FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Anders, A Yushkov, G Oks, E Nikolaev, A Brown, I AF Anders, A Yushkov, G Oks, E Nikolaev, A Brown, I TI Ion charge state distributions of pulsed vacuum are plasmas in strong magnetic fields (abstract) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. State Univ Control Syst & Radioelect, Tomsk 634050, Russia. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Oks, Efim/A-9409-2014; Anders, Andre/B-8580-2009; Yushkov, Georgy/O-8024-2015; Nikolaev, Alexey/R-2154-2016 OI Oks, Efim/0000-0002-9323-0686; Anders, Andre/0000-0002-5313-6505; Yushkov, Georgy/0000-0002-7615-6058; Nikolaev, Alexey/0000-0003-2724-3697 NR 0 TC 1 Z9 1 U1 1 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 791 EP 791 DI 10.1063/1.1148737 PN 2 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600065 ER PT J AU Hershcovitch, A Johnson, BM Liu, F Anders, A Brown, IG AF Hershcovitch, A Johnson, BM Liu, F Anders, A Brown, IG TI Results from energetic electron beam metal vapor vacuum arc and Z-discharge plasma metal vapor vacuum arc: Development of new sources of intense high charge state heavy-ion beams SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB We are exploring a new approach for heavy-ion beam injection (e.g., into the relativistic heavy-ion collider at BNL), as well as new sources of intense high charge state ions to be mounted on a relatively low voltage platform for high energy ion implantation. While conventional metal vapor vacuum are (Mevva) ion sources can produce up to hundreds of milliamps or more of several-times-ionized metal ions (e.g., U3+), the recent results from Batalin et al. indicate that the addition of an energetic electron beam may lead to considerably higher charge states. An alternative way to produce the electron beam is where a Z-discharge plasma is used to enhance multiple ionization. As the vacuum are plasma plume expands into a magnetized drift region, a Z-discharge is triggered in the drifting metal plasma. The ions are then extracted and analyzed using a time-of-flight system. We report initial results using these schemes with applied discharge and electron beam voltages from 1 to 2 kV. (C) 1998 American Institute of Physics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Calif Berkeley, Berkeley, CA 94720 USA. RP Hershcovitch, A (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 18 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 798 EP 800 DI 10.1063/1.1148738 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600068 ER PT J AU MacGill, RA Dickinson, MR Anders, A Monteiro, OR Brown, IG AF MacGill, RA Dickinson, MR Anders, A Monteiro, OR Brown, IG TI Streaming metal plasma generation by vacuum arc plasma guns SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB We have developed several different embodiments of repetitively pulsed vacuum are metal plasma gun, including miniature versions, multicathode versions that can produce up to 18 different metal plasma species between which one can switch, and a compact high-duty cycle well-cooled version, as well as a larger de gun. Plasma guns of this kind can be incorporated into a vacuum are ion source for the production of high-energy metal ion beams, or used as a plasma source for thin film formation and for metal plasma immersion ion implantation and deposition. The source can also be viewed as a low-energy metal ion source with ion drift velocity in the range 20-200 eV depending on the metal species used. Here we describe the plasma sources that we have developed, the properties of the plasma generated, and summarize their performance and limitations. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP MacGill, RA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 12 TC 73 Z9 73 U1 1 U2 7 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 801 EP 803 DI 10.1063/1.1148718 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600069 ER PT J AU Liu, F Qi, N Gensler, S Prasad, RR Krishnan, M Brown, IG AF Liu, F Qi, N Gensler, S Prasad, RR Krishnan, M Brown, IG TI Vacuum arc ion source for heavy ion fusion SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID ACCELERATORS AB Heavy ion fusion is one approach to the problem of controlled thermonuclear power production, in which a small DT target is bombarded by an intense flux of heavy ions and compressed to fusion temperatures. There is a need in present HIF research and development for a reliable ion source for the production of heavy ion beams with low emittance, low beam noise, ion charge states Q=1+ to 3+, beam current -0.5 A, pulse width similar to 5-20 mu s, and repetition rate similar to 10 pulses per second. We have explored the suitability of a vacuum are ion source for this application. Energetic, high current, gadolinium ion beams were produced with parameters as required or close to those required. The performance parameters can all be improved yet further in an optimized ion source design. Here we describe the ion source configuration used, the experiments conducted, and the results obtained. We conclude that a vacuum are based metal ion source of this kind could be an excellent candidate for heavy ion fusion research application. