTR BRASILEIRO PESQUISAS FIS,LAFEX,RIO JANEIRO,BRAZIL. CINVESTAV IPN,MEXICO CITY 14000,DF,MEXICO. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV DELHI,DELHI 110007,INDIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV HAWAII,HONOLULU,HI 96822. UNIV CHICAGO,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. IOWA STATE UNIV SCI & TECHNOL,AMES,IA 50011. KOREA UNIV,SEOUL 136701,SOUTH KOREA. KYUNGSUNG UNIV,PUSAN 608736,SOUTH KOREA. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. UNIV NEBRASKA,LINCOLN,NE 68588. NYU,NEW YORK,NY 10003. NORTHEASTERN UNIV,BOSTON,MA 02115. NO ILLINOIS UNIV,DE KALB,IL 60115. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV OKLAHOMA,NORMAN,OK 73019. PANJAB UNIV,CHANDIGARH 160014,INDIA. PROTVINO HIGH ENERGY PHYS INST,PROTVINO 142284,RUSSIA. PURDUE UNIV,W LAFAYETTE,IN 47907. RICE UNIV,HOUSTON,TX 77005. UNIV ESTADUAL RIO DE JANEIRO,RIO JANEIRO,BRAZIL. UNIV ROCHESTER,ROCHESTER,NY 14627. CENS,SERV PHYS PARTICULES,DAPNIA,CEA,GIF SUR YVETTE,FRANCE. SEOUL NATL UNIV,SEOUL,SOUTH KOREA. SUNY STONY BROOK,STONY BROOK,NY 11794. TATA INST FUNDAMENTAL RES,BOMBAY 400005,MAHARASHTRA,INDIA. UNIV TEXAS,ARLINGTON,TX 76019. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Abachi, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Klyukhin, Vyacheslav/D-6850-2012; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013 OI Sznajder, Andre/0000-0001-6998-1108; Baarmand, Marc/0000-0002-9792-8619; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Aihara, Hiroaki/0000-0002-1907-5964; Dudko, Lev/0000-0002-4462-3192; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; NR 29 TC 26 Z9 26 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 19 PY 1997 VL 78 IS 20 BP 3818 EP 3823 DI 10.1103/PhysRevLett.78.3818 PG 6 WC Physics, Multidisciplinary SC Physics GA WZ244 UT WOS:A1997WZ24400005 ER PT J AU Zhang, J MacPhee, AG Nilsen, J Lin, J Barbee, TW Danson, C Key, MH Lewis, CLS Neely, D ORourke, RMN Pert, GJ Smith, R Tallents, GJ Wark, JS Wolfrum, E AF Zhang, J MacPhee, AG Nilsen, J Lin, J Barbee, TW Danson, C Key, MH Lewis, CLS Neely, D ORourke, RMN Pert, GJ Smith, R Tallents, GJ Wark, JS Wolfrum, E TI Demonstration of saturation in a Ni-like Ag x-ray laser at 14 nm SO PHYSICAL REVIEW LETTERS LA English DT Article ID XUV LASER; HIGH-GAIN AB We report the first demonstration of saturation in a Ni-like x-ray laser, specifically Ni-like Ag x-ray laser at 14 nm. Using high-resolution spatial imaging and angularly resolved streaking techniques, the output source size as well as the time history, divergence, energy, and spatial profile of the output beam have been fully characterized. The output intensity of the Ag laser was measured to be about 70 GWcm(-2) The narrow divergence, short pulse duration, high efficiency, and high brightness of the Ag laser make it an ideal candidate for many x-ray laser applications. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. QUEENS UNIV BELFAST,SCH MATH & PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. RP Zhang, J (reprint author), RUTHERFORD APPLETON LAB,CENT LASER FACIL,DIDCOT OX11 0QX,OXON,ENGLAND. RI Zhang, Jie/O-8767-2014 NR 27 TC 137 Z9 153 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 19 PY 1997 VL 78 IS 20 BP 3856 EP 3859 DI 10.1103/PhysRevLett.78.3856 PG 4 WC Physics, Multidisciplinary SC Physics GA WZ244 UT WOS:A1997WZ24400014 ER PT J AU Hsing, WW Hoffman, NM AF Hsing, WW Hoffman, NM TI Measurement of feedthrough and instability growth in radiation-driven cylindrical implosions SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; HYDRODYNAMIC INSTABILITY; TARGETS; NOVA; FUSION; SIMULATIONS; SATURATION; STABILITY; PLASMA; RATES AB We have performed the first radiation-driven implosions in a convergent geometry where feedthrough of the Rayleigh-Taylor instability and Bell-Plesset growth are observed. A perturbation in a dodecagon shape was machined on the outer surface of a cylindrical polystyrene shell. The shell was imploded by radiation ablation in a hohlraum at the Nova laser. Growth of the perturbation was observed at the inner surface of the shell via x-ray backlighter imaging. This method shows promise for the study of instability growth and feedthrough in converging flows. RP Hsing, WW (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 41 TC 31 Z9 33 U1 1 U2 6 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 19 PY 1997 VL 78 IS 20 BP 3876 EP 3879 DI 10.1103/PhysRevLett.78.3876 PG 4 WC Physics, Multidisciplinary SC Physics GA WZ244 UT WOS:A1997WZ24400019 ER PT J AU Voter, AF AF Voter, AF TI Hyperdynamics: Accelerated molecular dynamics of infrequent events SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACE SELF-DIFFUSION; MECHANISM; CLUSTERS; AL; NI AB I derive a general method for accelerating the molecular-dynamics (MD) simulation of infrequent events in solids. A bias potential (Delta V-b) raises the energy in regions other than the transition states b between potential basins. Transitions occur at an accelerated rate and the elapsed time becomes a statistical property of the system. Delta V-b can be constructed without knowing the location of the transition states and implementation requires only first derivatives. I examine the diffusion mechanisms of a 10-atom Ag cluster on the Ag(111) surface using a 220 mu s hyper-MD simulation. RP Voter, AF (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. OI Voter, Arthur/0000-0001-9788-7194 NR 17 TC 529 Z9 533 U1 11 U2 89 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 19 PY 1997 VL 78 IS 20 BP 3908 EP 3911 DI 10.1103/PhysRevLett.78.3908 PG 4 WC Physics, Multidisciplinary SC Physics GA WZ244 UT WOS:A1997WZ24400027 ER PT J AU Wetzel, C Suski, T Ager, JW Weber, ER Haller, EE Fischer, S Meyer, BK Molnar, RJ Perlin, P AF Wetzel, C Suski, T Ager, JW Weber, ER Haller, EE Fischer, S Meyer, BK Molnar, RJ Perlin, P TI Pressure induced deep gap state of oxygen in GaN SO PHYSICAL REVIEW LETTERS LA English DT Article ID GALLIUM NITRIDE; HYDROSTATIC-PRESSURE; ELECTRONIC-STRUCTURE; ALXGA1-XAS ALLOYS; NATIVE DEFECTS; DX-CENTER; GAAS AB O and Si donors in GaN are studied by Raman spectroscopy under hydrostatic pressure p. The ground state of O is found to transfer from a shallow level to a deep gap state at p >20 GPa reminiscent of DX centers in GaAs. Transferred to AlxGa1-xN we predict that O induces a deep gap state for x >0.40. In GaN:Si no such state is induced up to the highest pressure obtained (p=25 GPa) equivalent to x=0.56 in AlxGa1-xN and possibly higher. We attribute this distinction to the lattice sites of the dopants. O substituting for N is found to be the origin of high free electron concentration in bulk GaN crystals. C1 LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV CALIF BERKELEY,BERKELEY,CA 94720. UNIV GIESSEN,INST PHYS 1,D-35392 GIESSEN,GERMANY. MIT,LINCOLN LAB,DIV SOLID STATE,LEXINGTON,MA 02173. UNIV NEW MEXICO,CTR HIGH TECHNOL MAT,ALBUQUERQUE,NM 87131. RI Wetzel, Christian/O-4017-2014; OI Wetzel, Christian/0000-0002-6055-0990; Ager, Joel/0000-0001-9334-9751 NR 28 TC 180 Z9 184 U1 6 U2 38 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 19 PY 1997 VL 78 IS 20 BP 3923 EP 3926 DI 10.1103/PhysRevLett.78.3923 PG 4 WC Physics, Multidisciplinary SC Physics GA WZ244 UT WOS:A1997WZ24400031 ER PT J AU Miquel, C Paz, JP Zurek, WH AF Miquel, C Paz, JP Zurek, WH TI Quantum computation with phase drift errors SO PHYSICAL REVIEW LETTERS LA English DT Article AB We numerically simulate the evolution of an ion trap quantum computer made out of 18 ions subject to a sequence of nearly 15 000 laser pulses in order to find the prime factors of N=15. We analyze the effect of random and systematic phase drift errors arising from inaccuracies in the laser pulses which induce over (under) rotation of the quantum state. Simple analytic estimates of the tolerance for the quality of driving pulses are presented. We examine the use of watchdog stabilization to partially correct phase drift errors concluding that, in the regime investigated, it is rather inefficient. C1 UNIV BUENOS AIRES,FAC CIENCIAS EXACTAS & NAT,DEPT FIS JJ GIAMBIAGI,RA-1428 BUENOS AIRES,DF,ARGENTINA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. INST ASTRON & FIS ESPACIO,RA-1428 BUENOS AIRES,DF,ARGENTINA. RP Miquel, C (reprint author), UNIV CALIF SANTA BARBARA,INST THEORET PHYS,SANTA BARBARA,CA 93106, USA. RI Paz, Juan/C-5947-2008 NR 14 TC 52 Z9 52 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 19 PY 1997 VL 78 IS 20 BP 3971 EP 3974 DI 10.1103/PhysRevLett.78.3971 PG 4 WC Physics, Multidisciplinary SC Physics GA WZ244 UT WOS:A1997WZ24400043 ER PT J AU Tano, K Dunn, WC Darroudi, F Shiota, S Preston, RJ Natarajan, AT Mitra, S AF Tano, K Dunn, WC Darroudi, F Shiota, S Preston, RJ Natarajan, AT Mitra, S TI Amplification of the DNA repair gene O-6-methylguanine-DNA methyltransferase associated with resistance to alkylating drugs in a mammalian cell line SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID CHINESE-HAMSTER CELLS; O-6-ALKYLGUANINE-DNA ALKYLTRANSFERASE ACTIVITY; ESCHERICHIA-COLI; WILD-TYPE; EXPRESSION; PROTEIN; HYBRIDIZATION; INSIGHTS; AGENTS; ORIGIN AB The cytotoxic action of such alkylating chemotherapeutic drugs as 2-chloroethyl-N-nitrosourea (CNU) derivatives is countered by the repair protein O-6-methylguanine-DNA methyltransferase (MGMT), which removes O-6-alkylguanine induced in the DNA by these agents, Resistance to these drugs is often correlated with the MGMT levels in normal and tumor cells of human and rodent origin, Exposure of mouse 3T3 cells to increasing concentrations of CNU, and subsequent selection of resistant cells, led to the isolation of clones with 5-10 times higher levels of MGMT activity than in the control, The increased MGMT expression at both mRNA and protein levels resulted from 5- to 10-fold amplification of the Mgmt gene, Amplification of this gene was not associated with concomitant amplification of another alkylation damage repair gene, N-methylpurine-DNA glycosylase, No amplification of at least three other genes on chromosome 7 (which contains the Mgmt gene) was observed in the drug-resistant cells. Furthermore, the amplified Mgmt sequence was not associated with a homogeneously staining region, or double minute chromosomes, nor present as episomal DNA, In situ hybridization of metaphase chromosomes of the drug-resistant cells indicated both translocation and localized amplification of the Mgmt gene. C1 UNIV TEXAS,MED BRANCH,SEALY CTR MOL SCI,GALVESTON,TX 77555. OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. LEIDEN STATE UNIV,DEPT RADIAT GENET & CHEM MUTAGENESIS,NL-2333 AL LEIDEN,NETHERLANDS. FU NCI NIH HHS [CA31721]; NIEHS NIH HHS [ES06676, ES07572] NR 38 TC 19 Z9 20 U1 0 U2 0 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 MAY 16 PY 1997 VL 272 IS 20 BP 13250 EP 13254 DI 10.1074/jbc.272.20.13250 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WZ384 UT WOS:A1997WZ38400056 PM 9148943 ER PT J AU Barhen, J Protopopescu, V Reister, D AF Barhen, J Protopopescu, V Reister, D TI TRUST: A deterministic algorithm for global optimization SO SCIENCE LA English DT Article ID APPROXIMATION; STATICS AB An approach to solving continuous global optimization problems was developed. It builds on two innovative concepts, subenergy tunneling and non-Lipschitzian terminal repellers, to ensure escape from local minima in a fast, reliable, and computationally efficient manner. The generally applicable methodology is embodied in the TRUST (terminal repeller unconstrained subenergy tunneling) algorithm, which is deterministic, scalable, and easy to implement. Benchmark results show that TRUST is faster and more accurate than previously reported global optimization techniques. An application of TRUST to a large-scale exploratory seismology problem of substantial computational complexity (that is, residual statics corrections) is also reported. RP Barhen, J (reprint author), OAK RIDGE NATL LAB, CTR ENGN SYST ADV RES, OAK RIDGE, TN 37831 USA. NR 27 TC 121 Z9 127 U1 0 U2 10 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD MAY 16 PY 1997 VL 276 IS 5315 BP 1094 EP 1097 DI 10.1126/science.276.5315.1094 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ225 UT WOS:A1997WZ22500038 ER PT J AU Zhang, J MacPhee, AG Lin, J Wolfrum, E Smith, R Danson, C Key, MH Lewis, CLS Neely, D Nilsen, J Pert, GJ Tallents, GJ Wark, JS AF Zhang, J MacPhee, AG Lin, J Wolfrum, E Smith, R Danson, C Key, MH Lewis, CLS Neely, D Nilsen, J Pert, GJ Tallents, GJ Wark, JS TI A saturated X-ray laser beam at 7 nanometers SO SCIENCE LA English DT Article ID XUV LASER; NM; GAIN AB A saturated nickel-like samarium x-ray laser beam at 7 nanometers has been demonstrated with an output energy of 0.3 millijoule in 50-picosecond pulses, demonstrating that saturated operation of a laser at wavelengths shorter than 10 nanometers can be achieved. The narrow divergence, short wavelength, short pulse duration, high efficiency, and high brightness of this samarium laser make it an ideal candidate for many x-ray laser applications. C1 UNIV OXFORD,DEPT PHYS,CLARENDON LAB,OXFORD OX1 3PU,ENGLAND. QUEENS UNIV BELFAST,SCH MATH & PHYS,BELFAST BT7 1NN,ANTRIM,NORTH IRELAND. UNIV ESSEX,DEPT PHYS,COLCHESTER CO4 3SQ,ESSEX,ENGLAND. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV YORK,DEPT PHYS,YORK YO1 5DD,N YORKSHIRE,ENGLAND. RI Zhang, Jie/O-8767-2014 NR 27 TC 177 Z9 195 U1 0 U2 13 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 16 PY 1997 VL 276 IS 5315 BP 1097 EP 1100 DI 10.1126/science.276.5315.1097 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ225 UT WOS:A1997WZ22500039 ER PT J AU Mahal, LK Yarema, KJ Bertozzi, CR AF Mahal, LK Yarema, KJ Bertozzi, CR TI Engineering chemical reactivity on cell surfaces through oligosaccharide biosynthesis SO SCIENCE LA English DT Article ID N-ACETYLNEURAMINIC ACID; SIALIC-ACID; MONOCLONAL-ANTIBODIES; RICIN; MODULATION; PROTEINS; ALDOLASE; ANALOGS; VIRUS AB Cell surface oligosaccharides can be engineered to display unusual functional groups for the selective chemical remodeling of cell surfaces. An unnatural derivative of N-acetylmannosamine, which has a ketone group, was converted to the corresponding sialic acid and incorporated into cell surface oligosaccharides metabolically, resulting in the cell surface display of ketone groups. The ketone group on the cell surface can then be covalently ligated under physiological conditions with molecules carrying a complementary reactive functional group such as the hydrazide. Cell surface reactions of this kind should prove useful in the introduction of new recognition epitopes, such as peptides, oligosaccharides, or small organic molecules, onto cell surfaces and in the subsequent modulation of cell-cell or cell-small molecule binding events. The versatility of this technology was demonstrated by an example of selective drug delivery. Cells were decorated with biotin through selective conjugation to ketone groups, and selectively killed in the presence of a ricin A chain-avidin conjugate. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR ADV MAT,DIV SCI MAT,BERKELEY,CA 94720. RP Mahal, LK (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 25 TC 416 Z9 421 U1 11 U2 80 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 16 PY 1997 VL 276 IS 5315 BP 1125 EP 1128 DI 10.1126/science.276.5315.1125 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ225 UT WOS:A1997WZ22500048 PM 9173543 ER PT J AU Yang, LY Harrata, AK Lee, CS AF Yang, LY Harrata, AK Lee, CS TI On-line micellar electrokinetic chromatography electrospray ionization mass spectrometry using anodically migrating micelles SO ANALYTICAL CHEMISTRY LA English DT Article ID CAPILLARY ZONE ELECTROPHORESIS; PERFORMANCE LIQUID-CHROMATOGRAPHY; DEGRADATION PRODUCTS; ELECTROOSMOTIC FLOW; S-TRIAZINES; INTERFACE; SEPARATION; SURFACTANT; PEPTIDES AB On-line micellar electrokinetic chromatography (MEKC)-electrospray ionization mass spectrometry (ESIMS) is demonstrated for the analysis of chlorotriazine herbicides and barbiturates. In this study, the micellar velocity is directly manipulated by the adjustment of electroosmosis rather than the electrophoretic velocity of the micelle. The electroosmotic now is adjusted against the electrophoretic velocity of the micelle by changing the solution pH in MEKC. The elimination of MEKC surfactant introduction into ESIMS is achieved with an anodically migrating micelle, moving away from the electrospray interface. The effects of moving surfactant boundary in the MEKC capillary on separation efficiency and resolution of triazine herbicides and barbiturates are investigated. The mass detection of herbicides and barbiturates sequentially eluted from the MEKC capillary is acquired using the positive and negative electrospray modes, respectively. C1 IOWA STATE UNIV,USDOE,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,USDOE,AMES LAB,AMES,IA 50011. FU NIGMS NIH HHS [R01 GM 53231] NR 30 TC 64 Z9 65 U1 2 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 15 PY 1997 VL 69 IS 10 BP 1820 EP 1826 DI 10.1021/ac961202+ PG 7 WC Chemistry, Analytical SC Chemistry GA WX861 UT WOS:A1997WX86100004 PM 9164158 ER PT J AU Pallavicini, MG Redfearn, W Necas, E Brecher, G AF Pallavicini, MG Redfearn, W Necas, E Brecher, G TI Rescue from lethal irradiation correlates with transplantation of 10-20 CFU-S-day 12 SO BLOOD CELLS MOLECULES AND DISEASES LA English DT Article DE stem cells; CFU-S; progenitor cells; radioprotection; 5-fluorouracil; flow cytometry ID HEMATOPOIETIC STEM-CELLS; COLONY-FORMING CELLS; MURINE BONE-MARROW; RADIOPROTECTIVE ABILITY; SUBSETS; SPLEEN; TERM; ENRICHMENT; MICE; MEGAKARYOCYTE AB Repopulation by donor cells of a bone marrow ablated by irradiation is now recognized to proceed in two phases: initial repopulation that may be temporary followed by permanent engraftment of longterm repopulating cells (LTRC). While a single LTRC has been shown to be capable of restoring the entire lymph-hemopoietic system of an irradiated animal, the identity of the temporary repopulating cells has not been established unequivocally. We used the results of transplantation of subpopulations successively enriched for LTRC and containing varying numbers of CFU-S-12 (colony-forming units in the spleen at day 12 post transplantation) and progenitors to determine the likely cell type and number of cells needed for initial survival after radiation, Subpopulations from untreated and 5-fluorouracil-treated mice were discriminated on the basis of antibody reactivity, Hoechst 33342 and rhodamine 123 fluorescence intensity and light scattering properties. The minimum rescue inocula varied greatly in CFU-GEMM, BFU-E and CFU-GM content. One to two CFU-S-12 were uniformly present in all isolated suspensions that rescued 50% of lethally irradiated animals. In view of the known average seeding efficiency of CFU-S, our studies suggest that transfusion of 10-20 CFU-S day 12/13 is responsible for radioprotection. Evidence that multiple CFU-S day 12/13 are needed for initial repopulation is also supported by quantitative estimates of the number of mature cells that can be produced by CFU-S. Transfusion of a single CFU-S day 12/13 can be shown to be grossly inadequate to provide the number of peripheral blood cells needed to ameliorate the severe pancytopenia following lethal irradiation by day 12-14, Our data also indicate that 5-fluorouracil-treated marrow subpopulations appear inferior to untreated subpopulations in their ability to contribute to initial repopulation when transfused at low cell doses into lethally irradiated recipients. C1 LAWRENCE BERKELEY LAB,DIV LIFE SCI,SAN FRANCISCO,CA 94143. CHARLES UNIV,FAC MED 1,PRAGUE,CZECH REPUBLIC. RP Pallavicini, MG (reprint author), UNIV CALIF SAN FRANCISCO,CTR CANC,BOX 0808,SAN FRANCISCO,CA 94143, USA. NR 27 TC 4 Z9 4 U1 0 U2 1 PU BLOOD CELLS FOUNDATION PI LA JOLLA PA C/O ERNEST BEUTLER SCRIPPS RES INST, DEPT MOLECULAR EXP MEDICINE, LA JOLLA, CA 92037 SN 1079-9796 J9 BLOOD CELL MOL DIS JI Blood Cells Mol. Dis. PD MAY 15 PY 1997 VL 23 IS 9 BP 157 EP 168 DI 10.1006/bcmd.1997.0133 PG 12 WC Hematology SC Hematology GA WZ556 UT WOS:A1997WZ55600002 PM 9236154 ER PT J AU Sood, R Blake, T Aksentijevich, I Wood, G Chen, X Gardner, D Shelton, DA Mangelsdorf, M Orsborn, A Pras, E Balow, JE Centola, M Deng, ZM Zaks, N Chen, XG Richards, N FischelGhodsian, N Rotter, JI Pras, M Shohat, M Deaven, LL Gumucio, DL Callen, DF Richards, RI Collins, FS Liu, PP Kastner, DL Doggett, NA AF Sood, R Blake, T Aksentijevich, I Wood, G Chen, X Gardner, D Shelton, DA Mangelsdorf, M Orsborn, A Pras, E Balow, JE Centola, M Deng, ZM Zaks, N Chen, XG Richards, N FischelGhodsian, N Rotter, JI Pras, M Shohat, M Deaven, LL Gumucio, DL Callen, DF Richards, RI Collins, FS Liu, PP Kastner, DL Doggett, NA TI Construction of a 1-Mb restriction-mapped cosmid contig containing the candidate region for the familial mediterranean fever locus (MEFV) on chromosome 16p13.3 SO GENOMICS LA English DT Article ID HIGH GENE-FREQUENCY; PHYSICAL MAP; HUMAN GENOME; HUMAN DNA; SHORT ARM; LIBRARY; RESOLUTION; FRAGMENTS; SEQUENCES; ARMENIANS AB In this paper we describe the assembly and restriction map of a 1.05-Mb cosmid contig spanning the candidate region for familial Mediterranean fever (FMF), a recessively inherited disorder of inflammation localized to 16p13.3. Using a combination of cosmid walking and screening for P1, PAC, BAG, and YAC clones, we have generated a contig of genomic clones spanning similar to 1050 kb that contains the FMF critical region. The map consists of 179 cosmid, 15 P1, 10 PAC, 3 BAG, and 17 YAC clones, anchored by 27 STS markers. Eight additional STSs have been developed from the similar to 700 kb immediately centromeric to this genomic region. Five of the 35 STSs are microsatellites that have not been previously reported. NotI and EcoRI mapping of the overlapping cosmids, hybridization of restriction fragments from cosmids to one another, and STS analyses have been used to validate the assembly of the contig. Our contig totally subsumes the 250-kb interval recently reported, by founder haplotype analysis, to contain the FMF gene. Thus, our high-resolution clone map provides an ideal resource for transcriptional mapping toward the eventual identification of this disease gene. (C) 1997 Academic Press. C1 NIH,NATL CTR HUMAN GENOME RES,LAB GENE TRANSFER,BETHESDA,MD 20892. UNIV MICHIGAN,DEPT ANAT & CELL BIOL,ANN ARBOR,MI 48109. ADELAIDE WOMENS & CHILDRENS HOSP,DEPT CYTOGENET & MOL GENET,ADELAIDE,SA 5006,AUSTRALIA. CEDARS SINAI MED CTR,DEPT PEDIAT,LOS ANGELES,CA 90048. CEDARS SINAI MED CTR,DEPT MED GENET,LOS ANGELES,CA 90048. CHAIM SHEBA MED CTR,HELLER INST MED RES,IL-52621 TEL HASHOMER,ISRAEL. BEILINSON MED CTR,DEPT MED GENET,IL-49100 PETAH TIQWA,ISRAEL. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. RP Sood, R (reprint author), NIAMSD,ARTHRIT & RHEUMATISM BRANCH,NIH,BLDG 10,ROOM 9N-210,BETHESDA,MD 20892, USA. RI Liu, Paul/A-7976-2012; Callen, David/G-1975-2012; Mangelsdorf, Marie/A-2318-2013; OI Liu, Paul/0000-0002-6779-025X; Mangelsdorf, Marie/0000-0002-7855-7701; Callen, David/0000-0002-6189-9991 NR 39 TC 17 Z9 18 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD MAY 15 PY 1997 VL 42 IS 1 BP 83 EP 95 DI 10.1006/geno.1997.4629 PG 13 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WZ486 UT WOS:A1997WZ48600011 PM 9177779 ER PT J AU Giles, RH Petrij, F Dauwerse, HG denHollander, AI Lushnikova, T vanOmmen, GJB Goodman, RH Deaven, LL Doggett, NA Peters, DJM Breuning, MH AF Giles, RH Petrij, F Dauwerse, HG denHollander, AI Lushnikova, T vanOmmen, GJB Goodman, RH Deaven, LL Doggett, NA Peters, DJM Breuning, MH TI Construction of a 1.2-Mb contig surrounding, and molecular analysis of, the human CREB-binding protein (CBP/CREBBP) gene on chromosome 16p13.3 SO GENOMICS LA English DT Article ID RUBINSTEIN-TAYBI SYNDROME; DENOVO RECIPROCAL TRANSLOCATION; TRANSCRIPTIONAL COACTIVATOR CBP; SORTED HUMAN CHROMOSOME-16; POLYCYSTIC KIDNEY-DISEASE; POLYMERASE CHAIN-REACTION; PAIRED BOX GENE; INSITU HYBRIDIZATION; HUMAN DNA; MYELOID-LEUKEMIA AB In the interest of cloning and analyzing the genes responsible for two very different diseases, the Rubinstein-Taybi syndrome (RTS) and acute myeloid leukemia (AML) associated with the somatic translocation t(8;16)(pll;p13.3), we constructed a high-resolution restriction map of contiguous cosmids (contig) covering 1.2 Mb of chromosome 16p13.3. By fluorescence in situ hybridization and Southern blot analysis, we assigned all tested RTS and t(8;16) translocation breakpoints to a 100-kb region. We have previously reported exact physical locations of these 16p breakpoints, which all disrupt one gene we mapped to this interval: the CREB-binding protein (CBP or CREBBP) gene. Intriguingly, mutations in the CBP gene are responsible for RTS as well as the t(8;ls)-associated AML. CBP functions as an integrator in the assembly of various multiprotein regulatory complexes and is thus necessary for transcription in a broad range of transduction pathways. We report here the cloning, physical mapping, characterization, and full cDNA nucleotide sequence of the human CBP gene. (C) 1997 Academic Press. C1 LEIDEN UNIV,SYLVIUS LABS,DEPT HUMAN GENET,NL-2333 AL LEIDEN,NETHERLANDS. INT CHEM & BIOL PHYS,TALLINN,ESTONIA. OREGON HLTH SCI UNIV,VOLLUM INST,PORTLAND,OR 97201. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM. RI Breuning, Martijn/E-3429-2010; Hollander, Anneke/N-4911-2014 NR 87 TC 52 Z9 54 U1 0 U2 3 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0888-7543 J9 GENOMICS JI Genomics PD MAY 15 PY 1997 VL 42 IS 1 BP 96 EP 114 DI 10.1006/geno.1997.4699 PG 19 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WZ486 UT WOS:A1997WZ48600012 PM 9177780 ER PT J AU Craxton, M Olsen, A Goedert, M AF Craxton, M Olsen, A Goedert, M TI Human synaptotagmin V (SYT5): Sequence, genomic structure, and chromosomal location SO GENOMICS LA English DT Article ID NEUROTRANSMITTER RELEASE; TRANSMITTER RELEASE; NERVOUS-SYSTEM; MESSENGER-RNAS; RAT-BRAIN; BINDING; ISOFORM; MOUSE; P65; SYNAPSE AB We have determined the sequence, genomic structure, and chromosomal location of the human synaptotagmin V (SYTV) gene. The human SYTV gene encodes a 386-amino-acid product which is 91% identical to rat Syt V. The human SYTV open reading frame is interrupted by seven introns which can be alternatively spliced, Human SYTV was found to lie very close to SYTIII on chromosome 19q13.4 by PCR analysis of somatic cell hybrid DNA and by DNA hybridization to arrayed cosmids of the chromosome 19 metric physical map. This provides the first report of linked synaptotagmin genes. (C) 1997 Academic Press. C1 LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550. RP Craxton, M (reprint author), MRC,MOL BIOL LAB,HILLS RD,CAMBRIDGE CB2 2QH,ENGLAND. NR 30 TC 7 Z9 8 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 0888-7543 J9 GENOMICS JI Genomics PD MAY 15 PY 1997 VL 42 IS 1 BP 165 EP 169 DI 10.1006/geno.1997.4722 PG 5 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WZ486 UT WOS:A1997WZ48600021 PM 9177789 ER PT J AU Henderson, MG Reeves, GD Spence, HE Sheldon, RB Jorgensen, AM Blake, JB Fennell, JF AF Henderson, MG Reeves, GD Spence, HE Sheldon, RB Jorgensen, AM Blake, JB Fennell, JF TI First energetic neutral atom images from Polar SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID RING CURRENT AB Energetic neutral atoms are created when energetic magnetospheric ions undergo charge exchange with cold neutral atoms in the Earth's tenuous extended atmosphere (the geocorona). Since they are unaffected by the Earth's magnetic field, these energetic neutrals travel away in straight line trajectories from the points of charge exchange. The remote detection of these particles provides a powerful means through which the global distribution and properties of the geocorona and ring current can be inferred. Due to its 2 x 9 R-E polar orbit, the Polar spacecraft provides an excellent platform from which to observe ENAs because it spends much of its time in the polar caps which are usually free from the contaminating energetic charged particles that make observations of ENAs more difficult. In this brief report, we present the first ENA imaging results from Polar. Storm-time ENA images are presented for a northern polar cap apogee pass on August 29, 1996 and for a southern polar cap perigee pass on October 23, 1996. As well, we show with a third event (July 31, 1996) that ENA emissions can also be detected in association with individual substorms. C1 BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. AEROSP CORP,LOS ANGELES,CA 90009. RP Henderson, MG (reprint author), LOS ALAMOS NATL LAB,MAIL STOP D-436,LOS ALAMOS,NM 87545, USA. RI Spence, Harlan/A-1942-2011; Reeves, Geoffrey/E-8101-2011; Henderson, Michael/A-3948-2011; OI Reeves, Geoffrey/0000-0002-7985-8098; Henderson, Michael/0000-0003-4975-9029; Spence, Harlan/0000-0002-2526-2205 NR 9 TC 82 Z9 82 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 MAY 15 PY 1997 VL 24 IS 10 BP 1167 EP 1170 DI 10.1029/97GL01162 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WZ425 UT WOS:A1997WZ42500003 ER PT J AU Baty, RS Wolfe, WP AF Baty, RS Wolfe, WP TI Least-squares solutions of a general numerical method for arbitrary irregular grids SO INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING LA English DT Article DE coupled least squares; irregular grids AB This article describes a computational method to calculate solutions of elliptic boundary value problems using arbitrary irregular grids. The main feature of the numerical method is its ability to approximate solutions of differential equations without co-ordinate mapping or metric tensor information. For linear differential equations, the numerical method yields coupled linear systems on local computational cells. Optimal least-squares solutions of coupled linear systems are discussed and applied to the scheme. The numerical method is used to simulate potential flow for two model problems. The computational results are in very good agreement with analytical solutions. (C) 1997 by John Wiley & Sons, Ltd. RP Baty, RS (reprint author), SANDIA NATL LABS,ENGN SCI CTR,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 3 Z9 3 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0029-5981 J9 INT J NUMER METH ENG JI Int. J. Numer. Methods Eng. PD MAY 15 PY 1997 VL 40 IS 9 BP 1701 EP 1717 DI 10.1002/(SICI)1097-0207(19970515)40:9<1701::AID-NME135>3.0.CO;2-O PG 17 WC Engineering, Multidisciplinary; Mathematics, Interdisciplinary Applications SC Engineering; Mathematics GA WV962 UT WOS:A1997WV96200009 ER PT J AU Chason, E Picraux, ST Poate, JM Borland, JO Current, MI delaRubia, TD Eaglesham, DJ Holland, OW Law, ME Magee, CW Mayer, JW Melngailis, J Tasch, AF AF Chason, E Picraux, ST Poate, JM Borland, JO Current, MI delaRubia, TD Eaglesham, DJ Holland, OW Law, ME Magee, CW Mayer, JW Melngailis, J Tasch, AF TI Ion beams in silicon processing and characterization SO JOURNAL OF APPLIED PHYSICS LA English DT Review ID SINGLE-CRYSTAL SILICON; MOLECULAR-DYNAMICS SIMULATION; MONTE-CARLO SIMULATION; IMPLANTED SILICON; COMPUTER-SIMULATION; DEFECT PRODUCTION; PROJECTION LITHOGRAPHY; DISPLACEMENT CASCADES; INDUCED DEPOSITION; DOPANT DIFFUSION AB General trends in integrated circuit technology toward smaller device dimensions, lower thermal budgets, and simplified processing steps present severe physical and engineering challenges to ion implantation. These challenges, together with the need for physically based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in Si. In this article, we review the current status and future trends in ion implantation of Si at low and high energies with particular emphasis on areas where recent advances have been made and where further understanding is needed. Particularly interesting are the emerging approaches to defect and dopant distribution modeling, transient enhanced diffusion, high energy implantation and defect accumulation, and metal impurity gettering. Developments in the use of ion beams for analysis indicate much progress has been made in one-dimensional analysis, but that severe challenges for two-dimensional characterization remain. The breadth of ion beams in the semiconductor industry is illustrated by the successful use of focused beams for machining and repair, and the development of ion-based lithographic systems. This suite of ion beam processing, modeling, and analysis techniques will be explored both from the perspective of the emerging science issues and from the technological challenges. (C) 1997 American Institute of Physics. C1 NEW JERSEY INST TECHNOL, COLL SCI & LIBERAL ARTS, NEWARK, NJ 07102 USA. GENUS CORP, NEWBURYPORT, MA 01950 USA. APPL MAT INC, IMPLANT DIV, AUSTIN, TX 78759 USA. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. AT&T BELL LABS, LUCENT TECHNOL, MURRAY HILL, NJ 07974 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. UNIV FLORIDA, DEPT ELECT ENGN, GAINESVILLE, FL 32611 USA. EVANS E INC, PLAINSBORO, NJ 08536 USA. ARIZONA STATE UNIV, CTR SOLID STATE SCI, TEMPE, AZ 85287 USA. UNIV MARYLAND, COLLEGE PK, MD 20742 USA. UNIV TEXAS, AUSTIN, TX 78712 USA. RP SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 244 TC 179 Z9 180 U1 7 U2 42 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1997 VL 81 IS 10 BP 6513 EP 6561 DI 10.1063/1.365193 PG 49 WC Physics, Applied SC Physics GA WZ575 UT WOS:A1997WZ57500001 ER PT J AU Carlsten, BE AF Carlsten, BE TI Rippled beam free-electron laser amplifier using the axial free-electron laser interaction SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RELATIVISTIC KLYSTRON; ACCELERATION; PHYSICS AB A new microwave generation mechanism involving a scalloping annular electron beam is discussed. The beam interacts with the axial electric field of a TM0a mode in a smooth circular waveguide through the axial free-electron laser interaction, in which the beam ripple period is synchronous with the phase slippage of the rf mode relative to the electron beam. In this gaper, we analyze the ripple motion of the electron beam and derive the dispersion relation describing the exponential growth of the rf mode. We calculate the gain for a nominal design and as a function of beam current and ripple amplitude, and show that power gain on the order of 30 dB/m of interaction is achievable. We additionally demonstrate that, under the right conditions, the interaction is autoresonant. (C) 1997 American Institute of Physics. RP Carlsten, BE (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 20 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 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1997 VL 81 IS 10 BP 6570 EP 6578 DI 10.1063/1.365195 PG 9 WC Physics, Applied SC Physics GA WZ575 UT WOS:A1997WZ57500003 ER PT J AU Rao, MV Gardner, JA Chi, PH Holland, OW Kelner, G Kretchmer, J Ghezzo, M AF Rao, MV Gardner, JA Chi, PH Holland, OW Kelner, G Kretchmer, J Ghezzo, M TI Phosphorus and boron implantation in 6H-SiC SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID STOICHIOMETRIC DISTURBANCES; COMPOUND SEMICONDUCTORS; ION-IMPLANTATION; SILICON-CARBIDE; DIFFUSION; PROFILES; DISTRIBUTIONS AB Phosphorus and boron ion implantations were performed at various energies in the 50 keV-4 MeV range. Range statistics of P+ and B+ were established by analyzing the as-implanted secondary ion mass spectrometry depth profiles. Anneals were conducted in the temperature range of 1400-1700 degrees C using either a conventional resistive heating ceramic processing furnace or a microwave annealing station. The P implant was found to be stable at any annealing temperature investigated, but the B redistributed during the annealing process. The implant damage is effectively annealed as indicated by Rutherford backscattering measurements. For the 250 keV/1.2x10(15) cm(-2) P implant, annealed at 1600 degrees C for 15 min, the measured donor activation at room temperature is 34% with a sheet resistance of 4.8x10(2) Omega/square. The p-type conduction could not be measured for the B implants. (C) 1997 American Institute of Physics. C1 NIST,GAITHERSBURG,MD 20899. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. USN,RES LAB,WASHINGTON,DC 20375. GE CO,CORP RES & DEV,SCHENECTADY,NY 12301. RP Rao, MV (reprint author), GEORGE MASON UNIV,DEPT ELECT & COMP ENGN,FAIRFAX,VA 22030, USA. NR 38 TC 46 Z9 46 U1 1 U2 6 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 MAY 15 PY 1997 VL 81 IS 10 BP 6635 EP 6641 DI 10.1063/1.365236 PG 7 WC Physics, Applied SC Physics GA WZ575 UT WOS:A1997WZ57500011 ER PT J AU Fayeulle, S Nastasi, M AF Fayeulle, S Nastasi, M TI Stress in dc sputtered TiN/B-C-N multilayers SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID THIN-FILMS; INTERFACE STRESSES; SURFACE STRESS AB Stress in crystalline TiN/amorphous B-C-N multilayered thin films has been determined by the substrate curvature technique. It is established that the total stress is dependent on the number of deposited bilayers and on the bilayer repeat length. The linear relationship between the stress and the inverse of the bilayer repeat length allows calculation of the value of the interface stress. It is found to be compressive with a value between 1.79 and 2.46 J/m(2), depending on the calculation method. An apparent dependence between the interface stress and the total thickness of the multilayer film is observed. It is interpreted as an additional relaxation due to an increase of the roughness of the interfaces when the number of deposited bilayers is increased. (C) 1997 American Institute of Physics. C1 LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545. RP Fayeulle, S (reprint author), ECOLE CENT LYON,LAB MMP,CNRS,UMR 5621,F-69131 ECULLY,FRANCE. NR 22 TC 15 Z9 15 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1997 VL 81 IS 10 BP 6703 EP 6708 DI 10.1063/1.365211 PG 6 WC Physics, Applied SC Physics GA WZ575 UT WOS:A1997WZ57500022 ER PT J AU Ji, H Was, GS Jones, JW Moody, NR AF Ji, H Was, GS Jones, JW Moody, NR TI Effect of ion bombardment on in-plane texture, surface morphology, and microstructure of vapor deposited Nb thin films SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID BEAM-ASSISTED DEPOSITION; ORIENTATION; GROWTH AB Niobium films were deposited by physical vapor deposition (PVD) and ion-beam-assisted deposition (IBAD) using ion energies of 0, 250, 500 and 1000 eV, and R ratios (ion-to-atom arrival rate ratio) of 0, 0.1, and 0.4 on (100) silicon, amorphous glass, and (0001) sapphire substrates of thickness 50-1000 nm. Besides a {110} fiber texture, an in-plane texture was created by orienting the ion beam with respect to the substrate. The in-plane texture as measured by the degree of orientation was strongly dependent on both ion-beam energy and the R ratio. In fact, the degree of orientation in the films followed a linear relationship with the energy per deposited atom, E-n. The grain structure was columnar and the column width increased with normalized energy. The surface morphology depended on both the normalized energy of the ion beam and the film thickness. All films had domelike surface features that were oriented along the ion-beam incident direction. The dimension of these features increased with normalized energy and film thickness. Surface roughness also increased with normalized energy and film thickness, with the root-mean-square roughness increasing from 1.6 nm for the PVD sample (100 nm thick) to 36.7 nm for the IBAD film (1000 eV, R = 0.4, 800 nm thick). Both the surface morphology evolution and in-plane texture development in these films were the result of the different ion sputter rates among differently oriented grains. (C) 1997 American Institute of Physics. C1 UNIV MICHIGAN, DEPT NUCL ENGN & RADIOL SCI, ANN ARBOR, MI 48109 USA. UNIV MICHIGAN, DEPT MAT SCI & ENGN, ANN ARBOR, MI 48109 USA. SANDIA NATL LABS, LIVERMORE, CA 94551 USA. RP UNIV MICHIGAN, DEPT PHYS, ANN ARBOR, MI 48109 USA. NR 19 TC 20 Z9 21 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-8979 EI 1089-7550 J9 J APPL PHYS JI J. Appl. Phys. PD MAY 15 PY 1997 VL 81 IS 10 BP 6754 EP 6761 DI 10.1063/1.365217 PG 8 WC Physics, Applied SC Physics GA WZ575 UT WOS:A1997WZ57500029 ER PT J AU Hartman, RS Konitsky, WM Waldeck, DH Chang, YJ Castner, EW AF Hartman, RS Konitsky, WM Waldeck, DH Chang, YJ Castner, EW TI Probing solute-solvent electrostatic interactions: Rotational diffusion studies of 9,10-disubstituted anthracenes SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FLUORESCENCE ANISOTROPY DECAY; DIELECTRIC FRICTION MODELS; REORIENTATION DYNAMICS; CHEMICAL MOLECULES; BOUNDARY-CONDITION; COEFFICIENTS; HYDRODYNAMICS; SPECTROSCOPY; RELAXATION; ELLIPSOIDS AB The rotational diffusion of 9,10-disubstituted anthracenes is studied in various solvents. By systematic variation of the anthracene functionalities the influence of the electrostatic properties of the solute on the solute-solvent frictional coupling is investigated. These studies explore the range of validity of continuum based dielectric friction models for describing the frictional coupling. It is found that a continuum model of the solvent with an extended charge distribution for the solute is adequate in unassociated solvents, but does not adequately describe the friction in the associated solvent, benzyl alcohol. (C) 1997 American Institute of Physics. C1 UNIV PITTSBURGH,DEPT CHEM,PITTSBURGH,PA 15260. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. RP Hartman, RS (reprint author), LAROCHE COLL,DEPT CHEM,PITTSBURGH,PA 15237, USA. NR 49 TC 48 Z9 48 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 MAY 15 PY 1997 VL 106 IS 19 BP 7920 EP 7930 DI 10.1063/1.474119 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ032 UT WOS:A1997WZ03200004 ER PT J AU Dang, LX Chang, TM AF Dang, LX Chang, TM TI Molecular dynamics study of water clusters, liquid, and liquid-vapor interface of water with many-body potentials SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID POLARIZABLE WATER; FORCE-FIELDS; MODEL; SIMULATIONS; ASSOCIATION; DIFFRACTION; MECHANISM AB The molecular dynamics computer simulation technique is used to develop a rigid, four-site polarizable model for water. The suggested model reasonably describes the important properties of water clusters, the thermodynamic and structural properties of the liquid and the liquid/vapor interface of water. The minimum energy configurations and the binding energies for these clusters are in reasonable agreement with accurate electronic structure calculations. The model predicts that the water trimer, tetramer, and pentamer have cyclic planar minimum energy structures. A prismlike structure is predicted to be lowest in energy for the water hexamer, and a cagelike structure is the second lowest in energy, with an energy of about 0.2 kcal/mol higher than the prismlike structure. The results are consistent with recent quantum Monte Carlo simulations as well as electronic structure calculations. The computed thermodynamic properties for the model, at room temperature, including the liquid density, the enthalpy of vaporization, as well as the diffusion coefficient, are in excellent agreement with experimental values. Structural properties of liquid water, such as the radial distribution functions, neutron, and x-ray scattering intensities, were calculated and critically evaluated against the experimental measurements. In all cases, we found the agreement between the observed data and the computed properties to be quite reasonable. The computed density profile of the water's liquid/vapor interface shows that the interface is not sharp at a microscopic level and has a thickness of 3.2 Angstrom at 298 K. These results are consistent with those reported in earlier work on the same systems. The calculated surface tension at room temperature is in reasonable agreement with the corresponding experimental data. As expected, the computed average dipole moments of water molecules near the interface are close to their gas phase values, while water molecules far from the interface have dipole moments corresponding to their bulk values. (C) 1997 American Institute of Physics. RP Dang, LX (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. NR 55 TC 517 Z9 525 U1 12 U2 109 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 1997 VL 106 IS 19 BP 8149 EP 8159 DI 10.1063/1.473820 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ032 UT WOS:A1997WZ03200025 ER PT J AU Durbin, MK Malik, A Richter, AG Ghaskadvi, R Gog, T Dutta, P AF Durbin, MK Malik, A Richter, AG Ghaskadvi, R Gog, T Dutta, P TI Transitions to a new chiral phase in a Langmuir monolayer SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID X-RAY-DIFFRACTION; FATTY-ACID MONOLAYERS; LIQUID-CRYSTAL FILMS; SYMMETRY-BREAKING; SURFACE; WATER AB Isotherms and x-ray diffraction studies of eicosanoic acid Langmuir monolayers show a phase in which the molecular tilt is intermediate between nearest-neighbor (NN) and next-nearest-neighbor (NNN) directions. The transition from this ''I'' phase to an NN-tilted structure is first order, with a similar to 60 degrees change in the tilt direction, while the transition to an NNN-tilted structure is apparently continuous, These results can be explained using a Landau-type theory for uniaxially distorted lattices, which is a modification of an existing theory for hexagonal lattices [J.V. Selinger and D. R. Nelson, Phys. Rev. Lett. 61, 416 (1988)]. (C) 1997 American Institute of Physics. C1 OAK RIDGE NATL LAB, DIV MET & CERAM, OAK RIDGE, TN 37830 USA. RP Durbin, MK (reprint author), NORTHWESTERN UNIV, DEPT PHYS & ASTRON, EVANSTON, IL 60208 USA. NR 22 TC 33 Z9 33 U1 1 U2 8 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 1997 VL 106 IS 19 BP 8216 EP 8220 DI 10.1063/1.473825 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ032 UT WOS:A1997WZ03200030 ER PT J AU Melenkevitz, J Curro, JG AF Melenkevitz, J Curro, JG TI Optimized cluster theory of structurally symmetric polymer blends SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID INTEGRAL-EQUATION THEORY; INTERACTION SITE FLUIDS; CRITICAL-BEHAVIOR; LOCAL-STRUCTURE; MONTE-CARLO; INTRAMOLECULAR STRUCTURES; CHEMICAL-EQUILIBRIA; GINZBURG CRITERION; CLASSICAL FLUIDS; MOLECULAR-WEIGHT AB The thermodynamic properties of model structurally symmetric polymer blends were calculated using a recently developed theory that is a generalization of the optimized cluster theories for atomic mixtures and single component molecular systems. Within this approach, cluster expansions for the Helmholtz free energy and pair correlation functions were developed for a mixture of polymer chains modeled using the interaction site formalism. A series of topological reductions was then performed to render an approximate expression for these quantities; The theory was previously shown to be equivalent to a set of diagrammatically proper integral equations. The critical temperature was determined to scale linearly with chain length in agreement with neutron scattering measurements and computer simulations. The critical temperature was also found to be suppressed with respect to the mean-field value due to composition fluctuations. The effective interaction parameter, chi(s), at the critical composition was well represented by the functional form, chi(s)=A/T +B, where A and B are constants that depend on the chain length and total segment density. Deviations from random mixing were found to extend well beyond monomeric length scales and increased substantially as the critical temperature was approached. (C) 1997 American Institute of Physics. C1 LOUISIANA STATE UNIV,DEPT CHEM,BATON ROUGE,LA 70803. RP Melenkevitz, J (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 56 TC 3 Z9 3 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 MAY 15 PY 1997 VL 106 IS 19 BP 8221 EP 8231 DI 10.1063/1.473826 PG 11 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ032 UT WOS:A1997WZ03200031 ER PT J AU Chen, YJ Fenn, PT Stimson, S Ng, CY AF Chen, YJ Fenn, PT Stimson, S Ng, CY TI Bond selective dissociation of CH3SH+ and CH3CH2SH+ via collisional activation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID TOTAL CROSS-SECTIONS; MASS-SPECTROMETRY; CHARGE-TRANSFER; PHOTOIONIZATION; AUTOIONIZATION; PHASE; CH2S AB Strong preference is observed for the C-S bond scission process, leading to the formation of CH3++SH (CH3CH2++SH), in the collision induced dissociation (CID) reaction of CH3SH++Ar (CH3CH2SH++Ar). Since the dissociation-energy of 81.4 :kcal/mol (45.2 kcal/mol) for the CH3+-SH (CH3CH2+-SH) bond is significantly higher than that of 48 kcal/mol (33.9 kcal/mol) for the H-CH2SH+ [H-CH(CH3)SH+] bond, this observation indicates that the CID process is nonstatistical. The high yield for the C-S bond breakage process is attributed to the more efficient translational to vibrational energy transfer for the C-S stretching mode than for C-H and S-H stretching modes via collisional activation, and to weak couplings between the low frequency C-S and high frequency C-H and S-R stretching vibrational modes of CH3SH+ and CH3CH2SH+. (C) 1997 American Institute of Physics. C1 US DOE, AMES LAB, AMES, IA 50011 USA. IOWA STATE UNIV, DEPT CHEM, AMES, IA 50011 USA. RI Chen, Yu-Ju/E-9481-2015 NR 28 TC 9 Z9 9 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0021-9606 EI 1089-7690 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 15 PY 1997 VL 106 IS 19 BP 8274 EP 8277 DI 10.1063/1.473829 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ032 UT WOS:A1997WZ03200036 ER PT J AU Pak, Y Woods, RC Peterson, KA AF Pak, Y Woods, RC Peterson, KA TI Coupled cluster prediction of vibrational band intensities for SiF2 and PF2+ SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CORRELATED MOLECULAR CALCULATIONS; GAUSSIAN-BASIS SETS; WAVE-FUNCTIONS; ATOMS; SPECTRA; PROGRAMS C1 WASHINGTON STATE UNIV, DEPT CHEM, RICHLAND, WA 99352 USA. PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Pak, Y (reprint author), UNIV WISCONSIN, DEPT CHEM, 1101 UNIV AVE, MADISON, WI 53706 USA. NR 17 TC 1 Z9 1 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 MAY 15 PY 1997 VL 106 IS 19 BP 8283 EP 8284 DI 10.1063/1.473891 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ032 UT WOS:A1997WZ03200039 ER PT J AU Tanaka, K Ohta, K Fritz, JS AF Tanaka, K Ohta, K Fritz, JS TI Ion-exclusion chromatography of aliphatic carboxylic acids on a cation-exchange resin by elution with polyvinyl alcohol SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 9th International Ion Chromatography Symposium (IICS 96) CY SEP 16-20, 1996 CL UNIV READING, READING, ENGLAND HO UNIV READING DE mobile phase composition; carboxylic acids; polyvinyl alcohol ID CONDUCTIVITY DETECTION; SEPARATION; ELUENT AB Ion-exclusion chromatography of aliphatic carboxylic acids of different acidity (pK(a)) and hydrophobicity was investigated on a polystyrene-divinylbenzene (PS-DVB) based strongly acidic cation-exchange resin in the H+ form and conductivity detection by elution with polyvinyl alcohol (PVA). When water was used as an eluent, the resolution of the carboxylic acids was very low and the peak accompanied a fronting depending on their hydrophobicities. Therefore, to improve the peak shape and the peak resolution, aqueous eluents containing PVAs (degrees of polymerization, n=500, 1500 and 2000) with many OH groups were tested for the ion-exclusion chromatographic separation of the carboxylic acids. When aqueous eluents containing PVA were used, the fronting was decreased dramatically by the effect of increased hydrophilicity of the PS-DVB cation-exchange resin surface due to adsorption of OH group in PVA. The high resolution ion-exclusion chromatographic separation without the fronting and highly sensitive conductimetric detection of the carboxylic acids was accomplished successfully by elution with a 0.2% PVA (n=1500)-10% methanol-water. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. RP Tanaka, K (reprint author), NATL IND RES INST NAGOYA,KITA KU,HIRATE CHO 1-1,NAGOYA,AICHI 462,JAPAN. NR 10 TC 26 Z9 26 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 15 PY 1997 VL 770 IS 1-2 BP 211 EP 218 DI 10.1016/S0021-9673(96)01028-X PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XC911 UT WOS:A1997XC91100028 ER PT J AU Thornton, MJ Fritz, JS AF Thornton, MJ Fritz, JS TI Separation of inorganic anions in acidic solution by capillary electrophoresis SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article; Proceedings Paper CT 9th International Ion Chromatography Symposium (IICS 96) CY SEP 16-20, 1996 CL UNIV READING, READING, ENGLAND HO UNIV READING DE buffer composition; inorganic anions ID ZONE ELECTROPHORESIS; OPTIMIZATION AB Inorganic anions are almost always determined by capillary electrophoresis (CE) at an alkaline pH, so the analytes will be fully ionized. However, a long-chain quaternary ammonium salt usually must be added as a flow modifier to the carrier electrolyte to reverse the direction of the electroosmotic flow. By working at a sufficiently acidic pH, the electroosmotic flow in fused-silica capillaries is virtually eliminated, and anions can be separated simply by differences in their electrophoretic mobilities. Excellent separations were obtained for AuCl4- and the chloro complexes of platinum group elements in HCl solution at pH 2.0 to 2.4. No additional buffer or flow modifier was needed. This CE technique is an excellent way to follow slow hydrolytic reactions in which one or more of the chloride ligands is replaced by water. Sharp peaks and good separations were also obtained for MnO4-, VO3-, chromate, molybdate, ferrocyanide, ferricyanide and stable complex ions such as chromium oxalate (CrOx(3)(3-)). C1 IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. NR 11 TC 45 Z9 45 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD MAY 15 PY 1997 VL 770 IS 1-2 BP 301 EP 310 DI 10.1016/S0021-9673(97)00170-2 PG 10 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA XC911 UT WOS:A1997XC91100037 ER PT J AU Jayakody, S Chaudhuri, J Jankowski, AF AF Jayakody, S Chaudhuri, J Jankowski, AF TI X-ray characterization of annealed Cu/Ni multilayers SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID THIN-FILMS; DIFFRACTION; SUPERLATTICES; NICKEL AB A detailed study has been made of the X-ray characterization of Cu/Ni multilayers. Different mathematical models have been used to calculate the X-ray diffraction intensity and theoretical and experimental profiles were compared. An extended step model, which incorporates repeat-period fluctuations, and a model for interdiffusion were used. By varying the repeat-period fluctuation, the theoretical X-ray profile obtained from the extended step model was compared with the experimental curve. A best fit was obtained for a 1.6% fluctuation in the repeat period. For the second model, Cu/Ni samples annealed for different times (i.e. 2, 6, 14 and 20 h) were considered. The experimental values of the amplitudes of the first and second harmonics of the interplanar spacing were compared with the theoretical values. A coherent interface is predicted for the un-annealed sample. It is observed that the longer the an nea ling time, the higher is the interdiffusion. The interplanar spacing of the multi layers approaches the average interplanar spacing of the homogeneous Cu/Ni mixture with the longer annealing time (i.e. 20 h). C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Jayakody, S (reprint author), WICHITA STATE UNIV,DEPT MECH ENGN,WICHITA,KS 67208, USA. RI Chaudhuri, Jharna/E-8863-2013 NR 16 TC 1 Z9 1 U1 0 U2 2 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD MAY 15 PY 1997 VL 32 IS 10 BP 2605 EP 2609 DI 10.1023/A:1018606618689 PG 5 WC Materials Science, Multidisciplinary SC Materials Science GA XB297 UT WOS:A1997XB29700012 ER PT J AU Glarborg, P Kristensen, PG DamJohansen, K Miller, JA AF Glarborg, P Kristensen, PG DamJohansen, K Miller, JA TI Branching fraction of the NH2+NO reaction between 1210 and 1370 K SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID NITROUS-OXIDE FORMATION; THERMAL DENOX PROCESS; FLOW REACTOR; RATE-CONSTANT; + NO; KINETIC MEASUREMENTS; NITRIC-OXIDE; AMMONIA; TEMPERATURE; COMBUSTION AB The branching fraction for the NH2+NO reaction has been determined in the temperature range 1210-1370 K from flow reactor experiments on the NH3/NO/O2 and CO/NH3/NO/O-2 systems. The branching fraction is defined as alpha=k(1)/(k(1)+k(2)), where NH2+NO-->NNH+OH (1) and NH2+NO-->N-2+H2O (2). The experiments were performed at very low oxygen concentrations to minimize the impact of secondary reactions. The results show that a increases gradually from a value of 0.35+/-0.04 at 1211 K to 0.45+/-0.02 at 1369 K. The data blend smoothly with the most recent direct measurements and confirm the significant rise in branching fraction suggested by previous high-temperature determinations in static reactors and flames. C1 SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. RP Glarborg, P (reprint author), TECH UNIV DENMARK,DEPT CHEM ENGN,DK-2800 LYNGBY,DENMARK. NR 48 TC 26 Z9 26 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAY 15 PY 1997 VL 101 IS 20 BP 3741 EP 3745 DI 10.1021/jp970264g PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ292 UT WOS:A1997WZ29200015 ER PT J AU Grgur, BN Zhuang, G Markovic, NM Ross, PN AF Grgur, BN Zhuang, G Markovic, NM Ross, PN TI Electrooxidation of H-2/CO mixtures on a well-characterized Pt75Mo25 alloy surface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID ROTATING-DISK ELECTRODE; PT-RU ALLOYS; CO ELECTROOXIDATION; ACID AB The electrochemical oxidation of hydrogen in the presence of carbon monoxide (0.05-2%) on a well-characterized Pt75Mo25 alloy surface was examined using the rotating disk electrode technique in 0.5 M H2SO4 at 333 K. The surface composition of this alloy determined by low-energy ion scattering after sputter cleaning and annealing in UHV was essentially the same as the bulk. The shapes of the polarization curves are qualitatively similar to those for the Pt50Ru50 alloy examined previously: a high Tafel-slope (ca. 0.5 V/dec) region at low overpotential followed by a transition to a highly actively state where the current approaches the diffusion-limiting current; the potential where the transition to the active state occurs decreases with decreasing CO concentration, and the current in the low-overpotential region is roughly inverse half-order in the CO partial pressure. The magnitude of the current in the low-overpotential region on the Pt75Mo25 alloy is nearly the same as on the Pt50Ru50 alloy, but the potential for the transition to the active state is about 0.15 V higher. The magnitude of the current at 0.05-0.1 V with H-2 containing 100 ppm CO is sufficiently high that Pt-Mo alloy is of technical interest as an anode catalyst for low-temperature fuel cells fed with a reformed hydrocarbon fuel. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. OI Grgur, Branimir/0000-0003-4684-9053 NR 16 TC 124 Z9 130 U1 2 U2 16 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 MAY 15 PY 1997 VL 101 IS 20 BP 3910 EP 3913 DI 10.1021/jp9704168 PG 4 WC Chemistry, Physical SC Chemistry GA WZ290 UT WOS:A1997WZ29000003 ER PT J AU Pitzer, KS Roy, RN Wang, PM AF Pitzer, KS Roy, RN Wang, PM TI Thermodynamics of the system InCl3-HCl-H2O at 25 degrees C SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID AQUEOUS-SOLUTIONS; SULFURIC-ACID; ELECTROLYTES AB A comprehensive equation for the thermodynamic properties of the system InCl3-HCl-H2O at 25 degrees C in the ion-interaction (Pitzer) equation form is generated on the basis of a very recent and comprehensive array of electrochemical cell measurements of the HCl activity, together with older published measurements of the activity of InCl3 in mixtures with 0.02 m HCl. Alternate equations with and without explicit consideration of the ion pair InCl2+ as a separate species are tested. Excellent agreement is obtained on either formulation between calculated and measured activities, although considerable uncertainty remains concerning the standard potential for the In electrode. Suggestions are made for additional experiments to reduce this uncertainty. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. DRURY COLL,HOFFMAN DEPT CHEM,SPRINGFIELD,MO 65802. RP Pitzer, KS (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720, USA. NR 21 TC 16 Z9 16 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 MAY 15 PY 1997 VL 101 IS 20 BP 4120 EP 4126 DI 10.1021/jp964026h PG 7 WC Chemistry, Physical SC Chemistry GA WZ290 UT WOS:A1997WZ29000035 ER PT J AU Costanza, R dArge, R deGroot, R Farber, S Grasso, M Hannon, B Limburg, K Naeem, S ONeill, RV Paruelo, J Raskin, RG Sutton, P vandenBelt, M AF Costanza, R dArge, R deGroot, R Farber, S Grasso, M Hannon, B Limburg, K Naeem, S ONeill, RV Paruelo, J Raskin, RG Sutton, P vandenBelt, M TI The value of the world's ecosystem services and natural capital SO NATURE LA English DT Article ID ENVIRONMENTAL FUNCTIONS; VALUATION; MANAGEMENT; ECONOMICS; FISHERIES AB The services of ecological systems and the natural capital stocks that produce them are critical to the functioning of the Earth's life-support system. They contribute to human welfare, both directly and indirectly, and therefore represent part of the total economic value of the planet. We have estimated the current economic value of 17 ecosystem services for 16 biomes, based on published studies and a few original calculations. For the entire biosphere, the value (most of which is outside the market) is estimated to be in the range of US$16-54 trillion (10(12)) per year, with an average of US$33 trillion per year. Because of the nature of the uncertainties, this must be considered a minimum estimate. Global gross national product total is around US$18 trillion per year. C1 UNIV MARYLAND,INST ECOL ECON,SOLOMONS,MD 20688. UNIV WYOMING,DEPT ECON,LARAMIE,WY 82070. AGR UNIV WAGENINGEN,CTR ENVIRONM & CLIMATE STUDIES,NL-6700 HB WAGENINGEN,NETHERLANDS. UNIV PITTSBURGH,GRAD SCH PUBL & INT AFFAIRS,PITTSBURGH,PA 15260. UNIV ILLINOIS,DEPT GEOG,URBANA,IL 61801. UNIV ILLINOIS,NCSA,URBANA,IL 61801. INST ECOSYST STUDIES,MILLBROOK,NY 12545. UNIV MINNESOTA,DEPT ECOL EVOLUT & BEHAV,ST PAUL,MN 55108. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. UNIV BUENOS AIRES,FAC AGRON,DEPT ECOL,RA-1417 BUENOS AIRES,DF,ARGENTINA. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV CALIF SANTA BARBARA,NATL CTR GEOG INFORMAT & ANAL,DEPT GEOG,SANTA BARBARA,CA 93106. ECOL ECON RES & APPLICAT INC,SOLOMONS,MD 20688. RP Costanza, R (reprint author), UNIV MARYLAND,CTR ENVIRONM & ESTUARINE STUDIES,DEPT ZOOL,BOX 38,SOLOMONS,MD 20688, USA. RI Costanza, Robert/A-4912-2008; Sutton, Paul/A-6764-2013; Limburg, Karin/M-8380-2013 OI Costanza, Robert/0000-0001-6348-8734; Sutton, Paul/0000-0001-6972-3256; NR 33 TC 5197 Z9 7038 U1 428 U2 3496 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAY 15 PY 1997 VL 387 IS 6630 BP 253 EP 260 DI 10.1038/387253a0 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ167 UT WOS:A1997WZ16700043 ER PT J AU Falkowski, PG AF Falkowski, PG TI Evolution of the nitrogen cycle and its influence on the biological sequestration of CO2 in the ocean SO NATURE LA English DT Article ID EQUATORIAL PACIFIC-OCEAN; ATMOSPHERIC CO2; INTERGLACIAL CHANGES; MARINE ECOSYSTEMS; FRESH-WATER; CARBON; IRON; SEA; PRODUCTIVITY; CLIMATE AB Over geological time, photosynthetic carbon fixation in the oceans has exceeded respiratory oxidation of organic carbon. The imbalance between the two processes has resulted in the simultaneous accumulation of oxygen in, and drawdown of carbon dioxide from, the Earth's atmosphere, and the burial of organic carbon in marine sediments(1-3). It is generally assumed that these processes are limited by the availability of phosphorus(4,5), which is supplied by continental weathering and fluvial discharge(5-7). Over the past two million years,decreases in atmospheric carbon dioxide concentrations during glacial periods correlate with increases in the export of organic carbon from surface waters to the marine sediments(8-11), but variations in phosphorus fluxes appear to have been too small to account for these changes(12,13). Consequently, it has been assumed that total oceanic primary productivity remained relatively constant during glacial-to-interglacial transitions, although the fraction of this productivity exported to the sediments somehow increased during glacial periods(12,14). Here I present an analysis of the evolution of biogeochemical cycles which suggests that fixed nitrogen, not phosphorus, limits primary productivity on geological timescales. Small variations in the ratio of nitrogen fixation to denitrification can significantly change atmospheric carbon dioxide concentrations on glacial-to-interglacial timescales. The ratio of these two processes appears to be determined by the oxidation state of the ocean and the supply of trace elements, especially iron. RP Falkowski, PG (reprint author), BROOKHAVEN NATL LAB, DIV OCEANOG & ATMOSPHER SCI, UPTON, NY 11973 USA. NR 69 TC 615 Z9 648 U1 23 U2 212 PU NATURE PUBLISHING GROUP PI LONDON PA MACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLAND SN 0028-0836 J9 NATURE JI Nature PD MAY 15 PY 1997 VL 387 IS 6630 BP 272 EP 275 DI 10.1038/387272a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ167 UT WOS:A1997WZ16700049 ER PT J AU Kang, HS Tinoco, I AF Kang, HS Tinoco, I TI A mutant RNA pseudoknot that promotes ribosomal frameshifting in mouse mammary tumor virus SO NUCLEIC ACIDS RESEARCH LA English DT Article ID SPECTROSCOPY; PROTEINS; NMR AB A single A-->G mutation that changes a potential A.U base pair to a G.U pair at the junction of the stems and loops of a non-frameshifting pseudoknot dramatically increases its frameshifting efficiency in mouse mammary tumor virus, The structure of the non-frame-shifting pseudoknot APK has been found to be very different from that of pseudoknots that cause efficient frameshifting [Kang,H., Hines,J.V. and Tinoco,I. (1995) J. Mol. Biol., 259, 135-147], The 3-dimensional structure of the mutant pseudoknot was determined by restrained molecular dynamics based on NMR-derived interproton distance and torsion angle constraints, One striking feature of the mutant pseudoknot compared with the parent pseudoknot is that a G.U base pair forms at the top of stem 2, thus leaving only 1 nt at the junction of the two stems, The conformation is very different from that of the previously determined non-frameshifting parent pseudoknot, which lacks the A.U base pair at the top of the stem and has 2 nt between the stems, However, the conformation is quite similar to that of efficient frameshifting pseudoknots whose structures were previously determined by NMR, A single adenylate residue intervenes between the two stems and interrupts their coaxial stacking, This unpaired nucleotide produces a bent structure, The structural similarity among the efficient frameshifting pseudoknots indicates that a specific conformation is required for ribosomal frameshifting, further implying a specific interaction of the pseudoknot with the ribosome. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 10840] NR 22 TC 44 Z9 46 U1 0 U2 5 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 MAY 15 PY 1997 VL 25 IS 10 BP 1943 EP 1949 DI 10.1093/nar/25.10.1943 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WZ939 UT WOS:A1997WZ93900010 PM 9115361 ER PT J AU Taylor, AJ Rodriguez, G Some, D AF Taylor, AJ Rodriguez, G Some, D TI Ultrafast field dynamics in large-aperture photoconductors SO OPTICS LETTERS LA English DT Article ID TERAHERTZ RADIATION AB We investigated field screening mechanisms in large-aperture GaAs photoconductors, using an ultrafast pump-probe terahertz technique. After photoexcitation the bias field decreases to an intensity-dependent value as a result of near-field screening of the bias field. For longer delays the field exhibits an intensity-dependent decrease that results from a space-charge field caused by transport-induced charge separation. These measurements support recent theoretical results that the dominant saturation mechanism that limits terahertz output from large-aperture photoconductors is near-field screening of the bias field because the space-charge field develops on a much longer time scale than that of the terahertz pulse. (C) 1997 Optical Society of America. RP Taylor, AJ (reprint author), LOS ALAMOS NATL LAB,MS D429,LOS ALAMOS,NM 87545, USA. RI Rodriguez, George/G-7571-2012 OI Rodriguez, George/0000-0002-6044-9462 NR 9 TC 11 Z9 11 U1 0 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 MAY 15 PY 1997 VL 22 IS 10 BP 715 EP 717 DI 10.1364/OL.22.000715 PG 3 WC Optics SC Optics GA XA242 UT WOS:A1997XA24200018 PM 18185638 ER PT J AU Richman, BA Krumbugel, MA Trebino, R AF Richman, BA Krumbugel, MA Trebino, R TI Temporal characterization of mid-IR free-electron-laser pulses by frequency-resolved optical gating SO OPTICS LETTERS LA English DT Article ID ULTRASHORT PULSES; AMPLIFIER; PHASE; RETRIEVAL AB We performed what we believe are the first practical full-temporal-characterization measurements of ultrashort pulses from a free-electron laser (FEL). Second-harmonic-generation frequency-resolved optical gating (FROG) was used to measure a train of mid-IR pulses distorted by a saturated water-vapor absorption line and showing free-induction decay. The measured direction of time was unambiguous because of prior knowledge regarding free-induction decay. These measurements require only 10% of the power of the laser beam and demonstrate that FROG can be implemented as a pulse diagnostic simultaneously with other experiments on a FEL. (C) 1997 Optical Society of America. RP Richman, BA (reprint author), SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551, USA. NR 14 TC 25 Z9 25 U1 0 U2 8 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0146-9592 J9 OPT LETT JI Opt. Lett. PD MAY 15 PY 1997 VL 22 IS 10 BP 721 EP 723 DI 10.1364/OL.22.000721 PG 3 WC Optics SC Optics GA XA242 UT WOS:A1997XA24200020 PM 18185640 ER PT J AU Hess, S Kroger, M Hoover, WG AF Hess, S Kroger, M Hoover, WG TI Shear modulus of fluids and solids SO PHYSICA A LA English DT Article ID NONEQUILIBRIUM MOLECULAR-DYNAMICS; SPHERICAL-PARTICLES; PHASE-TRANSITION; ORDER AB The shear modulus tensor, whose components are Voigt elastic moduli, is expressed as an N-particle average. The Born-Green and the fluctuation contributions are identified and, when possible, also expressed in terms of integrals over the pair-correlation function. Symmetry considerations are invoked for systems of spherical particles in both isotropic and cubic states. Results from molecular dynamics simulations are presented for particles with a purely repulsive Lennard-Jones interaction. Shear and bulk moduli are displayed graphically as functions of the density for fluid and cubic crystalline states. The shear modulus proves to be a good indicator for the fluid-solid phase transition. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. UNIV CALIF DAVIS,LIVERMORE,CA 94551. RP Hess, S (reprint author), TECH UNIV BERLIN,INST THEORET PHYS,PN 7-1,HARDENBERGSTR 36,D-10623 BERLIN,GERMANY. OI Kroger, Martin/0000-0003-1402-6714 NR 32 TC 29 Z9 29 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0378-4371 J9 PHYSICA A JI Physica A PD MAY 15 PY 1997 VL 239 IS 4 BP 449 EP 466 DI 10.1016/S0378-4371(97)00045-9 PG 18 WC Physics, Multidisciplinary SC Physics GA XD305 UT WOS:A1997XD30500001 ER PT J AU Chmaissem, O Jorgensen, JD Hinks, DG Storey, BG Dabrowski, B Zhang, H Marks, LD AF Chmaissem, O Jorgensen, JD Hinks, DG Storey, BG Dabrowski, B Zhang, H Marks, LD TI Structure and superconductivity in Cr-substituted HgBa2CuO4+delta SO PHYSICA C LA English DT Article DE mercury-based superconductors; chromium substitution; superconductivity; neutron diffraction; structural analysis ID NEUTRON POWDER DIFFRACTION; CRYSTAL-STRUCTURE; ROOM-TEMPERATURE; HGBA2CA2CU3O8+DELTA; HGBA2CACU2O6+DELTA; 10-K; (HG AB Chromium-substituted Hg1-xCrxBa2CuO4+delta compounds have been synthesized. Cr can be incorporated into the structure with a solubility limit around x approximate to 0.27. Cr substitutes at the Hg site and is tetrahedrally coordinated to four oxygen atoms, Two of these are apical oxygen atoms that have moved to new positions (O2') and two are in the Hg/Cr plane (O3) at a (xx 0) site, Additional oxygen atoms (O4) in the Hg/Cr plane at(1/2 1/2 0) affect the carrier concentration, as for HgBa2CuO4+delta. in the as-synthesized samples, T-c decreases with increasing Cr content. Attempts to adjust the carrier concentration by post annealing in oxygen at low temperature destroy superconductivity because the samples are metastable under ambient conditions. (C) 1997 Elsevier Science B.V. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. NORTHWESTERN UNIV,DEPT MAT SCI & ENGN,EVANSTON,IL 60208. NORTHWESTERN UNIV,SCI & TECHNOL CTR SUPERCOND,EVANSTON,IL 60208. NO ILLINOIS UNIV,DEPT PHYS,DE KALB,IL 60115. RP Chmaissem, O (reprint author), ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439, USA. RI Marks, Laurence/B-7527-2009 NR 21 TC 15 Z9 15 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD MAY 15 PY 1997 VL 279 IS 1-2 BP 1 EP 10 DI 10.1016/S0921-4534(97)00134-2 PG 10 WC Physics, Applied SC Physics GA XG695 UT WOS:A1997XG69500001 ER PT J AU Wang, LS Wu, HB Cheng, HS AF Wang, LS Wu, HB Cheng, HS TI Photoelectron spectroscopy of small chromium clusters: Observation of even-odd alternations and theoretical interpretation SO PHYSICAL REVIEW B LA English DT Article ID SMALL IRON CLUSTERS; TRANSITION-METAL CLUSTERS; ELECTRONIC-STRUCTURE; CR CLUSTERS; MAGNETISM; SPECTRA; GEOMETRY; STATES; SIZE AB We report an extensive photoelectron-spectroscopy study of size-selected Cr-n(-) (n = 2-70) clusters. Even-odd alternations are observed for the small Cr-n clusters and their electron affinities. The spectra of clusters with an even number of atoms show less density of states near the threshold, while those with odd clusters show more complex features. A dimer growth path found in a previous theoretical study is used to interpret the data and accounts well for the even-odd effects. The work provides a key contribution to the understanding of the complicated electronic structure of the Cr clusters. C1 PACIFIC NW LAB, EMSL, RICHLAND, WA 99352 USA. AIR PROD & CHEM INC, ALLENTOWN, PA 18195 USA. RP Wang, LS (reprint author), WASHINGTON STATE UNIV, DEPT PHYS, RICHLAND, WA 99352 USA. NR 34 TC 47 Z9 49 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 12884 EP 12887 DI 10.1103/PhysRevB.55.12884 PG 4 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400019 ER PT J AU Cote, M Zakharov, O Rubio, A Cohen, ML AF Cote, M Zakharov, O Rubio, A Cohen, ML TI Ab initio calculations of the pressure-induced structural phase transitions for four II-VI compounds SO PHYSICAL REVIEW B LA English DT Article ID PLANE-WAVE CALCULATIONS; ELECTRONIC-PROPERTIES; GROUND-STATE; CDTE; SEMICONDUCTORS; ZNSE; CDSE; PSEUDOPOTENTIALS; TRANSFORMATION; WURTZITE AB We report on pseudopotential calculations of the structural properties and pressure-induced solid-solid phase transitions for four II-VI compounds: ZnSe, ZnTe, CdSe, and CdTe. For each of these compounds, we fix the zinc-blende structure as the ambient pressure phase and consider the rocksalt, cinnabar, and Cmcm structures as candidates for the high-pressure phases. We calculate the transition pressures and the changes in specific volume for each compound. The pressure dependences of the structural parameters of the cinnabar and the Cmcm phases are determined. The Cmcm structure appears to be a common high-pressure phase for the II-VI and III-V semiconductors. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV VALLADOLID,DEPT FIS TEOR,E-47011 VALLADOLID,SPAIN. RP Cote, M (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Cote, Michel/H-3942-2012; Rubio, Angel/A-5507-2008 OI Cote, Michel/0000-0001-9046-9491; Rubio, Angel/0000-0003-2060-3151 NR 50 TC 119 Z9 119 U1 0 U2 12 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 13025 EP 13031 DI 10.1103/PhysRevB.55.13025 PG 7 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400041 ER PT J AU Zhang, Y Mascarenhas, A AF Zhang, Y Mascarenhas, A TI Orientational superlattices formed by CuPt-ordered zinc-blende semiconductor alloys SO PHYSICAL REVIEW B LA English DT Article ID QUANTUM-WELLS; BAND-GAP; MOTION; STRAIN; GAINP2 AB We performed a systematic study on a nonconventional semiconductor heterostructure-orientational superlattices (OSL's)-based on CuPt-ordered zinc-blende alloys. Instead of the band offset in conventional superlattices, it is the discontinuity in the angular momentum which brings about the superlattice effects in orientational superlattices. Valence-band structures of five polytypes of OSL's formed by CuPt-ordered GaInP2 layers have been classified according to their symmetries and calculated numerically by using the envelope-function approximation for structures with different periods, ratios of layer thickness. and degree of order. On one hand, features similar to those in conventional superlattices-wave-function modulation, bandgap modification. and the formation of subbands and minigaps-can be achieved purely from an orientational alternation of the semiconductor layers. On the other hand, the dependence of energy levels on layer thickness and the wave-function distributions in OSL's are distinct from that in conventional superlattices. RP Zhang, Y (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 29 TC 14 Z9 14 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 13100 EP 13110 DI 10.1103/PhysRevB.55.13100 PG 11 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400052 ER PT J AU Klimov, VI McBranch, DW AF Klimov, VI McBranch, DW TI Auger-process-induced charge separation in semiconductor nanocrystals SO PHYSICAL REVIEW B LA English DT Article ID FEMTOSECOND NONLINEAR TRANSMISSION; CDSE QUANTUM DOTS; OPTICAL NONLINEARITIES; CARRIER-RECOMBINATION; DOPED GLASSES; ABSORPTION; LIGHT; MICROCRYSTALS AB Femtosecond nonlinear transmission techniques are applied to study mechanisms for optical nonlinearities and ultrafast carrier dynamics in CdS nanocrystals (NC's). The obtained data indicate the change in a dominant hole relaxation channel at high pump levels where nonlinear recombination effects start to play a significant role. This is manifested as a distinct difference in nonlinear-optical responses measured at low and high pump intensities in quasiequilibrium at long times after excitation. The analysis of the wavelength and time dependence of the nonlinear transmission over a wide pump-intensity range shows clearly that this difference is due to an Auger-process-assisted trapping of holes at surface/interface-related states. This trapping leads to efficient charge separation and the generation of a dc electric field that modifies the nonlinear optical response in NC's at high pump intensities. RP Klimov, VI (reprint author), LOS ALAMOS NATL LAB,DIV CHEM SCI & TECHNOL,CST-6,MS-1585,LOS ALAMOS,NM 87545, USA. NR 34 TC 85 Z9 86 U1 2 U2 22 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 13173 EP 13179 DI 10.1103/PhysRevB.55.13173 PG 7 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400060 ER PT J AU Knutsen, K Orlando, TM AF Knutsen, K Orlando, TM TI Photon-stimulated desorption of O(P-3) and NO((2)Pi) from NaNO3 single crystals SO PHYSICAL REVIEW B LA English DT Article ID DISSOCIATIVE ELECTRON-ATTACHMENT; ALKALI-HALIDE CRYSTALS; NACL 100 SURFACES; VELOCITY DISTRIBUTIONS; OXYGEN MOLECULES; LATTICE-DEFECTS; SODIUM-NITRATE; ATOMIC OXYGEN; EMISSION; EXCITATION AB The 193-nm photon-stimulated desorption (PSD) of O(P-3) and NO((II)-I-2) from NaNO3 crystals was detected via state-resolved laser ionization spectroscopy. Yields of these dissociation fragments show a one-photon dependence upon the 193-nm laser fluence, with no observable thresholds, down to similar to 1 mu J/cm(2). The O(P-3) J-state distribution is nonthermal, and the O(P-3) and NO((II)-I-2) velocity distributions are bimodal, with thermal and nonthermal components, consistent with near-surface dissociation events. We discuss the results in terms of exciton creation and fragment production via dissociative anionic pathways. We also discuss the similarities between our experimental results and those of alkali halide PSD studies, and suggest that the exciton-mediated PSD mechanism developed for alkali halides may be extended to apply generally to insulators with polyatomic anions. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 42 TC 20 Z9 20 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 13246 EP 13252 DI 10.1103/PhysRevB.55.13246 PG 7 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400068 ER PT J AU Beck, KM Taylor, DP Hess, WP AF Beck, KM Taylor, DP Hess, WP TI Photostimulated desorption of CO from geologic calcite following 193-nm irradiation SO PHYSICAL REVIEW B LA English DT Article ID ELECTRON-STIMULATED DESORPTION; LASER-INDUCED-FLUORESCENCE; GAS-SURFACE INTERACTIONS; EXCITED-ATOM PRODUCTION; NACL 100 SURFACES; ALKALI-HALIDES; 111 SURFACE; EXCITATION; EMISSION; SCATTERING AB We report the results of a photostimulated desorption study of neutral CO product from geologic calcite using very low fluence 193-nm excimer laser radiation. Detailed product state distributions are obtained using (2+1) resonance enhanced multiphoton ionization. The CO translational energy can be characterized by a temperature (T= 110+/-15 K) significantly lower than that of the substrate (T= 295 K). The CO rotational state distribution is non-Boltzmann and there is step structure every four or five rotational states. The evolution of CO emission as a function of laser exposure shows no incubation period or enhanced CO photodesorption over time. The CO yield is linear with laser power and displays no detectable threshold. The low kinetic energy of the desorbed CO and the nonthermal CO distributions implicate the decay of a surface species or state. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. NR 71 TC 14 Z9 14 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 13253 EP 13262 DI 10.1103/PhysRevB.55.13253 PG 10 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400069 ER PT J AU Wampler, WR Myers, SM Follstaedt, DM AF Wampler, WR Myers, SM Follstaedt, DM TI Surface silicon-deuterium bond energy from gas-phase equilibration - Reply SO PHYSICAL REVIEW B LA English DT Editorial Material ID HYDROGEN AB The free energy of binding of deuterium to a surface silicon atom is obtained directly from our previously reported experiment. However, comparison with first-principles calculations of the surface Si-D bond energy requires an estimation of the contribution to the free energy from the vibrational entropy S-vib. Herring and Van de Walle determine a value of 2.99 eV for the bond energy at 800 degrees C from our data, using a harmonic oscillator model to estimate S-vib Our method of estimating S-vib from Solubility measurements gives a lower Si-D bond energy of 2.49 eV. These values are both lower than the bond energy from Van de Walle's first-principles calculation. Uncertainties involved in comparing theory with experiment are discussed. RP Wampler, WR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 TC 2 Z9 2 U1 1 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 19 BP 13319 EP 13320 DI 10.1103/PhysRevB.55.13319 PG 2 WC Physics, Condensed Matter SC Physics GA XC404 UT WOS:A1997XC40400079 ER PT J AU Gweon, GH Allen, JW Clack, JA Zhang, YX Poirier, DM Benning, PJ Olson, CG Marcus, J Schlenker, C AF Gweon, GH Allen, JW Clack, JA Zhang, YX Poirier, DM Benning, PJ Olson, CG Marcus, J Schlenker, C TI Direct Fermi-surface image of hidden nesting for NaMo6O17 and KMo6O17 SO PHYSICAL REVIEW B LA English DT Article ID DENSITY-WAVE INSTABILITY; PURPLE BRONZE K0.9MO6O17; MOLYBDENUM BRONZES; POTASSIUM; CONDUCTOR AB We report direct Fermi-surface images obtained with angle-resolved photoemission spectroscopy (ARPES) for NaMo6O17 and KMo6O17 above the charge-density wave transition temperatures. We also report ARPES spectra of the valence band of NaMo6O17. The images imply a Fermi surface (FS) based on three underlying quasi-one-dimensional (quasi-1D) surfaces. Thus it agrees in detail with that expected in the hidden nesting picture of Whangbo et al. [Science 252, 96 (1991)], but differs greatly from a FS deduced in a previous study by Breuer et al. [Phys. Rev. Lett. 76, 3172 (1996)], which found only two underlying quasi-1D surfaces. C1 IOWA STATE UNIV,AMES LAB,AMES,IA 50011. ETUD PROPRIETES ELECT SOLIDES LAB,CNRS,F-38042 GRENOBLE,FRANCE. RP Gweon, GH (reprint author), UNIV MICHIGAN,RANDALL LAB PHYS,ANN ARBOR,MI 48109, USA. NR 14 TC 34 Z9 34 U1 2 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 MAY 15 PY 1997 VL 55 IS 20 BP 13353 EP 13356 PG 4 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000001 ER PT J AU Harff, NE Simmons, JA Lyo, SK Klem, JF Boebinger, GS Pfeiffer, LN West, KW AF Harff, NE Simmons, JA Lyo, SK Klem, JF Boebinger, GS Pfeiffer, LN West, KW TI Magnetic breakdown and Landau-level spectra of a tunable double-quantum-well Fermi surface SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL ELECTRON-SYSTEMS; FIELD; GASES; MASS; LAYER AB By measuring longitudinal resistance, we. map the Landau-level spectra of double quantum wells as a function of both parallel (B-parallel to) and perpendicular (B-perpendicular to) magnetic fields. In this continuously tunable highly nonparabolic system, both the cyclotron mass and Fermi energy of the two Fermi surface orbits change in opposite directions with B-parallel to. The two corresponding ladders of Landau levels formed at finite B-perpendicular to thus exhibit multiple crossings. A third set of Landau levels, independent of B-parallel to, arises from magnetic breakdown of the Fermi surface. Semiclassical calculations show good agreement with the data. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. OREGON STATE UNIV,CORVALLIS,OR 97331. RP Harff, NE (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 25 TC 34 Z9 34 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 MAY 15 PY 1997 VL 55 IS 20 BP 13405 EP 13408 PG 4 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000014 ER PT J AU Zeman, J Martinez, G Yu, PY Uchida, K AF Zeman, J Martinez, G Yu, PY Uchida, K TI Band alignment and photoluminescence up-conversion at the GaAs/(ordered)GaInP2 heterojunction SO PHYSICAL REVIEW B LA English DT Article ID VAPOR-PHASE EPITAXY; PRESSURE; LUMINESCENCE; TEMPERATURE AB The up-conversion of photoluminescence in a series of GaAs/(ordered)GaInP2 heterojunctions has been investigated using high magneticfield and high pressure. Samples which exhibit this effect have been demonstrated to have a type-II band alignment and also localization centers in GaInP2, Some samples revealing a type-I band alignment do not show this effect at atmospheric pressure. However, such a sample exhibits up-conversion under a hydrostatic pressure of 1.2 GPa. Our results establish a type-II band alignment as one of the key elements for explaining the observed up-conversion. C1 UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. NIPPON SANSO TSUKUBA LAB,TSUKUBA,IBARAKI,JAPAN. RP Zeman, J (reprint author), MAX PLANCK INST FESTKORPERFORSCH,CNRS,GRENOBLE HIGH MAGNET FIELD LAB,25 AVE MARTYRS,F-38042 GRENOBLE 9,FRANCE. NR 15 TC 38 Z9 38 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 MAY 15 PY 1997 VL 55 IS 20 BP 13428 EP 13431 PG 4 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000020 ER PT J AU Kim, YJ Westphal, C Ynzunza, RX Galloway, HC Salmeron, M VanHove, MA Fadley, CS AF Kim, YJ Westphal, C Ynzunza, RX Galloway, HC Salmeron, M VanHove, MA Fadley, CS TI Interlayer interactions in epitaxial oxide growth: FeO on Pt(111) SO PHYSICAL REVIEW B LA English DT Article AB We have studied the first monolayer of epitaxial iron oxide on Pt(111) with x-ray photoelectron diffraction and other methods. We confirm a previously proposed superlattice model for this monolayer, but also conclude that the oxide grows as a bilayer of FeO(111) with the oxygen layer outermost, the Fe-O interlayer distance is highly compressed relative to bulk FeO by about 50%, and only one of two possible domains forms due to interlayer interactions between oxygen and platinum. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF DAVIS,DEPT PHYS,DAVIS,CA 95616. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. RP Kim, YJ (reprint author), UNIV HAWAII MANOA,DEPT CHEM,HONOLULU,HI 96822, USA. RI Van Hove, Michel/A-9862-2008 OI Van Hove, Michel/0000-0002-8898-6921 NR 10 TC 89 Z9 90 U1 2 U2 16 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 MAY 15 PY 1997 VL 55 IS 20 BP 13448 EP 13451 DI 10.1103/PhysRevB.55.R13448 PG 4 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000025 ER PT J AU Wei, SH Zunger, A AF Wei, SH Zunger, A TI Electronic and structural anomalies in lead chalcogenides SO PHYSICAL REVIEW B LA English DT Article ID ABSORPTION FINE-STRUCTURE; ATOMIC-SCALE STRUCTURE; RANDOM SOLID-SOLUTIONS; EFFECTIVE MASSES; ALLOYS; GA1-XINXAS; PBTE; SNTE AB The rocksalt-structure PbS, PbSe, and PbTe semiconductors and their alloys exhibit a series of electronic structure anomalies relative to the II-VI system, including the occurrence of direct gaps at the L point, anomalous order of band gaps and valence-band maximum energies versus anions, negative optical bowing, and negative band-gap pressure coefficients. We show that these anomalies result from the occurrence of the Pb s band below the top of the valence band, setting up coupling and level repulsion at the L point. Furthermore, we find that the topology of the frustrated octahedral structure leads to the occurrence in the random alloy of two distinct bonds for each anion-cation pair and to the predicted stabilization of bulk ordered Pb2STe CuPt-like phase. RP Wei, SH (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Zunger, Alex/A-6733-2013 NR 30 TC 195 Z9 197 U1 2 U2 56 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 MAY 15 PY 1997 VL 55 IS 20 BP 13605 EP 13610 DI 10.1103/PhysRevB.55.13605 PG 6 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000042 ER PT J AU Fluegel, B Zhang, Y Cheong, HM Mascarenhas, A Geisz, JF Olson, JM Duda, A AF Fluegel, B Zhang, Y Cheong, HM Mascarenhas, A Geisz, JF Olson, JM Duda, A TI Exciton absorption bleaching studies in ordered GaxIn1-xP SO PHYSICAL REVIEW B LA English DT Article ID LONG-RANGE-ORDER; SEMICONDUCTOR ALLOYS; OPTICAL-PROPERTIES; GAINP2; BAND; NONLINEARITIES AB Using time-resolved small-signal exciton absorption bleaching at low temperature as a spectroscopic technique, the optical transition energies from all three valence bands in spontaneously ordered GaxIn1-xP have been measured with high accuracy. The origin of the bleaching signal and the contributions of reflection, strain, and binding energy are discussed. With three measured energies from each sample, all parameters in the quasicubic perturbation model can be fitted. Good agreement is obtained with a spin-orbit-splitting parameter of 103 meV, nearly independent of the degree of ordering. The ratio of band-gap reduction to crystal-field-splitting parameter is found to be 2.7, slightly higher than previous works. This difference is attributed to a more accurate determination of light-hole-like band-gap energy. RP Fluegel, B (reprint author), NATL RENEWABLE ENERGY LAB, GOLDEN, CO 80401 USA. RI Cheong, Hyeonsik/D-7424-2012 OI Cheong, Hyeonsik/0000-0002-2347-4044 NR 15 TC 23 Z9 23 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 J9 PHYS REV B JI Phys. Rev. B PD MAY 15 PY 1997 VL 55 IS 20 BP 13647 EP 13650 DI 10.1103/PhysRevB.55.13647 PG 4 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000048 ER PT J AU Turner, DE Zhu, ZZ Chan, CT Mo, KM AF Turner, DE Zhu, ZZ Chan, CT Mo, KM TI Energetics of vacancy and substitution impurities in aluminum bulk and clusters SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC SHELL STRUCTURE; TOTAL-ENERGY CALCULATIONS; 1ST-PRINCIPLES CALCULATION; MOLECULAR-DYNAMICS; LARGE SYSTEMS; METALS; AL; PSEUDOPOTENTIALS; RECONSTRUCTION; MINIMIZATION AB We present a careful study of the energetics of vacancy and substitutional impurities in aluminum in both the bulk and small cluster environments. The calculations are done within the framework of the local-density-functional formalism and are based on the pseudopotential method with plane-wave expansion and periodic boundary conditions. Both the ionic and electronic degrees of freedom are fully relaxed. The electronic structure problem is treated with a preconditioned conjugate-gradient method that applies equally well to insulators and metals, and is suitable for parallel computing. We have considered up to 216 atoms in the supercell, and we show that reliable results can be obtained with 108-atom cells with proper k-point sampling. Vacancy-formation energy, heats of solution of the impurities and the relaxations near the defects air in good agreement with available experimental data. The energetics of substitution in small clusters was found to be rather different from bulk. C1 XIAMEN UNIV,DEPT PHYS,FUJIAN 361005,PEOPLES R CHINA. HONG KONG UNIV SCI & TECHNOL,DEPT PHYS,HONG KONG,HONG KONG. RP Turner, DE (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,US DOE,AMES LAB,AMES,IA 50011, USA. RI Zhu, ZZ/G-4126-2010 NR 36 TC 36 Z9 37 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 MAY 15 PY 1997 VL 55 IS 20 BP 13842 EP 13852 DI 10.1103/PhysRevB.55.13842 PG 11 WC Physics, Condensed Matter SC Physics GA XD170 UT WOS:A1997XD17000076 ER PT J AU Cooper, F Habib, S Kluger, Y Mottola, E AF Cooper, F Habib, S Kluger, Y Mottola, E TI Nonequilibrium dynamics of symmetry breaking in lambda Phi(4) theory SO PHYSICAL REVIEW D LA English DT Article ID QUANTUM-FIELD THEORY; LARGE-N EXPANSION; FINITE-TEMPERATURE; PARTICLE CREATION; POINT-SEPARATION; MODEL; TIME; RENORMALIZATION; APPROXIMATION; EQUILIBRIUM AB The time evolution of O(AT) symmetric lambda(Phi(2))(2) scalar field theory is studied in the large N limit. In this limit the [Phi(i)] mean field and two-point correlation function [Phi(i) Phi(j)] evolve together as a self-consistent closed Hamiltonian system, characterized by a Gaussian density matrix. The static part of the effective Hamiltonian defines the true effective potential U-eff for configurations far From thermal equilibrium. Numerically serving the time evolution equations for energy densities corresponding to a quench in the unstable spinodal region, we find results quite different from what might be inferred from the equilibrium free energy potential F. Typical time evolutions show effectively irreversible energy flow from the coherent mean fields to the quantum fluctuating modes, due to the creation of massless Goldstone bosons near threshold. The plasma frequency and collisionless damping rate of the mean fields are calculated in terms of the particle number density by a linear response analysis and compared with the numerical results. Dephasing of the fluctuations leads also to the growth of an effective entropy and the transition from quantum to classical behavior of the ensemble. In addition to casting some light on fundamental issues of nonequilibrium quantum statistical mechanics, the general framework presented in this work may be applied to a study of the dynamics of second order phase transitions in a wide variety of Landau-Ginsburg systems described by a scalar order parameter. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Cooper, F (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,T-8,MS B285,LOS ALAMOS,NM 87545, USA. NR 52 TC 149 Z9 149 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0556-2821 J9 PHYS REV D JI Phys. Rev. D PD MAY 15 PY 1997 VL 55 IS 10 BP 6471 EP 6503 DI 10.1103/PhysRevD.55.6471 PG 33 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XA969 UT WOS:A1997XA96900063 ER PT J AU Jedamzik, K AF Jedamzik, K TI Primordial black hole formation during the QCD epoch SO PHYSICAL REVIEW D LA English DT Article ID HADRON PHASE-TRANSITION; EARLY UNIVERSE; DENSITY PERTURBATIONS; INFLATION; FLUCTUATIONS; CONSTRAINTS; SPECTRUM; RELICS; MATTER; MASS AB We consider the formation of horizon-size primordial black holes (PBH's) from pre-existing density fluctuations during cosmic phase transitions. It is pointed out that the formation of PBH's should be particularly efficient during the QCD epoch due to a substantial reduction of pressure forces during adiabatic collapse, or equivalently, a significant decrease in the effective speed of sound during the color-confinement transition. Our considerations imply that for generic initial density perturbation spectra PBH mass functions are expected to exhibit a pronounced peak on the QCD-horizon mass scale similar to 1 M.. This mass scale is roughly coincident with the estimated masses for compact objects recently observed in our galactic halo by the MACHO Collaboration. Black holes formed during the QCD epoch may offer an attractive explanation for the origin of halo dark matter evading possibly problematic nucleosynthesis and luminosity bounds on baryonic halo dark matter. C1 LAWRENCE LIVERMORE NATL LAB, INST GEOPHYS & PLANETARY PHYS, PHYS RES PROGRAM, LIVERMORE, CA 94550 USA. NR 43 TC 98 Z9 99 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD MAY 15 PY 1997 VL 55 IS 10 BP R5871 EP R5875 PG 5 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XA969 UT WOS:A1997XA96900001 ER PT J AU Kieft, JS Tinoco, I AF Kieft, JS Tinoco, I TI Solution structure of a metal-binding site in the major groove of RNA complexed with cobalt (III) hexammine SO STRUCTURE LA English DT Article DE cobalt (III) hexammine; metal binding; NMR; RNA structure ID PHENYLALANINE TRANSFER-RNA; HAMMERHEAD RIBOZYME; ION-BINDING; TERTIARY STRUCTURE; CLEAVAGE REACTION; DNA CONDENSATION; HAIRPIN; METALLOBIOCHEMISTRY; STABILIZATION; SPECTROSCOPY AB Background: Solvated metal ions are critical for the proper folding and function of RNA. Despite the importance of these ions, the details of specific metal ion-RNA interactions are poorly understood. The crystal structure of a group I intron ribozyme domain characterized several metal-binding sites in the RNA with osmium (Ill) hexammine bound in the major groove. A corresponding method for locating and characterizing metal-binding sites of RNA in solution is of obvious interest, NMR should be ideal for localizing metal hexammine ions bound to the RNA because of the large concentration of protons around the metal center. Results: We have solved the solution structure of the P5b stem loop from a group I intron ribozyme bound to a cobalt (III) hexammine ion. The location of the ion is precisely determined by intermolecular nuclear Overhausser effect cross-peaks between the cobalt (Ill) hexammine protons and both exchangeable and non-exchangeable RNA protons in the major groove. The binding site consists of tandem G-U base pairs in a sequence of four consecutive G residues ending in a GAAA tetraloop, as originally identified in the crystal structure. The edges of the bases in the major groove present an electrostatically negative face and a variety of hydrogen-bond accepters for the cobalt (Ill) hexammine ion. The metal ion ligand is bound near the guanosine nucleotides of the adjacent G-U base pairs, where it makes hydrogen bonds with the N7 and carbonyl groups of both guanines. The carbonyl groups of the uracil residues add to the negative surface of the binding pocket, but do not form hydrogen bonds with the hexammine. Additional hydrogen bonds form with other guanine residues of the GGGG sequence. The structure of the binding site does not change significantly on binding the cobalt (III) hexammine. The structure of the complex in solution is very similar to the structure in the crystal. Conclusions: The structure presents a picture of how tandem G-U base pairs bind and position metal ions within the RNA major groove. The binding site is preformed in the absence of metal ions, and presents a negative pocket in the major groove with a variety of hydrogen-band accepters. Because G-U base pairs are such a common motif in RNA sequences, it is possible that this RNA-metal ion interaction is critical in forming large complex RNA structures such as those found in the ribosome and self-splicing introns. This structure was determined using cobalt (Ill) hexammine as an analog for hexahydrated magnesium, a technique that may be applicable to other RNA sequences. Metal hexammines may prove to be useful general probes for locating RNA metal ion binding sites in solution. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. FU NIGMS NIH HHS [GM 10840] NR 40 TC 139 Z9 139 U1 0 U2 13 PU CURRENT BIOLOGY LTD PI LONDON PA 34-42 CLEVELAND STREET, LONDON, ENGLAND W1P 6LB SN 0969-2126 J9 STRUCTURE JI Structure PD MAY 15 PY 1997 VL 5 IS 5 BP 713 EP 721 DI 10.1016/S0969-2126(97)00225-6 PG 9 WC Biochemistry & Molecular Biology; Biophysics; Cell Biology SC Biochemistry & Molecular Biology; Biophysics; Cell Biology GA XD041 UT WOS:A1997XD04100012 PM 9195889 ER PT J AU Yang, MX Kash, PW Sun, DH Flynn, GW Bent, BE Holbrook, MT Bare, SR Fischer, DA Gland, JL AF Yang, MX Kash, PW Sun, DH Flynn, GW Bent, BE Holbrook, MT Bare, SR Fischer, DA Gland, JL TI Chemistry of chloroethylenes on Cu(100): Bonding and reactions SO SURFACE SCIENCE LA English DT Article DE alkenes; chemisorption; copper; halides; near edge extended X-ray absorption fine structure (NEXAFS); surface chemical reaction; thermal desorption spectroscopy; work function measurements ID ELECTRON-ENERGY-LOSS; ABSORPTION FINE-STRUCTURE; METHYL HALIDES CL; SHAPE RESONANCES; LOSS SPECTRA; CU(111); ADSORPTION; SURFACES; PT(111); LENGTHS AB The bonding and reactions of chloroethylenes (vinyl chloride, trans- and cis-dichloroethylene, trichloroethylene) on a Cu(100) surface have been investigated by temperature-programmed desorption and reaction, near-edge X-rap absorption fine structure (NEXAFS) studies and measurements of changes of the surface work function. The monolayer molecules adsorb molecularly intact at 95 K via pi coordination. The molecules orient with their molecular planes parallel to the surface with little increase (<0.02 Angstrom) in the C-C bond distance compared with the gas phase values. The degree of thermal dissociation increases with the extent of halogenation, and no chlorine is present in the hydrocarbon reaction products liberated from the surface. Both cis- and trans-1,2-chloroethylene produce acetylene and a small amount of benzene, while dissociation of trichloroethylene generates acetylene and deposits a carbon residue on the surface. Vinyl chloride desorbs from Cu(100) without reaction. (C) 1997 Elsevier Science B.V. C1 DOW CHEM CO USA,MIDLAND,MI 48674. BROOKHAVEN NATL LAB,NATL INST STAND & TECHNOL,NSLS,UPTON,NY 11973. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. RP Yang, MX (reprint author), COLUMBIA UNIV,DEPT CHEM,NEW YORK,NY 10027, USA. NR 31 TC 35 Z9 35 U1 1 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 MAY 15 PY 1997 VL 380 IS 2-3 BP 151 EP 164 DI 10.1016/S0039-6028(96)01002-3 PG 14 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300009 ER PT J AU Chiarello, RP You, H Kim, HK Roberts, T Kempwirth, RT Miller, D Gray, KE Vandervoort, KG Trivedi, N Phillpot, SR Zhang, QJ Williams, S Ketterson, JB AF Chiarello, RP You, H Kim, HK Roberts, T Kempwirth, RT Miller, D Gray, KE Vandervoort, KG Trivedi, N Phillpot, SR Zhang, QJ Williams, S Ketterson, JB TI X-ray reflectivity study on gold films during sputter deposition SO SURFACE SCIENCE LA English DT Article DE atomic force microscopy; gold; growth; metallic films; metallic surfaces; models of non-equilibrium phenomena; nonequilibrium thermodynamics and statistical mechanics; polycrystalline surfaces; polycrystalline thin films; scanning tunneling microscopy; silicon; solid-gas interfaces; sputtering; surface roughening; surface structure, morphology, roughness, and topography; X-ray scattering, diffraction, and reflection ID ON-SOLID MODEL; ROUGH SURFACES; WATER INTERFACE; GROWTH; SCATTERING AB We performed in-situ X-ray reflectivity measurements of gold films during sputter deposition on polished silicon substrates. The measurements were performed at several substrate temperatures and under two argon pressures. The gold surfaces were also examined by scanning tunneling microscopy after deposition to obtain their rear-space topographic images. These images were used to complement the X-ray reflectivity measurements in determining the effect of argon pressure on the gold surface and its height-height difference functions. An approximation for height-height difference functions was employed to analyze the X-ray reflectivity data. The measured interface width during growth followed a simple power law, consistent with recent theoretical results of dynamic scaling behavior. The scaling exponents, however, do not agree well with predictions based on some models in 2 + 1 dimensions. (C) 1997 Elsevier Science B.V. C1 PUSAN NATL UNIV,DEPT PHYS,PUSAN 609735,SOUTH KOREA. NORTHWESTERN UNIV,DEPT PHYS & ASTRON,EVANSTON,IL 60208. RP Chiarello, RP (reprint author), ARGONNE NATL LAB,DIV MAT SCI,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Ketterson, John/B-7234-2009; Phillpot, Simon/J-9117-2012; You, Hoydoo/A-6201-2011; Kim, Hyung-Kook/J-2065-2012; OI You, Hoydoo/0000-0003-2996-9483; Kim, Hyung-Kook/0000-0003-4974-5233; Phillpot, Simon/0000-0002-7774-6535 NR 34 TC 8 Z9 8 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 15 PY 1997 VL 380 IS 2-3 BP 245 EP 257 DI 10.1016/S0039-6028(96)01406-9 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300016 ER PT J AU Graupner, H Hammer, L Heinz, K Zehner, DM AF Graupner, H Hammer, L Heinz, K Zehner, DM TI Oxidation of low-index FeAl surfaces SO SURFACE SCIENCE LA English DT Article DE aluminum; iron; low energy electron diffraction; low index single crystal surfaces; oxidation; x-ray photoelectron spectroscopy ID RAY PHOTOELECTRON-SPECTROSCOPY; ALUMINUM-OXIDE OVERLAYER; TRANSIENT OXIDATION; INITIAL-STAGES; BEHAVIOR; AL2O3; FILMS; XPS AB The oxidation of the (100), (110) and (111) surfaces of the intermetallic compound FeAl has been investigated using LEED and XPS. On all three surfaces, oxidation at room temperature leads to the formation of an amorphous oxide film on top of an Al-depleted interlayer. The him growth can be divided into two regions of differing kinetics, i.e. the initial formation of a closed oxide film and a subsequent thickening In the first region, the oxygen-uptake rate varies significantly with surface orientation, while in the thickening regime the uptake is the same for all surfaces. The maximum thickness as well as the composition of the oxide films were found to depend on the initial oxidation rate. At higher oxidation temperatures, ordered oxide films of around 5-8 Angstrom in thickness are formed, very similar to those observed on NiAl. Photoemission spectra from these ordered phases showed evidence for Al atoms in two different chemical environments, i.e. the well-known oxide species in the interior of the film and an additional species present at the oxide/alloy interface. (C) 1997 Elsevier Science B.V. C1 UNIV ERLANGEN NURNBERG,LEHRSTUHL FESTKORPERPHYS,D-91058 ERLANGEN,GERMANY. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Hammer, Lutz/D-9863-2013 NR 34 TC 64 Z9 65 U1 0 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 MAY 15 PY 1997 VL 380 IS 2-3 BP 335 EP 351 DI 10.1016/S0039-6028(96)01594-4 PG 17 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300024 ER PT J AU Wang, LQ Ferris, KF Shultz, AN Baer, DR Engelhard, MH AF Wang, LQ Ferris, KF Shultz, AN Baer, DR Engelhard, MH TI Interactions of HCOOH with stoichiometric and defective TiO2(110) surfaces SO SURFACE SCIENCE LA English DT Article DE chemisorption; electron bombardment; formic acid; surface electronic phenomena; titanium oxide; ultraviolet and X-ray photoelectron spectroscopy ID FORMIC-ACID DECOMPOSITION; MOLECULAR-ORBITAL METHODS; VALENCE BASIS-SETS; CATALYTIC DECOMPOSITION; ABINITIO CALCULATIONS; 1ST-ROW ELEMENTS; 2ND-ROW ELEMENTS; SINGLE-CRYSTAL; REACTION PATHS; TIO2 AB Interactions of HCOOH with stoichiometric (nearly defect-free) and defective TiO2(110) surfaces have been studied experimentally using X-ray photoelectron spectroscopy (XPS), ultraviolet photoemission spectroscopy (UPS), and theoretically using electronic structure calculations. The HCOOH saturation coverages were 0.58 ML. 0.77 ML, and 0.97 ML (1 ML approximate to 5.2 x 10(14) cm(-2)) for nearly defect-free surfaces, for electron-beam exposed surfaces, and for Ar+ ion bombarded surfaces, respectively, The excess formic acid adsorption quantitatively corresponds to the number of newly exposed sites created by electron-beam exposure. Electronic structure calculations show a strong adsorptive interaction for formate on cation sites on both stoichiometric and defective TiO2 surfaces, consistent with the experimental observations. In spite of adsorption at defect sites, little or no defect healing (defect healing means a reduction in defect signal observed by the photoemission measurements) was observed for either electron-beam exposed or Ar+ bombarded surfaces by HCOOH exposure up to 10(4) L at room temperature. However some healing: will occur if extra energy provided by electrons is introduced to breakdown formate species. In contrast to water adsorption, electronic structure calculations on defective TiO2 have found that formate is located in an asymmetric position with respect to the Ti3+ sites with a potential additional interaction with the Ti4+ site. (C) 1997 Elsevier Science B.V. C1 OREGON STATE UNIV, DEPT PHYS, CORVALLIS, OR 97331 USA. RP Wang, LQ (reprint author), PACIFIC NW LAB, ENERGY & ENVIRONM SCI DIV, POB 999, RICHLAND, WA 99352 USA. RI Engelhard, Mark/F-1317-2010; Baer, Donald/J-6191-2013; OI Baer, Donald/0000-0003-0875-5961; Engelhard, Mark/0000-0002-5543-0812 NR 40 TC 68 Z9 68 U1 4 U2 24 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 15 PY 1997 VL 380 IS 2-3 BP 352 EP 364 DI 10.1016/S0039-6028(97)00023-X PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300025 ER PT J AU Nelson, EJ Kendelewicz, T Liu, P Pianetta, P AF Nelson, EJ Kendelewicz, T Liu, P Pianetta, P TI New surface phases for potassium adatoms on cleaved Si(111) SO SURFACE SCIENCE LA English DT Article DE alkali metals; low energy electron diffraction (LEED); low index single crystal surfaces; metal-semiconductor interfaces; silicon; surface thermodynamics (including phase transitions); work function measurements ID NEGATIVE ELECTRON AFFINITY; STRUCTURAL MODEL; ADSORPTION; RECONSTRUCTION; PHOTOEMISSION; COVERAGE AB In a previous study (B. Reihl and K.O. Magnusson, Phys. Rev. B 42 (1990) 11839) no change was observed in the LEED pattern from the 2x1 pattern of the clean Si(lll) surface upon potassium adsorption, In contrast to this paper, we observe six surface phases during room temperature dosing of K on the cleaved Si(lll) surface. In addition, Ne observe a 3x1 pattern on the cleaved K/Si(111) surface upon annealing. This paper will provide photographs of the new phases observed with LEED. It also will set limits on the K coverage required far these phases using results from photoemission and secondary electron cutoff measurements. Tentative models for these surfaces will be proposed. These new LEED results show a more complex interaction between K and the cleaved Si(111) surface than previously thought and hopefully will encourage further exploration of adsorption on the cleaved Si(lll) surface. (C) 1997 Elsevier Science B.V. C1 STANFORD UNIV,DEPT GEOG & ENVIRONM SCI,STANFORD,CA 94305. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94306. RP Nelson, EJ (reprint author), STANFORD UNIV,DEPT PHYS,STANFORD,CA 94305, USA. NR 18 TC 1 Z9 1 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 15 PY 1997 VL 380 IS 2-3 BP 365 EP 376 DI 10.1016/S0039-6028(97)00024-1 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300026 ER PT J AU Rodriguez, JA Kuhn, M Hrbek, J AF Rodriguez, JA Kuhn, M Hrbek, J TI The interaction of Cu and S-2 with aluminum and alumina surfaces: A comparative study SO SURFACE SCIENCE LA English DT Article DE aluminum; aluminum oxide; copper; metal-insulator interfaces; metal-metal interfaces; photoelectron spectroscopy; sulfur; sulphides ID GAS SHIFT REACTION; X-RAY-ABSORPTION; ELECTRONIC-STRUCTURE; PHOTOELECTRON-SPECTROSCOPY; CHARGE REDISTRIBUTION; ALPHA-ALUMINA; COPPER; FILMS; GROWTH; ALPHA-AL2O3(0001) AB The bonding interactions between Cu and Al are much stronger than those between Cu and Al2O3. Cu atoms supported on alumina show a narrow 3d band with a centroid shifted similar to 0.35 eV with respectto that of the 3d band in bulk metallic Cu. In contrast, Cu atoms deposited on aluminum exhibit shifts of 1.3-1.6 eV in the centroid of,the 3d band. Similar differences are observed when comparing the behavior of Ag and Pt overlayers on alumina and aluminum. The d band shifts on the oxide substrate are in the order of 0.3-0.4 eV, whereas on the metal substrate they vary from 0.8 to 2.0 eV. These trends are explained in terms of a simple model that takes into account changes in the energy of the Al(3s,3p) bands when going from metallic aluminum to alumina. The sticking coefficient of S-2 on alumina surfaces is at least one order of magnitude smaller than on aluminum, a difference that also reflects variations in the position of the Al(3s,3p) bands. Submonolayer coverages of Cu do not produce significant changes in the electronic properties of Al2O3. In contrast, the deposition of small amounts of sulfur (similar to 0.1 ML) induces a substantial reduction (0.4-0.5 eV) in the binding energies of the O KW, O Is and Al 2p features of alumina. This is consistent with a transfer of electrons from alumina into the S atoms that produces a transformation similar to a change from n-type to p-type semiconductors. The reactivity of Cu/(Al2O3)-O-., surfaces toward sulfur is much larger than that of pure Al2O3, surfaces. Cu clusters supported on alumina react with S-2 to form CuSx compounds that decompose at temperatures between 850 and 1100 K. (C) 1997 Elsevier Science B.V. RP Rodriguez, JA (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Hrbek, Jan/I-1020-2013 NR 55 TC 8 Z9 8 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 15 PY 1997 VL 380 IS 2-3 BP 397 EP 407 DI 10.1016/S0039-6028(97)00032-0 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300029 ER PT J AU Struck, LM Eng, J Bent, BE Flynn, GW Chabal, YJ Christman, SB Chaban, EE Raghavachari, K Williams, GP Radermacher, K Mantl, S AF Struck, LM Eng, J Bent, BE Flynn, GW Chabal, YJ Christman, SB Chaban, EE Raghavachari, K Williams, GP Radermacher, K Mantl, S TI Vibrational study of silicon oxidation: H2O on Si(100) SO SURFACE SCIENCE LA English DT Article DE ab initio quantum chemical methods and calculations; ion implantation; low index single crystal surfaces; oxidation; reflection spectroscopy; silicides; silicon; silicon oxides; vibrations of adsorbed molecules; water ID REFLECTION ABSORPTION-SPECTROSCOPY; SURFACE; SI(111); CHEMISORPTION; SI; ADSORPTION; WATER; H-2 AB The vibrational spectrum of water dissociatively adsorbed on Si(100) surfaces is obtained with surface infrared absorption spectroscopy. Low frequency spectra(< 1450 cm(-1)) are acquired using a buried CoSi2 layer as an internal mirror to perform external reflection spectroscopy. On clean Si(100), water dissociates into H and OH surface species as evidenced by EELS results [1] in the literature which show a Si-H stretching vibration (2082 cm(-1)). and Si-O-H vibrations (O-H stretch at 3660 cm(-1) and the Si-O-H bend and Si-O stretch of the hydroxyl group centered around 820 cm(-1)). In this paper, infrared (IR) measurements are presented which confirm and resolve the issue of a puzzling isotopic shift for the Si-O mode of the surface hydroxyl group, namely, that the Si-O stretch of the -OH surface species formed upon H2O exposure occurs at 825 cm(-1), while the Si-O stretch of the -OD surface species formed upon D2O exposure shifts to 840 cm(-1), contrary to what is expected for simple reduced mass arguments. The higher resolution of IR measurements versus typical EELS measurements makes it possible to identify a new mode at 898 cm(-1)? which is an important piece of evidence in understanding the anomalous frequency shift. By comparing the results of measurements for adsorption of (H2O)-O-16, (H2O)-O-18 and D2O with the results from recently performed first-principles calculations, it can be shown that a strong vibrational interaction between the Si-O stretching and Si-O-H bending functional group vibrations of the hydroxyl group accounts for the observed isotopic shifts. (C) 1997 Elsevier Science B.V. C1 AT&T BELL LABS, LUCENT TECHNOL, MURRAY HILL, NJ 07974 USA. COLUMBIA UNIV, DEPT CHEM, NEW YORK, NY 10027 USA. COLUMBIA UNIV, COLUMBIA RADIAT LAB, NEW YORK, NY 10027 USA. BROOKHAVEN NATL LAB, UPTON, NY 11973 USA. FORSCHUNGSZENTRUM JULICH, FORSCHUNGSZENTRUM, INST SCHICHT & IONENTECH, D-5170 JULICH, GERMANY. RI Chabal, Yves/A-5998-2011; Mantl, Siegfried/L-1317-2013 OI Chabal, Yves/0000-0002-6435-0347; Mantl, Siegfried/0000-0002-4266-0619 NR 28 TC 51 Z9 51 U1 2 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD MAY 15 PY 1997 VL 380 IS 2-3 BP 444 EP 454 DI 10.1016/S0039-6028(97)00041-1 PG 11 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300034 ER PT J AU Mullins, DR Huntley, DR Tang, T Saldin, DK Tysoe, WT AF Mullins, DR Huntley, DR Tang, T Saldin, DK Tysoe, WT TI The adsorption site and orientation of CH3S on Ni(111) SO SURFACE SCIENCE LA English DT Article DE chemisorption; nickel; photoelectron diffraction; soft X-ray photoelectron spectroscopy; sulfur ID PHOTOELECTRON DIFFRACTION; SURFACE RECONSTRUCTION; (5-ROOT-3X2)S PHASE; METHYL THIOLATE; ION-SCATTERING; METHANETHIOL; SULFUR; DECOMPOSITION; NICKEL; CHEMISORPTION AB The angle-resolved X-ray photoelectron spectra for 0.15 monolayers (ML) of sulfur, and 0.25 ML methyl thiolate formed at 100 K and annealed to 150 and 250 K, on Ni(lll) are analyzed to determine the structures of these species. It is found that sulfur adsorbs on the face-centered cubic hollow site on Ni(111) with a S-Ni bond length of 2.20 +/- 0.02 Angstrom. The thiolate species formed at 150 K has the C-S bond tilted at similar to 35 degrees to the surface normal with a C-S bond length of 1.85 +/- 0.02. Angstrom and a S-Ni bond length similar to that for adsorbed sulfur (2.2 Angstrom). The methyl group is tilted toward the bridge site and the thiolate appears to be adsorbed on the face-centered cubic site although there may also be adsorption in the hexagonal close packed site. The species formed at 250 K adsorbs on a reconstructed surface where the chemical shift of the S 2p core level indicates that it adsorbs at a four-fold site and the angle-resolved XPS data indicate that the C-S bond is oriented normal to the surface. The calculated angular variations in intensity are consistent with this interpretation but cannot distinguish between the various models proposed for the reconstructed surface. (C) 1997 Elsevier Science B.V. C1 UNIV WISCONSIN,DEPT CHEM,MILWAUKEE,WI 53211. UNIV WISCONSIN,SURFACE STUDIES LAB,MILWAUKEE,WI 53211. UNIV WISCONSIN,DEPT PHYS,MILWAUKEE,WI 53211. RP Mullins, DR (reprint author), OAK RIDGE NATL LAB,OAK RIDGE,TN 37831, USA. NR 33 TC 27 Z9 27 U1 0 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 MAY 15 PY 1997 VL 380 IS 2-3 BP 468 EP 480 DI 10.1016/S0039-6028(97)00044-7 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA XF843 UT WOS:A1997XF84300036 ER PT J AU Vispute, RD Narayan, J Budai, JD AF Vispute, RD Narayan, J Budai, JD TI High quality optoelectronic grade epitaxial AlN films on alpha-Al2O3, Si and 6H-SiC by pulsed laser deposition SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 23rd International Conference on Metallurgical Coatings and Thin Films CY APR 22-26, 1996 CL SAN DIEGO, CA SP Amer Vacuum Soc, Vacuum Met & Thin Films Div DE aluminum nitride; epitaxy; growth mechanism; laser ablation ID CHEMICAL-VAPOR-DEPOSITION; MOLECULAR-BEAM EPITAXY; NITRIDE THIN-FILMS; ALUMINUM NITRIDE; A1N FILMS; BAND-GAP; GROWTH; SAPPHIRE; AIN; ABLATION AB AlN is one of the most important optoelectronic materials in the wide hand gap LII-V semiconductors because of its wide and tunable energy band gap in conjunction with other nitrides, high thermal conductivity, doping capabilities, and high hardness. The proposed optoelectronic devices require high quality epitaxial films on various substrates. Here, we present our recent work on the fabrication of high quality epitaxial AlN films on Al2O3(0001), Si(lll) and 6H-SiC(0001) by pulsed laser deposition (PLD). The PLD is a nonequilibrium technique where thin film growth temperature can be reduced by more than 250-350 degrees C and epitaxial films comparable in quality to MOCVD (equilibrium technique) obtained. The laser fluence and the substrate temperature were found to be crucial processing parameters for the formation of high quality monocrystalline AlN films. The AlN films deposited above 750 degrees C and laser energy densities of 2-3 J cm(-2) were found to be epitaxial with c-axis normal to substrate plane. The X-ray rocking curve of epitaxial films on sapphire and SiC yielded full-width-at-half-maximum of similar to 0.06-0.07 degrees. The transmission electron microscopy also revealed that the films were epitaxial with an orientational relationship of AlN[0001]parallel to Al2O3[0001], AlN[0001]parallel to Si[111], AlN[0001]parallel to SiC[0001] and in-plane alignment of AlN[<(1)over bar 2><(1)over bar 0>]parallel to Al2O3[<0(1)over bar 10>], AlN[<10(1)over bar 0>]parallel to Al2O3[<(2)over bar 110>], AlN[<2(11)over bar 0>]parallel to Si[01(1) over bar] and AlN[<0(1)over bar 10>]parallel to SiC[<0(1)over bar 10>]. The optical absorption edge measured by UV-visible spectroscopy for the epitaxial AlN film on sapphire was sharp and the band gap was found to be 6.1 eV. The electrical resistivity of the films was about 5-6 x 10(13) Omega cm(-1) with a breakdown field of 5 x 10(6) V cm(-1). (C) 1997 Elsevier Science S.A. C1 N CAROLINA STATE UNIV,DEPT MAT SCI & ENGN,RALEIGH,NC 27695. OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. RI Narayan, Jagdish/D-1874-2009; Budai, John/R-9276-2016 OI Budai, John/0000-0002-7444-1306 NR 41 TC 44 Z9 46 U1 4 U2 17 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 15 PY 1997 VL 299 IS 1-2 BP 94 EP 103 DI 10.1016/S0040-6090(96)09395-9 PG 10 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XH325 UT WOS:A1997XH32500018 ER PT J AU Medlin, DL McCarty, KF Hwang, RQ Guthrie, SE Baskes, MI AF Medlin, DL McCarty, KF Hwang, RQ Guthrie, SE Baskes, MI TI Orientation relationships in heteroepitaxial aluminum films on sapphire SO THIN SOLID FILMS LA English DT Article DE aluminium; aluminium oxide; electron microscopy; epitaxy ID GROWTH AB We investigate the microstructure and orientation relationships observed in aluminum thin films deposited epitaxially on sapphire (0001). The films consist of grains with three distinct types of orientation relative to the substrate. The primary orientation is such that (0001)(Al2O3)parallel to(111)(Al) and [<10(1)over bar 0>](Al2O3)parallel to[<(1)over bar 10>](Al). This configuration, which matches the close-packed planes and directions of the metal film with those of the oxygen ion sublattice in the sapphire substrate, allows for growth of two symmetrically equivalent orientation variants resulting in a film composed of interlocking regions of these two domains. Unexpectedly, two additional orientation types are identified in the films. As in the primary variant, the close-packed aluminum (111) planes remain parallel with the sapphire basal planes. However, these orientations are rotated about the aluminum [111] axis such that [<10(1)over bar 0>](Al2O3) is parallel to directions near either [<(1)over bar 2>(1) over bar](Al) (30 degrees rotation) or [<5(41)over bar>](Al) (similar to 11 degrees rotation). (C) 1997 Elsevier Science S.A. RP Medlin, DL (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. RI McCarty, Kevin/F-9368-2012 OI McCarty, Kevin/0000-0002-8601-079X NR 9 TC 48 Z9 48 U1 2 U2 11 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 15 PY 1997 VL 299 IS 1-2 BP 110 EP 114 DI 10.1016/S0040-6090(96)09393-5 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XH325 UT WOS:A1997XH32500020 ER PT J AU Jia, QX Kung, HH Wu, XD AF Jia, QX Kung, HH Wu, XD TI Microstructure properties of Ba0.5Sr0.5TiO3 thin films on Si with conductive SrRuO3 bottom electrodes SO THIN SOLID FILMS LA English DT Article DE capacitors; dielectrics; laser ablation; structural properties ID ELECTRICAL-PROPERTIES; LASER-ABLATION; DIELECTRIC-PROPERTIES; EPITAXIAL-GROWTH; (BA; (BA0.5,SR0.5)TIO3; HETEROSTRUCTURES; DEPOSITION; CONSTANT AB Quaternary Ba0.5Sr0.5TiO3 (BSTO) thin films were deposited on (100) Si by pulsed laser deposition with conductive SrRuO3 (SRO) bottom electrodes. The growth of highly (001)-oriented SRO film on (100) Si was accomplished by using a bilayer buffer CeO2 and yttria-stabilized zirconia (YSZ). The BSTO films deposited on SRO on Si using such a buffer system were well aligned in the plane with respect to the major axes of the substrate confirmed by X-ray diffraction. The crystalline nature of the BSTO films on Si was further illustrated by Rutherford backscattering spectrometry and cross-sectional transmission electron microscopy. The BSTO thin films exhibited a dielectric constant above 340 at 10 kHz tested from a capacitor configuration of Au/BSTO/SRO. (C) 1997 Elsevier Science S.A. RP Jia, QX (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,MAIL STOP G755,LOS ALAMOS,NM 87545, USA. RI Jia, Q. X./C-5194-2008 NR 27 TC 19 Z9 19 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD MAY 15 PY 1997 VL 299 IS 1-2 BP 115 EP 118 DI 10.1016/S0040-6090(96)09448-5 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA XH325 UT WOS:A1997XH32500021 ER PT J AU Malm, JO OKeefe, MA AF Malm, JO OKeefe, MA TI Deceptive ''lattice spacings'' in high-resolution micrographs of metal nanoparticles SO ULTRAMICROSCOPY LA English DT Article DE high-resolution transmission electron microscopy; catalysts; simulation; tilt; nanoparticles ID ELECTRON-MICROSCOPY; PD PARTICLES; CLUSTERS AB Experimental HRTEM images of randomly oriented nanocrystals typically show fringes within the nanocrystals. Often these fringes are one-dimensional, although many appear to show two-dimensional resolution. In order to determine the tilt conditions necessary for the formation of one- and two-dimensional fringes in metal nanocrystals, simulations of HRTEM images of a 561-atom palladium nanoparticle were systematically carried out over an extensive range of tilts. The resultant images contained fringes that are deceptively like one- and two-dimensional lattice fringes. These fringes are, however, not simply related to the crystal structure of the particle, and ''lattice spacings'' measured from them will be in error. In addition, depending upon particle orientation, HRTEM images of a perfect nanoparticle can show details that may be erroneously interpreted as ''relaxations'', ''bent planes'', and even ''twinned'' areas. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,NATL CTR ELECTRON MICROSCOPY,BERKELEY,CA 94720. NR 22 TC 58 Z9 58 U1 1 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3991 J9 ULTRAMICROSCOPY JI Ultramicroscopy PD MAY 15 PY 1997 VL 68 IS 1 BP 13 EP 23 DI 10.1016/S0304-3991(97)00005-3 PG 11 WC Microscopy SC Microscopy GA XJ575 UT WOS:A1997XJ57500002 ER PT J AU Rompel, A Andrews, JC Cinco, RM Wemple, MW Christou, G Law, NA Pecoraro, VL Sauer, K Yachandra, VK Klein, MP AF Rompel, A Andrews, JC Cinco, RM Wemple, MW Christou, G Law, NA Pecoraro, VL Sauer, K Yachandra, VK Klein, MP TI Chlorine K-edge X-ray absorption spectroscopy as a probe of chlorine-manganese bonding: Model systems with relevance to the oxygen evolving complex in photosystem II SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID PHOTOSYNTHETIC WATER OXIDATION; METAL; COVALENCY; CALCIUM; IONS; EVOLUTION AB For a series of Mn-Cl coordination complexes the chlorine K-edge X-ray absorption spectra (XAS) have been measured to probe chloride-manganese bonding. Results show that in a series of mononuclear (single Mn) compounds with Cl covalently bound to Mn, the intensity of the pre-edge feature increases in the order Mn-II < Mn-III < Mn-IV. For a series of distorted cubane complexes (containing 4 Mn) with bridging and terminal Cl Ligands, three pre-edge features are seen. The pre-edge peak at lowest energy increases in intensity as more terminal Cl are included in the compounds. The origin of these features in the edge spectra is described in terms of the symmetry and ligand field splittings expected for the Mn complexes. The Mn model systems studied here have potential application to the oxygen evolving complex (OEC) in Photosystem II (PSII), where direct structural evidence for a halide binding site on the Mn cluster in one or more S-states of the Kok cycle would be informative. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,STRUCT BIOL DIV,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. INDIANA UNIV,DEPT CHEM,BLOOMINGTON,IN 47405. UNIV MICHIGAN,DEPT CHEM,ANN ARBOR,MI 48109. RI pecoraro, vincent/B-7094-2008; Christou, George /A-3072-2014 OI pecoraro, vincent/0000-0002-1540-5735; NR 20 TC 25 Z9 25 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 MAY 14 PY 1997 VL 119 IS 19 BP 4465 EP 4470 DI 10.1021/ja9610951 PG 6 WC Chemistry, Multidisciplinary SC Chemistry GA WZ081 UT WOS:A1997WZ08100017 ER PT J AU Fujita, E Furenlid, LR Renner, MW AF Fujita, E Furenlid, LR Renner, MW TI Direct XANES evidence for charge transfer in Co-CO2 complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID CARBON-DIOXIDE ACTIVATION; WATER GAS SHIFT; HOMOGENEOUS CATALYSIS; COBALT(I) MACROCYCLES; CRYSTAL-STRUCTURES; COORDINATION MODE; METAL-CARBONYLS; ABINITIO MO; CO2; REDUCTION C1 BROOKHAVEN NATL LAB,NATL SYNCHROTRON LIGHT SOURCE,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT APPL SCI,UPTON,NY 11973. RP Fujita, E (reprint author), BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973, USA. RI Fujita, Etsuko/D-8814-2013 NR 25 TC 38 Z9 38 U1 1 U2 21 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 MAY 14 PY 1997 VL 119 IS 19 BP 4549 EP 4550 DI 10.1021/ja970151a PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WZ081 UT WOS:A1997WZ08100032 ER PT J AU Carrado, KA Zajac, GW Song, K Brenner, JR AF Carrado, KA Zajac, GW Song, K Brenner, JR TI Crystal growth of organohectorite clay as revealed by atomic force microscopy SO LANGMUIR LA English DT Article ID HYDROTHERMAL CRYSTALLIZATION; DISSOLUTION; PARTICLES; SURFACES; AFM; RESOLUTION; MUSCOVITE; MICA AB Noncontact atomic force microscopy, commonly referred to as ''tapping mode'' AFM, has been used to scan primarily the morphological features of growing hectorite clay crystallites synthesized in the presence of organoammonium cations. The use of such cations allows larger crystals to form in this system, making study by AFM feasible. This is the first time that temporal ''snapshots'' of a clay's nucleation and crystallization processes have been presented. The observed view does not support the perhaps predicted scene of small crystallites slowly ripening into large plates. Instead, larger aggregates appear to coalesce from numerous small crystallites that are closely associated in globular networks similar in appearance to ''strings of pearls'' at the initial stages of crystallization. C1 AMOCO CORP, AMOCO RES CTR, NAPERVILLE, IL 60566 USA. RP Carrado, KA (reprint author), ARGONNE NATL LAB, DIV CHEM, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 52 TC 18 Z9 19 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD MAY 14 PY 1997 VL 13 IS 10 BP 2895 EP 2902 DI 10.1021/la961048m PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ447 UT WOS:A1997WZ44700047 ER PT J AU Dearborn, DSP Schramm, DN AF Dearborn, DSP Schramm, DN TI Is there a Population II analogy to the F star lithium dip? SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID SEQUENCE MASS-LOSS; HALO-STARS; PRIMORDIAL LITHIUM; STELLAR EVOLUTION; CLUSTER; ABUNDANCES; MODELS; NUCLEOSYNTHESIS; CONSTRAINTS; COSMOLOGY AB Observers have found a small number of lithium-depleted halo stars in the temperature range of the Spite plateau, The current status of the mass-loss hypothesis for producing the observed lithium dip in Population (Pop) I stars is briefly discussed and extended to Pop II stars as a possible explanation for these halo objects, Based on detections of F-type main-sequence variables, mass loss is assumed to occur in a narrow temperature region corresponding to this ''instability strip.'' As Pop II main-sequence stars evolve to the blue, they enter this narrow temperature region, then move back through the lower temperature area of the Spite plateau, If 0.05 M. (solar mass) or more have been lost, they will show lithium depletion, This hypothesis affects the lithium-to-beryllium abundance, the ratio of high- to low-lithium stars, and the luminosity function, Constraints on the mass-loss hypothesis due to these effects are discussed, Finally, mass loss in this temperature range would operate in stars near the turnoff of metal-poor globular clusters, resulting in apparent ages 2 to 3 Gyr (gigayears) older than they actually are. C1 UNIV CHICAGO, CHICAGO, IL 60637 USA. FERMILAB NATL ACCELERATOR LAB, BATAVIA, IL 60510 USA. RP Dearborn, DSP (reprint author), LAWRENCE LIVERMORE NATL LAB, L-58, POB 808, LIVERMORE, CA 94550 USA. NR 44 TC 1 Z9 1 U1 0 U2 0 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 13 PY 1997 VL 94 IS 10 BP 4836 EP 4841 DI 10.1073/pnas.94.10.4836 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ257 UT WOS:A1997WZ25700006 PM 11038540 ER PT J AU Kupferman, R Tadmor, E AF Kupferman, R Tadmor, E TI A fast, high resolution, second-order central scheme for incompressible flows SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE hyperbolic conservation laws; second-order accuracy; central difference schemes; nonoscillatory schemes ID HYPERBOLIC CONSERVATION-LAWS; RIEMANN SOLVERS; SIMULATIONS AB A high resolution, second-order central difference method for incompressible flows is presented, The method is based on a recent second-order extension of the classic Lax-Friedrichs scheme introduced for hyperbolic conservation laws (Nessyahu H, & Tadmor E, (1990) J. Comp. Physics, 87, 408-463; Jiang G,-S, & Tadmor E, (1996) UCLA CAM Report 96-36, SIAM J, Sci, Comput., in press) and augmented by a new discrete Hedge projection, The projection is exact, yet the discrete Laplacian operator retains a compact stencil, The scheme is fast, easy to implement, and readily generalizable. Its performance was tested on the standard periodic double shear-layer problem; no spurious vorticity patterns appear when the flow is underresolved. A short discussion of numerical boundary conditions is also given, along with a numerical example. C1 TEL AVIV UNIV, SCH MATH SCI, IL-69978 TEL AVIV, ISRAEL. UNIV CALIF LOS ANGELES, DEPT MATH, LOS ANGELES, CA 90095 USA. RP UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DEPT MATH, 1 CYCLOTRON RD, 50A-2152, BERKELEY, CA 94720 USA. OI Tadmor, Eitan/0000-0001-7424-6327 NR 24 TC 25 Z9 25 U1 0 U2 1 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD MAY 13 PY 1997 VL 94 IS 10 BP 4848 EP 4852 DI 10.1073/pnas.94.10.4848 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ257 UT WOS:A1997WZ25700008 PM 11038542 ER PT J AU Cahoon, EB Lindqvist, Y Schneider, G Shanklin, J AF Cahoon, EB Lindqvist, Y Schneider, G Shanklin, J TI Redesign of soluble fatty acid desaturases from plants for altered substrate specificity and double bond position SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article DE unsaturated fatty acid; diiron; nonheme iron; rational design; protein engineering ID CARRIER-PROTEIN DESATURASE; THUNBERGIA-ALATA ENDOSPERM; TRANSGENIC TOBACCO; METABOLISM; SAFFLOWER; PRODUCTS AB Acyl-acyl carrier protein (ACP) desaturases introduce double bonds at specific positions in fatty acids of defined chain lengths and are one of the major determinants of the monounsaturated fatty acid composition of vegetable oils, Mutagenesis studies were conducted to determine the structural basis for the substrate and double bond positional specificities displayed by acyl-ACP desaturases. By replacement of specific amino acid residues in a Delta(6)-palmitoyl (16:0)-ACP desaturase with their equivalents from a Delta(9)-stearoyl (18:0)-ACP desaturase, mutant enzymes were identified that have altered fatty acid chain-length specificities or that can insert double bonds into either the Delta(6) or Delta 9 positions of 16:0- and 18:0-ACP. Most notably, by replacement of five amino acids (A181T/A200F/S205N/L206T/G207A), the Delta(6)-16:0-ACP desaturase was converted into an enzyme that functions principally as a Delta(9)-18:0-ACP desaturase. Many of the determinants of fatty acid chain-length specificity in these mutants are found in residues that line the substrate binding channel as revealed by x-ray crystallography of the Delta(9)-18:0-ACP desaturase. The crystallographic model of the active site is also consistent with the diverged activities associated with naturally occurring variant acyl-ACP desaturases, In addition, on the basis of the active-site model, a Delta(9)-18:0-ACP desaturase was converted into an enzyme with substrate preference for 16:0-ACP by replacement of two residues (L118F/P179I), These results demonstrate the ability to rationally modify acyl-ACP desaturase activities through site-directed mutagenesis and represent a first step toward the design of acyl-ACP desaturases for the production of novel monounsaturated fatty acids in transgenic oilseed crops. C1 BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. KAROLINSKA INST,DEPT MED BIOCHEM & BIOPHYS,S-17177 STOCKHOLM,SWEDEN. RI Lindqvist, Ylva/F-9009-2010 NR 22 TC 107 Z9 114 U1 1 U2 15 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 MAY 13 PY 1997 VL 94 IS 10 BP 4872 EP 4877 DI 10.1073/pnas.94.10.4872 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ257 UT WOS:A1997WZ25700012 PM 9144157 ER PT J AU Trent, JD Kagawa, HK Yaoi, T Olle, E Zaluzec, NJ AF Trent, JD Kagawa, HK Yaoi, T Olle, E Zaluzec, NJ TI Chaperonin filaments: The archaeal cytoskeleton? SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID T-COMPLEX POLYPEPTIDE-1; HEAT-SHOCK; MOLECULAR CHAPERONES; THERMOPHILIC ARCHAEBACTERIUM; THERMOPLASMA-ACIDOPHILUM; SULFOLOBUS-SOLFATARICUS; YEAST TCP1; IN-VIVO; PROTEIN; ACTIN AB Chaperonins are high molecular mass double-ring structures composed of 60-kDa protein subunits. In the hyperthermophilic archaeon Sulfolobus shibatae the two chaperonin proteins represent approximate to 4% of its total protein and have a combined intracellular concentration of >30 mg/ml. At concentrations greater than or equal to 0.5 mg/ml purified chaperonins form filaments in the presence of Mg2+ and nucleotides. Filament formation requires nucleotide binding (not hydrolysis), and occurs at physiological temperatures in biologically relevant buffers, including a buffer made from cell extracts. These observations suggest that chaperonin filaments may exist in vivo and the estimated 4600 chaperonins per cell suggest that such filaments could form an extensive cytostructure. We observed filamentous structures in unfixed, uranyl-acetate-stained S. shibatae cells, which resemble the chaperonin filaments in size and appearance. ImmunoGold (Janssen) labeling using chaperonin antibodies indicated that many chaperonins are associated with insoluble cellular structures and these structures appear to be filamentous in some areas, although they could not be uranyl-acetate-stained. The existence of chaperonin filaments in vivo suggests a mechanism whereby their protein-folding activities can be regulated. More generally, the filaments themselves may play a cytoskeletal role in Archaea. C1 ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Trent, JD (reprint author), ARGONNE NATL LAB,CTR MECHANIST BIOL & BIOTECHNOL,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 43 TC 78 Z9 79 U1 1 U2 4 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 MAY 13 PY 1997 VL 94 IS 10 BP 5383 EP 5388 DI 10.1073/pnas.94.10.5383 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WZ257 UT WOS:A1997WZ25700101 PM 9144246 ER PT J AU Felton, JS Malfatti, MA Knize, MG Salmon, CP Hopmans, EC Wu, RW AF Felton, JS Malfatti, MA Knize, MG Salmon, CP Hopmans, EC Wu, RW TI Health risks of heterocyclic amines SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article; Proceedings Paper CT 6th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-08, 1995 CL MONTEREY, CA SP Flavor & Extract Manufacturers Assoc US, Int Flavors & Fragrances Inc, Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, US FDA, Natl Ctr Toxicol Res, NCI, NIEHS, Nestle S A, Toronto Res Chem Inc ID FOOD MUTAGEN 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE; COOKED FOODS; HEPATIC MICROSOMES; AROMATIC-AMINES; ACTIVATION; CANCER; PHIP; MEAT; DNA; ACETYLATION AB Common cooking procedures such as broiling, frying, barbecuing (flame-grilling), heat processing and pyrolysis of protein-rich foods induce the formation of potent mutagenic and carcinogenic heterocyclic amines. These same compounds produce tumors at multiple organ sites in both mice and rats. One example of these induced tumors has also been seen in nonhuman primates. Risk assessment for the human population consuming these compounds requires the integration of knowledge of dosimetry, metabolism, carcinogenic potency, and epidemiology. When this integration is done in even a preliminary way as is done here, the range of risk for an individual from these compounds is enormous. Exposure contributes a range of 200-fold or more and metabolism and DNA repair differences among individuals could easily be an additional 10-fold between individuals. This indicates that differences in human cancer risk for heterocyclic amines could range more than a thousandfold between individuals based on exposure and genetic susceptibility. RP Felton, JS (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL PROGRAM,L-452,LIVERMORE,CA 94551, USA. FU NCI NIH HHS [CA55861] NR 25 TC 91 Z9 94 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAY 12 PY 1997 VL 376 IS 1-2 BP 37 EP 41 DI 10.1016/S0027-5107(97)00023-7 PG 5 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XE489 UT WOS:A1997XE48900007 PM 9202736 ER PT J AU Hatch, FT Colvin, ME AF Hatch, FT Colvin, ME TI Quantitative structure-activity (QSAR) relationships of mutagenic aromatic and heterocyclic amines SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article; Proceedings Paper CT 6th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-08, 1995 CL MONTEREY, CA SP Flavor & Extract Manufacturers Assoc US, Int Flavors & Fragrances Inc, Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, US FDA, Natl Ctr Toxicol Res, NCI, NIEHS, Nestle S A, Toronto Res Chem Inc DE cooked food mutagen; molecular orbital; quantum mechanics; Huckel; semi-empirical; ab initio ID CARCINOGENS; FOOD AB We extended our previous studies of mutagenic/carcinogenic heterocyclic aromatic amines formed during the cooking of foods to 66 aromatic and 99 heterocyclic amines for which mutagenic potency data are available. The amines require activation by enzymes to form metabolites reactive with DNA and exhibit an enormous range of potency as frameshift mutagens in the Ames/Salmonella assay. To ascertain factors that might influence potency, structural features and quantum mechanical parameters calculated by the Huckel method (and, for a subset of 20 amines, by semi-empirical AM1, and ab initio methods) were analyzed by multiple linear regression. The major findings were: (1) earlier findings on cooked food mutagens and their synthetic congeners can be extended to other amines; (2) mutagenic potency is directly related to the number of fused aromatic rings (size of the aromatic system), the number of ring nitrogen atoms (participation of lone electron pairs in the pi-cloud), and presence of a methyl substituent on a ring nitrogen; (3) potency is inversely related to the energy of the lowest unoccupied molecular orbital (LUMO) of the parent amine. Ford and Griffin (1992) and Sabbioni and Wild (1992) showed that the LUMO energy of the derived nitrenium ion is closely related to its stability (calculated with reference to aniline). Increased stability has been hypothesized to enhance the probability of adduct formation with DNA by avoiding detoxifying side reactions and increasing the lifetime of the ion. In the large heterogeneous series of amines in our present study the Huckel method energy of the highest occupied molecular orbital (HOMO), rather than the LUMO energy, of the nitrenium ion was marginally related to the potency of the parent amine. However, in the selected subset of 20 amines with ab initio calculation, the LUMO energy of the ion confirmed the previous reports. The contribution of quantum chemical factors to mechanistic insight on the mutagenicity and carcinogenicity of aromatic and heterocyclic amines is still under development. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. SANDIA NATL LABS,CTR COMPUTAT ENGN,LIVERMORE,CA 94551. FU NCI NIH HHS [P01 CA55861] NR 20 TC 35 Z9 35 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAY 12 PY 1997 VL 376 IS 1-2 BP 87 EP 96 DI 10.1016/S0027-5107(97)00029-8 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XE489 UT WOS:A1997XE48900013 PM 9202742 ER PT J AU Knize, MG Salmon, CP Mehta, SS Felton, JS AF Knize, MG Salmon, CP Mehta, SS Felton, JS TI Analysis of cooked muscle meats for heterocyclic aromatic amine carcinogens SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article; Proceedings Paper CT 6th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-08, 1995 CL MONTEREY, CA SP Flavor & Extract Manufacturers Assoc US, Int Flavors & Fragrances Inc, Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, US FDA, Natl Ctr Toxicol Res, NCI, NIEHS, Nestle S A, Toronto Res Chem Inc ID MASS-SPECTROMETRY; BEEF EXTRACT; FRIED BEEF; MUTAGENS; PRODUCTS; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE; FISH; 2-AMINO-3,4,8-TRIMETHYLIMIDAZO<4,5-F>QUINOXALINE; 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE; IDENTIFICATION AB A number of related heterocyclic amines that are mutagenic in bacterial test systems and carcinogenic in animals are formed during the cooking of food. The most commonly reported and abundant compounds are PhIP, MeIQx, DiMeIQx, IQ and A alpha C. Using analysis by solid-phase extraction and HPLC, amounts found in foods range from less than one ng/g for products from fast-food restaurants, up to 14 ng/g in commercially cooked products and over 300 ng/g for well done flame-grilled chicken breast meat. Interestingly, marinating meat for 4 h greatly reduces the amount of PhIP produced during cooking, but not MeIQx. Comparing mutagenic activity in meat samples to the mutagenic activity accounted for by the known heterocyclic amines shows that most samples have activity that cannot be accounted for by the aromatic amines we can currently identify. This suggests that additional compounds are present in these foods and need to be investigated, particularly those grilled over open flames. RP Knize, MG (reprint author), LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94550, USA. FU NCI NIH HHS [YO1CP2-0523-01, CA55861] NR 30 TC 41 Z9 43 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAY 12 PY 1997 VL 376 IS 1-2 BP 129 EP 134 DI 10.1016/S0027-5107(97)00035-3 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XE489 UT WOS:A1997XE48900019 PM 9202748 ER PT J AU Snyderwine, EG Turesky, RJ Turteltaub, KW Davis, CD Sadrieh, N Schut, HAJ Nagao, M Sugimura, T Thorgeirsson, UP Adamson, RH Thorgeirsson, SS AF Snyderwine, EG Turesky, RJ Turteltaub, KW Davis, CD Sadrieh, N Schut, HAJ Nagao, M Sugimura, T Thorgeirsson, UP Adamson, RH Thorgeirsson, SS TI Metabolism of food-derived heterocyclic amines in nonhuman primates SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article; Proceedings Paper CT 6th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-08, 1995 CL MONTEREY, CA SP Flavor & Extract Manufacturers Assoc US, Int Flavors & Fragrances Inc, Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, US FDA, Natl Ctr Toxicol Res, NCI, NIEHS, Nestle S A, Toronto Res Chem Inc DE metabolism; IQ; MeIQx; PhIP; food carcinogen; DNA adducts ID DNA ADDUCT LEVELS; CYNOMOLGUS MONKEYS; 2-AMINO-1-METHYL-6-PHENYLIMIDAZO<4,5-B>PYRIDINE PHIP; 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE MEIQX; MUTAGEN 2-AMINO-3-METHYLIMIDAZO<4,5-F>QUINOLINE; COOKED FOODS; ACTIVATION; IQ; CARCINOGEN; MICROSOMES AB During the cooking of meats, several highly mutagenic heterocyclic amines (HCAs) are produced. Three HCAs, IQ, MeIQx, and PhIP have been under study for carcinogenicity in cynomolgus monkeys, and to date, IQ has been shown to be a potent hepatocarcinogen. Concomitantly, the metabolic processing of these HCAs has been examined. Metabolism studies show that the potent hepatocarcinogenicity of IQ is associated with the in vivo metabolic activation of IQ via N-hydroxylation and the formation of DNA adducts. In monkeys undergoing carcinogen bioassay with IQ, N-hydroxylation was confirmed by the presence of the N-hydroxy-N-glucuronide conjugate of IQ in urine. The N-hydroxylation of IQ appears to be carried out largely by hepatic CYP3A4 and/or CYP2C9/10, and not by CYP1A2, an isoform not expressed in liver of this species. Notably MeIQx is poorly activated in cynomolgus monkeys and lacks the potency of IQ to induce hepatocellular carcinoma after a 5-year dosing period. The poor activation of MeIQx appears to be due to the lack of constitutive expression of CYP1A2 and an inability of other cytochromes P450, such as CYP3A4 and CYP2C9/10, to N-hydroxylate the quinoxalines. MeIQx is detoxified in monkeys largely by conjugation with glucuronide at the N-1 position, Although the carcinogenicity of PhIP is not yet known, the metabolic data suggest that PhIP will be carcinogenic in this species. PhIP is metabolically activated in vivo in monkeys by N-hydroxylation, as discerned by the presence of the N-hydroxy-N-glucuronide conjugate in urine, bile, and plasma. PhIP also produces DNA adducts that are widely distributed in tissues. The results from these studies support the importance of N-hydroxylation in the carcinogenicity of HCAs in nonhuman primates and by analogy, the importance of this metabolic activation step in the possible carcinogenicity of dietary HCAs in humans. C1 NESTEC LTD, NESTLE RES CTR, CH-1000 LAUSANNE, SWITZERLAND. LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA USA. MED COLL OHIO, DEPT PATHOL, TOLEDO, OH 43699 USA. NATL CANC CTR, RES INST, TOKYO 104, JAPAN. NCI, CELLULAR CARCINOGENESIS & TUMOR PROMOT LAB, BETHESDA, MD 20892 USA. NATL SOFT DRINK ASSOC, WASHINGTON, DC USA. RP Snyderwine, EG (reprint author), NCI, EXPT CARCINOGENESIS LAB, BLDG 37, ROOM 3C28, BETHESDA, MD 20892 USA. FU NCI NIH HHS [N01-CP-51013] NR 28 TC 41 Z9 46 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 EI 1873-135X J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAY 12 PY 1997 VL 376 IS 1-2 BP 203 EP 210 DI 10.1016/S0027-5107(97)00044-4 PG 8 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XE489 UT WOS:A1997XE48900028 PM 9202757 ER PT J AU Turteltaub, KW Mauthe, RJ Dingley, KH Vogel, JS Frantz, CE Garner, RC Shen, N AF Turteltaub, KW Mauthe, RJ Dingley, KH Vogel, JS Frantz, CE Garner, RC Shen, N TI MeIQx-DNA adduct formation in rodent and human tissues at low doses SO MUTATION RESEARCH-FUNDAMENTAL AND MOLECULAR MECHANISMS OF MUTAGENESIS LA English DT Article; Proceedings Paper CT 6th International Conference on Carcinogenic and Mutagenic N-Substituted Aryl Compounds CY NOV 04-08, 1995 CL MONTEREY, CA SP Flavor & Extract Manufacturers Assoc US, Int Flavors & Fragrances Inc, Lawrence Livermore Natl Lab, Biol & Biotechnol Res Program, US FDA, Natl Ctr Toxicol Res, NCI, NIEHS, Nestle S A, Toronto Res Chem Inc ID ACCELERATOR MASS-SPECTROMETRY; HETEROCYCLIC AMINE CARCINOGENS; FOOD-BORNE CARCINOGEN; METABOLIC-ACTIVATION; COVALENT BINDING; RISK ASSESSMENT; CANCER RISK; RAT-LIVER; EXPOSURE; 2-AMINO-3,8-DIMETHYLIMIDAZO<4,5-F>QUINOXALINE AB Heterocyclic amines, such as 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), are mutagenic/carcinogenic compounds formed during the cooking of protein-rich foods. Human exposure to MeIQx has been estimated to range from ng/person/day to a few mu g/person/day. In contrast, animal studies have been conducted at doses in excess of 10 mg/kg/day. In order to determine the relevance of high-dose animal data for human exposure, the dose-response curves for [C-14]-MeIQx have been determined in rodents at low doses under both single-dose and chronic dosing regimens using the high sensitivity of accelerator mass spectrometry (AMS). To make a direct species comparison, rodent and human colonic MeIQx-DNA adduct levels have been compared following oral administration of [C-14]-MeIQx. The results of these studies show: (1) total MeIQx levels are highest in the liver >> kidney > pancreas > intestine > blood; (2) MeIQx levels in the liver plateau after 7 days of chronic feeding; (3) hepatic MeIQx-DNA adducts begin to plateau after 2-4 weeks and reach steady-state levels between 4 and 12 weeks on chronic exposures; (4) hepatic DNA adducts generally increase as a linear function of administered dose for a single-dose exposure and as a power function for chronic feeding over a dose range spanning 4 orders of magnitude; (5) human colon DNA adduct levels are similar to 10 times greater than in rodents at the same dose and time point following exposure; and(6) greater than or equal to 90% of the MeIQx-DNA adduct in both rodent and human colon appears to be the dG-C8-MeIQx adduct. These studies show that MeIQx is readily available to the tissues for both humans and rodents and that adduct levels are generally linear with administered dose except at high chronic doses where adduct levels begin to plateau slightly. This plateau indicates that linear extrapolation from high-dose studies probably underestimates the amount of DNA damage present in the tissues following low dose. Further, if adducts represent the biologically effective dose, these data show that human colon may be as sensitive to the genotoxic effects of MeIQx as rat liver. The significance of these endpoints to tumor response remains to be determined. C1 UNIV YORK,JACK BIRCH UNIT ENVIRONM CARCINOGENESIS,DEPT BIOL,YORK YO1 5DD,N YORKSHIRE,ENGLAND. UNIV CALIF RIVERSIDE,ENVIRONM GRAD TOXICOL PROGRAM,RIVERSIDE,CA 92521. RP Turteltaub, KW (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. FU NCI NIH HHS [CA5861] NR 42 TC 61 Z9 61 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0027-5107 J9 MUTAT RES-FUND MOL M JI Mutat. Res.-Fundam. Mol. Mech. Mutagen. PD MAY 12 PY 1997 VL 376 IS 1-2 BP 243 EP 252 DI 10.1016/S0027-5107(97)00049-3 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology SC Biotechnology & Applied Microbiology; Genetics & Heredity; Toxicology GA XE489 UT WOS:A1997XE48900032 PM 9202761 ER PT J AU Skalski, J Mizutori, S Nazarewicz, W AF Skalski, J Mizutori, S Nazarewicz, W TI Equilibrium shapes and high-spin properties of the neutron-rich A approximate to 100 nuclei SO NUCLEAR PHYSICS A LA English DT Review ID GROUND-STATE PROPERTIES; MEAN-FIELD THEORY; RU ISOTOPES; ROTATING NUCLEI; TRIAXIAL SHAPE; MASS FORMULA; MO ISOTOPES; DEFORMATION; REGION; ZR AB Shapes and high-spin properties of nuclei from the neutron-rich (N > 56) zirconium region are calculated using the Nilsson-Strutinsky method with the cranked Woods-Saxon average potential and a monopole pairing residual interaction, The shape coexistence effects and the competition between rotationally aligned 1h(11/2) neutron and 1g(9/2) proton bands is discussed. Predictions are made for the low-lying superdeformed bands in this mass region, characterized by the intruder states originating from the N = 5 and 6 oscillator shells. (C) 1997 Published by Elsevier Science B.V. C1 SOLTAN INST NUCL STUDIES, PL-00681 WARSAW, POLAND. OAK RIDGE NATL LAB, DIV PHYS, OAK RIDGE, TN 37831 USA. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. UNIV WARSAW, INST THEORET PHYS, PL-00681 WARSAW, POLAND. RP OAK RIDGE NATL LAB, JOINT INST HEAVY ION RES, POB 2008, OAK RIDGE, TN 37831 USA. NR 119 TC 153 Z9 156 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 12 PY 1997 VL 617 IS 3 BP 282 EP 315 DI 10.1016/S0375-9474(97)00125-5 PG 34 WC Physics, Nuclear SC Physics GA WY131 UT WOS:A1997WY13100002 ER PT J AU Gunion, JF Vogt, R AF Gunion, JF Vogt, R TI Determining the existence and nature of the quark-gluon plasma by Upsilon suppression at the LHC SO NUCLEAR PHYSICS B LA English DT Article DE heavy-ion collisions; quark-gluon plasma ID HEAVY-ION COLLISIONS; J-PSI-SUPPRESSION; NUCLEUS-NUCLEUS COLLISIONS; DRELL-YAN PAIR; TO-BACK JETS; PARTON DISTRIBUTIONS; TRANSVERSE-MOMENTUM; HADRONIC COLLISIONS; FINITE TEMPERATURE; J/PSI-SUPPRESSION AB Minijet production in root s = 5.5 TeV Pb + Pb collisions at the LHC is expected to produce a gluon-dominated plasma with large initial temperatures and energy densities. We discuss the implications of the high initial temperatures on the screening mass and on the relative suppression of members of the Upsilon family. We demonstrate that p(T) dependence of the Upsilon'/Upsilon ratio is only expected if a quark-gluon plasma with significant energy density is present, and that the precise dependence of this ratio will strongly constrain the QGP models. We also propose that the p(T) spectra of the Upsilon resonances themselves will provide valuable information by comparing these spectra to that of the Z boson, which should not be influenced by plasma production. (C) 1997 Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. RP Gunion, JF (reprint author), UNIV CALIF DAVIS,DEPT PHYS,DAVIS INST HIGH ENERGY PHYS,DAVIS,CA 95616, USA. NR 98 TC 50 Z9 50 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 J9 NUCL PHYS B JI Nucl. Phys. B PD MAY 12 PY 1997 VL 492 IS 1-2 BP 301 EP 337 PG 37 WC Physics, Particles & Fields SC Physics GA WZ677 UT WOS:A1997WZ67700013 ER PT J AU Pisarski, RD Tytgat, R AF Pisarski, RD Tytgat, R TI Scattering of soft, cool pions SO PHYSICAL REVIEW LETTERS LA English DT Article ID HARD THERMAL LOOPS; HOT GAUGE-THEORIES; QUARK-GLUON PLASMA; HIGH-TEMPERATURE; QCD; LAGRANGIANS; AMPLITUDES AB Consider the effective Lagrangian for pions in the chiral limit, computed to leading order in an expansion about zero temperature. To describe the scattering of pions with small momenta, it is necessary to include not just the usual shift in the pion decay constant, but also a new, nonlocal term, which is precisely analogous to the hard thermal loops of hot gauge theories. RP BROOKHAVEN NATL LAB, DEPT PHYS, UPTON, NY 11973 USA. NR 34 TC 18 Z9 18 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3622 EP 3625 DI 10.1103/PhysRevLett.78.3622 PG 4 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600009 ER PT J AU Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K DelSignore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Goncharov, PI Solis, JLG Gordon, H Goss, LT Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grim, G Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jiang, JZY JoffeMinor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Landsberg, G Lauer, B Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lakos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Robinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vittoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abachi, S Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alvarez, G Alves, GA Amidi, E Amos, N Anderson, EW Aronson, SH Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Bendich, J Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Bischoff, A Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Borders, J Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D CastillaValdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C CullenVidal, D Cummings, MAC Cutts, D Dahl, OI De, K DelSignore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M DiLoreto, G Draper, P Drinkard, J Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahey, S Fahland, T Fatyga, M Fatyga, MK Featherly, J Feher, S Fein, D Ferbel, T Finocchiaro, G Fisk, HE Fisyak, Y Flattum, E Forden, GE Fortner, M Frame, KC Franzini, P Fuess, S Gallas, E Galyaev, AN Gartung, P Geld, TL Genik, RJ Genser, K Gerber, CE Gibbard, B Glebov, V Glenn, S Gobbi, B Goforth, M Goldschmidt, A Gomez, B Goncharov, PI Solis, JLG Gordon, H Goss, LT Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Griffin, G Grim, G Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Guryn, W Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U HernandezMontoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jiang, JZY JoffeMinor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kerth, L Kim, CL Kim, SK Klatchko, A Klima, B Klochkov, BI Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Landsberg, G Lauer, B Lebrat, JF Leflat, A Li, H Li, J Li, YK LiDemarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lakos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R MaganaMendoza, L Mani, S Mao, HS Markeloff, R Markosky, L Marshall, T Martin, MI May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merritt, KW Miettinen, H Mincer, A deMiranda, JM Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P daMotta, H Mudan, M Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P Nesic, D Nicola, M Norman, D Oesch, L Oguri, V Oltman, E Oshima, N Owen, D Padley, P Pang, M Para, A Park, YM Partridge, R Parua, N Paterno, M Perkins, J Peters, M Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Puseljic, D Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rapidis, PA Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Robinov, P Ruchti, R Rutherfoord, J SanchezHernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, A Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stoianova, DA Stoker, D Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vittoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, Q Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Limits on anomalous WW gamma couplings from p(p)over-bar->W gamma+X events at root s=1.8 TeV SO PHYSICAL REVIEW LETTERS LA English DT Article ID WEAK-BOSON SECTOR; HADRON COLLIDERS; COLLISIONS; VERTEX AB We have measured the WW gamma gauge boson coupling parameters using -->l nu gamma+X (l=e,mu) events at root s=1.8 TeV. The data, corresponding to an integrated luminosity of 92.8 pb(-1), were collected using the D{empty set} detector at the Fermilab Tevatron Collider. The measured cross section times branching ratio for -->W gamma+X with p(T)(gamma)>10 GeV/c and R-l gamma >0.7 is 11.3(-1.5)(+1.7)+/-1.5 pb, in agreement with the standard model prediction. The 1 degree of freedom 95% confidence level limits on individual CP-conserving parameters are -0.93 -->E-t gamma+X data at root s=1.8 TeV with the D{empty set} detector at the Fermilab Tevatron Collider. This is the first study of hadronic Z(gamma) production in the neutrino decay channel. Combining this measurement with our previous results using Z-->ee and mu mu yields the most stringent 95% C.L. limits to date on anomalous couplings: /h(30)(Z)/ <0.4, /h(40)(Z)/ <0.06 (Lambda=750 GeV). C1 UNIV LOS ANDES,BOGOTA,COLOMBIA. UNIV ARIZONA,TUCSON,AZ 85721. BOSTON UNIV,BOSTON,MA 02215. BROOKHAVEN NATL LAB,UPTON,NY 11973. BROWN UNIV,PROVIDENCE,RI 02912. UNIV BUENOS AIRES,BUENOS AIRES,DF,ARGENTINA. UNIV CALIF DAVIS,DAVIS,CA 95616. UNIV CALIF IRVINE,IRVINE,CA 92697. UNIV CALIF RIVERSIDE,RIVERSIDE,CA 92521. CTR BRASILEIRO PESQUISAS FIS,LAFEX,RIO JANEIRO,BRAZIL. CTR INVEST & ESTUDIOS AVANZADOS,MEXICO CITY,DF,MEXICO. COLUMBIA UNIV,NEW YORK,NY 10027. UNIV DELHI,DELHI 110007,INDIA. FLORIDA STATE UNIV,TALLAHASSEE,FL 32306. UNIV HAWAII,HONOLULU,HI 96822. UNIV ILLINOIS,CHICAGO,IL 60607. INDIANA UNIV,BLOOMINGTON,IN 47405. IOWA STATE UNIV,AMES,IA 50011. KOREA UNIV,SEOUL 136701,SOUTH KOREA. KYUNGSUNG UNIV,PUSAN 608736,SOUTH KOREA. UNIV CALIF BERKELEY,BERKELEY,CA 94720. LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. UNIV MARYLAND,COLLEGE PK,MD 20742. UNIV MICHIGAN,ANN ARBOR,MI 48109. MICHIGAN STATE UNIV,E LANSING,MI 48824. MOSCOW MV LOMONOSOV STATE UNIV,MOSCOW,RUSSIA. UNIV NEBRASKA,LINCOLN,NE 68588. NYU,NEW YORK,NY 10003. NORTHEASTERN UNIV,BOSTON,MA 02115. NO ILLINOIS UNIV,DE KALB,IL 60115. NORTHWESTERN UNIV,EVANSTON,IL 60208. UNIV NOTRE DAME,NOTRE DAME,IN 46556. UNIV OKLAHOMA,NORMAN,OK 73019. PANJAB UNIV,CHANDIGARH 160014,INDIA. INST HIGH ENERGY PHYS,PROTVINO 142284,RUSSIA. PURDUE UNIV,W LAFAYETTE,IN 47907. UNIV ESTADUAL RIO DE JANEIRO,RIO JANEIRO,BRAZIL. UNIV ROCHESTER,ROCHESTER,NY 14627. RICE UNIV,HOUSTON,TX 77005. CTR ETUD SACLAY,CEA,DEPT ASTROPHYS PHYS PARTICULES PHYS NUCL & INSTRU,SERV PHYS PARTICULES,F-91191 GIF SUR YVETTE,FRANCE. SEOUL NATL UNIV,SEOUL,SOUTH KOREA. SUNY STONY BROOK,STONY BROOK,NY 11794. TATA INST FUNDAMENTAL RES,MUMBAI 400005,INDIA. UNIV TEXAS,ARLINGTON,TX 76019. TEXAS A&M UNIV,COLLEGE STN,TX 77843. RP Abachi, S (reprint author), FERMILAB NATL ACCELERATOR LAB,POB 500,BATAVIA,IL 60510, USA. RI Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Dudko, Lev/D-7127-2012; Leflat, Alexander/D-7284-2012; Merkin, Mikhail/D-6809-2012; Klyukhin, Vyacheslav/D-6850-2012; De, Kaushik/N-1953-2013; Oguri, Vitor/B-5403-2013; Alves, Gilvan/C-4007-2013; Sznajder, Andre/L-1621-2016 OI Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Aihara, Hiroaki/0000-0002-1907-5964; Dudko, Lev/0000-0002-4462-3192; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; Sznajder, Andre/0000-0001-6998-1108 NR 18 TC 47 Z9 47 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3640 EP 3645 DI 10.1103/PhysRevLett.78.3640 PG 6 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600013 ER PT J AU Stotzer, RW Burger, T Barnes, PD Bassalleck, B Berdoz, AR Burger, M Chrien, RE Davis, CA Diebold, GE Enyo, H Fischer, H Franklin, GB Franz, J Gan, L Gill, DR Iijima, T Imai, K Koran, P Landry, M Lee, L Lowe, J Magahiz, R Masaike, A McCrady, R Merrill, F Meyer, CA Nelson, JM Okada, K Page, SA Pile, PH Quinn, BP Ramsay, WD Rossle, E Rusek, A Sawafta, R Schmitt, H Schumacher, RA Stearns, RL Sukaton, IR Sutter, R Szymanski, JJ Takeutchi, F vanOers, WTH Wolfe, DM Yamamoto, K Yosoi, M Zeps, VJ Zybert, R AF Stotzer, RW Burger, T Barnes, PD Bassalleck, B Berdoz, AR Burger, M Chrien, RE Davis, CA Diebold, GE Enyo, H Fischer, H Franklin, GB Franz, J Gan, L Gill, DR Iijima, T Imai, K Koran, P Landry, M Lee, L Lowe, J Magahiz, R Masaike, A McCrady, R Merrill, F Meyer, CA Nelson, JM Okada, K Page, SA Pile, PH Quinn, BP Ramsay, WD Rossle, E Rusek, A Sawafta, R Schmitt, H Schumacher, RA Stearns, RL Sukaton, IR Sutter, R Szymanski, JJ Takeutchi, F vanOers, WTH Wolfe, DM Yamamoto, K Yosoi, M Zeps, VJ Zybert, R TI Search for the H-dibaryon in He-3(K-,K+)Hn SO PHYSICAL REVIEW LETTERS LA English DT Article ID K-,K+ REACTION AB A high-sensitivity search for the strangeness S=-2 H dibaryon (uundss) was conducted at the Brookhaven Alternating Gradient Synchrotron (AGS) using the reaction He-3(K-, K+)Hn at PK-=1.8 GeVc. The sensitivity was independent of H lifetime and decay modes. No evidence for H production was observed. In a mass range extending from about 50 to 380 MeV/c(2) below the Lambda Lambda threshold of 2.231 GeV/c(2), the resulting upper limits on the H-production cross section are in the range of 0.058 to 0.021 mu b/sr, approximately 1 order of magnitude below a theoretical calculation. C1 UNIV BIRMINGHAM,DEPT PHYS,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. BROOKHAVEN NATL LAB,UPTON,NY 11973. CARNEGIE MELLON UNIV,DEPT PHYS,PITTSBURGH,PA 15213. UNIV FREIBURG,FAK PHYS,D-79104 FREIBURG,GERMANY. INDIANA UNIV,CYCLOTRON FACIL,BLOOMINGTON,IN 47405. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV MANITOBA,DEPT PHYS,WINNIPEG,MB R3T 2N2,CANADA. TRIUMF,VANCOUVER,BC V6T 2A3,CANADA. VASSAR COLL,DEPT PHYS & ASTRON,POUGHKEEPSIE,NY 12601. YALE UNIV,DEPT PHYS,NEW HAVEN,CT 06511. KYOTO UNIV,DEPT PHYS,SAKYO KU,KYOTO 606,JAPAN. KYOTO SANGYO UNIV,FAC SCI,KYOTO 603,JAPAN. RP Stotzer, RW (reprint author), UNIV NEW MEXICO,DEPT PHYS & ASTRON,ALBUQUERQUE,NM 87131, USA. RI Schumacher, Reinhard/K-6455-2013; Meyer, Curtis/L-3488-2014 OI Schumacher, Reinhard/0000-0002-3860-1827; Meyer, Curtis/0000-0001-7599-3973 NR 21 TC 55 Z9 55 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3646 EP 3649 DI 10.1103/PhysRevLett.78.3646 PG 4 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600014 ER PT J AU Carpenter, MP Janssens, RVF Amro, H Blumenthal, DJ Brown, LT Seweryniak, D Woods, PJ Ackermann, D Ahmad, I Davids, C Fischer, SM Hackman, G Hamilton, JH Khoo, TL Lauritsen, T Lister, CJ Nisius, D Ramayya, AV Reviol, W Schwartz, J Simpson, J Wauters, J AF Carpenter, MP Janssens, RVF Amro, H Blumenthal, DJ Brown, LT Seweryniak, D Woods, PJ Ackermann, D Ahmad, I Davids, C Fischer, SM Hackman, G Hamilton, JH Khoo, TL Lauritsen, T Lister, CJ Nisius, D Ramayya, AV Reviol, W Schwartz, J Simpson, J Wauters, J TI Excited states in Hg-176,Hg-178 and shape coexistence in very neutron-deficient Hg isotopes SO PHYSICAL REVIEW LETTERS LA English DT Article ID ALPHA-DECAY; NUCLEI; MERCURY; HG-180 AB Excited states have been observed for the first time in the neutron-deficient Hg-176,Hg-178 nuclei using the recoil-decay tagging (RDT) technique in which prompt gamma rays are associated with a particular isotope through a correlation with the characteristic ground state alpha decay. Below N=102, the excitation energy of a rotational band built on a prolate shape (beta(2) similar to 0.25) increases with decreasing mass to the point where there is no longer any evidence for its presence at low spin in Hg-176. Th, data are in qualitative agreement with recent mean field calculations. C1 N CAROLINA STATE UNIV,RALEIGH,NC 27695. TRIANGLE UNIV NUCL LAB,DURHAM,NC 27708. VANDERBILT UNIV,DEPT PHYS,NASHVILLE,TN 37235. UNIV EDINBURGH,DEPT PHYS,EDINBURGH EH9 3JZ,MIDLOTHIAN,SCOTLAND. UNIV TENNESSEE,DEPT PHYS,KNOXVILLE,TN 37996. YALE UNIV,WRIGHT NUCL STRUCT LAB,NEW HAVEN,CT 06511. SERC,DARESBURY LAB,CCLRC,WARRINGTON WA4 4AD,CHESHIRE,ENGLAND. RP Carpenter, MP (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Carpenter, Michael/E-4287-2015 OI Carpenter, Michael/0000-0002-3237-5734 NR 24 TC 57 Z9 57 U1 1 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3650 EP 3653 DI 10.1103/PhysRevLett.78.3650 PG 4 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600015 ER PT J AU Pilgrim, WC Ross, M Yang, LH Hensel, F AF Pilgrim, WC Ross, M Yang, LH Hensel, F TI Monatomic-molecular transition in expanded rubidium SO PHYSICAL REVIEW LETTERS LA English DT Article ID LIQUID RUBIDIUM; MAGNETIC-SUSCEPTIBILITY; DYNAMIC STRUCTURE; CESIUM; METALS; NITROGEN; CURVES; VAPOR AB S(Q,omega) for liquid rubidium measured along the liquid vapor coexistence line exhibits monatomic behavior from normal density down to twice the critical density. At this density we observe excitations characteristic of a harmonic oscillator. We interpret this as evidence for the passage of the fluid from a monatomic to a molecular state. First principle total energy calculations for lattices of ribidium at 0 K predict that expansion favors spin pairing and leads to a lattice of dimers with an increase in vibron energy with decreasing density. The excellent agreement of the calculated vibron energy with the experimental result provides theoretical support for the appearance of molecules. C1 UNIV MARBURG,CTR MAT SCI,D-35032 MARBURG,GERMANY. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RP Pilgrim, WC (reprint author), UNIV MARBURG,INST PHYS CHEM,D-35032 MARBURG,GERMANY. NR 26 TC 43 Z9 44 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3685 EP 3688 DI 10.1103/PhysRevLett.78.3685 PG 4 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600024 ER PT J AU Kondo, S Johnston, DC Swenson, CA Borsa, F Mahajan, AV Miller, LL Gu, T Goldman, AI Maple, MB Gajewski, DA Freeman, EJ Dilley, NR Dickey, RP Merrin, J Kojima, K Luke, GM Uemura, YJ Chmaissem, O Jorgensen, JD AF Kondo, S Johnston, DC Swenson, CA Borsa, F Mahajan, AV Miller, LL Gu, T Goldman, AI Maple, MB Gajewski, DA Freeman, EJ Dilley, NR Dickey, RP Merrin, J Kojima, K Luke, GM Uemura, YJ Chmaissem, O Jorgensen, JD TI LiV2O4: A heavy fermion transition metal oxide SO PHYSICAL REVIEW LETTERS LA English DT Article ID NORMAL STATE PROPERTIES; O4 SPINEL COMPOUNDS; MAGNETIC-SUSCEPTIBILITY; ELECTRONIC-STRUCTURE; LI-7 NMR; LIXZN1-XV2O4; LI1+XTI2-XO4; BEHAVIOR; LITI2O4; SYSTEM AB A crossover with decreasing temperature T from localized moment magnetism to heavy Fermi liquid behavior is reported for the metallic compound LiV2O4 with the fee normal-spinel structure. At T = 1 K, the electronic heat capacity coefficient gamma approximate to 0.42 J/mol K-2 is exceptionally large for a transition metal compound, the Wilson ratio approximate to 1.7, and the Korringa ratio approximate to 0.7. Our sample with the lowest level of paramagnetic defects showed no static magnetic order above 0.02 K. Superconductivity was not observed above 0.01 K. C1 IOWA STATE UNIV SCI & TECHNOL,DEPT PHYS & ASTRON,AMES,IA 50011. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. UNIV CALIF SAN DIEGO,INST PURE & APPL PHYS SCI,LA JOLLA,CA 92093. COLUMBIA UNIV,DEPT PHYS,NEW YORK,NY 10027. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. RP Kondo, S (reprint author), IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011, USA. RI Luke, Graeme/A-9094-2010; OI Luke, Graeme/0000-0003-4762-1173 NR 30 TC 376 Z9 377 U1 8 U2 100 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3729 EP 3732 DI 10.1103/PhysRevLett.78.3729 PG 4 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600035 ER PT J AU Graf, T Thompson, JD Hundley, MF Movshovich, R Fisk, Z Mandrus, D Fisher, RA Phillips, NE AF Graf, T Thompson, JD Hundley, MF Movshovich, R Fisk, Z Mandrus, D Fisher, RA Phillips, NE TI Comparison of CeRh2Si2 and CeRh2-xRuxSi2 near their magnetic-nonmagnetic boundaries SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMI-LIQUID BEHAVIOR; ELECTRON MATERIALS; HIGH-PRESSURE; SYSTEMS; TEMPERATURE; HYBRIDIZATION AB A zero-temperature magnetic-nonmagnetic phase boundary is accessed in CeRh2Si2 by application of pressure and in CeRh2-xRuxSi2 at ambient pressure for x approximate to 1.0. A comparison of specific heat and resistivity measurements in the two cases emphasizes the importance of disorder in producing non-Fermi-liquid-like behavior in these as well as in other Ce-based systems. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94270. UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94270. FLORIDA STATE UNIV,NATL HIGH MAGNET FIELD LAB,TALLAHASSEE,FL 32306. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Mandrus, David/H-3090-2014 NR 31 TC 102 Z9 102 U1 0 U2 10 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 12 PY 1997 VL 78 IS 19 BP 3769 EP 3772 DI 10.1103/PhysRevLett.78.3769 PG 4 WC Physics, Multidisciplinary SC Physics GA WY166 UT WOS:A1997WY16600045 ER PT J AU Nieto, MM AF Nieto, MM TI Displaced and squeezed number states SO PHYSICS LETTERS A LA English DT Article ID GENERALIZED COHERENT STATES; PRINCIPLE AB From a background of displaced (coherent) and squeezed states, previous (often forgotten) work on displaced and squeezed number states is reviewed. We derive the most general of such states. The time-dependent expectation values, uncertainties, wave-functions. and probability densities are obtained. We comment on the possibility of experimentally observing these states. (C) 1997 Published by Elsevier Science B.V. C1 UNIV ULM,ABT QUANTENPHYS,D-89069 ULM,GERMANY. RP Nieto, MM (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 41 TC 68 Z9 70 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD MAY 12 PY 1997 VL 229 IS 3 BP 135 EP 143 DI 10.1016/S0375-9601(97)00183-7 PG 9 WC Physics, Multidisciplinary SC Physics GA WX021 UT WOS:A1997WX02100001 ER PT J AU Zimmermann, F Raubenheimer, T AF Zimmermann, F Raubenheimer, T TI Longitudinal space charge in final-focus systems for linear colliders SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article AB In the final-focus system of a linear collider, the effect of longitudinal space charge can be significant. A diverging or converging ultra-relativistic beam experiences a longitudinal space-charge force which is independent of the beam energy. This force, though weak and often neglected, causes an energy variation across the bunch which depends on the beam size, beam-pipe radius and bunch population and this may affect the chromatic correction of a beam line. Because of the inherent large chromaticity of a typical final-focus system, a very small energy variation, induced in the final focus, can lead to an intolerable increase of the spot size at the interaction point. The space-charge force, thus, gives rise to a limit on bunch intensity beyond which the resulting spot-size increase will degrade the collider performance. In this paper, we evaluate the effect of the longitudinal space charge and derive intensity limits for the three existing or proposed anal foci. C1 STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. NR 11 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD MAY 11 PY 1997 VL 390 IS 3 BP 279 EP 285 DI 10.1016/S0168-9002(97)00406-3 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA XJ497 UT WOS:A1997XJ49700001 ER PT J AU Holzapfel, WL Arnaud, M Ade, PAR Church, SE Fischer, ML Mauskopf, PD Rephaeli, Y Wilbanks, TM Lange, AE AF Holzapfel, WL Arnaud, M Ade, PAR Church, SE Fischer, ML Mauskopf, PD Rephaeli, Y Wilbanks, TM Lange, AE TI Measurement of the Hubble constant from X-ray and 2.1 millimeter observations of Abell 2163 SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; cosmology, observations; distance scale galaxies, clusters, individual (Abell 2163); X-rays, galaxies ID SPHERICAL CLOUDS; COMA CLUSTER; HOT GAS; GALAXIES; COMPTONIZATION; EVAPORATION; TEMPERATURE; SPECTRA; COBE AB We report 2.1 mm observations of the Sunyaev-Zeldovich (S-Z) effect; these observations confirm our previous detection of a decrement in the cosmic microwave background intensity toward the cluster Abell 2163. The S-Z data are analyzed using the relativistically correct expression for the Comptonization. We begin by assuming the intracluster (IC) gas to be isothermal at the emission-weighted average temperature determined by a combined analysis of the ASCA and Ginga X-ray satellite observations. The results of ROSAT/PSPC observations are used to determine an isothermal model for the S-Z surface brightness. Fitting to this model, we determine the peak Comptonization to be y(0) = 3.73(-0.61)(+0.47) x 10(-4). The uncertainty includes contributions due to statistical uncertainty in the detection, instrumental baseline, calibration, and density model. Combining the X-ray and S-Z measurements, we determine the Hubble constant to be H-0(q(0) = 1/2) = 60(-23)(+40) km s(-1) Mpc(-1), where the uncertainty is dominated by the systematic difference in the ASCA- and Ginga-determined IC gas temperatures. ASCA observations suggest the presence of a significant thermal gradient in the IC gas. We determine H-0 as a function of the assumed IC gas thermal structure. Using the ASCA-determined thermal structure and keeping the emission-weighted average temperature the same as in the isothermal case, we find H-0(q(0) = 1/2) = 78(-28)(+54) km s(-1) Mpc(-1). Including additional uncertainties due to cluster asphericity, peculiar velocity, IC gas clumping, and astrophysical confusion, we find H-0(q(0) = 1/2) = 78(-40)(+60) km s(-1) Mpc(-1). C1 CTR ETUD SACLAY,SERV ASTROPHYS,DAPNIA,DSM,F-91191 GIF SUR YVETTE,FRANCE. UNIV LONDON QUEEN MARY & WESTFIELD COLL,DEPT PHYS,LONDON E1 4NS,ENGLAND. CALTECH,DEPT PHYS MATH & ASTRON,PASADENA,CA 91125. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720. UNIV CALIF BERKELEY,CTR PARTICLE ASTROPHYS,BERKELEY,CA 94720. ARADIGM CORP,HAYWARD,CA 94545. RP Holzapfel, WL (reprint author), UNIV CHICAGO,ENRICO FERMI INST,5640 S ELLIS AVE,CHICAGO,IL 60637, USA. RI Holzapfel, William/I-4836-2015 NR 46 TC 77 Z9 78 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 MAY 10 PY 1997 VL 480 IS 2 BP 449 EP 465 DI 10.1086/303979 PN 1 PG 17 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WW855 UT WOS:A1997WW85500001 ER PT J AU Gundes, AN AF Gundes, AN TI Stabilizing controllers for interconnected systems SO INTERNATIONAL JOURNAL OF CONTROL LA English DT Article ID COPRIME AB Coprime factorizations of cascade, parallel and feedback interconnections of two given subsystems are derived and used to characterize all stabilizing controllers. The coprime factorizations are presented in the general algebraic setting and applied to state-space representations. It is shown that the conditions for existence of stabilizing controllers using a transfer-function approach are equivalent to the conditions of stabilizability and detectability of the corresponding state-space representations for each of the three types of interconnections. RP Gundes, AN (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT ELECT & COMP ENGN,DAVIS,CA 95616, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0020-7179 J9 INT J CONTROL JI Int. J. Control PD MAY 10 PY 1997 VL 67 IS 1 BP 45 EP 68 DI 10.1080/002071797224351 PG 24 WC Automation & Control Systems SC Automation & Control Systems GA WY535 UT WOS:A1997WY53500004 ER PT J AU Irvine, JM Evers, TK Smyre, JL Huff, D King, AL Stahl, G Odenweller, J AF Irvine, JM Evers, TK Smyre, JL Huff, D King, AL Stahl, G Odenweller, J TI The detection and mapping of buried waste SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB Determining the exact location of buried waste trenches is an important step in the characterization and remediation of certain hazardous waste sites. Remotely sensed data offers a rich source of information for accomplishing this task. This paper presents an investigation of buried waste trenches located at Oak Ridge National Laboratory (ORNL) using thermal remote sensing. A comparison of historical aerial photography and recently collected thermal imagery reveals a thermal signature which coincides with the precise locations of buried waste trenches. Statistical analysis of extensive ground measurements shows a clear thermal difference between the trench and control areas, with the trenches exhibiting cooler temperatures and greater soil moisture. By incorporating the imagery-derived information into site remediation plans, ORNL realized a cost avoidance of more than U.S. $5 000 000. Similar benefits can be anticipated at other DOE waste sites. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. ENVIRONM RES INST MICHIGAN,ANN ARBOR,MI 48113. RP Irvine, JM (reprint author), ENVIRONM RES INST MICHIGAN,1101 WILSON BLVD,SUITE 100,ARLINGTON,VA 22209, USA. NR 9 TC 7 Z9 7 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD MAY 10 PY 1997 VL 18 IS 7 BP 1583 EP 1595 DI 10.1080/014311697218296 PG 13 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA WV632 UT WOS:A1997WV63200011 ER PT J AU Lay, T Garnero, EJ Young, CJ Gaherty, JB AF Lay, T Garnero, EJ Young, CJ Gaherty, JB TI Scale lengths of shear velocity heterogeneity at the base of the mantle from S wave differential travel times SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID BENEATH NORTHERN SIBERIA; LOWERMOST MANTLE; DISCONTINUITY BENEATH; LATERAL VARIATIONS; P-WAVES; BOUNDARY; D''; ANOMALIES; PACIFIC; PHASES AB Resolving the seismic velocity heterogeneity in the lowermost mantle is essential for understanding the chemical and dynamical processes operating in the boundary layer between the core and the mantle. Several regions of the lowermost mantle appear to have abrupt increases in shear velocity several hundred kilometers above the core-mantle boundary, at the top of the D '' layer. This structure is revealed by seismic wave energy refracted by the velocity increase, resulting in an extra arrival (Scd) in teleseismic S wavetrains at distances from 65 degrees to 95 degrees. Anomalies in differential travel times of the extra arrival relative to direct S (which turns at shallower depths in the midmantle) or ScS (which reflects from the core-mantle boundary below the velocity increase) provide probes of the velocity heterogeneity in the lowermost mantle with better vertical resolution than provided by conventional ScS-S measurements. We explore the spatial patterns in Scd-S, ScS-Scd, and ScS-S differential time residuals for paths through the lower mantle beneath Alaska, Eurasia, and India (all being regions with coherent Scd phases) to place constraints on the strength and scale lengths of shear velocity heterogeneity and/or variable topography of the lower mantle discontinuity in these regions. The observed patterns are poorly predicted by existing global tomographic models. Significant small-scale heterogeneity, with lateral length scales of 200-500 km or less, exists even within regions that display a relatively uniform D '' discontinuity structure over scale lengths of 1500-2000 km. The strongest travel time variations are associated with structure above the D '' region, in contrast to common assumptions. Rapid lateral fluctuations in ScS-Scd differential times suggest that the anomalies accumulate within a relatively thin zone, less than the overall thickness of D ''. Correlations among the differential time anomalies indicate that Scd variations, ranging over about 4 s, are more pronounced than ScS variations and that the travel time fluctuations accumulate near the top of D '' due to shear velocity heterogeneity of +/-4% within a 50 km thick region and/or discontinuity topography of +/-50 km, with scale lengths of 200-500 km. It appears that the upper portion of D '' is much more heterogeneous than the deeper region. Heterogeneity within the layer appears to be decoupled from that at the top of the layer or in the overlying mantle. C1 UNIV CALIF SANTA CRUZ, WM KECK SEISMOL LAB, SANTA CRUZ, CA 95064 USA. SANDIA NATL LABS, DEPT GEOPHYS, ALBUQUERQUE, NM 87185 USA. MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02139 USA. RP Lay, T (reprint author), UNIV CALIF SANTA CRUZ, INST TECTON, EARTH & MARINE SCI BLDG, SANTA CRUZ, CA 95064 USA. NR 57 TC 29 Z9 30 U1 0 U2 3 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 MAY 10 PY 1997 VL 102 IS B5 BP 9887 EP 9909 DI 10.1029/97JB00331 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA WY347 UT WOS:A1997WY34700003 ER PT J AU Feng, X Fryxell, GE Wang, LQ Kim, AY Liu, J Kemner, KM AF Feng, X Fryxell, GE Wang, LQ Kim, AY Liu, J Kemner, KM TI Functionalized monolayers on ordered mesoporous supports SO SCIENCE LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; MERCURY; REMOVAL AB Mesoporous silica materials containing functionalized organic monolayers have been synthesized, Solid-state nuclear magnetic resonance suggests that a cross-linked monolayer of mercaptopropylsilane was covalently bound to mesoporous silica and closely packed on the surface. The relative surface coverage of the monolayers can be systematically varied up to 76 percent. These materials are extremely efficient in removing mercury and other heavy metals from both aqueous and nonaqueous waste streams, with distribution coefficients up to 340,000. The stability of these materials and the potential to regenerate and reuse them have also been demonstrated. The surface modification scheme reported here enables rational design of the surface properties of tailored porous materials and may lead to the synthesis of more sophisticated functionalized composites for environmental and industrial applications. C1 PACIFIC NW LAB, RICHLAND, WA 99352 USA. ARGONNE NATL LAB, ARGONNE, IL 60439 USA. NR 32 TC 1323 Z9 1386 U1 26 U2 275 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 9 PY 1997 VL 276 IS 5314 BP 923 EP 926 DI 10.1126/science.276.5314.923 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WY792 UT WOS:A1997WY79200039 ER PT J AU Tang, J Thurnauer, MC Kubo, A Hara, H Kawamori, A AF Tang, J Thurnauer, MC Kubo, A Hara, H Kawamori, A TI Anomalous pulse-angle and phase dependence of Hahn's electron spin echo and multiple-quantum echoes in a photoinduced spin-correlated radical pair SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FOURIER-TRANSFORM; TRANSIENT EPR; COHERENCE; RELAXATION AB Formation of two- and three-pulse electron spin echoes and their anomalous pulse-angle and phase dependence in a photoinduced spin-correlated radical pair are examined. Analytical formulae for the unusual Hahn's spin-echo signals and the two-pulse double-quantum echo are derived in terms of the pulse angle, microwave phase, and the time intervals between the laser pulse and the microwave pulses. Such anomalies are shown to be present in both cases of singlet and tripler precursors. Phase dependence and formation of the three-pulse stimulated echo and multiple-quantum echoes are also examined. (C) 1997 American Institute of Physics. C1 KYOTO UNIV,DEPT CHEM,SAKYO KU,KYOTO 606,JAPAN. KWANSEI GAKUIN UNIV,FAC SCI,NISHINOMIYA,HYOGO 662,JAPAN. RP Tang, J (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. RI Tang, Jau/D-8382-2012 OI Tang, Jau/0000-0003-2078-1513 NR 28 TC 14 Z9 14 U1 2 U2 5 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 MAY 8 PY 1997 VL 106 IS 18 BP 7471 EP 7478 DI 10.1063/1.473752 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WX289 UT WOS:A1997WX28900001 ER PT J AU Ahmed, M Blunt, D Chen, D Suits, AG AF Ahmed, M Blunt, D Chen, D Suits, AG TI UV photodissociation of oxalyl chloride yields four fragments from one photon absorption SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MULTIPHOTON IONIZATION; TRIPLE DISSOCIATION; MOLECULAR-BEAM; ALPHA-BOND; 193 NM; STATE; CONFORMERS; EXCITATION; DYNAMICS; GLYOXAL AB The photodissociation of oxalyl chloride, (ClCO)(2), has been studied near 235 nm using the photofragment imaging technique. Observed products include both ground state Cl (P-2(3/2)) and spin-orbit excited Cl*(P-2(1/2)) chlorine atoms and ground electronic state CO molecules. The rotational distribution obtained for the CO v=0 product is peaked at about J=30 and extends beyond J=50. Photofragment images were recorded for both chlorine atom fine structure components as well as many rotational levels of the CO v=0,yielding state-resolved angular and translational energy distributions. The recoil speed distribution for the Cl* exhibits a dominant fast component, with a translational energy distribution peaking at about 48 kJ/mol. The ground state chlorine atom showed two components in its speed distribution, with the slow component dominant. The corresponding translational energy distribution peaked at 10 kJ/mol but extended to 80 kJ/mol. The total average translational energy release into the Cl product is 34 kJ/mol. Similarly, the low rotational levels of the CO showed only a slow component, the intermediate rotational levels showed a bimodal speed distribution, and the highest rotational levels showed only the fast component. The fast components of both chlorine atom product and the higher rotational levels of the CO show an anisotropic angular distribution, while all slow fragments show a nearly isotropic angular distribution. These observations suggest a novel dissociation mechanism in which the first step is an impulsive three-body dissociation yielding predominantly Cl*, rotationally excited CO and chloroformyl radical ClCO, with only modest momentum transfer to the latter species. Most of the remaining ClCO undergoes subsequent dissociation yielding low rotational levels of CO and little translational energy release. (C) 1997 American Institute of Physics. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,DIV CHEM SCI,BERKELEY,CA 94720. RI Ahmed, Musahid/A-8733-2009 NR 39 TC 65 Z9 66 U1 0 U2 15 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 MAY 8 PY 1997 VL 106 IS 18 BP 7617 EP 7624 DI 10.1063/1.473764 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WX289 UT WOS:A1997WX28900015 ER PT J AU Althorpe, SC Kouri, DJ Hoffman, DK AF Althorpe, SC Kouri, DJ Hoffman, DK TI A Chebyshev method for calculating state-to-state reaction probabilities from the time-independent wavepacket reactant-product decoupling equations SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; DEPENDENT SCHRODINGER-EQUATION; ABSORBING BOUNDARY-CONDITIONS; POTENTIAL-ENERGY SURFACE; SCATTERING; DYNAMICS; ACCURATE; SYSTEM; H-3 AB Recently, Peng and Zhang have introduced the reactant-product decoupling (RPD) equations. These are an exact formulation of quantum mechanical reactive-scattering, whereby the Schrodinger equation is partitioned into a set of uncoupled equations, each of which describes the dynamics in one arrangement of the reaction. In this paper we derive an efficient method for solving the RPD equations which is based on the Chebyshev propagator. The derivation makes use of the recently derived time-independent wavepacket version of the RPD equations. We test the method by applying it to the collinear H+H-2 reaction. (C) 1997 American Institute of Physics. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV SCI & TECHNOL,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV SCI & TECHNOL,AMES LAB,AMES,IA 50011. RP Althorpe, SC (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. NR 35 TC 31 Z9 31 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 8 PY 1997 VL 106 IS 18 BP 7629 EP 7636 DI 10.1063/1.473766 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WX289 UT WOS:A1997WX28900017 ER PT J AU Luchow, A Anderson, JB Feller, D AF Luchow, A Anderson, JB Feller, D TI Improved estimates of the total correlation energy in the ground state of the water molecule SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CONFIGURATION-INTERACTION CALCULATIONS; QUANTUM MONTE-CARLO; GAUSSIAN-BASIS SETS; HARTREE-FOCK LIMIT; WAVE-FUNCTIONS; SYSTEMATIC SEQUENCES; BENCHMARK CALCULATIONS; DIATOMIC HYDRIDES; DIMER; BORON AB Two new calculations of the electronic energy of the ground state of the water molecule yield energies lower than those of any previously reported variational calculations. A fixed-node quantum Monte Carlo calculation gives -76.420(1) hartrees and an analytic variational calculation gives -76.4274 hartrees. These values lie only 17 and 11 mhartrees, respectively, above the ''experimental'' value. (C) 1997 American Institute of Physics. C1 PACIFIC NW LAB, ENVIRONM MOL SCI LAB, RICHLAND, WA 99352 USA. RP Luchow, A (reprint author), PENN STATE UNIV, DEPT CHEM, UNIVERSITY PK, PA 16802 USA. NR 28 TC 30 Z9 30 U1 0 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 MAY 8 PY 1997 VL 106 IS 18 BP 7706 EP 7708 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WX289 UT WOS:A1997WX28900024 ER PT J AU Cybulski, SM Kendall, RA Chalasinski, G Severson, MW Szczesniak, MM AF Cybulski, SM Kendall, RA Chalasinski, G Severson, MW Szczesniak, MM TI Ab initio study of the O-2(X (3)Sigma(g)(-))+Ar(S-1) van der Waals interaction SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID FINE-STRUCTURE SPECTRUM; POTENTIAL-ENERGY SURFACES; DER-WAALS COMPLEXES; PERTURBATION-THEORY; RANDOM-WALK; MOLECULAR INTERACTIONS; VANDERWAALS MOLECULES; INTERMOLECULAR FORCES; ABINITIO CALCULATIONS; QUANTUM-CHEMISTRY AB A potential energy surface for the Ar(S-1)+O-2(X (3) Sigma(g)(-)) interaction is calculated using the supermolecular unrestricted Moller-Plesset (UMP) perturbation theory and analyzed via the perturbation theory of intermolecular forces. The global minimum occurs for the T-shaped geometry, around 6.7 a(0). Our UMP4 estimate of the well depth of the global minimum is D-e = 117 cm(-1) and the related ground state dissociation energy obtained by diffusion Monte Carlo calculations is 88 cm(-1). These values are expected to be accurate to within a few percent. The potential energy surface also reveals a local minimum for the collinear geometry at ca similar to 7.6 a(0). The well depth for the secondary minimum at the UMP4 level is estimated at D-e = 104 cm(-1). The minima are separated by a barrier of 23 cm(-1). The global minimum is determined by the minimum in the exchange repulsion in the direction perpendicular to the O-O bond. The secondary, linear minimum is enhanced by a slight flattening of the electron density near the ends of the interoxygen axis. (C) 1997 American Institute of Physics. C1 MIAMI UNIV,DEPT CHEM,OXFORD,OH 45056. PACIFIC NW NATL LAB,ENVIRONM MOL SCI LAB,HIGH PERFORMANCE COMPUTAT CHEM GRP,RICHLAND,WA 99352. UNIV WARSAW,DEPT CHEM,PL-02093 WARSAW,POLAND. OAKLAND UNIV,DEPT CHEM,ROCHESTER,MI 48309. NR 48 TC 23 Z9 23 U1 2 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD MAY 8 PY 1997 VL 106 IS 18 BP 7731 EP 7737 DI 10.1063/1.473798 PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WX289 UT WOS:A1997WX28900028 ER PT J AU Lio, A Charych, DH Salmeron, M AF Lio, A Charych, DH Salmeron, M TI Comparative atomic force microscopy study of the chain length dependence of frictional properties of alkanethiols on gold and alkylsilanes on mica SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID ENERGY HELIUM DIFFRACTION; SELF-ASSEMBLED MONOLAYERS; ALKYLSILOXANE MONOLAYERS; ORGANOSULFUR COMPOUNDS; SUPERLATTICE STRUCTURE; INFRARED-SPECTROSCOPY; AU(111); SURFACE; FILMS; SILICON AB A comparative study of the frictional properties of alkanethiols and alkylsilanes as a function of chain length is presented. The monolayers were produced by self-assembly on Au(lll) and mica, respectively. The same tip was used for all the experiments, and freshly cleaved mica was used as a reference. For both types of films, the frictional forces depend strongly on the number of carbon atoms in the alkane chain (CH3-(CH2)(n-1)-R). Thiols and silanes give rise to similar frictional force for the same It when n > 11, while for n < 11 the behavior is markedly different; the silanes exhibit higher friction, larger than that for the thiols by a factor of similar to 3 for n = 6. The increase in friction is attributed to the increased disorder that occurs when going from a thiol to a silane anchor or when decreasing n. It is proposed that disorder favors the increase of the number and type of low-energy modes (kinks, bending, distortions) that are available for excitation and energy dissipation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV GLASGOW,DEPT ELECT,GLASGOW G12 8QQ,LANARK,SCOTLAND. NR 42 TC 240 Z9 241 U1 1 U2 29 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 MAY 8 PY 1997 VL 101 IS 19 BP 3800 EP 3805 DI 10.1021/jp963918e PG 6 WC Chemistry, Physical SC Chemistry GA WY392 UT WOS:A1997WY39200022 ER PT J AU Slusher, JT Cummings, PT AF Slusher, JT Cummings, PT TI Molecular simulation study of tetraalkylammonium halides .1. Solvation structure and hydrogen bonding in aqueous solutions SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID HYDROPHOBIC HYDRATION; TETRAMETHYLAMMONIUM CHLORIDE; MONTE-CARLO; WATER-STRUCTURE; APOLAR SOLUTES; DYNAMICS; IONS; EQUILIBRIUM; METHANE; SYSTEMS AB The hydration structure in aqueous solutions of three tetraalkylammonium halides (TAAX), tetramethylammonium chloride (TMACl), tetrapropylammonium bromide (TPABr), and tetrabutylammonium bromide (TBABr) at concentrations of 2.2, 1.4, and 1.0 in, respectively, is studied via molecular dynamics (MD) simulation at ambient conditions. The results are compared directly with neutron diffraction with isotopic substitution (NDIS) experimental results for the same systems. In agreement with the NDIS results, we find evidence of a small enhancement of water structure around the apolar solutes, based on water H-H radial distribution functions. Decomposition of the water-water O-H radial distribution function into hydrogen-bonded and non-hydrogen-bonded components, using the geometric criterion for hydrogen bonding of Mezei and Beveridge (1981), allowed us to calculate the hydrogen-bonded (HE) contribution to the total O-H radial distribution function, both in the bulk solution and in the first salvation shell of the cations. For the TPA and TEA cations, there is a small enhancement in the probability of farming hydrogen bonds between solvation shell water molecules, while the reverse is true for TMA. We find that the HE contribution to the total O-H coordination number remains approximately constant in going from pure water to the TAAX solutions. An analysis of the distributions of the parameters of the hydrogen-bonding criterion between pure water and water in the first solvation shells of the cations reveals that there is a slight tendency for the water in the first solvation shell to form more ''ideal'' hydrogen bonds compared to pure water, particularly for the the larger cations. However, the differences in the water-water structure between TPA and TEA are negligibly small. C1 OAK RIDGE NATL LAB, DIV CHEM TECHNOL, OAK RIDGE, TN 37831 USA. RP Slusher, JT (reprint author), UNIV TENNESSEE, DEPT CHEM ENGN, 419 DOUGHERTY ENGN BLDG, KNOXVILLE, TN 37996 USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 65 TC 39 Z9 39 U1 1 U2 19 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 MAY 8 PY 1997 VL 101 IS 19 BP 3818 EP 3826 DI 10.1021/jp963304+ PG 9 WC Chemistry, Physical SC Chemistry GA WY392 UT WOS:A1997WY39200025 ER PT J AU Perelson, AS Essunger, P Cao, YZ Vesanen, M Hurley, A Saksela, K Markowitz, M Ho, DD AF Perelson, AS Essunger, P Cao, YZ Vesanen, M Hurley, A Saksela, K Markowitz, M Ho, DD TI Decay characteristics of HIV-1-infected compartments during combination therapy SO NATURE LA English DT Article ID DENDRITIC CELLS; VIRUS; INFECTION; LYMPHOCYTES; HIV-1; QUANTITATION; MACROPHAGES; AIDS AB Analysis of changes in viral load after initiation of treatment with potent antiretroviral agents has provided substantial insight into the dynamics of human immunodeficiency virus type 1 (HIV-1)(1-3). The concentration of HIV-1 in plasma drops by similar to 99% in the first two weeks of treatment owing to the rapid elimination of free virus with a half-life (t(1/2)) of less than or equal to 6 hours and loss of productively infected cells with a t(1/2) of 1.6 days(3). Here we show that with combination therapy this initial decrease is followed by a slower second-phase decay of plasma viraemia. Detailed mathematical analysis shows that the loss of long-lived infected cells (t(1/2) of 1-4 weeks) is a major contributor to the second phase, whereas the activation of latently infected lymphocytes (t(1/2) of 0.5-2 weeks) is only a minor source. Based on these decay characteristics, we estimate that 2.3-3.1 years of a completely inhibitory treatment would be required to eliminate HIV-1 from these compartments. To eradicate HIV-1 completely, even longer treatment may be needed because of the possible existence of undetected viral compartments or sanctuary sites. C1 ROCKEFELLER UNIV,AARON DIAMOND AIDS RES CTR,NEW YORK,NY 10016. LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. TAMPERE UNIV,INST MED TECHNOL,FIN-33101 TAMPERE,FINLAND. NR 25 TC 1193 Z9 1216 U1 7 U2 34 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD MAY 8 PY 1997 VL 387 IS 6629 BP 188 EP 191 DI 10.1038/387188a0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WX945 UT WOS:A1997WX94500056 PM 9144290 ER PT J AU deGouvea, A Murayama, H AF deGouvea, A Murayama, H TI Excluding light gluinos from Z decays SO PHYSICS LETTERS B LA English DT Article ID TRIPLE-GLUON VERTEX; DEEP-INELASTIC SCATTERING; 4-JET EVENTS; SUPERSYMMETRIC PARTICLES; 3-GLUON VERTEX; E+E COLLIDERS; JETS; LEP; ANNIHILATION; ENERGY AB We reanalyze the constraints on light gluinos (mg less than or equal to 5 GeV/c(2)) from the hadronic Z decays into four jets. We find that the published OPAL data from the 1991 and 1992 runs exclude a light quasi-stable gluino with mass less than or similar to 1.5 GeV/c(2) at more than 90% confidence level. This limit depends little on assumptions about the gluino fragmentation and the definition of the gluino mass. The exclusion confidence level is shown as a function of the mass. A future projection is briefly discussed. We also discuss quantitatively how the distributions in the Bengtsson-Zerwas and the modified Nachtmann-Reiter angles change due to the finite bottom quark or gluino mass. The analysis is limited to the leading-order calculations. We, however, give an empirical reason to why the next-to-leading-order corrections are unlikely to change our conclusions. (C) 1997 Published by Elsevier Science B.V. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. RP deGouvea, A (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. RI Murayama, Hitoshi/A-4286-2011 NR 42 TC 8 Z9 8 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 8 PY 1997 VL 400 IS 1-2 BP 117 EP 123 DI 10.1016/S0370-2693(97)00312-2 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XA257 UT WOS:A1997XA25700019 ER PT J AU Grifols, JA Mohapatra, RN Riotto, A AF Grifols, JA Mohapatra, RN Riotto, A TI New astrophysical constraints on the mass of the superlight gravitino SO PHYSICS LETTERS B LA English DT Article ID NEUTRINO BURST; LIMITS AB In some supergravity models, the superlight gravitino is accompanied by a light weakly coupled scalar (S) and pseudoscalar particle (P). The couplings of these particles to matter (e.g. electrons and photons) is inversely proportional to the product (m(g)M(PI)) where m(g) and M-PI are respectively the gravitino mass and the Planck mass. as a result, their emission from supernovae and stars via the reaction gamma + e(-) --> S/P + e(-) for certain ranges of the gravitino mass can become the dominant energy loss mechanism in contradiction with observations thereby ruling out those mass values for the gravitino. For 10 MeV greater than or equal to mS/P greater than or equal to keV, the SN1987A observations can be used to exclude the gravitino masses in the range (10(-1.5) less than or equal to m(g) less than or equal to 30) eV, whereas if m(S/P) less than or equal to keV, constraints of stellar energy loss can exclude the range (3 x 10(-6) less than or equal to m(g) less than or equal to 50) eV for the photino mass equal to 100 GeV. We also find that if m(S/P) less than or equal to MeV, present understanding of big bang nucleosynthesis imply that m(g) greater than or equal to eV. These are the most severe bounds to date on mg in this class of models. (C) 1997 Published by Elsevier Science B.V. C1 UNIV AUTONOMA BARCELONA,IFAE,BELLATERRA 08193,SPAIN. UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742. FERMILAB NATL ACCELERATOR LAB,BATAVIA,IL 60510. RP Grifols, JA (reprint author), UNIV AUTONOMA BARCELONA,FIS TEOR GRP,BELLATERRA 08193,SPAIN. NR 28 TC 30 Z9 30 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 8 PY 1997 VL 400 IS 1-2 BP 124 EP 128 DI 10.1016/S0370-2693(97)00348-1 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XA257 UT WOS:A1997XA25700020 ER PT J AU Ellis, J Karliner, M Samuel, MA AF Ellis, J Karliner, M Samuel, MA TI A prediction for the 4-loop beta function in QCD SO PHYSICS LETTERS B LA English DT Article ID ESTIMATING PERTURBATIVE COEFFICIENTS; QUANTUM-FIELD-THEORY; MANN-LOW FUNCTION; CRITICAL EXPONENTS; PADE APPROXIMANTS; GAUGE-THEORIES; EXPANSION AB We predict that the four-loop contribution beta(3) to the QCD beta function in the <(MS)over bar> prescription is given by beta(3) similar or equal to 23600(900) - 6400(200)N-f + 350(70)N-f(2) + 1.5N(f)(3), where N-f is the number of flavours and the coefficient of N-f(3) is an exact result from large-N-f expansion. In the phenomenologically-interesting case N-f = 3, we estimate beta(3) = (7.6 +/- 0.1) x 10(3). We discuss our estimate of the errors in these QCD predictions, basing them on the demonstrated accuracy of our method in lest applications to the O(N) Phi(-1) theory, and on variations in the details of our estimation method, which goes beyond conventional Pade approximants by estimating and correcting for subasymptotic deviations from exact results. (C) 1997 Elsevier Science B.V. C1 TEL AVIV UNIV,RAYMOND & BEVERLY SACKLER FAC EXACT SCI,SCH PHYS & ASTRON,IL-69978 TEL AVIV,ISRAEL. MCGILL UNIV,DEPT PHYS,MONTREAL,PQ H3A 2T5,CANADA. STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309. OKLAHOMA STATE UNIV,DEPT PHYS,OKLAHOMA CITY,OK 74078. RP Ellis, J (reprint author), CERN,DIV THEORET PHYS,CH-1211 GENEVA 23,SWITZERLAND. RI Ellis, John/J-2222-2012 OI Ellis, John/0000-0002-7399-0813 NR 27 TC 41 Z9 41 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 MAY 8 PY 1997 VL 400 IS 1-2 BP 176 EP 181 DI 10.1016/S0370-2693(97)00342-0 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XA257 UT WOS:A1997XA25700028 ER PT J AU Melnitchouk, W Peng, JC AF Melnitchouk, W Peng, JC TI Large-x d/u ratio in W-boson production SO PHYSICS LETTERS B LA English DT Article ID GOTTFRIED SUM-RULE; INELASTIC ELECTRON-SCATTERING; DRELL-YAN PROCESS; LIGHT-QUARK SEA; PARTON DISTRIBUTIONS; SYMMETRY-BREAKING; CHARGE ASYMMETRY; STRANGE SEA; NUCLEON; DEUTERON AB Recent analysis of proton and deuteron deep-inelastic scattering date have suggested that the extracted d/u quark distribution ratio at large x may be significantly larger than previously believed, if the data are corrected for nuclear binding effects in the deuteron. We examine the sensitivity to the large-x d/u ratio of lepton asymmetries from W-boson production in and pp collisions at large rapidity, which do not suffer from nuclear contamination. (C) 1997 Published by Elsevier Science B.V. C1 LOS ALAMOS NATL LAB,DIV PHYS,LOS ALAMOS,NM 87545. RP Melnitchouk, W (reprint author), UNIV MARYLAND,DEPT PHYS,COLLEGE PK,MD 20742, USA. NR 54 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD MAY 8 PY 1997 VL 400 IS 1-2 BP 220 EP 225 DI 10.1016/S0370-2693(97)00326-2 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA XA257 UT WOS:A1997XA25700033 ER PT J AU Zang, Y Kim, J Dong, YH Wilkinson, EC Appelman, EH Que, L AF Zang, Y Kim, J Dong, YH Wilkinson, EC Appelman, EH Que, L TI Models for nonheme iron intermediates: Structural basis for tuning the spin states of Fe(TPA) complexes SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID COLI RIBONUCLEOTIDE REDUCTASE; MONOOXYGENASE CATALYTIC CYCLE; METHANE MONOOXYGENASE; ALKYLPEROXOIRON(III) INTERMEDIATE; ACTIVATED BLEOMYCIN; CRYSTAL-STRUCTURE; OXO PROTEINS; REACTIVITY; RELEVANCE; CLUSTER AB Our efforts to model the oxygen activation chemistry of nonheme iron enzymes have yielded transient intermediates with novel properties. These properties can be dramatically affected by the introduction of a 6-methyl substituent on the pendant pyridines of the tetradentate ligand TPA (TPA = tris(2-pyridylmethyl)amine). A series of Fe(TPA) complexes has thus been synthesized and characterized to provide the structural basis for these dramatic effects. The following complexes have been obtained: [Fe(L)(CH3CN)(2)](ClO4)(2) (1, L = TPA; 2, L = 6-MeTPA; 3, L = 6-Me(2)TPA; 4, L = 6-Me(3)TPA) and [Fe(L)(acac)](ClO4)(2) (5, L = TPA; 6, L = 5-Me(3)TPA; 7, L = 6-MeTPA). As indicated by H-1 NMR and/or EPR, 1, 5, and 6 wish no 6-methyl substituent are low spin, while complexes 2, 3, 4, and 7 with at least one 6-methyl substituent are all high spin, with higher redox potentials than their low-spin counterparts. The ligands with 6-methyl substituents thus favor a metal center with a larger ionic radius, i.e., Fe-II over Fe-III and high spin over low spin. Careful scrutiny of the crystal structures of 1, 4, 6, and 7 reveals that one hydrogen of the 6-methyl group is only 2.7 Angstrom away from the metal center in the high-spin complexes. Its presence thus prevents the pyridine nitrogen from forming an Fe-N bond shorter than 2.1 Angstrom as required for an iron center to adopt a low-spin configuration. This steric effect of the 6-methyl substituent serves as a simple but very useful ligand design tool to tune the electronic properties of the metastable alkylperoxoiron(III) species derived from the reactions of 1-4 with tert-butyl hydroperoxide. These intermediates serve as models for low-spin and high-spin peroxoiron(III) species in the reaction cycles of the antitumor drug bleomycin and lipoxygenase, respectively. Similar principles apply in the design of nonheme diiron(II) complexes that reversibly bind dioxygen and of high-valent bis(mu-oxo)diiron complexes that model the high-valent intermediates in the redox cycles of nonheme diiron enzymes such as methane monooxygenase and ribonucleotide reductase. C1 UNIV MINNESOTA,DEPT CHEM,MINNEAPOLIS,MN 55455. UNIV MINNESOTA,CTR MET BIOCATALYSIS,MINNEAPOLIS,MN 55455. ARGONNE NATL LAB,DIV CHEM,ARGONNE,IL 60439. NR 58 TC 226 Z9 227 U1 4 U2 37 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 MAY 7 PY 1997 VL 119 IS 18 BP 4197 EP 4205 DI 10.1021/ja9638521 PG 9 WC Chemistry, Multidisciplinary SC Chemistry GA WX989 UT WOS:A1997WX98900013 ER PT J AU Konopelski, JP Filonova, LK Olmstead, MM AF Konopelski, JP Filonova, LK Olmstead, MM TI Dipeptide surrogates containing asparagine-derived tetrahydropyrimidinones: Preparation, structure, and use in solid phase synthesis SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Letter ID ENANTIOMERICALLY PURE DIHYDROPYRIMIDINONES; BETA-AMINO ACIDS; ASYMMETRIC-SYNTHESIS; STABILIZATION; PROTECTION; PEPTIDES C1 LAWRENCE LIVERMORE NATL LAB,DEPT CHEM,DAVIS,CA 95616. RP Konopelski, JP (reprint author), UNIV CALIF SANTA CRUZ,DEPT CHEM & BIOCHEM,SANTA CRUZ,CA 95064, USA. NR 15 TC 18 Z9 19 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD MAY 7 PY 1997 VL 119 IS 18 BP 4305 EP 4306 DI 10.1021/ja9639271 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA WX989 UT WOS:A1997WX98900029 ER PT J AU Ma, Q Rosenberg, RA Kim, CY Grepstad, J Pianetta, P AF Ma, Q Rosenberg, RA Kim, CY Grepstad, J Pianetta, P TI Microscopic chemical state identification of a silicon-carbide fiber by soft x-ray photoabsorption spectroscopy SO APPLIED PHYSICS LETTERS LA English DT Article ID ABSORPTION; GRAPHITE AB Chemical states of a 140 mu m silicon carbide fiber are determined by soft x-ray photo-absorption spectroscopy, using a magnetic projection photoelectron microscope, performed on the surface obtained by fracturing. The spectrum of the carbon core of the fiber has prominent pi* and sigma* resonance peaks and is very similar to that measured on highly oriented pyrolitic graphite, indicating a graphitic nature of the carbon core. The spectrum of the silicon carbide coating of the fiber reveals similar features to those of single-crystal silicon carbide, indicating that this coating is in the crystalline or polycrystalline phase. (C) 1997 American Institute of Physics. C1 STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. RP Ma, Q (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,ARGONNE,IL 60439, USA. RI Rosenberg, Richard/K-3442-2012 NR 14 TC 2 Z9 2 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 5 PY 1997 VL 70 IS 18 BP 2389 EP 2391 DI 10.1063/1.118881 PG 3 WC Physics, Applied SC Physics GA WZ076 UT WOS:A1997WZ07600019 ER PT J AU Ren, F Lee, JW Abernathy, CR Pearton, SJ Constantine, C Barratt, C Shul, RJ AF Ren, F Lee, JW Abernathy, CR Pearton, SJ Constantine, C Barratt, C Shul, RJ TI Dry etch damage in inductively coupled plasma exposed GaAs/AlGaAs heterojunction bipolar transistors SO APPLIED PHYSICS LETTERS LA English DT Article ID MOMBE; HBTS AB The de current gain and emitter and base sheet resistance of C-doped GaAs/AlGaAs heterojunction bipolar transistors (HBTs) have been used to measure damage introduced by exposure to Ar inductively coupled plasmas (ICP). As the ICP source power is increased at fixed rf chuck power, the damage-induced changes in device characteristics are reduced due to a reduction in ion energy. Beyond a particular ICP source power (similar to 1000 W for 50 W rf chuck power), the damage increases due to the increase in ion flux, even though the ion energy is low (<30 eV). These results are a clear demonstration of the advantage of high ion density plasmas for pattern transfer in damage-sensitive minority carrier devices such as HBTs. (C) 1997 American Institute of Physics. C1 UNIV FLORIDA,DEPT MAT SCI & ENGN,GAINESVILLE,FL 32611. PLASMA THERM IP,ST PETERSBURG,FL 33716. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Ren, F (reprint author), AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974, USA. NR 15 TC 20 Z9 20 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 5 PY 1997 VL 70 IS 18 BP 2410 EP 2412 DI 10.1063/1.118887 PG 3 WC Physics, Applied SC Physics GA WZ076 UT WOS:A1997WZ07600026 ER PT J AU Ashby, CIH Sullivan, JP Newcomer, PP Missert, NA Hou, HQ Hammons, BE Hafich, MJ Baca, AG AF Ashby, CIH Sullivan, JP Newcomer, PP Missert, NA Hou, HQ Hammons, BE Hafich, MJ Baca, AG TI Wet oxidation of AlxGa1-xAs: Temporal evolution of composition and microstructure and the implications for metal-insulator-semiconductor applications SO APPLIED PHYSICS LETTERS LA English DT Article ID GAAS AB Three important processes dominate the wet thermal oxidation of AlxGa1-xAs on GaAs: (I) oxidation of AZ and Ga in the AlxGa1-xAs alloy to form an amorphous oxide, (2) formation and elimination of crystalline and amorphous elemental As and of amorphous As2O3, and (3) crystallization of the amorphous oxide film. Residual As can lead to strong Fermi-level pinning at the oxidized AlGaAs/GaAs interface, up to a 100-fold increase in leakage current, and a 30% increase in the dielectric constant of the oxide layer. Thermodynamically favored interfacial As may impose a fundamental limitation on the use of AlGaAs wet oxidation in metal-insulator-semiconductor devices in the GaAs material system. (C) 1997 American Institute of Physics. RP Ashby, CIH (reprint author), SANDIA NATL LABS,ALBUQUERQUE,NM 87185, USA. NR 9 TC 50 Z9 51 U1 1 U2 7 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 MAY 5 PY 1997 VL 70 IS 18 BP 2443 EP 2445 DI 10.1063/1.118897 PG 3 WC Physics, Applied SC Physics GA WZ076 UT WOS:A1997WZ07600037 ER PT J AU Jin, X Chen, Y Lin, XW Dong, DS Chen, Y Xu, M Zhu, WR Wang, X Shen, XL Li, L AF Jin, X Chen, Y Lin, XW Dong, DS Chen, Y Xu, M Zhu, WR Wang, X Shen, XL Li, L TI Interface structure of fcc Mn on GaAs(001) SO APPLIED PHYSICS LETTERS LA English DT Article ID EPITAXIAL-GROWTH; STABILIZATION; DIAMOND; FILMS; GAAS; CO AB Temperature dependent growth of Mn on GaAs(001) and their interface structure have been studied. At 400 K, fee Mn grows epitaxially on GaAs and a ''Mn2As-type'' Mn-Ga-As mixed layer sandwiched between the fee Mn and GaAs(001)is observed. It is this transition layer that plays a critical role in the stabilization of the metastable fcc-Mn-phase on GaAs(001). (C) 1997 American Institute of Physics. C1 FUDAN UNIV,SURFACE PHYS LAB,SHANGHAI 200433,PEOPLES R CHINA. LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RP Jin, X (reprint author), FUDAN UNIV,FUDAN TD LEE PHYS LAB,SHANGHAI 200433,PEOPLES R CHINA. NR 9 TC 16 Z9 19 U1 2 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 5 PY 1997 VL 70 IS 18 BP 2455 EP 2457 DI 10.1063/1.118854 PG 3 WC Physics, Applied SC Physics GA WZ076 UT WOS:A1997WZ07600041 ER PT J AU Wang, DX Krafft, GA Price, E Wood, PAD Porterfield, DW Crowe, TW AF Wang, DX Krafft, GA Price, E Wood, PAD Porterfield, DW Crowe, TW TI A noninvasive bunch length monitor for femtosecond electron bunches (vol 70, pg 529, 1997) SO APPLIED PHYSICS LETTERS LA English DT Correction, Addition C1 UNIV VIRGINIA,SEMICOND DEVICE LAB,CHARLOTTESVILLE,VA 22903. RP Wang, DX (reprint author), THOMAS JEFFERSON NATL ACCELERATOR FACIL,NEWPORT NEWS,VA 23606, USA. NR 1 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 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD MAY 5 PY 1997 VL 70 IS 18 BP 2481 EP 2481 DI 10.1063/1.119269 PG 1 WC Physics, Applied SC Physics GA WZ076 UT WOS:A1997WZ07600050 ER PT J AU Haschke, JM Ricketts, TE AF Haschke, JM Ricketts, TE TI Adsorption of water on plutonium dioxide SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE plutonium dioxide; water; adsorption; kinetics; equilibrium properties AB Kinetic and equilibrium properties of water adsorption by plutonium dioxide are derived from gravimetric measurements in moist air at room temperature. In combination with mass-time data extracted from literature sources, the results provide a comprehensive picture of the adsorption process and its humidity dependence at 25 degrees C. Water is accommodated by a sequence of distinct steps involving five types of adsorbate-oxide interaction and accumulating ten molecular layers of water (approximately 2.1 mg H2O/m(2) PuO2 surface) at 100% relative humidity. The humidity-dependent first step and the second step involve half molecular layers of water and are attributed to dissociative chemisorption of water as OH. Like the second step, all subsequent processes are first order, but each involves a single molecular layer of H2O. Kinetic and equilibrium results are applied in defining conditions for limiting the re-adsorption of water during handling operations and their relevance to the complex chemistry of the plutonium-oxygen system is outlined. RP Haschke, JM (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 19 TC 36 Z9 49 U1 2 U2 21 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 MAY 5 PY 1997 VL 252 IS 1-2 BP 148 EP 156 DI 10.1016/S0925-8388(96)02627-8 PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XE340 UT WOS:A1997XE34000033 ER PT J AU Klemens, PG Cort, B AF Klemens, PG Cort, B TI Thermodynamic properties of helium bubbles in aged plutonium SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE plutonium; helium bubbles; thermodynamics; aging AB A qualitative model of the thermal properties of helium gas bubbles in aged plutonium metal is developed. Elasticity theory and plasticity are used to calculate the gas pressure inside the bubble. The chemical potential of a gas atom inside a bubble or a vacancy is estimated relative to an interstitial position. It is shown that the bubble expansion is controlled by plastic yield, with the gas pressure of the order of the yield stress sigma(y), in particular p = 2/3 sigma(y). When the metal is at low temperatures (at or below 300 K), surface tension is not operative, since there is no diffusion to move material. When the metal is heated, surface tension becomes operative, but the bubble does not shrink, because elastic forces are reversed. Helium atoms are readily incorporated into existing bubbles. They also have a strong tendency to enter vacancies. This increases the equilibrium vacancy concentration as vacancy-helium complexes. While insignificant at room temperature (300 K), this tendency is important when the metal is heated: when the helium atom concentration increases, helium can migrate into bubbles. The effective pressure of 10 000 atm is then large enough to enable bubbles to grow, overcoming surface tension for bubbles of 5 nm diameter. When the metal is at room temperature, heterogeneous nucleation is required, most likely at grain boundaries. C1 LOS ALAMOS NATL LAB,DIV NUCL MAT TECHNOL,LOS ALAMOS,NM 87545. UNIV CONNECTICUT,DEPT PHYS,STORRS,CT 06268. NR 11 TC 8 Z9 8 U1 2 U2 10 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 MAY 5 PY 1997 VL 252 IS 1-2 BP 157 EP 161 DI 10.1016/S0925-8388(96)02582-0 PG 5 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XE340 UT WOS:A1997XE34000034 ER PT J AU Kleinke, H AF Kleinke, H TI Zr6CoAs2, the first zirconium cobalt arsenide: A new ordered variant of the Fe2P type SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Letter ID CRYSTAL-STRUCTURE; FE2TA9S6; CO2TA9S6; CLUSTERS; PHASES; ZRNBP RP Kleinke, H (reprint author), IOWA STATE UNIV,AMES LAB,DOE,AMES,IA 50011, USA. NR 26 TC 14 Z9 14 U1 0 U2 0 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 MAY 5 PY 1997 VL 252 IS 1-2 BP L29 EP L31 DI 10.1016/S0925-8388(96)03120-9 PG 3 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA XE340 UT WOS:A1997XE34000009 ER PT J AU Petrache, CM Sun, Y Bazzacco, D Lunardi, S Alvarez, CR Falconi, G Venturelli, R Maron, G Napoli, DR Podolyak, Z Walker, PM AF Petrache, CM Sun, Y Bazzacco, D Lunardi, S Alvarez, CR Falconi, G Venturelli, R Maron, G Napoli, DR Podolyak, Z Walker, PM TI High-K bands and oblate-prolate coexistence in Nd-134 SO NUCLEAR PHYSICS A LA English DT Article DE fusion-evaporation; isomeric states; B(M1)/B(E2) ratios; configurations; projected shell model calculations ID HIGH-SPIN STATES; BARRIER PENETRATION; SHAPE COEXISTENCE; QUASI-PARTICLE; ALIGNMENT; NUCLEI; DECAY; SELECTION; HF-174; BA-126 AB Three bands consisting of dipole M1 and quadrupole E2 crossover transitions have been identified in Nd-134 using the GASP array and the Pd-110(Si-28, 4n) reaction at 130 MeV. Calculations with the projected shell model are used to assign configurations to the different bands and to infer their K-composition. The properties of the band built on the I pi = 8(-) isomer confirm the previously assigned two-quasineutron [404]7/2(+) x [514]9/2(-) configuration of the isomeric state. The other two bands are interpreted as coexisting prolate and oblate four-quasiparticle configurations. (C) 1997 Elsevier Science B.V. C1 IST NAZL FIS NUCL,I-35131 PADUA,ITALY. OAK RIDGE NATL LAB,JOINT INST HEAVY ION RES,OAK RIDGE,TN 37831. OAK RIDGE NATL LAB,DIV PHYS,OAK RIDGE,TN 37831. UNIV TENNESSEE,DEPT PHYS & ASTRON,KNOXVILLE,TN 37996. IST NAZL FIS NUCL,LAB NAZL LEGNARO,I-35020 LEGNARO,ITALY. UNIV SURREY,DEPT PHYS,GUILDFORD GU2 5XH,SURREY,ENGLAND. INST PHYS & NUCL ENGN,BUCHAREST,ROMANIA. UNIV BABES BOLYAI,R-3400 CLUJ NAPOCA,ROMANIA. RP Petrache, CM (reprint author), UNIV PADUA,DIPARTIMENTO FIS,I-35131 PADUA,ITALY. RI Petrache, Costel/E-9867-2012; Napoli, Daniel R./D-9863-2012; Sun, Yang/P-2417-2015 OI Petrache, Costel/0000-0001-8419-1390; Napoli, Daniel R./0000-0002-8154-6958; NR 35 TC 15 Z9 15 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD MAY 5 PY 1997 VL 617 IS 2 BP 249 EP 264 DI 10.1016/S0375-9474(97)00036-5 PG 16 WC Physics, Nuclear SC Physics GA WX334 UT WOS:A1997WX33400008 ER PT J AU Grossman, Y Haber, HE AF Grossman, Y Haber, HE TI Sneutrino mixing phenomena SO PHYSICAL REVIEW LETTERS LA English DT Article ID DARK MATTER; SUPERSYMMETRY; SEARCH; MASSES; MODEL AB In any model with nonzero Majorana neutrino masses, the sneutrino and antisneutrino of the supersymmetric extended theory mix. We outline the conditions under which sneutrino-antisneutrino mixing is experimentally observable. The mass splitting of the sneutrino mass eigenstates and sneutrino oscillation phenomena are considered. C1 UNIV CALIF SANTA CRUZ, SANTA CRUZ INST PARTICLE PHYS, SANTA CRUZ, CA 95064 USA. RP STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. NR 29 TC 154 Z9 154 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 5 PY 1997 VL 78 IS 18 BP 3438 EP 3441 DI 10.1103/PhysRevLett.78.3438 PG 4 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800005 ER PT J AU Abe, K Abe, K Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, T Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fernandez, JP Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, S Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, J Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, Y King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWG Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Onoprienko, D Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Schwiening, J Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yashima, J Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J AF Abe, K Abe, K Akagi, T Allen, NJ Ash, WW Aston, D Baird, KG Baltay, C Band, HR Barakat, MB Baranko, G Bardon, O Barklow, T Bashindzhagyan, GL Bazarko, AO BenDavid, R Benvenuti, AC Bilei, GM Bisello, D Blaylock, G Bogart, JR Bolen, B Bolton, T Bower, GR Brau, JE Breidenbach, M Bugg, WM Burke, D Burnett, TH Burrows, PN Busza, W Calcaterra, A Caldwell, DO Calloway, D Camanzi, B Carpinelli, M Cassell, R Castaldi, R Castro, A CavalliSforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G DOliveira, A Damerell, CJS Daoudi, M DeSangro, R DellOrso, R Dervan, PJ Dima, M Dong, DN Du, PYC Dubois, R Eisenstein, BI Elia, R Etzion, E Fahey, S Falciai, D Fan, C Fernandez, JP Fero, MJ Frey, R Furuno, K Gillman, T Gladding, G Gonzalez, S Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, S Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, J Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, Y King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWG Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Onoprienko, D Osborne, LS Panvini, RS Park, CH Park, H Pavel, TJ Peruzzi, I Piccolo, M Piemontese, L Pieroni, E Pitts, KT Plano, RJ Prepost, R Prescott, CY Punkar, GD Quigley, J Ratcliff, BN Reeves, TW Reidy, J Reinertsen, PL Rensing, PE Rochester, LS Rowson, PC Russell, JJ Saxton, OH Schalk, T Schindler, RH Schumm, BA Schwiening, J Sen, S Serbo, VV Shaevitz, MH Shank, JT Shapiro, G Sherden, DJ Shmakov, KD Simopoulos, C Sinev, NB Smith, SR Smy, MB Snyder, JA Stamer, P Steiner, H Steiner, R Strauss, MG Su, D Suekane, F Sugiyama, A Suzuki, S Swartz, M Szumilo, A Takahashi, T Taylor, FE Torrence, E Trandafir, AI Turk, JD Usher, T Vavra, J Vannini, C Vella, E Venuti, JP Verdier, R Verdini, PG Wagner, DL Wagner, SR Waite, AP Watts, SJ Weidemann, AW Weiss, ER Whitaker, JS White, SL Wickens, FJ Williams, DA Williams, DC Williams, SH Willocq, S Wilson, RJ Wisniewski, WJ Woods, M Word, GB Wyss, J Yamamoto, RK Yamartino, JM Yang, X Yashima, J Yellin, SJ Young, CC Yuta, H Zapalac, G Zdarko, RW Zhou, J TI Measurement of leading particle effects in decays of bosons into light flavors SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHYSICS; JETS; SLD AB We present evidence for leading particle production in hadronic decays of the Z(0) boson to light-flavor jets. A polarized electron beam was used to tag quark and antiquark jets, and a vertex detector was employed to reject heavy-flavor events. Charged hadrons were identified with a Cherenkov ring imaging detector. In the quark jets, more high-momentum p, Lambda, K-, and (K) over bar(*0) were observed than their antiparticles, and vice versa for antiquark jets, providing direct evidence that the higher-momentum particles in jets are more likely to carry the primary quark or antiquark from the Z(0) decay, and that s (s) over bar production is suppressed in fragmentation. C1 ADELPHI UNIV, GARDEN CITY, NY 11530 USA. IST NAZL FIS NUCL, I-40126 BOLOGNA, ITALY. BOSTON UNIV, BOSTON, MA 02215 USA. BRUNEL UNIV, UXBRIDGE UB8 3PH, MIDDX, ENGLAND. UNIV CALIF SANTA BARBARA, SANTA BARBARA, CA 93106 USA. UNIV CALIF SANTA CRUZ, SANTA CRUZ, CA 95064 USA. UNIV CINCINNATI, CINCINNATI, OH 45221 USA. COLORADO STATE UNIV, FT COLLINS, CO 80523 USA. UNIV COLORADO, BOULDER, CO 80309 USA. COLUMBIA UNIV, NEW YORK, NY 10027 USA. UNIV FERRARA, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, I-44100 FERRARA, ITALY. IST NAZL FIS NUCL, LAB NAZL FRASCATI, I-00044 FRASCATI, ITALY. UNIV ILLINOIS, URBANA, IL 61801 USA. UNIV CALIF BERKELEY, EO LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. MIT, CAMBRIDGE, MA 02139 USA. UNIV MASSACHUSETTS, AMHERST, MA 01003 USA. UNIV MISSISSIPPI, UNIVERSITY, MS 38677 USA. MOSCOW MV LOMONOSOV STATE UNIV, INST NUCL PHYS, MOSCOW 119899, RUSSIA. UNIV OREGON, EUGENE, OR 97403 USA. IST NAZL FIS NUCL, I-35100 PADUA, ITALY. UNIV PADUA, I-35100 PADUA, ITALY. IST NAZL FIS NUCL, I-06100 PERUGIA, ITALY. UNIV PERUGIA, I-06100 PERUGIA, ITALY. IST NAZL FIS NUCL, I-56100 PISA, ITALY. UNIV PISA, I-56100 PISA, ITALY. RUTGERS STATE UNIV, PISCATAWAY, NJ 08855 USA. RUTHERFORD APPLETON LAB, DIDCOT OX11 0QX, OXON, ENGLAND. SOGANG UNIV, SEOUL, SOUTH KOREA. SOONGSIL UNIV, SEOUL 156743, SOUTH KOREA. STANFORD UNIV, STANFORD LINEAR ACCELERATOR CTR, STANFORD, CA 94309 USA. UNIV TENNESSEE, KNOXVILLE, TN 37996 USA. TOHOKU UNIV, SENDAI, MIYAGI 980, JAPAN. VANDERBILT UNIV, NASHVILLE, TN 37235 USA. UNIV WASHINGTON, SEATTLE, WA 98195 USA. UNIV WISCONSIN, MADISON, WI 53706 USA. YALE UNIV, NEW HAVEN, CT 06511 USA. RP Abe, K (reprint author), NAGOYA UNIV, CHIKUSA KU, NAGOYA, AICHI 464, JAPAN. RI de Sangro, Riccardo/J-2901-2012; Cavalli-Sforza, Matteo/H-7102-2015; Calcaterra, Alessandro/P-5260-2015; Frey, Raymond/E-2830-2016; OI de Sangro, Riccardo/0000-0002-3808-5455; Calcaterra, Alessandro/0000-0003-2670-4826; Frey, Raymond/0000-0003-0341-2636; pieroni, enrico/0000-0002-4246-6963; Wyss, Jeffery/0000-0002-8277-4012 NR 22 TC 23 Z9 23 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 5 PY 1997 VL 78 IS 18 BP 3442 EP 3446 DI 10.1103/PhysRevLett.78.3442 PG 5 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800006 ER PT J AU Haslip, DS Flibotte, S deFrance, G Devlin, M GalindoUribarri, A Gervais, G Hackman, G LaFosse, DR Lee, IY Lerma, F Macchiavelli, AO MacLeod, RW Mullins, SM Nieminen, JM Sarantites, DG Svensson, CE Waddington, JC Wilson, JN AF Haslip, DS Flibotte, S deFrance, G Devlin, M GalindoUribarri, A Gervais, G Hackman, G LaFosse, DR Lee, IY Lerma, F Macchiavelli, AO MacLeod, RW Mullins, SM Nieminen, JM Sarantites, DG Svensson, CE Waddington, JC Wilson, JN TI Delta I=4 bifurcation in identical superdeformed bands SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAY COINCIDENCE DATA; BACKGROUND SUBTRACTION; C-4 SYMMETRY; NUCLEI; ALIGNMENT AB Delta l = 4 bifurcation has been observed in two superdeformed bands, the newly discovered yrast superdeformed band of (EU)-E-148, and a previously known excited band in Gd-148. Both of these bands have moments of inertia that are identical to the yrast band of Gd-149, the first superdeformed band in which this bifurcation was observed. This first observation of Delta I = 4 bifurcation in identical superdeformed bands provides a crucial test of recent models. C1 CTR RECH NUCL,F-67037 STRASBOURG 2,FRANCE. UNIV STRASBOURG 1,F-67037 STRASBOURG 2,FRANCE. WASHINGTON UNIV,DEPT CHEM,ST LOUIS,MO 63130. ATOM ENERGY CANADA LTD,CHALK RIVER LABS,CHALK RIVER,ON K0J 1J0,CANADA. ARGONNE NATL LAB,ARGONNE,IL 60439. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV NUCL SCI,BERKELEY,CA 94720. AUSTRALIAN NATL UNIV,RES SCH PHYS SCI & ENGN,DEPT PHYS NUCL,CANBERRA,ACT 0200,AUSTRALIA. RP Haslip, DS (reprint author), MCMASTER UNIV,DEPT PHYS & ASTRON,HAMILTON,ON L8S 4M1,CANADA. RI Devlin, Matthew/B-5089-2013 OI Devlin, Matthew/0000-0002-6948-2154 NR 29 TC 42 Z9 43 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 5 PY 1997 VL 78 IS 18 BP 3447 EP 3450 DI 10.1103/PhysRevLett.78.3447 PG 4 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800007 ER PT J AU Chen, SY Cao, NZ AF Chen, SY Cao, NZ TI Anomalous scaling and structure instability in three-dimensional passive scalar turbulence SO PHYSICAL REVIEW LETTERS LA English DT Article ID REFINED SIMILARITY HYPOTHESES; DEVELOPED TURBULENCE; ISOTROPIC TURBULENCE; VELOCITY INCREMENTS; DISSIPATION; INTERMITTENCY; FLUCTUATIONS; FLUID; FLOWS AB The anomalous scaling phenomena of three-dimensional passive scalar turbulence are studied using high resolution direct numerical simulation. The inertial range scaling exponents of the passive scalar increment and the scalar dissipation are obtained. The connection between the intermittency structure and the scaling exponent is examined and the structure instability of the high amplitude scalar dissipation is used to clarify previous experimental results for the scaling exponents. C1 LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Chen, SY (reprint author), IBM CORP,DIV RES,THOMAS J WATSON RES CTR,POB 218,YORKTOWN HTS,NY 10598, USA. RI Chen, Shiyi/A-3234-2010 NR 38 TC 32 Z9 33 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 5 PY 1997 VL 78 IS 18 BP 3459 EP 3462 DI 10.1103/PhysRevLett.78.3459 PG 4 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800010 ER PT J AU Schmid, AK Bartelt, NC Hamilton, JC Carter, CB Hwang, RQ AF Schmid, AK Bartelt, NC Hamilton, JC Carter, CB Hwang, RQ TI Brownian motion of dislocations in thin films SO PHYSICAL REVIEW LETTERS LA English DT Article ID METAL-METAL INTERFACES; AU(111) SURFACE; RECONSTRUCTION; RU(0001); CU; RELAXATION AB The motion of edge dislocations in a single monolayer film of Cu on Ru(0001) was studied by time-resolved scanning tunneling microscopy. The dislocations were observed to make rapid ID random walks in the film: This dislocation motion is attributed to the equilibrium thermal exchange of atoms: between the solid film and the adatom gas covering the film. These results highlight a fundamental difference between the dynamics of dislocations in thin films and the bulk, which is in principle important in understanding the mechanical properties of thin films. C1 UNIV MINNESOTA,DEPT CHEM ENGN & MAT SCI,MINNEAPOLIS,MN 55455. RP Schmid, AK (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94551, USA. RI Carter, C. Barry/E-6478-2010 OI Carter, C. Barry/0000-0003-4251-9102 NR 13 TC 30 Z9 30 U1 4 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 5 PY 1997 VL 78 IS 18 BP 3507 EP 3510 DI 10.1103/PhysRevLett.78.3507 PG 4 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800022 ER PT J AU Dubon, OD Walukiewicz, W Beeman, JW Haller, EE AF Dubon, OD Walukiewicz, W Beeman, JW Haller, EE TI Direct observation of the Hubbard gap in a semiconductor SO PHYSICAL REVIEW LETTERS LA English DT Article ID UNIAXIAL-STRESS; GROUND-STATE; GERMANIUM AB The transformation of the ground state of Cu accepters in uniaxially stressed Ge from the (1s)(3) to the (1s)(2)(2s)(1) configuration results in a unique system in which a highly delocalized hole wave function corresponds to a relatively deep electronic state. This leads to electronic conduction via an isolated impurity band within the Ge band gap. By changing the Cu concentration we observe an evolution of the Hubbard gap for the 2s state from the full gap of 3.7 meV at 3 x 10(14) cm(-3) to zero gap at 1.6 x 10(16) cm(-3), in good agreement with our calculations. RP Dubon, OD (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. NR 22 TC 8 Z9 8 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 MAY 5 PY 1997 VL 78 IS 18 BP 3519 EP 3522 DI 10.1103/PhysRevLett.78.3519 PG 4 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800025 ER PT J AU Recchia, CH Martindale, JA Pennington, CH Hults, WL Smith, JL AF Recchia, CH Martindale, JA Pennington, CH Hults, WL Smith, JL TI NMR and vortex lattice melting in YBa2Cu3O7 SO PHYSICAL REVIEW LETTERS LA English DT Article ID SPIN-ECHO DECAY; Y-89 NMR; TRANSVERSE RELAXATION; NUCLEAR-RELAXATION; DYNAMICS; MOTION; TC AB We report Y-89 and O-17 NMR (9 T) echo decays for YBa2Cu3O7 and correct for contributions from dipolar coupling Cu-63,Cu-65 in, order to isolate effects of vortex dynamics. We confirm vortex localization in the solid state with rms displacements consistent with Langevin dynamical theory, but with motional dynamics at time scales (10-100 mu s) some similar to 10(6) times slower than predicted. Vortex migration over longer time scales is restricted to distances less than 1/100 of an intervortex spacing over times as long as 100 ms, in contrast with the rapid long range diffusion occurring in the liquid state. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Recchia, CH (reprint author), OHIO STATE UNIV,DEPT PHYS,174 W 18TH AVE,COLUMBUS,OH 43210, USA. NR 27 TC 34 Z9 34 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD MAY 5 PY 1997 VL 78 IS 18 BP 3543 EP 3546 DI 10.1103/PhysRevLett.78.3543 PG 4 WC Physics, Multidisciplinary SC Physics GA WX518 UT WOS:A1997WX51800031 ER PT J AU Orel, AE Rescigno, TN AF Orel, AE Rescigno, TN TI Photoionization of ammonia SO CHEMICAL PHYSICS LETTERS LA English DT Article ID CROSS-SECTION CALCULATIONS; KOHN VARIATIONAL METHOD; H2O; NH3; IONIZATION AB We report the results of separated-channel, frozen core calculations of partial and total photoionization cross sections and asymmetry parameters for NH3. The calculations were performed using the complex Kohn variational method. The results for the total and partial cross sections agree well with experiment as well as previous theoretical calculations. The asymmetry parameters are found to be a more sensitive test of the accuracy of the wave function. C1 LAWRENCE LIVERMORE NATL LAB,PHYS & SPACE TECHNOL DIRECTORATE,LIVERMORE,CA 94550. RP Orel, AE (reprint author), LAWRENCE LIVERMORE NATL LAB,DEPT APPL SCI,LIVERMORE,CA 94550, USA. NR 23 TC 7 Z9 7 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 2 PY 1997 VL 269 IS 3-4 BP 222 EP 226 DI 10.1016/S0009-2614(97)00283-2 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WW870 UT WOS:A1997WW87000006 ER PT J AU Werst, DW Han, P Trifunac, AD AF Werst, DW Han, P Trifunac, AD TI Trap-to-trap hole transfer studied by radiolysis/EPR. Radical cations in freon and zeolite matrices SO CHEMICAL PHYSICS LETTERS LA English DT Article ID ELECTRON-SPIN-RESONANCE; ION MOLECULE REACTIONS; POSITIVE-CHARGE; H-MORDENITE; ESR; ISOMERIZATION; PAIRS; ZSM-5; ETHER; 77-K AB Electron paramagnetic resonance (EPR) spectroscopy was used to assess the positive charge distribution in irradiated solid samples containing mixtures of donor molecules. The relative trap populations were determined from the EPR intensities of the respective radical cations of the olefinic donors. The occurrence of trap-to-trap hole transfer was examined as a function of the donor pair, donor concentration, and matrix. Three matrices were studied: CF3CCl3 CFCl3, and ZSM5 zeolite. The concentration dependence of the final charge distributions in some cases reflected the occurrence of resonant charge transfer. Surprising differences between CF3CCl3 and CFCl3 are explained by differences in matrix chemistry. The radiolysis/EPR technique applied to double-loaded zeolites serves as a method of probing the intracrystalline adsorption distributions and mobilities of guest species in zeolites. RP Werst, DW (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 35 TC 15 Z9 15 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 2 PY 1997 VL 269 IS 3-4 BP 333 EP 340 DI 10.1016/S0009-2614(97)00295-9 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WW870 UT WOS:A1997WW87000023 ER PT J AU Ambrose, WP Goodwin, PM Enderlein, J Semin, DJ Martin, JC Keller, RA AF Ambrose, WP Goodwin, PM Enderlein, J Semin, DJ Martin, JC Keller, RA TI Fluorescence photon antibunching from single molecules on a surface SO CHEMICAL PHYSICS LETTERS LA English DT Article ID OPTICAL MICROSCOPY; RADIATION AB Fluorescence correlation spectroscopy of individual Rhodamine 6G (R6G) molecules immobilized on a silica surface is performed in air at room temperature using confocal laser scanning optical microscopy (CLSM). The high excitation irradiance in CLSM is used to saturate single R6G molecules, and to observe fluorescence photon antibunching. An experimental arrangement is described that improves the overall coincidence counting efficiency at high irradiance. Photophysical parameters obtained from the saturation data are used to model the antibunching behavior. This is the first reported example of photon antibunching from individual quantum systems on a surface. RP Ambrose, WP (reprint author), LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,MAIL STOP M888,LOS ALAMOS,NM 87545, USA. NR 33 TC 63 Z9 63 U1 4 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD MAY 2 PY 1997 VL 269 IS 3-4 BP 365 EP 370 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WW870 UT WOS:A1997WW87000027 ER PT J AU Edwards, RL Cheng, H Murrell, MT Goldstein, SJ AF Edwards, RL Cheng, H Murrell, MT Goldstein, SJ TI Protactinium-231 dating of carbonates by thermal ionization mass spectrometry: Implications for quaternary climate change SO SCIENCE LA English DT Article ID LAST INTERGLACIAL PERIOD; HOLE CALCITE VEIN; U-TH AGES; DEVILS-HOLE; TH-230 AGES; SEA LEVELS; C-14 AGES; CORALS; BARBADOS; SYSTEMATICS AB Measurement of protactinium-231 (Pa-231) in carbonates by thermal ionization mass spectroscopy yields Pa-231 ages that are more than 10 times more precise than those determined by decay counting. Carbonates between 10 and 250,000 years old can now be dated with Pa-231 methods. Barbados corals that have identical Pa-231 and thorium-230 (Th-230) ages indicate that the timing of sea level change over parts of the last glacial cycle is consistent with the predictions of the Astronomical Theory. Two Devils Hole calcite subsamples record identical Pa-231 and Th-230 ages, suggesting that the chronology of this climate record is accurate. C1 LOS ALAMOS NATL LAB, CHEM SCI & TECHNOL DIV, LOS ALAMOS, NM 87545 USA. RP UNIV MINNESOTA, DEPT GEOL & GEOPHYS, MINNESOTA ISOTOPE LAB, MINNEAPOLIS, MN 55455 USA. NR 47 TC 133 Z9 136 U1 3 U2 25 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD MAY 2 PY 1997 VL 276 IS 5313 BP 782 EP 786 DI 10.1126/science.276.5313.782 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WW900 UT WOS:A1997WW90000054 ER PT J AU Stowell, MHB McPhillips, TM Rees, DC Soltis, SM Abresch, E Feher, G AF Stowell, MHB McPhillips, TM Rees, DC Soltis, SM Abresch, E Feher, G TI Light-induced structural changes in photosynthetic reaction center: Implications for mechanism of electron-proton transfer SO SCIENCE LA English DT Article ID SPHAEROIDES REACTION CENTERS; BACTERIAL REACTION CENTERS; RHODOBACTER-SPHAEROIDES; RHODOPSEUDOMONAS-SPHAEROIDES; CRYOGENIC TEMPERATURES; PARAMAGNETIC-RESONANCE; TRANSFER KINETICS; FREE-ENERGY; RESOLUTION; PATHWAY AB High resolution x-ray diffraction data from crystals of the Rhodobacter sphaeroides photosynthetic reaction center (RC) have been collected at cryogenic temperature in the dark and under illumination, and the structures were refined at 2.2 and 2.6 angstrom resolution, respectively. In the charge-separated D(+)Q(A)Q(B)(-) state (where D is the primary electron donor (a bacteriochlorophyll dimer), and Q(A) and Q(B) are the primary and secondary quinone accepters, respectively), Q(B)(-) is located approximately 5 angstroms from the Q(B) position in the charge-neutral (DQ(A)Q(B)) slate, and has undergone a 180 degrees propeller twist around the isoprene chain. A model based on the difference between the two structures is proposed to explain the observed kinetics of electron transfer from Q(A)-Q(B) to Q(A)Q(B)(-) and the relative binding affinities of the different ubiquinone species in the Q(B) pocket. In addition, several water channels (putative proton pathways) leading from the Q(B) pocket to the surface of the RC were delineated, one of which leads directly to the membrane surface. C1 CALTECH,DIV CHEM & CHEM ENGN,PASADENA,CA 91125. STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. UNIV CALIF SAN DIEGO,DEPT PHYS,LA JOLLA,CA 92093. RI Feher, George/E-3050-2010 FU NIGMS NIH HHS [GM13191, GM45162] NR 64 TC 654 Z9 679 U1 2 U2 60 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 2 PY 1997 VL 276 IS 5313 BP 812 EP 816 DI 10.1126/science.276.5313.812 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WW900 UT WOS:A1997WW90000063 PM 9115209 ER PT J AU Thurnauer, MC Rajh, T Tiede, DM AF Thurnauer, MC Rajh, T Tiede, DM TI Surface modification of TiO2: Correlation between structure, charge separation and reduction properties SO ACTA CHEMICA SCANDINAVICA LA English DT Article; Proceedings Paper CT 1st National Symposium on Environmental Chemistry CY NOV 20-21, 1995 CL ROME, ITALY SP Italian Chem Soc, Environm Chem Div, Univ Rome La Sapienza, Natl Res Council, Rome ID POTENTIALS; PARTICLES; RADICALS AB Surface complexation of colloidal titanium dioxide nanoparticles (40 Angstrom, anatase structure) by alpha-mercapto-substituted carboxylic acid results in the formation of a charge transfer complex with an optical absorption threshold at 520 nm. It was found by EPR spectroscopy that illumination of these surface-modified TiO2 particle, which leads to the charge transfer complex and/or band gap excitation, results in the efficient spatial separation of photoinduced charges. Photogenerated holes are transferred to the derivatives at 4.2 K, while photogenerated electrons are trapped on the TiO2 particle. Visible excitation (400 nm cut-off filter) results in localization of photogenerated holes on the carboxy group, while UV excitation results in localization on the most distant hydrocarbon group of the derivative. Both band gap and CT excitation of TiO2 lead to the reduction of Pb2+ ions to metallic lead (E degrees = -0.126 V vs. NHE), while only band gap excitation leads to the reduction of Cd2+ ions to its metallic form (E degrees = -0.405 V). The EPR signal for trapped electrons disappeared as a result of the reduction of Pb2+ or Cd2+ ions, and metallic lead was observed to precipitate. RP Thurnauer, MC (reprint author), ARGONNE NATL LAB,DIV CHEM,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 23 TC 51 Z9 54 U1 0 U2 8 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 MAY PY 1997 VL 51 IS 5 BP 610 EP 618 DI 10.3891/acta.chem.scand.51-0610 PG 9 WC Biochemistry & Molecular Biology; Chemistry, Multidisciplinary SC Biochemistry & Molecular Biology; Chemistry GA WZ828 UT WOS:A1997WZ82800013 ER PT J AU Szoke, A Szoke, H Somoza, JR AF Szoke, A Szoke, H Somoza, JR TI Holographic methods in X-ray crystallography .5. Multiple isomorphous replacement, multiple anomalous dispersion and non-crystallographic symmetry SO ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES LA English DT Article ID ABINITIO PHASE DETERMINATION; MACROMOLECULAR CRYSTALLOGRAPHY; CONSTRAINTS; REAL; REFINEMENT; VIRUSES; MAPS AB The holographic method for the recovery of the electron density of macromolecules is based on the expansion of the electron density into Gaussian basis functions. The technique makes consistent use of real- and reciprocal-space information to produce electron-density maps. It enforces positivity of the recovered electron density and makes effective use of previously known information about the electron density, such as knowledge of a solvent region or knowledge of a partial structure. In this paper, we summarize the theory underlying the holographic method, and describe how we extend the range of information that can be used by the method to include information from multiple-isomorphous-replacement (MLR) data, multiple-anomalous-dispersion (MAD) data and knowledge of non-crystallographic symmetry. The convergence properties and the limiting accuracy of the method are discussed. Its power for synthetic problems is demonstrated and the method is applied to experimentally measured MIR data from kinesin, a motor protein domain that has recently been solved. Appendix A gives a detailed description of the algorithms and the equations used in EDEN, the computer program that implements the holographic method. C1 UNIV CALIF SAN FRANCISCO, DEPT BIOCHEM & BIOPHYS, SAN FRANCISCO, CA 94143 USA. RP Szoke, A (reprint author), LAWRENCE LIVERMORE NATL LAB, LIVERMORE, CA 94550 USA. NR 36 TC 20 Z9 20 U1 1 U2 2 PU INT UNION CRYSTALLOGRAPHY PI CHESTER PA 2 ABBEY SQ, CHESTER, CH1 2HU, ENGLAND SN 2053-2733 J9 ACTA CRYSTALLOGR A JI Acta Crystallogr. Sect. A PD MAY 1 PY 1997 VL 53 BP 291 EP 313 DI 10.1107/S010876739601584X PN 3 PG 23 WC Chemistry, Multidisciplinary; Crystallography SC Chemistry; Crystallography GA XB241 UT WOS:A1997XB24100005 ER PT J AU Hung, LW Kohmura, M Ariyoshi, Y Kim, SH AF Hung, LW Kohmura, M Ariyoshi, Y Kim, SH TI Crystallization and preliminary X-ray analysis of D-monellin SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID SWEET PROTEIN MONELLIN; SOLID-PHASE SYNTHESIS; CHAIN MONELLIN; ANALOGS AB D-Monellin is a chemically synthesized protein composed of all D-amino acids. It has an amino-acid sequence identical to L-monellin, a natural protein with potent sweetness. Two crystal forms of D-monellin were obtained. Both crystals were grown under conditions similiar to those used to crystallize natural L-monellin. Crystal form I has similar, but not identical, cell parameters to natural L-monellin and diffracts to 2.7 Angstrom resolution. Crystal form II is very different and diffracts to 1.7 Angstrom resolution using synchrotron radiation. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. AJINOMOTO CO INC,CENT RES LABS,KAWASAKI KU,KAWASAKI,KANAGAWA 210,JAPAN. RP Hung, LW (reprint author), UNIV CALIF BERKELEY,DEPT CHEM,GRAD GRP BIOPHYS,BERKELEY,CA 94720, USA. NR 10 TC 5 Z9 5 U1 1 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0907-4449 J9 ACTA CRYSTALLOGR D JI Acta Crystallogr. Sect. D-Biol. Crystallogr. PD MAY 1 PY 1997 VL 53 BP 327 EP 328 DI 10.1107/S0907444996014989 PN 3 PG 2 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA XB256 UT WOS:A1997XB25600013 PM 15299937 ER PT J AU CossyFavre, A Diaz, J Anders, S Padmore, H Liu, Y Samant, M Stohr, J Brown, H Russell, TP AF CossyFavre, A Diaz, J Anders, S Padmore, H Liu, Y Samant, M Stohr, J Brown, H Russell, TP TI Photoelectron emission microscopy and its application to the study of polymer surfaces SO ACTA PHYSICA POLONICA A LA English DT Article; Proceedings Paper CT 3rd International School and Symposium on Synchrotron Radiation in Natural Science (ISSRNS) CY MAY 31-JUN 08, 1996 CL POLISH SYNCHROTRON RADIATION SOCIETY, JASZOWIEC, POLAND HO POLISH SYNCHROTRON RADIATION SOCIETY ID SYNCHROTRON RADIATION; ELECTROSTATIC LENSES; PHASE-SEPARATION; SPECTROSCOPY; ABERRATION AB The X-ray photoelectron emission microscopy at the Advanced Light Source has a spatial resolution of 0.2 microns at an accelerating voltage of 12 kV. The tunability of the photon energy is used to provide chemical state information using near edge X-ray absorption fine structure spectroscopy on the sub-micrometer scale. The homogeneity of thin films of polymer blends was studied for various film thicknesses. The polystyrene/polyvinylmethylether film of 194 Angstrom showed protrusions of 2-3 mu m diameter with an enriched polystyrene content while the polystyrene/polystyreneacrylonitrile 504 Angstrom thick films showed 5-6 mu m segregated regions without any topological structure. C1 IBM CORP,ALMADEN RES CTR,SAN JOSE,CA 95120. RP CossyFavre, A (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Diaz, Javier/F-2381-2016; Raoux, Simone/G-3920-2016 NR 14 TC 4 Z9 4 U1 1 U2 2 PU POLISH ACAD SCIENCES INST PHYSICS PI WARSAW PA AL LOTNIKOW 32-46, 02-668 WARSAW, POLAND SN 0587-4246 J9 ACTA PHYS POL A JI Acta Phys. Pol. A PD MAY PY 1997 VL 91 IS 5 BP 923 EP 927 PG 5 WC Physics, Multidisciplinary SC Physics GA XA626 UT WOS:A1997XA62600015 ER PT J AU Melles, M AF Melles, M TI Exact results on O(alpha(2)) single bremsstrahlung corrections to low angle Bhabha scattering at LEP/SLC energies SO ACTA PHYSICA POLONICA B LA English DT Article ID MULTIPLE BREMSSTRAHLUNG; GAUGE-THEORIES; HELICITY AMPLITUDES; LEP; EXPONENTIATION AB In this thesis exact results on O(alpha(2)) Single bremsstrahlung corrections to low angle Bhabha scattering at LEP/SLC energies ale given. The calculation represents the last outstanding. theoretical second order subleading electroweak contribution for that process, needed to determine the experimental luminosity at second generation LEP detectors below the 0.1% precision threshold. The exact, fully differential result is obtained by employing analytical as well as computer-algebraic methods and includes terms up to O(0.05%) relative to the Born cross section. The initial output of over 20,000 terms could be reduced to 90, only 18 of which are shown to be numerically relevant and for which a simple logarithmic ansatz is derived, that is in remarkable agreement with the complete answer. Strong consistency checks are performed, including Ward-Takahashi identities and tests on the right infrared limit according to the Yennie, Frautschi and Suura program. Monte Carlo results for the integrated cross section are compared with existing: calculations in the leading logarithmic approximation for a chosen set of experimental cuts. The size of the missing subleading terms is found to be small but non negligible in the context of setting: stringent limits on Standard Model predictions and thus its realm of validity. RP Melles, M (reprint author), STANFORD UNIV,STANFORD LINEAR ACCELERATOR CTR,STANFORD,CA 94309, USA. NR 45 TC 10 Z9 10 U1 0 U2 0 PU ACTA PHYSICA POLONICA B, JAGELLONIAN UNIV, INST PHYSICS PI KRAKOW PA REYMONTA 4, 30-059 KRAKOW, POLAND SN 0587-4254 J9 ACTA PHYS POL B JI Acta Phys. Pol. B PD MAY PY 1997 VL 28 IS 5 BP 1159 EP 1205 PG 47 WC Physics, Multidisciplinary SC Physics GA XB043 UT WOS:A1997XB04300010 ER PT J AU Cheng, Q Stevens, RC AF Cheng, Q Stevens, RC TI Coupling of an induced fit enzyme to polydiacetylene thin films: Colorimetric detection of glucose SO ADVANCED MATERIALS LA English DT Article ID YEAST HEXOKINASE AB A new biosensor design is demonstrated, in which a protein conformational change is used as a trigger mechanism for a low-cost, solid-state sensor (see also the cover). The figure illustrates the principle: an enzyme (hexokinase, large white shape) immobilized on a lipid polydiacetylene (PDA) layer undergoes a conformational change when glucose (dark shape) binds to it. The resulting stress in the PDA layer produces a color change. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV MAT SCI,BERKELEY,CA 94720. RI Cheng, Jason/C-6345-2011; Stevens, Raymond/K-7272-2015 OI Stevens, Raymond/0000-0002-4522-8725 NR 9 TC 107 Z9 107 U1 7 U2 41 PU WILEY-V C H VERLAG GMBH PI WEINHEIM PA POSTFACH 10 11 61, D-69451 WEINHEIM, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD MAY PY 1997 VL 9 IS 6 BP 481 EP & DI 10.1002/adma.19970090605 PG 4 WC Chemistry, Multidisciplinary; Chemistry, Physical; Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied; Physics, Condensed Matter SC Chemistry; Science & Technology - Other Topics; Materials Science; Physics GA WZ682 UT WOS:A1997WZ68200004 ER PT J AU Alvin, KF AF Alvin, KF TI Finite element model update via Bayesian estimation and minimization of dynamic residuals SO AIAA JOURNAL LA English DT Article ID STIFFNESS; IDENTIFICATION; IMPROVEMENT; ADJUSTMENT AB An algorithm is presented for updating finite element models based on a minimization of dynamic residuals, The dynamic residual of interest is the force unbalance in the homogeneous form of the equations of motion arising from errors in the model's mass and stiffness when evaluated with the identified modal parameters, The algorithm is a modification and extension of a previously developed sensitivity-based element-by-element (SB-EBE) method for damage detection and finite element model updating. SB-EBE is generalized to minimize a dynamic displacement residual quantity, which is shown to improve test-analysis mode correspondence, Furthermore, the algorithm is modified to include Bayesian estimation concepts, and the underlying nonlinear optimization problem is consistently linearized to improve the convergence properties, The resulting algorithm is demonstrated via numerical and experimental examples to be an efficient and robust method for both localizing model errors and estimating physical parameters. RP Alvin, KF (reprint author), SANDIA NATL LABS,STRUCT DYNAM & VIBRAT CONTROL DEPT,TECH STAFF,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 21 TC 41 Z9 45 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0001-1452 J9 AIAA J JI AIAA J. PD MAY PY 1997 VL 35 IS 5 BP 879 EP 886 DI 10.2514/2.7462 PG 8 WC Engineering, Aerospace SC Engineering GA WY030 UT WOS:A1997WY03000018 ER PT J AU Williams, PT AF Williams, PT TI Evidence for the incompatibility of age-neutral overweight and age-neutral physical activity standards from runners SO AMERICAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE exercise; running; physical activity; adiposity; weight gain; regional adiposity; middle aged men ID WEIGHT-GAIN; BODY-WEIGHT; COMPUTED-TOMOGRAPHY; ENERGY-EXPENDITURE; HEALTH-PROFESSIONALS; FAT DISTRIBUTION; ADIPOSE-TISSUE; MEN; EXERCISE; OBESITY AB In contrast with earlier versions, the 1995 Dietary Guidelines for Americans uses the same definition of overweight for both younger and older adults. These guidelines state that prevention of weight gain at any age is achievable by balancing food intake with physical activity. The purposes of our study were to assess I) whether vigorous exercise prevents weight gain with age, and 2) whether weight maintenance and an age-neutral adult overweight standard are consistent with a constant activity level over time. These hypotheses were tested in a national cross-sectional survey of 4769 and 2150 male runners aged 18-49 y and > 49 y, respectively. Before age 50 y, the rates at which body mass index (BMI; in kg/m(2)) and waist circumference increased in association with age were the same in shorter-distance (< 16 km/wk) and longer-distance (> 80 km/wk) runners. Regardless of weekly running distance, before age 50 y, BMI increased at (+/-SE) 0.045 +/- 0.006 kg.m(-2) y(-1) and waist circumference increased at 0.186 +/- 0.014 cm/y. The percentage of runners who were moderately overweight (BMI greater than or equal to 25) was 21.5% before age 30 y and 30.1% in those between 45 and 49 y old. Men who ran greater distances were nevertheless leaner because weekly running distance was inversely related to BMI (slope +/- SE: -0.033 +/- 0.002 kg/m(2) per km/wk) and waist circumference (-0.083 +/- 0.004 cm.km(-1).wk(-1)). To be consistent, guidelines should either II recommend substantial increases in physical activity over time when promoting an age-neutral adult overweight standard, or 2) accept an age-adjusted overweight standard when recommending a constant level of physical activity over time. RP Williams, PT (reprint author), UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, LIFE SCI DIV, BLDG 934, BERKELEY, CA 94720 USA. FU NHLBI NIH HHS [HL-45652] NR 44 TC 32 Z9 33 U1 0 U2 1 PU AMER SOC NUTRITION-ASN PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0002-9165 EI 1938-3207 J9 AM J CLIN NUTR JI Am. J. Clin. Nutr. PD MAY PY 1997 VL 65 IS 5 BP 1391 EP 1396 PG 6 WC Nutrition & Dietetics SC Nutrition & Dietetics GA WW078 UT WOS:A1997WW07800004 PM 9129467 ER PT J AU Ramsey, GP AF Ramsey, GP TI A simplified approach to collision processes SO AMERICAN JOURNAL OF PHYSICS LA English DT Article AB We present an approach to two-body collision processes which simplifies the algebra and leads to a convenient geometrical visualization of these processes in the velocity plane. Special cases, such as the lab and center-of-mass frames, can easily be extracted from the general solutions without further algebra. The geometric interpretation provides insight into the dynamics of collisions without having to consider numerous special cases, Thus important physics concepts can be illustrated without students becoming lost in the algebra. (C) 1997 American Association of Physics Teachers. C1 ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439. RP Ramsey, GP (reprint author), LOYOLA UNIV,DEPT PHYS,CHICAGO,IL 60626, USA. NR 11 TC 3 Z9 3 U1 0 U2 1 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 MAY PY 1997 VL 65 IS 5 BP 384 EP 389 DI 10.1119/1.18549 PG 6 WC Education, Scientific Disciplines; Physics, Multidisciplinary SC Education & Educational Research; Physics GA WX186 UT WOS:A1997WX18600006 ER PT J AU Goldberg, SA Dallmeyer, RD AF Goldberg, SA Dallmeyer, RD TI Chronology of Paleozoic metamorphism and deformation in the Blue Ridge thrust complex, North Carolina and Tennessee SO AMERICAN JOURNAL OF SCIENCE LA English DT Review ID PB ZIRCON AGES; SOUTHERN APPALACHIANS; CLOSURE TEMPERATURES; DUCTILE DEFORMATION; TECTONIC EVOLUTION; TAUERN WINDOW; EASTERN ALPS; K-AR; GARNET; ND AB The Blue Ridge province in northwestern North Carolina and northeastern Tennessee records a multiphase collisional and accretionary history from the Mesoproterozoic through the Paleozoic. To constrain the tectonothermal evolution in this region, radiometric ages have been determined for 23 regionally metamorphosed amphibolites, granitic gneisses, and pelitic schists and from mylonites along shear zones that bound thrust sheets and within an internal shear zone. Samples were collected along a northwest-southeast traverse across three crystalline thrust sheets located west of the Grandfather Mountain window. Ordovician metamorphic mineral ages (Llanvirnian to Caradocian) are recorded in the highest thrust sheets within the Blue Ridge thrust complex. Six samples of metapelite and amphibolite from the Spruce Pine thrust sheet and five samples of basement gneiss and metagabbro from the Pumpkin Patch thrust sheet yield Sm-Nd and Rb-Sr garnet ages of 460 to 450 Ma and hornblende ages of 472 to 451 Ma In addition, multiple mineral isochron ages of 457 +/- 2 and 458 +/- 17 Ma were obtained from a Pumpkin Patch metagabbro. The garnet ages from the Pumpkin Patch thrust sheet (458, 455, and 451 Ma) are similar to those from the structurally overlying Spruce Pine thrust sheet (460, 456, 455, 455, and 450 Ma). Both thrust sheets exhibit similar upper amphibolite-facies conditions. Because of the high closure temperature for garnet, the garnet ages are interpreted to date growth at or near the peak of Taconic metamorphism. Devonian metamorphic ages are recognized in the Spruce Pine thrust sheet, where Sm-Nd and Rb-Sr garnet ages of 386 and 393 Ma and mineral isochron ages of 397 +/- 14 and 375 +/- 27 Ma are preserved. Hornblendes record similar Ar-40/Ar-39, Sm-Nd, and Rb-Sr ages of 398 to 379 Ma. Devonian Ar-40/Ar-39 hornblende ages are also recorded in the structurally lower Pumpkin Patch thrust sheet. The Devonian mineral ages are interpreted to date a discrete tectonothermal event, as opposed to uplift and slow cooling from an Ordovician metamorphic event This interpretation is based in part on the fact that Devonian and Ordovician mineral ages are intermixed spatially within the Spruce Pine and Pumpkin Patch thrust sheets. Ar-40/Ar-39 muscovite ages from regionally metamorphosed rocks indicate that much of the Blue Ridge slowly to temperatures of about 375 degrees C by the Late Mississippian. White micas from mylonite 328, and 336 Ma and Rb-Sr ages of 324, 324, 526, and 326 Ma. These reflect the age of Late Mississippian mylonitization (mica growth below or near respective Sr and AE closure temperatures). The Mississippian mylonitization is interpreted to represent thrusting and initial assembly of crystalline sheets associated with the Alleghanian orogeny. The composite thrust stack of the Blue Ridge complex was subsequently thrust northwestward along the Linville Fans fault during middle Alleghanian orogeny (about 300 Ma). C1 UNIV GEORGIA, DEPT GEOL, ATHENS, GA 30602 USA. RP DEPT ENERGY, NEW BRUNSWICK LAB, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 116 TC 39 Z9 39 U1 1 U2 5 PU AMER JOURNAL SCIENCE PI NEW HAVEN PA YALE UNIV, PO BOX 208109, NEW HAVEN, CT 06520-8109 USA SN 0002-9599 EI 1945-452X J9 AM J SCI JI Am. J. Sci. PD MAY PY 1997 VL 297 IS 5 BP 488 EP 526 PG 39 WC Geosciences, Multidisciplinary SC Geology GA XC364 UT WOS:A1997XC36400002 ER PT J AU Sethian, JA AF Sethian, JA TI Tracking interfaces with level sets SO AMERICAN SCIENTIST LA English DT Article ID UNIFIED MODEL; LITHOGRAPHY; SIMULATIONS; DEPOSITION; ALGORITHMS; CURVATURE; FRONTS C1 LAWRENCE BERKELEY LAB,DEPT COMPUTAT & APPL MATH,BERKELEY,CA. RP Sethian, JA (reprint author), UNIV CALIF BERKELEY,DEPT MATH,BERKELEY,CA 94720, USA. NR 12 TC 16 Z9 16 U1 0 U2 5 PU SIGMA XI-SCI RES SOC PI RES TRIANGLE PK PA PO BOX 13975, RES TRIANGLE PK, NC 27709 SN 0003-0996 J9 AM SCI JI Am. Scientist PD MAY-JUN PY 1997 VL 85 IS 3 BP 254 EP 263 PG 10 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA WT577 UT WOS:A1997WT57700020 ER PT J AU Dixon, P Curtis, DB Musgrave, J Roensch, F Roach, J Rokop, D AF Dixon, P Curtis, DB Musgrave, J Roensch, F Roach, J Rokop, D TI Analysis of naturally produced technetium and plutonium in geologic materials SO ANALYTICAL CHEMISTRY LA English DT Article ID MASS-SPECTROMETRY; URANIUM AB In uncontaminated natural materials, plutonium and technetium exist exclusively as products (daughters) of nuclear reactions in which uranium is the principal reactant (parent), Under conditions of chemical stability over geologic periods of time, the relative abundances of daughter and parent elements are fixed by the rates of nuclear reactions and the decay of the daughter radionuclide, The state of this nuclear secular equilibrium condition is the primary basis of the geochemical study of these elements in nature, Thus, it is critical that nuclear parent and daughter abundances are measured in the same sample, We have developed a quantitative procedure for measuring subpicogram quanti ties of plutonium and technetium in gram quantities of geologic matrices such as uranium ores, The procedure takes advantage of the aggressive properties of sodium peroxide/hydroxide fusion to ensure complete dissolution and homogenization of complex materials, the precision provided by isotope dilution techniques, and the extreme sensitivity offered by thermal ionization mass spectrometry, Using this technique, a quantitative aliquot can be removed for uranium analysis by isotope dilution thermal ionization mass spectrometry or a spectrometry. Although the application of the procedure is unique, the analytical concepts may find more general application in studies of environmental contamination by nuclear materials, To assess the precision and accuracy of the analytical results, blanks and standards were analyzed routinely for a 1-year period to ensure quality control of our sample analyses, The average technetium blank is 5 +/- 4 fg (n = 8), and that for plutonium is 0.17 +/- 0,15 pg (n = 7), Thus, the detection limit for technetium (defined as 3 times the standard deviation of the average blank) is II fg, and that for plutonium is 0.44 pg, To assess the procedural precision, Canadian Reference Material BL-5 was analyzed routinely with samples, The results of seven replicate analyses for technetium in this standard reference material yield a technetium concentration of 59.0 fg/g, with a remarkably small standard deviation of 0,6 fg, 1,0% of the average value, The results of six replicate analyses for the concentration of plutonium in BL-5 give 1,012 pg/g with an equally small standard deviation of 0.016, 1,6% of the average value, No direct measure of accuracy can be done on the technetium or plutonium analyses, because no standard reference material exists for these elements, To help constrain the accuracy of our measurements, equilibrium technetium/uranium and plutonium/uranium abundances were calculated using the nuclear reaction code MCNP, For technetium, such calculations are relatively insensitive to variations in model parameters, and measurements fall within a 21%, high/low bias, For plutonium, the calculations are very sensitive to model parameters and hence inherently less precise, Indirectly spike and Isotope mix calibrations made from weighted quantities of certified isotopes (both technetium and plutoniun) can be used to determine the bias of the measurement system for these elements, These calibrations show that the measurement system is biased by no more than +/-1.5%. RP Dixon, P (reprint author), LOS ALAMOS NATL LAB,DIV ISOTOPE & NUCL CHEM,MAIL STOP J-514,LOS ALAMOS,NM 87545, USA. NR 17 TC 24 Z9 24 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD MAY 1 PY 1997 VL 69 IS 9 BP 1692 EP 1699 DI 10.1021/ac961159q PG 8 WC Chemistry, Analytical SC Chemistry GA WX128 UT WOS:A1997WX12800009 PM 21639292 ER PT J AU Knapp, FF McPherson, DW Luo, H Zeeburg, B AF Knapp, FF McPherson, DW Luo, H Zeeburg, B TI Radiolabeled ligands for imaging the muscarinic-cholinergic receptors of the heart and brain SO ANTICANCER RESEARCH LA English DT Article DE muscarinic ligands; IQNB; IQNP ID EMISSION COMPUTED-TOMOGRAPHY; IODINE-125-LABELED 1-AZABICYCLO<2.2.2>OCT-3-YL ALPHA-HYDROXY-ALPHA-(1-IODO-1-PRO; ACETYLCHOLINE-RECEPTORS; ALZHEIMERS-DISEASE; BINDING; INVIVO; SUBTYPES; BIODISTRIBUTION; SELECTIVITY; DEMENTIA AB Interest in the potential use of cerebral SPECT and PET imaging for determination of the density and activity of muscarinic-cholinergic receptors (mAChR) has been stimulated by the changes in these receptors which occur in many neurological diseases. In addition, the important involvement of mAChR in modulating negative inotropic cardiac activity suggests that such receptor ligands may have important applications in evaluation of changes which may occur in cardiac disease. In this paper, the properties of several key muscarinic receptor ligands being developed or which have been used for clinical SPECT and PET are discussed. In addition the ORNL development of the new iodinated IQNP ligand based on IQNB and the results of in vivo biodistribution studies in rats, in vitro competitive binding studies and ex vivo autoradiographic experiments are described. The we of radioiodinated IQNP may offer several advantages in comparison to IQNB because of its easy and high yield preparation and high brain uptake and the potential usefulness of the ''partial'' subtype selective IQNP isomers. We also describe the development of new IQNP-type analogues which offer the opportunity for radiolabeling with positron-emitting radioisotopes (carbon-11, fluorine-18 and bromine-76) for potential use with PET. C1 GEORGE WASHINGTON UNIV,MED CTR,RADIOPHARMACEUT CHEM SECT NUCL MED,WASHINGTON,DC 20037. RP Knapp, FF (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,NUCL MED GRP,OAK RIDGE,TN 37831, USA. NR 63 TC 5 Z9 6 U1 0 U2 0 PU INT INST ANTICANCER RESEARCH PI ATHENS PA EDITORIAL OFFICE 1ST KM KAPANDNTIOU-KALAMOU RD KAPANDRITI, POB 22, ATHENS 19014, GREECE SN 0250-7005 J9 ANTICANCER RES JI Anticancer Res. PD MAY-JUN PY 1997 VL 17 IS 3B BP 1559 EP 1572 PG 14 WC Oncology SC Oncology GA XB417 UT WOS:A1997XB41700001 PM 9179195 ER PT J AU Knapp, FF Beets, AL Guhlke, S Zamora, PO Bender, H Palmedo, H Biersack, HJ AF Knapp, FF Beets, AL Guhlke, S Zamora, PO Bender, H Palmedo, H Biersack, HJ TI Availability of rhenium-188 from the alumina-based tungsten-188/rhenium-188 generator for preparation of rhenium-188-labeled radiopharmaceuticals for cancer treatment SO ANTICANCER RESEARCH LA English DT Article DE rhenium-188; radiopharmaceuticals; cancer treatment ID RE-188 AB Rhenium-188 (beta- = 2.2 MeV; gamma- = 155 keV; T-1/2 16.9 hours) is an attractive therapeutic radioisotope which is produced from decay of the reactor produced tungsten-188 parent (T1/2 69 days) and thus conveniently obtained on demand by elution fi om the alumina-based tungsten-188 /rhenium-188 generator system. The rhenium-188 is obtained as sodium perrhenate by elution of the generator with 0.9% saline. The post elution use of disposable tandem, ion-exchange columns is a simple method for the concentration of rhenium-188 saline solutions with specific volumes > 500 mCi/ml. This method can also extend the useful shelf-life of the generator, which can be as long as one year. The long useful shelf-life of the generator is expected to provide rhenium-188 at very reasonable costs for routine preparation of a variety of radiopharmaceuticals for the treatment of a variety of cancers,including breast cancer. We are evaluating two types of Re-188-labeled agents under investigation which have potential for the treatment of breast cancer. Rhenium-188-labeled hydroxyethylidenedophosphonate (HEDP) and Re-188-dimercaptosuccinic acid (DMSA) are being applied for palliative treatment of pain associated with skeletal metastases, and the Re-188-RC-160 somatostatin analogue [cyclic NH2-(D)-Phe-Cys- Try-(D)-Trp-Lys-Val-Cys-Trp-NH2] for somatostatin-receptor-positive tumors. The results of initial clinical studies with the two bone pain agents demonstrate good targeting to skeletal metastases, and use of Re-188-HEDP has resulted in. pain palliation with minimal bone marrow suppression in the initial patient studies. While these initial studies have been conducted in patients with prostate cancer; similar results are expected in planned studies in breast cancer patients. In animal studies, Re-188-RC-160 has been successfully used for the local/regional treatment of experimental breast cancer and other cancers. Re-188-RC-160 binds to somatostatin-receptor- positive cells both in vitro and in vivo, including breast cancer cells (ZR-75-1 breast carcinoma and NCI-H69 human small cell ling carcinoma), but not to binding-negative cells (Raji, Burkitt's lymphoma). A structurally similar Re-188-cyclic peptide with different binding specificity (CTOP [cyclic NH2-(D)-Phe-Cys-Try-(D)-Trp-Orn-Thr-Pen-Thr-ol]; art opiate-receptor antagonost) did not bind to target cells. Both gentisic acid and ascorbic acid are present in the Re-188-HEDP and Re-188-RC-160 formulations and have been found to also significantly reduce radiolytic degradation of the somatostatin peptide analogues, and may have general application in the stabilization of Re-188-labled radiopharmaceuticals. C1 UNIV BONN,CLIN NUCL MED,D-5300 BONN,GERMANY. RP Knapp, FF (reprint author), OAK RIDGE NATL LAB,NUCL MED GRP,DIV LIFE SCI,NUCL MED PROGRAM,POB 2008,BLDG 4501,MAIL STOP 6229,OAK RIDGE,TN 37830, USA. NR 38 TC 137 Z9 144 U1 0 U2 6 PU INT INST ANTICANCER RESEARCH PI ATHENS PA EDITORIAL OFFICE 1ST KM KAPANDNTIOU-KALAMOU RD KAPANDRITI, POB 22, ATHENS 19014, GREECE SN 0250-7005 J9 ANTICANCER RES JI Anticancer Res. PD MAY-JUN PY 1997 VL 17 IS 3B BP 1783 EP 1795 PG 13 WC Oncology SC Oncology GA XB417 UT WOS:A1997XB41700041 PM 9179235 ER PT J AU Zamora, PO Bender, H Gulhke, S Marek, MJ Knapp, FF Rhodes, BA Biersack, HJ AF Zamora, PO Bender, H Gulhke, S Marek, MJ Knapp, FF Rhodes, BA Biersack, HJ TI Pre-clinical experience with Re-188-RC-160, a radiolabeled somatostatin analog for use in peptide-targeted radiotherapy SO ANTICANCER RESEARCH LA English DT Article DE rhenium; RC-160; radiotherapy; small cell lung carcinoma; breast carcinoma ID ANTIBODY-GUIDED IRRADIATION; NUDE-MICE; RECEPTOR SCINTIGRAPHY; MONOCLONAL-ANTIBODIES; BIOLOGICAL-ACTIVITY; ANTAGONIST RC-3095; CANCER; RC-160; GROWTH; OCTREOTIDE AB The clinical potential of radiolabeled peptides such as octreotide and VIP has been widely established for tumor localization. Radiotherapy based on the tumor binding potential of the peptides and the radiotoxic effects of beta- or alpha-emitting radionuclides is an extension of such applications. Rhenium-188 (T-1/2 16.9hr, beta(max)(-) 2.1 MeV) coupled to the analogue RC-160 has been used to establish the feasibility of treating tumors with radiolabeled peptides, and our experience with this approach is summarized. In three different experimental Rimer models (human prostate, mammary gland and small cell lung carcinomas) in nude mice, treatment resulted in significant reduction or elimination of tumor burden. Two routes of administration were used: intra-lesional injection (prostate carcinoma) and intra-cavity injection (mammary and SCLC). Re-188-labeled negative control peptides bound to tumor- cells to a low extent and did not exhibit therapeutic benefit. RC-160 by itself did not result in therapeutic benefit. Tumors which did not bind Re-188-RC-160 did not evidence a therapeutic benefit. Uncoupled Re-188 (control) was rapidly excreted via the urinary bladder and did not accumulate in either tumors or normal tissues even following direct injection. Instant radiolabeling kits containing 200 mu g of RC-16O were labeled with <3000 MBq of Re-188 in 30 minutes with no need for subsequent purification. These studies establish the conceptual feasibility of targeted radiotherapy based on the local or regional administration of radiolabeled peptides. 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 33 TC 25 Z9 27 U1 0 U2 0 PU INT INST ANTICANCER RESEARCH PI ATHENS PA EDITORIAL OFFICE 1ST KM KAPANDNTIOU-KALAMOU RD KAPANDRITI, POB 22, ATHENS 19014, GREECE SN 0250-7005 J9 ANTICANCER RES JI Anticancer Res. PD MAY-JUN PY 1997 VL 17 IS 3B BP 1803 EP 1808 PG 6 WC Oncology SC Oncology GA XB417 UT WOS:A1997XB41700043 PM 9179237 ER PT J AU Li, J Srivastav, RP AF Li, J Srivastav, RP TI Computing the singular behavior of solutions of Cauchy singular integral equations with variable coefficients SO APPLIED MATHEMATICS LETTERS LA English DT Article DE singular integral equation; fundamental solution; nonlinear equations AB A numerical technique to determine the singular behavior of the solution of Cauchy singular integral equations (CSIE) with variable coefficients is proposed. The fundamental solution, which is a solution of the corresponding homogeneous equation, is constructed by a quadrature-collocation scheme. This leads to a system of nonlinear equations to approximate the exponents of singularity. Newton's method has been found to yield a useful approximation to these exponents. Once we have numerically obtained the weight function which determines the behavior of the solution of Cauchy singular integral equation, it can be used to solve a variety of nonhomogeneous CSIE with variable coefficients. C1 SUNY STONY BROOK,DEPT APPL MATH & STAT,STONY BROOK,NY 11794. RP Li, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0893-9659 J9 APPL MATH LETT JI Appl. Math. Lett. PD MAY PY 1997 VL 10 IS 3 BP 57 EP 62 DI 10.1016/S0893-9659(97)00035-9 PG 6 WC Mathematics, Applied SC Mathematics GA WZ252 UT WOS:A1997WZ25200012 ER PT J AU Fantone, SD AF Fantone, SD TI Improving fiber-optic laser beam delivery by incorporating GRADIUM optics SO APPLIED OPTICS LA English DT Article DE axial-gradient lenses; GRADIUM; Nd:YAG; BK7; optical fibers; beam diagnostics AB The performance of a fiber-optic laser beam delivery system strongly depends on the fiber and the optics used to image the fiber face on the workpiece. We have compared off-the-shelf homogenous (BK7) and GRADIUM (axial-gradient) singlets to determine what improvement the GRADIUM offers in practice to the typical laser user. The realized benefit for this application, although significant, is much smaller than would be realized by a conventional imaging application. The figure of merit for laser-based materials processing is the 86% energy-enclosure radius, which is not directly supported by commercial ray-tracing software. Therefore empirical rules of thumb are presented to understand when GRADIUM (or any other well-corrected optics) will yield meaningful improvements to the beam delivery system. (C) 1997 Optical Society of America. C1 ARGONNE NATL LAB,TECHNOL DEV DIV,LASER APPLICAT LAB,ARGONNE,IL 60439. NR 12 TC 2 Z9 2 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 MAY 1 PY 1997 VL 36 IS 13 BP 2763 EP 2769 PG 7 WC Optics SC Optics GA WX242 UT WOS:A1997WX24200003 ER PT J AU Tuminello, PS Arakawa, ET Khare, BN Wrobel, JM Querry, MR Milham, ME AF Tuminello, PS Arakawa, ET Khare, BN Wrobel, JM Querry, MR Milham, ME TI Optical properties of Bacillus subtilis spores from 0.2 to 2.5 mu m SO APPLIED OPTICS LA English DT Article DE optical constants; bacterial spores; index of refraction; extinction coefficient; thin films; suspension ID STEADY-STATE; DECAY CHARACTERISTICS; INTERSTELLAR GRAINS; FLUORESCENCE; ULTRAVIOLET; PARTICLES; BACTERIA; SPECTRA AB Ne have used spectral reflectance and transmittance measurements combined with Kramers-Kronig analyses to obtain the red (n) and imaginary (k) parts of the complex refractive index, N = n + ik, of Bacillus subtilis spores over a wavelength interval from 0.2 to 2.5 mu m. Samples were in the form of thin solid films, pressed pellets, and suspensions in water and glycerol. The optical constants of spores suspended in water were found to differ from those of spores suspended in glycerol. In addition, spores previously exposed to water in earlier experiments and subsequently dried exhibited different optical constants from spores that had not been exposed to water. (C) 1997 Optical Society of America. C1 CORNELL UNIV,PLANETARY STUDIES LAB,ITHACA,NY 14853. UNIV MISSOURI,DEPT PHYS,KANSAS CITY,MO 64110. USA,MCCOM,EDGEWOOD RES DEV & ENGN CTR,ABERDEEN PROVING GROUND,MD 21010. RP Tuminello, PS (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,OAK RIDGE,TN 37831, USA. NR 23 TC 60 Z9 63 U1 1 U2 6 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD MAY 1 PY 1997 VL 36 IS 13 BP 2818 EP 2824 DI 10.1364/AO.36.002818 PG 7 WC Optics SC Optics GA WX242 UT WOS:A1997WX24200014 PM 18253278 ER PT J AU Stallard, BR AF Stallard, BR TI Near-IR versus mid-IR: Separability of three classes of organic compounds SO APPLIED SPECTROSCOPY LA English DT Article DE near-IR spectroscopy; IR spectroscopy; chemometrics; class separation AB Recently there has been a surge of interest in spectroscopic sensors operating in the near-IR, although it is recognized that the mid-IR contains more spectral information. The general question addressed in this paper is, How much specificity is lost in choosing the near-IR over the mid-IR for sensor applications? The example considered is the separability among three classes of organic compounds: alkanes, alcohols, and ketones/aldehydes. We use spectra from two sources: the Hummel polymer library (mid-IR) and the library of Buback and Vogele (near-IR). This is the first paper on class separability to make use of this new near-IR library, available in digital form only since July 1995. Five spectral regions are considered: region 5, 10,500 to 6300 cm(-1); region 4, 7200 to 5200 cm(-1); region 3, 5500 to 3800 cm(-1) ; region 2, 3900 to 2500 cm(-1); and region 1, 2500 to 500 cm(-1). Class separability is explored both qualitatively and quantitatively with the use of principal component scatter plots, linear discriminant analysis, Bhattacharyya distances, and other methods. We find that the separability is greatest in region 1 and least in region 2, with the three near-IR regions being intermediate. Furthermore, we find that, in the near-IR, there is sufficient class separability to ensure that organic compounds of one class can be determined in the midst of interference from the other classes. RP Stallard, BR (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 15 TC 13 Z9 13 U1 0 U2 2 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 201B BROADWAY ST, FREDERICK, MD 21701 SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAY PY 1997 VL 51 IS 5 BP 625 EP 630 DI 10.1366/0003702971941025 PG 6 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA XB789 UT WOS:A1997XB78900005 ER PT J AU Webb, RL Dickinson, JT Exarhos, GJ AF Webb, RL Dickinson, JT Exarhos, GJ TI Characterization of particulates accompanying laser ablation of NaNO3 SO APPLIED SPECTROSCOPY LA English DT Article DE laser ablation; inductively coupled plasma-optical emission spectroscopy (ICP-OES); inductively coupled plasma-mass spectroscopy (ICP-MS); particulates; aggregation; laser plume; electrostatic charge; plume chemistry ID GAP SINGLE-CRYSTALS; DEPOSITION; RADIATION; EMISSION AB We present observations of submicrometer- to micrometer-sized particles generated by high-fluence (greater than or equal to 10 J/cm(2)) 248-nm laser ablation of single-crystal NaNO3, in vacuum and at atmospheric pressure, Small particles (50-200 nm in diameter) are ejected by hydrodynamic sputtering, Larger particles (1-20 mu m in diameter) rare produced by cavitation and spallation in the melt, Many particles formed in air carry electric charge, with roughly equal numbers of positively and negatively charged particles, The particle composition is consistent with substantial nitrate decomposition, The implications of these observations with respect to laser-based chemical analysis are discussed. C1 WASHINGTON STATE UNIV, DEPT PHYS, PULLMAN, WA 99164 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. NR 37 TC 31 Z9 31 U1 1 U2 5 PU SOC APPLIED SPECTROSCOPY PI FREDERICK PA 5320 SPECTRUM DRIVE SUITE C, FREDERICK, MD 21703 USA SN 0003-7028 J9 APPL SPECTROSC JI Appl. Spectrosc. PD MAY PY 1997 VL 51 IS 5 BP 707 EP 717 DI 10.1366/0003702971940855 PG 11 WC Instruments & Instrumentation; Spectroscopy SC Instruments & Instrumentation; Spectroscopy GA XB789 UT WOS:A1997XB78900016 ER PT J AU Howell, RH Cowan, TE Hartley, J Sterne, P Brown, B AF Howell, RH Cowan, TE Hartley, J Sterne, P Brown, B TI Positron beam lifetime spectroscopy of atomic scale defect distributions in bulk and microscopic volumes SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 7th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces CY JUN 02-07, 1996 CL UNTERAGERI, SWITZERLAND ID MICROBEAM AB We are developing a defect analysis capability based on two positron beam lifetime spectrometers: the first is based on a 3 MeV electrostatic accelerator and the second on our high current linac beam. The high energy beam Lifetime spectrometer is operational and positron lifetime analysis is performed with a 3 MeV positron beam on thick sample specimens. It is being used for bulk sample analysis and analysis of samples encapsulated in controlled environments for in situ measurements. A second, low energy, microscopically focused, pulsed positron beam for defect analysis by positron lifetime spectroscopy is under development at the LLNL high current positron source. This beam will enable defect-specific, 3-dimensional maps of defect concentration with sub-micron location resolution. When coupled with first principles calculations of defect specific positron lifetimes it will enable new levels of defect concentration mapping and defect identification. C1 MT HOLYOKE COLL,HADLEY,MA 01003. RP Howell, RH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. RI Cowan, Thomas/A-8713-2011 OI Cowan, Thomas/0000-0002-5845-000X NR 7 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY PY 1997 VL 116 BP 7 EP 12 DI 10.1016/S0169-4332(96)00965-8 PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA XB403 UT WOS:A1997XB40300003 ER PT J AU Petkov, MP Lynn, KG Roellig, LO Troev, TD AF Petkov, MP Lynn, KG Roellig, LO Troev, TD TI An investigation of positrons interacting with solid argon, krypton and xenon SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 7th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces CY JUN 02-07, 1996 CL UNTERAGERI, SWITZERLAND DE positron beam; moderators; solid rare gases; impurity ID SLOW POSITRONS; MODERATOR AB With this article we intend to shed some light on all the important characteristics of the up-to-date most efficient positron moderators, the rare gas solids. We stress on the importance of the impurities in the performance of the solid rare gas moderators. The impurity factor is linked with the crystalline changes to explain the effect of annealing, and we demonstrate the role of impurities in the endurance. Significant increase in the low energy positron yield is observed after repeated anneals. The positron energy distributions from Ar, Kr, and Xe moderators are measured to be about 2 eV (FWHM). C1 BROOKHAVEN NATL LAB,DEPT ENERGY,UPTON,NY 11973. CUNY CITY COLL,NEW YORK,NY 10031. BULGARIAN ACAD SCI,INST NUCL RES & NUCL ENERGY,BU-1184 SOFIA,BULGARIA. NR 11 TC 5 Z9 5 U1 1 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY PY 1997 VL 116 BP 13 EP 18 DI 10.1016/S0169-4332(96)00966-X PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA XB403 UT WOS:A1997XB40300004 ER PT J AU Xu, J Suzuki, R Hulett, LD Lewis, TA AF Xu, J Suzuki, R Hulett, LD Lewis, TA TI Production of slow positron bunches at ORELA and their applications SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 7th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces CY JUN 02-07, 1996 CL UNTERAGERI, SWITZERLAND ID PULSING SYSTEM; LIFETIME; BEAM AB Two methods are under study for bunching 15 ns pulses of slow positrons produced by the Oak Ridge electron linear accelerator (ORELA). The first method involves the application of a time-dependent potential to a remoderating foil during the time positrons an being emitted from it. Lifetime spectra of polymer films have been collected with a resolution of 500 ps. The positron flux into the specimen during the pulse was about 3.9 x 10(11)/s. A molybdenum moderator foil was used with an ORELA power of 3 kW. The quadratic potential bunching technique is also being considered. In this method a voltage is applied to a string of lenses, such that the potential experienced by positrons contained within the lenses varies as the square of the distance from a point that is defined at ground potential. Calculations indicate that a time resolution of about 200 ps can be achieved with this method. C1 ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN. RP Xu, J (reprint author), OAK RIDGE NATL LAB,POB 2008,MS 6142,OAK RIDGE,TN 37831, USA. NR 7 TC 1 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY PY 1997 VL 116 BP 34 EP 38 DI 10.1016/S0169-4332(96)00970-1 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA XB403 UT WOS:A1997XB40300008 ER PT J AU White, MM Lessner, ES AF White, MM Lessner, ES TI The advanced photon source (APS) linear accelerator as a source of slow positrons SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 7th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces CY JUN 02-07, 1996 CL UNTERAGERI, SWITZERLAND AB The advanced photon source [1] linear accelerator (linac) system consists of a 200 MeV, 2856 MHz S-band electron linac, a 2 radiation-length thick tungsten target for positron production, and a 450 MeV positron linac [2]. The linac is briefly described, and some possibilities for its use as a slow positron source are discussed. RP White, MM (reprint author), ARGONNE NATL LAB,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 7 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY PY 1997 VL 116 BP 87 EP 90 DI 10.1016/S0169-4332(96)01034-3 PG 4 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA XB403 UT WOS:A1997XB40300019 ER PT J AU Ghosh, VJ Alatalo, M AsokaKumar, P Lynn, KG Kruseman, AC AF Ghosh, VJ Alatalo, M AsokaKumar, P Lynn, KG Kruseman, AC TI The momentum distribution of annihilating positron-electron pairs in aluminum SO APPLIED SURFACE SCIENCE LA English DT Article; Proceedings Paper CT 7th International Workshop on Slow-Positron Beam Techniques for Solids and Surfaces CY JUN 02-07, 1996 CL UNTERAGERI, SWITZERLAND DE momentum distribution; positron states; positron annihilation; lifetime; vacancy ID SOLIDS; SURFACES AB Experimental and theoretical results for the momentum distribution of the positron-electron pairs in defect-free bull; Al and Al containing vacancies are presented. The experimental data was obtained using a two-Ge-detector coincidence measurement of the Doppler broadening of the annihilation radiation. This setup enables an accurate measurement of the high-momentum part of the spectrum, thereby making it possible to compare experimental and theoretical results over a wider momentum range. Various approximations of the localized positron wave function (in the presence of an ideal monovacancy) an discussed. C1 DELFT UNIV TECHNOL,INTERFAC REACTOR INST,NL-2629 JB DELFT,NETHERLANDS. RP Ghosh, VJ (reprint author), BROOKHAVEN NATL LAB,UPTON,NY 11973, USA. NR 15 TC 11 Z9 11 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY PY 1997 VL 116 BP 278 EP 282 DI 10.1016/S0169-4332(96)01069-0 PG 5 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA XB403 UT WOS:A1997XB40300054 ER PT J AU Hughes, RC Bastasz, R Ellis, WP AF Hughes, RC Bastasz, R Ellis, WP TI Hydrogen sensing in vacuum systems with catalytic field plate MNOS capacitors SO APPLIED SURFACE SCIENCE LA English DT Article ID SENSITIVE MOS-STRUCTURES; ADSORPTION; ABSORPTION; SENSORS; SILICON AB The rate of response of catalytic field plate MNOS capacitors to steps in hydrogen partial pressure in a ultra high vacuum pressure. A combination of light sputter cleaning and elevated sensor temperature produces a sensor response fast enough to be of interest in the monitoring of hydrogen partial pressures in a processing chamber. C1 SANDIA NATL LABS,LIVERMORE,CA. LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Hughes, RC (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 9 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-4332 J9 APPL SURF SCI JI Appl. Surf. Sci. PD MAY PY 1997 VL 115 IS 1 BP 74 EP 79 DI 10.1016/S0169-4332(96)00846-X PG 6 WC Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Chemistry; Materials Science; Physics GA WX178 UT WOS:A1997WX17800010 ER PT J AU Hill, WR Napolitano, GE AF Hill, WR Napolitano, GE TI PCB congener accumulation by periphyton, herbivores, and omnivores SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID POLYCHLORINATED BIPHENYL CONGENERS; STREAM PERIPHYTON; LAKE; BIOACCUMULATION; SEDIMENTS; LIGHT; PHYTOPLANKTON; METABOLISM; OYSTERS; WATER AB The concentrations of 20 polychlorinated biphenyl (PCB) congeners were measured in periphyton, herbivorous fish (stoneroller minnows, Campostoma anomalum), and omnivorous fish (striped shiners, Luxilus chrysocephalus) in an industrially contaminated stream and a reference stream in eastern Tennessee. The sum of the concentrations of the 20 congeners, normalized by dry mass, was one to two orders of magnitude higher in stonerollers and shiners than in periphyton. Normalizing PCB concentrations by lipid mass reduced concentration differences between periphyton and stonerollers, ut PCBs per unit lipid in stonerollers were still 50-350% higher than those in periphyton. Shiners had significantly higher lipid-specific PCB concentrations than did stonerollers, so a trophic hierarchy of primary producer < herbivore < omnivore was evident in lipid-specific PCB concentrations. Differences in lipid type, exposure duration, and exposure sources may account for the trophic-level differences in total PCBs. Congener profiles were roughly similar in periphyton, stonerollers, and shiners: five congeners (IUPAC numbers 101, 110, 138, 153, and 180) constituted > 60% of the total mass of PCBs analyzed in all three trophic levels. However, stoneroller and shiner tissue was enriched in congeners 153, 118, and 187 relative to periphyton; congeners 153 and 187 are resistant to metabolic breakdown by monooxygenases found in fish liver. Principal component analysis of congener percentages separated periphyton from fish and distinguished between sampling locations. RP Hill, WR (reprint author), OAK RIDGE NATL LAB, DIV ENVIRONM SCI, POB 2008, OAK RIDGE, TN 37831 USA. NR 33 TC 17 Z9 17 U1 0 U2 7 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-4341 EI 1432-0703 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD MAY PY 1997 VL 32 IS 4 BP 449 EP 455 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA XG447 UT WOS:A1997XG44700019 PM 9175515 ER PT J AU Teng, BB Ishida, B Forte, TM Blumenthal, S Song, LZ Gotto, AM Chan, L AF Teng, BB Ishida, B Forte, TM Blumenthal, S Song, LZ Gotto, AM Chan, L TI Effective lowering of plasma, LDL, and esterified cholesterol in LDL receptor knockout mice by adenovirus-mediated gene delivery of ApoB mRNA editing enzyme (Apobec1) SO ARTERIOSCLEROSIS THROMBOSIS AND VASCULAR BIOLOGY LA English DT Article DE gene therapy; LDL receptor-deficient mouse; apoB mRNA editing; hypercholesterolemia; lipoproteins ID B MESSENGER-RNA; LOW-DENSITY LIPOPROTEINS; APOLIPOPROTEIN-B; RAT-LIVER; ENDOPLASMIC-RETICULUM; CYTIDINE DEAMINASE; CATALYTIC SUBUNIT; PROTEIN; SECRETION; HYPERCHOLESTEROLEMIA AB Adenovirus-mediated gene delivery of apolipoprotein (apo)B mRNA editing enzyme (AvApobec1) was used to study the effect of apoB mRNA editing on apoB production in homozygous LDL receptor-deficient (LDLR-/-) mice. Intravenous injection of AvApobec1 into these mice resulted in a >80% decrease in plasma apoB-100 with a concomitant increase in plasma apoB-48 level. The plasma apoE level also increased. In all cases, total plasma apoB (apoB-100 + apoB-48) decreased by 60% at day 5 and remained approximate to 40% lower in AvApobec1-treated compared with control vector Av1LacZ4-treated animals at day 12. On day 12, total plasma cholesterol decreased by 29% in male mice and 18% in female mice that were transduced with AvApobec1. This was reflected in a reduction in apoB-containing lipoprotein cholesterol, which decreased by 34% and 27% in male and female mice, respectively. Apobec1 gene transfer also decreased the cholesteryl ester contents in the LDL fraction, which were 16%, 22%, and 22% in female and 20%, 20%, and 15% in male animals on days 5, 7, and 12, respectively, compared with Av1LacZ controls with 29%, 32%, and 33%, respectively, in female and 29%, 38%, and 36%, respectively, in male animals. Nondenaturing gradient gel electrophoresis indicated almost complete elimination of LDL particles of 29, 27, and 25 nm at days 7 and 12. We conclude that in the absence of a functioning LDL receptor, hepatic overexpression of Apobec1 is highly efficient in lowering plasma apoB-100 levels, leading to the almost complete elimination of LDL particles and a reduction in LDL cholesterol and cholesteryl ester content. C1 UNIV CALIF SAN FRANCISCO, DEPT MED, SAN FRANCISCO, CA USA. LAWRENCE BERKELEY LAB, DIV LIFE SCI, BERKELEY, CA USA. RP Teng, BB (reprint author), BAYLOR COLL MED, DEPT MED, SECT ATHEROSCLEROSIS & LIPOPROT RES, 1 BAYLOR PLAZA, HOUSTON, TX 77030 USA. FU NHLBI NIH HHS [HL-16512, HL-18574, HL-53441] NR 32 TC 23 Z9 25 U1 0 U2 1 PU AMER HEART ASSOC PI DALLAS PA 7272 GREENVILLE AVENUE, DALLAS, TX 75231-4596 SN 1079-5642 J9 ARTERIOSCL THROM VAS JI Arterioscler. Thromb. Vasc. Biol. PD MAY PY 1997 VL 17 IS 5 BP 889 EP 897 PG 9 WC Hematology; Peripheral Vascular Disease SC Hematology; Cardiovascular System & Cardiology GA WZ649 UT WOS:A1997WZ64900012 PM 9157952 ER PT J AU Schaab, C Voskresensky, D Sedrakian, AD Weber, F Weigel, MK AF Schaab, C Voskresensky, D Sedrakian, AD Weber, F Weigel, MK TI Impact of medium effects on the cooling of non-superfluid and superfluid neutron stars SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE stars, neutron; stars, evolution; dense matter; X-rays, stars ID LIQUID-METAL PHASE; PULSED X-RAYS; NUCLEAR-MATTER; THERMAL EVOLUTION; DENSE MATTER; CONDUCTIVITIES; POLARIZATION; TEMPERATURE; EQUATION; STATE AB Neutrino emission from the dense hadronic component in neutron stars is subject to strong modifications due to collective effects in the nuclear medium. We implement new estimates of the neutrino emissivities of two processes operating in the nuclear medium into numerical cooling simulations of neutron stars. The first process is the modified Urea process, for which the softening of the pion exchange mode and other polarization effects as well as the neutrino emission arising from the intermediate reaction states are taken into account. The second process concerns neutrino emission through superfluid pair breaking and formation processes. It is found that the medium effects on the emissivity of the modified Urea process result in a strong density dependence, which gives a smooth crossover from the standard to the nonstandard cooling scenario for increasing star masses. For superfluid stars, the superfluid pair breaking and formation processes accelerate mildly both the standard and the nonstandard cooling scenario. This leads to a good agreement between the theoretical cooling tracks and the rather low temperatures observed for objects like PSRs 0833-45 (Vela), 0656+14, and 0630+18 (Geminga). The robustness of our findings against variations in both the underlying equation of state of baryonic matter and the used fast cooling processes is demonstrated. Hence we conclude that the two recalculated neutrino emissivities studied here enable one to reproduce theoretically most of the observed pulsar temperatures by varying the masses of neutron star models. C1 GESELL SCHWERIONENFORSCH MBH, D-64220 DARMSTADT, GERMANY. MOSCOW INST PHYS & ENGN, MOSCOW 115409, RUSSIA. UNIV ROSTOCK, MAX PLANCK SOC, RES UNIT THEORET MANY PARTICLE PHYS, D-18051 ROSTOCK, GERMANY. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, DIV NUCL SCI, BERKELEY, CA 94720 USA. RP Schaab, C (reprint author), UNIV MUNICH, INST THEORET PHYS, THERESIENSTR 37-III, D-80333 MUNICH, GERMANY. RI Schaab, Christoph/C-6098-2008 NR 88 TC 63 Z9 63 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 EI 1432-0746 J9 ASTRON ASTROPHYS JI Astron. Astrophys. PD MAY PY 1997 VL 321 IS 2 BP 591 EP 604 PG 14 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XB498 UT WOS:A1997XB49800032 ER PT J AU DeKeyser, J Roth, M Tsurutani, BT Ho, CM Phillips, JL AF DeKeyser, J Roth, M Tsurutani, BT Ho, CM Phillips, JL TI Solar wind velocity jumps across tangential discontinuities: Ulysses observations and kinetic interpretation SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE magnetic fields; plasmas; solar wind; interplanetary medium ID MAGNETOPAUSE CURRENT LAYER; AU AB Some tangential discontinuities (TDs) observed by the ULYSSES spacecraft interface solar wind regions that differ only in their bulk velocity and magnetic field orientation; composition, density, temperature and magnetic field intensity are essentially the same in both regions. The relation between the plasma velocity jump across the TD and the magnetic field is investigated through the analysis and simulation of equilibrium plane TD configurations. These theoretical results are compared with ULYSSES observations. It is concluded that (a) the theoretically predicted magnetic field profile agrees with the morphology of the observed profile, (b) solar wind transitions are essentially of mixed type, i.e. both ion and electron velocity distribution functions are non-Maxwellian inside the transition layer, (c) there are constraints on the orientation and magnitude of the velocity jump that can be supported across a single transition, (d) large magnetic field rotations correspond io wide transition layers, and (e) in addition to density and temperature inhomogeneities, variations in the bulk velocity are a major reason for the solar wind plasma to set up current-carrying boundary layers. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP DeKeyser, J (reprint author), BELGIAN INST SPACE AERON, RINGLAAN 3, B-1180 BRUSSELS, BELGIUM. NR 26 TC 7 Z9 7 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 MAY PY 1997 VL 321 IS 3 BP 945 EP 959 PG 15 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA XB660 UT WOS:A1997XB66000032 ER PT J AU Habib, SF Kandrup, HE Mahon, ME AF Habib, SF Kandrup, HE Mahon, ME TI Chaos and noise in galactic potentials SO ASTROPHYSICAL JOURNAL LA English DT Article DE celestial mechanics, stellar dynamics; galaxies, evolution; galaxies, kinematics and dynamics; galaxies, structure ID 3-PARTICLE TODA LATTICE; ELLIPTICAL GALAXIES; BARRED GALAXIES; HAMILTONIAN-SYSTEMS; DYNAMICS; STOCHASTICITY; RELAXATION; TRANSPORT; BEHAVIOR; ORBITS AB This paper summarizes an investigation of the effects of weak friction and noise in time-independent, nonintegrable two-dimensional potentials that admit both regular and stochastic orbits. The aim is to understand the qualitative effects of internal and external irregularities associated with discreteness effects or couplings to an external environment, which stars in any real galaxy must experience. It is found that these irregularities can be important already on timescales much shorter than the natural relaxation timescale t(R) associated with two-body relaxation. In particular, for stochastic orbits friction and noise result in an exponential divergence from the unperturbed Hamiltonian trajectory, at a rate set by the value of the local Lyapunov exponent, which persists even for relatively large deviations from the unperturbed trajectory. Friction and noise can also have significant effects on the statistical properties of ensembles of stochastic orbits. Stochastic orbits may be divided into two classes, confined or sticky stochastic orbits which are trapped near islands of regularity, and unconfined or filling stochastic orbits that travel unimpeded throughout a stochastic sea. In the absence of friction and noise, transitions between confined and filling stochastic orbits are very slow. However, even very weak friction and noise can drastically accelerate such transitions, leading to an approach toward a statistical equilibrium on timescales much less than t(R). In the two-dimensional models studied in this paper, there are cases for which t(R) exceeds 10(6) crossing times where friction and noise can induce transitions for more than half the orbits within 100 crossing times, this corresponding in galaxies to a Hubble time t(H). Implications for galactic dynamics are discussed. C1 UNIV FLORIDA,DEPT ASTRON,GAINESVILLE,FL 32611. UNIV FLORIDA,INST FUNDAMENTAL THEORY,GAINESVILLE,FL 32611. UNIV FLORIDA,DEPT PHYS,GAINESVILLE,FL 32611. RP Habib, SF (reprint author), LOS ALAMOS NATL LAB,T-6,LOS ALAMOS,NM 87545, USA. NR 56 TC 35 Z9 37 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 MAY 1 PY 1997 VL 480 IS 1 BP 155 EP & DI 10.1086/303935 PN 1 PG 13 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WW282 UT WOS:A1997WW28200013 ER PT J AU Provencal, JL Winget, DE Nather, RE Robinson, EL Clemens, JC Bradley, PA Claver, CF Kleinman, SJ Grauer, AD Hine, BP Ferrario, L ODonoghue, D Warner, B Vauclair, G Chevreton, M Kepler, SO Wood, MA Henry, GW AF Provencal, JL Winget, DE Nather, RE Robinson, EL Clemens, JC Bradley, PA Claver, CF Kleinman, SJ Grauer, AD Hine, BP Ferrario, L ODonoghue, D Warner, B Vauclair, G Chevreton, M Kepler, SO Wood, MA Henry, GW TI Whole earth telescope observations of the helium interacting binary PG 1346+082 (CR Bootis) SO ASTROPHYSICAL JOURNAL LA English DT Article DE stars, individual (PG 1346 + 082); stars, oscillations; white dwarfs ID AM-CANUM-VENATICORUM; ACCRETION DISK; HZ 29; NOVA; SPECTROSCOPY; DEGENERATE; VARIABLES; CVN AB We present our analysis of 240 hr of white-light, high-speed photometry of the dwarf nova-like helium variable PG 1346+082 (CR Boo). We identify two frequencies in the low-state power spectrum, at 679.670 +/- 0.004 mu Hz and 669.887 +/- 0.008 mu Hz. The 679.670 mu Hz variation is coherent over at least a 2 week time span, the first demonstration of a phase-coherent photometric variation in any dwarf nova-like interacting binary white dwarf system. The high-state power spectrum contains a complex fundamental with a frequency similar, but not identical, to the low-state spectrum, and a series of harmonics not detected in low state. We also uncover an unexpected dependence of the high-frequency power's amplitude and frequency structure on overall system magnitude. We discuss these findings' in light of the general AM CVn system model, particularly the implications of the high-order harmonics on future studies of disk structure, mass transfer, and disk viscosity. C1 UNIV TEXAS,MCDONALD OBSERV,AUSTIN,TX 78712. UNIV DELAWARE,DEPT PHYS & ASTRON,NEWARK,DE 19716. CALTECH,DIV PHYS MATH & ASTRON,PASADENA,CA 91125. LOS ALAMOS NATL LAB,XTA MS B220,LOS ALAMOS,NM 87545. KITT PEAK NATL OBSERV,NATL OPT ASTRON OBSERV,TUCSON,AZ 85726. BIG BEAR SOLAR OBSERV,BIG BEAR CITY,CA. UNIV ARKANSAS,DEPT PHYS & ASTRON,LITTLE ROCK,AR 72204. NASA,AMES RES CTR,MOFFETT FIELD,CA 94035. AUSTRALIAN NATL UNIV,CANBERRA,ACT,AUSTRALIA. UNIV CAPE TOWN,DEPT ASTRON,ZA-7700 RONDEBOSCH,SOUTH AFRICA. OBSERV MIDI PYRENEES,F-31400 TOULOUSE,FRANCE. OBSERV PARIS,F-92195 MEUDON,FRANCE. UNIV FED RIO GRANDE SUL,INST FIS,BR-91501970 PORTO ALEGRE,RS,BRAZIL. FLORIDA INST TECHNOL,DEPT PHYS & SPACE SCI,MELBOURNE,FL 32901. TENNESSEE STATE UNIV,CTR EXCELLENCE INFORMAT SYST,NASHVILLE,TN 37203. RP Provencal, JL (reprint author), UNIV TEXAS,DEPT ASTRON,RLM 15308,AUSTIN,TX 78712, USA. RI Kepler, S. O. /H-5901-2012 OI Kepler, S. O. /0000-0002-7470-5703 NR 29 TC 30 Z9 30 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 MAY 1 PY 1997 VL 480 IS 1 BP 383 EP 394 DI 10.1086/303971 PN 1 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WW282 UT WOS:A1997WW28200037 ER PT J AU Gawiser, E Smoot, GF AF Gawiser, E Smoot, GF TI Contribution of extragalactic infrared sources to cosmic microwave background foreground anisotropy SO ASTROPHYSICAL JOURNAL LA English DT Article DE cosmic microwave background; galaxies, spiral; infrared, galaxies ID SPIRAL GALAXIES; SPECTRAL OBSERVATIONS; COLD DUST; COBE; RADIOMETER; EMISSION; MAPS AB We estimate the level of confusion to cosmic microwave background (CMB) anisotropy measurements caused by extragalactic infrared sources. CMB anisotropy observations at high resolution and high frequencies are especially sensitive to this foreground. We use data from the COBE satellite to generate a Galactic emission spectrum covering millimeter and submillimeter wavelengths. Using this spectrum as a template, we predict the microwave emission of the 5319 brightest infrared galaxies seen by IRAS. We simulate sky maps of extragalactic infrared sources over the relevant range of frequencies (30-900 GHz) and instrument resolutions (10'-10 degrees FWHM). An analysis of the temperature anisotropy of these ski maps shows that a reasonable observational window is available for CMB anisotropy measurements. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP UNIV CALIF BERKELEY, DEPT PHYS, BERKELEY, CA 94720 USA. NR 29 TC 23 Z9 23 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0004-637X EI 1538-4357 J9 ASTROPHYS J JI Astrophys. J. PD MAY 1 PY 1997 VL 480 IS 1 BP L1 EP L4 DI 10.1086/310610 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WW284 UT WOS:A1997WW28400001 ER PT J AU Sion, EM Cheng, FH Sparks, WM Szkody, P Huang, M Hubeny, I AF Sion, EM Cheng, FH Sparks, WM Szkody, P Huang, M Hubeny, I TI Evidence of a thermonuclear runaway and proton-capture material on a white dwarf in a dwarf nova SO ASTROPHYSICAL JOURNAL LA English DT Article DE novae, cataclysmic variables; stars, individual (VW Hydri); white dwarfs ID VW-HYDRI; MASS AB We present Hubble Space Telescope Goddard High-Resolution Spectrograph G160M spectra of the white dwarf in VW Hydri, exposed during quiescence, 1 month after the end of a normal dwarf nova outburst. Our spectra, covering the wavelength interval 1236-1272 Angstrom, were obtained at orbital phase 0.06-1.60; they reveal strong photospheric Si II lambda lambda 1260, 1265 absorption features and a previously unidentified broad feature centered around 1250 Angstrom. This feature is due to a blend of phosphorus lines. From line-shift measurements we determine a gravitational redshift of 58 +/- 33 km s(-1), yielding a white dwarf mass M-wd = 0.86(-0.32)(+0.18) M. (this is only the second gravitational redshift determined for a cataclysmic variable white dwarf), white dwarf radius R-wd = 6.5(-1.5)(+3.1) x 10(8) cm, and gravity log g = 8.43(-0.54)(+0.31). Our best-fitting synthetic spectra yield white dwarf effective temperature T-wd = 22,000 K and a rotational velocity V-rot = 400 km s(-1). The chemical abundances, in number relative to solar, are, for C, 0.5; N, 5.0; O, 2.0; Fe, 0.5; Si, 0.1; P, 900; and all other metals, 0.3. The abundance of phosphorus being 900 solar, coupled with the elevated aluminum abundance reported by Sion and coworkers, suggest nucleosynthetic production of these odd-numbered nuclei from proton capture on the even-numbered nuclei during a CNO thermonuclear runaway (TNR) on the white dwarf. It is clear that the white dwarf has undergone a runaway sometime in the past, the first such evidence of a TNR in a dwarf nova. A TNR on a slowly accreting 0.86 M. white dwarf should produce a classical nova explosion. If our interpretation is correct, then we have found the first direct spectroscopic link between a dwarf nova and a classical nova by using the white dwarf surface chemical abundance. This is also the first direct evidence of proton capture-processed material in the atmosphere of a white dwarf. Nova explosions on more numerous, lower mass C-O white dwarfs may therefore account for some fraction of the short-lived radionuclide Al-26 in the Galaxy. This nuclide is observed from its Galactic gamma-ray line emission and is postulated to have an important role in the heating of small bodies in the solar system. C1 UNIV SCI & TECHNOL CHINA,CTR ASTROPHYS,ANHUA 230026,PEOPLES R CHINA. LOS ALAMOS NATL LAB,NUCL & HYDRODYNAM APPLICAT GRP,LOS ALAMOS,NM 87544. UNIV WASHINGTON,DEPT ASTRON,SEATTLE,WA 98195. NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. RP Sion, EM (reprint author), VILLANOVA UNIV,DEPT ASTRON & ASTROPHYS,VILLANOVA,PA 19085, USA. NR 24 TC 42 Z9 42 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 MAY 1 PY 1997 VL 480 IS 1 BP L17 EP L20 DI 10.1086/310623 PN 2 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WW284 UT WOS:A1997WW28400005 ER PT J AU Robinson, AL Sextro, RG Fisk, WJ AF Robinson, AL Sextro, RG Fisk, WJ TI Soil-gas entry into an experimental basement driven by atmospheric pressure fluctuations - Measurements, spectral analysis, and model comparison SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE radon; atmospheric pressure; indoor-air quality; contaminant transport; soil-gas transport ID RADON ENTRY; AIR-FLOW; BUILDINGS; TRANSPORT AB To study the effects of atmospheric pressure fluctuations on the entry of radon and soil-gas contaminants into houses, we have simultaneously measured the changes in atmospheric pressure and the gas flow rate between the interior of an experimental basement structure and the underlying soil. Atmospheric pressure fluctuations draw soil gas into the experimental basement without the indoor-outdoor pressure differences commonly associated with advective entry of soil-gas contaminants. The soil-gas Bow rate induced by a change in atmospheric pressure depends on both the characteristic response time of the soil and the time-rate-of-change of the atmospheric pressure fluctuation. Spectral analysis indicates that relatively low-frequency fluctuations in atmospheric pressure are the most important for driving soil-gas into and out the of the experimental structure; more than 60% of the total power of the soil-gas Bow spectrum occurs at frequencies less than 100 d(-1). A transient finite-element model based on Darcy's law correctly predicts both the dynamics and the magnitude of the observed gas flow. Atmospheric pressure fluctuations may increase the long-term radon entry rate into the experimental structure by as much as 0.2 Bq s(-1), which is more than twice the measured diffusive entry rate into the structure and comparable to the radon entry rate driven by a -0.4 Pa, steady indoor-outdoor pressure difference. (C) 1997 Elsevier Science Ltd. RP Robinson, AL (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,INDOOR ENVIRONM PROGRAM,1 CYCLOTRON RD,BLDG 90-3058,BERKELEY,CA 94720, USA. RI Robinson, Allen/I-5713-2012; Robinson, Allen/M-3046-2014 OI Robinson, Allen/0000-0003-1053-7090; Robinson, Allen/0000-0002-1819-083X NR 28 TC 17 Z9 17 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1997 VL 31 IS 10 BP 1477 EP 1485 DI 10.1016/S1352-2310(96)00304-4 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WR160 UT WOS:A1997WR16000010 ER PT J AU Robinson, AL Sextro, RG Riley, WJ AF Robinson, AL Sextro, RG Riley, WJ TI Soil-gas entry into houses driven by atmospheric pressure fluctuations - The influence of soil properties SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE radon; atmospheric pressure; indoor-air quality; contaminant transport; soil-gas transport ID RADON ENTRY; BUILDINGS; TRANSPORT; AIR AB Atmospheric pressure fluctuations can draw soil gas into houses without the indoor-outdoor pressure differences commonly associated with the advective entry of radon and other soil-gas contaminants. To study this phenomenon, we employ a transient finite-element model based on Darcy's law to simulate the soil-gas flow around a prototypical basement caused by changes in atmospheric pressure. The characteristic response time and the capacitance of the soil are used to characterize how changes in permeability, air-filled porosity, and water-table depth affect this soil-gas how. The shorter the characteristic response time and the larger the capacitance of the soil, the larger the soil-gas flow rate into a basement caused by a given fluctuation in atmospheric pressure. Such a soil must have a high permeability and a large air-filled porosity. The addition of a high permeability subslab gravel layer increases the soil-gas how rate into the basement by a factor of similar to 3. Relative to entry driven by steady indoor-outdoor pressure differences, contaminant entry induced by atmospheric pressure fluctuations will likely be most important in houses situated in a soil of low permeability (<10(-12) m(2)) and large air-filled porosity. (C) 1997 Elsevier Science Ltd. RP Robinson, AL (reprint author), ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,INDOOR ENVIRONM PROGRAM,1 CYCLOTRON RD,BLDG 90-3058,BERKELEY,CA 94720, USA. RI Robinson, Allen/I-5713-2012; Robinson, Allen/M-3046-2014; Riley, William/D-3345-2015 OI Robinson, Allen/0000-0003-1053-7090; Robinson, Allen/0000-0002-1819-083X; Riley, William/0000-0002-4615-2304 NR 15 TC 16 Z9 16 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1997 VL 31 IS 10 BP 1487 EP 1495 DI 10.1016/S1352-2310(97)83264-5 PG 9 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WR160 UT WOS:A1997WR16000011 ER PT J AU Arndt, RL Carmichael, GR Streets, DG Bhatti, N AF Arndt, RL Carmichael, GR Streets, DG Bhatti, N TI Sulfur dioxide emissions and sectorial contributions to sulfur deposition in Asia SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE acid deposition; Asia; biomass; critical loads; long-range transport; RAINS-ASIA; sulfur emissions inventory and deposition ID LONG-RANGE TRANSPORT; ACID-RAIN AB Anthropogenic and volcanic emissions of SO2 in Asia for 1987-1988 are estimated on a 1 degrees x 1 degrees grid. Anthropogenic sources are estimated to be 31.6 Tg of SO2 with the regions' volcanoes emitting an additional 3.8 Tg. For Southeast Asia and the Indian sub-continent, the emissions are further partitioned into biomass, industrial, utilities, and non-specific sources. In these regions emissions from biomass, utilities and industrial sources account for 16.7, 21.7, and 12.2%, respectively. In Bangladesh, similar to 90% of the SO2 emissions result from biomass burning and nearly 20% of India's 5 Tg of SO2 emissions are due to biomass burning. Malaysia and Singapore's emissions are dominated by the utilities with 42 and 62% of their respective emissions coming from that sector. The spatial distribution of sulfur deposition resulting from these emissions is calculated using an atmospheric transport and deposition model. Sulfur deposition in excess of 2 g m(-2) yr(-1) is predicted in vast regions of east Asia, India, Thailand, Malaysia, Taiwan, and Indonesia with deposition in excess of 5 g m(-2) yr(-1) predicted in southern China. For the Indian subcontinent and Southeast Asia the contribution of biomass burning, industrial activities, and utilities to total sulfur emissions and deposition patterns are evaluated. Biomass burning is found to be a major source of sulfur deposition throughout southeast Asia. Deposition in Bangladesh and northern India is dominated by this emissions sector. Deposition in Thailand, the Malay Peninsula and the island of Sumatra is heavily influenced by emissions from utilities. The ecological impact of the deposition, in 1988 and in the year 2020, is also estimated using critical loads data developed in the RAINS-ASIA projects. Much of eastern China, the Korean Peninsula, Japan, Thailand, and large regions of India, Nepal, Bangladesh, Taiwan, the Philippines, Malaysia, Indonesia, and sections of Vietnam are at risk due to deposition in excess of their critical loads if emission trends continue at the current rate. (C) 1997 Elsevier Science Ltd. C1 ARGONNE NATL LAB,DECIS & INFORMAT SCI DIV,ARGONNE,IL 60439. RP Arndt, RL (reprint author), UNIV IOWA,DEPT CHEM & BIOCHEM ENGN,CTR GLOBAL & REG ENVIRONM RES,IOWA CITY,IA 52242, USA. OI Streets, David/0000-0002-0223-1350 NR 45 TC 105 Z9 117 U1 0 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1997 VL 31 IS 10 BP 1553 EP 1572 DI 10.1016/S1352-2310(96)00236-1 PG 20 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WR160 UT WOS:A1997WR16000016 ER PT J AU Streets, DG Carmichael, GR Arndt, RL AF Streets, DG Carmichael, GR Arndt, RL TI Sulfur dioxide emissions and sulfur deposition from international shipping in Asian waters SO ATMOSPHERIC ENVIRONMENT LA English DT Article DE sulfur dioxide; emissions; Asia; shipping sulfur deposition AB Emissions of sulfur dioxide from international shipping in Asian waters have been estimated using information on typical shipping parameters and quantities of goods shipped to and from the major ports. Emissions are estimated to be 236,000 t SO2 per year in 1988. This represents 11.7% of emissions in Southeast Asia and 0.7% of total continental Asian emissions. Emissions from vessels in transit between ports are estimated to be 226,000 t SO2 per year, and emissions from port activities are estimated to be 10,200 t SO2 per year. Deposition of this sulfur was calculated using the ATMOS model of atmospheric transport and deposition. Shipping emissions were found to be the dominant source of sulfur deposition in large areas of the Indian Ocean, the western Pacific Ocean, and the South China Sea. Land areas most heavily affected are those bordering the Strait of Malacca, where portions of Sumatra, peninsular Malaysia, and Singapore have contributions from shipping in excess of 10% of total sulfur deposition. Observational data in Malaysia are consistent with these findings. It is suggested that emissions from shipping may be contributing to ecological damage in areas surrounding the Strait of Malacca. (C) 1997 Elsevier Science Ltd. C1 UNIV IOWA,DEPT CHEM & BIOCHEM ENGN,IOWA CITY,IA 52242. RP Streets, DG (reprint author), ARGONNE NATL LAB,DECIS & INFORMAT SCI DIV,9700 S CASS AVE,ARGONNE,IL 60439, USA. OI Streets, David/0000-0002-0223-1350 NR 19 TC 28 Z9 28 U1 0 U2 7 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1352-2310 J9 ATMOS ENVIRON JI Atmos. Environ. PD MAY PY 1997 VL 31 IS 10 BP 1573 EP 1582 DI 10.1016/S1352-2310(96)00204-X PG 10 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA WR160 UT WOS:A1997WR16000017 ER PT J AU Hansen, ADA Polissar, AV Schnell, RC AF Hansen, ADA Polissar, AV Schnell, RC TI Airborne aerosol and black carbon measurements over the East Siberian Sea, Spring 1992 SO ATMOSPHERIC RESEARCH LA English DT Article ID POLLUTION; BARROW; AIR AB In April 1992 we performed measurements of Arctic aerosol properties from an aircraft flying over the East Siberian Sea from Cherskiy (69 degrees N, 161 degrees E) to Bennett Island (76.5 degrees N, 149 degrees E). Eight round-trip flights were made over this 1000 kilometer path, with each flight incorporating several profiling descents from approximately 4.2 km altitude to the surface. On a 10-second time base were recorded measurements of aerosol black carbon (BC), condensation nuclei (CN), air temperature and absolute barometric pressure, from which altitude was deduced. Some profiles showed considerable vertical structure with numerous temperature inversions and stratified aerosol layers. Peak BC and CN concentrations exceeded 1000 ng m(-3) and 1000 cm(-3) respectively. Occasionally, extremely clean air was found in some layers. Other descents showed stable temperature profiles, with aerosol BC and CN distributed throughout the lower 4 km of the atmosphere. In most cases, the surface temperature-inversion layer contained high concentrations of aerosol species. We conclude that the atmosphere in this remote area is strongly affected by anthropogenic emissions from distant source regions, and that the meteorological and aerosol concentration profile structures were similar to those regularly observed in the western sectors of the Arctic in springtime. (C) 1997 Elsevier Science B.V. C1 NOAA,CMDL,MAUNA LOA OBSERV,HILO,HI 96720. RUSSIAN ACAD SCI,INST ATMOSPHER PHYS,MOSCOW,RUSSIA. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA. NR 20 TC 5 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 0169-8095 J9 ATMOS RES JI Atmos. Res. PD MAY PY 1997 VL 44 IS 1-2 BP 153 EP 165 DI 10.1016/S0169-8095(96)00036-1 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XH721 UT WOS:A1997XH72100013 ER PT J AU Kuznetsov, YG Malkin, AJ Land, TA DeYoreo, JJ Barba, AP Konnert, J McPherson, A AF Kuznetsov, YG Malkin, AJ Land, TA DeYoreo, JJ Barba, AP Konnert, J McPherson, A TI Molecular resolution imaging of macromolecular crystals by atomic force microscopy SO BIOPHYSICAL JOURNAL LA English DT Article ID BEAN CANAVALIA-ENSIFORMIS; TOBACCO MOSAIC-VIRUS; 3-DIMENSIONAL STRUCTURE; IN-SITU; GROWTH; PROTEIN; MECHANISMS; CRYSTALLIZATION AB Atomic force microscopy (AFM) images at the molecular level have been obtained for a number of different protein and virus crystals. They can be utilized in some special cases to obtain information useful to crystal structure analyses by x-ray diffraction. In particular, questions of space group enantiomer, the packing of molecules within a unit cell, the number of molecules per asymmetric unit, and the dispositions of multiple molecules within the asymmetric unit may be resolved. In addition, because of the increasing sensitivity and resolution of the AFM technique, some molecular features of very large asymmetric units may be within reach. We describe here high-resolution studies, using AFM, to visualize individual molecules and viruses in their crystal lattices. These investigations included fungal lipase, lysozyme, thaumatin, canavalin, and satellite tobacco mosaic virus (STMV). C1 UNIV CALIF RIVERSIDE,DEPT BIOCHEM,RIVERSIDE,CA 92521. LAWRENCE LIVERMORE NATL LAB,DEPT CHEM & MAT SCI,LIVERMORE,CA 94550. USN,RES LAB,STRUCT MATTER LAB,WASHINGTON,DC 20375. NR 24 TC 79 Z9 79 U1 1 U2 13 PU BIOPHYSICAL SOCIETY PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3998 SN 0006-3495 J9 BIOPHYS J JI Biophys. J. PD MAY PY 1997 VL 72 IS 5 BP 2357 EP 2364 PG 8 WC Biophysics SC Biophysics GA WV984 UT WOS:A1997WV98400044 PM 9129839 ER PT J AU Philippidis, GP Hatzis, C AF Philippidis, GP Hatzis, C TI Biochemical engineering analysis of critical process factors in the biomass-to-ethanol technology SO BIOTECHNOLOGY PROGRESS LA English DT Article ID ENZYMATIC-HYDROLYSIS; SIMULTANEOUS SACCHARIFICATION; CELLULOSE; FERMENTATION AB Ethanol from cellulosic biomass is a promising renewable liquid transportation fuel. Applied research in the area of biomass conversion to ethanol in the last 20 years has answered most of the major challenges on the road to commercialization but, as with any new technology, there is still room for performance improvement. A verified mathematical model was used to examine the most critical biochemical engineering aspects of ethanol production in this study. Extensive simulations of the simultaneous saccharification and fermentation (SSF) of cellulose were conducted to identify the effects of operating conditions, pretreatment effectiveness, microorganism parameters, and enzyme characteristics on ethanol production. The results clearly show that the biomass-enzyme interaction plays a dominant role in determining the performance of SSF in batch and continuous operating modes. In particular, the digestibility of the substrate (as a result of pretreatment) and the cellulase enzyme dosage, specific activity, and composition had a profound effect on ethanol yield. This investigation verified the conclusion that R&D emphasis should be placed on developing more effective pretreatment methods and producing cellulase preparations of high specific activity (low cost per enzyme unit) to realize gains fi om any development of advanced hexose/pentose-fermenting organisms. C1 NATL RENEWABLE ENERGY LAB, ALTERNAT FUELS DIV, GOLDEN, CO 80401 USA. RP Philippidis, GP (reprint author), THERMO FIBERGEN INC, BIOCHEM DEV DIV, 8 ALFRED CIRCLE, BEDFORD, MA 01730 USA. RI Hatzis, Christos/M-3867-2015 OI Hatzis, Christos/0000-0002-8120-2290 NR 22 TC 46 Z9 47 U1 0 U2 6 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 8756-7938 J9 BIOTECHNOL PROGR JI Biotechnol. Prog. PD MAY-JUN PY 1997 VL 13 IS 3 BP 222 EP 231 DI 10.1021/bp970017u PG 10 WC Biotechnology & Applied Microbiology; Food Science & Technology SC Biotechnology & Applied Microbiology; Food Science & Technology GA XC684 UT WOS:A1997XC68400002 PM 9190073 ER PT J AU Stevens, RT Ashwood, TL Sleeman, JM AF Stevens, RT Ashwood, TL Sleeman, JM TI Mercury in hair of muskrats (Ondatra zibethicus) and mink (Mustela vison) from the US Department of Energy Oak Ridge Reservation SO BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID ACCUMULATION; RIVER C1 TENNESSEE TECHNOL UNIV,DEPT BIOL,COOKEVILLE,TN 38505. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. UNIV TENNESSEE,COLL VET MED,DEPT COMPARAT MED,KNOXVILLE,TN 37901. NR 19 TC 16 Z9 16 U1 1 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0007-4861 J9 B ENVIRON CONTAM TOX JI Bull. Environ. Contam. Toxicol. PD MAY PY 1997 VL 58 IS 5 BP 720 EP 725 PG 6 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WQ347 UT WOS:A1997WQ34700006 PM 9115133 ER PT J AU Petersen, RL Hanna, SR Miller, RL Shannon, JD Hill, JD Rao, ST Lindsey, CG Haynes, EM Lamb, BK Jersey, GR Yamada, T Hoffnagle, GF Neilsen, MP Barone, JB Palma, T Mirabella, VA Wagner, KK Fransioli, PM Paine, RJ Turner, DB AF Petersen, RL Hanna, SR Miller, RL Shannon, JD Hill, JD Rao, ST Lindsey, CG Haynes, EM Lamb, BK Jersey, GR Yamada, T Hoffnagle, GF Neilsen, MP Barone, JB Palma, T Mirabella, VA Wagner, KK Fransioli, PM Paine, RJ Turner, DB TI Ninth Joint Conference on Applications of Air Pollution Meteorology SO BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY LA English DT Editorial Material C1 SIGMA RES EARTHTECH,CONCORD,MA. OAK RIDGE NATL LAB,OAK RIDGE,TN. ARGONNE NATL LAB,ARGONNE,IL 60439. BECHTEL CORP,HOUSTON,TX. NEW YORK STATE DEPT ENVIRONM CONSERVAT,ALBANY,NY. SONOMA TECHNOL,SANTA ROSA,CA. WASHINGTON STATE UNIV,PULLMAN,WA 99164. MOBIL TECHNOL CO,PAULSBORO,NJ. YAMADA SCI & ART CORP,LOS ALAMOS,NM. TRC ENVIRONM CONSULTANTS,WINDSOR,CT. ERM N CENT INC,DEERFIELD,IL. ROY F WESTON INC,W CHESTER,PA 19380. INT TECHNOL CORP,DURHAM,NC. SO CALIF EDISON CO,ROSEMEAD,CA. ATMOSPHER INFORMAT SYST,NORMAN,OK. SAIC,LAS VEGAS,NV. ENSR CONSULTING & ENGN,ACTON,MA. TRINITY CONSULTANTS,CHAPEL HILL,NC. RP Petersen, RL (reprint author), CERMAK PETERKA PETERSEN INC,1415 BLUE SPRUCE DR,FT COLLINS,CO 80524, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0003-0007 J9 B AM METEOROL SOC JI Bull. Amer. Meteorol. Soc. PD MAY PY 1997 VL 78 IS 5 BP 853 EP 865 PG 13 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA XD572 UT WOS:A1997XD57200009 ER PT J AU Smith, FG AF Smith, FG TI A model of transient mixing in a stirred tank SO CHEMICAL ENGINEERING SCIENCE LA English DT Article DE mixing; numerical model; particle dispersion; agitated tank; turbulence; transient flow ID 3-DIMENSIONAL TURBULENT-FLOW; PREDICTION AB A model describing two-dimensional transient mixing phenomena of a single-phase fluid within a stirred tank has been developed. The model employs a k-epsilon turbulence model and uses Lagrangian tracer particles as indicators of mixing behavior. Calculations over a relatively coarse (20 x 30) mesh containing 4800 tracer particles are capable of producing a realistic depiction of slurry mixing behavior in a large-scale industrial vessel. (C) 1997 Elsevier Science Ltd. RP Smith, FG (reprint author), WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29808, USA. NR 18 TC 10 Z9 10 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0009-2509 J9 CHEM ENG SCI JI Chem. Eng. Sci. PD MAY PY 1997 VL 52 IS 9 BP 1459 EP 1478 DI 10.1016/S0009-2509(96)00472-1 PG 20 WC Engineering, Chemical SC Engineering GA WV103 UT WOS:A1997WV10300004 ER PT J AU Althorpe, SC Kouri, DJ Hoffman, DK Moiseyev, N AF Althorpe, SC Kouri, DJ Hoffman, DK Moiseyev, N TI A time-independent wavepacket approach to the (t,t')-method for treating time-dependent Hamiltonian systems SO CHEMICAL PHYSICS LA English DT Article ID LIPPMANN-SCHWINGER EQUATIONS; SCHRODINGER-EQUATION; REACTIVE SCATTERING; T,T' METHOD; T' METHOD; QUANTUM DYNAMICS; POTENTIALS AB We derive the appropriate ''time-independent wavepacket'' (TIW) form of the Schrodinger equation governing collisions involving a time-dependent interaction. This is done using the (t, t')-method, whereby the time-dependence is treated like an additional spatial variable, t', and a quasi-time, t, is introduced of which the Hamiltonian is independent. The TIW equation is solved numerically by a Chebyshev expansion method which separates dependence on the initial energy from dependence on the Hamiltonian. This results in a very efficient computational procedure which we illustrate by application to scattering through an oscillating square-barrier potential. (C) 1997 Elsevier Science B.V. C1 UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204. IOWA STATE UNIV,DEPT CHEM,AMES,IA 50011. IOWA STATE UNIV,AMES LAB,AMES,IA 50011. TECHNION ISRAEL INST TECHNOL,DEPT CHEM,IL-32000 HAIFA,ISRAEL. TECHNION ISRAEL INST TECHNOL,MINERVA CTR NONLINEAR PHYS COMPLEX SYST,IL-32000 HAIFA,ISRAEL. RP Althorpe, SC (reprint author), UNIV HOUSTON,DEPT CHEM,UNIV PK,HOUSTON,TX 77204, USA. NR 35 TC 14 Z9 14 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD MAY 1 PY 1997 VL 217 IS 2-3 BP 289 EP 296 DI 10.1016/S0301-0104(97)00062-1 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WZ604 UT WOS:A1997WZ60400014 ER PT J AU Dillon, CT Lay, PA Cholewa, M Legge, GJF Bonin, AM Collins, TJ Kostka, KL SheaMcCarthy, G AF Dillon, CT Lay, PA Cholewa, M Legge, GJF Bonin, AM Collins, TJ Kostka, KL SheaMcCarthy, G TI Microprobe X-ray absorption spectroscopic determination of the oxidation state of intracellular chromium following exposure of V79 Chinese hamster lung cells to genotoxic chromium complexes SO CHEMICAL RESEARCH IN TOXICOLOGY LA English DT Article ID MAMMALIAN-CELLS; IN-VITRO; DNA; CHROMATE; CARCINOGENS; REDUCTION; CLEAVAGE; CANCERS; DAMAGE AB The oxidation state of intracellular chromium has been determined directly in mammalian lung cells exposed to mutagenic and carcinogenic chromium compounds. Microprobe X-ray absorption spectroscopy (XAS) experiments on single V79 Chinese hamster lung cells showed that Cr(VI) and Cr(V) complexes were reduced completely (>90%) to Cr(III) within 4 h of exposure of the cells. This result provides direct evidence for the hypothesis that these genotoxic oxidants react rapidly with intracellular reductants. C1 UNIV SYDNEY,SCH CHEM,SYDNEY,NSW 2006,AUSTRALIA. UNIV MELBOURNE,SCH PHYS,MICRO ANALYT RES CTR,PARKVILLE,VIC 3052,AUSTRALIA. INST NUCL PHYS,KRAKOW,POLAND. WORKSAFE AUSTRALIA,SYDNEY,NSW 2001,AUSTRALIA. CARNEGIE MELLON UNIV,DEPT CHEM,PITTSBURGH,PA 15213. UNIV CHICAGO,CARS,NATL SYNCHROTRON LIGHT SOURCE DEPT,BROOKHAVEN NATL LAB,UPTON,NY 11973. RI Cholewa, Marian/C-9474-2011; Lay, Peter/B-4698-2014; OI Lay, Peter/0000-0002-3232-2720 NR 23 TC 44 Z9 44 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0893-228X J9 CHEM RES TOXICOL JI Chem. Res. Toxicol. PD MAY PY 1997 VL 10 IS 5 BP 533 EP 535 DI 10.1021/tx970010m PG 3 WC Chemistry, Medicinal; Chemistry, Multidisciplinary; Toxicology SC Pharmacology & Pharmacy; Chemistry; Toxicology GA XA008 UT WOS:A1997XA00800007 PM 9168250 ER PT J AU Harrison, WTA Phillips, MLF Stucky, GD AF Harrison, WTA Phillips, MLF Stucky, GD TI Single-crystal structures and optical properties of the nonlinear optical KTiOPO4-type materials K0.55Li0.45TiOPO4 and K0.54Li0.46TiOAsO4 prepared by molten salt ion-exchange SO CHEMISTRY OF MATERIALS LA English DT Article ID PARAELECTRIC PHASE-TRANSITION; POTASSIUM TITANYL PHOSPHATE; SUBSTITUTION CHEMISTRY; STRUCTURE FIELD; RBTIOPO4; TLTIOPO4; RB AB Single crystals of the KTiOPO4 (KTP) type phases K0.55Li0.45TiOPO4 and K0.54Li0.46TiOAsO4 have been prepared by molten salt ion-exchange reactions from their potassium-containing precursors. After ion-exchange, both phases maintain the distinctive distorted TiO6 octahedra seen in KTiOPO4 and KTiOAsO4. The pattern of lithium-ion substitution differs for these two phases: In K0.55Li0.45TiOPO4, Li substitutes for both of the two crystallographically distinct potassium cations to roughly equal extent, whereas in K0.54Li0.46TiOAsO4, the 9-coordinate K(2) atom is preferentially replaced by Li. The lithium cations occupy six-rings of TiO6 and PO4 polyhedra and adopt approximate square-planar coordination in both these materials. Second harmonic generation at 1064 nm is not significantly affected by lithium substitution in either of these phases. Crystal data: K0.55Li0.45TiOPO4: M-r = 183.55, orthorhombic, space group Pna2(1) (No. 33), a = 12.741(2) Angstrom, b = 6.357(1) Angstrom, c = 10.535(2) Angstrom, V = 853(2) Angstrom(3), Z = 8, R(F) = 3.31% for 1393 reflections with I > 3 sigma(I). K0.54Li0.46TiOAsO4: M-r = 227.11, orthorhombic, space group Pna2(1) (N0. 