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Alameda Appl Sci Corp, San Leandro, CA 94577 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Liu, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 13 TC 11 Z9 11 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 819 EP 821 DI 10.1063/1.1148467 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600075 ER PT J AU Hershcovitch, A AF Hershcovitch, A TI A plasma window for vacuum-atmosphere interface and focusing lens of sources for nonvacuum ion material modification (invited) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID ARC PLASMA AB Material modifications by ion implantation, dry etching, and microfabrication are widely used technologies, all of which are performed in vacuum, since ion beams at energies used in these applications are completely attenuated by foils or by long differentially pumped sections, which are currently used to interface between vacuum and atmosphere. A novel plasma window, which utilizes a short are for vacuum-atmosphere interface, has been developed. This window provides for sufficient vacuum atmosphere separation, as well as for ion beam propagation through it, thus facilitating nonvacuum ion material modification. (C) 1998 American Institute of Physics. C1 Brookhaven Natl Lab, AGS Dept, Upton, NY 11973 USA. RP Hershcovitch, A (reprint author), Brookhaven Natl Lab, AGS Dept, Upton, NY 11973 USA. NR 19 TC 9 Z9 9 U1 3 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 868 EP 873 DI 10.1063/1.1148468 PN 2 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600090 ER PT J AU Lee, Y Gough, RA Kunkel, WB Leung, KN Vujic, J Williams, MD Wutte, D Zahir, N AF Lee, Y Gough, RA Kunkel, WB Leung, KN Vujic, J Williams, MD Wutte, D Zahir, N TI Multicusp sources for ion beam projection lithography SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB Multicusp ion sources are capable of producing positive and negative ions with good beam quality and low energy spread. The ion energy spread of multicusp sources has been measured by three different techniques. The axial ion energy spread has been reduced by introducing a magnetic filter inside the multicusp source chamber which adjusts the plasma potential distribution. The axial energy spread is further reduced by optimizing the source configuration. Values as low as 0.8 eV have been achieved. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Tech Univ Vienna, Inst Allgemeine Phys, A-1060 Vienna, Austria. RP Lee, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 5 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 877 EP 879 DI 10.1063/1.1148469 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600092 ER PT J AU Anders, A MacGill, RA Brown, IG Vizir, A AF Anders, A MacGill, RA Brown, IG Vizir, A TI A filamentless ion source for materials processing SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID HOLLOW AB A dual-stage, multiaperture gas ion source with 5 cm beam diameter has been built and characterized. The first discharge stage is a constricted glow discharge injecting a plasma stream into a discharge cavity supporting a Penning ion gauge discharge in the low pressure mode. Both discharge stages and ion extraction are fed by a single, grounded power supply. This simplifies the electrical setup and reduces costs. Various gases have been tested including nitrogen, oxygen, and argon. The ion beam current density is 250 mu A/cm(2), i.e., the beam current is about 5 mA, at an extraction voltage of 3.0 kV and a discharge current of 59 mA. Measurements of the ion beam current as a function of various parameters such as the discharge voltage and current, gas flow, and magnetic field are presented. The source is compact and can be easily adapted to various materials modification applications in which ion energies of a few keV are required, (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Russian Acad Sci, Inst High Current Elect, Tomsk 634055, Russia. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009; Vizir, Alexey/R-2139-2016 OI Anders, Andre/0000-0002-5313-6505; Vizir, Alexey/0000-0002-9563-8650 NR 9 TC 6 Z9 6 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 880 EP 882 DI 10.1063/1.1148470 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600093 ER PT J AU Anders, A Kuhn, M AF Anders, A Kuhn, M TI Characterization of a low-energy constricted-plasma source (abstract) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Tech Univ, Inst Phys, D-09107 Chemnitz, Germany. RP Anders, A (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Anders, Andre/B-8580-2009 OI Anders, Andre/0000-0002-5313-6505 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 883 EP 883 DI 10.1063/1.1148741 PN 2 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600094 ER PT J AU Leung, KN AF Leung, KN TI Radio frequency driven multicusp sources (invited) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID ION-SOURCE; BEAMS AB The radio frequency (rf)-driven multicusp source was originally developed for use in the superconducting super collider injector. The source can routinely provide 30 mA of H-similar to beam at 0.1% duty factor. By adding a minute quantity of cesium to the discharge, H- beam current in excess of 100 mA and e/H similar to 1 has been achieved. The rf-driven H similar to source is being further developed for 6% duty factor operation to be used in the national spallation neutron source. Application of the rf-driven multicusp source has been extended to radioactive ion beam production, ion projection lithography, and compact neutron tubes. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Leung, KN (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,MS 5-119, Berkeley, CA 94720 USA. NR 13 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 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 998 EP 1002 DI 10.1063/1.1148705 PN 2 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600131 ER PT J AU Sherman, J Arvin, A Hansborough, L Hodgkins, D Meyer, E Schneider, JD Smith, HV Stettler, M Stevens, RR Thuot, M Zaugg, T Ferdinand, R AF Sherman, J Arvin, A Hansborough, L Hodgkins, D Meyer, E Schneider, JD Smith, HV Stettler, M Stevens, RR Thuot, M Zaugg, T Ferdinand, R TI Status report on a dc 130 mA, 75 keV proton injector (invited) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID EMITTANCE AB A 110 mA, 75 keV de proton injector is being developed at Los Alamos. A microwave proton source is coupled to a two solenoid, space-charge neutralized, low-energy beam transport (LEBT) system. The ion source produces 110 mA proton current at 75 keV using 600-800 W of 2.45 GHz discharge power. Typical proton fraction is 85%-90% of the total extracted ion current, and the rms normalized beam emittance after transport through a prototype 2.1 m LEBT is 0.20 (pi mm mrad). Beam space-charge neutralization is measured to be >98% which enables the solenoid magnetic transport to successfully match the injector beam into a radio-frequency quadrupole. Beam simulations indicate small emittance growth in the proposed 2.8 m low-energy demonstration accelerator LEBT. The LEBT also contains beam diagnostics, steering, and a beam deflector for variable duty factor and accelerator fast protect functions. The injector beam availability status is also discussed. (C) 1998 American Institute of Physics. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. CEA Saclay, LNS, F-91191 Gif Sur Yvette, France. RP Sherman, J (reprint author), Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 25 TC 38 Z9 41 U1 1 U2 1 PU AMER INST PHYSICS PI MELVILLE PA CIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1003 EP 1008 DI 10.1063/1.1148706 PN 2 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600132 ER PT J AU Sherman, J Arvin, A Hansborough, L Hodgkins, D Meyer, E Schneider, JD Stevens, RR Thuot, M Zaugg, T AF Sherman, J Arvin, A Hansborough, L Hodgkins, D Meyer, E Schneider, JD Stevens, RR Thuot, M Zaugg, T TI Development of a 130-mA, 75-kV high voltage column for high-intensity dc proton injectors SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB A reliable high-voltage (KV) column has been developed for de proton injectors with applications to high-intensity cw linacs. The HV column is coupled with a microwave-driven plasma generator to produce a 75-keV, 110-mA de proton beam. Typical proton fraction from this source is 85%-90%, requiring the HV column and accelerating electrodes to operate with a 130-mA hydrogen-ion beam current. A glow-discharge, which was caused by the ion source axial magnetic field, was initially observed in the HV column. This problem was solved by scaling the electron production processes, the magnetic field, and the HV column pressure into a favorable regime. A subsequent 168 h reliability run on the 75-keV injector showed that the ion source (plasma generator and HV column) has >98% beam availability. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Sherman, J (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 11 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 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1017 EP 1019 DI 10.1063/1.1148707 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600137 ER PT J AU Schmidt, CW Popovic, M AF Schmidt, CW Popovic, M TI Duoplasmatron source modifications for He-3(+) operation SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB A duoplasmatron ion source is used to produce 25 mA of He-3(+) with a pulse width of similar to 80 ms at 360 Hz for acceleration to 10.5 MeV. At this energy, He-3 striking water or carbon targets can produce short lived isotopes of C-11, N-13, O-15, and F-18 for medical positron emission tomography (PET). A duoplasmatron ion source was chosen originally since it is capable of a sufficient singly charged helium beam with an acceptable gas consumption. Stable long-term operation of the source required a change in the filament material to molybdenum, and a careful understanding of the oxide filament conditioning, operation and geometry. Other improvements, particularly in the electronics, were helpful to increasing the reliability. The source has operated for many months at similar to 2.5% duty factor without significant problems and with good stability. We report here the effort that was done to make this source understandable and reliable. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Schmidt, CW (reprint author), Fermi Natl Accelerator Lab, MS 307, Batavia, IL 60510 USA. NR 5 TC 2 Z9 2 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1020 EP 1022 DI 10.1063/1.1148746 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600138 ER PT J AU Lee, Y Gough, RA Leung, KN Perkins, LT Pickard, DS Vujic, J Wu, LK Olivo, M Einenkel, H AF Lee, Y Gough, RA Leung, KN Perkins, LT Pickard, DS Vujic, J Wu, LK Olivo, M Einenkel, H TI Quartz antenna for radio frequency ion source operation SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID HYDROGEN AB Radio-frequency (rf) driven multicusp ion sources developed at the Lawrence Berkeley National Laboratory use an internal induction coil (antenna) for plasma generation. The copper rf-antenna with a thin layer of porcelain coating, which is presently used, cannot fully satisfy the increasing demands on source cleanliness and antenna lifetime under high power cw or pulsed operation in applications where water cooling is not possible. A quartz antenna has been designed and operated in the multicusp ion source. It has been demonstrated that the overall performance of the new antenna exceeds that of the regular porcelain-coated antenna. It can be operated with a long lifetime in different discharge plasmas. The quartz antenna has also been tested at the Paul Scherrer Institute for cw source operation _at rf power higher than 5 kW. Results demonstrated that the antenna can survive under dense plasma discharge operations. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Univ Calif Berkeley, Dept Nucl Engn, Berkeley, CA 94720 USA. Stanford Univ, Dept Elect Engn, Stanford, CA 94305 USA. RP Lee, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 5 TC 5 Z9 5 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1023 EP 1025 DI 10.1063/1.1148708 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600139 ER PT J AU Alessi, JG AF Alessi, JG TI Report on the workshop on ion sources for hadron colliders (invited) SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB A workshop on Ion Sources for Hadron Colliders was held September 4-5, 1997 in Gelnhausen, Germany. This workshop, organized by the WE-Heraeus-Stiftung Foundation, the University of Frankfurt, Brookhaven National Laboratory, and CERN, directly followed the 7th Symposium on Electron Beam Ion Sources and Traps. Various options were reviewed for the development of a high current, intermediate charge state heavy ion source for use on colliders such as RHIC and LHC. In addition to status reports on electron cyclotron resonance, electron beam ion source, and laser sources, there was also discussion of issues relevant to the scaling of these sources to intensities as required by RHIC and LHC. The presentations and discussions from this workshop are summarized. (c) 1998 American Institute of Physics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Alessi, JG (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1040 EP 1044 DI 10.1063/1.1148709 PN 2 PG 5 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600143 ER PT J AU Perkins, LT Kwan, JW Leung, KN Rickard, M Williams, MD AF Perkins, LT Kwan, JW Leung, KN Rickard, M Williams, MD TI Ion source electrode biasing technique for microsecond beam pulse rise times SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB Heavy ion fusion (HIF) induction accelerators require ion sources that can deliver intense heavy ion beams with low emittance. The typical pulse length is 20 mu s with a rise time less than 1 mu s and a repetition rate of 10 Hz. So far, the surface ionization sources have been used in most HIF induction linac designs. However, there are other ions of interest to HIF (e.g., Hg, Xe, Rb, Ar, and Ne) which cannot be produced by the surface ionization sources, but rather by volume ion sources. In this paper, we describe an experiment that uses a multicusp source with a magnetic filter to produce beam pulses that have a rise time in the order of 1 mu s. By applying a positive biasing pulse on the plasma electrode with respect to the source body, the positive plasma ions can be temporarily repelled from the neighborhood of the extraction aperture, leading to a suppression of the ion beam. As the bias is removed, positive ions flow to the extraction region, enabling a fast-rising beam pulse. The beam current pulses show that there are two distinct groups of ions. An initial fast current rise time (< 2 mu s) corresponding to ions originating from within the magnetic filter region followed by a second group of ions with a longer rise time (10-20 mu s) originating from the plasma bulk region. Proper positioning of the filament cathode and the magnetic filter field relative to the extraction aperture was found to be critical. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Perkins, LT (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 2 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 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1060 EP 1062 DI 10.1063/1.1148710 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600150 ER PT J AU Barletta, WA Chu, WT Leung, KN AF Barletta, WA Chu, WT Leung, KN TI Ion sources for medical accelerators SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY ID MULTICUSP AB Advanced injector systems for proton synchrotrons and accelerator-based boron neutron capture therapy systems are being developed at the Lawrence Berkeley National Laboratory. Multicusp ion sources, particularly those driven by radio frequency, have been tested for these applications. The use of a radio frequency induction discharge provides clean, reliable, and long-life source operation. It has been demonstrated that the multicusp ion source can provide good-quality positive hydrogen ion beams with a monatomic ion fraction higher than 90%. The extractable ion current densities from this type of source can meet the injector requirements for both proton synchrotron and accelerator-based boron neutron capture therapy projects. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Barletta, WA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 8 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 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1085 EP 1087 DI 10.1063/1.1148712 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600159 ER PT J AU Whealton, JH Olsen, DK Raridon, RJ AF Whealton, JH Olsen, DK Raridon, RJ TI Toward a realistic and tractable model for negative-ion extraction from volume sources SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB A negative-ion source extraction model has been formulated and implemented that explicitly considers the motion of positive ions and the volume generation of negative ions. It is found that (1) for high-beam currents, the beam current is limited by a transverse space-charge limit, meaning that an increase in negative-ion density at the extraction sheath will result in a lower-beam current (this result is universally observed at high-beam current); (2) there is a saddle point with a potential barrier preventing most volume-produced negative ions from being extracted [the combination of (1) and (2) indicates that most of the negative ions being created do not find their way into the beam]; (3) the introduction of cesium may cause an increase in the transverse space-charge limit; (4) cesium also results in an increase in the fraction of volume-produced negative ions that are extracted; (5) cesium may also result in reduction of extracted electrons by producing a less negative bias on the plasma electrode with respect to the plasma, thus allowing the transverse space-charge limit budget to be taken up virtually totally by the ions. [The combination of (3)-(5) represents the way an actual increase in the beam current can be achieved]; (6) a strong ion time scale sheath instability due to violation of the Bohm criteria produces an anomalous ion temperature, which increases with the beam current, as routinely seen in measurements; and (7) the introduction of cesium may result in a reduction in this instability. These insights may lead to improvements in volume negative-ion sources. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Whealton, JH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 3 TC 8 Z9 8 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1103 EP 1105 DI 10.1063/1.1148749 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600164 ER PT J AU Anderson, OA Logan, BG AF Anderson, OA Logan, BG TI Beam extraction from a laser-driven multicharged ion source SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Anderson, OA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1106 EP 1106 DI 10.1063/1.1148872 PN 2 PG 1 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600165 ER PT J AU Becker, R Leung, KN Kunkel, W AF Becker, R Leung, KN Kunkel, W TI The virtual cathode: Key to the numerical simulation of negative ion extraction SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB The simulation of volume produced negative ions from a plasma is by far more complicated than the extraction of positive ions, while in experiments the only difficulty seemes to be connected with the power of the electrons, which are extracted at the same time. The reason for this complication in simple minded simulations is the infinite space charge, which builds up in the turning point of the positive ions in the extraction aperture for the negative ions. Smearing out the energy of the positive ions seems to help, however, this is mostly not justified by experiments, showing a low ion energy, especially in the region between the magnetic filter and the extraction hole. This difficulty may be overcome by using experience from virtual cathode formation in magnetically focused, decelerated electron beams. The decelerated electrons behave similarly to the reflected positive ions and are forming a virtual cathode in the reflection zone. From the analysis of the electron deceleration experiment, a simple power law is deduced to describe the decreasing electron current