33), a = 13.018(2) Angstrom, b = 6.589(1) Angstrom, c = 10.766(2) Angstrom, V = 923(2) Angstrom(3), Z = 8, R(F) = 3.76% for 1637 reflections [I > 3 sigma(I)]. C1 SANDIA NATL LABS,DEPT 1815,ALBUQUERQUE,NM 87185. UNIV CALIF SANTA BARBARA,DEPT CHEM,SANTA BARBARA,CA 93106. RP Harrison, WTA (reprint author), UNIV WESTERN AUSTRALIA,DEPT CHEM,NEDLANDS,WA 6907,AUSTRALIA. NR 31 TC 13 Z9 13 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 MAY PY 1997 VL 9 IS 5 BP 1138 EP 1144 DI 10.1021/cm960529o PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ300 UT WOS:A1997WZ30000015 ER PT J AU Kojima, M Magill, JH Lin, JS Magonov, SN AF Kojima, M Magill, JH Lin, JS Magonov, SN TI Structure and morphology of biaxially oriented films of polyethylenes SO CHEMISTRY OF MATERIALS LA English DT Article AB Biaxially oriented films of commercial polyethylenes were investigated using X-ray diffraction in directions transverse and perpendicular to the film plane. The surface morphology of the inner and outer faces of these films were studied in two directions by (a) transmission election microscopy employing replication procedures, (b) by atomic force microscopy (tapping mode) down to nanometer resolution, (c) scanning electron microscopy of ion-etched metal coated surfaces, and (d) small-angle X-ray scattering measurements obtained from the bulk films. Discernible differences in morphological features were found for the inner and outer film faces that experienced different conditions during blow extrusion. The mean surface roughness of the films was measured and correlated with the haze parameters of these polyolefin materials. Trends in surface roughness with crystallinity (assessed from other measurements) are attributed to surface lamellar-like crystallization. C1 UNIV PITTSBURGH,SCH ENGN,PITTSBURGH,PA 15261. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. DIGITAL INSTRUMENTS,SANTA BARBARA,CA 93103. NR 14 TC 13 Z9 14 U1 0 U2 11 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAY PY 1997 VL 9 IS 5 BP 1145 EP 1153 DI 10.1021/cm960505h PG 9 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ300 UT WOS:A1997WZ30000016 ER PT J AU Grate, JW Kaganove, SN Patrash, SJ Craig, R Bliss, M AF Grate, JW Kaganove, SN Patrash, SJ Craig, R Bliss, M TI Hybrid organic/inorganic copolymers with strongly hydrogen-bond acidic properties for acoustic wave and optical sensors SO CHEMISTRY OF MATERIALS LA English DT Article ID PATTERN-RECOGNITION; VAPOR SENSORS; CONDENSATION POLYMERIZATION; PHOSPHORUS ESTERS; SORBENT COATINGS; RESPONSES; HYDROSILATION; MICROSENSORS; POLYMERS; SORPTION AB Hybrid organic/inorganic polymers have been prepared incorporating fluoroalkyl-substituted bisphenol groups linked using oligosiloxane spacers. These hydrogen-bond acidic materials have glass-to-rubber transition temperatures below room temperature and are excellent sorbents for basic vapors. The physical properties such as viscosity and refractive index can be tuned by varying the length of the oligosiloxane spacers and the molecular weight. In addition, the materials are easily cross-linked to yield solid elastomers. The potential use of these materials for chemical sensing has been demonstrated by applying them to surface acoustic wave devices as thin films and detecting the hydrogen-bond basic vapor dimethyl methylphosphonate with high sensitivity. It has also been demonstrated that one of these materials with suitable viscosity and refractive index can be used to clad silica optical fibers; the cladding was applied to freshly drawn fiber using a fiber drawing tower. These fibers have potential as evanescent wave optical fiber sensors. C1 PACIFIC NW LAB, ENGN & ANALYT SCI DEPT, RICHLAND, WA 99352 USA. PACIFIC NW LAB, DEPT CHEM & MAT SCI, RICHLAND, WA 99352 USA. RP Grate, JW (reprint author), PACIFIC NW LAB, ENVIRONM MOL SCI LAB, POB 999, RICHLAND, WA 99352 USA. RI Bliss, Mary/G-2240-2012 OI Bliss, Mary/0000-0002-7565-4813 NR 38 TC 73 Z9 77 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAY PY 1997 VL 9 IS 5 BP 1201 EP 1207 DI 10.1021/cm960590t PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ300 UT WOS:A1997WZ30000025 ER PT J AU Hanninen, T Mutikainen, I Saanila, V Ritala, M Leskela, M Hanson, JC AF Hanninen, T Mutikainen, I Saanila, V Ritala, M Leskela, M Hanson, JC TI [Ca(Thd)(2)(tetraen)]: A monomeric precursor for deposition of CaS thin films SO CHEMISTRY OF MATERIALS LA English DT Article ID ATOMIC LAYER EPITAXY; CHEMICAL-VAPOR-DEPOSITION; RAY CRYSTAL-STRUCTURES; ELECTROLUMINESCENT DEVICES; BETA-DIKETONATE; EU; COMPLEXES; OXYGEN; GROWTH; BARIUM AB [Ca-3(thd)(6)] (thd = 2,2,6,6-tetramethyl-3,5-heptanedionato) dissolved in hexane and in the presence of tetraethylenepentamine (tetraen) crystallizes as a 1:1 [Ca(thd)(2)(tetraen)] adduct complex in the orthorhombic Peen space group with a 10.874(2) Angstrom, b = 15.480(3) Angstrom, c = 20.866(4) Angstrom, and Z = 4. The molecule is monomeric with an 8-coordinated calcium atom. The adduct complex volatilized at lower temperature than the nonadducted complex. [Ca(thd)(2)(tetraen)] can be utilized as a precursor in growth CaS thin films by the atomic layer epitaxy method. The growth rate with [Ca(thd)(2)(tetraen)] is lower (0.43 Angstrom/cycle) than that with [Ca-3(thd)(6)] (0.50 Angstrom/cycle). C1 UNIV HELSINKI, DEPT CHEM, FIN-00014 HELSINKI, FINLAND. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. RI Hanson, jonathan/E-3517-2010; Ritala, Mikko/N-7268-2013; OI Ritala, Mikko/0000-0002-6210-2980; Leskela, Markku/0000-0001-5830-2800 NR 49 TC 16 Z9 16 U1 0 U2 2 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 MAY PY 1997 VL 9 IS 5 BP 1234 EP 1240 DI 10.1021/cm9606078 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ300 UT WOS:A1997WZ30000030 ER PT J AU Josowicz, M Li, J Windisch, CF Exarhos, GJ Baer, DR Samuels, WD Ulmen, MD AF Josowicz, M Li, J Windisch, CF Exarhos, GJ Baer, DR Samuels, WD Ulmen, MD TI Doping of poly(cyclophosphazene-benzoquinone) films with polyiodide SO CHEMISTRY OF MATERIALS LA English DT Article ID CONDUCTIVITY; COMPLEXES; IODINE; MECHANISM; OXIDATION AB Polyiodide is inserted into poly(cyclophosphazene-benzoquinone) (PPBQ) film from solution or vapor phase as a result of a charge-transfer interaction between the quinone oxygen and iodine. The incorporation of the polyiodide into the PPBQ film enhanced ion (or electron) transport in the film. Characterization of the PPBQ film before and after polyiodide doping with X-ray photoelectron, UV/vis and Raman spectroscopy indicates that the doping mechanism is governed by the formation of a charge-transfer complex. Raman spectra of PPBQ films suggest that polyiodide interacts with the oxygen atoms in the P-O-C linkage, where the phosphorus atom is part of the phosphazene trimer and the carbon atom is part of the aromatic ring. This is the first direct evidence for the bonding arrangement of iodine in a poly(cyclophosphazene) system. RP Josowicz, M (reprint author), PACIFIC NW LAB, RICHLAND, WA 99352 USA. RI Baer, Donald/J-6191-2013 OI Baer, Donald/0000-0003-0875-5961 NR 28 TC 1 Z9 1 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0897-4756 J9 CHEM MATER JI Chem. Mat. PD MAY PY 1997 VL 9 IS 5 BP 1285 EP 1291 DI 10.1021/cm970119f PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA WZ300 UT WOS:A1997WZ30000037 ER PT J AU Williams, MD Brown, MJ AF Williams, MD Brown, MJ TI An exploration of measures for comparing measurements with the results from meteorological models for Mexico City SO CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS LA English DT Article; Proceedings Paper CT 3rd International Conference on Environmetrics and Chemometrics CY SEP 11-13, 1995 CL LAS VEGAS, NV SP US EPA, NISS, NIST, Elsevier Sci Publ, Gulf Coast Hazardous Subst Res Ctr, Monsanto Chem Co, Texas A&M Univ DE prognostic models; complex terrain; urban air quality; measurement-model comparison; Mexico City AB Los Alamos National Laboratory and Institute Mexicano del Petroleo have completed a joint study of options for improving air quality in Mexico City. We used a three-dimensional, prognostic, higher-order turbulence model for atmospheric circulation (HOTMAC) to treat domains that include an urbanized area. We tested the model against routine measurements and those of a major field program. During the field program, measurements included: (1) lidar measurements of aerosol transport and dispersion, (2) aircraft measurements of winds, turbulence, and chemical species aloft, (3) aircraft measurements of skin temperatures, and (4) Tethersonde measurements of winds and ozone. We made both graphical and statistical comparisons and we have reported some of the comparisons to provide insight into the meaning of statistical parameters including the index of agreement. RP Williams, MD (reprint author), LOS ALAMOS NATL LAB,MAIL STOP F604,LOS ALAMOS,NM 87545, USA. OI Brown, Michael J./0000-0002-8069-0835 NR 7 TC 0 Z9 0 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7439 J9 CHEMOMETR INTELL LAB JI Chemometrics Intell. Lab. Syst. PD MAY PY 1997 VL 37 IS 1 BP 81 EP 94 DI 10.1016/S0169-7439(97)00012-9 PG 14 WC Automation & Control Systems; Chemistry, Analytical; Computer Science, Artificial Intelligence; Instruments & Instrumentation; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Automation & Control Systems; Chemistry; Computer Science; Instruments & Instrumentation; Mathematics GA XB913 UT WOS:A1997XB91300009 ER PT J AU LoPresti, CA OBrien, RF AF LoPresti, CA OBrien, RF TI Characterizing environmental pressures along the US/Mexico border: An application of the Toxics Release Inventory in environmentrics SO CHEMOMETRICS AND INTELLIGENT LABORATORY SYSTEMS LA English DT Article; Proceedings Paper CT 3rd International Conference on Environmetrics and Chemometrics CY SEP 11-13, 1995 CL LAS VEGAS, NV SP US EPA, NISS, NIST, Elsevier Sci Publ, Gulf Coast Hazardous Subst Res Ctr, Monsanto Chem Co, Texas A&M Univ DE toxics release inventory; toxic chemicals; environmental statistics; US/Mexico border AB Public data bases are becoming increasingly available to environmental researchers. We discuss use of the U.S. Environmental Protection Agency's Toxics Release Inventory data base for research purposes in the context of characterizing a geo graphical area in terms of industrial toxic chemical emissions into the environment. We present as examples highlights of ongoing exploratory data summary for the U.S. side of the U.S./Mexico border area during 1988-1992 which show how different parts of the border area have unique patterns of emissions. The TRI was the first national industrial toxic emissions inventory, and constitutes a unique and useful resource for data on industrial toxic chemical releases in the United States for researchers prepared to invest in fully understanding its strengths and limitations. RP LoPresti, CA (reprint author), PACIFIC NW LAB, DIV ENERGY, STAT GRP, POB 999, RICHLAND, WA 99352 USA. NR 11 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7439 J9 CHEMOMETR INTELL LAB JI Chemometrics Intell. Lab. Syst. PD MAY PY 1997 VL 37 IS 1 BP 95 EP 111 DI 10.1016/S0169-7439(96)00045-7 PG 17 WC Automation & Control Systems; Chemistry, Analytical; Computer Science, Artificial Intelligence; Instruments & Instrumentation; Mathematics, Interdisciplinary Applications; Statistics & Probability SC Automation & Control Systems; Chemistry; Computer Science; Instruments & Instrumentation; Mathematics GA XB913 UT WOS:A1997XB91300010 ER PT J AU Jurco, B Schlieker, M AF Jurco, B Schlieker, M TI Quantized lax equations and their solutions SO COMMUNICATIONS IN MATHEMATICAL PHYSICS LA English DT Article ID YANG-BAXTER EQUATION; QUANTUM GROUPS; ALGEBRAS; SYSTEMS AB Integrable systems on quantum groups are investigated. The Heisenberg equations possessing the Lax form are solved in terms of the solution to the factorization problem on the corresponding quantum group. C1 CERN,DIV THEORY,CH-1211 GENEVA 23,SWITZERLAND. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,THEORET PHYS GRP,BERKELEY,CA 94720. NR 36 TC 3 Z9 3 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-3616 J9 COMMUN MATH PHYS JI Commun. Math. Phys. PD MAY PY 1997 VL 185 IS 2 BP 397 EP 410 DI 10.1007/s002200050096 PG 14 WC Physics, Mathematical SC Physics GA XD175 UT WOS:A1997XD17500007 ER PT J AU Reid, MJ Lame, MW Morin, D Wilson, DW Segall, HJ AF Reid, MJ Lame, MW Morin, D Wilson, DW Segall, HJ TI Monocrotaline metabolism and distribution in Fisher 344 and Sprague-Dawley rats SO COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY LA English DT Article DE Fisher 344; liver perfusion; metabolism; monocrotalic acid; monocrotaline; pyrrolizidine alkaloid; Sprague-Dawley ID PYRROLIZIDINE ALKALOID SENECIONINE; C-14 MONOCROTALINE; GUINEA-PIG; PULMONARY TOXICITY; COVALENT BINDING; LIVER; LUNG; DIHYDROPYRROLIZINE; SENECIPHYLLINE; MACROMOLECULES AB The metabolism and distribution of C-14-monocrotaline in Fisher 344 (F344) rats was compared with that in Sprague Dawley (SD) rats. In vitro microsomal preparations, in situ isolated perfused livers and in vivo excretion and distribution studies were used to discern any differences between these two strains. These strains have previously been shown to differ in their susceptibility to monocrotaline-induced pulmonary hypertension. Hepatic phase I metabolism appears to be similar in both strains with N-oxidation and dehydrogenation to the reactive pyrroles as the major pathways. During the liver perfusions, SD rats generated more monocrotalic acid than F344 rats, but the microsome and excretion studies demonstrated no significant differences in the amount of monocrotalic acid. Monocrotalic acid is a stable byproduct of dehydromonocrotaline reacting with cellular nucleophiles and indicates the amount of monocrotaline dehydrogenation when carboxylesterase activity is negligible. These data suggest that the differences in strain susceptibility to pulmonary vascular toxicity is most likely due to differences in their response to the toxic metabolites. C1 LAWRENCE LIVERMORE NATL LAB,DEPT VET MED & MOL BIOSCI,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,DEPT PATHOL MICROBIOL & IMMUNOL,DAVIS,CA 95616. NR 41 TC 9 Z9 10 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0305-0491 J9 COMP BIOCHEM PHYS B JI Comp. Biochem. Physiol. B-Biochem. Mol. Biol. PD MAY PY 1997 VL 117 IS 1 BP 115 EP 123 DI 10.1016/S0305-0491(96)00323-9 PG 9 WC Biochemistry & Molecular Biology; Zoology SC Biochemistry & Molecular Biology; Zoology GA WX438 UT WOS:A1997WX43800014 PM 9180020 ER PT J AU Moss, SC Robertson, JL Neumann, DA Reinhard, L AF Moss, SC Robertson, JL Neumann, DA Reinhard, L TI Anomalous static displacements and their relation to lattice dynamics in Fe0.53Cr0.47 SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS AB Summarizing our prior work on X-ray and neutron scattering, we discuss the demands that careful data collection place on the interpretation and understanding of atomic size and atomic displacements in binary alloys, In the present case, when the size difference between pure Fe and pure Cr in their bcc states is only 0.6%, atom size disparities nonetheless place stringent demands on the basic physics of these solid solutions and lead to effects that resemble premonitory fluctuations above the first order phase transition to the Frank-Kasper sigma-phase characterized both by (111) planar collapse and by ordered icosahedral units. C1 OAK RIDGE NATL LAB,DIV SOLID STATE,OAK RIDGE,TN 37831. NIST,GAITHERSBURG,MD 20899. ETH ZENTRUM,CH-8092 ZURICH,SWITZERLAND. RP Moss, SC (reprint author), UNIV HOUSTON,DEPT PHYS,HOUSTON,TX 77204, USA. NR 12 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 33 EP 38 DI 10.1016/S0927-0256(97)00013-X PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000006 ER PT J AU McCormack, R Asta, M Hoyt, JJ Chakoumakos, BC Misture, ST Althoff, JD Johnson, DD AF McCormack, R Asta, M Hoyt, JJ Chakoumakos, BC Misture, ST Althoff, JD Johnson, DD TI Experimental and theoretical investigations of order-disorder in Cu2AlMn SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS ID METALLIC ALLOYS; TRANSITIONS; SYSTEM; CU; NI AB A combination of X-ray and neutron powder diffract:on has been used to measure the two long range order parameters vs. temperature below the disorder-B2 transition in the ternary alloy Cu2AlMn. The results indicate that at temperatures just below the critical point the Al + Mn sublattice is enriched in Al. First-principles calculations based on only the atomic numbers of Cu, Mn and Al support the experimentally-observed preference of Al for the Al + Mn sublattice, and reveal the interplay between the constituent binary systems that gives rise to this behavior. C1 SANDIA NATL LABS, COMPUTAT MAT SCI DEPT, LIVERMORE, CA 94551 USA. WASHINGTON STATE UNIV, SCH MECH & MAT ENGN, PULLMAN, WA 99164 USA. OAK RIDGE NATL LAB, DIV SOLID STATE, OAK RIDGE, TN 37831 USA. OAK RIDGE NATL LAB, HIGH TEMP MAT LAB, OAK RIDGE, TN 37831 USA. RP McCormack, R (reprint author), NIST, MAT SCI & ENGN LAB, GAITHERSBURG, MD 20899 USA. RI Chakoumakos, Bryan/A-5601-2016; OI Chakoumakos, Bryan/0000-0002-7870-6543; Johnson, Duane/0000-0003-0794-7283 NR 21 TC 6 Z9 6 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 39 EP 45 DI 10.1016/S0927-0256(97)00014-1 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000007 ER PT J AU Johnson, DD Asta, M AF Johnson, DD Asta, M TI Energetics of homogeneously-random fcc Al-Ag alloys: A detailed comparison of computational methods SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS ID SPECIAL QUASIRANDOM STRUCTURES; TRANSITION-METAL ALLOYS; ELECTRONIC-STRUCTURE; DENSITY; ENERGY AB Generally speaking, the formation energies, Delta E-f, of homogeneously-random alloys have important consequences for thermodynamic behavior, and, in the case of AI-Ag these energies already provide insight into the driving force for GP-zone formation. We therefore focus on a detailed comparison of three complementary (and approximate) electronic-structure-based methods for calculating Delta E-f in disordered alloys: the Korringa-Kohn-Rostoker coherent-potential approximation (KKR-CPA) method, and, based an the linear-muffin-tin orbital (LMTO) method, the so-called special quasi-random structure (SQS) method and the structural-inversion method (SIM). Although the Delta E-f versus concentration trends that we find are robust, we detail the sensitivity of the calculated energetics, and the subsequent comparisons, including: muffin-tins versus atomic-spheres, combined-corrections, charge-correlation within the CPA, and the neglect of relativity. The main finding The mixing energies obtained from the CPA, SIM, and SQS methods agree well as long as one is careful to use similar approximations amongst the different approaches!. RP Johnson, DD (reprint author), SANDIA NATL LABS,COMPUTAT MAT SCI DEPT,MS 9161,LIVERMORE,CA 94551, USA. OI Johnson, Duane/0000-0003-0794-7283 NR 31 TC 16 Z9 16 U1 3 U2 13 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 54 EP 63 DI 10.1016/S0927-0256(97)00016-5 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000009 ER PT J AU Asta, M Johnson, DD AF Asta, M Johnson, DD TI Thermodynamic properties of FCC-based Al-Ag alloys SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS ID SPECIAL QUASIRANDOM STRUCTURES; STABILITY; DENSITY; SYSTEMS; MODEL AB The energetics and thermodynamics of fee-based Al-Ag alloys have important consequences for the formation of Guinier-Preston (GP) zones in Al-rich alloys. Bulk thermodynamic properties of stable and metastable fee-based phases in the Ag-Al system are studied from first principles using quantum-mechanical, total-energy methods combined with the cluster-variation method. From the results of these calculations the metastable fee-based Ag-Al phase diagram has been calculated, Our calculated phase diagram features a monotectoid reaction. A miscibility gap in the fee solid solution phase is present above the monotectoid temperature and a two-phase field between the Al-rich solid solution and an ordered fee-based Ag2Al phase is predicted for low temperatures. Therefore,our calculations provide clear evidence that the structure of epsilon (high temperature) and eta (low temperature) GP-zone precipitates should be disordered and long-range ordered, respectively. Our preliminary findings using a full-potential electronic-structure technique indicate that lattice relaxations in the alloys can significantly alter the formation energies. RP Asta, M (reprint author), SANDIA NATL LABS, COMPUTAT MAT SCI DEPT, POB 969, MS 9161, 7011 EAST AVE, LIVERMORE, CA 94551 USA. OI Johnson, Duane/0000-0003-0794-7283 NR 44 TC 19 Z9 19 U1 4 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 64 EP 70 DI 10.1016/S0927-0256(97)00017-7 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000010 ER PT J AU Althoff, JD Johnson, DD AF Althoff, JD Johnson, DD TI Concentration-wave analysis of atomic pair correlations disordered ternary alloys: Application to Cu2NiZn SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS ID MULTICOMPONENT SOLID-SOLUTIONS AB We outline the use of the method of concentration waves to analyze the atomic pair correlations in disordered ternary alloys. We present an analysis of the correlations in the disordered state of Cu2NiZn calculated by first principles. The correlations in the disordered state are found to be a precursor to the partially-ordered state observed experimentally. C1 SANDIA NATL LABS,COMPUTAT MAT SCI DEPT,LIVERMORE,CA 94551. OI Johnson, Duane/0000-0003-0794-7283 NR 14 TC 4 Z9 4 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 71 EP 78 DI 10.1016/S0927-0256(97)00018-9 PG 8 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000011 ER PT J AU Wolverton, C Zunger, A AF Wolverton, C Zunger, A TI Ni-Au: A testing ground for theories of phase stability SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS ID SHORT-RANGE ORDER; SOLID-SOLUTIONS; ATOMIC INTERACTION; CLUSTER-EXPANSION; MISCIBILITY GAP; MONTE-CARLO; ALLOYS; THERMODYNAMICS; SCATTERING; ENERGETICS AB The theory of phase stability in the Ni-Au alloy system is a popular topic due to the large size mismatch between Ni and Au, which makes the effects of atomic relaxation critical and also to the fact that Ni-Au exhibits a phase separation tendency at low temperatures, but measurements at high-temperature show an ordering-type short-range order. We have clarified the wide disparity which exists in the previously calculated values of mixing energies and thermodynamic properties by computing 'state-of-the-art' energetics (Cull-potential, fully-relaxed LDA total energies) combined with 'state-of-the-art' statistics (k-space cluster expansion with Monte Carlo simulations) for the Ni-Au system. We find: (i) LDA provides accurate mixing energies of disordered Ni1-x Au-x alloys (Delta H-mix less than or equal to + 100 meV/atom) provided that both atomic relaxation (a similar to 100 meV/atom effect) and short-range order (similar to 25 meV/atom) are taken into account properly. (ii) Previous studies using empirical potentials or approximated LDA methods often underestimate the formation energy of ordered compounds and hence also underestimate the mixing energy of random alloys. (iii) Measured values of the total entropy of mixing combined with calculated values of the configurational entropy demonstrate that the non-configurational entropy in Ni-Au is large and leads to a significant reduction in miscibility gap temperature. (iv) The calculated short-range order agrees well with measurements and both predict ordering in the disordered phase. (v) Consequently, using inverse Monte Carlo to extract interaction energies from the measured/calculated short-range order in Ni-Au would result in interactions which would produce ordering-type mixing energies, in contradiction with both experimental measurements and precise LDA calculations. RP Wolverton, C (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. RI Wolverton, Christopher/B-7542-2009; Zunger, Alex/A-6733-2013 NR 37 TC 40 Z9 41 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 107 EP 121 DI 10.1016/S0927-0256(97)00023-2 PG 15 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000016 ER PT J AU Morgan, D deFontaine, D Asta, M AF Morgan, D deFontaine, D Asta, M TI Toward a total energy tight-binding Hamiltonian based on the linear-muffin-tin-orbital method SO COMPUTATIONAL MATERIALS SCIENCE LA English DT Article; Proceedings Paper CT Joint NFS/CNRS Workshop on Alloy Theory CY OCT 11-15, 1996 CL STRASBOURG, FRANCE SP NFS, CNRS ID ELECTRONIC-STRUCTURE; ALLOYS; ENERGETICS; STABILITY; SYSTEM AB We have investigated the accuracy of approximations involved in constructing a total energy tight-binding Hamiltonian for Au-Cu based on the linear-muffin-tin-orbital method in the atomic-sphere-approximation (LMTO-ASA). The approximations involved in constructing the tight-binding Hamiltonian are broken into four stages: (i) the use of the LMTO-ASA method, (ii) the use of only the first-order LMTO-ASA Hamiltonian, (iii) the, use of non-serf-consistent potential parameters, (iv) the use of a fit repulsive term, The equations of state are calculated for 11 different structures and compared at each stage of approximation, The: results show that for Au-Cu the tight-binding Hamiltonian produces significant overbinding and errors in the equation of state. C1 ERNEST ORLANDO LAWRENCE BERKELEY NATL LAB,DIV MAT SCI,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MAT & MINERAL ENGN,BERKELEY,CA 94720. SANDIA NATL LABS,COMPUTAT MAT SCI DEPT,LIVERMORE,CA 94551. RP Morgan, D (reprint author), UNIV CALIF BERKELEY,DEPT PHYS,BERKELEY,CA 94720, USA. NR 23 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-0256 J9 COMP MATER SCI JI Comput. Mater. Sci. PD MAY PY 1997 VL 8 IS 1-2 BP 122 EP 130 DI 10.1016/S0927-0256(97)00024-4 PG 9 WC Materials Science, Multidisciplinary SC Materials Science GA XE910 UT WOS:A1997XE91000017 ER PT J AU Chan, KS Bodner, SR Munson, DE AF Chan, KS Bodner, SR Munson, DE TI Treatment of anisotropic damage development within a scalar damage formulation SO COMPUTATIONAL MECHANICS LA English DT Article ID INELASTIC FLOW AB This paper is concerned with describing a damage mechanics formulation which provides for nonisotropic effects using a scalar damage variable. An investigation has been in progress for establishing the constitutive behavior of rock salt at long times and low to moderate confining pressures in relation to the possible use of excavated rooms in rock salt formations as repositories for nuclear waste. An important consideration is the effect of damage manifested principally by the formation of shear induced wing cracks which have a stress dependent orientation. The analytical formulation utilizes a scalar damage parameter, but is capable of indicating the non-isotropic dependence of inelastic straining on the stress state and the confining pressure. Also, the equations indicate the possibility of volumetric expansions leading to the onset of tertiary creep and eventually rupture if the damage variable reaches a critical value. C1 SW RES INST,SAN ANTONIO,TX 78238. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NR 11 TC 3 Z9 3 U1 0 U2 2 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0178-7675 J9 COMPUT MECH JI Comput. Mech. PD MAY PY 1997 VL 19 IS 6 BP 522 EP 526 DI 10.1007/s004660050203 PG 5 WC Mathematics, Interdisciplinary Applications; Mechanics SC Mathematics; Mechanics GA XE847 UT WOS:A1997XE84700013 ER PT J AU Jadach, S Placzek, W RichterWas, E Ward, BFL Was, Z AF Jadach, S Placzek, W RichterWas, E Ward, BFL Was, Z TI Upgrade of the Monte Carlo program BHLUMI for Bhabha scattering at low angles to version 4.04 SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article DE radiative corrections; Monte Carlo simulation; Bhabha scattering; bremsstrahlung; Quantum Electrodynamics (QED); electroweak theory; structure functions ID QED VACUUM POLARIZATION; HADRONIC CONTRIBUTION; LEP AB The new version of the Monte Carlo program for small-angle Bhabha scattering BHLUMI with an overall precision of 0.11% is presented, The main improvements are in the matrix element of the main multi-photon sub-generator based on the Yennie-Frautschi-Suura exponentiation, where the missing second-order terms in the leading-logarithmic (LL) approximation are supplemented and the contribution from the Z resonance is improved. In the LUMLOG sub-generator based on the LL approximation, we implement collinear photon emission in the final state and we also add a down-graded third-order LL matrix element, which has exactly the same incomplete third-order LL contribution as the multi-photon BHLUMI. The new LUMLOG is therefore capable of calculating the missing third-order LL part in the cross sections obtained from the main multi-photon event generator, for arbitrary event selection. The first-order event generator OLDBIS remains unchanged. C1 CERN, DIV THEORY, CH-1211 GENEVA 23, SWITZERLAND. UNIV TENNESSEE, DEPT PHYS & ASTRON, KNOXVILLE, TN 37996 USA. JAGIELLONIAN UNIV, INST COMP SCI, KRAKOW, POLAND. STANFORD UNIV, SLAC, STANFORD, CA 94309 USA. RP Jadach, S (reprint author), INST PHYS NUCL, UL KAWIORY 26A, KRAKOW, POLAND. NR 29 TC 107 Z9 107 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD MAY PY 1997 VL 102 IS 1-3 BP 229 EP 251 DI 10.1016/S0010-4655(96)00156-7 PG 23 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA XE359 UT WOS:A1997XE35900016 ER PT J AU Mrenna, S AF Mrenna, S TI SPYTHIA, a supersymmetric extension of PYTHIA 5.7 SO COMPUTER PHYSICS COMMUNICATIONS LA English DT Article ID NEUTRALINOS; COLLISIONS; PHYSICS; SEARCH AB SPYTHIA is an event level Monte Carlo program which simulates particle production and decay at lepton and hadron colliders in the Minimal Supersymmetric Standard Model (MSSM). It is an extension of PYTHIA 5.7, with all of its previous capabilities. This paper is meant to supplement the PYTHIA/JETSET user manual, providing a description of the new particle spectrum, hard scattering processes, and decay modes. Several examples of using the program are provided. RP Mrenna, S (reprint author), ARGONNE NATL LAB,DIV HIGH ENERGY PHYS,ARGONNE,IL 60439, USA. OI Mrenna, Stephen/0000-0001-8731-160X NR 18 TC 58 Z9 58 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0010-4655 J9 COMPUT PHYS COMMUN JI Comput. Phys. Commun. PD MAY PY 1997 VL 101 IS 3 BP 232 EP 240 DI 10.1016/S0010-4655(97)00003-9 PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WY082 UT WOS:A1997WY08200005 ER PT J AU Beazley, DM Lomdahl, PS AF Beazley, DM Lomdahl, PS TI Controlling the data glut in large-scale molecular-dynamics simulations SO COMPUTERS IN PHYSICS LA English DT Article C1 LOS ALAMOS NATL LAB,DIV THEORET,CONDENSED MATTER & STAT PHYS GRP,LOS ALAMOS,NM 87545. RP Beazley, DM (reprint author), UNIV UTAH,DEPT COMP SCI,SALT LAKE CITY,UT 84112, USA. NR 17 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 0894-1866 J9 COMPUT PHYS JI Comput. Phys. PD MAY-JUN PY 1997 VL 11 IS 3 BP 230 EP 238 PG 9 WC Computer Science, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Computer Science; Physics GA XA317 UT WOS:A1997XA31700010 ER PT J AU Furnish, G AF Furnish, G TI Disambiguated glommable expression templates SO COMPUTERS IN PHYSICS LA English DT Article RP Furnish, G (reprint author), LAWRENCE LIVERMORE NATL LAB,INERTIAL CONFINEMENT FUS CODE GRP,LIVERMORE,CA 94550, USA. NR 8 TC 11 Z9 11 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0894-1866 J9 COMPUT PHYS JI Comput. Phys. PD MAY-JUN PY 1997 VL 11 IS 3 BP 263 EP 269 PG 7 WC Computer Science, Interdisciplinary Applications; Physics, Multidisciplinary; Physics, Mathematical SC Computer Science; Physics GA XA317 UT WOS:A1997XA31700013 ER PT J AU Li, J Skjellum, A Falgout, RD AF Li, J Skjellum, A Falgout, RD TI A poly-algorithm for parallel dense matrix multiplication on two-dimensional process grid topologies SO CONCURRENCY-PRACTICE AND EXPERIENCE LA English DT Article; Proceedings Paper CT BLAS Technical Workshop CY NOV 14, 1995 CL UNIV TENNESSEE, TN SP Univ Tennessee HO UNIV TENNESSEE ID REDISTRIBUTION; COMPUTER AB In this paper, we present several new and generalized parallel dense matrix multiplication algorithms of the form C = alpha AB + beta C on two-dimensional process grid topologies, These algorithms can deal with rectangular matrices distributed on rectangular grids, We classify these algorithms coherently into three categories according to the communication primitives used and thus we offer a taxonomy for this family of related algorithms. All these algorithms are represented in the data distribution independent approach and thus do not require a specific data distribution for correctness, The algorithmic compatibility condition result shown here ensures the correctness of the matrix multiplication. We define and extend the data distribution functions and introduce permutation compatibility and algorithmic compatibility, We also discuss a permutation compatible data distribution (modified virtual 2D data distribution). We conclude that no single algorithm always achieves the best performance on different matrix and grid shapes, A practical approach to resolve this dilemma is to use poly-algorithms. We analyze the characteristics of each of these matrix multiplication algorithms and provide initial heuristics for using the poly-algorithm. All these matrix multiplication algorithms have been tested on the IBM SP2 system, The experimental results are presented in order to demonstrate their relative performance characteristics, motivating the combined value of the taxonomy and new algorithms introduced here. (C) 1997 by John Wiley & Sons, Ltd. C1 MISSISSIPPI STATE UNIV, DEPT COMP SCI, MISSISSIPPI STATE, MS 39762 USA. MISSISSIPPI STATE UNIV, NSF, ENGN RES CTR, MISSISSIPPI STATE, MS 39762 USA. LAWRENCE LIVERMORE NATL LAB, CTR COMPUTAT SCI & ENGN, LIVERMORE, CA 94550 USA. NR 27 TC 8 Z9 8 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1040-3108 J9 CONCURRENCY-PRACT EX JI Concurrency-Pract. Exp. PD MAY PY 1997 VL 9 IS 5 BP 345 EP 389 DI 10.1002/(SICI)1096-9128(199705)9:5<345::AID-CPE258>3.0.CO;2-7 PG 45 WC Computer Science, Software Engineering; Computer Science, Theory & Methods SC Computer Science GA WZ315 UT WOS:A1997WZ31500002 ER PT J AU Ryan, HF Noble, MA Williams, EA Schroeder, WW Pennock, JR Gelfenbaum, G AF Ryan, HF Noble, MA Williams, EA Schroeder, WW Pennock, JR Gelfenbaum, G TI Tidal current shear in a broad, shallow, river-dominated estuary SO CONTINENTAL SHELF RESEARCH LA English DT Article ID STRATIFICATION; SHELF AB Approximately one year of current, temperature, salinity and pressure data were collected at a site near the mouth of the Mobile Bay estuary in Alabama. This estuary is broad, shallow (3 m) and relatively hat. Diurnal tides account for 85% of the current variance in the lower estuary. Tidal currents have significant vertical shear in both amplitude and direction. The principal diurnal constituents in the lower bay, O-1 and K-1, have amplitudes that range from 12 to 25 cm/s in the near-surface layer, 9 to 12 cm/s near the bed. The principal axis of the near-surface diurnal ellipse is rotated 30 degrees clockwise relative to the near-bottom ellipse. This strong tidal current shear can exist because the estuary has a strong, persistent, haline stratification maintained by a continuous river input. The cause and strength of the tidal shear depends on a combination of factors, including differential topographic forcing through separate entrances into the bay and spatial and temporal Variations in water column stability caused by changes in the magnitude of river flow and wind stress. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. UNIV ALABAMA,MARINE ENVIRONM SCI CONSORTIUM,DAUPHIN ISL,AL 36528. US GEOL SURVEY,ST PETERSBURG,FL 33701. RP Ryan, HF (reprint author), US GEOL SURVEY,MENLO PK,CA 92025, USA. NR 24 TC 10 Z9 10 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD MAY PY 1997 VL 17 IS 6 BP 665 EP 688 DI 10.1016/S0278-4343(96)00053-2 PG 24 WC Oceanography SC Oceanography GA WL707 UT WOS:A1997WL70700005 ER PT J AU Covino, BS Bullard, SJ Holcomb, GR Cramer, SD McGill, GE Cryer, CB AF Covino, BS Bullard, SJ Holcomb, GR Cramer, SD McGill, GE Cryer, CB TI Bond strength of electrochemically aged arc-sprayed zinc coatings on concrete SO CORROSION LA English DT Article; Proceedings Paper CT Corrosion 96 CY MAR, 1996 CL DENVER, CO DE adhesion anode; arc-sprayed zinc; bond strength; bridges; cathodic protection; electrochemical impedance spectroscopy; impressed current; interfacial chemistry; reinforced concrete; thermal-sprayed zinc; water permeability AB Research was conducted to determine the effect of electrochemical aging on large-area are-sprayed Zn anodes for cathodic protection (CP) of bridges and other reinforced concrete structures. The study focused on the influences of total charge passed and concrete surface preparation on bonding of Zn to the concrete. Half the samples were preheated prior to being are-sprayed with Zn. The preheated samples had initial bond strengths 80% higher than the unheated samples. This difference became insignificant after = 200 kcoul/m(2) (5.2 A-h/ft(2)). Bond strengths for all samples started to decrease after approximate to 600 kcoul/m(2) (15.5 A-h/ft(2)). Changes in bond strength were correlated with observed changes in permeability of the Zn coating to water electrical behavior of the Zn-concrete interface, charge-transfer resistance, and chemical composition at the Zn-concrete interface. C1 OREGON DEPT TRANSPORTAT,BRIDGE SECT,SALEM,OR 97310. RP Covino, BS (reprint author), US DOE,ALBANY RES CTR,1450 QUEEN AVE,SW,ALBANY,OR 97321, USA. RI Holcomb, Gordon/G-9070-2013 OI Holcomb, Gordon/0000-0003-3542-5319 NR 16 TC 6 Z9 6 U1 0 U2 2 PU NATL ASSN CORROSION ENG PI HOUSTON PA 1440 SOUTH CREEK DRIVE, HOUSTON, TX 77084-4906 SN 0010-9312 J9 CORROSION JI Corrosion PD MAY PY 1997 VL 53 IS 5 BP 399 EP 411 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA XU786 UT WOS:A1997XU78600007 ER PT J AU Heidstra, R Yang, WC Yalcin, Y Peck, S Emons, AM vanKammen, A Bisseling, T AF Heidstra, R Yang, WC Yalcin, Y Peck, S Emons, AM vanKammen, A Bisseling, T TI Ethylene provides positional information on cortical cell division but is not involved in Nod factor-induced root hair tip growth in Rhizobium-legume interaction SO DEVELOPMENT LA English DT Article DE Vicia sativa; pea; Nod factors; root hair deformation; nodulation; ethylene ID PISUM-SATIVUM-L; L CV SPARKLE; LIPO-OLIGOSACCHARIDE SIGNALS; INHIBITOR AMINOETHOXYVINYLGLYCINE; HOST-SPECIFICITY; VICIA-SATIVA; NODULATION; LEGUMINOSARUM; PEA; PROLIFERATION AB Nod factors secreted by Rhizobium leguminosarum bv. viciae induce root hair deformation, involving a reinitiation of tip growth, and the formation of nodule primordia in Vicia sativa (vetch), Ethylene is a potent inhibitor of cortical cell division, an effect that can be counteracted by applying silver ions (Ag+) or aminoethoxy-vinylglycine (AVG), In contrast to the inhibitory effect on cortical cell division, ethylene promotes the formation of root hairs (which involves tip growth) in the root epidermis of Arabidopsis, We investigate the possible paradox concerning the action of ethylene, putatively promoting Nod factor induced tip growth whilst, at the same time, inhibiting cortical cell division. We show by using the ethylene inhibitors AVG and Ag+, that ethylene has no role in the reinitiation of root hair tip growth induced by Nod factors (root hair deformation) in vetch, However, root hair formation is controlled, at least in part, by ethylene, Furthermore, we show that ACC oxidase, which catalizes the fast step in ethylene biosynthesis, is expressed in the cell layers opposite the phloem in that part of the root where nodule primordia are induced upon inoculation with Rhizobium, Therefore, we test whether endogenously produced ethylene provides positional information controlling the site where nodule primordia are formed by determining the position of nodules formed on pea roots grown in the presence of AVG or Ag+. C1 AGR UNIV WAGENINGEN,DEPT MOL BIOL,NL-6703 HA WAGENINGEN,NETHERLANDS. MICHIGAN STATE UNIV,DOE,PLANT RES LAB,E LANSING,MI 48824. AGR UNIV WAGENINGEN,DEPT PLANT CYTOL & MORPHOL,NL-6703 BD WAGENINGEN,NETHERLANDS. RI Bisseling, Ton/A-2421-2013 NR 27 TC 133 Z9 142 U1 0 U2 11 PU COMPANY OF BIOLOGISTS LTD PI CAMBRIDGE PA BIDDER BUILDING CAMBRIDGE COMMERCIAL PARK COWLEY RD, CAMBRIDGE, CAMBS, ENGLAND CB4 4DL SN 0950-1991 J9 DEVELOPMENT JI Development PD MAY PY 1997 VL 124 IS 9 BP 1781 EP 1787 PG 7 WC Developmental Biology SC Developmental Biology GA XB371 UT WOS:A1997XB37100014 PM 9165125 ER PT J AU Stenner, RD Merdink, JL Stevens, DK Springer, DL Bull, RJ AF Stenner, RD Merdink, JL Stevens, DK Springer, DL Bull, RJ TI Enterohepatic recirculation of trichloroethanol glucuronide as a significant source of trichloroacetic acid - Metabolites of trichloroethylene SO DRUG METABOLISM AND DISPOSITION LA English DT Article ID MALE B6C3F1 MOUSE; DICHLOROACETIC ACID; SPECIES-DIFFERENCES; CHLORAL HYDRATE; MICE; CARCINOGENICITY; LIVER AB Trichloroacetic acid (TCA) is a metabolite of trichloroethylene (TRI) thought to contribute to its hepatocarcinogenic effects in mice. Recent studies have shown that peak blood concentrations of TCA do not occur until similar to 12 hr after an oral dose of TRI; however, blood concentrations of TRI reach a maximum within 1 hr and is nondetectable after 2 hr. The objective of this study was to examine quantitatively enterohepatic recirculation of trichloroethanol (TCEOH) and TCA as a possible mechanism responsible for the delayed production of TCA. Jugular vein, duodenum, and bile duct-cannulated Fischer 344 rats were used, with the collection of blood, bile, urine, and feces samples after intraduodenal and intravenous dosing of animals with TRI, TCEOH, and TCA. Samples were analyzed by GC for TCA, total TCEOH, and free TCEOH. The results show that, after an intravenous dose of TCEOH (100 mg/kg), 36% of the TCEOH in brood is attributable to enterohepatic recirculation. With the same treatment, 76% of the TCA in blood is attributable to enterohepatic recirculation of metabolites. Peak concentrations of total TCEOH in bile, after an intraduodenal dose of TRI, are over 5 times higher than peak concentrations of total TCEOH in systemic blood. Peak concentrations of TCEOH glucuronide in bile are similar to 200 times higher than peak concentrations of TCEOH glucuronide in systemic blood. C1 WASHINGTON STATE UNIV, PHARMACOL TOXICOL PROGRAM, PULLMAN, WA 99164 USA. RP Stenner, RD (reprint author), PACIFIC NW LAB, POB 999,MSIN K3-54, RICHLAND, WA 99352 USA. NR 13 TC 19 Z9 19 U1 0 U2 0 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0090-9556 J9 DRUG METAB DISPOS JI Drug Metab. Dispos. PD MAY PY 1997 VL 25 IS 5 BP 529 EP 535 PG 7 WC Pharmacology & Pharmacy SC Pharmacology & Pharmacy GA WZ115 UT WOS:A1997WZ11500001 PM 9152590 ER PT J AU Nishiizumi, K Fink, D Klein, J Middleton, R Masarik, J Reedy, RC Arnold, JR AF Nishiizumi, K Fink, D Klein, J Middleton, R Masarik, J Reedy, RC Arnold, JR TI Depth profile of Ca-41 in an Apollo 15 drill core and the low-energy neutron flux in the Moon SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE cosmogenic nuclide; thermal neutron; production rate; lunar soil ID STONY METEORITES; PRODUCTION-RATES; NUCLIDES; MN-53; CL-36 AB Systematic measurements of the concentrations of cosmogenic Ca-41 (half-life = 1.04 x 10(5) yr) in the Apollo 15 long core 15001-15006 were performed by accelerator mass spectroscopy. Earlier measurements of cosmogenic Be-10, C-14, Al-26, Cl-36, and Mn-53 in the same core have provided confirmation and improvement of theoretical models for predicting production profiles of nuclides by cosmic ray induced spallation in the Moon and large meteorites. Unlike these nuclides, Ca-41 in the lunar surface is produced mainly by thermal neutron capture reactions on Ca-40. The maximum production of Ca-41, about 1 dpm/g Ca, was observed at a depth in the Moon of about 150 g/cm(2). For depths below about 300 g/cm(2), Ca-41 production falls off exponentially with an e-folding length of 175 g/cm(2). Neutron production in the Moon was modeled with the Los Alamos High Energy Transport Code System, and yields of nuclei produced by low-energy thermal and epithermal neutrons were calculated with the Monte Carlo N-Particle code. The new theoretical calculations using these codes are in good agreement with our measured Ca-41 concentrations as well as with Co-60 and direct neutron fluence measurements in the Moon. C1 AUSTRALIAN NUCL SCI & TECHNOL ORG,LUCAS HTS RES LAB,DIV PHYS,MENAI,NSW 2234,AUSTRALIA. UNIV PENN,DEPT PHYS,TANDEM ACCELERATOR LAB,PHILADELPHIA,PA 19104. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV CALIF SAN DIEGO,DEPT CHEM,LA JOLLA,CA 92037. RP Nishiizumi, K (reprint author), UNIV CALIF BERKELEY,SPACE SCI LAB,BERKELEY,CA 94720, USA. RI fink, David/A-9518-2012; OI Reedy, Robert/0000-0002-2189-1303 NR 41 TC 27 Z9 27 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD MAY PY 1997 VL 148 IS 3-4 BP 545 EP 552 DI 10.1016/S0012-821X(97)00051-4 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XE638 UT WOS:A1997XE63800011 ER PT J AU Boissinot, M Karnas, S Lepock, JR Cabelli, DE Tainer, JA Getzoff, ED Hallewell, RA AF Boissinot, M Karnas, S Lepock, JR Cabelli, DE Tainer, JA Getzoff, ED Hallewell, RA TI Function of the Greek key connection analysed using circular permutants of superoxide dismutase SO EMBO JOURNAL LA English DT Article DE amyotrophic lateral sclerosis; beta-barrel; Greek key; permuted; superoxide dismutase ID AMYOTROPHIC-LATERAL-SCLEROSIS; AMYLOID FIBRIL FORMATION; RECOMBINANT HUMAN; PROTEIN-STRUCTURE; FREE CYSTEINES; BETA-BARREL; COPPER; TRANSTHYRETIN; DENATURATION; STABILITY AB Human Cu,Zn superoxide dismutase (SOD) is a single domain all beta-sheet protein with its eight beta-strands arranged as a Greek key beta-barrel or immunoglobulin fold. Three circularly permuted variants of SOD were made by joining the native amino- and carboxy-termini, and introducing new termini at sites originally within connections between beta-strands. The locations of the new termini were chosen to interrupt beta-turns between the two N-terminal beta-hairpins and the short cross-barrel Greek key connection, Expression levels in the Escherichia coli periplasm were indistinguishable from that of native SOD. Reaction rates for the purified proteins were similar to those of the native enzyme, indicating that the permutants are correctly folded, Interrupting the covalent cross-bracing provided by the Greek key connection reduced the stability of the protein by similar to 1.0 kcal/mol, indicating only a slight contribution to conformational stability. The experiments test and eliminate two hypotheses for folding pathways for Greek key beta-barrels that require N-terminal beta-hairpins or covalent attachment across the short Greek key connection. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED, DEPT BIOCHEM, LONDON SW7 2AZ, ENGLAND. SCRIPPS RES INST, DEPT BIOL MOL, LA JOLLA, CA 92037 USA. BROOKHAVEN NATL LAB, DEPT CHEM, UPTON, NY 11973 USA. FU NIGMS NIH HHS [R01 GM 39345, R01 GM 23658, R01 GM 37684]; Wellcome Trust NR 49 TC 25 Z9 27 U1 1 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0261-4189 J9 EMBO J JI Embo J. PD MAY 1 PY 1997 VL 16 IS 9 BP 2171 EP 2178 DI 10.1093/emboj/16.9.2171 PG 8 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA WY677 UT WOS:A1997WY67700001 PM 9171332 ER PT J AU Greening, LA Schipper, L Davis, RE Bell, SR AF Greening, LA Schipper, L Davis, RE Bell, SR TI Prediction of household levels of greenhouse-gas emissions from personal automotive transportation SO ENERGY LA English DT Article ID LIFE-CYCLE; ENERGY USE; GASOLINE; REGION AB The work presented in this paper demonstrates that different subgroups in the population described by various economic and demographic characteristics have different levels of greenhouse gas emissions from personal automotive transportation. Further these characteristics may be assigned a rank or importance in terms of association with emissions levels. And once socioeconomic characteristics of a household are known, emissions levels may be predicted. (C) 1997 Elsevier Science Ltd. C1 AT&T UNIVERSAL CARD SERV,JACKSONVILLE,FL 32256. UNIV ALABAMA,COLL ENGN,DEPT MECH ENGN,TUSCALOOSA,AL 35487. RP Greening, LA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENERGY ANAL PROGRAM,MAILSTOP 90-4000,BERKELEY,CA 94720, USA. NR 32 TC 5 Z9 5 U1 0 U2 4 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 MAY PY 1997 VL 22 IS 5 BP 449 EP 460 DI 10.1016/S0360-5442(96)00152-1 PG 12 WC Thermodynamics; Energy & Fuels SC Thermodynamics; Energy & Fuels GA WK247 UT WOS:A1997WK24700001 ER PT J AU Vairavamurthy, MA Maletic, D Wang, SK Manowitz, B Eglinton, T Lyons, T AF Vairavamurthy, MA Maletic, D Wang, SK Manowitz, B Eglinton, T Lyons, T TI Characterization of sulfur-containing functional groups in sedimentary humic substances by X-ray absorption near-edge structure spectroscopy SO ENERGY & FUELS LA English DT Article; Proceedings Paper CT 212th ACS National Meeting CY AUG 25-29, 1996 CL ORLANDO, FL SP Amer Chem Soc, Div Geochem ID FINE-STRUCTURE SPECTROSCOPY; ORGANIC SULFUR; PETROLEUM ASPHALTENES; MARINE-SEDIMENTS; PERU MARGIN; FORMS; DIAGENESIS; SULFATE; MATTER; COALS AB Humic substances, which are randomly cross-linked heterogeneous organic materials of high molecular weight, comprise a major fraction of the organic matter in soils and sediments. Because humic substances have a variety of functional groups, they play a major role in controlling the physical and chemical characteristics of natural waters, soils, and sediments. Sedimentary humic substances are considered to be the precursors of petroleum-forming kerogens. Sulfur is thought to play a major role in forming humic substances in anoxic marine sediments. Because of their structural heterogeneity, humic substances are not easily amenable to biochemical degradation and, thus, are generally considered to be biologically refractory. The complexity and heterogeneity of humic substances render;the elucidation of their chemical structure a major analytical challenge. Degradative techniques, such as pyrolysis GC-MS, can change a sample's structure during preparation and analysis and, thus, may give inaccurate. information. In this study, we investigated the sulfur-containing functional groups in humic acids from various marine sediments using XANES spectroscopy which has proved to be an important, nondestructive tool for analyzing sulfur forms. Humic acids were isolated from near-surface sediments from three locations: a salt marsh in Shelter Island, NY; the Peru Margin; and Florida Bay. We found that organic sulfides, di- and polysulfides, sulfonates, and organic sulfates are the major forms of sulfur in these sedimentary humics. The reduced-sulfur structures, organic sulfides, and di- and polysulfides, are essentially intramolecular as apposed to the highly oxidized forms of sulfur, sulfonates, and ester-bonded sulfates, which can only be present as end groups. The abundance of the reduced-sulfur structures reflects the extent to which sulfur is involved in forming intramolecular cross-links which are crucial for building up the macromolecular structures of humic substances. The significance of the presence of the different sulfur functionalities in humic substances is discussed in relation re, early diagenesis and preservation of organic matter in marine sediments. C1 WOODS HOLE OCEANOG INST,DEPT MARINE CHEM & GEOCHEM,WOODS HOLE,MA 02543. UNIV MISSOURI,DEPT GEOL,COLUMBIA,MO 65211. RP Vairavamurthy, MA (reprint author), BROOKHAVEN NATL LAB,DEPT APPL SCI,GEOCHEM PROGRAM,BLDG 801,UPTON,NY 11973, USA. NR 54 TC 71 Z9 77 U1 4 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAY-JUN PY 1997 VL 11 IS 3 BP 546 EP 553 DI 10.1021/ef960212a PG 8 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XA830 UT WOS:A1997XA83000006 ER PT J AU Thompson, RL Rothenberger, KS Retcofsky, HL AF Thompson, RL Rothenberger, KS Retcofsky, HL TI Variable-temperature EPR studies of Illinois No 6 coal treated with donor and acceptor molecules SO ENERGY & FUELS LA English DT Article ID ELECTRON-PARAMAGNETIC-RES; BITUMINOUS COAL; CHARGE-TRANSFER; COMPLEXES; RADICALS; SPECTRUM AB Variable-temperature EPR studies of Illinois No. 6 coal, its pyridine extract, and samples of each after treatment with known donor and acceptor molecules are reported. The purpose of the study was to explore the origin of the EPR signals near g = 2 and to elucidate the nature of noncovalently bonded interactions in coal. Curie Law behavior is exhibited for each sample, indicating that the EPR signals are dominated by doublet state species. No evidence for thermally accessible, low-lying triplet states, such as those found in some charge-transfer complexes, was found. Infrared spectroscopy suggests, however, that electron transfer from the coal does occur after treatment with electron accepters such as TCNQ and TCNE. EPR studies of the Illinois No. 6 coal samples after treatment with the known electron donor TTF revealed the formation of the TTF radical cation. C1 PARSONS POWER GRP INC,LIBRARY,PA 15129. US DOE,FED ENERGY TECHNOL CTR,PITTSBURGH,PA 15236. BURNS & ROE SERV CORP,PITTSBURGH,PA 15236. NR 43 TC 7 Z9 8 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0887-0624 J9 ENERG FUEL JI Energy Fuels PD MAY-JUN PY 1997 VL 11 IS 3 BP 739 EP 746 DI 10.1021/ef970006i PG 8 WC Energy & Fuels; Engineering, Chemical SC Energy & Fuels; Engineering GA XA830 UT WOS:A1997XA83000033 ER PT J AU Tokunaga, TK Brown, GE Pickering, IJ Sutton, SR Bait, S AF Tokunaga, TK Brown, GE Pickering, IJ Sutton, SR Bait, S TI Selenium redox reactions and transport between ponded waters and sediments SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID X-RAY-ABSORPTION; NEAR-EDGE STRUCTURE; KESTERSON RESERVOIR; FLUORESCENCE MICROPROBE; GROUNDWATER CONTAMINATION; SELENATE REDUCTION; ELEMENTAL SELENIUM; MODEL COMPOUNDS; SOIL; SPECTROSCOPY AB Understanding the cycling of trace elements such as selenium in the environment requires information on mass transfer and reactions occurring across boundaries. Selenium partitioning and redox transformations in ponded laboratory sediments was compared with a model based on the transport of Se(VI) and Se(IV) between surface waters and sediment pore waters. Waters containing Se(VI) were ponded over initially nonseleniferous sediment columns. X-ray absorption spectroscopy demonstrated Se reduction to Se(O) in these sediments. Synchrotron X-ray microprobe analyses revealed very high Se concentrations within millimeters of the sediment surface. Concentrations of Se(VI) and Se(IV) in sediment pore waters were used as time-dependent boundary conditions to model concentrations of these species in overlying pool waters. Two parameters, the mass transfer coefficient and pool Se(VI) apparent reduction rate constant, were optimized. The successful application of mass transfer coefficients in this study resulted from Se reduction rates within very shallow boundary zones being proportional to Se concentration gradients acting across these zones, rather than solely representing diffusion across these zones. The large gradients in Se concentrations observed in these sediment columns indicate that experimental methods with spatial resolution finer than 1 mm are needed before mechanistic diffusion-redox analyses can be successfully applied to these types of systems. C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,STANFORD,CA 94309. UNIV CHICAGO,DEPT GEOPHYS SCI,CHICAGO,IL 60637. UNIV CHICAGO,CONSORTIUM ADV RADIAT SOURCES,CHICAGO,IL 60637. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. RP Tokunaga, TK (reprint author), UNIV CALIF BERKELEY,EO LAWRENCE BERKELEY NATL LAB,DIV EARTH SCI,1 CYCLOTRON RD,BERKELEY,CA 94720, USA. RI Schneider, Larissa/C-9863-2012; Tokunaga, Tetsu/H-2790-2014; Pickering, Ingrid/A-4547-2013; OI Tokunaga, Tetsu/0000-0003-0861-6128; Pickering, Ingrid/0000-0002-0936-2994 NR 63 TC 38 Z9 39 U1 1 U2 16 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 MAY PY 1997 VL 31 IS 5 BP 1419 EP 1425 DI 10.1021/es960665u PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WW948 UT WOS:A1997WW94800040 ER PT J AU Conrad, ME Daley, PF Fischer, ML Buchanan, BB Leighton, T Kashgarian, M AF Conrad, ME Daley, PF Fischer, ML Buchanan, BB Leighton, T Kashgarian, M TI Combined C-14 and delta C-13 monitoring of in situ biodegradation of petroleum hydrocarbons SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID INSITU BIODEGRADATION; CONTAMINATED AQUIFER; CARBON ISOTOPE; SOIL; DEGRADATION; GROUNDWATER; ZONE AB Measurements of the stable carbon isotope ratios (delta(13)C) of microbial metabolic end products presents a promising method for monitoring in situ bioremediation of petroleum hydrocarbons. Differences between the delta(13)C values of hydrocarbons and indigenous carbon sources (e.g., plant matter, soil carbonates) can be exploited to trace the origins of metabolic end products. However, in zones of methanogenesis and/or where the delta(13)C values of endogenous plant matter overlap those of hydrocarbons, delta(13)C measurements can produce ambiguous results. In such cases, simultaneous measurement of the radiocarbon (C-14) contents of metabolic end products can be used to determine their sources. This method was applied at a gasoline station spill site where hydrocarbons were the only source of C-14-free carbon. Combined delta(13)C and C-14 measurements of soil gas CO2 and dissolved inorganic carbon in groundwater enabled quantification of carbon inputs. Furthermore, low C-14 contents of high delta(13)C CO2 were crucial in establishing that the soil gas CO2 was derived from methanogenesis of hydrocarbons and not shell dissolution. In addition, low C-14 content coupled with a 16 parts per thousand drop in the delta(13)C values of CO2 across a semipermeable layer beneath the gas station building confirmed that microbial oxidation of methane was occurring within this zone. C1 LAWRENCE LIVERMORE NATL LAB,ENVIRONM RESTORAT DIV,LIVERMORE,CA 94550. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV ENERGY & ENVIRONM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT PLANT & MICROBIAL BIOL,BERKELEY,CA 94720. UNIV CALIF BERKELEY,DEPT MOL & CELL BIOL,BERKELEY,CA 94720. LAWRENCE LIVERMORE NATL LAB,CTR ACCELERATOR MASS SPECTROMETRY,LIVERMORE,CA 94550. RP Conrad, ME (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DEPT EARTH SCI,MS 70A-3363,BERKELEY,CA 94720, USA. RI Conrad, Mark/G-2767-2010; Kashgarian, Michaele/E-1665-2011 OI Kashgarian, Michaele/0000-0001-7824-8418 NR 34 TC 51 Z9 52 U1 0 U2 13 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 MAY PY 1997 VL 31 IS 5 BP 1463 EP 1469 DI 10.1021/es9607143 PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WW948 UT WOS:A1997WW94800046 ER PT J AU Peterson, ML White, AF Brown, GE Parks, GA AF Peterson, ML White, AF Brown, GE Parks, GA TI Surface passivation of magnetite by reaction with aqueous Cr(VI): XAFS and TEM results SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID X-RAY-ABSORPTION; NEAR-EDGE STRUCTURE; SPECTROSCOPY; CR(III) C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. STANFORD SYNCHROTRON RADIAT LAB, STANFORD, CA 94309 USA. RP STANFORD UNIV, DEPT GEOG & ENVIRONM SCI, STANFORD, CA 94305 USA. NR 24 TC 111 Z9 113 U1 3 U2 33 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY PY 1997 VL 31 IS 5 BP 1573 EP 1576 DI 10.1021/es960868i PG 4 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WW948 UT WOS:A1997WW94800061 ER PT J AU Meier, JR Chang, LW Jacobs, S Torsella, J Meckes, MC Smith, MK AF Meier, JR Chang, LW Jacobs, S Torsella, J Meckes, MC Smith, MK TI Use of plant and earthworm bioassays to evaluate remediation of soil from a site contaminated with polychlorinated biphenyls SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE polychlorinated biphenyls; phytotoxicity; earthworms; genotoxicity; Isopropanol ID ANAPHASE-TELOPHASE TEST; EISENIA-FETIDA; SUBLETHAL CONCENTRATIONS; COMPARATIVE TOXICITY; ORGANIC-CHEMICALS; MICRONUCLEUS TEST; HEAVY-METALS; GENOTOXICITY; REPRODUCTION; BIOREMEDIATION AB Soil from a site heavily contaminated with polychlorinated biphenyls (PCBs) was treated with a pilot-scale, solvent extraction technology. Bioassays in earthworms and plants were used to examine the efficacy of the remediation process for reducing the toxicity of the soil. The earthworm toxicity bioassays were the 14-d survival test and 21-d reproduction test, using Lumbricus terrestris and Eisenia fetida andrei. The plant bioassays included phytotoxicity tests for seed germination and root elongation in lettuce and oats, and a genotoxicity test (anaphase aberrations) in Allium cepa (common onion). Although the PCB content of the soil was reduced by 99% (below the remediation goal), toxicity to earthworm reproduction remained essentially unchanged following remediation. Furthermore, phytotoxicity and genotoxicity were higher for the remediated soil compared to the untreated soil. The toxicity remaining after treatment appeared to be due to residual solvent introduced during the remediation process, and/or to heavy metals or other inorganic contaminants not removed by the treatment. Mixture studies involving isopropanol and known toxicants indicated possible synergistic effects of the extraction solvent and soil contaminants. The toxicity in plants was essentially eliminated by a postremediation, water-rinsing step. These results demonstrate a need for including toxicity measurements in the evaluation of technologies used in hazardous waste site remediations, and illustrate the potential value of such measurements for making modifications to remediation processes. C1 DYNCORP, CINCINNATI, OH 45268 USA. OAK RIDGE INST SCI & EDUC, CINCINNATI, OH 45268 USA. US EPA, NATL RISK MANAGEMENT RES LAB, CINCINNATI, OH 45268 USA. RP Meier, JR (reprint author), US EPA, NATL EXPOSURE RES LAB, CINCINNATI, OH 45268 USA. NR 42 TC 35 Z9 36 U1 1 U2 13 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD MAY PY 1997 VL 16 IS 5 BP 928 EP 938 DI 10.1897/1551-5028(1997)016<0928:UOPAEB>2.3.CO;2 PG 11 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WX065 UT WOS:A1997WX06500012 ER PT J AU Schultz, IR Newman, MC AF Schultz, IR Newman, MC TI Methyl mercury toxicokinetics in channel catfish (Ictalurus punctatus) and largemouth bass (Micropterus salmoides) after intravascular administration SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE methyl mercury; toxicokinetics; catfish; bass; plasma binding ID RAINBOW-TROUT; FISH CONSUMPTION; CARDIAC-OUTPUT; TISSUE UPTAKE; BLOOD-FLOW; METHYLMERCURY; GAIRDNERI; ACCUMULATION; WATER; FOOD AB We compared the differences in the distribution and elimination of CH3Hg after intraarterial injection and serial blood removal in catfish and bass of similar body size under consistent water quality conditions. The blood and plasma concentration-time profiles of individual fish were analyzed using a three-compartment, clearance-volume model. The plasma protein binding of CH3Hg was determined by ultrafiltration (30,000 mel. wt. cutoff) and the binding affinity (p) of CH3Hg for red blood cells (RBCs) was also calculated. Toxicokinetic analysis of the plasma concentration-time profiles provided the following values: apparent volume of distribution at steady state (V-ss) = 30 +/- 14 ml/g (catfish), 6.2 +/- 2 ml/g (bass); total body clearance (C-0) = 0.026 +/- 0.011 ml/h/g (catfish), 0.0057 +/- 0.001 ml/h/g (bass). The values of V-ss and Cl-0 estimated from the blood concentration-time profiles in catfish and bass were fivefold lower. The elimination half-life from blood and plasma was between 814 and 1670 h and was not statistically different between species or reference fluid. The AUG(0-->x) for blood was over three times higher than plasma, due to the binding of CH3Hg to RBCs. The unbound fraction of CH3Hg in bass plasma was 14-fold lower (0.25 vs. 3.64%) and the p for RBCs was 20 times greater than catfish (5,974 vs. 289). The decreased binding to plasma and RBCs in catfish is consistent with the increased extravascular distribution and clearance capacity of CH3Hg in catfish because a larger fraction of the CH3Hg in blood is available to distribute outside the vascular system. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, AIKEN, SC 29802 USA. NR 49 TC 17 Z9 18 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD MAY PY 1997 VL 16 IS 5 BP 990 EP 996 DI 10.1897/1551-5028(1997)016<0990:MMTICC>2.3.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WX065 UT WOS:A1997WX06500018 ER PT J AU Schultz, IR Hayton, WL AF Schultz, IR Hayton, WL TI Influence of body fat on trifluralin toxicokinetics in rainbow trout (Oncorhynchus mykiss) SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE trifluralin; toxicokinetics; trout; lipid; fat ID BIOCONCENTRATION; FISH AB We previously characterized the toxicokinetics of trifluralin (TF) in rainbow trout (Oncorhynchus mykiss) and found a large steady state volume of distribution (V-ss) that was attributed to a large, poorly perfused peripheral storage compartment. Because adipose tissue was expected to be an important peripheral storage tissue for this lipophilic herbicide, we studied its toxicokinetics in trout that differed in body fat content. Large, hatchery-reared rainbow trout and adult summer-run steelhead trout were fitted with an aortic cannula and given a 1-mg/kg dose of TE The steelhead were studied approximately 3 weeks prior to spawning and after a 9-month fasting period. The total lipid content of the steelhead after removal of the reproductive organs averaged 1.2% of body weight, whereas that of the hatchery trout was 8%. Toxicokinetic analysis of the plasma concentration-time profile using a three-compartment model found the V-ss in steelhead to be reduced significantly (p < 0.01) compared with the hatchery trout(1.3 vs. 5.7 L/kg). Other parameters that differed were the maximum plasma concentration, which was higher in steelhead (p < 0.05), and mean residence time, which were reduced (p < 0.05) in steelhead. Although several physiological and the elimination t(1/2,beta) factors are probably involved, examination of the relationship between V-ss and lipid content supported the hypothesis that the distribution of TF in trout was largely influenced by the lipid content of the fish. C1 OHIO STATE UNIV,COLL PHARM,COLUMBUS,OH 43210. RP Schultz, IR (reprint author), BATTELLE PNNL,DIV MOL BIOSCI,POB 999-97-56,RICHLAND,WA 99352, USA. NR 25 TC 10 Z9 12 U1 3 U2 4 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 MAY PY 1997 VL 16 IS 5 BP 997 EP 1001 DI 10.1897/1551-5028(1997)016<0997:IOBFOT>2.3.CO;2 PG 5 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA WX065 UT WOS:A1997WX06500019 ER PT J AU Esposito, F Cuccovillo, F Vanoni, M Cimino, F Anderson, CW Appella, E Russo, T AF Esposito, F Cuccovillo, F Vanoni, M Cimino, F Anderson, CW Appella, E Russo, T TI Redox-mediated regulation of p21(waf1/cip1) expression involves a post-transcriptional mechanism and activation of the mitogen-activated protein kinase pathway SO EUROPEAN JOURNAL OF BIOCHEMISTRY LA English DT Article DE p53; p21(waf1/cip1); mitogen-activated protein kinase; reactive oxygen species ID NIH 3T3 CELLS; P53-INDEPENDENT PATHWAY; SIGNAL-TRANSDUCTION; HUMAN-FIBROBLASTS; MESSENGER-RNA; FREE-RADICALS; INDUCTION; GROWTH; WAF1; P21 AB p21(waf1/cip1) gene expression is induced by DNA damage in cells with wild-type p53 and contributes to the arrest of cell growth. It was demonstrated that under many experimental conditions, including oxidative stress, p21(waf1/cip1) expression can be induced through p53 independent pathways. Since most of these experimental conditions induce the phosphorylation of mitogen-activated protein kinase (MAPK) and thus its activation, we evaluated p21(waf1/cip1) mRNA levels in cells exposed to an oxidative stress, induced by diethylmaleate (Et(2)Mal), and in which the MAPK pathway was blocked. The expression of a dominant-negative mutant of MEK, the MAPK kinase that phosphorylates and activates MAPK, and of a dominant-negative [Asn17]Ras mutant prevented the Et(2)Mal-induced accumulation of p21(waf1/cip1) mRNA. Similarly, the expression of MEK- and of [Asn17]Ras mutants decreased the 12-O-tetradecanoyl-phorbol 13-acetate (TPA)-mediated p21(waf1/cip1) induction. Furthermore, TPA-induced and serum-induced p21(waf1/cip1) mRNA accumulation was blocked by pretreating the cells with the antioxidant compound N-acetylcysteine, suggesting that oxidative stress is involved in these responses. p21(waf1/cip1) mRNA levels reached a maximum within 2 h of adding Et(2)Mal or TPA; however, the rate of transcription from a p21(waf1/cip1)-promoter construct did not increase during this period. In contrast, cells treated with actinomycin D show an increase of p21(waf1/cip1) mRNA stability after Et(2)Mal treatment. This result suggests that the increase in p21(waf1/cip1) mRNA at early times results from post-transcriptional regulatory events. Longer exposure to TPA may activate p21(waf1/cip1) gene transcription through an Sp1-dependent mechanism, while Et(2)Mal treatment gradually inhibits p21(waf1/cip1) gene transcription through oxidative changes that affect Sp1 binding to DNA. C1 UNIV NAPLES,DIPARTIMENTO BIOCHIM & BIOTECNOL MED,I-80131 NAPLES,ITALY. UNIV MILAN,DIPARTIMENTO FISIOL & BIOCHIM GEN,MILAN,ITALY. BROOKHAVEN NATL LAB,DEPT BIOL,UPTON,NY 11973. NCI,CELL BIOL LAB,NIH,BETHESDA,MD 20892. RI Russo, Tommaso/K-1331-2016; Esposito, Franca/K-2024-2016 OI Russo, Tommaso/0000-0003-4426-0106; Esposito, Franca/0000-0001-9340-6875 NR 41 TC 93 Z9 94 U1 0 U2 6 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0014-2956 J9 EUR J BIOCHEM JI Eur. J. Biochem. PD MAY 1 PY 1997 VL 245 IS 3 BP 730 EP 737 DI 10.1111/j.1432-1033.1997.00730.x PG 8 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA WY448 UT WOS:A1997WY44800027 PM 9183012 ER PT J AU Economos, CD Nelson, ME Fiatarone, MA Dallal, GE Heymsfield, SB Wang, J Yasumara, S Ma, R Vaswani, AN RussellAulet, M Pierson, RN AF Economos, CD Nelson, ME Fiatarone, MA Dallal, GE Heymsfield, SB Wang, J Yasumara, S Ma, R Vaswani, AN RussellAulet, M Pierson, RN TI A multi-center comparison of dual energy X-ray absorptiometers: In vivo and in vitro soft tissue measurement SO EUROPEAN JOURNAL OF CLINICAL NUTRITION LA English DT Article DE dual energy X-ray absorptiometry; DXA; densitometry; body composition; lean mass; fat mass ID LEAN BODY-MASS; PHOTON-ABSORPTIOMETRY; POSTMENOPAUSAL WOMEN; BONE DENSITOMETER; FAT; PRECISION; INVIVO; PERFORMANCE; DEXA; HYDRODENSITOMETRY AB Objective: To assess intra- and inter-site soft tissue variability by dual energy X-ray absorptiometry (DXA). Design: Cross-sectional trial. Setting: Three medical research institutions. Subjects: Five humans (in vivo) and four phantoms (in vitro), configured from two whole body phantoms with artificial skeletons and thickness overlays. Interventions: Duplicate total-body DXA scans were performed on all subjects at each institution within a 15 d period. Results: All intra-site coefficients of variation (CV) were < 0.5% for total tissue mass, but in vitro and in vivo Cvs were 7.2% and 2.3% for fat mass (FM) and 2.5% and 0.9% for lean mass (LM), respectively. Several total-body and regional FM and LM measurements were significantly different between sites (P < 0.05), with percent differences between sites ranging from 2.6-13.3% for FM and from 1.6-13.6% for LM. Site 2 was consistently lower for FM and Site 3 was consistently lower for LM. Conclusions: These results stress the need for both rigorous and standardized cross-calibration procedures for soft tissue measurement by DXA. C1 TUFTS UNIV,JEAN MAYER USDA,HUMAN NUTR RES CTR AGING,BOSTON,MA 02111. ST LUKES ROOSEVELT HOSP,BODY COMPOSIT UNIT,NEW YORK,NY 10025. BROOKHAVEN NATL LAB,UPTON,NY 11973. WINTHROP UNIV HOSP,OSTEOPOROSIS RES CLIN,MINEOLA,NY 11501. UNIV MICHIGAN,ANN ARBOR,MI 48109. FU NIA NIH HHS [T32AG00209]; NIDDK NIH HHS [P01-DK42618] NR 47 TC 35 Z9 35 U1 1 U2 2 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE, HAMPSHIRE, ENGLAND RG21 6XS SN 0954-3007 J9 EUR J CLIN NUTR JI Eur. J. Clin. Nutr. PD MAY PY 1997 VL 51 IS 5 BP 312 EP 317 DI 10.1038/sj.ejcn.1600400 PG 6 WC Nutrition & Dietetics SC Nutrition & Dietetics GA WX718 UT WOS:A1997WX71800006 PM 9152682 ER PT J AU Strijckmans, V Bottlaender, M Luo, HM Ottaviani, M McPherson, DW Loch, C Fuseau, C Knapp, FF Maziere, B AF Strijckmans, V Bottlaender, M Luo, HM Ottaviani, M McPherson, DW Loch, C Fuseau, C Knapp, FF Maziere, B TI Positron emission tomographic investigations of central muscarinic cholinergic receptors with three isomers of [Br-76]BrQNP SO EUROPEAN JOURNAL OF NUCLEAR MEDICINE LA English DT Article DE [Br-76]BrQNP; muscarinic receptors; positron emission tomography; radioligands ID IODINE-125-LABELED 1-AZABICYCLO<2.2.2>OCT-3-YL ALPHA-HYDROXY-ALPHA-(1-IODO-1-PRO; HUMAN-MEMORY; BRAIN; BIODISTRIBUTION; BABOONS; SYSTEM; LIGAND AB We studied the potential of three radiobrominated isomers of BrQNP, (Z(-,-)-[Br-76]BrQNP, E(-,-)[Br-76]BrQNP and E(-,+)-[Br-76]BrQNP), as suitable radioligands for imaging of central muscarinic cholinergic receptors in the human brain. These radioligands were stereospecifically prepared by electrophilic radiobromodestannylation of the respective tributylstannyl precursors using no-carrier-added [Br-76]BrNH4 and peracetic acid. Preliminary pharmacological characterizations were determined by biodistribution, autoradiography, competition, displacement and metabolite studies in rats. The (-,-)-configuration presented important specific uptakes in brain muscarinic cholinergic receptor (mAChR)-rich structures and in heart, low metabolization rates and an apparent M-2 selectivity. The (-,+)-configuration revealed more rapid clearance, lower uptake, a higher metabolization rate and an apparent M-1 selectivity. Reversibility of the binding was confirmed for the three radiotracers. Positron emission tomography in the living baboon brain revealed high and rapid uptake in the brain and accumulation in the mAChR-rich structures studied. At 30 min p.i., the E(-,-)-radiotracer reached a plateau in cortex, pens and thalamus with concentrations of 29%, 24% and 19% respectively. [Br-76]BrQNP also accumulated in these structures, reaching a maximal uptake (27% ID/1) in the cortex 2 h p.i. At 5 min p.i. a plateau (17% ID/1) was only observed in the cortex for the E(-,+)-[Br-76]BrQNP; by contrast, the other structures showed slow washout. After 3 weeks, the (-,-)-radiotracers were studied in the same baboon pretreated with dexetimide (1 mg/kg), a well-known muscarinic antagonist. In all the mAChR structures, the highly reduced uptake observed after this preloading step indicates that these radiotracers specifically bind to muscarinic receptors. Z(-,-)-[Br-76]BrQNP, which is displaced in higher amounts from M-2 mAChR-enriched structures, reveals an M-2 affinity. The two isomers having the (-,-)-configuration are potential probes for investigating central muscarinic receptors. The absolute configuration on the acetate chiral centre influences their muscarinic subtype selectivity and the cis-trans isomerism of the vinyl moiety affects their specific fixation. C1 CEA,SERV HOSP FREDERIC JOLIOT,DRM,F-91406 ORSAY,FRANCE. OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. NR 17 TC 4 Z9 5 U1 0 U2 0 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0340-6997 J9 EUR J NUCL MED JI Eur. J. Nucl. Med. PD MAY PY 1997 VL 24 IS 5 BP 475 EP 482 PG 8 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA XA985 UT WOS:A1997XA98500002 PM 9142726 ER PT J AU Salmon, CP Knize, MG Felton, JS AF Salmon, CP Knize, MG Felton, JS TI Effects of marinating on heterocyclic amine carcinogen formation in grilled chicken SO FOOD AND CHEMICAL TOXICOLOGY LA English DT Article ID FRIED BEEF PATTIES; AROMATIC-AMINES; FOOD-PRODUCTS; MODEL SYSTEM; MUTAGENS; COOKING; ACIDS; MEAT; PHIP; CREATININE AB This study compared heterocyclic aromatic amines in marinated and unmarinated chicken breast meat flame-broiled on a propane grill. Chicken was marinated prior to grilling and the levels of several heterocyclic amines formed during cooking were determined by solid-phase extraction and HPLC. Compared with unmarinated controls, a 92-99% decrease in 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was observed in whole chicken breast marinated with a mixture of brown sugar, olive oil, cider vinegar, garlic, mustard, lemon juice and salt, then grilled for 10, 20, 30 or 40 min. Conversely, 2-amino-3, 8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) increased over 10-fold with marinating, but only at the 30 and 40 min cooking times. Marinating reduced the total detectable heterocyclic amines from 56 to 1.7 ng/g, from 158 to 10 ng/g and from 330 to 44 ng/g for grilling times of 20, 30 and 40 min, respectively. The mutagenic activity of the sample extracts was also measured, using the Ames/Salmonella assay. Mutagenic activity was lower in marinated samples cooked for 10, 20 and 30 min, but higher in the marinated samples cooked for 40 min, compared with unmarinated controls. Although a change in free amino acids, which are heterocyclic amine precursors, might explain the decrease in PhIP and increase in MeIQx, no such change was detected. Marinating chicken in one ingredient at a time showed that sugar was involved in the increased MeIQx, but the reason for the decrease in PhIP was unclear. PhIP decreased in grilled chicken after marinating with several individual ingredients. This work shows that marinating is one method that can significantly reduce PhIP concentration in grilled chicken. (C) 1997 Elsevier Science Ltd. C1 LAWRENCE LIVERMORE NATL LAB,BIOL & BIOTECHNOL RES PROGRAM,LIVERMORE,CA 94551. FU NCI NIH HHS [P01 CA55861] NR 29 TC 105 Z9 109 U1 0 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-6915 J9 FOOD CHEM TOXICOL JI Food Chem. Toxicol. PD MAY PY 1997 VL 35 IS 5 BP 433 EP 441 DI 10.1016/S0278-6915(97)00020-3 PG 9 WC Food Science & Technology; Toxicology SC Food Science & Technology; Toxicology GA XH494 UT WOS:A1997XH49400001 PM 9216741 ER PT J AU Woodworth, JG Meier, WR AF Woodworth, JG Meier, WR TI Target production for inertial fusion energy SO FUSION TECHNOLOGY LA English DT Article ID DESIGN AB Inertial fusion energy (IFE) power plants will require the ignition and burn of five to ten fusion fuel targets every second. The technology to economically mass produce high-quality precision targets at this rate is beyond the current state of the art. Techniques that are scalable to high production rates, however have been identified for all the necessary process steps, and many have been tested in laboratory experiments or are similar to current commercial manufacturing processes. A baseline target factory conceptual design is described, and its capital and operating costs are estimated. The result is a total production cost of similar to 16c/target. At this level, target production represents similar to 6% of the estimated cost of electricity from a 1-GW(electric) IFE power plant. Cost scaling relationships are presented and used to show the variation in target cost with production rate and plant power levels. RP Woodworth, JG (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94551, USA. NR 23 TC 3 Z9 3 U1 1 U2 1 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD MAY PY 1997 VL 31 IS 3 BP 280 EP 290 PG 11 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WW878 UT WOS:A1997WW87800003 ER PT J AU Colchin, RJ Galambos, JD Goranson, PL Hirshman, SP Edmonds, PH Uglum, JR AF Colchin, RJ Galambos, JD Goranson, PL Hirshman, SP Edmonds, PH Uglum, JR TI The design of the center core of a spherical tokamak SO FUSION TECHNOLOGY LA English DT Article AB Recently, there have been several proposals to build low-aspect-ratio or spherical tokamaks with plasma currents in the range of 1 MA. These low-aspect-ratio tokamaks employ conventional engineering, except in the central core, which contains the central toroidal field conductors and an ohmic heating solenoid (if present). To achieve low aspect ratios, these components must be engineered to the limits of stress and thermal properties. Solutions are found for the steady-state cooling of the toroidal field conductors. The solenoid, which must be high performance to produce the flux swing required for a I-MA plasma current, cannot be cooled steady state. The mathematics and procedures necessary to study these issues are given. C1 UNIV TEXAS,FUS RES CTR,AUSTIN,TX 78712. RP Colchin, RJ (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. RI Edmonds, Phillip/A-1336-2009 NR 26 TC 8 Z9 9 U1 0 U2 0 PU AMER NUCLEAR SOCIETY PI LA GRANGE PK PA 555 N KENSINGTON AVENUE, LA GRANGE PK, IL 60525 SN 0748-1896 J9 FUSION TECHNOL JI Fusion Technol. PD MAY PY 1997 VL 31 IS 3 BP 350 EP 369 PG 20 WC Nuclear Science & Technology SC Nuclear Science & Technology GA WW878 UT WOS:A1997WW87800010 ER PT J AU Frazer, KA Ueda, Y Zhu, YW Gifford, VR Garofalo, MR Mohandas, N Martin, CH Palazzolo, MJ Cheng, JF Rubin, EM AF Frazer, KA Ueda, Y Zhu, YW Gifford, VR Garofalo, MR Mohandas, N Martin, CH Palazzolo, MJ Cheng, JF Rubin, EM TI Computational and biological analysis of 680 kb of DNA sequence from the human 5q31 cytokine gene cluster region SO GENOME RESEARCH LA English DT Article ID TRANSGENIC MICE; XENOPUS-LAEVIS; EXPRESSION; CLONING; PROTEIN; HYPERRESPONSIVENESS; DROSOPHILA; LINKAGE; FAMILY; ASTHMA AB With the human genome project advancing into what will be a 7- to 10-year DNA sequencing phase, we are presented with the challenge of developing strategies to convert genomic sequence data, as they become available, into biologically meaningful information. We have analyzed 680 kb of noncontiguous DNA sequence from a 1-Mb region of human chromosome 5q31, coupling computational analysis with gene expression studies of tissues isolated from humans as well as from mice containing human YAC transgenes. This genomic interval has been noted previously for containing the cytokine gene cluster and a quantitative trait locus associated with inflammatory diseases. Our analysis identified and verified expression of 16 new genes, as well as 7 previously known genes. Of the total of 23 genes in this region, 78% had similarity matches to sequences in protein databases and 83% had exact expressed sequence tag [EST] database matches. Comparative mapping studies of eight of the new human genes discovered in the 5q31 region revealed chat all are located in the syntenic region of mouse chromosome 11q. Our analysis demonstrates an approach For examining human sequence as it is made available from large sequencing programs and has resulted in the discovery of several biomedically important genes, including a cyclin, a transcription factor that is homologous to an oncogene, a protein involved in DNA repair, and several new members of a family of transporter proteins. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,CTR HUMAN GENOME,BERKELEY,CA 94720. FU NHLBI NIH HHS [PPG HL18574] NR 44 TC 101 Z9 101 U1 0 U2 1 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 1054-9803 J9 GENOME RES JI Genome Res. PD MAY PY 1997 VL 7 IS 5 BP 495 EP 512 PG 18 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA WX931 UT WOS:A1997WX93100010 PM 9149945 ER PT J AU Kim, J Ashworth, L Branscomb, E Stubbs, L AF Kim, J Ashworth, L Branscomb, E Stubbs, L TI The human homolog of a mouse-imprinted gene, Peg3, maps to a zinc finger gene-rich region of human chromosome 19q13.4 SO GENOME RESEARCH LA English DT Letter ID SITU HYBRIDIZATION MAP; PRADER-WILLI AB Peg3 (paternally expressed gene 3) is the first imprinted gene detected in the proximal region of mouse chromosome 7. Because imprinting is a trait that is generally conserved among mammals, and imprinted domains generally encompass several adjacent genes, expression patterns and chromosomal environment of the human counterpart of Peg3 are of special interest. In this study we have localized human PEG3 similar to 2 Mb proximal of the telomere of chromosome 19q, within a region known to carry large numbers of tandemly clustered Kruppel-type zinc finger-containing (ZNF) genes. Peg3 also encodes a Kruppel-type ZNF protein but one that is distinguished from other ZNF gene products by the fact that it carries two novel proline-rich motifs. Comparison between mouse Peg3 and partial human PEG3 gene sequences revealed a high level of conservation between the two species, despite the fact that one of the two proline-rich repeats is absent from the human gene. Our data demonstrate that the human gene is expressed at highest levels in ovary and placenta; mouse Peg3, by contrast, is transcribed at highest levels in the adult brain. These comparative mapping, sequencing, and expression data provide the fil st clues to the potential activities of PEG3, and generate new tools to aid in the analysis of structure and function of a potentially new imprinted domain located in human chromosome 19q13.4 and mouse chromosome 7. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94551. OI Stubbs, Lisa/0000-0002-9556-1972 NR 32 TC 70 Z9 73 U1 0 U2 1 PU COLD SPRING HARBOR LAB PRESS PI PLAINVIEW PA 1 BUNGTOWN RD, PLAINVIEW, NY 11724 SN 1054-9803 J9 GENOME RES JI Genome Res. PD MAY PY 1997 VL 7 IS 5 BP 532 EP 540 PG 9 WC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity SC Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology; Genetics & Heredity GA WX931 UT WOS:A1997WX93100013 PM 9149948 ER PT J AU Lin, HH Stubbs, LJ Mucenski, ML AF Lin, HH Stubbs, LJ Mucenski, ML TI Identification and characterization of a seven transmembrane hormone receptor using differential display SO GENOMICS LA English DT Article ID C-MYB; MONOCLONAL-ANTIBODY; HEMATOPOIETIC-CELLS; MESSENGER-RNAS; PROTEIN-C; GENE; EXPRESSION; SEQUENCE; BINDING; CHAIN AB Targeted mutagenesis analysis has shown that the Cmyb proto-oncogene, which encodes a sequence-specific DNA binding protein, is required for normal murine fetal liver erythropoiesis and myelopoiesis. To identify novel genes involved in hematopoiesis, differential display analysis was conducted using total liver RNA isolated from 14.5-day postcoitus Cmyb wildtype, heterozygous, and homozygous mutant littermates. Using 4 oligo(dT) 3' primers and 5 arbitrary decamers as 5' primers, 22 differentially expressed genes have been identified. Eight putatively novel genes were identified from 12 cDNAs that were sequenced, One gene, initially designated DD7A5-7, is primarily expressed in cells of the myeloid lineage. The full-length DD7A5-7 cDNA is 3239 nucleotides, encoding a putative protein of 931 amino acids, The protein is a member of a family of hormone receptors containing 7 transmembrane segments. The receptor also contains 7 epidermal growth factor-like (Egf-like) motifs at the amino terminal of the predicted protein. The gene is alternatively spliced, resulting in the deletion of one or more copies of the Egf-like motif. DD7A5-7 maps to mouse Chromosome 17 and is the putative homologue of EMR1, a recently described Egf-like module containing mucin-like hormone receptor with 7 transmembrane segments in humans. Our results indicate that the Cmyb mutant fetuses represent a unique resource for identifying genes involved in hematopoiesis. (C) 1997 Academic Press. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. UNIV TENNESSEE,GRAD SCH BIOMED SCI,DIV BIOL,OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. OI Stubbs, Lisa/0000-0002-9556-1972 NR 42 TC 33 Z9 34 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 0888-7543 J9 GENOMICS JI Genomics PD MAY 1 PY 1997 VL 41 IS 3 BP 301 EP 308 DI 10.1006/geno.1997.4674 PG 8 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WX153 UT WOS:A1997WX15300001 PM 9169125 ER PT J AU Ianzano, L DApolito, M Centra, M Savino, M Levran, O Auerbach, AD CletonJansen, AM Doggett, NA Pronk, JC Tipping, AJ Gibson, RA Mathew, CG Whitmore, SA Apostolou, S Callen, DF Zelante, L Savoia, A AF Ianzano, L DApolito, M Centra, M Savino, M Levran, O Auerbach, AD CletonJansen, AM Doggett, NA Pronk, JC Tipping, AJ Gibson, RA Mathew, CG Whitmore, SA Apostolou, S Callen, DF Zelante, L Savoia, A TI The genomic organization of the Fanconi anemia group A (FAA) gene SO GENOMICS LA English DT Article ID DNA-BINDING; HUMAN CHROMOSOME-16; COMPLEMENTATION; TRANSCRIPTION; CLONING; REGION; FACC AB Fanconi anemia (FA) is a genetically heterogenous disease involving at least five genes on the basis of complementation analysis (FAA to FAE). The PAA gene has been recently isolated by two independent approaches, positional and functional cloning. In the present study we describe the genomic structure of the FAA gene. The gene contains 43 exons spanning approximately 80 kb as determined by the alignment of four cosmids and the fine localization of the first and the last exons in restriction fragments of these clones, Exons range from 34 to 188 bp. All but three of the splice sites were consistent with the ag-gt rule. We also describe three alternative splicing events in cDNA clones that result in the loss of exon 37, a 23-bp deletion at the 5' end of exon 41, and a GCAG insertion at the 3' portion also in exon 41. Sequence analysis of the 5' region upstream of the putative transcription start site showed no obvious TATA and CAAT boxes, but did show a GO-rich region, typical of housekeeping genes. Knowledge of the structure of the PAA gene will provide an invaluable resource for the discovery of mutations in the gene that accounts for about 60-66% of FA patients. (C) 1997 Academic Press. C1 OSPED CSS, IRCCS, SERV GENET MED, I-71013 SAN GIOVANNI ROTONDO, ITALY. ROCKEFELLER UNIV, HUMAN GENET & HEMATOL LAB, NEW YORK, NY 10021 USA. LEIDEN UNIV, DEPT PATHOL, NL-2300 RA LEIDEN, NETHERLANDS. LOS ALAMOS NATL LAB, CTR HUMAN GENOME STUDIES, LOS ALAMOS, NM 87545 USA. FREE UNIV AMSTERDAM, DEPT HUMAN GENET, NL-1081 HV AMSTERDAM, NETHERLANDS. UNITED MED & DENT SCH, GUYS HOSP, DIV MED & MOL GENET, LONDON SE1 9RT, ENGLAND. ADELAIDE WOMENS & CHILDRENS HOSP, DEPT CYTOGENET & MOL GENET, ADELAIDE, SA 5006, AUSTRALIA. RI Callen, David/G-1975-2012; d'Apolito, Maria/G-5793-2012; Mathew, Christopher/G-3434-2015; Savoia, Anna/B-6463-2014; OI Mathew, Christopher/0000-0003-4178-1838; Savoia, Anna/0000-0002-2407-2696; Callen, David/0000-0002-6189-9991; Auerbach, Arleen/0000-0002-6911-8379 FU Telethon [E.0364] NR 24 TC 33 Z9 34 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 MAY 1 PY 1997 VL 41 IS 3 BP 309 EP 314 DI 10.1006/geno.1997.4675 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WX153 UT WOS:A1997WX15300002 PM 9169126 ER PT J AU Allison, DP Kerper, PS Doktycz, MJ Thundat, T Modrich, P Larimer, FW Johnson, DK Hoyt, PR Mucenski, ML Warmack, RJ AF Allison, DP Kerper, PS Doktycz, MJ Thundat, T Modrich, P Larimer, FW Johnson, DK Hoyt, PR Mucenski, ML Warmack, RJ TI Mapping individual cosmid DNAs by direct AFM imaging SO GENOMICS LA English DT Article ID ATOMIC-FORCE MICROSCOPY; SCANNING-TUNNELING-MICROSCOPY; ECO-RI ENDONUCLEASE; RESTRICTION-ENDONUCLEASE; PLASMID DNA; MOLECULES; COMPLEXES; IMMOBILIZATION; RECOGNITION; SURFACES AB Individual cosmid clones have been restriction mapped by directly imaging, with the atomic force microscope (AFM), a mutant EcoRI endonuclease site-specifically bound to DNA, Images and data are presented that locate six restriction sites, predicted from gel electrophoresis, on a 35-kb cosmid isolated from mouse chromosome 7. Measured distances between endonuclease molecules bound to lambda DNA, when compared to known values, demonstrate the accuracy of AFM mapping to better than Icb. These results may be extended to identify other important site-specific protein-DNA interactions, such as transcription factor and mismatch repair enzyme binding, difficult to resolve by current techniques. (C) 1997 Academic Press. C1 OAK RIDGE NATL LAB,DIV BIOL,OAK RIDGE,TN 37831. DUKE UNIV,DEPT BIOCHEM,DURHAM,NC 27710. RP Allison, DP (reprint author), OAK RIDGE NATL LAB,HLTH SCI RES DIV,POB 2008,OAK RIDGE,TN 37831, USA. RI Doktycz, Mitchel/A-7499-2011 OI Doktycz, Mitchel/0000-0003-4856-8343 NR 31 TC 37 Z9 38 U1 1 U2 7 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 MAY 1 PY 1997 VL 41 IS 3 BP 379 EP 384 DI 10.1006/geno.1997.4686 PG 6 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WX153 UT WOS:A1997WX15300011 PM 9169135 ER PT J AU Spicer, AP Seldin, MF Olsen, AS Brown, N Wells, DE Doggett, NA Itano, N Kimata, K Inazawa, J McDonald, JA AF Spicer, AP Seldin, MF Olsen, AS Brown, N Wells, DE Doggett, NA Itano, N Kimata, K Inazawa, J McDonald, JA TI Chromosomal localization of the human and mouse hyaluronan synthase genes SO GENOMICS LA English DT Article ID IN-SITU HYBRIDIZATION; MAPPING PANEL; LINKAGE MAP; HUMAN-CHROMOSOME-19; IDENTIFICATION; MUTATION; CLONING AB We have recently identified a new vertebrate gene family encoding putative hyaluronan (HA) synthases. Three highly conserved related genes have been identified, designated HAS1, HAS2, and HAS3 in humans and Has1, Has2, and Has3 in the mouse, All three genes encode predicted plasma membrane proteins with multiple transmembrane domains and approximately 25% amino acid sequence identity to the Streptococcus pyogenes HA synthase, HasA. Furthermore, expression of any one AAS gene in transfected mammalian cells leads to high levels of HA biosynthesis. We now report the chromosomal localization of the three HAS genes in human and in mouse. The genes localized to three different positions within both the human and the mouse genomes. HAS1 was localized to the human chromosome 19q13.3-q13.4 boundary and Has1 to mouse Chr 17. HAS2 was localized to human chromosome 8q24.12 and Has2 to mouse Chr 15. HAS3 was localized to human chromosome 16q22.1 and Has3 to mouse Chr 8, The map position for HAS1 reinforces the recently reported relationship between a small region of human chromosome 19q and proximal mouse chromosome 17, HAS2 mapped outside the predicted critical region delineated for the Langer-Giedion syndrome and can thus be excluded as a candidate gene for this genetic syndrome. (C) 1997 Academic Press. C1 UNIV CALIF DAVIS,DEPT BIOL CHEM,DAVIS,CA 95616. UNIV CALIF DAVIS,DEPT MED,DAVIS,CA 95616. LAWRENCE LIVERMORE NATL LAB,CTR HUMAN GENOME,LIVERMORE,CA 94550. UNIV HOUSTON,DEPT BIOL,HOUSTON,TX 77204. UNIV HOUSTON,INST MOL BIOL,HOUSTON,TX 77204. LOS ALAMOS NATL LAB,CTR HUMAN GENOME STUDIES,LOS ALAMOS,NM 87545. LOS ALAMOS NATL LAB,DIV LIFE SCI,LOS ALAMOS,NM 87545. AICHI MED UNIV,INST MOL SCI MED,NAGAKUTE,AICHI 48011,JAPAN. KYOTO PREFECTURAL UNIV MED,DEPT HYG,KAMIGYO KU,KYOTO 602,JAPAN. RP Spicer, AP (reprint author), MAYO CLIN SCOTTSDALE,DEPT BIOCHEM & MOL BIOL,13400 E SHEA BLVD,SCOTTSDALE,AZ 85259, USA. FU NHGRI NIH HHS [HG00734]; NHLBI NIH HHS [I F32 HL09311-01]; NICHD NIH HHS [HD27981] NR 33 TC 67 Z9 68 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 MAY 1 PY 1997 VL 41 IS 3 BP 493 EP 497 DI 10.1006/geno.1997.4696 PG 5 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA WX153 UT WOS:A1997WX15300030 PM 9169154 ER PT J AU Newman, BD Campbell, AR Norman, DI Ringelberg, DB AF Newman, BD Campbell, AR Norman, DI Ringelberg, DB TI A model for microbially induced precipitation of vadose-zone calcites in fractures at Los Alamos, New Mexico, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ISOTOPIC COMPOSITION; FATTY-ACIDS; CARBONATE; SEDIMENTS; BACTERIA; SOILS; CHROMATOGRAPHY; ENVIRONMENT; ECOLOGY; OXALATE AB Fractures are unique environments that can concentrate the flow of water, nutrients, and contaminants. As such, fractures play an important role in controlling the flux of various substances into and through the vadose zone. Calcite fracture fillings are present in the near surface in the Bandelier Tuff Formation at Los Alamos, New Mexico, and provide a record of the geochemical and hydrologic processes that have occurred in fractures. The objective of this study was to examine calcite fracture fills in order to improve understanding of processes within fractures, and in particular those that lead to precipitation of calcite. Samples of calcite fillings were collected from vertical and horizontal fractures exposed in a shallow waste-burial pit. Scanning electron microscopy show morphologies which suggest that plants, fungi, and bacteria were important in the precipitation process. Quadrupole mass spectrometric analyses of fluid inclusion gases show predominantly methane (17-99%) and little to no oxygen (0-8%), suggesting the development of anaerobic conditions in the fractures. Ester-linked phospholipid biomarkers are evidence for a diverse microbial community in the fractures, and the presence of di-ether lipids indicate that the methane was generated by anaerobic bacteria. The calcite fillings apparently resulted from multiple biological and chemical processes in which plant roots in the fractures were converted to calcite. Roots grew into the fractures, eventually died, and were decomposed by bacteria and fungi. Anaerobic gases were generated from encapsulated organic material within the calcite via microbial decomposition, or were generated by microbes simultaneously with calcite precipitation. It is likely that the biological controls on calcite formation that occurred in the Los Alamos fractures also occurs in soils, and may explain the occurrence of other types of pedogenic calcites. (C) 1997 Elsevier Science Ltd. C1 NEW MEXICO INST MIN & TECHNOL,DEPT EARTH & ENVIRONM SCI,SOCORRO,NM 87801. UNIV TENNESSEE,CTR ENVIRONM BIOTECHNOL,KNOXVILLE,TN 37932. RP Newman, BD (reprint author), LOS ALAMOS NATL LAB,ENVIRONM SCI GRP,LOS ALAMOS,NM 87545, USA. NR 41 TC 8 Z9 8 U1 0 U2 5 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 MAY PY 1997 VL 61 IS 9 BP 1783 EP 1792 DI 10.1016/S0016-7037(97)00025-2 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XA887 UT WOS:A1997XA88700001 ER PT J AU Denniston, RF Shearer, CK Layne, GD Vaniman, DT AF Denniston, RF Shearer, CK Layne, GD Vaniman, DT TI SIMS analyses of minor and trace element distributions in fracture calcite from Yuccca Mountain, Nevada, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID RARE-EARTH ELEMENTS; ION MICROPROBE; FERROMANGANESE NODULES; SILICIC TUFF; CATHODOLUMINESCENCE; CARBONATES; MINERALS; MANGANESE; GEOCHEMISTRY; ROCKS AB Fracture-lining calcite samples from Yucca Mountain, Nevada, obtained as part of the extensive vertical sampling in studies of this site as a potential high-level waste repository, ha ie been characterized according to microbeam-scale (25-30 mu m) trace and minor element chemistry, and cathodoluminescent zonation patterns. As bulk chemical analyses are limited in spatial resolution and are subject to contamination by intergrown phases, a technique for analysis by secondary ion mass spectrometry (SIMS) of minor (Mn, Fe, Sr) and trace (REE) elements in calcite was developed and applied to eighteen calcite samples from four boreholes and one trench. SIMS analyses of REE in calcite and dolomite have been shown to be quantitative to abundances <1 x chondrite. Although the low secondary ion yields associated with carbonates forced higher counting times than is necessary in most silicates, Mn, Fe, Sr, and REE analyses were obtained with sub-ppm detection limits and 2-15% analytical precision. Bulk chemical signatures noted by Vaniman (1994) allowed correlation of minor and trace element signatures in Yucca Mountain calcite with location of calcite precipitation (saturated vs. unsaturated zone). For example, upper unsaturated zone calcite exhibits pronounced negative Ce and Eu anomalies not observed in calcite collected below in the deep unsaturated zone. These chemical distinctions served as fingerprints which were applied to growth zones in order ro examine temporal changes in calcite crystallization histories; analyses of such fine-scale zonal variations are unattainable using bulk analytical techniques. In addition, LREE (particularly Ce) scavenging of calcite-precipitating solutions by manganese oxide phases is discussed as the mechanism for Ce-depletion in unsaturated zone calcite. (C) 1997 Elsevier Science Ltd. C1 UNIV NEW MEXICO,DEPT EARTH & PLANETARY SCI,INST METEORIT,ALBUQUERQUE,NM 87131. LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,LOS ALAMOS,NM 87545. NR 54 TC 25 Z9 27 U1 0 U2 6 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 MAY PY 1997 VL 61 IS 9 BP 1803 EP 1818 DI 10.1016/S0016-7037(97)00049-5 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XA887 UT WOS:A1997XA88700003 ER PT J AU Farges, F Brown, GE AF Farges, F Brown, GE TI Coordination chemistry of titanium(IV) in silicate glasses and melts .4. XANES studies of synthetic and natural volcanic glasses and tektites at ambient temperature and pressure SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID X-RAY-ABSORPTION; MULTIPLE-SCATTERING CALCULATIONS; ISLAND-ARC BASALTS; TI; CLINOPYROXENE; AMPHIBOLES; RICHTERITE; BEHAVIOR; SPECTRA; MAGMAS AB The coordination environment of Ti(IV) in seven natural and synthetic glasses of basaltic, trachytic, rhyolitic composition as well as four tektites has been studied using high-resolution Ti K-edge x-ray absorption near edge structure (XANES) spectroscopy at ambient temperature and pressure. Pre-edge features of Ti K-edge XANES spectra for these glasses suggest that Ti-[15] is the dominant Ti coordination in all volcanic glasses. However, in the less polymerized glasses studied (basaltic and trachytic), Ti-[6] is also important (30-50% of the total Ti) but Ti-[4] was not detected. In contrast, Ti-[4] is important in the most polymerized glasses (rhyolites and tektites) (from 30 to 60% of the total Ti depending on NBO/T) with Ti-[6] below the detection level (approximate to 10 at%). The local structure around Ti in the natural volcanic glasses is similar to that observed in compositionally similar synthetic silicate glasses and also in Ti bearing silicate glass and melts with simpler compositions. The presence of F, Cl, and H2O does not appear to affect the coordination of Ti, based on Ti Kedge XANES measurements of natural glasses bearing these volatile components. In contrast, the presence of nonbridging oxygens (produced by network modifiers) favors Ti-[5] in these glass/melts. In parallel, Ti-[4] is important when nonbridging oxygens are at small concentrations (NBO/T < 0.1). Ti-[6] is detected (i.e., when present >10% of the total Ti) when alkaline-earths are dominant over alkalis, in agreement with bond-valence *predictions for Ti-bearing silicate glass/melts below TiO2 saturation. The abundance of Ti-[5] in these silicate glasses (and presumably their melts) is in sharp contrast with the rarity of this Ti coordination state in common rock-forming minerals. Titanium cannot readily enter the structure of most rock-forming minerals, because it is present dominantly as titanyl-bearing (Ti-[5]=0) units in most natural magmas. In contrast, Ti-[6] and Ti-[4] (present, respectively, in basic and acidic magmas) are better able to enter inosilicates, but these coordination states represent only a fraction of the Ti in basalts, explaining the usually moderate level of incompatibility of Ti during magmatic differentiation. Finally, Ti-[5] transforms to Ti-[6] during crystallization of Ti-rich minerals (ilmenite, rutile,pyrochlore). Copyright (C) 1997 Elsevier Science Ltd. C1 URA CNRS 734,F-93166 NOISY LE GRAND,FRANCE. LURE,F-93166 NOISY LE GRAND,FRANCE. STANFORD UNIV,STANFORD SYNCHROTRON RADIAT LAB,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. RP Farges, F (reprint author), UNIV MARNE LA VALLEE,LAB PHYS & MECAN GEOMAT,F-93166 NOISY LE GRAND,FRANCE. NR 39 TC 44 Z9 44 U1 2 U2 21 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 MAY PY 1997 VL 61 IS 9 BP 1863 EP 1870 DI 10.1016/S0016-7037(97)00050-1 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XA887 UT WOS:A1997XA88700007 ER PT J AU Kelley, MC Baker, SD Holzworth, RH Argo, P Cummer, SA AF Kelley, MC Baker, SD Holzworth, RH Argo, P Cummer, SA TI LF and MF observations of the lightning electromagnetic pulse at ionospheric altitudes SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PROPAGATION AB For the first time the full ionospheric signature of the lightning electromagnetic pulse (EMP) was measured up to a frequency of 2 MHz. At altitudes below 225 km, the upward-going whistler wave is found to have a nose-whistler wave shape with the fastest propagating frequency (nose frequency) near 80 kHz. The bulk of the EMP energy is at the nose frequency, and there is a sharp upper limit near 175 kHz where the group delay is very long. We believe the group delay is due to a propagation resonance for the whistler mode (slightly non-longitudinal propagation) associated with the low plasma frequencies in the F-layer valley. MF emissions were seen below the F peak, but not above. These results verify earlier speculation that the leading intense edge of the lightning EMP was carried by 50-125 kHz waves. In addition, we present tantalizing evidence for detection of a pulse pair prior to the stroke that is similar to transionospheric pulse pairs (TIPPs) detected in satellite data. C1 UNIV WASHINGTON,GEOPHYS PROGRAM,SEATTLE,WA 98195. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. STANFORD UNIV,STAR LAB,STANFORD,CA 94305. RP Kelley, MC (reprint author), CORNELL UNIV,SCH ELECT ENGN,ITHACA,NY 14853, USA. RI Cummer, Steven/A-6118-2008 OI Cummer, Steven/0000-0002-0002-0613 NR 9 TC 14 Z9 14 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 MAY 1 PY 1997 VL 24 IS 9 BP 1111 EP 1114 DI 10.1029/97GL00991 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WX269 UT WOS:A1997WX26900028 ER PT J AU Maksimovic, M Pierrard, V Riley, P AF Maksimovic, M Pierrard, V Riley, P TI Ulysses electron distributions fitted with Kappa functions SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SOLAR-WIND; ION AB We fit Kappa functions to 16,000 velocity distribution functions measured in the solar wind by the electron plasma instrument on board Ulysses. Statistically, the electron distributions are observed to have important high velocity tails in the fast solar wind but are closer to a Maxwellian in the slow wind. We also discuss how this result could support a recent kinetic model of the solar wind proposed by Maksimovic, Pierrard and Lemaire [1997]. C1 INST AERON SPATIALE BELGIQUE,B-1180 BRUSSELS,BELGIUM. LOS ALAMOS NATL LAB,NONPROLIFERAT & INT SECUR DIV,GRP NIS 1,LOS ALAMOS,NM 87545. RP Maksimovic, M (reprint author), OBSERV PARIS,DEPT RECH SPATIALE,CNRS,URA 264,F-92195 MEUDON,FRANCE. OI Pierrard, Viviane/0000-0001-5014-7682 NR 21 TC 214 Z9 216 U1 0 U2 4 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 MAY 1 PY 1997 VL 24 IS 9 BP 1151 EP 1154 DI 10.1029/97GL00992 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WX269 UT WOS:A1997WX26900038 ER PT J AU Desai, MI Marsden, RG Sanderson, TR Balogh, A Forsyth, RJ Gosling, JT AF Desai, MI Marsden, RG Sanderson, TR Balogh, A Forsyth, RJ Gosling, JT TI Particle acceleration at corotating reverse shocks in the southern hemisphere: Ulysses results SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INTERACTION REGIONS; SOLAR; ENHANCEMENTS; STREAM AB We have correlated the similar to 1 MeV proton intensity (J) measured at corotating reverse shocks detected by Ulysses in the southern hemisphere with two parameters that characterise the strength of the shock. Between 6 degrees-29 degrees S J is essentially independent of the shock strength, whereas between 29 degrees-41 degrees S J is well correlated with the same. The poor correlation from 6 degrees S to 29 degrees S is attributed to variations in the background intensity caused by changes in solar activity. Our results also show that J is independent of the shock normal angle at all latitudes. We compensate for the effects of a fluctuating background by assuming that reverse shocks associated with two adjacent compression regions observed during a similar to 26 day period accelerate particles out of the same seed population. The relation between the ratio of the proton intensities and the ratios of the shock parameters for such reverse shock-pairs indicates that the shock acceleration efficiency increases with the shock strength but is independent of the normal angle. C1 UNIV LONDON IMPERIAL COLL SCI TECHNOL & MED,BLACKETT LAB,LONDON SW7 2BZ,ENGLAND. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Desai, MI (reprint author), EUROPEAN SPACE AGCY,ESTEC,DEPT SPACE SCI,NL-2200 AZ NOORDWIJK,NETHERLANDS. NR 17 TC 9 Z9 9 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 MAY 1 PY 1997 VL 24 IS 9 BP 1155 EP 1158 DI 10.1029/97GL00862 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WX269 UT WOS:A1997WX26900039 ER PT J AU Milligan, PA Rector, JW Bainer, RW AF Milligan, PA Rector, JW Bainer, RW TI Hydrophone VSP imaging at a shallow site SO GEOPHYSICS LA English DT Article AB We evaluated the capabilities of vertical seismic profiling (VSP) for imaging the complex heterogeneous unconsolidated sedimentary structures at a shallow site. We deployed a 24-level hydrophone array with 0.5-m level spacing down a preexisting poly vinyl chloride (PVC) cased well. Data acquisition time was quick. Only 15 multioffset shot points using a hammer-on-plate source were needed to acquire reflection data between the water table at 3 m and the bedrock at 35 m to produce a depth section image. This image extended 9 m from the receiver will, yielding resolutions between fresh-water-bearing sands and impermeable muds and clays of better than 1 m. Depth accuracy of the image was confirmed by good correlation with cone penetrometer logs. We used conventional wavefield separation and VSP-CDP mapping techniques to image the data. Tube waves, created by seismic arrivals at cross-sectional area changes in the borehole fluid column, were the primary source of coherent noise in the data. The tube-wave arrival structure was complicated by the hydrophone array, which generated and scattered tube waves at each hydrophone pod. To combat the tube wave interference, we inserted closed-cell-foam baffles between elements. The baffles attenuated and slowed the tube waves, and reduced generation and scattering. A comparison between unbaffled and baffled VSP data showed that baffling increased the maximum useful frequency from 300 Hz to over 900 Hz. By contrast, surface shot data recorded at the same site, using buried 40-Hz vertical geophones, exhibited useful frequencies of less than 250 Hz. In addition, coherent noise in surface shot records caused by air waves and first arrivals made it very difficult to identify shallow reflections above 25 m. Reflections from depths as shallow as 10 m were easy to identify in the baffled VSP data. C1 UNIV CALIF BERKELEY,DEPT MAT SCI & MINERAL ENGN,BERKELEY,CA 94270. LAWRENCE LIVERMORE NATL LAB,ENVIRONM RESTORAT DIV,LIVERMORE,CA 94551. RP Milligan, PA (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ENGN GEOSCI DEPT,BLDG 90,ROOM 2002,BERKELEY,CA 94270, USA. NR 20 TC 11 Z9 11 U1 0 U2 0 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD MAY-JUN PY 1997 VL 62 IS 3 BP 842 EP 852 DI 10.1190/1.1444193 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA XB685 UT WOS:A1997XB68500014 ER PT J AU Nyquist, JE AF Nyquist, JE TI Unmanned aerial vehicles that even geoscience departments can afford SO GEOTIMES LA English DT Article RP Nyquist, JE (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. RI Nyquist, Jonathan/B-2240-2010 NR 4 TC 4 Z9 4 U1 2 U2 3 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD MAY PY 1997 VL 42 IS 5 BP 20 EP 23 PG 4 WC Geosciences, Multidisciplinary SC Geology GA WW881 UT WOS:A1997WW88100021 ER PT J AU Bishop, CW Porro, I AF Bishop, CW Porro, I TI Comparison of neutron moisture gauges and a neutron tool for use in monitoring wells SO GROUND WATER LA English DT Article ID PROBE AB Research at the Idaho National Engineering Laboratory investigated the movement of water through a thick fractured basalt vadose zone. Measurements taken in 20-cm diameter boreholes completed with 10.2-cm diameter PVC casing and in specially constructed test containers filled with basalt showed that 50-m Ci neutron moisture gauges could distinguish differences in moisture levels in the basalt formation beyond the well's annular space. Measurements made at depths up to 55 m in similarly constructed monitoring wells in the field showed that moisture gauge readings lead to the same interpretation of moisture movement as readings made with a 3-Ci neutron tool. RP Bishop, CW (reprint author), LOCKHEED MARTIN IDAHO TECHNOL,IDAHO NATL ENGN LAB,POB 1625,IDAHO FALLS,ID 83415, USA. NR 8 TC 1 Z9 1 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAY-JUN PY 1997 VL 35 IS 3 BP 394 EP 399 DI 10.1111/j.1745-6584.1997.tb00098.x PG 6 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA WX770 UT WOS:A1997WX77000004 ER PT J AU MasPla, J Yeh, TCJ Williams, TM McCarthy, JF AF MasPla, J Yeh, TCJ Williams, TM McCarthy, JF TI Analyses of slug tests and hydraulic conductivity variations in the near field of a two-well tracer experiment site SO GROUND WATER LA English DT Article ID PARTIALLY PENETRATING WELLS; NATURAL GRADIENT EXPERIMENT; SANDY AQUIFER; HETEROGENEOUS AQUIFER; SOLUTE TRANSPORT; DISPERSION; SIMULATION; BOUWER AB Three-hundred eight slug tests were conducted in a 5 x 5 m area in a coastal, sandy aquifer at the Georgetown site in South Carolina to characterize three-dimensional aquifer heterogeneity. Methods developed by Hvorslev, Bouwer and Rice, and Cooper et al. were employed to estimate hydraulic conductivity values from the slug test data. These three methods produced similar spatial distributions of the hydraulic conductivity but quite different values. Overall, the method of Cooper et al. produces higher conductivity values in high permeability zones but lower values in low permeability areas than the Hvorslev method. Variances of the natural log of conductivity values derived from Hvorslev's and Bouwer and Rice's methods agree with those in the other aquifers under similar depositional environments. However, the variance calculated for the data based on the method of Cooper et al. appears unreasonably large. Despite these differences, histograms of the three sets of conductivity values exhibit bimodal distributions, reflecting stratification of the aquifer. Geostatistical analyses show that correlation lengths and statistical anisotropy of the hydraulic conductivity spatial structure varies with depth. C1 UNIV ARIZONA,DEPT HYDROL & WATER RESOURCES,TUCSON,AZ 85721. CLEMSON UNIV,COLL FOREST & RECREAT RESOURCES,BELLE W BARUCH FOREST SCI INST,GEORGETOWN,SC 29442. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RP MasPla, J (reprint author), UNIV AUTONOMA BARCELONA,DEPT GEOL,UNITAT GEODINAM EXTERNA HIDROGEOL 1,BELLATERRA 08193,SPAIN. RI Mas-Pla, Josep/B-9582-2009 OI Mas-Pla, Josep/0000-0002-8491-9895 NR 29 TC 9 Z9 9 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAY-JUN PY 1997 VL 35 IS 3 BP 492 EP 501 DI 10.1111/j.1745-6584.1997.tb00110.x PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA WX770 UT WOS:A1997WX77000016 ER PT J AU Stabin, MG Stubbs, JB Russell, JR AF Stabin, MG Stubbs, JB Russell, JR TI Review of the fetal radiation doses received from Fe-59 kinetic studies at Vanderbilt University in the 1940's SO HEALTH PHYSICS LA English DT Article DE radiation dose; exposure; prenatal; dose assessment; Iron AB Fetal radiation dose estimates were calculated for women who received oral administrations of Fe-59 at Vanderbilt University in the 1940's. A similar dosimetry analysis was performed by Dyer and Brill in 1972; the availability of recently developed physical models of the pregnant female at different stages of gestation and of a new kinetic model for iron metabolism afforded an opportunity to re-evaluate these doses. Radiation dose estimates for the fetus (and fetal liver in three cases) were calculated for a number of oral and intravenous studies using these new models and the available data about the original experiments, The total fetal doses do not appear to have exceeded a few hundred microgray (a few tens of millirad) for the majority of the study subjects. Considerable uncertainty exists, however, in the amount of activity administered to these subjects. C1 OAK RIDGE INST SCI EDUC, OAK RIDGE, TN 37831 USA. RADIAT DOSIMETRY SYST INC, KNOXVILLE, TN 37932 USA. JACOBS ENGN GRP, WASHINGTON, DC 20024 USA. NR 16 TC 5 Z9 5 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAY PY 1997 VL 72 IS 5 BP 701 EP 707 DI 10.1097/00004032-199705000-00004 PG 7 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 WT523 UT WOS:A1997WT52300005 PM 9106710 ER PT J AU Elless, MP Armstrong, AQ Lee, SY AF Elless, MP Armstrong, AQ Lee, SY TI Characterization and solubility measurements of uranium-contaminated soils to support risk assessment SO HEALTH PHYSICS LA English DT Article DE uranium; risk analysis; health effects; soil AB Remediation of uranium-contaminated soils is considered a high priority by the U.S. Department of Energy because these soils, if left untreated, represent a hazard to the environment and human health. Because the risk to human health is a function of the solubility of uranium in the soils, the objectives of this work are to measure the uranium solubility of two contaminated soils, before and after remedial treatment, and determine the health risk associated with these soils. Two carbonate-rich. uranium-contaminated soils from the U.S. Department of Energy Fernald Environmental Management Project facility near Cincinnati, Ohio, as well as two nearby background soils were characterized and their uranium solubility measured in a 75-d solubility experiment using acid rain, groundwater, lung serum, and stomach acid simulants. Results show that the soluble uranium levels of each soil by each simulant are greatly influenced by their contamination source term. Risk calculations and biokinetic modeling based on the solubility data show that the risks from the soil ingestion and groundwater ingestion pathways are the predominant contributors to the total carcinogenic risk, whereas the risk from the soil inhalation pathway is the smallest contributor to this risk. However, kidney toxicity was the greater health concern of the Fernald Environmental Management Project soils, primarily from undiluted ingestion of the groundwater solution following contact with the contaminated soils. Sensitivity analyses indicate that uranium solubility is a key parameter in defining kidney toxicity; therefore, without proper consideration of the solubility of radionuclides/metals in untreated and treated soils, important factors mag be overlooked which may result in soil cleanup goals or limits which are not protective of human health and the environment, We recommend that characterization and measurement of target radionuclides/metals solubilities should also be required by the regulatory community to support the establishment of scientifically-sound, site-specific, soil cleanup goals or limits. C1 PHYTOTECH INC, MONMOUTH JCT, NJ 08852 USA. OAK RIDGE NATL LAB, OAK RIDGE, TN 37830 USA. NR 31 TC 13 Z9 13 U1 0 U2 12 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAY PY 1997 VL 72 IS 5 BP 716 EP 726 DI 10.1097/00004032-199705000-00007 PG 11 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 WT523 UT WOS:A1997WT52300008 PM 9106713 ER PT J AU Whicker, JJ Rodgers, JC Fairchild, CI Scripsick, RC Lopez, RC AF Whicker, JJ Rodgers, JC Fairchild, CI Scripsick, RC Lopez, RC TI Evaluation of continuous air monitor placement in a plutonium facility SO HEALTH PHYSICS LA English DT Article DE air sampling; radiation protection; plutonium; uranium AB Department of Energy appraisers found continuous air monitors at Department of Energy plutonium facilities alarmed less than 30% of the time when integrated room plutonium air concentrations exceeded 500 DAC-hours. Without other interventions, this alarm percentage suggests the possibility that workers could be exposed to high airborne concentrations without continuous air monitor alarms. Past research has shown that placement of continuous air monitors is a critical component in rapid and reliable detection of airborne releases. At Los Alamos National Laboratory and many other Department of Energy plutonium facilities, continuous air monitors have been primarily placed at ventilation exhaust points. The purpose of this study was to evaluate and compare the effectiveness of exhaust register placement of workplace continuous air monitors with other sampling locations. Polydisperse oil aerosols were released from multiple locations in two plutonium laboratories at Los Alamos National Laboratory, An array of laser particle counters positioned in the rooms measured time-resolved aerosol dispersion. Results showed alternative placement of air samplers generally resulted in aerosol detection that was faster, often more sensitive, and equally reliable compared with samplers at exhaust registers. C1 LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. NR 19 TC 12 Z9 12 U1 1 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 MAY PY 1997 VL 72 IS 5 BP 734 EP 743 DI 10.1097/00004032-199705000-00009 PG 10 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 WT523 UT WOS:A1997WT52300010 PM 9106715 ER PT J AU Sims, CS AF Sims, CS TI NRC regulation of DOE nuclear safety: An observation and some questions concerning radiation doses SO HEALTH PHYSICS LA English DT Letter C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0017-9078 EI 1538-5159 J9 HEALTH PHYS JI Health Phys. PD MAY PY 1997 VL 72 IS 5 BP 798 EP 798 PG 1 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 WT523 UT WOS:A1997WT52300020 PM 9106725 ER PT J AU Suter, GW Sample, BE AF Suter, GW Sample, BE TI Addendum to ''annotated reference compilation, 1995 update: Conducting ecological risk assessments at hazardous waste sites'' SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Letter RP Suter, GW (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD MAY PY 1997 VL 3 IS 2 BP 125 EP 126 PG 2 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA XN616 UT WOS:A1997XN61600002 ER PT J AU Bogen, KT AF Bogen, KT TI Do US county data disprove linear no-threshold predictions of lung cancer risk for residential radon? A preliminary assessment of biological plausibility SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Review ID ALPHA-PARTICLE IRRADIATION; STATES URANIUM MINERS; CELL-PROLIFERATION; UNITED-STATES; INDOOR RADON; EPITHELIAL-CELLS; ONCOGENIC TRANSFORMATION; BRONCHIAL EPITHELIUM; RESPIRATORY-TRACT; DECAY PRODUCTS AB Lung-cancer mortality (LCM) is elevated in underground miners who chronically inhaled the mutagenic, cytotoxic alpha-decay products of radon gas. Epidemiologic studies of LCM rates vs. residential-radon concentration levels are generally considered inconclusive. However, Cohen (Health Physics 68, 157-174, 1995) has hypothesized that data on LCM vs. residential radon concentrations at the U.S. county level are clearly inconsistent with a linear no-threshold (LN) dose-response model, and rather are consistent with threshold or hormesis model. Cohen's hypothesis has been criticized as ''ecological fallacy,'' particularly because LN (but not threshold or hormesis) models are generally considered biologically plausible for agents like a radiation that damage DNA in linear proportion to dose. To assess the biological plausibility of Cohen's hypothesis, a preliminary study was made of whether a biologically realistic, cytodynamic 2-stage (CD2) cancer model can provide a good, joint fit to Cohen's set of U.S. county data as well as to underground-miner data. The CD2 model used adapts a widely applied, mechanistic, 2-stage stochastic model of carcinogenesis to realistically account for interrelated cell killing and mutation (both assumed to have a EN dose-response), cell turnover, and incomplete exposure of stem cells. A CD2 fit was obtained to combined summary data on ECM vs. radon-exposure in white males in 1,601 U.S. counties (from Cohen) and in white male Colorado Plateau (CP) uranium miners (from the National Research Council's ''BEIR IV'' report). The CD2 fit is shown to: (if be consistent with the combined data; (ii) have parameter values all consistent with biological data; and (iii) predict inverse dose-rate-effects data for CP and other radon-exposed miners, despite the fact that optimization had not involved any of these dose-rate data. The latter data were not predicted by a simplified CD2 model in which all stem cells were presumed to be exposed. It is concluded that this study provides preliminary evidence that Cohen's hypothesis is biologically plausible. RP Bogen, KT (reprint author), LAWRENCE LIVERMORE NATL LAB,HLTH & ECOL ASSESSMENT DIV L396,LIVERMORE,CA 94550, USA. NR 168 TC 16 Z9 16 U1 1 U2 2 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD MAY PY 1997 VL 3 IS 2 BP 157 EP 186 PG 30 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA XN616 UT WOS:A1997XN61600007 ER PT J AU Wilcox, BP Breshears, DD AF Wilcox, BP Breshears, DD TI Interflow in semiarid environments: An overlooked process in risk assessment SO HUMAN AND ECOLOGICAL RISK ASSESSMENT LA English DT Article DE runoff; contaminant transport; interflow; New Mexico hydrology; risk assessment; RESRAD; tritium; uranium; plutonium; landfill ID REMEDIATION; FLOW AB Risk assessment, both human and ecological, embodies fundamental assumptions about hydrological processes, especially how they affect the movement of contaminants in the environment. The lateral movement of water through the soil, or interflow, is frequently a component of risk assessments for humid environments, but not of those for semiarid environments. Our research has shown that, contrary to what was previously thought, interflow can be important in semiarid landscapes and is, therefore, an essential consideration for risk assessment in these regions. To illustrate and assess the effect of interflow on estimates of risk, we (1) developed a simple conceptual model to describe the role that interflow may have in the redistribution of surface and near-surface contamination, and (2) used RESRAD, an exposure model for assessing radionuclide doses to humans, to evaluate the effectiveness of landfill covers in mitigating doses of three contaminants (H-3, U-238, and Pu-239/240) at a site in northern New Mexico at which interflow is known to be occurring. Only those calculations of the model that took interflow into account yielded the result that the radionuclides would contaminate groundwater - underscoring the potential importance of interflow as a mechanism for the transport of contaminants. We conclude that failure to take interflow into account can render risk assessments inaccurate and remediation ineffective. Further, our work demonstrates that a general understanding of hydrological processes is essential for accurate risk assessment, ecological as well as human. C1 LOS ALAMOS NATL LAB,ENVIRONM SCI GRP,LOS ALAMOS,NM. INTERAMER INST GLOBAL CHANGE RES,BR-12227010 S JOSE CAMPOS,SP,BRAZIL. RI Breshears, David/B-9318-2009 OI Breshears, David/0000-0001-6601-0058 NR 41 TC 6 Z9 6 U1 0 U2 5 PU CRC PRESS INC PI BOCA RATON PA 2000 CORPORATE BLVD NW, JOURNALS CUSTOMER SERVICE, BOCA RATON, FL 33431 SN 1080-7039 J9 HUM ECOL RISK ASSESS JI Hum. Ecol. Risk Assess. PD MAY PY 1997 VL 3 IS 2 BP 187 EP 203 PG 17 WC Biodiversity Conservation; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA XN616 UT WOS:A1997XN61600008 ER PT J AU McNeil, SM Novelletto, A Srinidhi, J Barnes, G Kornbluth, I Altherr, MR Wasmuth, JJ Gusella, JF MacDonald, ME Myers, RH AF McNeil, SM Novelletto, A Srinidhi, J Barnes, G Kornbluth, I Altherr, MR Wasmuth, JJ Gusella, JF MacDonald, ME Myers, RH TI Reduced penetrance of the Huntington's disease mutation SO HUMAN MOLECULAR GENETICS LA English DT Article ID TRINUCLEOTIDE REPEAT EXPANSION; POLYMERASE CHAIN-REACTION; (CAG)(N) REPEAT; INTERMEDIATE ALLELES; INSTABILITY; FAMILIES; LENGTH; ONSET; AGE; POLYMORPHISM AB Controversy persists concerning the significance of Huntington disease (HD) alleles in the 36-39 repeat range, Although some clinically affected persons have been documented with repeats in this range, elderly unaffected individuals have also been reported, We examined 10 paternal transmissions of HD alleles of 37-39 repeats in collateral branches of families with de novo HD. All 10 descendants, including many who are elderly, are without symptoms of HD, Forty percent of the transmissions were unstable, although none varied by more than one repeat. The observation that individuals with alleles of 37-39 repeats may survive unaffected beyond common life expectancy supports the presence of reduced penetrance for HD among some persons with repeat sizes which overlap the clinical range, Non-penetrance may be increased in the collateral branches of de novo mutation families when compared to penetrance estimates from patient series, There was no CAA-->CAG mutation for the penultimate glutamine in either a de novo expanded 42 repeat allele or the corresponding non-penetrant 38 repeat allele in a family with fresh mutation to HD. C1 BOSTON UNIV,SCH MED,DEPT NEUROL,BOSTON,MA 02118. UNIV ROMA TOR VERGATA,DEPT BIOL,I-00173 ROME,ITALY. HARVARD UNIV,MASSACHUSETTS GEN HOSP,SCH MED,MOL NEUROGENET UNIT,BOSTON,MA 02114. LOS ALAMOS NATL LAB,HLTH RES LAB,LOS ALAMOS,NM 87545. UNIV CALIF IRVINE,DEPT BIOL CHEM,IRVINE,CA 92717. OI Novelletto, Andrea/0000-0002-1146-7680 FU NINDS NIH HHS [NS16367]; Telethon [E.0087] NR 31 TC 82 Z9 83 U1 1 U2 7 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 MAY PY 1997 VL 6 IS 5 BP 775 EP 779 DI 10.1093/hmg/6.5.775 PG 5 WC Biochemistry & Molecular Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Genetics & Heredity GA WX608 UT WOS:A1997WX60800016 PM 9158152 ER PT J AU Camp, LJ Sirbu, M AF Camp, LJ Sirbu, M TI Critical issues in Internet commerce SO IEEE COMMUNICATIONS MAGAZINE LA English DT Article AB In this article the authors identify reliability, privacy, and security as critical issues in electronic commerce. In other work, designers of information systems have identified other issues as critical, such as the ability to provide offline verification. It is widely agreed that an electronic currency system must provide divisibility, scalability in number of users, conservation of money or tamper resistance, exchangeability or interoperability, and availability [1-6]. However, by returning to the fundamental definition of money and the essential nature of electronic information systems, the authors argue that privacy, reliability, and security are also critical issues. It is argued that these issues are particularly important in Internet commerce. The authors conclude by noting how some proposed Internet commerce systems provide, or fail to provide, security, reliability, and privacy. C1 CARNEGIE MELLON UNIV,GRAD SCH IND ADM,PITTSBURGH,PA 15213. RP Camp, LJ (reprint author), SANDIA NATL LABS,TECH STAFF,LIVERMORE,CA 94550, USA. OI Sirbu, Marvin/0000-0002-4424-2023 NR 22 TC 2 Z9 2 U1 1 U2 1 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0163-6804 J9 IEEE COMMUN MAG JI IEEE Commun. Mag. PD MAY PY 1997 VL 35 IS 5 BP 58 EP 62 DI 10.1109/35.592096 PG 5 WC Engineering, Electrical & Electronic; Telecommunications SC Engineering; Telecommunications GA WZ237 UT WOS:A1997WZ23700006 ER PT J AU Griffin, B Dymond, K KuntzmannCombelles, A Biggerstaff, T Varadan, G Kozaczynski, WV Murphy, M Draier, E Mackey, K AF Griffin, B Dymond, K KuntzmannCombelles, A Biggerstaff, T Varadan, G Kozaczynski, WV Murphy, M Draier, E Mackey, K TI Snapshots from industry SO IEEE SOFTWARE LA English DT News Item C1 GTE LABS INC,ADV SYST LAB,WALTHAM,MA 02254. PROC INC US,ANNAPOLIS,MD. PGCC TECHNOL,OBJECT TECHNOL,ARCUEIL,FRANCE. MICROSOFT,REDMOND,WA. GOVT INDIA,DEPT ELECT,BANGALORE,KARNATAKA,INDIA. BANGALORE SOFTWARE TECHNOL PK,BANGALORE,KARNATAKA,INDIA. SYST SOFTWARE ASSOCIATES,BPCS,CHICAGO,IL. SANDIA NATL LABS,ALBUQUERQUE,NM 87185. NETSYST SA,BUENOS AIRES,DF,ARGENTINA. LOCKHEED MARTIN ADV CONCEPTS CTR,SUNNYVALE,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1314 SN 0740-7459 J9 IEEE SOFTWARE JI IEEE Softw. PD MAY-JUN PY 1997 VL 14 IS 3 BP 112 EP & PG 4 WC Computer Science, Software Engineering SC Computer Science GA WX685 UT WOS:A1997WX68500030 ER PT J AU Ducharme, A Daniels, A Grann, E Boreman, G AF Ducharme, A Daniels, A Grann, E Boreman, G TI Design of an integrating sphere as a uniform illumination source SO IEEE TRANSACTIONS ON EDUCATION LA English DT Article DE integrating sphere; optics; optoelectronics; radiometry AB The design and fabrication of an integrating sphere to provide a uniform illumination source was the basis for a student laboratory project. The design process emphasizes several important concepts in radiometry. An integrating sphere is a useful component for other student laboratory experiments, and the design presented is cost-effective when compared with commercially available products. C1 PACIFIC SIERRA RES CORP,SANTA MONICA,CA 90405. OAK RIDGE NATL LAB,OAK RIDGE,TN 37932. UNIV CENT FLORIDA,DEPT ELECT ENGN,CTR RES & EDUC OPT & LASERS,ORLANDO,FL 32816. RP Ducharme, A (reprint author), VISIDYNE INC,BURLINGTON,MA 01803, USA. NR 5 TC 6 Z9 6 U1 1 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0018-9359 J9 IEEE T EDUC JI IEEE Trans. Educ. PD MAY PY 1997 VL 40 IS 2 BP 131 EP 134 DI 10.1109/13.572326 PG 4 WC Education, Scientific Disciplines; Engineering, Electrical & Electronic SC Education & Educational Research; Engineering GA WX310 UT WOS:A1997WX31000002 ER PT J AU Carlsten, BE Ferguson, P AF Carlsten, BE Ferguson, P TI Numerical determination of the matching conditions and drive characteristics for a klystron input cavity with beam SO IEEE TRANSACTIONS ON ELECTRON DEVICES LA English DT Article AB A numerical approach based on a cavity/drive circuit model and a numerical calculation of the beam impedance is outlined that self-consistently determines the modulation of a klystron input cavity for an arbitrary coupling of the rf source to the cavity and arbitrary cavity parameters, The model is fully defined by the cavity R/Q factor, resonant frequency, rf field distribution as determined by an rf cavity simulation, unloaded cavity Q, and externally-loaded Q without beam, We find an expression for the power required to maintain a desired steady-state input cavity modulation with beam for both the case when the coupling is perfectly matched to the rf drive, and also for the case of arbitrary coupling, In addition, we find expressions for the cavity detuning and externally-loaded Q that, if satisfied, lead to the optimum matching condition, This formalism is especially useful for high-power, relativistic klystrons, where the beam loading can be large and nonlinear, Examples are given for an X-band cavity, An extension of this approach to accelerator cavities is presented. C1 MDS CO,OAKLAND,CA 94611. RP Carlsten, BE (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 7 TC 7 Z9 7 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 0018-9383 J9 IEEE T ELECTRON DEV JI IEEE Trans. Electron Devices PD MAY PY 1997 VL 44 IS 5 BP 894 EP 900 DI 10.1109/16.568055 PG 7 WC Engineering, Electrical & Electronic; Physics, Applied SC Engineering; Physics GA WV648 UT WOS:A1997WV64800030 ER PT J AU Muljadi, E AF Muljadi, E TI PV water pumping with a peak-power tracker using a simple six-step square-wave inverter SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT IEEE Industry-Applications-Society Annual Meeting CY OCT 06-10, 1996 CL SAN DIEGO, CA SP IEEE, Ind Applicat Soc DE peak-power tracker; photovoltaic; PV array; renewable energy; village electrification; water pumping AB The application of photovoltaics (PV's) has been increasingly popular, especially in remote areas, where power from a utility is not available or is too costly to install, PV-powered water pumping Is frequently used for agriculture and in households. Among many available schemes, the system under study consists of a PV array, a variable-frequency inverter, an induction motor, and a water pump. The inverter feeds the induction motor, which drives the water pump. To seek the optimum power output of the PV array, the inverter is operated at variable frequency, to vary the output of the water pump. The inverter is operated to generate a six-step quasi-square wave, instead of a pulsewidth modulated (PWM) voltage output, to reduce the switching losses. The inverter acts as both a variable-frequency source and a peak-power tracker of the system, thus, having the number of switches minimized. The system is a low-cost design, with a simple control strategy. The de bus is supported by a de capacitor; thus, a balance-of-power how must be maintained to avoid the collapse of the de-bus voltage. Another advantage of the system is that the current is limited to an upper limit of the PV-array current. Thus, in case a short circuit is developed, the motor winding and the power semiconductor switches can be protected against excessive current pow. RP Muljadi, E (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 9 TC 28 Z9 28 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD MAY-JUN PY 1997 VL 33 IS 3 BP 714 EP 721 DI 10.1109/28.585862 PG 8 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA XA740 UT WOS:A1997XA74000017 ER PT J AU Peng, FZ Lai, JS AF Peng, FZ Lai, JS TI Dynamic performance and control of a static var generator using cascade multilevel inverters SO IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS LA English DT Article; Proceedings Paper CT IEEE Industry-Applications-Society Annual Meeting CY OCT 06-10, 1996 CL SAN DIEGO, CA SP IEEE, Ind Applicat Soc DE multilevel inverter; static var generator ID REACTIVE-POWER; COMPENSATION AB A cascade multilevel inverter is proposed for static var compensation/generation applications. The new cascade M-level inverter consists of (M-1)/2 single-phase full bridges in which each bridge has its own separate de source, This inverter can generate almost sinusoidal waveform voltage with only one time switching per cycle. It can eliminate the need for transformers in multipulse inverters. A prototype static var generator (SVG) system using 11-level cascade inverter (21-level line-to-line voltage waveform) has been built, The output voltage waveform is equivalent to that of a 60-pulse inverter. This paper focuses on dynamic performance of the cascade-inverter-based SVG system. Control schemes are proposed to achieve a fast response which is impossible for a conventional static var compensator (SVC). Analytical, simulated, and experimental results show the superiority of the proposed SVG system. C1 VIRGINIA POLYTECH INST & STATE UNIV, BRADLEY DEPT ELECT ENGN, VIRGINIA POWER ELECT CTR, BLACKSBURG, VA 24061 USA. RP Peng, FZ (reprint author), OAK RIDGE NATL LAB, ENGN TECHNOL DIV, OAK RIDGE, TN 37831 USA. OI Lai, Jihsheng/0000-0003-2315-8460 NR 14 TC 116 Z9 155 U1 0 U2 4 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI PISCATAWAY PA 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA SN 0093-9994 J9 IEEE T IND APPL JI IEEE Trans. Ind. Appl. PD MAY-JUN PY 1997 VL 33 IS 3 BP 748 EP 755 PG 8 WC Engineering, Multidisciplinary; Engineering, Electrical & Electronic SC Engineering GA XA740 UT WOS:A1997XA74000020 ER PT J AU Baldick, R Kahn, E AF Baldick, R Kahn, E TI Contract paths, phase-shifters, and efficient electricity trade SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article ID TRANSMISSION AB Phase-shifting transformers offer the opportunity to partially control the flows in an electricity network. In the US electricity industry, these devices currently operate under decentralized private ownership. This pattern, coupled with a commercial trading regime based on the contract path concept, creates potential inefficiencies. This paper illustrates the basic interactions in a simple four node model based broadly on conditions in the WSCC region. In addition to the potential inefficiencies of decentralized phase-shifter operation, we also show how they can enhance the overall utilization of the network. We compare regulatory approaches to managing these issues with more extensive structural reform of electricity trade. C1 LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. RP Baldick, R (reprint author), UNIV TEXAS, AUSTIN, TX 78712 USA. NR 13 TC 23 Z9 28 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 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD MAY PY 1997 VL 12 IS 2 BP 749 EP 755 DI 10.1109/59.589670 PG 7 WC Engineering, Electrical & Electronic SC Engineering GA WW130 UT WOS:A1997WW13000045 ER PT J AU Eto, J Moezzi, M AF Eto, J Moezzi, M TI Metered residential cooling loads: Comparison of three models SO IEEE TRANSACTIONS ON POWER SYSTEMS LA English DT Article ID DEMAND AB End-use metered data collected for five years from 350 California residences are used to compare three types of models for allocating estimates of annual residential central air conditioning energy use to hours of the year. We assess how well the model fits the data for daily energy, peak demand, and demand coincident with system peak. A model which couples regression-based functions for daily load estimation with hourly estimation according to a library of load profiles is judged to have a slightly better fit to the data than a model that estimates hourly loads directly from hourly functions derived from linear regressions. Concerns regarding the applicability of end-use metered data for long-term resource planning are described. RP Eto, J (reprint author), LAWRENCE BERKELEY LAB,UTIL POLICY & PLANNING GRP,ENERGY ANAL PROGRAM,ENERGY & ENVIRONM DIV,BERKELEY,CA 94720, USA. NR 23 TC 4 Z9 4 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 0885-8950 J9 IEEE T POWER SYST JI IEEE Trans. Power Syst. PD MAY PY 1997 VL 12 IS 2 BP 858 EP 868 DI 10.1109/59.589727 PG 11 WC Engineering, Electrical & Electronic SC Engineering GA WW130 UT WOS:A1997WW13000061 ER PT J AU Wang, D Czernik, S Montane, D Mann, M Chornet, E AF Wang, D Czernik, S Montane, D Mann, M Chornet, E TI Biomass to hydrogen via fast pyrolysis and catalytic steam reforming of the pyrolysis oil or its fractions SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID COPPER-BASED CATALYSTS; METHANOL; MECHANISM; ETHANOL; NICKEL; WATER AB Pyrolysis of lignocellulosic biomass and reforming of the pyroligneous oils are being studied as a strategy for producing hydrogen. A process of this nature has the potential to be cost competitive with conventional means of producing hydrogen. We propose a regionalized system of hydrogen production, where small- and medium-sized pyrolysis units (< 500 Mg/day) provide bio-oil to a central reforming unit to be catalytically converted to H-2 and CO2. Thermodynamic modeling of the major constituents of the bio-oil has shown that reforming is possible within a wide range of temperatures and steam-to-carbon ratios. In addition, screening tests aimed at catalytic reforming of model compounds to hydrogen using Ni-based catalysts have achieved essentially complete conversion to Ha. Existing data on the catalytic reforming of oxygenates have been studied to guide catalyst selection. A process diagram for the pyrolysis and reforming operations is discussed, as are initial production cost estimates. A window of opportunity clearly exists if the bio-oil is first refined to yield valuable oxygenates so that only a residual fraction is used for hydrogen production. C1 NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401. UNIV SHERBROOKE,SHERBROOKE,PQ J1K 2R1,CANADA. RI Montane, Daniel/K-9172-2014 OI Montane, Daniel/0000-0002-5273-8870 NR 49 TC 305 Z9 320 U1 1 U2 55 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 MAY PY 1997 VL 36 IS 5 BP 1507 EP 1518 DI 10.1021/ie960396g PG 12 WC Engineering, Chemical SC Engineering GA WX916 UT WOS:A1997WX91600017 ER PT J AU Proesmans, PI Luan, L Buelow, SJ AF Proesmans, PI Luan, L Buelow, SJ TI Hydrothermal oxidation of organic wastes using ammonium nitrate SO INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH LA English DT Article ID SUPERCRITICAL-WATER; HIGH-TEMPERATURE; CARBON-MONOXIDE; KINETICS; DECOMPOSITION; MIXTURES; NITROGEN AB The use of ammonium nitrate as an oxidizing agent in hydrothermal oxidation of organic compounds was investigated. The oxidation of model compounds, methanol, acetic acid, and phenol, was studied at 500 degrees C and 345 bar. High organic, ammonia, and nitrate removal was achieved at stoichiometric concentrations. The oxidation of ammonia by nitrate was much faster than the oxidation of either methanol or acetic acid and only slightly faster than phenol. Nitrogen products included N-2, N2O, and NO2- as well as toxic NO and trace amounts of NO2. Carbon products were CO2, HCO3-, CO32-, and CO. The co-oxidant system with hydrogen peroxide and ammonium nitrate was studied to eliminate the NOx production. Stoichiometric concentrations of hydrogen peroxide to the carbon concentrations resulted in undetectable NOx levels. C1 LOS ALAMOS NATL LAB,CHEM SCI & TECHNOL DIV,LOS ALAMOS,NM 87545. NR 24 TC 13 Z9 14 U1 6 U2 12 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 MAY PY 1997 VL 36 IS 5 BP 1559 EP 1566 DI 10.1021/ie9601716 PG 8 WC Engineering, Chemical SC Engineering GA WX916 UT WOS:A1997WX91600024 ER PT J AU DeBoer, RJ Perelson, AS AF DeBoer, RJ Perelson, AS TI Competitive control of the self-renewing T cell repertoire SO INTERNATIONAL IMMUNOLOGY LA English DT Article DE competition; competitive exclusion; mathematical model; repertoire selection; T cell numbers ID HOMEOSTATIC REGULATION; LYMPHOCYTES-T; LIFE-SPAN; MEMORY; MICE; EXCLUSION; ANTIGEN; REGENERATION; POPULATIONS; DEPENDENCE AB We develop a mathematical model for the self-renewing part of the T cell repertoire. Assuming that self-renewing T cells have to be stimulated by immunogenic MHC-peptide complexes presented on the surfaces of antigen-presenting cells, we derive a model of T cell growth in which competition for MHC-peptide complexes limits T cell clone sizes and regulates the total number of self-renewing T cells in the animal. We show that for a sufficient diversity and/or degree of crossreactivity, the total T cell number hardly depends upon the diversity of the T cell repertoire or the diversity of the set of presented peptides. Conversely, for repertoires of lower diversity and/or cross-reactivity, steady-state total T cell numbers may be limited by the diversity of the T cells. This provides a possible explanation for the limited repertoire expansion in some, but not all, mouse T cell re-constitution experiments. We suggest that the competitive interactions described by our model underlie the normal T cells numbers observed in transgenic mice, germ-free mice and various knockout mice. C1 LOS ALAMOS NATL LAB,DIV THEORET,MS K710,LOS ALAMOS,NM 87545. RP DeBoer, RJ (reprint author), UNIV UTRECHT,PADUALAAN 8,NL-3584 CH UTRECHT,NETHERLANDS. RI De Boer, Rob/B-6050-2011 OI De Boer, Rob/0000-0002-2130-691X FU NCRR NIH HHS [RR06555]; NIAID NIH HHS [AI28433] NR 54 TC 34 Z9 35 U1 0 U2 1 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD, ENGLAND OX2 6DP SN 0953-8178 J9 INT IMMUNOL JI Int. Immunol. PD MAY PY 1997 VL 9 IS 5 BP 779 EP 790 DI 10.1093/intimm/9.5.779 PG 12 WC Immunology SC Immunology GA XD240 UT WOS:A1997XD24000016 PM 9184924 ER PT J AU Dominguez, D Bishop, AR GronbechJensen, N AF Dominguez, D Bishop, AR GronbechJensen, N TI Coherence and complexity in condensed matter: Josephson junction arrays SO INTERNATIONAL JOURNAL OF BIFURCATION AND CHAOS LA English DT Review ID HIGH-TEMPERATURE SUPERCONDUCTORS; MELTING TRANSITION; UNTWINNED YBA2CU3O7; SINGLE-CRYSTALS; MAGNETIC-FIELD; VORTEX-LATTICE; MIXED-STATE; MODEL; VORTICES; LIQUID AB The importance of the mesoscopic bridge between microscopic and mesoscopic descriptions of complex, nonlinear-nonequilibrium extended dynamical systems is illustrated in a condensed matter context through three-dimensional Josephson junction arrays. Large-scale Langevin molecular dynamics is used to study novel transformer and melting effects, emphasizing the central roles of topological excitations (flux vortex lines) in determining mesoscopic patterns and dynamics - through flux line creation, annihilation, interaction and statistical mechanics. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. RP Dominguez, D (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,MS B262,LOS ALAMOS,NM 87545, USA. RI Dominguez, Daniel/E-9304-2016 OI Dominguez, Daniel/0000-0002-6204-0150 NR 41 TC 2 Z9 2 U1 0 U2 1 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0218-1274 J9 INT J BIFURCAT CHAOS JI Int. J. Bifurcation Chaos PD MAY PY 1997 VL 7 IS 5 BP 979 EP 988 DI 10.1142/S0218127497000790 PG 10 WC Mathematics, Interdisciplinary Applications; Multidisciplinary Sciences SC Mathematics; Science & Technology - Other Topics GA XZ655 UT WOS:A1997XZ65500002 ER PT J AU Stauffer, PH Auer, LH Rosenberg, ND AF Stauffer, PH Auer, LH Rosenberg, ND TI Compressible gas in porous media: A finite amplitude analysis of natural convection SO INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER LA English DT Article AB The theory of thermally driven convection of dry air in a porous medium is reviewed. The critical Rayleigh number for air is the same as for liquid, 4 pi(2), but the thermal gradient used is decreased by the adiabatic gradient of air. Because of the differences in the physical properties of air and water, initiation of convection requires the product of gradient and permeability to be thousands of times greater for air than for water. Finite amplitude analysis of the problem for Ra < 300 shows that: (1) the code predicts the onset of convection in an air filled porous medium; (2) at low thermal gradient, Ra vs Nu curves are nearly the same for air and water; (3) the slope of the Ra vs Nu curve matches well with experimental data reported by others for water; (4) time to steady state decreases approximately as the square root of Nusselt number. Copyright (C) 1996 Elsevier Science Ltd. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM. RP Stauffer, PH (reprint author), UNIV CALIF SANTA CRUZ,EARTH SCI BOARD,SANTA CRUZ,CA 95064, USA. OI Stauffer, Philip/0000-0002-6976-221X NR 14 TC 11 Z9 11 U1 0 U2 3 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 MAY PY 1997 VL 40 IS 7 BP 1585 EP 1589 DI 10.1016/S0017-9310(96)00222-0 PG 5 WC Thermodynamics; Engineering, Mechanical; Mechanics SC Thermodynamics; Engineering; Mechanics GA WC115 UT WOS:A1997WC11500010 ER PT J AU Groenewold, GS Delmore, JE Olson, JE Appelhans, AD Ingram, JC Dahl, DA AF Groenewold, GS Delmore, JE Olson, JE Appelhans, AD Ingram, JC Dahl, DA TI Secondary ion mass spectrometry of sodium nitrate: Comparison of ReO4- and Cs+ primary ions SO INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES LA English DT Article DE secondary ion mass spectrometry; perrhenate; cesium; sputter yield; disappearance cross section ID MATRIX AB The use of perrhenate (rhenium tetroxide, ReO4-) as a bombarding particle was compared with Cs+ for its ability to generate molecular species from sodium nitrate. The purpose of the study was to quantitatively evaluate the enhancement in sputtering to be gained using a heavy, polyatomic primary particle. It was found that ReO4- is three to five times more efficient at generating ions such as Na2NO3+ and Na(NO3)(2)(-). The nitrate-bearing molecular ions were observed to decrease in intensity as primary ion dose increases; at the same time, nitrite-bearing ions were observed to increase. This observation is interpreted in terms of beam damage to the surface of the target. Disappearance cross sections (sigma) using ReO4- bombardment were measured as 960 and 690 Angstrom(2) for Na2NO3+ and Na(NO3)(2)(-), respectively. sigma values measured using Cs+ bombardment were slightly larger. These measurements show that for an equivalent area of the sample disrupted, ReO4- is more effective for the production of nitrate-bearing secondary ions, which increases the probability of completing a measurement before extensive beam damage occurs. Secondary ion energies were evaluated and shown to be comparable for the ReO4- and Cs+ bombardment experiments; for this reason, sample charging is not deemed to be a significant factor in these experiments. (C) 1997 Elsevier Science B.V. RP Groenewold, GS (reprint author), IDAHO NATL ENGN LAB,IDAHO FALLS,ID 83415, USA. NR 17 TC 45 Z9 45 U1 1 U2 4 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 MAY PY 1997 VL 163 IS 3 BP 185 EP 195 DI 10.1016/S0168-1176(97)00017-7 PG 11 WC Physics, Atomic, Molecular & Chemical; Spectroscopy SC Physics; Spectroscopy GA XJ545 UT WOS:A1997XJ54500004 ER PT J AU Hayes, EM Jurrat, R Pu, R Snyder, RD Feld, SA Stanko, P Wilmsen, CW Choquette, KD Geib, KM Hou, HQ AF Hayes, EM Jurrat, R Pu, R Snyder, RD Feld, SA Stanko, P Wilmsen, CW Choquette, KD Geib, KM Hou, HQ TI Foundary fabricated array of smart pixels integrating MESFETs/MSMs and VCSELs SO INTERNATIONAL JOURNAL OF OPTOELECTRONICS LA English DT Article ID SURFACE-EMITTING LASER AB We have developed a process for the integration of vertical cavity surface emitting lasers (VCSELs) with foundry fabricated integrated circuits using a co-planar flip-chip bump-bonding process. Metal-semiconductor-metal (MSMs) photodetectors are fabricated directly onto the integrated circuit through the Vitesse 1.0 mu m E/D MESFET process along with the logic and VCSEL drivers. This technique can be used for the fabrication of OEICs by integrating VCSELs and photodetectors into an array of smart pixels, allowing much faster throughput than wire-bonding hybrid approaches. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Hayes, EM (reprint author), COLORADO STATE UNIV,DEPT ELECT ENGN,FT COLLINS,CO 80523, USA. NR 14 TC 12 Z9 12 U1 0 U2 0 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0952-5432 J9 INT J OPTOELECTRON JI Int. J. Optoelectron. PD MAY-JUN PY 1997 VL 11 IS 3 BP 229 EP 237 PG 9 WC Engineering, Electrical & Electronic; Optics SC Engineering; Optics GA YG212 UT WOS:A1997YG21200007 ER PT J AU Castro, JR Phillips, TL Prados, M Gutin, P Larson, DA Petti, PL Daftari, IK Collier, JM LillisHearne, P AF Castro, JR Phillips, TL Prados, M Gutin, P Larson, DA Petti, PL Daftari, IK Collier, JM LillisHearne, P TI Neon heavy charged particle radiotherapy of glioblastoma of the brain SO INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS LA English DT Article DE neon heavy charged particles; glioblastoma; neutron capture therapy ID NEUTRON-CAPTURE THERAPY; TRIAL AB Purpose: High-linear energy transfer (LET) radiation beams have potential applications in the treatment of glioblastoma, but have not yet demonstrated significant improvement in results. However, some patients have had local control of glioblastoma with high-LET irradiations such as neutrons and heavy charged particles. Methods and Materials: In this collaborative study, 15 patients were entered into a randomized protocol comparing two dose levels of 20 and 25 Gy in 4 weeks of neon ion irradiation. This trial was intended to determine the optimal neon dose in terms of survival and effects of radiation. Results: Fourteen patients were evaluable with no significant differences in median survival (13 and 14 months; p = NS) or median time to failure (7 and 9 months; p = NS) between the two dose arms. Three patients died of nontumor-related causes, of whom one (who died 19 months posttreatment) had autopsy confirmation of no tumor on pathological exam. The other two patients had stable magnetic resonance imaging scans at 6 and 22 months posttreatment. Conclusion: Although the results did not demonstrate the optimal high-LET dose level, there is an intriguing effect in that two patients had control of glioblastoma until death at 19 and 22 months. This suggests that better conformation of the high-LET dose to the tumor with neutron capture therapy or dynamic conformal heavy charged particle therapy might control glioblastoma while minimizing brain damage from radiation. (C) 1997 Elsevier Science Inc. C1 UNIV CALIF SAN FRANCISCO,MED CTR,DEPT RADIAT ONCOL,SAN FRANCISCO,CA 94143. UNIV CALIF SAN FRANCISCO,MED CTR,DEPT NEUROL,SAN FRANCISCO,CA 94143. RP Castro, JR (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY NATL LAB,DIV LIFE SCI,MS 55-121,BERKELEY,CA 94720, USA. FU NCI NIH HHS [CA19138] NR 17 TC 21 Z9 22 U1 0 U2 1 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 MAY 1 PY 1997 VL 38 IS 2 BP 257 EP 261 DI 10.1016/S0360-3016(97)00039-4 PG 5 WC Oncology; Radiology, Nuclear Medicine & Medical Imaging SC Oncology; Radiology, Nuclear Medicine & Medical Imaging GA XJ938 UT WOS:A1997XJ93800005 PM 9226311 ER PT J AU Anderson, GK AF Anderson, GK TI An optical technique for in situ density determination in electrolyte solutions under hydrothermal conditions SO INTERNATIONAL JOURNAL OF THERMOPHYSICS LA English DT Article DE density; electrolyte solutions; high pressure; high temperature; hydrothermal; refractive index AB We report on a technique which determines the density of hydrothermal solutions through the relationship between density and refractive index given by the Lorentz-Lorenz equation. An optical cell is described which allows the refractive index of fluids to be measured at temperatures up to 823 K and pressures up to 1200 bar. The validity of the Lorentz-Lorenz equation is demonstrated for pure water and water/NaCl solutions. New experimental results are presented for the density of water/NaNO3 solutions at high temperature and pressure. The use of density data to derive other properties such as compressibility, thermal expansion coefficient, and apparent molar volume is demonstrated. RP Anderson, GK (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 15 TC 4 Z9 4 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0195-928X J9 INT J THERMOPHYS JI Int. J. Thermophys. PD MAY PY 1997 VL 18 IS 3 BP 699 EP 717 DI 10.1007/BF02575129 PG 19 WC Thermodynamics; Chemistry, Physical; Mechanics; Physics, Applied SC Thermodynamics; Chemistry; Mechanics; Physics GA XK364 UT WOS:A1997XK36400005 ER PT J AU Conger, R Hattrup, M AF Conger, R Hattrup, M TI US DOE programs team to give a boost to the aluminum industry SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article RP Conger, R (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAY PY 1997 VL 49 IS 5 BP 15 EP 15 DI 10.1007/BF02914674 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA WX315 UT WOS:A1997WX31500002 ER PT J AU Swink, DF Sousa, LJ AF Swink, DF Sousa, LJ TI About the OIT and IOF SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article RP Swink, DF (reprint author), US DOE,OFF IND TECHNOL,WASHINGTON,DC 20585, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAY PY 1997 VL 49 IS 5 BP 15 EP 15 PG 1 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA WX315 UT WOS:A1997WX31500003 ER PT J AU Keicher, DM Smugeresky, JE AF Keicher, DM Smugeresky, JE TI The laser forming of metallic components using particulate materials SO JOM-JOURNAL OF THE MINERALS METALS & MATERIALS SOCIETY LA English DT Article AB Direct fabrication technology, which utilizes computer-aided design solid models to automatically control the manufacture of functional piece parts, is rapidly gaining popularity as a means to significantly reduce the time to market of new concepts. Since the introduction of stereolithography in 1982, several different vapid prototyping technologies have evolved using surrogate rather than actual materials of construction. Most recently, researchers have begun to develop laser-based methods to obtain fully dense metallic components directly from a computer-aided design solid model. Each of these methods is unique, but possesses aspects that ave similar to the others. Many of these methods hold a great deal of promise for applications; however, none have been developed into a commercial product. C1 SANDIA NATL LABS, TECH STAFF, LIVERMORE, CA 94550 USA. RP Keicher, DM (reprint author), OPTOMEC DESIGN CO, DIRECT MET DEPOSIT, 13170-B CENT AVE SE, SUITE 310, ALBUQUERQUE, NM 87123 USA. NR 25 TC 44 Z9 51 U1 1 U2 6 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 184 THORN HILL RD, WARRENDALE, PA 15086 USA SN 1047-4838 J9 JOM-J MIN MET MAT S JI JOM-J. Miner. Met. Mater. Soc. PD MAY PY 1997 VL 49 IS 5 BP 51 EP 54 DI 10.1007/BF02914686 PG 4 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing SC Materials Science; Metallurgy & Metallurgical Engineering; Mineralogy; Mining & Mineral Processing GA WX315 UT WOS:A1997WX31500015 ER PT J AU Gwizdala, AB Johnson, SK Mollah, S Houk, RS AF Gwizdala, AB Johnson, SK Mollah, S Houk, RS TI Speciation of chromium(VI) and chromium(III) using pneumatically assisted electrospray mass spectrometry SO JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY LA English DT Article DE chromium determination; speciation; electrospray; ion spray; mass spectrometry ID ELEMENTAL ANALYSIS; IONIZATION; INTERFACE; PROTEINS; IONS AB Mass spectra can be obtained from aqueous solutions containing both Cr3+ and Cr2O72- as negative ions under the same spray conditions. An excess of HCl is used so that Cr3+ sprays as an anionic chloro complex. Moderately energetic collision conditions produce CrO3- from Cr-VI and CrOCl2- from Cr-III. Detection limits are 100 and 60 ppb for Cr-III and Cr-VI, respectively. Reasonable calibration curves are provided by plotting the ratio of the analyte signal to that for Cl-37(-). C1 IOWA STATE UNIV,DEPT CHEM,US DOE,AMES LAB,AMES,IA 50011. NR 22 TC 33 Z9 33 U1 0 U2 4 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 MAY PY 1997 VL 12 IS 5 BP 503 EP 506 DI 10.1039/a606413b PG 4 WC Chemistry, Analytical; Spectroscopy SC Chemistry; Spectroscopy GA WZ818 UT WOS:A1997WZ81800003 ER PT J AU Woodworth, JR Riley, ME Miller, PA Hebner, GA Hamilton, TW AF Woodworth, JR Riley, ME Miller, PA Hebner, GA Hamilton, TW TI Ion energy and angular distributions in inductively driven radio frequency discharges in chlorine SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID RF REFERENCE CELL; RADIOFREQUENCY GLOW-DISCHARGES; POWERED ELECTRODE; PLASMA SOURCE; BOMBARDMENT; MODEL; AR AB In this article, we report values of ion energy and angular distributions measured at the grounded electrode of an inductively coupled discharge in chlorine gas. The inductive rf drive in our cell produced high plasma densities (10(11)/cm(3) electron densities) and stable plasma potentials. As a result, ion energy distributions typically consisted of a single peak well separated from zero energy, Mean ion energy varied inversely with pressure, decreasing from 13 to 9 eV as the discharge pressure increased from 20 to 60 mTorr. Half-widths of the ion angular distributions In these experiments varied from 6 degrees to 7.5 degrees, corresponding to transverse energies from 0.13 to 0.21 eV. During the course of the experiment, ion energies gradually decreased, probably due to the buildup of contaminants on the chamber walls. Cell wall temperature also was an important variable, with ion fluxes to the lower electrode increasing and the ion angular distribution narrowing as the cell temperature increased. (C) 1997 American Institute of Physics. C1 APPL PHYS INT INC,ALBUQUERQUE,NM 87110. RP Woodworth, JR (reprint author), SANDIA NATL LABS,DEPT LASER OPT & REMOTE SENSING,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 46 TC 52 Z9 52 U1 0 U2 5 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 MAY 1 PY 1997 VL 81 IS 9 BP 5950 EP 5959 DI 10.1063/1.364383 PG 10 WC Physics, Applied SC Physics GA WW729 UT WOS:A1997WW72900012 ER PT J AU Falkenstein, Z AF Falkenstein, Z TI Influence of ultraviolet illumination on microdischarge behavior in dry and humid N-2, O-2, air, and Ar/O-2: The Joshi effect SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID DIELECTRIC-BARRIER DISCHARGE; PLASMAS AB The influence of UV illumination on the behavior of silent electrical discharge streamers (microdischarges) in dry and humid gases (nitrogen, oxygen, air, and Ar/O-2 mixtures) is presented. A commercial low-pressure mercury lamp, which was spectrally calibrated, provides UV light. The UV irradiance power coupled into the discharge cell is also calculated. The transferred charge per mean microdischarge (in a voltage half-cycle) was measured for a pin electrode assembly, configured to deliver either M-G+ transitions (electrons going from metal towards dielectric) or M+G- transitions (electrons going from dielectric to metal). The total transferred charge is recorded by monitoring a charge versus voltage plot (Lissajous figure). When illumination is restricted to the gas alone, both the total transferred charge and the individual-microdischarge transferred charge remain constant for either transition (M-G+ or M+G-). However, when the dielectric is illuminated, a marked decrease in the individual-microdischarge transferred charge is observed for M+G- transitions in some gases. For this case, a greater number of microdischarges must occur in a half-cycle to keep the total transferred charge constant, thereby creating more homogeneous discharge conditions. (C) 1997 American Institute of Physics. RP Falkenstein, Z (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 24 TC 18 Z9 19 U1 1 U2 5 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 MAY 1 PY 1997 VL 81 IS 9 BP 5975 EP 5979 DI 10.1063/1.364386 PG 5 WC Physics, Applied SC Physics GA WW729 UT WOS:A1997WW72900015 ER PT J AU Stolk, PA Gossmann, HJ Eaglesham, DJ Jacobson, DC Rafferty, CS Gilmer, GH Jaraiz, M Poate, JM Luftman, HS Haynes, TE AF Stolk, PA Gossmann, HJ Eaglesham, DJ Jacobson, DC Rafferty, CS Gilmer, GH Jaraiz, M Poate, JM Luftman, HS Haynes, TE TI Physical mechanisms of transient enhanced dopant diffusion in ion-implanted silicon SO JOURNAL OF APPLIED PHYSICS LA English DT Review ID MOLECULAR-BEAM EPITAXY; SI THIN-FILMS; POINT-DEFECTS; BORON-DIFFUSION; INTERSTITIAL-CARBON; SELF-DIFFUSION; AMORPHIZATION THRESHOLD; CRYSTALLINE SILICON; RANGE DAMAGE; PHOSPHORUS AB Implanted B and P dopants in Si exhibit transient enhanced diffusion (TED) during annealing which arises from the excess interstitials generated by the implant, In order to study the mechanisms of TED, transmission electron microscopy measurements of implantation damage were combined with B diffusion experiments using doping marker structures grown by molecular-beam epitaxy (MBE). Damage from nonamorphizing Si implants at doses ranging from 5x10(12) to 1x10(14)/cm(2) evolves into a distribution of {311} interstitial agglomerates during the initial annealing stages at 670-815 degrees C. The excess interstitial concentration contained in these defects roughly equals the implanted ion dose, an observation that is corroborated by atomistic Monte Carlo simulations of implantation and annealing processes. The injection of interstitials from the damage region involves the dissolution of {311} defects during Ostwald ripening with an activation energy of 3.8+/-0.2 eV. The excess interstitials drive substitutional B into electrically inactive, metastable clusters of presumably two or three B atoms at concentrations below the solid solubility, thus explaining the generally observed immobile B peak during TED of ion-implanted B. Injected interstitials undergo retarded diffusion in the MBE-grown Si with an effective migration energy of similar to 3.5 eV, which arises from trapping at substitutional C. The concept of trap-limited diffusion provides a stepping stone for understanding the enormous disparity among published values for the interstitial diffusivity in Si. The population of excess interstitials is strongly reduced by incorporating substitutional C in Si to levels of similar to 10(19)/cm(3) prior to ion implantation. This provides a promising method for suppressing TED, thus enabling shallow junction formation in future Si devices through dopant implantation. The present insights have been implemented into a process simulator, allowing for a significant improvement of the predictive modeling of TED. (C) 1997 American Institute of Physics. C1 AT&T BELL LABS,LUCENT TECHNOL,MURRAY HILL,NJ 07974. AT&T BELL LABS,LUCENT TECHNOL,BREINIGSVILLE,PA 18031. OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RI Jaraiz, Martin/H-6061-2015; Haynes, Tony/P-8932-2015 OI Jaraiz, Martin/0000-0001-6688-3158; Haynes, Tony/0000-0003-2871-4745 NR 101 TC 512 Z9 515 U1 12 U2 116 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 MAY 1 PY 1997 VL 81 IS 9 BP 6031 EP 6050 DI 10.1063/1.364452 PG 20 WC Physics, Applied SC Physics GA WW729 UT WOS:A1997WW72900023 ER PT J AU Zhang, Y Mascarenhas, A Ernst, P Driessen, FAJM Friedman, DJ Bertness, KA Olson, JM Geng, C Scholz, F Schweizer, H AF Zhang, Y Mascarenhas, A Ernst, P Driessen, FAJM Friedman, DJ Bertness, KA Olson, JM Geng, C Scholz, F Schweizer, H TI Effects of strain, substrate misorientation, and excitonic transition on the optical polarization of ordered zinc-blende semiconductor alloys SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID LONG-RANGE-ORDER; REFLECTANCE-DIFFERENCE SPECTROSCOPY; ENERGY-LEVELS; BAND-GAP; GAINP2; PHOTOLUMINESCENCE; SUPERLATTICES; GA0.5IN0.5P; STATES AB Optical polarization in ordered GaInP2 alloys has been studied by low-temperature photoluminescence. A perturbative theory that includes the effects of lattice mismatch, substrate misorientation, and excitonic transitions has been developed for making quantitative comparisons between experimental results and theoretical predictions. We show that to obtain quantitative information about ordering from the polarization of near;band-gap transitions, all of the above-mentioned effects should be taken into account. This study demonstrates that the electronic and optical properties of a monolayer superlattice formed by partial ordering in the GaInP2 alloy can be well described by a simple perturbative Hamiltonian, i.e., a quasicubic model. (C) 1997 American Institute of Physics. C1 UNIV STUTTGART,INST PHYS 4,D-70550 STUTTGART,GERMANY. RP Zhang, Y (reprint author), NATL RENEWABLE ENERGY LAB,GOLDEN,CO 80401, USA. NR 37 TC 24 Z9 24 U1 0 U2 4 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 MAY 1 PY 1997 VL 81 IS 9 BP 6365 EP 6373 DI 10.1063/1.364390 PG 9 WC Physics, Applied SC Physics GA WW729 UT WOS:A1997WW72900071 ER PT J AU Irwin, RD Chou, BJ Mellick, PW Miller, RA Mahler, J Roycroft, J AF Irwin, RD Chou, BJ Mellick, PW Miller, RA Mahler, J Roycroft, J TI Toxicity of furfuryl alcohol to F344 rats and B6C3F(1) mice exposed by inhalation SO JOURNAL OF APPLIED TOXICOLOGY LA English DT Article DE furfuryl alcohol; inhalation; nasal lesions ID DOSE LEVELS; VAPOR; METABOLISM AB Groups of F344 rats and B6C3F(1) mice were exposed to furfuryl alcohol vapor for 6 hours per day, 5 days per week for 14 days (0, 16, 31, 63, 125, 250 ppm) or 13 weeks (0, 2, 4, 8, 16, 32 ppm). Reduced survival was observed in the 14-day study at 250 ppm. Final mean body weights of rats and mice exposed to 125 ppm and of female mice exposed to 63 ppm were lower than controls at the end of the 14-day study; there were no significant differences in mean body weight among chemical-exposed and control groups in the 13-week study. Exposure to furfuryl alcohol had no toxicologically significant effect on organ weights in either rats or mice, and did not cause any adverse changes in hematology or serum chemistry parameters evaluated in rats in the 13-week study. Microscopic lesions associated with exposure to furfuryl alcohol were present in the nose of both rats and mice at all exposure concentrations in both the 14-day and 13-week studies. Lesions observed in the 14-day study consisted of inflammation of the nasal turbinates accompanied by necrosis and squamous metaplasia of the respiratory epithelium and necrosis and degeneration of the olfactory epithelium. Similar lesions were observed in both rats and mice in the 13-week study. In addition, squamous metaplasia and goblet cell hyperplasia of the respiratory epithelium, squamous metaplasia of the transitional epithelium and degeneration, hyperplasia and some respiratory metaplasia of the olfactory epithelium were also observed in rats in the 13-week study, and hyaline droplets in the respiratory epithelium and chronic inflammation and respiratory metaplasia in the olfactory epithelium were observed in mice in the 13-week study. In general the nasal passages of mice appeared less sensitive than those of rats at the concentrations used in the 13-week study; a no-observable-effect level was not achieved in either the 14-day or the 13-week study. (C) 1997 by John Wiley & Sons, Ltd. C1 PACIFIC NW LAB, RICHLAND, WA USA. RP Irwin, RD (reprint author), NIEHS, POB 12233, RES TRIANGLE PK, NC 27709 USA. NR 19 TC 6 Z9 6 U1 0 U2 1 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0260-437X J9 J APPL TOXICOL JI J. Appl. Toxicol. PD MAY-JUN PY 1997 VL 17 IS 3 BP 159 EP 169 DI 10.1002/(SICI)1099-1263(199705)17:3<159::AID-JAT420>3.0.CO;2-E PG 11 WC Toxicology SC Toxicology GA XM162 UT WOS:A1997XM16200003 PM 9250537 ER PT J AU Fitzgerald, TJ AF Fitzgerald, TJ TI Observations of total electron content perturbations on GPS signals caused by a ground level explosion SO JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS LA English DT Article ID WAVES AB We have measured perturbations of electron density in the ionosphere caused by a ground level explosion with an energy release of 2 kt (8.5 x 10(12) J) using transmissions from Global Positioning System (GPS) satellites to monitor integrated electron density. The frequencies of the transmissions were 1575.42 MHz (L1) and 1227.60 MHz (L2). The detected perturbation showed a maximum excursion of 0.14 TEC units and had a duration of 80 s beginning at 565 s after the explosion. The acoustic disturbance necessary to produce such a perturbation is well modeled as an N wave with a dimension df 35 km and a relative amplitude of 12% propagating radially at a speed of 0.7 km/s. The majority of the TEC perturbation occurred at an altitude of approximately 200 km. (C) 1997 Elsevier Science Ltd. RP Fitzgerald, TJ (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 13 TC 39 Z9 43 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 1364-6826 J9 J ATMOS SOL-TERR PHY JI J. Atmos. Sol.-Terr. Phys. PD MAY PY 1997 VL 59 IS 7 BP 829 EP 834 DI 10.1016/S1364-6826(96)00105-8 PG 6 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences GA WP044 UT WOS:A1997WP04400008 ER PT J AU Elliott, S Shen, M Blake, DR Lu, R Russell, AG Kao, CYJ Streit, GE Zhao, XP McCreary, EI Rowland, FS Brown, MJ Turco, RP AF Elliott, S Shen, M Blake, DR Lu, R Russell, AG Kao, CYJ Streit, GE Zhao, XP McCreary, EI Rowland, FS Brown, MJ Turco, RP TI Atmospheric effects of the emerging mainland Chinese transportation system at and beyond the regional scale SO JOURNAL OF ATMOSPHERIC CHEMISTRY LA English DT Review DE Chinese vehicles; ozone; aerosols; carbon dioxide; alternative fuels ID TROPOSPHERIC OZONE PRODUCTION; HOSPITAL OUTPATIENT VISITS; WESTERN NORTH-ATLANTIC; AIR-POLLUTION; MEXICO-CITY; NITROGEN-OXIDES; UNITED-STATES; PACIFIC-OCEAN; FOSSIL-FUELS; TRACE GASES AB Local surface travel needs in the People's Republic of China (mainland China) have traditionally been met largely by nonpolluting bicycles. A major automobile manufacturing/importing effort has begun in the country over the last decade, and planning documents indicate that the Chinese may strive to acquire more than 100 million vehicles early in the next century. By analogy with large automotive fleets already existing in the western world, both regional and global scale pollution effects are to be expected from the increase. The present work adopts the latest projections of Chinese automobile manufacture and performs some quantitative assessments of the extent of pollution generation. Focus for the investigation is placed upon the oxidant ozone. Emissions of the precursor species nitrogen oxides and volatile organics are constructed based on data for the current automotive sector in the eastern portion of the United States. Ozone production is first estimated from measured values for continental/oceanic scale yields relative to precursor oxidation. The estimates are then corroborated through idealized two dimensional modeling of the photochemistry taking place in springtime air flow off the Asian land mass and toward the Pacific Ocean. The projected fleet sizes could increase coastal and remote oceanic ozone concentrations by tens of parts per billion (ppb) in the lower troposphere. Influences on the tropospheric aerosol system and on the major greenhouse gas carbon dioxide are treated peripherally. Nitrogen oxides created during the vehicular internal combustion process will contribute to nitrate pollution levels measured in the open Pacific. The potential for soot and fugitive dust increases should be considered as the automotive infrastructure develops. Since the emerging Chinese automotive transportation system will represent a substantial addition to the global fleet and all the carbon in gasoline is eventually oxidized completely, a significant rise in global carbon dioxide inputs will ensue as well. Some policy issues are treated preliminary The assumption is made that alterations to regional oxidant/aerosol systems and to terrestrial climate are conceivable. The likelihood that the Chinese can achieve the latest vehicle fleet goals is discussed, from the points of view of new production, positive pollution feedbacks from a growing automobile industry, and known petroleum reserves. Vehicular fuel and maintenance options lying before the Chinese are outlines and compared. To provide some perspective on the magnitude of the environmental changes associated with an Asian automotive buildup, recent estimates of the effects of future air traffic over the Pacific Rim are described. C1 LOS ALAMOS NATL LAB,DIV EARTH & ENVIRONM SCI,GEOANAL GRP,LOS ALAMOS,NM 87545. UNIV CALIF LOS ANGELES,DEPT ATMOSPHER SCI,LOS ANGELES,CA 90024. UNIV CALIF IRVINE,DEPT CHEM,IRVINE,CA 92715. GEORGIA INST TECHNOL,DEPT CIVIL ENGN,ATLANTA,GA 30033. LOS ALAMOS NATL LAB,TECHNOL & SAFETY ASSESSMENT DIV,ENERGY & ENVIRONM ANAL GRP,LOS ALAMOS,NM 87545. OI Brown, Michael J./0000-0002-8069-0835 NR 240 TC 11 Z9 12 U1 1 U2 11 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-7764 J9 J ATMOS CHEM JI J. Atmos. Chem. PD MAY PY 1997 VL 27 IS 1 BP 31 EP 70 DI 10.1023/A:1005726818613 PG 40 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA XQ266 UT WOS:A1997XQ26600003 ER PT J AU Kuritz, T Bocanera, LV Rivera, NS AF Kuritz, T Bocanera, LV Rivera, NS TI Dechlorination of lindane by the cyanobacterium Anabaena sp. strain PCC7120 depends on the function of the nir operon SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SYNECHOCOCCUS SP PCC7942; ANACYSTIS-NIDULANS; NITRATE REDUCTASE; GENE; NITRITE; IDENTIFICATION; TRANSPORT AB Nitrate is essential for lindane dechlorination by the cyanobacteria Anabaena sp, strain PCC7120 and Nostoc ellipsosporum, as it is for dechlorination of other organic compounds bg heterotrophic microorganisms. Based on analyses of mutants and effects of environmental factors, me conclude that lindane dechlorination by Anabaena sp. requires a functional nir operon that encodes the enzymes for nitrate utilization. RP Kuritz, T (reprint author), OAK RIDGE NATL LAB,DIV LIFE SCI,MS-6480,OAK RIDGE,TN 37830, USA. NR 28 TC 25 Z9 30 U1 1 U2 1 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 MAY PY 1997 VL 179 IS 10 BP 3368 EP 3370 PG 3 WC Microbiology SC Microbiology GA WY116 UT WOS:A1997WY11600041 PM 9150239 ER PT J AU Rizzo, P Albright, JG Miller, DG AF Rizzo, P Albright, JG Miller, DG TI Measurements of interdiffusion coefficients and densities for the system HCl+H2O at 25 degrees C SO JOURNAL OF CHEMICAL AND ENGINEERING DATA LA English DT Article ID DIFFUSION-COEFFICIENTS; PATTERNS AB Interdiffusion (mutual diffusion) coefficients have been measured by Gouy interferometry for the system HCl + H2O at 25 degrees C from 0.100 M to 11.991 M concentration. They vary from 3.336 x 10(-9) m(2) s(-1) at infinite dilution, to a minimum of about of 3.03 x 10(-9) m(2) s(-1) near 0.1 M, to a maximum of about 6.0 x 10(-9) m(2) s(-1) near 7.25 M, and back down to 4.306 x 10(-9) m(2) s(-1) at 11.99 M. Thermodynamic diffusion coefficients have been calculated and appear to decrease monotonically and smoothly from 3.3368 x 10(-9) m(2) s(-1) at infinite dilution to a value of 0.947 x 10(-9) m(2) s(-1) at 11.99 M. Densities of HCl solutions have been measured from 0.125 M to 12.186 M at 25 degrees C. These increase approximately linearly with molarity M from the density of pure water of 0.997 045 g cm(-3) to a density of 1.1827 g cm(-3) at 12.186 M. C1 TEXAS CHRISTIAN UNIV,DEPT CHEM,FT WORTH,TX 76129. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. RI rizzo, paola/I-3016-2012 NR 28 TC 14 Z9 14 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0021-9568 J9 J CHEM ENG DATA JI J. Chem. Eng. Data PD MAY-JUN PY 1997 VL 42 IS 3 BP 623 EP 630 DI 10.1021/je9603943 PG 8 WC Thermodynamics; Chemistry, Multidisciplinary; Engineering, Chemical SC Thermodynamics; Chemistry; Engineering GA WY825 UT WOS:A1997WY82500042 ER PT J AU Stevens, MJ Mondello, M Grest, GS Cui, ST Cochran, HD Cummings, PT AF Stevens, MJ Mondello, M Grest, GS Cui, ST Cochran, HD Cummings, PT TI Comparison of shear flow of hexadecane in a confined geometry and in bulk SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NONEQUILIBRIUM MOLECULAR-DYNAMICS; POLYMER MELTS; THIN-FILMS; SIMULATION; LIQUIDS; FLUIDS; MONOLAYER; BEHAVIOR; RHEOLOGY; ALKANES AB We examine the shear flow of hexadecane confined between plates with separation of 1-10 nm using molecular dynamics simulations. We also performed non-equilibrium molecular dynamics (NEMD) simulations of bulk hexadecane to compare with the simulations in the confined geometry. The stiffness of hexadecane and its high melting temperature result in a tendency to crystallize at room temperature or large load. We find that when confined between hydrocarbon walls, shearing hexadecane exhibits a velocity profile with substantial slip at the wall and essentially constant velocity over most of the interior space between the walls. As the strength of the wall-fluid interaction increases the amount of slip decreases, but slip always occurs at the boundary for the range of parameters studied. The results are compared with recent surface force apparatus experiments on hexadecane and with similar simulations of model bead-spring fluids. (C) 1997 American Institute of Physics. C1 EXXON RES & ENGN CO,CORP RES SCI LABS,ANNANDALE,NJ 08801. UNIV TENNESSEE,DEPT CHEM ENGN,KNOXVILLE,TN 37996. OAK RIDGE NATL LAB,DIV CHEM TECHNOL,OAK RIDGE,TN 37831. RP Stevens, MJ (reprint author), SANDIA NATL LABS,POB 5800,MS 1111,ALBUQUERQUE,NM 87185, USA. RI Cummings, Peter/B-8762-2013 OI Cummings, Peter/0000-0002-9766-2216 NR 57 TC 104 Z9 107 U1 0 U2 14 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 MAY 1 PY 1997 VL 106 IS 17 BP 7303 EP 7314 DI 10.1063/1.473692 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WV763 UT WOS:A1997WV76300053 ER PT J AU Rard, JA AF Rard, JA TI Isopiestic determination of the osmotic and activity coefficients of {zH(2)SO(4)+(1-z)MgSO4}(aq) at the temperature T=298.15 K .1. Results for z=(0.85811, 0.71539, and 0.57353) SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article DE isopiestic measurements; vapor pressures; aqueous solutions; sulfuric acid; magnesium sulfate ID AQUEOUS SULFURIC-ACID; MAGNESIUM-SULFATE SOLUTIONS; THERMODYNAMIC PROPERTIES; ELEVATED-TEMPERATURES; 25-DEGREES-C; 298.15-K; SYSTEM; ((1-Y)H2SO4+YNA2SO4)(AQ); EQUILIBRIA; SOLUBILITY AB Isopiestic vapor-pressure measurements were made for {zH(2)SO(4) + (1 - z)MgSO4}(aq) with H2SO4 molality fractions of z = (0.85811, 0.71539, and 0.57353) at the temperature 298.15 K. Measurements extend from total molalities m(T) of (0.12548, 0.13563, and 0.14741) mol.kg(-1) to the supersaturated molalities m(T) = (12.049(6), 11.011(2), and 7.2059(5)) mol.kg(-1), respectively. For z =(0.71539 and 0.57353) these highest molalities correspond to the greatest degrees of supersaturation that could be achieved during isothermal removal of the solvent. The corresponding water activity ranges are 0.9958 greater than or equal to a(w) greater than or equal to 0.2758, 0.9958 greater than or equal to a(w) greater than or equal to 0.3312, and 0.9958 greater than or equal to a(w) greater than or equal to 0.5581 for z = (0.85811, 0.71539, and 0.57353), respectively. These values of z were chosen to be separated approximately equally by 0.142 (Delta z approximate to 1/7). The water activity curves were also found to be nearly equally spaced from each other, as was the z = 0.85811 curve from that for H2SO4(aq) (z = 1). Given that both H2SO4(aq) and MgSO4(aq) are extensively associated electrolytes, this regularity in the mixing behavior was not anticipated. A well-defined crossover point was found at which the sums of the stoichiometric ionic molalities were equal at isopiestic equilibrium for z = (1,0.85811, 0.71539, and 0.57353), as were the water activities and stoichiometric osmotic coefficients of these solutions. This occurred at Sigma(i) nu(i)m(i) = (5.9632 +/- 0.0036) mol.kg(-1), where nu(i) is the stoichiometric ionization number of electrolyte i. (C) 1997 Academic Press Limited. RP Rard, JA (reprint author), LAWRENCE LIVERMORE NATL LAB,ENVIRONM PROGRAMS DIRECTORATE,LIVERMORE,CA 94550, USA. NR 40 TC 16 Z9 16 U1 1 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD MAY PY 1997 VL 29 IS 5 BP 533 EP 555 DI 10.1006/jcht.1996.0169 PG 23 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA XB733 UT WOS:A1997XB73300003 ER PT J AU OllivierGooch, CF AF OllivierGooch, CF TI Quasi-ENO schemes for unstructured meshes based on unlimited data-dependent least-squares reconstruction SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID ESSENTIALLY NONOSCILLATORY SCHEMES AB A crucial step in obtaining high-order accurate steady-state solutions to the Euler and Navier-Stokes equations is the high-order accurate reconstruction of the solution from cell-averaged values. Only after this reconstruction has been completed can the flux integral around a control volume be accurately assessed. In this work, a new reconstruction scheme is presented that is conservative, is uniformly accurate, allows only asymptotically small overshoots, is easy to implement on arbitrary meshes, has good convergence properties, and is computationally efficient. The new scheme, called DD-L-2-ENO, uses a data-dependent weighted least-squares reconstruction with a fixed stencil. The weights are chosen to strongly emphasize smooth data in the reconstruction, satisfying the weighted ENO conditions of Liu, Osher, and Chan. Because DD-L-2-ENO is designed in the framework of k-exact reconstruction, existing techniques for implementing such reconstructions on arbitrary meshes can be used. The scheme allows graceful degradation of accuracy in regions where insufficient smooth data exists for reconstruction of the requested high order. Similarities with and differences from WENO schemes are highlighted. The asymptotic behavior of the scheme in reconstructing smooth and piecewise smooth functions is demonstrated. DD-L-2-ENO produces uniformly high order accurate reconstructions, even in the presence of discontinuities. Results are shown for one-dimensional scalar propagation and shock tube problems. Encouraging preliminary hive-dimensional flow solutions obtained using DD-L-2-ENO reconstruction are also shown and compared with solutions using limited least-squares reconstruction. (C) 1997 Academic Press. RP ARGONNE NATL LAB, DIV MATH & COMP SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. RI Ollivier-Gooch, Carl/E-8934-2011 OI Ollivier-Gooch, Carl/0000-0001-6514-058X NR 14 TC 43 Z9 43 U1 1 U2 3 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 EI 1090-2716 J9 J COMPUT PHYS JI J. Comput. Phys. PD MAY 1 PY 1997 VL 133 IS 1 BP 6 EP 17 DI 10.1006/jcph.1996.5584 PG 12 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WX892 UT WOS:A1997WX89200002 ER PT J AU Rambo, PW AF Rambo, PW TI Numerical heating in hybrid plasma simulations SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article ID PARTICLE AB The numerical heating in hybrid particle-fluid simulations has been investigated with emphasis on the regime ZT(e)/T-i much greater than 1, where Z is the charge state of the ions and T-e and T-i are the electron and ion temperatures, respectively. For the simple case of particle ions advanced in the ambipolar field due to quasineutral isothermal fluid electrons, the heating rate is observed to be weakly dependent on time step, inversely proportional to the number of simulation particles per grid cell and strongly increasing with increasing ZT(e)/T-i. Additional smoothing, due to finite Debye length, or introduced through numerical means such as higher order particle interpolation or smoothing of grid quantities, is observed to significantly reduce this heating. Both one- and two-dimensional results are presented. These results are important to hybrid particle simulations of laser generated plasmas, a regime where ZT(e)/T-i much greater than 1 is often encountered. As a relevant example, simulations of stimulated Brillouin scattering are presented illustrating the deleterious effect of numerical heating and attendant distortions to the particle distribution function. (C) 1997 Academic Press. RP Rambo, PW (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 808,LIVERMORE,CA 94550, USA. NR 15 TC 4 Z9 4 U1 1 U2 8 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 MAY 1 PY 1997 VL 133 IS 1 BP 173 EP 180 DI 10.1006/jcph.1997.5678 PG 8 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA WX892 UT WOS:A1997WX89200014 ER PT J AU Zhang, YH Lew, A Yu, E Chen, Y AF Zhang, YH Lew, A Yu, E Chen, Y TI Microstructural properties of InAs/InAsxSb1-x superlattices and InAsxSb1-x ordered alloys grown by modulated molecular beam epitaxy SO JOURNAL OF CRYSTAL GROWTH LA English DT Article; Proceedings Paper CT 9th International Conference on Molecular Beam Epitaxy (MBE-IX) CY AUG 05-09, 1996 CL PEPPERDINE UNIV, MALIBU, CA HO PEPPERDINE UNIV DE MBE; InAs; InAsSb; InSb; STM; TEM ID INASSB AB Modulated molecular beam epitaxy (MMBE) has been demonstrated to be useful in controlling group-V alloys such as InAsxSb1-x and AlAsxSb1-x. Further studies of the MMBE grown InAsxSb1-x ordered alloys and InAs/InAsxSb1-x superlattices by using cross-sectional scanning tunneling microscopy show well defined interfaces between InAsxSb1-x ordered alloys and InAs. Clear composition modulation is observed in the InAsxSb1-x ordered alloy layers. Transmission electron diffraction and microscopy, X-ray diffraction, and low temperature photoluminescence experiments show no obvious sign of CuPt orderings. These results suggest that MMBE provides a possible means to bypass the ordering problem of InAsxSb1-x random alloys. C1 UNIV CALIF SAN DIEGO,DEPT ELECT ENGN & COMP SCI,LA JOLLA,CA 92093. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. ARIZONA STATE UNIV,DEPT ELECT ENGN,TEMPE,AZ 85287. RP Zhang, YH (reprint author), HUGHES RES LABS,3011 MALIBU CANYON RD,MALIBU,CA 90265, USA. RI Yu, Edward/A-3515-2017 OI Yu, Edward/0000-0001-9900-7322 NR 11 TC 3 Z9 3 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-0248 J9 J CRYST GROWTH JI J. Cryst. Growth PD MAY PY 1997 VL 175 BP 833 EP 837 DI 10.1016/S0022-0248(96)01201-8 PN 2 PG 5 WC Crystallography; Materials Science, Multidisciplinary; Physics, Applied SC Crystallography; Materials Science; Physics GA XX179 UT WOS:A1997XX17900026 ER PT J AU Jasinski, J LilientalWeber, Z Washburn, J Tan, HH Jagadish, C Krotkus, A Marcinkevicius, S Kaminska, M AF Jasinski, J LilientalWeber, Z Washburn, J Tan, HH Jagadish, C Krotkus, A Marcinkevicius, S Kaminska, M TI Structural, electrical, and optical studies of GaAs implanted with MeV As or Ga ions SO JOURNAL OF ELECTRONIC MATERIALS LA English DT Article DE GaAs; ion implantation; point defects ID MOLECULAR-BEAM EPITAXY; PICOSECOND CARRIER LIFETIME; TEMPERATURE-GROWN GAAS; LAYERS AB The structural properties of GaAs implanted with high doses of 2 MeV arsenic or gallium ions with subsequent annealing at different temperatures were studied by transmission electron microscopy, Rutherford backscattering spectrometry-channeling, double crystal x-ray diffraction. Optical absorption, electrical conductivity, Hall effect and time-resolved photoluminescence were applied to monitor changes in electrical and optical characteristics of the material. An important conclusion from this investigation is that there was hardly any difference between materials implanted with gallium or arsenic. For implantation of either species, a large number of point defects was introduced and for a high enough dose a buried amorphous layer was formed. Hopping conduction and high absorption below band-to-band transition were observed for both cases. After low temperature annealing of the amorphous material, a high density of stacking faults and microtwins were found. Regrowth rates at the front and back amorphous-crystalline interfaces showed a significant difference. This was attributed to differences in local nonstoichiometry of the material at the upper and lower amorphous-crystalline interfaces. Structural studies showed the presence of some residual damage (a band of polycrystalline material in the center of the regrown area) with some associated strain even after annealing at high temperatures. Recovery to the conduction band transport in annealed samples was observed but mobilities, of the order of 2000 cm(2)/Vs, were still smaller than in unimplanted GaAs. These results show that, in as-implanted material and even after annealing at lower temperatures, the point defects introduced by the implantation are responsible for the very short photocarrier lifetime. C1 AUSTRALIAN NATL UNIV,RES SCH PHYS SCI & ENGN,DEPT ELECT MAT ENGN,CANBERRA,ACT 0200,AUSTRALIA. INST SEMICOND PHYS,LT-2600 VILNIUS,LITHUANIA. UNIV WARSAW,INST EXPT PHYS,PL-00681 WARSAW,POLAND. ROYAL INST TECHNOL,DEPT PHYS 2,S-10044 STOCKHOLM,SWEDEN. RP Jasinski, J (reprint author), UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720, USA. RI Liliental-Weber, Zuzanna/H-8006-2012; Tan, Hark Hoe/M-1148-2015 OI Tan, Hark Hoe/0000-0002-7816-537X NR 35 TC 8 Z9 8 U1 3 U2 11 PU MINERALS METALS MATERIALS SOC PI WARRENDALE PA 420 COMMONWEALTH DR, WARRENDALE, PA 15086 SN 0361-5235 J9 J ELECTRON MATER JI J. Electron. Mater. PD MAY PY 1997 VL 26 IS 5 BP 449 EP 458 DI 10.1007/s11664-997-0118-4 PG 10 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Physics, Applied SC Engineering; Materials Science; Physics GA WY101 UT WOS:A1997WY10100007 ER PT J AU Cantrell, KJ Kaplan, DI AF Cantrell, KJ Kaplan, DI TI Zero-valent iron colloid emplacement in sand columns SO JOURNAL OF ENVIRONMENTAL ENGINEERING-ASCE LA English DT Article ID GROUNDWATER; METALS AB Studies were conducted to evaluate a novel approach of emplacing chemically reactive barriers composed of zero-valent iron (Fe-0) by injecting suspensions of colloidal-size Fe-0 particles into porous media. The specific objective of this study was to evaluate the effect of influent colloid concentration, rate, and volume of colloidal suspensions on Fe-0 colloid emplacement in sand columns. Relatively even distributions of Fe-0 throughout a sand column were obtained at low influent colloid concentrations and high injection rates. As the concentration of influent suspension was increased, a point was reached beyond which a significant increase in the filtration of Fe-0 particles near the front of the column was observed. This point was also found to occur at lower influent colloid concentrations as the injection rate was decreased, i.e., there was an interactive effect of influent colloid concentration and injection rate on the extent of filtration that occurred near the front of the column. As the volume of the colloidal suspension injected into the column was increased, the distribution of Fe-0 colloids within the column became increasingly even. RP Cantrell, KJ (reprint author), PACIFIC NW LAB, POB 999,MAILSTOP K6-81, RICHLAND, WA 99352 USA. NR 32 TC 28 Z9 28 U1 1 U2 2 PU ASCE-AMER SOC CIVIL ENGINEERS PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9372 J9 J ENVIRON ENG-ASCE JI J. Environ. Eng.-ASCE PD MAY PY 1997 VL 123 IS 5 BP 499 EP 505 DI 10.1061/(ASCE)0733-9372(1997)123:5(499) PG 7 WC Engineering, Environmental; Engineering, Civil; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA WV733 UT WOS:A1997WV73300014 ER PT J AU Dudka, S Adriano, DC AF Dudka, S Adriano, DC TI Environmental impacts of metal ore mining and processing: A review SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Review ID COPPER SMELTER; POLLUTED SOILS; UPPER SILESIA; TRACE-METALS; SUDBURY; CONTAMINATION; ONTARIO; POLAND; ZINC; VEGETATION AB The impact of mining and smelting of metal ores on environmental quality is described. Mines produce large amounts of waste because the ore is only a small fraction of the total volume of the mined material. In the metal industry, production of Cu, Pb, and Zn causes the greatest degradation of the environment. Copper mining produces extensive mine wastes and tailings and Cu smelting emits approximately 0.11 Mg of S per Mg of Cu produced in the USA. Zinc and ph smelters release large quantities of Cd and Pb into the environment. Metal smelting and refining produce gaseous (CO2, SO2, NOx, etc.) and particulate matter emissions, sewage waters, and solid wastes. Soil contamination with trace metals is considered a serious problem related to smelting; however, mining and smelting are not main sources of global metal input into soils. Other sources like discarded manufactured products, coal ash, agriculture, and transportation take a lead. Smelters are the main sources of atmospheric emissions of As, Cu, Cd, Sb, and Zn on a global scale and they contribute substantially to the overall emissions of Cr, Pb, Se, and Ni. A quantitative evaluation of the environmental health effects of mining and smelting is difficult because of the complexity of factors involved and lack of consistent methodology. Nevertheless, the case studies described indicate that negative health effects could arise from Pb mining and smelting. Risk assessment revealed that food chain contamination by Cd from soils contaminated by smelting is very unlikely under the western diet. C1 UNIV GEORGIA, SAVANNAH RIVER ECOL LAB, DIV BIOGEOCHEM ECOL, AIKEN, SC 29802 USA. RP Dudka, S (reprint author), UNIV GEORGIA, DEPT CROP & SOIL SCI, 3111 MILLER PLANT SCI BLDG, ATHENS, GA 30602 USA. NR 101 TC 227 Z9 266 U1 26 U2 208 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 USA SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAY-JUN PY 1997 VL 26 IS 3 BP 590 EP 602 PG 13 WC Environmental Sciences SC Environmental Sciences & Ecology GA WZ349 UT WOS:A1997WZ34900010 ER PT J AU Ward, AL Gee, GW AF Ward, AL Gee, GW TI Performance evaluation of a field-scale surface barrier SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article AB Surface barriers, designed to limit recharge and biointrusion, have been identified as a critical component in long-term management of buried wastes. However, surface barrier technology remains largely unproven at the field scale. Recently, a prototype of a field-scale (2.5 ha), vegetated, capillary surface barrier was constructed over a waste zone at the semiarid Hanford Site in southeast Washington. The barrier is instrumented to measure the components of water balance under ambient and elevated precipitation scenarios on soil and rock-covered plots. The barrier also allows for the evaluation of two protective side slope configurations, and the monitoring of flow around and under a low permeability asphalt layer. The first 2 yr of testing were unusually wet, with precipitation more than twice the long-term annual average of 160 mm. Even with an imposed irrigation treatment of 480 mm yr(-1), including a simulated 1000-yr storm event each year, there was no drainage from the soil covered plots. This demonstrates the effectiveness of vegetated capillary barriers in an arid environment. Each year, plants used all available water, independent of precipitation treatment, reducing soil water storage to the same lower limit by the end of summer. The soil was wettest during spring, but water storage never exceeded 450 mm in the 2-m thick soil layer, which was designed to store 600 mm. The efficiency of ET was consistently higher on the ambient treatment, suggesting a susceptibility of native plant species to high levels of precipitation. No water has penetrated the low-permeability asphalt layer, although an unprotected section of the toe showed a potential for underflow. While there was no difference in total drainage from the irrigated side slopes over the last 2 yr, the nonirrigated basalt slope drained 55% less water than the gravel. Side slope drainage also showed a seasonal dependence, with the gravel draining more than the basalt in winter and less in the summer. Drainage rates and volumes appear to be controlled by advective airflow. RP Ward, AL (reprint author), PACIFIC NW LAB, DEP WATER & LAND RESOURCES, POB 999,K9-33, RICHLAND, WA 99352 USA. NR 18 TC 31 Z9 31 U1 0 U2 3 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAY-JUN PY 1997 VL 26 IS 3 BP 694 EP 705 PG 12 WC Environmental Sciences SC Environmental Sciences & Ecology GA WZ349 UT WOS:A1997WZ34900022 ER PT J AU Hesse, M Birn, J Hoffman, RA AF Hesse, M Birn, J Hoffman, RA TI On the mapping of ionospheric convection into the magnetosphere SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID GENERAL MAGNETIC RECONNECTION; DEPENDENT PLASMA-FLOW; DAYSIDE MAGNETOSPHERE; BIRKELAND CURRENTS; GEOMAGNETIC TAIL; ELECTRIC-FIELDS; PRECIPITATION; CONDUCTIVITY; MODEL; IMF AB Under steady state conditions and in the absence of parallel electric fields, ionospheric convection is a direct map of plasma and magnetic flux convection in the magnetosphere, and quantitative estimates can be obtained from the mapping along magnetic field lines of electrostatic ionospheric electric fields. The resulting magnetospheric electrostatic potential distribution then provides the convection electric field in various magnetospheric regions. We present a quantitative framework for the investigation of the applicability and limitations of this approach based on an analytical theory derived from first principles. Particular emphasis is on the role of parallel electric field regions and on inductive effects, such as expected during the growth and expansive phases of magnetospheric substorms. We derive quantitative estimates for the limits in which either effect leads to a significant decoupling between ionospheric and magnetospheric convection and provide an interpretation of ionospheric convection which is independent of the presence of inductive electric fields elsewhere in the magnetosphere. Finally, we present a study of the relation between average and instantaneous convection, using two periodic dynamical models. The models demonstrate and quantify the potential mismatch between the average electric fields in the ionosphere and the magnetosphere in strongly time-dependent cases that may exist even when they are governed entirely by ideal MHD. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87544. RP Hesse, M (reprint author), NASA,GODDARD SPACE FLIGHT CTR,ELECTRODYNAM BRANCH,CODE 696,GREENBELT,MD 20771, USA. RI Hesse, Michael/D-2031-2012 NR 36 TC 19 Z9 19 U1 0 U2 2 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 MAY 1 PY 1997 VL 102 IS A5 BP 9543 EP 9551 DI 10.1029/96JA03999 PG 9 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WX560 UT WOS:A1997WX56000004 ER PT J AU Maynard, NC Burke, WJ Erickson, GM Nakamura, M Mukai, T Kokubun, S Yamamoto, T Jacobsen, B Egeland, A Samson, JC Weimer, DR Reeves, GD Luhr, H AF Maynard, NC Burke, WJ Erickson, GM Nakamura, M Mukai, T Kokubun, S Yamamoto, T Jacobsen, B Egeland, A Samson, JC Weimer, DR Reeves, GD Luhr, H TI Geotail measurements compared with the motions of high-latitude auroral boundaries during two substorms SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID TRAVELING COMPRESSION REGIONS; LOW-ENERGY PARTICLE; EARTHS MAGNETOTAIL; MAGNETOSPHERIC SUBSTORMS; PLASMA SHEET; DISTANT TAIL; SATELLITE; R(E); MAGNETOMETER; CONVECTION AB Geotail plasma and field measurements at -95 R-E are compared with extensive ground-based, near-Earth, and geosynchronous measurements to study relationships between amoral activity and magnetotail dynamics during the expansion phases of two substorms, The studied intervals are representative of intermittent, moderate activity, The behavior of the aurora and the observed effects at Geotail for both events are harmonized by the concept of the activation of near-Earth X lines (NEXL) after substorm onsets with subsequent discharges of one or more plasmoids down the magnetotail, The plasmoids must be viewed as three-dimensional structures which are spatially limited in the dawn-dusk direction. Also, reconnection at the NEXL must proceed at variable rates on closed magnetic field lines for significant times before beginning to reconnect lobe flux, This implies that the plasma sheet in the near-Earth magnetotail is relatively thick in comparison with an embedded current sheet and that both the NEXL and distant X line can be active simultaneously, Until reconnection at the NEXL engages lobe flux, the distant X line maintains control of the poleward auroral boundary. if the NEXL remains active after reaching the lobe, the amoral boundary can move poleward explosively, The dynamics of high-latitude aurora in the midnight region thus provides a means for monitoring these processes and indicating when significant lobe flux reconnects at the NEXL. C1 PHILIPS LABS,HANSCOM AFB,MA 01731. UNIV OSLO,DEPT PHYS,N-0316 OSLO,NORWAY. BOSTON UNIV,CTR SPACE PHYS,BOSTON,MA 02215. NAGOYA UNIV,SOLAR TERR ENVIRONM LAB,TOYOKAWA 441,JAPAN. INST SPACE & ASTRONAUT SCI,SAGAMIHARA,KANAGAWA 229,JAPAN. UNIV TOKYO,DEPT EARTH & PLANETARY PHYS,TOKYO 113,JAPAN. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. UNIV ALBERTA,DEPT PHYS,CANADIAN NETWORK SPACE RES,EDMONTON,AB T6G 2J1,CANADA. INST SPACE & ASTRONAUT SCI,KANAGAWA 229,JAPAN. TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST GEOPHYS & METEOROL,D-3300 BRAUNSCHWEIG,GERMANY. RP Maynard, NC (reprint author), MISSION RES CORP,1 TARA BLVD,SUITE 302,NASHUA,NH 03062, USA. RI Reeves, Geoffrey/E-8101-2011 OI Reeves, Geoffrey/0000-0002-7985-8098 NR 50 TC 12 Z9 12 U1 0 U2 4 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 MAY 1 PY 1997 VL 102 IS A5 BP 9553 EP 9572 DI 10.1029/97JA00307 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WX560 UT WOS:A1997WX56000005 ER PT J AU Liewer, PC Brackbill, JU AF Liewer, PC Brackbill, JU TI Hydrodynamic instability of the heliopause driven by plasma-neutral charge-exchange interactions - Reply SO JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS LA English DT Article ID LOCAL INTERSTELLAR-MEDIUM; SOLAR-WIND C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Liewer, PC (reprint author), CALTECH,JET PROP LAB,MS 169-506,PASADENA,CA 91109, USA. NR 8 TC 5 Z9 5 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 MAY 1 PY 1997 VL 102 IS A5 BP 9839 EP 9842 DI 10.1029/97JA00153 PG 4 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA WX560 UT WOS:A1997WX56000035 ER PT J AU Schaub, H Junkins, JL Robinett, RD AF Schaub, H Junkins, JL Robinett, RD TI New penalty functions and optimal control formulation for spacecraft attitude control problems SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article ID REPRESENTATIONS AB A universal attitude penalty function g() is presented that renders spacecraft optimal control problem solutions independent of attitude coordinate choices, This function returns the same scalar penalty for a given physical attitude regardless of the choice of attitude coordinates used to describe this attitude, The only singularities the g() function might encounter are solely due to the choice of attitude coordinates. A second attitude penalty function G() is considered, which depends specifically on the modified Rodrigues parameter (MRP) vector sigma. The MRPs allow for a nonsingular attitude description through a noncontinuous switch to their associated shadow set, A corresponding switching condition is presented for the MRP costates to allow the nonsingular MRP attitude description to be used in optimal control problems, Computational experiments are used to illustrate and validate the analytical results. C1 SANDIA NATL LABS,ALBUQUERQUE,NM 87185. RP Schaub, H (reprint author), TEXAS A&M UNIV,DEPT AEROSP ENGN,COLLEGE STN,TX 77843, USA. NR 13 TC 21 Z9 22 U1 0 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1997 VL 20 IS 3 BP 428 EP 434 DI 10.2514/2.4093 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA WY344 UT WOS:A1997WY34400004 ER PT J AU Kim, TJ Hull, DG AF Kim, TJ Hull, DG TI Neighboring extremal control design using error compensation SO JOURNAL OF GUIDANCE CONTROL AND DYNAMICS LA English DT Article; Proceedings Paper CT AIAA Guidance, Navigation, and Control Conference CY AUG 07-10, 1995 CL BALTIMORE, MD SP AIAA ID GUIDANCE LAW AB Error compensation, which has been used to improve the performance of approximate analytical optimal controls, is extended to neighboring extremal control, The optimal control problem with error compensation is defined, the first variation conditions are linearized about an optimal path to account for perturbations in the initial state and the final constraint manifold, and the neighboring extremal control is derived, A vehicle guidance example demonstrates that the tuning procedure inherent in error compensation moves the performance of the derived control toward that of a numerically determined piecewise linear optimal control. C1 UNIV TEXAS,DEPT AEROSP ENGN & ENGN MECH,AUSTIN,TX 78712. RP Kim, TJ (reprint author), SANDIA NATL LABS,AIDED NAVIGAT & REMOTE SENSING DEPT,TECH STAFF,ALBUQUERQUE,NM 87106, USA. NR 11 TC 1 Z9 1 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0731-5090 J9 J GUID CONTROL DYNAM JI J. Guid. Control Dyn. PD MAY-JUN PY 1997 VL 20 IS 3 BP 542 EP 548 DI 10.2514/2.4075 PG 7 WC Engineering, Aerospace; Instruments & Instrumentation SC Engineering; Instruments & Instrumentation GA WY344 UT WOS:A1997WY34400020 ER PT J AU Thompson, B Montano, DE Mahloch, J Mullen, M Taylor, V AF Thompson, B Montano, DE Mahloch, J Mullen, M Taylor, V TI Attitudes and beliefs toward mammography among women using an urban public hospital SO JOURNAL OF HEALTH CARE FOR THE POOR AND UNDERSERVED LA English DT Article DE mammography; elicitation interviews; focus groups; low-income women; qualitative methods ID BREAST-CANCER; RACIAL-DIFFERENCES; MORTALITY AB Although overall use of mammography is steadily increasing, few-income and majority women consistently have relatively lower screening rates than white, middle-class women. To assess the mammography-seeking behavior of low-income women using an urban public hospital, this study sought to understand why women in this population decide whether or not to obtain a screening mammogram. Two qualitative techniques, elicitation interviews and focus groups, were used to develop an understanding of attitudes, concerns, and barriers of this group relative to mammography. Fear, embarrassment, susceptibility to breast cancer, inconvenience, cast, concerns about efficacy of mammography, fear of acquiring cancer, and scheduling difficulties were identified as important concerns. ''People in the news'' were the most influential social referents for mammography decision: making,followed by physicians, family members, and friends; The insights gained from these women will assist in developing interventions that encourage mammography-seeking behavior by few-income women. C1 BATELLE SEATTLE RES CTR,SEATTLE,WA 98105. HARBORVIEW MED CTR,SEATTLE,WA 98104. RP Thompson, B (reprint author), FRED HUTCHINSON CANC RES CTR,1124 COLUMBIA,MP-702,SEATTLE,WA 98104, USA. FU NCI NIH HHS [CA62119] NR 27 TC 33 Z9 33 U1 1 U2 1 PU SAGE PUBLICATIONS INC PI THOUSAND OAKS PA 2455 TELLER RD, THOUSAND OAKS, CA 91320 SN 1049-2089 J9 J HEALTH CARE POOR U JI J. Health Care Poor Underserved PD MAY PY 1997 VL 8 IS 2 BP 186 EP 201 PG 16 WC Health Policy & Services; Public, Environmental & Occupational Health SC Health Care Sciences & Services; Public, Environmental & Occupational Health GA WT779 UT WOS:A1997WT77900005 PM 9114627 ER PT J AU Gritzo, LA Tieszen, SR Murray, D AF Gritzo, LA Tieszen, SR Murray, D TI Flame structure of large, hydrocarbon-fueled pool fires SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT International Mechanical Engineering Congress and Exposition - Winter Annual Meeting of the ASME CY NOV 17-22, 1996 CL ATLANTA, GA SP Amer Soc Mech Engineers C1 USN,AIR WARFARE CTR,WEAPONS DIV,CHINA LAKE,CA. RP Gritzo, LA (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 209 EP 209 DI 10.1115/1.2824210 PG 1 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA XB119 UT WOS:A1997XB11900011 ER PT J AU Parlatan, Y Rohatgi, US AF Parlatan, Y Rohatgi, US TI Simple model of boiling heat transfer on tubes in large pools SO JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME LA English DT Article DE boiling; heat exchangers; natural convection ID VERTICAL SURFACE AB A simple method has been developed to model boiling heat transfer from a heat exchanger to pools using the experimental data available in the literature without modeling the flow dynamics of the pool. In this approach the heat flux outside vertical tubes is expressed as a function of outside wall temperature of the tubes and saturation temperature of the pool at or near atmospheric pressure. C1 BROOKHAVEN NATL LAB,DEPT ADV TECHNOL,UPTON,NY 11973. RP Parlatan, Y (reprint author), ATOM ENERGY CANADA LTD,MISSISSAUGA,ON L5K 1B2,CANADA. NR 11 TC 2 Z9 2 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0022-1481 J9 J HEAT TRANS-T ASME JI J. Heat Transf.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 376 EP 379 DI 10.1115/1.2824237 PG 4 WC Thermodynamics; Engineering, Mechanical SC Thermodynamics; Engineering GA XB119 UT WOS:A1997XB11900036 ER PT J AU Thakur, ML Li, J Donegan, M Pallela, VR Kolan, H Duggaraju, R Maish, D Srivastava, S AF Thakur, ML Li, J Donegan, M Pallela, VR Kolan, H Duggaraju, R Maish, D Srivastava, S TI Improved antibody targeting with interferon-alpha-2b conjugate SO JOURNAL OF IMMUNOTHERAPY LA English DT Article DE biological response modifiers; tumor uptake of Tc-99m mAb, improving; immunoconjugate; interferon-alpha-2b; Tc-99m-mAb ID RECOMBINANT ALPHA-INTERFERON; BIOLOGICAL RESPONSE MODIFIERS; MONOCLONAL-ANTIBODY; GAMMA-INTERFERON; TUMOR XENOGRAFT; BLOOD-FLOW; ENHANCEMENT; THERAPY; CANCER; RADIOIMMUNOTHERAPY AB This investigation is based on a hypothesis that a biological response modifier, interferon-alpha-2b (IFN), when conjugated with a specific monoclonal antibody (mAb) and given to tumor-bearing animals before the administration of radiolabeled mBb, may not only augment the tumor uptake but may also impede the liver and blood uptake, because the mAb associated with the conjugate may block nonspecific hepatic binding sites and scavenge circulating antigens. ME 31.3 and anti-carcinoembryonic antigen (CEA) F-6 (IgG-2a) specific for human melanoma and colorectal carcinoma, respectively, were chosen as prototype mAbs and conjugated with IFN-alpha-2b for evaluation in athymic nude mice bearing respective experimental tumors. The mAb specificity for the tumor cell line was examined by binding assays and Kd values were determined to be 1.96 x 10(-9) M and 5.9 x 10(-9) M for ME 31.3 and anti-CEA F-6, respectively. Thirty micrograms of conjugate, prepared chemically and purified chromatographically (IFN-mAb:1:1), was administered intravenously to each animal and 3 h later followed by an intravenous injection of 20 mu g F(ab')(2) of corresponding mAb labeled with 300 mu Ci Tc-99m (1.5 Ci/mmol). Twenty-four hours later, in melanoma-bearing animals, not only did the tumor uptake increase, but also the liver uptake decreased by 75%. Tumor/muscle and tumor/blood ratios also enhanced by 200 and 500%, respectively. Consistent with ME 31.3, the tumor uptake with anti-CEA F-6 also increased (p = 0.00) and the liver uptake decreased (p = 0.01). Similarly, tumor/muscle (p = 0.01) and tumor/blood (p = 0.02) ratios also increased significantly. Results indicate that IFN:mAb conjugate may improve diagnostic and therapeutic potential of mAbs, and is worthy of further studies. C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. RP Thakur, ML (reprint author), THOMAS JEFFERSON UNIV HOSP,DEPT RADIOL,DIV NUCL MED,1020 LOCUST ST,SUITE 359,PHILADELPHIA,PA 19107, USA. NR 46 TC 5 Z9 5 U1 0 U2 1 PU LIPPINCOTT-RAVEN PUBL PI PHILADELPHIA PA 227 EAST WASHINGTON SQ, PHILADELPHIA, PA 19106 SN 1053-8550 J9 J IMMUNOTHER JI J. Immunother. PD MAY PY 1997 VL 20 IS 3 BP 194 EP 201 DI 10.1097/00002371-199705000-00004 PG 8 WC Oncology; Immunology; Medicine, Research & Experimental SC Oncology; Immunology; Research & Experimental Medicine GA XA886 UT WOS:A1997XA88600004 PM 9181457 ER PT J AU Page, RH Schaffers, KI Payne, SA Krupke, WF AF Page, RH Schaffers, KI Payne, SA Krupke, WF TI Dy-doped chlorides as gain media for 1.3 mu m telecommunications amplifiers SO JOURNAL OF LIGHTWAVE TECHNOLOGY LA English DT Article DE dysprosium materials/devices; lasers; optical amplifiers; optical materials; solid lasers ID FLUORIDE FIBER AMPLIFIER; PHONON-ENERGY GLASSES; OPTICAL AMPLIFIERS; 1.3-MU-M AMPLIFICATION AB We propose that Dy3+-doped chloride crystals be considered as candidates for amplification of the 1.3 mu m signal used by the telecommunications network. While several of these types of crystals can provide gain at the specified operating wavelength of 1.31 mu m, and furthermore offer adequate bandwidth, we have focused our attention on LaCl3:Dy as an illustrative case to explore in greater depth. Spectroscopic measurements were made on un-oriented samples of this material; excited-state lifetimes and LaCl3:Dy3+ Judd-Ofelt parameters are reported. Wavelength-resolved absorption and emission cross sections are presented for the 1.3 mu m W <----> Z band. Pump-probe measurements (using 0.92 mu m and 1.32 mu m, respectively) prove that the observed gain properties of LaCl3:Dy are consistent with those predicted on the basis of the spectroscopic cross sections, The Dy:chloride gain media appear to have fundamental optical characteristics amenable to superior 1.3 mu m telecom amplifier performance, although many fabrication issues would have to be addressed to produce a practical amplifier. RP Page, RH (reprint author), LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550, USA. NR 49 TC 32 Z9 32 U1 0 U2 3 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0733-8724 J9 J LIGHTWAVE TECHNOL JI J. Lightwave Technol. PD MAY PY 1997 VL 15 IS 5 BP 786 EP 793 DI 10.1109/50.580816 PG 8 WC Engineering, Electrical & Electronic; Optics; Telecommunications SC Engineering; Optics; Telecommunications GA WX890 UT WOS:A1997WX89000008 ER PT J AU Clements, BE Krotscheck, E Tymczak, CJ AF Clements, BE Krotscheck, E Tymczak, CJ TI Thermal properties of He-4 surfaces and interfaces SO JOURNAL OF LOW TEMPERATURE PHYSICS LA English DT Article ID BOSON QUANTUM FILMS; NONZERO TEMPERATURES; HELIUM; LIQUID-HE-4; FLUIDS AB A first-principle quantum statistical mechanical theory is used to study the properties of thick liquid He-4 films absorbed to the weakly binding substr ates: Li, Na, and Cs. Values for the liquid-gas and solid-liquid surface energies are determined By fitting, at long wavelengths, the film's lowest energy mode with the standard expression for the ripplon energy, which depends on the liquid-gas surface energy, we obtain excellent agreement with rite liquid-vacuum surface energy from recent experiments and also the one previously extracted from quantum liquid droplet calculations. The full spectrum of excitations for wave vectors less than 0.50 Angstrom(-1) is calculated using a dynamical correlated basis function theory developed in earlier work, which includes multi-phonon scattering processes. Particle currents and transition densities are used to elucidate the nature of the excitations. At a coverage of 0.40 Angstrom(-2). the lowest mode shows no significant substrate dependence, and is recognized as being a ripplon propagating in the liquid film at the liquid-gas surface. A new effect is observed for the Cs substrate; rite second lowest mode is qualitatively different than found on the other substrates and is identified as interfacial ripplon. In the other substrates the second mode is a volume mode altered somewhat by the high density inner liquid layers. The linewidths of these modes are also calculated. The dynamic excitations provide the input for the thermodynamic theory and the effects on the free energy, heat capacity, and thermal surface broadening of our films are studied as function of the nature of the excitations, the number of modes, and variations in the substrate potentials. C1 JOHANNES KEPLER UNIV,INST THEORET PHYS,A-4040 LINZ,AUSTRIA. TEXAS A&M UNIV,DEPT PHYS,COLLEGE STN,TX 77843. CLARK ATLANTA UNIV,DEPT PHYS,ATLANTA,GA 30314. RP Clements, BE (reprint author), LOS ALAMOS NATL LAB,DIV THEORET,LOS ALAMOS,NM 87545, USA. NR 32 TC 12 Z9 12 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 SN 0022-2291 J9 J LOW TEMP PHYS JI J. Low Temp. Phys. PD MAY PY 1997 VL 107 IS 3-4 BP 387 EP 419 DI 10.1007/BF02397465 PG 33 WC Physics, Applied; Physics, Condensed Matter SC Physics GA WW762 UT WOS:A1997WW76200010 ER PT J AU Sugg, DW Chesser, RK Long, JC AF Sugg, DW Chesser, RK Long, JC TI Assessment of genetic information in morphometric traits: Geographic patterns and evolutionary interpretation SO JOURNAL OF MAMMALOGY LA English DT Article DE Peromyscus; geographic patterns; heritability; morphometric traits; variance partitioning ID QUANTITATIVE CHARACTERS; MORPHOLOGICAL VARIATION; ENZYME HETEROZYGOSITY; PEROMYSCUS-ATTWATERI; TEXAS MOUSE; POPULATIONS; HERITABILITY; VARIANCE; DRIFT; SIZES AB Comparative studies often indicate a lack of concordant geographic patterns for morphometric and genic traits. Herein, it is shown that the genetic variance of morphometric traits can be partitioned into within- and among-group components as is traditionally done with genic data. Employing these methods demonstrates that there is considerable congruence for estimates of differentiation from genic and morphometric data for populations of the Texas mouse, Peromyscus attwateri. Within-group genetic variances of morphometric traits, relative to that of genic traits, also can be estimated. From these estimates, a pseudo-heritability can be obtained. Pseudo-heritabilities generally are low, indicating that evolutionary forces have removed much of the genetic variation within groups, or that environmental variation is considerable for morphometric traits. The combined use of genic and morphometric traits offer greater insight into past evolution that has lead to geographic patterns. C1 UNIV GEORGIA,SAVANNAH RIVER ECOL LAB,AIKEN,SC 29809. UNIV GEORGIA,DEPT GENET,ATHENS,GA 30602. NIH,NEUROGENET LAB,ROCKVILLE,MD 20852. NR 44 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD MAY PY 1997 VL 78 IS 2 BP 405 EP 416 DI 10.2307/1382894 PG 12 WC Zoology SC Zoology GA XB316 UT WOS:A1997XB31600014 ER PT J AU McLuckey, SA Goeringer, DE AF McLuckey, SA Goeringer, DE TI Slow heating methods in tandem mass spectrometry SO JOURNAL OF MASS SPECTROMETRY LA English DT Review DE tandem mass spectrometry; slow heating methods; collisional activation; multiphoton dissociation; ion cyclotron resonance; quadrupole ion trap ID COLLISION-INDUCED DISSOCIATION; INFRARED MULTIPHOTON DISSOCIATION; QUADRUPOLE ION-TRAP; MULTIPLY-CHARGED IONS; CYCLOTRON RESONANCE SPECTROMETRY; SMALL CLUSTER IONS; POLYATOMIC IONS; UNIMOLECULAR DISSOCIATION; LOW-ENERGY; PHOTON DISSOCIATION AB Several approaches to ion activation in tandem mass spectrometry have been developed in recent years for use in ion trapping instruments that allow for conditions to be reached wherein rates of ion activation and deactivation are comparable. These approaches are defined as slow heating methods and include continuous-wave laser infrared multiphoton dissociation, dissociation driven by blackbody radiation, quadropole ion trap collisional activation and sustained off-resonance irradiation in ion cyclotron resonance mass spectrometry. In the Limiting case in which ion activation and deactivation rates are equal, a steady-state parent ion internal energy distribution is achieved and the kinetics of dissociation can be interpreted in analogy with thermal dissociation. This discussion describes the thermal analogy and the Limiting conditions of rapid energy exchange and slow energy exchange along with the possible ramifications for dissociation rates and product ion spectra, The figures of merit that the various slow heating methods share as a class of activation methods are also discussed. The purpose of this perspective is to provide a frame-of-reference from which slow heating methods can be considered. Such methods are seeing increasing nse as the number of ion trapping instruments grows and have shown remarkable success with dissociation of high-mass ions. (C) 1997 by John Wiley & Sons, Ltd. RP OAK RIDGE NATL LAB, DIV CHEM & ANALYT SCI, OAK RIDGE, TN 37831 USA. RI McLuckey, Scott/B-2203-2009 OI McLuckey, Scott/0000-0002-1648-5570 NR 113 TC 265 Z9 266 U1 3 U2 43 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 1076-5174 EI 1096-9888 J9 J MASS SPECTROM JI J. Mass Spectrom. PD MAY PY 1997 VL 32 IS 5 BP 461 EP 474 PG 14 WC Biochemical Research Methods; Chemistry, Analytical; Spectroscopy SC Biochemistry & Molecular Biology; Chemistry; Spectroscopy GA WZ316 UT WOS:A1997WZ31600001 ER PT J AU Wu, KT Fischer, AK Maroni, VA Rupich, MW AF Wu, KT Fischer, AK Maroni, VA Rupich, MW TI Raman microscopy examination of phase evolution in Bi(Pb)-Sr-Ca-Cu-O superconducting ceramics SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CU-O SYSTEM; COMPOSITE CONDUCTORS; PB; TEMPERATURE; LEAD; BISMUTH-2223; BI,PB(2212); ALIGNMENT; SPECTRA; CAO AB Raman microspectroscopy (RMS) and imaging Raman microscopy (IRM) were used to probe the composition and spatial distribution of chemical phases in Bi(Pb)-Sr-Ca-Cu-O (BSCCO) ceramic superconductor powders and silver-BSCCO composites. The Raman techniques were used to identify various phases, including alkaline earth cuprates, CuO, Bi-2212, Bi-2223, and Pb-containing phases. Changes in the Ca/Sr ratios in (Ca, Sr)(2)CuO3 phases were distinguished by differences in orientation with respect to polarization of the exciting radiation. Variations were observed in the content and distribution of lead in various phases formed during intermediate stages of the thermal processing of composite conductors. The spatial distribution of the various phases detected in powder and composite conductors was established to a resolution of a few microns by collecting images of the Raman scattering at wavelengths corresponding to the signature peaks of the observed phases. Reference Raman spectra of the major phases observed in the BSCCO system are also reported. The Raman techniques, when combined with complementary techniques, such as x-ray diffraction and electron microscopy, can provide valuable information about the reaction paths and mechanisms of the high temperature BSCCO superconducting ceramics. C1 ARGONNE NATL LAB,ARGONNE,IL 60439. AMER SUPERCONDUCTOR CORP,WESTBOROUGH,MA 01581. NR 49 TC 10 Z9 10 U1 1 U2 2 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 MAY PY 1997 VL 12 IS 5 BP 1195 EP 1204 DI 10.1557/JMR.1997.0168 PG 10 WC Materials Science, Multidisciplinary SC Materials Science GA WY198 UT WOS:A1997WY19800008 ER PT J AU Hinds, BJ McNeely, RJ Studebaker, DB Marks, TJ Hogan, TP Schindler, JL Kannewurf, CR Zhang, XF Miller, DJ AF Hinds, BJ McNeely, RJ Studebaker, DB Marks, TJ Hogan, TP Schindler, JL Kannewurf, CR Zhang, XF Miller, DJ TI Thin films for superconducting electronics: Precursor performance issues, deposition mechanisms, and superconducting phase formation-processing strategies in the growth of Tl2Ba2CaCu2O8 films by metal-organic chemical vapor deposition SO JOURNAL OF MATERIALS RESEARCH LA English DT Review ID BETA-DIKETONATE COMPLEXES; MICROWAVE SURFACE-RESISTANCE; MICROSTRIP RING-RESONATOR; CU-O SYSTEM; BARIUM PRECURSOR; TRANSMISSION-LINES; LOW-TEMPERATURE; TRANSPORT-PROPERTIES; OXIDE-FILMS; HIGH-POWER AB Epitaxial Tl2Ba2CaCu2O8 thin films with excellent electrical transport characteristics are grown in a two-step process involving metal-organic chemical vapor deposition (MOCVD) of a BaCaCuO(F) thin film followed by a postanneal in the presence of Tl2O vapor. Vapor pressure characteristics of the recently developed liquid metal-organic precursors Ba(hfa)(2) . mep (hfa = hexafluoroacetylacetonate, mep = methylethylpentaglyme), Ca(hfa)(2) . tet (tet = tetraglyme), and the solid precursor Cu(dpm)(2) (dpm = dipivaloylmethanate) are characterized by low pressure thermogravimetric analysis. Under typical film growth conditions, transport is shown to be diffusion limited. The transport rate of Ba(hfa)(2) . mep is demonstrated to be stable for over 85 h at typical MOCVD temperatures (120 degrees C). In contrast, the vapor pressure stability of the commonly used Ba precursor, Ba(dpm)(2), deteriorates rapidly at typical growth temperatures, and the decrease in vapor pressure is approximately exponential with a half-life of similar to 9.4 h. These precursors are employed in a low pressure (5 Torr) horizontal, hot-wall, film growth reactor for growth of BaCaCuO(F) thin films on (110) LaAlO3 substrates. From the dependence of film deposition rate on substrate temperature and precursor partial pressure, the kinetics of deposition are shown to be mass-transport Limited over the temperature range 350-650 degrees C at a 20 nm/min deposition rate. A Ligand exchange process which yields volatile Cu(hfa)(2) and Cu(hfa)(dpm) is also observed under film growth conditions. The MOCVD-derived BaCaCuO(F) films are postannealed in the presence of bulk Tl2Ba2CaCu2O8 at temperatures of 720-890 degrees C in flowing atmospheres ranging from 0-100% O-2. The resulting Tl2Ba2CaCu2O8 films are shown to be epitaxial by x-ray diffraction and transmission electron microscopic (TEM) analysis with the c-axis normal to the substrate surface, with in-plane alignment, and with abrupt him-substrate interfaces. The best films exhibit a T-c = 105 K, transport-measured J(c) = 1.2 x 10(5) A/cm(2) at 77 K, and surface resistances as low as 0.4 m Omega (40 K, 10 GHz). C1 NORTHWESTERN UNIV,SCI & TECHNOL CTR SUPERCONDUCT,EVANSTON,IL 60208. NORTHWESTERN UNIV,DEPT ELECT ENGN & COMP SCI,EVANSTON,IL 60208. ARGONNE NATL LAB,DIV MAT SCI,ARGONNE,IL 60439. ARGONNE NATL LAB,SCI & TECHNOL CTR SUPERCOND,ARGONNE,IL 60439. RP Hinds, BJ (reprint author), NORTHWESTERN UNIV,DEPT CHEM,2145 SHERIDAN RD,EVANSTON,IL 60208, USA. NR 110 TC 44 Z9 44 U1 0 U2 6 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 MAY PY 1997 VL 12 IS 5 BP 1214 EP 1236 DI 10.1557/JMR.1997.0171 PG 23 WC Materials Science, Multidisciplinary SC Materials Science GA WY198 UT WOS:A1997WY19800011 ER PT J AU Tolt, ZL Heatherly, L Clausing, RE Feigerle, CS AF Tolt, ZL Heatherly, L Clausing, RE Feigerle, CS TI Hot filament assisted diamond growth at low temperatures with oxygen addition SO JOURNAL OF MATERIALS RESEARCH LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; MICROWAVE PLASMA AB Addition of a small amount of oxygen to the CH4 and H-2 feed gas permits hot filament assisted chemical vapor deposition (HFCVD) of diamond at significantly lower filament and substrate temperatures. The former can be reduced to as low as 1400 degrees C and the latter to 450 degrees C. The amount of oxygen required is much lower than what has been used in most studies of the oxygen effect. For each CH4%, there is a narrow window in the O/C ratio, where diamond can be deposited at low temperature. This window shifts to higher O/C ratios as the CH4% increases and expands with increases in filament temperature. The effect of changing substrate and filament temperatures on growth rate and film quality are often not consistent with previous experiences with HFCVD of diamond. Increasing the filament temperature does not always improve the growth rate and film quality, and the non-diamond carbon content in the film is dramatically reduced at lower substrate temperatures. Optimum conditions were found that gave reasonable growth rates (similar to 0.5 mu m/h) with high film quality at filament temperatures below 1750 degrees C and substrate temperatures below 600 degrees C. With these reductions in operating temperatures, power consumption can be significantly reduced and the filament lifetime extended indefinitely. 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 19 TC 11 Z9 11 U1 1 U2 2 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 MAY PY 1997 VL 12 IS 5 BP 1344 EP 1350 DI 10.1557/JMR.1997.0183 PG 7 WC Materials Science, Multidisciplinary SC Materials Science GA WY198 UT WOS:A1997WY19800023 ER PT J AU Boyle, TJ AlShareef, HN AF Boyle, TJ AlShareef, HN TI A new and rapid process for production of solution-derived (Pb,La)(Zr,Ti)O-3 thin films and powders SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID PRECURSORS AB A simple and rapid process for synthesizing (Pb,La)(Zr,Ti)O-3 (PZT, PLZT, and PLT) precursor solutions has been developed. This process, termed the ''basic route to PLZT'' (or BRP) process, offers several advantages over standard methods, including rapid solution synthesis (<10 min), use of commercially available materials, film production under ambient conditions, ease of lanthanum dissolution at high concentrations (<1 min), and no heating requirements during solution synthesis. The PLZT precursor solution synthesis involves dissolution of lead acetate (or acetyl acetate) in pyridine followed by addition of a pre-dissolved mixture of titanium and zirconium iso-propoxide in toluene. The lanthanum source can then be added and, depending on the precursor, total synthesis time was <10 min. The preferred lanthanum starting material is a highly soluble bis(isopropyl)aryloxide complex; however, this compound is extremely air and water sensitive. The compositions investigated in this study include PZT 40/60, PLZT 3130/70, 5/30/70, and 10/40/60, and PLT films with 10-20 mol% La. All films were crystallized at 650 degrees C and exhibit ferroelectric properties comparable to films produced by other techniques which require higher crystallization temperatures. RP Boyle, TJ (reprint author), SANDIA NATL LABS,ADV MAT LAB,1001 UNIV BLVD SE,ALBUQUERQUE,NM 87106, USA. RI Alshareef, Husam Niman/A-2000-2015 OI Alshareef, Husam Niman/0000-0001-5029-2142 NR 12 TC 24 Z9 25 U1 1 U2 3 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD MAY 1 PY 1997 VL 32 IS 9 BP 2263 EP 2266 DI 10.1023/A:1018520132376 PG 4 WC Materials Science, Multidisciplinary SC Materials Science GA WY350 UT WOS:A1997WY35000005 ER PT J AU Cheong, Y Du, H Withrow, SP AF Cheong, Y Du, H Withrow, SP TI Reduction of sodium-accelerated oxidation of silicon nitride ceramics by aluminium implantation SO JOURNAL OF MATERIALS SCIENCE LA English DT Article ID TEMPERATURE; CORROSION; KINETICS; SI3N4 AB Norton NBD 200 silicon nitride ceramics were implanted with sodium to a dose of 7.0 x 10(15) cm(-2) at 72 keV (1 at % peak sodium content at 100 nm). The sodium-implanted samples were further implanted with aluminium to 7.3 x 10(-15) cm(-2) at 87 keV (1 at % peak aluminium content at 100 nm). The implanted and unimplanted samples were oxidized in 1 atm dry oxygen at 1100 and 1300 degrees C for 2-6 h. Profilometry and scanning electron microscopy measurements indicated that sodium implantation led to up to a two-fold increase in the oxidation rate of silicon nitride. The sodium effect was effectively neutralized when aluminium was co-implanted. The opposite effects of sodium and aluminium on the oxidation resistance of silicon nitride can be attributed to their different roles in modifying the structure and properties of the oxide formed. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP Cheong, Y (reprint author), STEVENS INST TECHNOL,HOBOKEN,NJ 07030, USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU CHAPMAN HALL LTD PI LONDON PA 2-6 BOUNDARY ROW, LONDON, ENGLAND SE1 8HN SN 0022-2461 J9 J MATER SCI JI J. Mater. Sci. PD MAY 1 PY 1997 VL 32 IS 9 BP 2391 EP 2396 DI 10.1023/A:1018505123716 PG 6 WC Materials Science, Multidisciplinary SC Materials Science GA WY350 UT WOS:A1997WY35000022 ER PT J AU Kim, JH AF Kim, JH TI An asymptotic limit law with a singularly perturbed drift and a random noise SO JOURNAL OF MATHEMATICAL PHYSICS LA English DT Article ID RADIATIVE TRANSPORT-THEORY; POWER STATISTICS; WAVE-PROPAGATION; ONE-DIMENSION AB An asymptotic stochastic initial value problem with a random microscale superposed upon a deterministic macroscale is considered in this article. We derive and prove a limit theorem for the random problem with a rapidly varying deterministic component. The asymptotic character of the stochastic initial value problem with a small parameter is realized by solving a final value problem of which the infinitesimal generator consists of a singularly perturbed deterministic component and a random fluctuation intensity component. We also give an estimate for the error in the asymptotic approximation in terms of the small parameter. This abstract limit theorem is reduced to a limit theorem for the stochastic processes solving a system of stochastic differential equations. The corresponding infinitesimal generator of the Kolmogorov-Fokker-Planck equation is obtained in an asymptotic form and demonstrates how an effective driving farce couples with a zero-mean random perturbation in both drift and diffusion coefficients. Our theorem provides a characterization of random noise for evanescent waves in a layered random medium. (C) 1997 American Institute of Physics. C1 IOWA STATE UNIV SCI & TECHNOL,AMES LAB,US DEPT ENERGY,AMES,IA 50011. NR 21 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 0022-2488 J9 J MATH PHYS JI J. Math. Phys. PD MAY PY 1997 VL 38 IS 5 BP 2660 EP 2675 DI 10.1063/1.531980 PG 16 WC Physics, Mathematical SC Physics GA WW734 UT WOS:A1997WW73400042 ER PT J AU Liu, SV AF Liu, SV TI An improved colorimetric assay for vicinal diol determination by Ti(III) and its utilization for reporting microbial O-demethylation SO JOURNAL OF MICROBIOLOGICAL METHODS LA English DT Article DE colorimetric assay; O-demethylation; phenylmethylethers; protocatechuate; vanillate; Ti(III)-vicinal diol complexation ID ACETOBACTERIUM-WOODII; BACTERIUM; ACIDS AB A simple assay for quantifying O-demethylation activity is desired for investigating the microbial utilization of phenylmethylethers. Detailed experiments showed that the titanium (III) nitrilotriacetate-vicinal diol colorimetric assay produced better results when Ti(III) and vicinal diols were mixed at ratios closer to 1:1 within the appropriate pH range and when the absorbance was measured at the wavelength of maximum absorbance. Vanillate was found to be a better substrate than syringate and ferulate for the determination of O-demethylating activity by Ti(III). The Ti(III) colorimetric assay was sensitive, detecting as low as 10 mu M of vicinal diol. A low concentration (<0.25 mM) of Ti(III) did not inhibit the growth of acetogens on phenylmethylethers. Ti(III) was found as a reliable intrinsic indicator for enumerating O-demethylating microorganisms in environmental samples by the most probable number (MPN) method. The improved Ti(III)-vicinal diol colorimetric assay offers a sensitive, convenient, and cost-effective approach for studying microbial O-demethylation activity and population density. (C) 1997 Elsevier Science B.V. RP Liu, SV (reprint author), OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,OAK RIDGE,TN 37831, USA. NR 14 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-7012 J9 J MICROBIOL METH JI J. Microbiol. Methods PD MAY PY 1997 VL 29 IS 2 BP 85 EP 95 DI 10.1016/S0167-7012(97)00027-4 PG 11 WC Biochemical Research Methods; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA XM163 UT WOS:A1997XM16300003 ER PT J AU Nazikian, R AF Nazikian, R TI Symmetric sideband correlations and the random phase screen approximation SO JOURNAL OF MODERN OPTICS LA English DT Article ID FLUCTUATIONS; PLASMAS AB It is shown that the validity of the random phase screen approximation in coherent wave scattering from random media can be determined from the correlation between symmetric sidebands in the scattered field. Analysis of doublet correlations in microwave reflectometer data taken on the Tokamak Fusion Test Reactor confirms the validity of the model and allows for the numerical back propagation of measurements without the use of imaging optics. RP Nazikian, R (reprint author), PRINCETON UNIV,PLASMA PHYS LAB,POB 451,PRINCETON,NJ 08543, USA. NR 11 TC 7 Z9 7 U1 1 U2 2 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0950-0340 J9 J MOD OPTIC JI J. Mod. Opt. PD MAY PY 1997 VL 44 IS 5 BP 1037 EP 1044 PG 8 WC Optics SC Optics GA WZ590 UT WOS:A1997WZ59000015 ER PT J AU Moss, RL Aizawa, O Beynon, D Brugger, R Constantine, G Harling, O Liu, HB Watkins, P AF Moss, RL Aizawa, O Beynon, D Brugger, R Constantine, G Harling, O Liu, HB Watkins, P TI The requirements and development of neutron beams for neutron capture therapy of brain cancer SO JOURNAL OF NEURO-ONCOLOGY LA English DT Article DE BNCT; epithermal neutrons; neutron beam design ID RESEARCH REACTOR; ENHANCEMENT; DOSIMETRY; DESIGN AB One of the two overriding conditions for successful BNCT is that there must be a sufficient number of thermal neutrons delivered to each of the boronated cells in the tumour bed (target volume). Despite the poor experience with BNCT in the USA some 40 years ago, the continued apparent success of BNCT in Japan since 1968, lead indirectly to the re-start of clinical trials on BNCT in 1994 at both Brookhaven and MIT. Similar trials will start soon at Petten in Europe. At other centres worldwide, many neutron beam designs are being proposed with either thermal or epithermal neutrons, emanating predominately from nuclear research reactors. It is apparent that whilst the success of BNCT depends on a suitable neutron beam, there is a diversity in available designs, as well as each proposed type of neutron source, with consequently different characteristics of the emergent neutron beam. The paper presents the historical development of neutron beams used for BNCT, addresses the requirements on the types of beams, describes some of the existing designs and other proposals elsewhere and lastly, considers the broader requirements in designing NCT facilities. The focus of the paper is on treatment of brain cancer, neutron beam requirements for other types of cancer may vary. C1 AERI,MUSASHI INST TECHNOL,KANAGAWA,JAPAN. UNIV BIRMINGHAM,SCH PHYS & SPACE RES,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. BROOKHAVEN NATL LAB,REACTOR DIV,UPTON,NY 11973. AEA TECHNOL,HARWELL,BERKS,ENGLAND. MIT,NUCL REACTOR LAB,CAMBRIDGE,MA 02139. RP Moss, RL (reprint author), JRC IAM,EUROPEAN COMMISS,HFR UNIT,POB 2,NL-1755 ZG PETTEN,NETHERLANDS. NR 40 TC 35 Z9 38 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD MAY PY 1997 VL 33 IS 1-2 BP 27 EP 40 DI 10.1023/A:1005704911264 PG 14 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA WX655 UT WOS:A1997WX65500004 PM 9151221 ER PT J AU Yang, WL Barth, RF Rotaru, JH Moeschberger, ML Joel, DD Nawrocky, MM Goodman, JH AF Yang, WL Barth, RF Rotaru, JH Moeschberger, ML Joel, DD Nawrocky, MM Goodman, JH TI Enhanced survival of glioma bearing rats following boron neutron capture therapy with blood-brain barrier disruption and intracarotid injection of boronophenylalanine SO JOURNAL OF NEURO-ONCOLOGY LA English DT Article DE boron neutron capture therapy; osmotic blood-brain barrier disruption; boronophenylalanine; glioma ID CENTRAL NERVOUS-SYSTEM; MALIGNANT GLIOMAS; DRUG-DELIVERY; MONOCLONAL-ANTIBODY; TUMORS; CHEMOTHERAPY; GLIOSARCOMAS; XENOGRAFTS; INFUSIONS; EFFICACY AB Boronophenylalanine (BPA) has been used for boron neutron capture therapy (BNCT) of brain tumors in both experimental animals and humans. The purpose of the present study was to determine if the efficacy of BNCT could be enhanced by means of intracarotid (i.c.) injection of BPA with or without blood-brain barrier disruption (BBB-D) and neutron irradiation using a rat brain tumor model. For biodistribution studies, 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 (1.373 mOsmol/ml), followed immediately by i.c. administration of 300, 500 or 800 mg of BPA/kg body weight (b.w.). At the 500 mg dose a fourfold increase in tumor boron concentration (94.5 mu g/g) was seen at 2.5 hours after BBB-D, compared to 20.8 mu g/g in i.v. injected animals. The best composite tumor to normal tissue ratios were observed at 2.5 hours after BBB-D, at which time the tumor: blood (T: Bl) ratio was 10.9, and the tumor: brain (T: Br) ratio was 7.5, compared to 3.2 and 5.0 respectively for i.v. injected rats. In contrast, animals that had received i.c. BPA without BBB-D had T: Bl and T: Br ratios of 8.5 and 5.9, respectively, and the tumor boron concentration was 42.7 mu g/g. For therapy experiments, initiated 14 days after intracerebral implantation of F98 glioma cells, 500mg/kg b.w. of BPA were administered i.v. or i.c. with or without BBB-D, and the animals were irradiated 2.5 hours later at the Brookhaven Medical Research Reactor with a collimated beam of thermal neutrons delivered to the head. The mean survival time for untreated control rats was 24 +/- 3 days, 30 +/- 2 days for irradiated controls, 37 +/- 3 days for those receiving i.v. BPA, 52 +/- 15 days for rats receiving i.c. BPA without BBB-D, and 95 +/- 95 days for BBB-D followed by i.c. BPA and BNCT. The latter group had a 246% increase in life span (ILS) compared to untreated controls and a 124% ILS compared to that of i.v. injected animals. These survival data are the best ever obtained with the F98 glioma model and suggest that i.c. administration of BPA with or without BBB-D may be useful as a means to increase the efficacy of BNCT. C1 OHIO STATE UNIV,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. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 62 TC 22 Z9 26 U1 0 U2 1 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD MAY PY 1997 VL 33 IS 1-2 BP 59 EP 70 DI 10.1023/A:1005769214899 PG 12 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA WX655 UT WOS:A1997WX65500007 PM 9151224 ER PT J AU Gavin, PR Kraft, SL Huiskamp, R Coderre, JA AF Gavin, PR Kraft, SL Huiskamp, R Coderre, JA TI A review: CNS effects and normal tissue tolerance in dogs SO JOURNAL OF NEURO-ONCOLOGY LA English DT Article DE large animal; normal tissue tolerance; BNCT; radiation necrosis ID BORON NEUTRON-CAPTURE; CANINE BRAIN-TUMORS; RADIOTHERAPY; THERAPY; CT AB Large animal studies have been utilized to define tolerance of normal brain to irradiation and verify treatment planning programs with two recently installed epithermal neutron beams. The normal brain tolerance studies utilized two biological endpoints, magnetic resonance visible damage only and neurologic signs progressing to death. The studies focused on defining the proton RBE for the contaminant fast neutrons, and from nitrogen capture of thermal neutrons and boron capture reaction biologic effect. The proton RBE was approximately 3.0 to 6.7, depending on whether a dose reduction factor for the low gamma dose rate was employed. The microscopic distribution of the boron compounds, coupled with the extremely short length of the fission fragments from thermal neutron capture by B-10 yields an observed biologic effect much less than would be expected from such high LET irradiation. This observed biologic effect, which is a product of the microdistribution of the boron atom and the relative biologic effect of the fission fragments has been termed compound factor. The compound factor was based on the calculated physical dose from the fission fragment in blood based on measured blood B-10 concentration. The approximate compound factor for BSH was studied at the two institutions and it ranged from 0.27 to 0.55, depending on the site and the endpoint chosen. The mean compound factor for BPA was only studied at one site and was found to be 1.1 for both endpoints. The increase in the compound factor for BPA is in keeping with previous calculations based on the differences in compound distribution. Results of these studies has helped the initiation of phase I and phase II clinical trials at Brookhaven National Laboratory and the planned European clinical trials at Petten, The Netherlands. C1 KANSAS STATE UNIV, DEPT RADIOL, MANHATTAN, KS 66506 USA. WASHINGTON STATE UNIV, PULLMAN, WA 99164 USA. NETHERLANDS ENERGY RES FDN, DEPT RADIAT TECHNOL, NL-1755 ZG PETTEN, NETHERLANDS. BROOKHAVEN NATL LAB, DEPT MED, UPTON, NY 11973 USA. NR 25 TC 36 Z9 37 U1 0 U2 1 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD MAY PY 1997 VL 33 IS 1-2 BP 71 EP 80 DI 10.1023/A:1005773331737 PG 10 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA WX655 UT WOS:A1997WX65500008 PM 9151225 ER PT J AU Nigg, DW Wheeler, FJ Wessol, DE Capala, J Chadha, M AF Nigg, DW Wheeler, FJ Wessol, DE Capala, J Chadha, M TI Computational dosimetry and treatment planning for boron neutron capture therapy SO JOURNAL OF NEURO-ONCOLOGY LA English DT Article DE boron; neutron; treatment planning; macrodosimetry; BNCT ID DOSE DISTRIBUTION ANALYSIS; RADIOTHERAPY; TRANSPORT AB The technology for computational dosimetry and treatment planning for Boron Neutron Capture Therapy (BNCT) has advanced significantly over the past few years. Because of the more complex nature of the problem, the computational methods that work well for treatment planning in photon radiotherapy are not applicable to BNCT. The necessary methods have, however, been developed and have been successfully employed both for research applications as well as human trials, although further improvements in speed are needed for routine clinical applications. Computational geometry for BNCT applications can be constructed directly from tomographic medical imagery and computed radiation dose distributions can be readily displayed in formats that are familiar to the radiotherapy community. C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. BETH ISRAEL MED CTR,NEW YORK,NY 10003. RP Nigg, DW (reprint author), IDAHO NATL ENGN LAB,POB 1625,MAIL STOP 3870,IDAHO FALLS,ID 83415, USA. NR 32 TC 49 Z9 49 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD MAY PY 1997 VL 33 IS 1-2 BP 93 EP 104 DI 10.1023/A:1005777416716 PG 12 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA WX655 UT WOS:A1997WX65500010 PM 9151227 ER PT J AU Coderre, JA Elowitz, EH Chadha, M Bergland, R Capala, J Joel, DD Liu, HYB Slatkin, DN Chanana, AD AF Coderre, JA Elowitz, EH Chadha, M Bergland, R Capala, J Joel, DD Liu, HYB Slatkin, DN Chanana, AD TI Boron neutron capture therapy for glioblastoma multiforme using p-boronophenylalanine and epithermal neutrons: Trial design and early clinical results SO JOURNAL OF NEURO-ONCOLOGY LA English DT Article DE boron neutron capture therapy; glioblastoma multiforme; boronophenylalanine; phase I/II trial; epithermal neutrons ID BRAIN-TUMORS; ASTROCYTOMAS; COMPLEX AB A Phase I/II clinical trial of boron neutron capture therapy (BNCT) for glioblastoma multiforme is underway using the amino acid analog p-boronophenylalanine (BPA) and the epithermal neutron beam at the Brookhaven Medical Research Reactor. Biodistribution studies were carried out in 18 patients at the time of craniotomy using an i.v. infusion of BPA, solubilized as a fructose complex (BPA-F). There were no toxic effects related to the BPA-F administration at doses of 130, 170, 210, or 250 mg BPA/kg body weight. The tumor/blood, brain/blood and scalp/blood boron concentration ratios were approximately 3.5:1, 1:1 and 1.5:1, respectively. Ten patients have received BNCT following 2-hr infusions of 250 mg BPA/kg body weight. The average boron concentration in the blood during the irradiation was 13.0 +/- 1.5 mu g B-10/g. The prescribed maximum dose to normal brain (1 cm(3) volume) was 10.5 photon-equivalent Gy (Gy-Eq). Estimated maximum and minimum doses (mean +/- sd, n = 10) to the tumor volume were 52.6 +/- 4.9 Gy-Eq (range: 64.4-47.6) and 25.2 +/- 4.2 Gy-Eq (range: 32.3-20.0), respectively). The estimated minimum dose to the target volume (tumor + 2 cm margin) was 12.3 +/- 2.7 Gy-Eq (range: 16.2-7.8). There were no adverse effects on normal brain. The scalp showed mild erythema, followed by epilation in the 8 cm diameter field. Four patients developed recurrent tumor, apparently in the lower dose (deeper) regions of the target volume, at post-BNCT intervals of 7, 5, 3.5 and 3 months, respectively. The remaining patients have had less than 4 months of post-BNCT follow-up. BNCT, at this starting dose level, appears safe. Plans are underway to begin the dose escalation phase of this protocol. C1 BETH ISRAEL MED CTR,DEPT NEUROSURG,NEW YORK,NY 10003. BETH ISRAEL MED CTR,DEPT RADIAT ONCOL,NEW YORK,NY 10003. RP Coderre, JA (reprint author), BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973, USA. NR 27 TC 105 Z9 105 U1 0 U2 4 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD MAY PY 1997 VL 33 IS 1-2 BP 141 EP 152 DI 10.1023/A:1005741919442 PG 12 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA WX655 UT WOS:A1997WX65500014 PM 9151231 ER PT J AU Feinendegen, LE AF Feinendegen, LE TI Strategic planning workshop on research needs for neutron capture therapy SO JOURNAL OF NEURO-ONCOLOGY LA English DT Editorial Material DE workshop neutron capture therapy AB The workshop 'Research Needs for Neutron Capture Therapy', held in Williamsburg, VA, May 9-12, 1995 addressed key issues and questions related to optimization of boron neutron capture therapy (BNCT), in general, and to the possibility of success of the present BNCT trials at the Brookhaven National Laboratory (BNL) and Massachusetts Institute of Technology (MIT), in particular. Both trials use nuclear fission reactors as neutron sources for BNCT of glioblastoma multiforme (BNL) and of deep seated melanoma (MIT). Presentations and discussions focussed on optimal boron-labeled compounds, mainly for brain tumors such as glioblastoma multiforme, and the best mode of compound delivery to the tumor. Also, optimizing neutron irradiation with dose delivery to the tumor cells and the issues of dosimetry of BNCT especially in the brain were discussed. Planning of treatment and of follow-up of patients, coordination of BNCT at various treatment sites, and the potential of delivery BNCT to various types of cancer with an appropriately tailored protocol were additional issues. The need for multicentric interdisciplinary cooperation among the different medical specialties was highlighted. RP Feinendegen, LE (reprint author), US DOE,OFF HLTH & ENVIRONM RES,WASHINGTON,DC 20585, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0167-594X J9 J NEURO-ONCOL JI J. Neuro-Oncol. PD MAY PY 1997 VL 33 IS 1-2 BP 179 EP 185 DI 10.1023/A:1005750105329 PG 7 WC Oncology; Clinical Neurology SC Oncology; Neurosciences & Neurology GA WX655 UT WOS:A1997WX65500018 PM 9151235 ER PT J AU Marshall, CD Speth, JA Payne, SA AF Marshall, CD Speth, JA Payne, SA TI Induced optical absorption in gamma, neutron and ultraviolet irradiated fused quartz and silica SO JOURNAL OF NON-CRYSTALLINE SOLIDS LA English DT Article ID HIGH-PURITY SILICA; EXCIMER LASER; TRANSIENT ABSORPTION; MOLECULAR-DYNAMICS; SIO2; RADIATION; DEFECTS; LUMINESCENCE; DEPENDENCE; GENERATION AB We have investigated the effects of ultraviolet (4.7 eV), gamma (similar to 1 MeV), and neutron (similar to 1 MeV) irradiations on the optical properties of SiO2 glass samples. Samples from various sources were studied, including synthetic fused silicas and natural fused quartz. Several relationships among the different types of ionizing radiation were examined. For example, both UV light and gamma rays convert the germanium impurity to the B, absorption band in fused quartz samples. On the other hand, only neutrons are capable of inducing the oxygen deficient centers (ODCs) with the similar to krad-level doses employed here; the ODCs are produced by way of direct knock-on collisions. The ODCs generated by the neutrons can be converted into E' centers afterwards with gamma-rays. Transient grating and pump-probe optical experiments show that only a small fraction of the induced defect absorption remains permanently, while nearly all recover to the original condition after a UV pulse. Finally, thermal annealing experiments indicate that the radiation-induced defects can be annealed away at temperatures >350 degrees C. We compare the impacts of gamma, neutron, and ultraviolet radiation in terms of the mechanism by which defects are generated. RP Marshall, CD (reprint author), LAWRENCE LIVERMORE NATL LAB,POB 5508,LIVERMORE,CA 94550, USA. NR 36 TC 119 Z9 125 U1 6 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3093 J9 J NON-CRYST SOLIDS JI J. Non-Cryst. Solids PD MAY PY 1997 VL 212 IS 1 BP 59 EP 73 DI 10.1016/S0022-3093(96)00606-0 PG 15 WC Materials Science, Ceramics; Materials Science, Multidisciplinary SC Materials Science GA XA462 UT WOS:A1997XA46200008 ER PT J AU Oversby, VM McPheeters, CC Degueldre, C Paratte, JM AF Oversby, VM McPheeters, CC Degueldre, C Paratte, JM TI Control of civilian plutonium inventories using burning in a non-fertile fuel SO JOURNAL OF NUCLEAR MATERIALS LA English DT Article ID URANIUM AB The increasing inventories of plutonium generated by commercial nuclear power production represent a potential source for proliferation of nuclear weapons. To address this threat we propose separating the plutonium from the other constituents of commercial reactor spent fuel and burning it in a non-fertile fuel based on a zirconium dioxide matrix. The separation can be performed by the Purex process currently in use, but we recommend development of a more compact separation technology that would produce less secondary waste than currently used technology and would allow for more stringent accounting of plutonium inventories. The non-fertile fuel is designed for use in conventional light water power reactors and does not require development of new reactor technology. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. ARGONNE NATL LAB,ARGONNE,IL 60439. PAUL SCHERRER INST,CH-5232 VILLIGEN,SWITZERLAND. NR 19 TC 72 Z9 73 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-3115 J9 J NUCL MATER JI J. Nucl. Mater. PD MAY PY 1997 VL 245 IS 1 BP 17 EP 26 DI 10.1016/S0022-3115(96)00751-9 PG 10 WC Materials Science, Multidisciplinary; Nuclear Science & Technology SC Materials Science; Nuclear Science & Technology GA XB155 UT WOS:A1997XB15500003 ER PT J AU Tornai, MP Levin, CS Hoffman, EJ MacDonald, LR Glass, EC Essner, R Black, KL AF Tornai, MP Levin, CS Hoffman, EJ MacDonald, LR Glass, EC Essner, R Black, KL TI A novel dual detector probe for gamma-ray guided intraoperative beta imaging. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 UNIV CALIF LOS ANGELES,SCH MED,US DOE,DIV NUCL MED & BIOPHYS,LAB STRUCT BIOL & MOL MED,SANTA MONICA,CA. UNIV CALIF LOS ANGELES,SCH MED,DIV NEUROSURG,SANTA MONICA,CA. JOHN WAYNE CANC INST,SANTA MONICA,CA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 21 EP 21 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000021 ER PT J AU Morgan, AE Dewey, SL Alexoff, DL Horan, B Ashby, CR Logan, J Pappas, N Volkow, ND Brodie, JD King, P AF Morgan, AE Dewey, SL Alexoff, DL Horan, B Ashby, CR Logan, J Pappas, N Volkow, ND Brodie, JD King, P TI Vigabatrin attenuates cocaine-induced changes in brain dopamine concentrations. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NYU,SCH MED,NEW YORK,NY. NR 0 TC 1 Z9 1 U1 0 U2 0 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 MAY PY 1997 VL 38 IS 5 SU S BP 33 EP 33 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000033 ER PT J AU Fowler, JS Volkow, ND Logan, J Gatley, SJ Pappas, N King, P Ding, YS Wang, GJ AF Fowler, JS Volkow, ND Logan, J Gatley, SJ Pappas, N King, P Ding, YS Wang, GJ TI Comparison of [C-11]cocaine and [C-11]d-threo-methylphenidate for assessing dopamine transporter (DAT) occupancy by cocaine. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,STONY BROOK,NY 11794. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 34 EP 34 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000034 ER PT J AU Moses, WW Derenzo, SE Gruber, GJ Huesman, RH Budinger, TF AF Moses, WW Derenzo, SE Gruber, GJ Huesman, RH Budinger, TF TI Potential for SPECT cameras utilizing photodiode readout of scintillator crystals. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,DIV LIFE SCI,BERKELEY,CA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 109 EP 109 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000109 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Fischman, M Foltin, R Abumrad, NN Logan, J Pappas, NR AF Wang, GJ Volkow, ND Fowler, JS Fischman, M Foltin, R Abumrad, NN Logan, J Pappas, NR TI Absence of age-related dopamine transporter loss in current cocaine abusers. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. SUNY STONY BROOK,DEPT RADIOL,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. COLUMBIA UNIV,DEPT PSYCHIAT,NEW YORK,NY. NORTHSHORE UNIV HOSP,DEPT SURG,MANHASSET,NY. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 124 EP 124 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000124 ER PT J AU Volkow, ND Fischman, M Wang, GJ Foltin, R Fowler, JS Abumrad, NN Vitkun, S Logan, J Shea, C AF Volkow, ND Fischman, M Wang, GJ Foltin, R Fowler, JS Abumrad, NN Vitkun, S Logan, J Shea, C TI Relationship between cocaine-induced subjective effects and dopamine transporter occupancy. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. COLUMBIA UNIV,NEW YORK,NY. NYS PSYCHIAT INST,NEW YORK,NY. N SHORE UNIV HOSP,CORNELL UNIV MED COLL,DIV BIOSTAT,MANHASSET,NY 11030. NR 0 TC 1 Z9 1 U1 0 U2 0 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 MAY PY 1997 VL 38 IS 5 SU S BP 125 EP 125 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000125 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Logan, J Gatley, SJ Hitzemann, R Chen, A Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Logan, J Gatley, SJ Hitzemann, R Chen, A Pappas, N TI Decreased striatal and enhanced thalamic dopaminergic responsivity in detoxified cocaine abusers. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,STONY BROOK,NY 11794. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 126 EP 126 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000126 ER PT J AU Sloof, GW Comans, EFI Visser, FC Knapp, FF vanLingen, A AF Sloof, GW Comans, EFI Visser, FC Knapp, FF vanLingen, A TI An exponential relationship exists between fatty acid uptake and myocardial blood flow. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 FREE UNIV AMSTERDAM HOSP,AMSTERDAM,NETHERLANDS. OAK RIDGE NATL LAB,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 149 EP 149 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000149 ER PT J AU Majewski, S Boutefnouchet, A Shao, Y Carstens, T Farzanpay, F Ross, J Cherry, SR Silverman, RW Weisenberger, A Wojcik, R AF Majewski, S Boutefnouchet, A Shao, Y Carstens, T Farzanpay, F Ross, J Cherry, SR Silverman, RW Weisenberger, A Wojcik, R TI High resolution LSO PET detector based on the 16 channel Hamamatsu R5900-M16 PMT. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 THOMAS JEFFERSON NATL ACCELERATOR FACIL,DETECTOR GRP,NEWPORT NEWS,VA. UNIV CALIF LOS ANGELES,SCH MED,CRUMP INST BIOL IMAGING,LOS ANGELES,CA. UNIV REGINA,REGINA,SK S4S 0A2,CANADA. NR 0 TC 1 Z9 1 U1 0 U2 0 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 MAY PY 1997 VL 38 IS 5 SU S BP 159 EP 159 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000159 ER PT J AU Atkins, HL Srivastava, SC Krishnamurthy, GT Meinken, GE Mausner, LF Swailem, FM Walsh, TK AF Atkins, HL Srivastava, SC Krishnamurthy, GT Meinken, GE Mausner, LF Swailem, FM Walsh, TK TI Safety and efficacy parameters in patients treated with TIN-117m DTPA. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. VET AFFAIRS MED CTR,TUCSON,AZ. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 166 EP 166 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000166 ER PT J AU Volkow, ND Wang, GJ Fowler, JS Hitzemann, R Pappas, N AF Volkow, ND Wang, GJ Fowler, JS Hitzemann, R Pappas, N TI Enhanced regional brain metabolic responses to benzodiazepines in cocaine abusers. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,STONY BROOK,NY 11794. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 169 EP 169 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000169 ER PT J AU Gatley, SJ Gifford, AN Volkow, ND Fowler, JS Kuhar, MJ Carroll, FI AF Gatley, SJ Gifford, AN Volkow, ND Fowler, JS Kuhar, MJ Carroll, FI TI Dopamine transporter occupancy by RTI-55, inhibition of dopamine transport and stimulation of locomotor activity SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 222 EP 222 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000222 ER PT J AU Luo, H McPherson, DW Beets, AL Knapp, FFR AF Luo, H McPherson, DW Beets, AL Knapp, FFR TI [F-18]-(-,-)-FQNPe - An attractive ligand for evaluation of muscarinic-cholinergic neuron acitivity by PET SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 238 EP 238 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000238 ER PT J AU McPherson, DW Greenbaum, M Beets, AL Luo, H Knapp, FFR AF McPherson, DW Greenbaum, M Beets, AL Luo, H Knapp, FFR TI In vivo evaluation of Z-(R,R)-IQNP as a candidate for the study of M-2 muscarinic receptors by SPECT. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 240 EP 240 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000240 ER PT J AU Gatley, SJ Deng, H Lan, R Hill, WAG Volkow, ND Makriyannis, A AF Gatley, SJ Deng, H Lan, R Hill, WAG Volkow, ND Makriyannis, A TI Novel radiohalogenated ligands for imaging cannabinoid receptors (CBR's) SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. UNIV CONNECTICUT,STORRS,CT 06269. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 282 EP 282 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000282 ER PT J AU Ding, YS Fowler, JS Gatley, SJ Volkow, ND Logan, J Dewey, SL Liang, F Carroll, FI Kuhar, MJ AF Ding, YS Fowler, JS Gatley, SJ Volkow, ND Logan, J Dewey, SL Liang, F Carroll, FI Kuhar, MJ TI PET studies of [18F]norchlorofluoroepibatidine in mapping nicotinic acetylcholine receptors (nAChR). SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. EMORY UNIV,ATLANTA,GA 30322. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 295 EP 295 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000295 ER PT J AU Grillenberger, KG Luckau, D Guhlmann, A Mobus, VJ Knapp, FF Reske, SN AF Grillenberger, KG Luckau, D Guhlmann, A Mobus, VJ Knapp, FF Reske, SN TI Synthesis of N-13-cisplatin (cis-diamminodichlor-platinum) in a full automated chemistry module. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 UNIV HOSP,DEPT NUCL MED,ULM,GERMANY. UNIV HOSP,DEPT GYNECOL,ULM,GERMANY. OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 419 EP 419 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000419 ER PT J AU Huesman, RH Klein, GJ Reutter, BW AF Huesman, RH Klein, GJ Reutter, BW TI Respiratory compensation in cardiac PET using doubly-gated acquisitions. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,CTR FUNCT IMAGING,BERKELEY,CA. NR 0 TC 1 Z9 1 U1 0 U2 0 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 MAY PY 1997 VL 38 IS 5 SU S BP 426 EP 426 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000426 ER PT J AU Gatley, SJ Gifford, AN Lan, R Wong, C Pyatt, B Pappas, N Volkow, ND Hill, WAG Makriyannis, A AF Gatley, SJ Gifford, AN Lan, R Wong, C Pyatt, B Pappas, N Volkow, ND Hill, WAG Makriyannis, A TI SPECT imaging of brain cannabinoid receptors SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 UNIV CONNECTICUT,STORRS,CT. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 434 EP 434 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000434 ER PT J AU Shen, S DeNardo, GL Jones, TD Wilder, RB ODonnell, RT DeNardo, SJ AF Shen, S DeNardo, GL Jones, TD Wilder, RB ODonnell, RT DeNardo, SJ TI A cell-kinetics model for thrombocytopenia after radio-immunotherapy. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 OAK RIDGE NATL LAB,CHEM & BIOL PHYS SECT,OAK RIDGE,TN. UNIV CALIF DAVIS,SCH MED,SACRAMENTO,CA 95817. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 440 EP 440 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000440 ER PT J AU Knapp, FF Guhlke, S Beets, AL Amols, H Weinberger, J AF Knapp, FF Guhlke, S Beets, AL Amols, H Weinberger, J TI Intraarterial irradiation with rhenium-188 for inhibition of restenosis after PTCA - Strategy and evaluation of Re-188-species for rapid urinary excretion. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 COLUMBIA UNIV,NEW YORK,NY 10027. OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 464 EP 464 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000464 ER PT J AU Guhlke, S Beets, AL Biersack, HJ Knapp, FF AF Guhlke, S Beets, AL Biersack, HJ Knapp, FF TI Elution of Re-188 from W-188/Re-188 generators with salts of weak acids permits efficient concentration to low volumes using a new tandem cation/anion exchange system. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 CLIN NUCL MED,BONN,GERMANY. OAK RIDGE NATL LAB,NUCL MED GRP,OAK RIDGE,TN. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 467 EP 467 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000467 ER PT J AU Som, P Oster, ZH Sharma, S Wang, J Rhodes, BA AF Som, P Oster, ZH Sharma, S Wang, J Rhodes, BA TI Diagnosis of osteomyelitis and soft tissue infection using a Tc-99m labeled tuftsin-analog peptide. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 PALATIN TECHNOL,ALBUQUERQUE,NM. SUNY STONY BROOK,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 493 EP 493 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000493 ER PT J AU Patt, BE Iwanczyk, JS Tornai, MP Hoffman, EJ Rossington, C AF Patt, BE Iwanczyk, JS Tornai, MP Hoffman, EJ Rossington, C TI Dedicated breast imaging system based on a novel solid state detector array SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 PHOTON IMAGING INC,LOS ANGELES,CA 90049. UNIV CALIF LOS ANGELES,SCH MED,DEPT PHARMACOL,LOS ANGELES,CA 90024. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 535 EP 535 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000535 ER PT J AU Gatley, SJ Pyatt, B Ding, YS Gifford, AN Fowler, JS Volkow, ND AF Gatley, SJ Pyatt, B Ding, YS Gifford, AN Fowler, JS Volkow, ND TI Preclinical testing of F-18 and I-123 radioligands involving autoradiography and a phosphor-imaging device. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 604 EP 604 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000557 ER PT J AU Sweet, MP Joshi, V Kolsky, KL Mausner, LF Srivastava, SC AF Sweet, MP Joshi, V Kolsky, KL Mausner, LF Srivastava, SC TI Development and evaluation of In-111 and Sc-47 labeled cyclohexyl DOTA immunoconjugates. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 809 EP 809 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000715 ER PT J AU Kolsky, KL Joshi, V Martin, T Meinken, GE Mausner, LF Srivastava, SC AF Kolsky, KL Joshi, V Martin, T Meinken, GE Mausner, LF Srivastava, SC TI Optimization of the radiochemical processing of Sc-47 for radioimmunotherapy. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 826 EP 826 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000732 ER PT J AU Reutter, BW Klein, GJ Huesman, RH AF Reutter, BW Klein, GJ Huesman, RH TI Respiration-compensated cardiac PET attenuation correction via automated 4-D segmentation of gated transmission images SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 UNIV CALIF BERKELEY,CTR FUNCT IMAGING,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 867 EP 867 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000773 ER PT J AU Li, J Liang, Z Kuan, H Wong, C Cheng, J Wang, G Schlyer, D Volkow, N Harrington, D AF Li, J Liang, Z Kuan, H Wong, C Cheng, J Wang, G Schlyer, D Volkow, N Harrington, D TI A collimator-specific treatment of Data for F-18 SPECT imaging. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 SUNY STONY BROOK,STONY BROOK,NY 11794. BROOKHAVEN NATL LAB,NEW YORK,NY. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 900 EP 900 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000806 ER PT J AU Huesman, RH Reutter, BW Zeng, GL Gullberg, GT AF Huesman, RH Reutter, BW Zeng, GL Gullberg, GT TI Kinetic parameter estimation from SPECT projection measurements. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 LAWRENCE BERKELEY LAB,BERKELEY,CA. UNIV UTAH,SALT LAKE CITY,UT 84112. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 946 EP 946 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000852 ER PT J AU Sparks, RB Siegel, JA AF Sparks, RB Siegel, JA TI Comparison of point source and Monte Carlo methods in determining dose per unit cumulated activity from exposure to patients administered radioactive material. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 OAK RIDGE INST SCI & EDUC,OAK RIDGE,TN. NUCL PHYS ENTERPRISES,VOORHEES,NJ. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 968 EP 968 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98000874 ER PT J AU Logan, J Volkow, ND Fowler, JS Wang, GJ Gatley, SJ Fischman, M Foltin, R AF Logan, J Volkow, ND Fowler, JS Wang, GJ Gatley, SJ Fischman, M Foltin, R TI Estimating the concentration and degree of occupancy of dopamine transporters (DAT) in cocaine abusers SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. SUNY STONY BROOK,STONY BROOK,NY 11794. COLUMBIA UNIV,NEW YORK,NY 10032. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 1184 EP 1184 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98001090 ER PT J AU Wang, GJ Volkow, ND Fowler, JS Hitzemann, RJ Pappas, N Piscani, K AF Wang, GJ Volkow, ND Fowler, JS Hitzemann, RJ Pappas, N Piscani, K TI Gender differences in cerebellar metabolic responses to lorazepam. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. BROOKHAVEN NATL LAB,DEPT CHEM,UPTON,NY 11973. SUNY STONY BROOK,DEPT RADIOL,STONY BROOK,NY 11794. SUNY STONY BROOK,DEPT PSYCHIAT,STONY BROOK,NY 11794. VAMC,PSYCHIAT SERV,NORTHPORT,NY. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 1191 EP 1191 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98001097 ER PT J AU Gifford, AN Gatley, SJ Volkow, ND AF Gifford, AN Gatley, SJ Volkow, ND TI Comparison of the in vivo and in vitro time course of binding of a high affinity radioligand. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,DEPT MED,UPTON,NY 11973. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 1201 EP 1201 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98001107 ER PT J AU Tan, PZ Baldwin, RM vanDyck, CH Amici, L AlTikriti, M Roth, B Khan, N Fowler, JS Shea, C Soufer, R Charney, DS Innis, RB AF Tan, PZ Baldwin, RM vanDyck, CH Amici, L AlTikriti, M Roth, B Khan, N Fowler, JS Shea, C Soufer, R Charney, DS Innis, RB TI Identity and receptor binding of radiometabolites of the 5-HT2A/2C ligand [F-18]altanserin. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. YALE VET ADM PET CTR,W HAVEN,CT. CASE WESTERN RESERVE UNIV,SCH MED,CLEVELAND,OH 44106. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 1206 EP 1206 PG 1 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98001112 ER PT J AU Molina, P Ding, YS Carroll, FI Liang, F Volkow, N Kuhar, M Pappas, N King, P Abumrad, N Fowler, JS AF Molina, P Ding, YS Carroll, FI Liang, F Volkow, N Kuhar, M Pappas, N King, P Abumrad, N Fowler, JS TI [F-18]norchlorofluorepibatidine (NFED): Preclinical toxicological studies. SO JOURNAL OF NUCLEAR MEDICINE LA English DT Meeting Abstract C1 BROOKHAVEN NATL LAB,UPTON,NY 11973. N SHORE UNIV HOSP,MANHASSET,NY 11030. SUNY STONY BROOK,STONY BROOK,NY 11794. RES TRIANGLE INST,RES TRIANGLE PK,NC 27709. EMORY UNIV,ATLANTA,GA 30322. NR 0 TC 0 Z9 0 U1 1 U2 1 PU SOC NUCLEAR MEDICINE INC PI RESTON PA 1850 SAMUEL MORSE DR, RESTON, VA 20190-5316 SN 0161-5505 J9 J NUCL MED JI J. Nucl. Med. PD MAY PY 1997 VL 38 IS 5 SU S BP 1209 EP 1209 PG 2 WC Radiology, Nuclear Medicine & Medical Imaging SC Radiology, Nuclear Medicine & Medical Imaging GA WY980 UT WOS:A1997WY98001115 ER PT J AU Eto, M Ishiyama, S Burchell, TD Yahr, GT AF Eto, M Ishiyama, S Burchell, TD Yahr, GT TI Biaxial strength and fracture criterion for HTGR graphites SO JOURNAL OF NUCLEAR SCIENCE AND TECHNOLOGY LA English DT Article DE HTGR type reactors; graphite component; nuclear graphite; biaxial strength; fracture criterion; fractures; failure surface AB The strength and fracture criterion at the biaxial stress state were examined for two grades of HTGR graphites, a fine-grained isotropic IG-11 and a medium-grained semi-isotropic PGX. Two types of specimens different in size were tested. The biaxial stress state was realized using a servohydraulic testing machine in combination with an apparatus for applying internal pressure or torque force to a tubular specimen. Main results are: (1) On the basis of the statistical analysis of the data on the smaller IG-11 specimens, the maximum strain energy criterion gave the best fit to the data points both in the first and fourth quadrants of the failure surface. (2) The data on the larger specimens obtained at ORNL fell on the scatter band of the JAERI datal which indicated that no appreciable difference in the biaxial strength of IG-11 graphite was found despite the difference in the test fixture and specimen dimensions. (3) The maximum strain energy criterion was also believed to be most appropriate for PGX graphite for the first quadrant of the failure surface. C1 OAK RIDGE NATL LAB, OAK RIDGE, TN 37831 USA. RP JAPAN ATOM ENERGY RES INST, DEPT MAT SCI & ENGN, TOKAI RES ESTAB, TOKAI, IBARAKI 31911, JAPAN. RI Burchell, Tim/E-6566-2017 OI Burchell, Tim/0000-0003-1436-1192 NR 10 TC 3 Z9 3 U1 0 U2 3 PU TAYLOR & FRANCIS LTD PI ABINGDON PA 2-4 PARK SQUARE, MILTON PARK, ABINGDON OR14 4RN, OXON, ENGLAND SN 0022-3131 EI 1881-1248 J9 J NUCL SCI TECHNOL JI J. Nucl. Sci. Technol. PD MAY PY 1997 VL 34 IS 5 BP 476 EP 483 DI 10.1080/18811248.1997.9733694 PG 8 WC Nuclear Science & Technology SC Nuclear Science & Technology GA XG943 UT WOS:A1997XG94300007 ER PT J AU Wu, PT Houstis, EN AF Wu, PT Houstis, EN TI EPPOD: A problem solving environment for parallel electronic prototyping of physical object design SO JOURNAL OF PARALLEL AND DISTRIBUTED COMPUTING LA English DT Article ID STRUCTURAL SHAPE OPTIMIZATION AB One of the grand challenges for computer applications is the creation of a system that will provide accurate computer simulations of physical objects coupled with powerful design optimization tools to allow optimum prototyping and the final design of a broad range of physical objects, We refer to such a software environment as electronic prototyping for physical object design (EPPOD), The research challenges in building such systems are in software integration, in utilizing massive parallelism to satisfy their large computational requirements, in incorporating knowledge into the entire electronic prototyping process, in creating intelligent user interfaces for such systems, and in advancing the algorithmic infrastructure needed to support the desired functionality, In this paper we address issues related to the parallel processing of the computationally intensive components of the EPPOD problem solving environment on message passing parallel machines and present its software architecture, The parallel methodology adopted to map the underlying computations to parallel machines is based on the optimal decomposition of continuous and discrete geometric data associated with the physical object, One of the main goals of this methodology is the reuse of existing software parts while implementing various components of the EPPOD system on parallel computational environments, Finally, some performance data of the parallel algorithmic infrastructured developed are listed and discussed, (C) 1997 Academic Press. C1 PURDUE UNIV, DEPT COMP SCI, W LAFAYETTE, IN 47907 USA. RP Wu, PT (reprint author), ARGONNE NATL LAB, DIV MATH & COMP SCI, 9700 S CASS AVE, ARGONNE, IL 60439 USA. NR 23 TC 1 Z9 1 U1 0 U2 2 PU ACADEMIC PRESS INC ELSEVIER SCIENCE PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0743-7315 J9 J PARALLEL DISTR COM JI J. Parallel Distrib. Comput. PD MAY 1 PY 1997 VL 42 IS 2 BP 157 EP 172 DI 10.1006/jpdc.1997.1323 PG 16 WC Computer Science, Theory & Methods SC Computer Science GA XT266 UT WOS:A1997XT26600006 ER PT J AU Nunes, JA Tong, WG Chandler, DW Rahn, LA AF Nunes, JA Tong, WG Chandler, DW Rahn, LA TI Circular dichroism spectroscopy by four-wave mixing using polarization grating-induced thermal gratings SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID OPTICAL-PHASE CONJUGATION; DEMOUNTABLE CATHODE-DISCHARGE; LIQUID-CHROMATOGRAPHY; DEGENERATE; FLAME; TRANSITION; CELL AB A novel four-wave mixing technique for the measurement of circular dichroism in optically active liquid samples is demonstrated. When two cross-polarized continuous-wave laser beams are crossed at a small angle in a circular dichroic liquid, a weak thermal grating is produced with a phase depending on the sign of the circular dichroism. The polarization of one of the beams can be modified to allow coherent interference with an intensity grating-induced thermal grating. A probe beam scattering from the composite grating results in a coherent signal beam that reveals the sign and the magnitude of analyte circular dichroism. The use of this technique to optimize the signal-to-noise ratio in the presence of scattered light and laser noise is discussed. C1 SAN DIEGO STATE UNIV,DEPT CHEM,SAN DIEGO,CA 92182. SANDIA NATL LABS,COMBUST RES FACIL,LIVERMORE,CA 94551. OI Rahn, Larry/0000-0002-4793-1158 NR 31 TC 10 Z9 10 U1 3 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD MAY 1 PY 1997 VL 101 IS 18 BP 3279 EP 3283 DI 10.1021/jp963813b PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA WX119 UT WOS:A1997WX11900013 ER PT J AU Hitchcock, AP Urquhart, SG Wen, AT Kilcoyne, ALD Tyliszczak, T Ruhl, E Kosugi, N Bozek, JD Spencer, JT McIlroy, DN Dowben, PA AF Hitchcock, AP Urquhart, SG Wen, AT Kilcoyne, ALD Tyliszczak, T Ruhl, E Kosugi, N Bozek, JD Spencer, JT McIlroy, DN Dowben, PA TI Inner-shell excitation spectroscopy of closo-carboranes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID CHEMICAL-VAPOR-DEPOSITION; BORON-CARBIDE; SYNCHROTRON-RADIATION; HIGH-RESOLUTION; SELECTIVE-AREA; VALENCE-SHELL; SPECTRA; ADSORPTION; ICOSAHEDRA; BORANES AB Oscillator strength spectra in the region of B 1s and C 1s excitation of three isomeric carborane cage compounds [closo-1,2-orthocarborane, closo-1,7-metacarborane, closo-1,12-paracarborane (C2B10H12)] have been derived from inner-shell electron energy loss spectra (ISEELS) recorded under electric dipole-scattering conditions. Total ion yield spectra recorded at high resolution with synchrotron radiation are also reported. The spectral features are assigned on the basis of comparisons with spectral predictions derived from the results of ab initio and semiempirical (extended Huckel) molecular orbital calculations. The isomeric and core level variations in the discrete core excitations are related to changes in orbital symmetries as well as variations in electron localization in these isomers. The ionization efficiency in the region of the B 1s and C 1s edges is derived. C1 UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,ADV LIGHT SOURCE,BERKELEY,CA 91420. UNIV NEBRASKA,CTR MAT RES & ANAL,LINCOLN,NE 68588. UNIV MAINZ,INST PHYS,D-55099 MAINZ,GERMANY. INST MOL SCI,OKAZAKI,AICHI 444,JAPAN. SYRACUSE UNIV,DEPT CHEM,SYRACUSE,NY 13244. SYRACUSE UNIV,WM KECK CTR MOL ELECT,SYRACUSE,NY 13244. RP Hitchcock, AP (reprint author), MCMASTER UNIV,DEPT CHEM,1280 MAIN ST W,HAMILTON,ON L8S 4M1,CANADA. RI Bozek, John/E-4689-2010; Urquhart, Stephen/A-6237-2014; Bozek, John/E-9260-2010; Kilcoyne, David/I-1465-2013 OI Urquhart, Stephen/0000-0002-6415-6341; Bozek, John/0000-0001-7486-7238; NR 66 TC 31 Z9 31 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 MAY 1 PY 1997 VL 101 IS 18 BP 3483 EP 3493 DI 10.1021/jp9622849 PG 11 WC Chemistry, Physical SC Chemistry GA WX113 UT WOS:A1997WX11300007 ER PT J AU Petrenko, SV Pitzer, KS AF Petrenko, SV Pitzer, KS TI Thermodynamics of aqueous NaOH over the complete composition range and to 523 K and 400 MPa SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SODIUM-HYDROXIDE; PARTIAL PRESSURES; IONIC-SOLUTIONS; MULTICOMPONENT; ELECTROLYTES; SYSTEM; TEMPERATURE; EQUATIONS; POTASSIUM; MIXTURES AB The thermodynamic properties of aqueous NaOH are represented for the entire range to extremely high concentration by mole fraction based equations. The apparent molar volume and the solvent and solute activities are obtained from literature values based on experimental measurements extending over the ranges 273-523 K and 0-400 MPa. For the range below 6 mol kg(-1) the values from the very comprehensive treatment of Simonson et al. are given high weight. At the highest temperature the dissociated mole fraction of NaOH extends to 0.9. The equations represent the data satisfactorily over this very wide range and are of a form readily extended to more complex mixed systems and to solubility calculations. C1 UNIV CALIF BERKELEY,DEPT CHEM,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,BERKELEY,CA 94720. NR 34 TC 17 Z9 19 U1 0 U2 8 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 MAY 1 PY 1997 VL 101 IS 18 BP 3589 EP 3595 DI 10.1021/jp963707+ PG 7 WC Chemistry, Physical SC Chemistry GA WX113 UT WOS:A1997WX11300022 ER PT J AU Enderlein, J Robbins, DL Ambrose, WP Goodwin, PM Keller, RA AF Enderlein, J Robbins, DL Ambrose, WP Goodwin, PM Keller, RA TI Statistics of single-molecule detection SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID LASER-INDUCED FLUORESCENCE; DETECTION LIMITS; FLOW-CYTOMETRY; ELECTROPHORESIS; BIOTECHNOLOGY; CAPILLARY; FRAGMENTS AB A new mathematical approach for the calculation of the photon detection statistics in single-molecule detection experiments is presented. The approach is based on a path integral representation of the involved probability distributions. A numerical Monte Carlo sampling method for computing the involved path integrals is given. The general ideas are applied to the modeling of measured burst size distributions in single-molecule detection experiments with B-phycoerythrin. RP Enderlein, J (reprint author), LOS ALAMOS NATL LAB,CST 1,MS M888,LOS ALAMOS,NM 87545, USA. NR 47 TC 24 Z9 24 U1 0 U2 14 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 MAY 1 PY 1997 VL 101 IS 18 BP 3626 EP 3632 DI 10.1021/jp963261x PG 7 WC Chemistry, Physical SC Chemistry GA WX113 UT WOS:A1997WX11300027 ER PT J AU Zhu, S Chen, SS Cai, Y AF Zhu, S Chen, SS Cai, Y TI Vibration and stability of two tubes in cross-flow SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference CY JUL 23-27, 1995 CL HONOLULU, HI SP Amer Soc Mech Engineers AB Two tubes in tandem and normal to flow were studied on the basis of the unsteady-flow theory. Motion-dependent fluid forces were measured in a water channel, and the pitch-to-diameter ratio was 1.35. From the measured fluid forces, fluid damping and stiffness were calculated as a function of reduced flow velocity and several Reynolds numbers. Once the fluid-damping and fluid-stiffness coefficients are known, coupled vibration and stability of the two tubes in cross-flow can be predicted. RP Zhu, S (reprint author), ARGONNE NATL LAB,DIV ENERGY TECHNOL,BLDG 335,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 12 TC 8 Z9 8 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 142 EP 149 DI 10.1115/1.2842275 PG 8 WC Engineering, Mechanical SC Engineering GA XA725 UT WOS:A1997XA72500002 ER PT J AU Yahr, GT AF Yahr, GT TI Prevention of nonductile fracture in 6061-T6 aluminum nuclear pressure vessels SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference of the American-Society-of-Mechanical-Engineers CY JUL 23-27, 1995 CL HONOLULU, HI SP Amer Soc Mech Engineers AB The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Committee has approved rules for the use of 6061-T6 and 6061-T651 aluminum for the construction of Class I welded nuclear pressure vessels for temperatures not exceeding 149 degrees C (300 degrees F). Nuclear Code Case N-519 will allow the use of this aluminum in the construction of low-temperature research reactors such as the Advanced Neutron Source. The rules for protection against nonductile fracture are discussed. The basis for a value of 25.3 MPa root m (23 ksi root in.) for the critical or reference stress intensity factor for use in the fracture analysis is presented. Requirements for consideration of the effects of neutron irradiation on the fracture toughness are discussed. RP MARTIN MARIETTA ENERGY SYST INC, OAK RIDGE NATL LAB, ENGN TECHNOL DIV, OAK RIDGE, TN 37831 USA. NR 32 TC 0 Z9 0 U1 0 U2 3 PU ASME PI NEW YORK PA TWO PARK AVE, NEW YORK, NY 10016-5990 USA SN 0094-9930 EI 1528-8978 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 150 EP 156 DI 10.1115/1.2842276 PG 7 WC Engineering, Mechanical SC Engineering GA XA725 UT WOS:A1997XA72500003 ER PT J AU Swinson, WF Battiste, RL Yahr, GT AF Swinson, WF Battiste, RL Yahr, GT TI An experimental investigation of the interaction of primary and secondary stresses in fuel plates SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference CY JUL 21-26, 1996 CL MONTREAL, CANADA SP Amer Soc Mech Engineers AB If the load is not relieved as a structure starts to yield, the induced stress is defined as primary stress. If the load relaxes, as a structure begins to yield the induced stress is defined as secondary stress. In design, it is not uncommon to give more weight to primary stresses than to secondary stresses., However, knowing when this is good design practice and when it is not good design practice represents a problem. In particular, the fuel plates in operating reactors contain both primary stresses and secondary stresses, and to properly assess a design there is a need to assign design weights to the stresses. Tests were conducted on reactor fuel plates intended for the advanced neutron source (ANS) to determine the potential of giving different design weights to the primary and secondary stresses. The results of these tests and the conclusion that the stresses should be weighted the same are given in this paper. RP Swinson, WF (reprint author), OAK RIDGE NATL LAB,ENGN TECHNOL DIV,POB 2009,OAK RIDGE,TN 37831, USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 207 EP 210 DI 10.1115/1.2842285 PG 4 WC Engineering, Mechanical SC Engineering GA XA725 UT WOS:A1997XA72500012 ER PT J AU Yahr, GT AF Yahr, GT TI Fatigue design curves for 6061-T6 aluminum SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference CY JUL 25-29, 1993 CL DENVER, CO AB A request has been made to the ASME Boiler and Pressure Vessel Committee that 6061-T6 aluminum be approved for use in the construction of Class I welded nuclear vessels so it can be used for the pressure vessel of the Advanced Neutron Source research reactor. Fatigue design curves with and without mean stress effects have been proposed. A knock-down factor of 2 is applied to the design curve for evaluation of welds. The basis of the curves is explained. The fatigue design curves are compared to fatigue data from base metal and weldments. RP Yahr, GT (reprint author), OAK RIDGE NATL LAB,ENGN TECHNOL DIV,POB 2009,OAK RIDGE,TN 37831, USA. NR 16 TC 6 Z9 6 U1 1 U2 3 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 211 EP 215 DI 10.1115/1.2842286 PG 5 WC Engineering, Mechanical SC Engineering GA XA725 UT WOS:A1997XA72500013 ER PT J AU Keeney, JA Bass, BR AF Keeney, JA Bass, BR TI Fracture analysis of multiple cracks in a spinning cylinder experiment SO JOURNAL OF PRESSURE VESSEL TECHNOLOGY-TRANSACTIONS OF THE ASME LA English DT Article; Proceedings Paper CT Pressure Vessels and Piping Conference CY JUL 21-26, 1996 CL MONTREAL, CANADA SP Amer Soc Mech Engineers AB This paper presents finite-element analyses of the cylinder specimen being used in the international Network for Evaluating Steel Components (NESC) large-scale spinning-cylinder project (NESC-1). The NESC was organized as an international forum to exchange information on procedures for structural integrity assessment, fi, collaborate on specific projects, and to promote the harmonization of international standards. The objective of the NESC-1 project is to focus on a complete procedure for assessing the structural integrity of aged reactor pressure vessels. Current plans for the testing program call for two large cracks to be installed in the NESC-1 cylinder separated by 90 deg. Three-dimensional finite-element analyses were carried out to determine: 1) the extent of interaction between multiple cracks in the cylinder; and 2) the predicted effects of using an initial cylinder temperature of 295 degrees C and coolant temperature of 5 degrees C in the experiment. The cylinder was modeled with inner-surface through-clad cracks having a depth of 74 mm and aspect ratio of 2:1. The cylinder specimen was subjected to centrifugal lending followed by a thermal shock and analyzed with a thermo-elastic-plastic material model. The analytical results indicate that the stress-intensity factor changes less than 0.2 percent between a model with one crack and a model with four crack evenly spaced around the circumference. Cleavage initiation is likely to be achieved for initial and coolant temperatures of 295 and 5 degrees C, respectively. RP Keeney, JA (reprint author), OAK RIDGE NATL LAB,POB 2009,OAK RIDGE,TN 37831, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0094-9930 J9 J PRESS VESS-T ASME JI J. Press. Vessel Technol.-Trans. ASME PD MAY PY 1997 VL 119 IS 2 BP 232 EP 235 DI 10.1115/1.2842290 PG 4 WC Engineering, Mechanical SC Engineering GA XA725 UT WOS:A1997XA72500017 ER PT J AU Kammash, T Lee, MJ Poston, DI AF Kammash, T Lee, MJ Poston, DI TI High-thrust high-specific impulse gasdynamic fusion propulsion system SO JOURNAL OF PROPULSION AND POWER LA English DT Article ID MIRROR AB The gasdynamic fusion propulsion system utilizes a simple mirror magnetic geometry in which a high-density plasma is confined long enough to generate fusion energy while ejecting charged particles through one end to generate thrust, At high densities the collision mean free path becomes much shorter than the length, making the plasma behave much like a continuous medium, a fluid, Under these conditions the escape of the plasma is analogous to the flow of a gas into a vacuum from a vessel with a hole, With the mirror serving as a magnetic nozzle the plasma-charged particles are ejected at very high energies, giving rise to specific impulses of well over 200,000 s, but at modest thrusts because of the smallness of their mass. We examine methods by which the thrust of this engine can be enhanced, On the one hand we explore the use of a hydrogen propellant that Is heated by the radiation emanating from the plasma, which, upon exhausting through a nozzle, generates the additional thrust, On the other hand we focus purely on changing the properties of the injected plasma to achieve the same objectives, We find in the case of a deuterium-tritium plasma that the use of hydrogen results in a degradation of the propulsive capability of the system, but we find it quite suitable for an engine that burns a mixture of deuterium and helium 3. The same results can be achieved by simply increasing the density of the injected plasma without encountering major adverse consequences, Because of engineering considerations, however, the use of a hydrogen propellant may prove to be inevitable if no other means are found to protect the walls of the reactor chamber against large heat loads. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Kammash, T (reprint author), UNIV MICHIGAN,TECH STAFF,ANN ARBOR,MI 48109, USA. NR 16 TC 10 Z9 10 U1 1 U2 2 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAY-JUN PY 1997 VL 13 IS 3 BP 421 EP 427 DI 10.2514/2.5180 PG 7 WC Engineering, Aerospace SC Engineering GA WZ022 UT WOS:A1997WZ02200014 ER PT J AU Brewster, MQ Son, SF AF Brewster, MQ Son, SF TI Intrinsic combustion instability of solid energetic materials - Comment SO JOURNAL OF PROPULSION AND POWER LA English DT Article C1 LOS ALAMOS NATL LAB,EXPLOS GRP,LOS ALAMOS,NM 87545. RP Brewster, MQ (reprint author), UNIV ILLINOIS,DEPT MECH & IND ENGN,1206 W GREEN ST,URBANA,IL 61801, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0748-4658 J9 J PROPUL POWER JI J. Propul. Power PD MAY-JUN PY 1997 VL 13 IS 3 BP 454 EP 456 DI 10.2514/2.5188 PG 3 WC Engineering, Aerospace SC Engineering GA WZ022 UT WOS:A1997WZ02200021 ER PT J AU Paul, PH AF Paul, PH TI Calculation of transition frequencies and rotational line strengths in the gamma-bands of nitric oxide SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID LASER-INDUCED FLUORESCENCE; EINSTEIN COEFFICIENTS; MOLECULAR-CONSTANTS; ABSORPTION-LINES; NO MOLECULE; TEMPERATURE; SYSTEM; SHIFT; PROBABILITIES; SPECTROSCOPY AB A summary of the relations and spectroscopic parameters required for the accurate prediction of transition frequencies and rotational line strengths of the gamma bands of NO is presented. Relations for the rotational line strengths are given that include the effects of finite centrifugal distortion, higher order pin-orbit coupling and lambda-doubling, The effect of these corrections on the calculated line strengths is considered. The magnitude of these corrections is found to increase with rotational number to levels of 5-15% for values of J > 50, the corrections being more prominent in satellite than in main branch transitions. RP Paul, PH (reprint author), SANDIA NATL LABS,LIVERMORE,CA 94550, USA. NR 44 TC 30 Z9 30 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAY PY 1997 VL 57 IS 5 BP 581 EP 589 DI 10.1016/S0022-4073(96)00158-6 PG 9 WC Optics; Spectroscopy SC Optics; Spectroscopy GA XE751 UT WOS:A1997XE75100001 ER PT J AU Patel, PK Wark, JS Heading, DJ Djaoui, A Rose, SJ Renner, O Hauer, A AF Patel, PK Wark, JS Heading, DJ Djaoui, A Rose, SJ Renner, O Hauer, A TI Simulation of X-ray line transfer in a cylindrically expanding plasma SO JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER LA English DT Article ID LASER-PRODUCED-PLASMAS; ESCAPE PROBABILITIES; VELOCITY-GRADIENTS; SPECTROSCOPY; IONIZATION; DRIVEN; MODELS; MEDIA AB A method for calculating the X-ray resonance line emission from a cylindrically expanding laser-produced plasma is presented. A multi-frequency line transfer algorithm, incorporated as a post-processor to a time-dependent 1-D hydrodynamics and non-LTE atomic physics calculation, is used to compute spatially-resolved spectral profiles of the line emission. Coupling of photon re-absorption to ionic state populations is achieved by use of the escape probability method. We use the code to investigate the effects of high expansion velocities, and the influence of neighbouring lines, on the opacity and detailed shape of optically thick lines. As an example we consider the profile of the Lyman-alpha (1s-2p) resonance line of hydrogenic aluminium. (C) 1997 Elsevier Science Ltd. C1 RUTHERFORD APPLETON LAB,DIDCOT OX11 0QX,OXON,ENGLAND. ACAD SCI CZECH REPUBL,INST PHYS,CZ-18040 PRAGUE,CZECH REPUBLIC. LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. RP Patel, PK (reprint author), UNIV OXFORD,CLARENDON LAB,DEPT PHYS,PARKS RD,OXFORD OX1 3PU,ENGLAND. RI Patel, Pravesh/E-1400-2011; Renner, Oldrich/C-1591-2010 OI Renner, Oldrich/0000-0003-4942-2637 NR 33 TC 20 Z9 20 U1 1 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0022-4073 J9 J QUANT SPECTROSC RA JI J. Quant. Spectrosc. Radiat. Transf. PD MAY PY 1997 VL 57 IS 5 BP 683 EP 694 DI 10.1016/S0022-4073(96)00126-4 PG 12 WC Optics; Spectroscopy SC Optics; Spectroscopy GA XE751 UT WOS:A1997XE75100008 ER PT J AU Mong, GM Campbell, JA Orr, RD Clauss, SA Wahl, KL Hoopes, FV AF Mong, GM Campbell, JA Orr, RD Clauss, SA Wahl, KL Hoopes, FV TI Activity reduction of radioactive mixed wastes for subsequent carboxylate determinations SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article AB Tank wastes are usually very basic, pH > 12, and extremely radioactive. An ion exchange method for removing most of the radioactive components has been developed. The sample can then be removed from the hot cell facility to be analyzed for chelator, chelator fragments, and low-molecular weight acids. The use of cation exchange resin in the sample preparation does not introduce or remove any organic carbon. C1 PACIFIC NW NATL LAB,ADV ORGAN ANALYT METHODS GRP,RICHLAND,WA 99352. NR 6 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAY PY 1997 VL 219 IS 1 BP 41 EP 45 DI 10.1007/BF02040262 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV486 UT WOS:A1997XV48600006 ER PT J AU Kinard, WF Bibler, NE Coleman, CJ Dewberry, RA AF Kinard, WF Bibler, NE Coleman, CJ Dewberry, RA TI Radiochemical analyses for the defense waste processing facility startup at the Savannah River Site SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on Research and Education in Radioanalytical Chemistry, at the American-Chemical-Society Meeting CY MAR 24-26, 1996 CL NEW ORLEANS, LA SP Amer Chem Soc ID PLASMA-MASS SPECTROMETRY AB Highly radioactive waste from defense-related activities at the Savannah River Site in South Carolina are to be incorporated into a borosilicate glass in the Defense Waste Processing Facility (DWPF) for long-term geological isolation. Processing and repository safety considerations require the determination of 24 radioisotopes that meet the reporting criteria. These isotopes include fission products, activation products, and daughter nuclei that grow into the waste. Four isotopes, Cs-137, Sr-90,, Pu-238 and U-238 will be routinely measured in the DWPF operation for process control. ?his work shows that the concentrations of the other 20 reportable radioisotopes in the final glass product can be predicted from a thorough characterization of the high level waste (HLW) tanks and a knowledge of the concentrations of the major non-radioactive components in the vitrification process. C1 WESTINGHOUSE SAVANNAH RIVER CO,SAVANNAH RIVER TECHNOL CTR,AIKEN,SC 29802. RP Kinard, WF (reprint author), COLL CHARLESTON,DEPT CHEM & BIOCHEM,CHARLESTON,SC 29424, USA. NR 11 TC 11 Z9 14 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAY PY 1997 VL 219 IS 2 BP 197 EP 201 DI 10.1007/BF02038500 PG 5 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV488 UT WOS:A1997XV48800008 ER PT J AU Peterson, JR AF Peterson, JR TI The American Chemical Society's Division of Nuclear Chemistry and Technology's summer schools in nuclear and radiochemistry SO JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY LA English DT Article; Proceedings Paper CT Symposium on Research and Education in Radioanalytical Chemistry, at the American-Chemical-Society Meeting CY MAR 24-26, 1996 CL NEW ORLEANS, LA SP Amer Chem Soc AB This successful educational pn,gram in nuclear and radiochemistry for advanced undergraduate students is described. Funding from the U.S. Department of Energy supports 24 fellowships for participants in the intensive six-week programs at San Jose State University (CA) and Brookhaven National Laboratory (NY). Students are provided transportation to and from the school site, room and board, books, lab supplies, and six units of college credit. The instructional program consists of lectures and laboratory exercises that cover the fundamentals of nuclear theory, radiochemistry, nuclear instrumentation, radiological safety, and applications in research, medicine, and industry. Guest lectures and field trips broaden the students' exposure to nuclear science. Assistance is provided in the following year to those students who wish to join a research project at a university or national laboratory, and thereafter, in their applications to graduate or professional school. C1 OAK RIDGE NATL LAB,TRANSURANIUM RES LAB,DIV CHEM & ANALYT SCI,OAK RIDGE,TN 37831. RP Peterson, JR (reprint author), UNIV TENNESSEE,DEPT CHEM,KNOXVILLE,TN 37996, USA. NR 3 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA LAUSANNE PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0236-5731 J9 J RADIOANAL NUCL CH JI J. Radioanal. Nucl. Chem. PD MAY PY 1997 VL 219 IS 2 BP 231 EP 236 DI 10.1007/BF02038505 PG 6 WC Chemistry, Analytical; Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA XV488 UT WOS:A1997XV48800013 ER PT J AU Anderson, DM AF Anderson, DM TI Practicing responsible tourism: International case studies in tourism planning, policy, and development - Harrison,LC, Husbands,W SO JOURNAL OF REGIONAL SCIENCE LA English DT Book Review RP Anderson, DM (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU BLACKWELL PUBLISHERS PI CAMBRIDGE PA 350 MAIN STREET, STE 6, CAMBRIDGE, MA 02148-5023 SN 0022-4146 J9 J REGIONAL SCI JI J. Reg. Sci. PD MAY PY 1997 VL 37 IS 2 BP 373 EP 374 PG 2 WC Economics; Environmental Studies; Planning & Development SC Business & Economics; Environmental Sciences & Ecology; Public Administration GA WY359 UT WOS:A1997WY35900020 ER PT J AU Carley, JF vonHoltz, E Flowers, GL AF Carley, JF vonHoltz, E Flowers, GL TI Flow of RX-08-FK high-energy paste in a capillary rheometer SO JOURNAL OF RHEOLOGY LA English DT Article ID RHEOLOGICAL BEHAVIOR; SUSPENSIONS AB The flow of RX-08-FK, a mostly organic, high-energy, paste-extrudable explosive containing about 75% suspended solids, was experimentally studied. The paste was forced through long capillary tubes in a specially designed, double-piston rheometer at temperatures ranging from -54 to +74 degrees C, and at nominal shear rates at the tube walls from 50 to 40000 s(-1) preconditioned for many hours to achieve the desired experimental temperature and the rheometer itself was enclosed in a preconditioned temperature-controlled chamber. We found the paste to be pseudoplastic with significant yield stress and entrance effects. The results of 176 runs at temperatures of -35 degrees C and higher were fitted by an empirical model much like the original model suggested by Herschel and Bulkey, modified to include a factor correcting the stress for the substantial entrance loss experienced with this paste. The observed stresses at -54 degrees C were substantially higher and less shear dependent than those extrapolated from the above model; these differences may relate to the fact that the glass-transition temperature of RX-08-FK is approximately -60 degrees C. (C) 1997 The Society of Rheology. C1 LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94551. MASON & HANGER SILAS MASON CO INC,PANTEX PLANT,AMARILLO,TX 79177. NR 19 TC 3 Z9 3 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD MAY-JUN PY 1997 VL 41 IS 3 BP 473 EP 489 DI 10.1122/1.550866 PG 17 WC Mechanics SC Mechanics GA WX638 UT WOS:A1997WX63800001 ER PT J AU Hampton, RE Mammoli, AA Graham, AL Tetlow, N Altobelli, SA AF Hampton, RE Mammoli, AA Graham, AL Tetlow, N Altobelli, SA TI Migration of particles undergoing pressure-driven flow in a circular conduit SO JOURNAL OF RHEOLOGY LA English DT Article ID CONCENTRATED SUSPENSIONS; COUETTE-FLOW; SPHERES; DIFFUSION AB This study focuses on the demixing of neutrally buoyant suspensions of spheres during slow, pressure driven Bows in circular conduits. Distributions of the solid fraction of particles, phi, and the suspension velocity, v, are measured at different lengths from a static in-line mixer. Experiments were conducted over a range of volume average solids fractions, phi(bulk) (0.10 less than or equal to phi less than or equal to 0.50), and at two different ratios of the particle radius, a, to the radius of the circular conduit, R (a/R = 0.0256 and a/R = 0.0625). At phi(bulk) greater than or equal to 0.20, the particles rapidly migrate to the low-shear-rate region in the center of the conduit. This migration results in a blunting of the v profile, relative to the parabolic profile observed in homogeneous Newtonian fluids. For the flow geometry with the smaller ratio of a/R, the phi profile builds to a sharp maximum or cusp in the center. Particle structures are observed in the experiments with the higher a/R. The entrance lengths for the development of the phi and v fields, L-phi and L-v, respectively, are strong functions of a/R and phi(bulk). L-phi and L-v rapidly decrease as phi and a/R increase. Over the range of our data, the v profiles are observed to develop more rapidly than the phi profiles. The experimental results are compared with fully developed flow predictions from the shear-induced migration (SIM) model and the suspension balance (SE) model. At the smaller a/R, the SIM model more accurately predicts the experimental results. At larger a/R, some qualitative features of the experimental results are better predicted by the SE model, however, neither model provides good quantitative predictions,especially at low phi(bulk). (C) 1997 The Society of Rheology. C1 LOS ALAMOS NATL LAB,LOS ALAMOS,NM 87545. LOVELACE INST,ALBUQUERQUE,NM 87108. NR 27 TC 142 Z9 143 U1 1 U2 28 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 SN 0148-6055 J9 J RHEOL JI J. Rheol. PD MAY-JUN PY 1997 VL 41 IS 3 BP 621 EP 640 DI 10.1122/1.550863 PG 20 WC Mechanics SC Mechanics GA WX638 UT WOS:A1997WX63800008 ER PT J AU Welker, KD Oman, PW Atkinson, GG AF Welker, KD Oman, PW Atkinson, GG TI Development and application of an automated source code maintainability index SO JOURNAL OF SOFTWARE MAINTENANCE-RESEARCH AND PRACTICE LA English DT Article DE software metrics; source code degradation; maintainability index; software quality assurance; reengineering; maintainability case studies ID SOFTWARE COMPLEXITY METRICS; PROGRAM MAINTENANCE AB When software maintenance results in changing the source code, the change frequently occurs in an undisciplined manner that results in source code that is inherently more difficult to maintain. The long-term effect may be thought of as a downward spiral that culminates in virtually 'unmaintainable' code where it is more cost effective to just start again. Too often, software personnel and managers, aware that the code is becoming less maintainable, have been unable to estimate with useful accuracy the degree to which maintainability has diminished. The result is that they either continue to waste time and money maintaining code which is effectively unmaintainable, or they opt to live with what seems to be bad code, not touching it for fear of breaking it. To avoid this state of affairs, software developers need to be able to quanitify both the current level of software maintainability and the impact on it of any given change. This paper discusses the application of software metrics as a tool for quantifying code maintainability and, by extension, for making decisions. The first part of the discussion focuses on deriving a minimal set of easily calculated metrics which, when taken together, can produce a single-valued quantification (or index) of code maintainability. Case studies are then presented which serve to illustrate not only the degree to which software can degrade over time, but how this 'maintainability index' (MI) can be used to quantify maintainability and aid decision making. Finally, a methodology for making metric assessments readily available to software personnel is presented so that they can now easily integrate maintainability metrics into maintenance (and development) processes. As a result, the downward spiral of code degradation becomes at least recognizable, hopefully less precipitous, and perhaps avoidable entirely. (C) 1997 by John Wiley & Sons, Ltd. C1 UNIV IDAHO, DEPT COMP SCI, MOSCOW, ID 83843 USA. RP LOCKHEED MARTIN IDAHO TECHNOL CO, POB 1625, IDAHO FALLS, ID 83415 USA. NR 41 TC 23 Z9 23 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLAND SN 1040-550X J9 J SOFTW MAINT-RES PR JI J. Softw. Maint.-Res. Pract. PD MAY-JUN PY 1997 VL 9 IS 3 BP 127 EP 159 DI 10.1002/(SICI)1096-908X(199705)9:3<127::AID-SMR149>3.0.CO;2-S PG 33 WC Computer Science, Software Engineering SC Computer Science GA XJ748 UT WOS:A1997XJ74800001 ER PT J AU Peercy, DE Chapin, N AF Peercy, DE Chapin, N TI Interview with David E. Peercy SO JOURNAL OF SOFTWARE MAINTENANCE-RESEARCH AND PRACTICE LA English DT Editorial Material DE risk assessment; risk management; software support; software logistics; software supportability; software maintenance ID SOFTWARE AB David E. Peercy summarizes and explains his more than 20 years of risk assessment work on software maintenance, including an analysis of more than 80 major systems. He places software maintenance in a larger context of software support and integrated logistic support, and describes the process of risk assessment, He contrasts his view of risk with common governmental, management and auditing views, and with the positions of others in the field, Drawing upon his findings and experience, he closes with four major insights about software maintenance, emphasizing the importance for an organization of having supportable software. (C) 1997 by John Wiley & Sons, Ltd. C1 INFOSCI INC,MENLO PK,CA 94026. RP Peercy, DE (reprint author), SANDIA NATL LABS,POB 5800,MS-0638,ALBUQUERQUE,NM 87185, USA. NR 31 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 1040-550X J9 J SOFTW MAINT-RES PR JI J. Softw. Maint.-Res. Pract. PD MAY-JUN PY 1997 VL 9 IS 3 BP 177 EP 200 PG 24 WC Computer Science, Software Engineering SC Computer Science GA XJ748 UT WOS:A1997XJ74800003 ER PT J AU Barnard, JC Wendell, LL AF Barnard, JC Wendell, LL TI A simple method of estimating wind turbine blade fatigue at potential wind turbine sites SO JOURNAL OF SOLAR ENERGY ENGINEERING-TRANSACTIONS OF THE ASME LA English DT Article AB This paper presents a technique of estimating blade fatigue damage at potential wind turbine sites. The cornerstone of this technique is a simple model for the blade's root flap bending moment. The model requires as input a simple set of wind measurements that may be obtained as part of a routine site characterization study. By using the model to simulate a time series of the root flap bending moment, fatigue damage rates may be estimated at the potential wind energy sites. The model is evaluated by comparing these estimates with damage estimates derived from actual bending moment data; the agreement between the two is good. Data from two different turbine types were used for the evaluation. For each type the model was tested at only one site because data from other sites were not available. To more firmly establish the universality of the model, further evaluation is necessary using the model applied to the same turbine located at different sites. RP Barnard, JC (reprint author), PACIFIC NW LAB, POB 999, RICHLAND, WA 99352 USA. NR 13 TC 1 Z9 1 U1 0 U2 2 PU ASME-AMER SOC MECHANICAL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 SN 0199-6231 J9 J SOL ENERG-T ASME JI J. Sol. Energy Eng. Trans.-ASME PD MAY PY 1997 VL 119 IS 2 BP 174 EP 186 DI 10.1115/1.2887900 PG 13 WC Energy & Fuels; Engineering, Mechanical SC Energy & Fuels; Engineering GA XA716 UT WOS:A1997XA71600014 ER PT J AU Mehta, A Berliner, R Smith, RW AF Mehta, A Berliner, R Smith, RW TI The structure of yttrium cobaltate from neutron diffraction SO JOURNAL OF SOLID STATE CHEMISTRY LA English DT Article ID PEROVSKITE AB The crystal structure of YCoO3 has been determined from Rietveld analysis of the powder neutron diffraction data at 17, 100, and 300 K. At each temperature, the structure is a distorted perovskite with orthorhombic symmetry, space group Pbnm (Z = 4). The lattice parameters, at 300 K, are 5.1388(5) x 5.4191(5) x 7.3658(7) Angstrom. Structural analysis indicates that the formal valence of cobalt in YCoO3 is +3. Analysis of the Co-O distances and the absence of magnetic structure indicates that the majority of the Co3+ ions in YCoO3 are in the low-spin (i.e. t(2g)(6)l(g)(0)) state. The data also show that perhaps 10% of the Co3+ ions at 300 K (but insignificant fractions at 100 and 17 K) are in the high-spin state. (C) 1997 Academic Press. C1 UNIV MISSOURI,RES REACTOR CTR,COLUMBIA,MO 65211. UNIV NEBRASKA,DEPT PHYS,OMAHA,NE 68182. RP Mehta, A (reprint author), STANFORD LINEAR ACCELERATOR CTR,STANFORD SYNCHROTRON RADIAT LAB,POB 4349,MS 69,STANFORD,CA 94309, USA. NR 14 TC 28 Z9 30 U1 2 U2 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0022-4596 J9 J SOLID STATE CHEM JI J. Solid State Chem. PD MAY PY 1997 VL 130 IS 2 BP 192 EP 198 DI 10.1006/jssc.1997.7279 PG 7 WC Chemistry, Inorganic & Nuclear; Chemistry, Physical SC Chemistry GA XL342 UT WOS:A1997XL34200004 ER PT J AU Baty, RS Vaughn, MR Farassat, F AF Baty, RS Vaughn, MR Farassat, F TI A nonstandard analysis of a simple discontinuous force equation modelling continuous motion SO JOURNAL OF SOUND AND VIBRATION LA English DT Letter C1 NASA,LANGLEY RES CTR,HAMPTON,VA 23665. RP Baty, RS (reprint author), SANDIA NATL LABS,POB 5800,ALBUQUERQUE,NM 87185, USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0022-460X J9 J SOUND VIB JI J. Sound Vibr. PD MAY 1 PY 1997 VL 202 IS 2 BP 288 EP 297 DI 10.1006/jsvi.1996.0740 PG 10 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA WX635 UT WOS:A1997WX63500010 ER PT J AU Cook, SR Hoffbauer, MA AF Cook, SR Hoffbauer, MA TI Nocilla model parameters obtained from forces exerted on surfaces by molecular beams SO JOURNAL OF SPACECRAFT AND ROCKETS LA English DT Article ID ACCOMMODATION COEFFICIENTS; HIGH-VACUUM; GAUGE AB The Nocilla gas-surface interaction model was used to approximate the velocity and angular distribution functions of H-2 and N-2 molecules scattered from surfaces of SiO2-coated Kapton(R) and Z-93-coated Al. A new formalism was developed to analyze the momentum transferred to surfaces by incident gases that is founded upon two parameters called the reduced force coefficients. The reduced force coefficients were experimentally determined from measurements of the forces exerted on the surfaces by molecular beams of the gases and used to calculate the Nocilla model parameters. RP Cook, SR (reprint author), LOS ALAMOS NATL LAB,POB 1663,LOS ALAMOS,NM 87545, USA. NR 23 TC 5 Z9 5 U1 0 U2 1 PU AMER INST AERONAUT ASTRONAUT PI RESTON PA 1801 ALEXANDER BELL DRIVE, STE 500, RESTON, VA 22091 SN 0022-4650 J9 J SPACECRAFT ROCKETS JI J. Spacecr. Rockets PD MAY-JUN PY 1997 VL 34 IS 3 BP 379 EP 383 DI 10.2514/2.3220 PG 5 WC Engineering, Aerospace SC Engineering GA XD627 UT WOS:A1997XD62700018 ER PT J AU Robidoux, N AF Robidoux, N TI Computer algebra and interpolation: A lesson plan SO JOURNAL OF SYMBOLIC COMPUTATION LA English DT Article AB Polynomial interpolation and related numerical analysis questions are used to take users of computer algebra systems from issuing one-liners to writing more complex programs. An alternate use of the outlined lessons is to introduce students to interpolation and acquaint them with splines and numerical differentiation. Constructive symbolic derivations of formulae for polynomial interpolants are presented. Numerical differentiation formulae are derived using them. Necessary background material is introduced. The examples and assignments can be done using any general purpose symbolic manipulator; complete codes using the computer algebra system AXIOM are given. (C) 1997 Academic Press Limited. C1 LOS ALAMOS NATL LAB,CTR NONLINEAR STUDIES,LOS ALAMOS,NM 87545. UNIV NEW MEXICO,DEPT MATH & STAT,ALBUQUERQUE,NM 87131. RP Robidoux, N (reprint author), UNIV NEW MEXICO,ALBUQUERQUE RESOURCE CTR HIGH PERFORMANCE COMP,EDUC & RES CTR,1601 CENT NE,ALBUQUERQUE,NM 87131, USA. NR 18 TC 0 Z9 0 U1 0 U2 0 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0747-7171 J9 J SYMB COMPUT JI J. Symb. Comput. PD MAY-JUN PY 1997 VL 23 IS 5-6 BP 551 EP 576 DI 10.1006/jsco.1996.0107 PG 26 WC Computer Science, Theory & Methods; Mathematics, Applied SC Computer Science; Mathematics GA XD470 UT WOS:A1997XD47000010 ER PT J AU Mills, DM AF Mills, DM TI X-ray optics developments at the APS for the third generation of high-energy synchrotron radiation sources SO JOURNAL OF SYNCHROTRON RADIATION LA English DT Article DE X-ray optics; high-heat-load optics; monochromators; phase-zone plates; polarization; meV resolution ID NUCLEAR BRAGG SCATTERING; HEAT LOADS; HIGH-POWER; MONOCHROMATOR; CRYSTAL; PERFORMANCE; RESOLUTION; SILICON AB Third-generation hard-X-ray synchrotron radiation sources simultaneously provide both a need and an opportunity for the development of new short-wavelength optical components. The high power and power densities of the insertion-device-produced X-ray beams have forced researchers to consider what may seem like exotic approaches, such as cryogenically cooled silicon and highly perfect diamond crystals, to mitigate thermal distortions in the first optical components. Once the power has been successfully filtered while maintaining the high beam brilliance, additional specialized optical components can be inserted into the monochromatic beam that take advantage of that brilliance. This paper reviews the performance of such optical components that have been designed, fabricated and tested at the Advanced Photon Source, starting with high-heat-load components and followed by examples of several specialized devices, such as an meV resolution (in-line) monochromator, a high-energy X-ray phase retarder and a phase-zone plate with submicrometer focusing capability. RP Mills, DM (reprint author), ARGONNE NATL LAB,ADV PHOTON SOURCE,9700 S CASS AVE,ARGONNE,IL 60439, USA. NR 27 TC 7 Z9 7 U1 0 U2 1 PU MUNKSGAARD INT PUBL LTD PI COPENHAGEN PA 35 NORRE SOGADE, PO BOX 2148, DK-1016 COPENHAGEN, DENMARK SN 0909-0495 J9 J SYNCHROTRON RADIAT JI J. Synchrot. Radiat. PD MAY 1 PY 1997 VL 4 BP 117 EP 124 DI 10.1107/S0909049596015889 PN 3 PG 8 WC Instruments & Instrumentation; Optics; Physics, Applied SC Instruments & Instrumentation; Optics; Physics GA XB662 UT WOS:A1997XB66200003 PM 16699217 ER PT J AU Petrovic, JJ Pena, MI Kung, HH AF Petrovic, JJ Pena, MI Kung, HH TI Fabrication and microstructures of MoSi2 reinforced Si3N4 matrix composites SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID SILICON-NITRIDE; MOLYBDENUM DISILICIDE; SINGLE-CRYSTALS; RESISTIVITY AB Details of the fabrication and microstructures of hot-pressed MoSi2 reinforced-Si3N4 matrix composites were investigated as a function of MoSi2 phase size and volume fraction, and amount of MgO densification aid. No reactions were observed between MoSi2, and Si3N4 at the fabrication temperature of 1750 degrees C. Composite microstructures varied from particle-matrix to cermet morphologies with increasing MoSi2 phase content. The MgO densification aid was present only in the Si3N4 phase. An amorphous glassy phase was observed at the MoSi2-Si3N4 phase boundaries, the extent of which decreased with decreased MgO level. No general microcracking was observed in the MoSi2-Si3N4 composites, despite the presence of a substantial thermal expansion mismatch between the MoSi2 and Si3N4 phases. The critical MoSi2 particle diameter for microcracking was calculated to be 3 mu m. MoSi2 particles as large as 20 mu m resulted in no composite microcracking; this indicated that significant stress relief occurred in these composites, probably because of plastic deformation of the MoSi2 phase. RP Petrovic, JJ (reprint author), LOS ALAMOS NATL LAB,DIV MAT SCI & TECHNOL,LOS ALAMOS,NM 87545, USA. NR 25 TC 37 Z9 38 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1997 VL 80 IS 5 BP 1111 EP 1116 PG 6 WC Materials Science, Ceramics SC Materials Science GA WZ554 UT WOS:A1997WZ55400008 ER PT J AU Brow, RK Tallant, DR Turner, GL AF Brow, RK Tallant, DR Turner, GL TI Polyhedral arrangements in lanthanum aluminoborate classes SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article ID BORATE GLASSES; SPECTROSCOPY; CRYSTALS; B-11 AB We have used magic-angle spinning nuclear magnetic resonance (MAS NMR) and Raman spectroscopy to examine the polyhedral arrangements in ternary lanthanum aluminoborate glasses. We have characterized two glass-forming series: chi Al2O3 .(l-chi)LaB3O6 and 0.25La(2)O(3) .gamma Al2O3 .(1-gamma)-B2O3. B-11 MAS NMR reveals a decrease in the fraction of four-coordinated boron atoms with increases in the Al2O3 content in both series. Al-27 MAS NMR has detected four-, five- and six-coordinated aluminum atoms in complex aluminoborate networks similar to those reported elsewhere for alkaline-earth aluminoborate glasses. Raman spectroscopy reveals a variety of borate and aluminoborate moieties, including isolated groups as well as methaborate chains and rings. These results indicate that the La3+ ion acts as a modifier to the aluminoborate network. C1 SPECTRAL DATA SERV, CHAMPAIGN, IL 61820 USA. RP Brow, RK (reprint author), SANDIA NATL LABS, POB 5800, ALBUQUERQUE, NM 87185 USA. NR 14 TC 56 Z9 59 U1 3 U2 18 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1997 VL 80 IS 5 BP 1239 EP 1244 PG 6 WC Materials Science, Ceramics SC Materials Science GA WZ554 UT WOS:A1997WZ55400025 ER PT J AU Unal, O Anderson, IE Maghsoodi, SI AF Unal, O Anderson, IE Maghsoodi, SI TI A test method to measure shear strength of ceramic joints at high temperatures SO JOURNAL OF THE AMERICAN CERAMIC SOCIETY LA English DT Article AB The asymmetrical four-point bend (AFPB) method, which provides a pure shear stress state in the middle of the test specimen, was utilized to measure the shear strength of the joints between Nicalon-fiber-reinforced SIC composites, The small test specimens were prepared as butt-joints with uniform depth (no notch), It was shown experimentally that the position of loading points is critical to induce shear fracture at the joint without the failure of base material, The appropriate positions for the present test specimen were determined and, as a result, an articulated ceramic fixture was designed, This test method is economical and involves small test specimens with simple geometry, and can be used at high temperatures. RP Unal, O (reprint author), US DOE,AMES LAB,AMES,IA 50011, USA. NR 6 TC 21 Z9 22 U1 2 U2 3 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7820 J9 J AM CERAM SOC JI J. Am. Ceram. Soc. PD MAY PY 1997 VL 80 IS 5 BP 1281 EP 1284 PG 4 WC Materials Science, Ceramics SC Materials Science GA WZ554 UT WOS:A1997WZ55400032 ER PT J AU Beaulieu, JC Saltveit, ME AF Beaulieu, JC Saltveit, ME TI Inhibition or promotion of tomato fruit ripening by acetaldehyde and ethanol is concentration dependent and varies with initial fruit maturity SO JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE LA English DT Article DE ACC oxidase; alcohol dehydrogenase; anaerobic pathway; ethylene; Lycopersicon esculentum; 4-methylpyrazole ID POST-HARVEST QUALITY; ALCOHOL-DEHYDROGENASE; ANAEROBIC CONDITIONS; PERICARP DISKS; CARBON-DIOXIDE; ETHYLENE; VAPORS; STRAWBERRIES; STORAGE AB 'Castlemart' tomato (Lycopersicon esculentum Mill.) pericarp discs were used to study the physiological effects of acetaldehyde and ethanol on fruit ripening. Short-term exposure of discs from mature-green fruit to acetaldehyde vapors on a fresh mass basis (less than or equal to 500 mu g.g(-1)) or ethanol vapors (less than or equal to 3 mg.g(-1)) promoted ripening, while higher concentrations inhibited ripening. Discs from mature-green fruit absorbed greater amounts of ethanol and produced significantly higher concentrations of acetaldehyde than discs from breaker fruit. Ripening was promoted by ethanol when the discs mere unable to retain or produce a certain level of acetaldehyde. Inhibition of ripening by 4 hours of exposure to ethanol (6 mg.g(-1)) was almost completely abolished by hypobaric treatments (18 kPa for 24 hours). However, acetaldehyde-induced ripening inhibition (2 days exposure to 180 mu g.g(-1)) was only slightly reduced by vacuum. Concentrations of acetaldehyde and ethanol that inhibited ripening reduced C2H4 production, whereas lower concentrations of acetaldehyde and ethanol that promoted ripening increased C2H4 production. Application of 4-methylpyrazole, an alcohol dehydrogenase inhibitor, enhanced acetaldehyde-induced ripening inhibition and reduced ethanol-induced ripening inhibition or promotion at all concentrations of acetaldehyde and ethanol tested. The inhibition of promotion of ripening of excised tomato pericarp discs by ethanol and acetaldehyde depended on initial fruit maturity, applied volatile concentration, and duration of exposure. C1 LAWRENCE LIVERMORE NATL LAB, DEPT VEGETABLE CROPS, MANN LAB, DAVIS, CA 95616 USA. OI Beaulieu, John/0000-0001-7767-5901 NR 39 TC 31 Z9 32 U1 0 U2 4 PU AMER SOC HORTICULTURAL SCIENCE PI ALEXANDRIA PA 701 NORTH SAINT ASAPH STREET, ALEXANDRIA, VA 22314-1998 SN 0003-1062 J9 J AM SOC HORTIC SCI JI J. Am. Soc. Hortic. Sci. PD MAY PY 1997 VL 122 IS 3 BP 392 EP 398 PG 7 WC Horticulture SC Agriculture GA WY388 UT WOS:A1997WY38800017 ER PT J AU TomasBarberan, FA LoaizaVelarde, J Bonfanti, A Saltveit, ME AF TomasBarberan, FA LoaizaVelarde, J Bonfanti, A Saltveit, ME TI Early wound- and ethylene-induced changes in phenylpropanoid metabolism in harvested lettuce SO JOURNAL OF THE AMERICAN SOCIETY FOR HORTICULTURAL SCIENCE LA English DT Article DE ethylene responses; Lactuca sativa; phenolic compounds; secondary metabolism; wound responses ID PHENYLALANINE AMMONIA-LYASE; ICEBERG LETTUCE; PHENOLIC METABOLISM; SHIKIMATE PATHWAY; RUSSET AB The phenolic composition of whole heads and excised midrib sections of iceberg, butter leaf, and romaine lettuce (Lactuca sativa L,) was followed at 5 and 10 degrees C during the first 3 days after wounding or during continuous exposure to 10 mu L.L-1 ethylene in air, After 3 days of storage at 5 and 10 degrees C, only 5-caffeoylquinic acid (chlorogenic acid), 3,5-dicaffeoylquinic acid (isochlorogenic acid), caffeoyltartaric acid, and dicaffeoyltartaric acid were detected in wounded lettuce midribs, Of these four compounds, chlorogenic acid accumulated to the highest level in all three lettuce types, The content of caffeic acid derivatives increased 3- and 6-fold after 72 hours of storage at 5 and 10 degrees C, respectively. The synthesis of caffeoyltartaric acid was not induced by wounding in iceberg lettuce, while chlorogenic acid increased 5-fold at 5 degrees C and 10-fold at 10 degrees C, Similar relative phenolic compositions were detected in the three lettuce types studied, although at different concentrations, Changes observed in the content of individual phenolic compounds during the first 3 days of ethylene exposure seemed to follow the same pattern observed during wound induction of the synthesis of phenolic compounds, Chlorogenic acid increased 5-fold and isochlorogenic acid increased 10-fold, while the content of caffeoyltartaric derivatives were not significantly altered by ethylene treatment, Isochlorogenic acid, which was only present in low amounts in the control, was synthesized in the later steps of wound and ethylene induction, Similar kinetics for the induction of phenolic compounds were observed in the three lettuce types studied, suggesting that the mechanisms by which wounding induces phenylpropanoid synthesis are common for the different lettuce types, C1 LAWRENCE LIVERMORE NATL LAB,DEPT VEGETABLE CROPS,MANN LAB,DAVIS,CA 95616. CEBAS,CSIC,E-30080 MURCIA,SPAIN. RI Tomas-Barberan, Francisco/D-6686-2011 OI Tomas-Barberan, Francisco/0000-0002-0790-1739 NR 14 TC 107 Z9 108 U1 1 U2 7 PU AMER SOC HORTICULTURAL SCIENCE PI ALEXANDRIA PA 701 NORTH SAINT ASAPH STREET, ALEXANDRIA, VA 22314-1998 SN 0003-1062 J9 J AM SOC HORTIC SCI JI J. Am. Soc. Hortic. Sci. PD MAY PY 1997 VL 122 IS 3 BP 399 EP 404 PG 6 WC Horticulture SC Agriculture GA WY388 UT WOS:A1997WY38800018 ER PT J AU Grimm, CC Clawson, R Short, RT AF Grimm, CC Clawson, R Short, RT TI Use of region II of the a/q stability diagram for fast scanning of a linear quadrupole mass spectrometer SO JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY LA English DT Article ID FILTER AB For evaluation as a detector for high-speed gas chromatography, a linear quadrupole mass spectrometer was operated in rf only mode by using Region II (a = 0; 7.514 < q < 7.580) of the Mathieu a/q stability diagram. The available power supply and the diameter of the quadrupole rods of the mass spectrometer placed an upper mass limit of similar to m/z 93. Scan rates of 1000 scans/s were obtained with mass spectral peaks resolved over an 80-u range. The m/z 91 and 92 ions produced from the electron ionization of toluene are resolved with an R-1/2 of 135. A potential difference between the source and the quadruple mass filter of up to 1000 V was used to accelerate ions into the quadrupole. Broadening of mass-to-charge ratio peaks results from the time constant of the signal amplification rather than the small number of rf cycles the ions experience. The expected loss of sensitivity relative to Region I is observed, and the problem of mass aliasing is discussed. (C) 1997 American Society for Mass Spectrometry. C1 OAK RIDGE NATL LAB,OAK RIDGE,TN. RP Grimm, CC (reprint author), USDA ARS,SO REG RES CTR,1100 ROBERT E LEE BLVD,NEW ORLEANS,LA 70124, USA. NR 15 TC 12 Z9 13 U1 0 U2 0 PU ELSEVIER SCIENCE INC PI NEW YORK PA 655 AVENUE OF THE AMERICAS, NEW YORK, NY 10010 SN 1044-0305 J9 J AM SOC MASS SPECTR JI J. Am. Soc. Mass Spectrom. PD MAY PY 1997 VL 8 IS 5 BP 539 EP 544 DI 10.1016/S1044-0305(97)00006-8 PG 6 WC Chemistry, Analytical; Chemistry, Physical; Spectroscopy SC Chemistry; Spectroscopy GA WV141 UT WOS:A1997WV14100008 ER EF