by the local potential. In turn, this power law may also be applied to the positive ion current, resulting in simulations without space charge singularity, even in the case of monoenergetic ions. Pis a first step towards the numerical simulation of negative ion extraction, a linear model has been made, using this power law. The transition from a Boltzmann distribution for the plasma electrons to a truncated one for the extracted beam electrons is considered as well, parallel to Langmuir's treatment of a thermal diode for electrons. (C) 1998 American Institute of Physics. C1 Univ Frankfurt, Inst Angew Phys, D-60054 Frankfurt, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Becker, R (reprint author), Univ Frankfurt, Inst Angew Phys, D-60054 Frankfurt, Germany. NR 4 TC 9 Z9 9 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1107 EP 1109 DI 10.1063/1.1148713 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600166 ER PT J AU Kponou, A Beebe, E Pikin, A Kuznetsov, G Batazova, M Tiunov, M AF Kponou, A Beebe, E Pikin, A Kuznetsov, G Batazova, M Tiunov, M TI Simulation of 10 A electron-beam formation and collection for a high current electron-beam ion source SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB Presented is a report on the development of an electron-beam ion source (EBIS) for the relativistic heavy ion collider at Brookhaven National Laboratory (BNL) which requires operating with a 10 A electron beam. This is approximately an order of magnitude higher current than in any existing EBIS device. A test stand is presently being designed and constructed where EBIS components will be tested. It will be reported in a separate paper at this conference. The design of the 10 A electron gun, drift tubes, and electron collector requires extensive computer simulations. Calculations have been performed at Novosibirsk and BNL using two different programs, SAM and EGUN. Results of these simulations will be presented. (C) 1998 American Institute of Physics. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Budker Inst Nucl Phys, Novosibirsk 630090, Russia. RP Kponou, A (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 4 TC 15 Z9 15 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1120 EP 1122 DI 10.1063/1.1148714 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600171 ER PT J AU Meyer, D Bolshukhin, D Wiesemann, K AF Meyer, D Bolshukhin, D Wiesemann, K TI Parametric decay of electron cyclotron waves and its influence on the ion transport in an electron cyclotron resonance ion source SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB When measuring the rf emission spectra of an electron cyclotron resonance plasma by a shielded antenna under different discharge conditions, a parametric decay of electron cyclotron waves was detected. Above a certain threshold of the launched microwave power, the pump wave at omega(0)/2 pi = 9.733 GHz decays into two different wave modes following the condition omega(2) = omega(0) +/- omega(1), where omega(1) is in the ion cyclotron resonance frequency range. Thus heating of ions is possible. Light ions are preferably heated. We consider this mechanism a possible candidate for explaining the isotope anomaly detected by A. Drentje et al. [Rev. Sci. Instrum. 67, 3 (1996)], which indicates that the heavier isotope of the same ion species is preferentially enriched in the discharge, whereas the Lighter one is more easily transported out of the plasma. Experimental results are discussed with respect to this hypothesis. (C) 1998 American Institute of Physics. C1 Ruhr Univ Bochum, D-44780 Bochum, Germany. RP Meyer, D (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 12 TC 7 Z9 7 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1126 EP 1128 DI 10.1063/1.1148715 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600173 ER PT J AU Goncharov, A Dobrovolsky, A Protsenko, I Kaluh, V Onishenko, I Brown, I AF Goncharov, A Dobrovolsky, A Protsenko, I Kaluh, V Onishenko, I Brown, I TI Some characteristics of moderate energy metal ion beam focusing by a high current plasma lens SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB The results of experiments on moderate energy (4-25 keV) metal ion beam focusing by a high current plasma lens (PL) are presented. The ion beam was produced by a two-chamber vacuum-are metal vapor vacuum are (MEVVA)-type ion source. Characteristics of the beam passing through the lens have been measured and the PL focusing properties determined fora wide range of ion beam energy and current. Distributions have been determined of the external potential along the lens electrodes that provide maximum increase of the beam current density on axis. Certain features of metal ion beam focusing by the PL are discussed. Some of these characteristics depend on the method of application of the external electric potential to the lens electrodes. (C) 1988 American. Institute of Physics. C1 NASU, Inst Phys, UA-252650 Kiev 39, Ukraine. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Goncharov, A (reprint author), NASU, Inst Phys, 46 Pr Nauki, UA-252650 Kiev 39, Ukraine. NR 7 TC 12 Z9 12 U1 0 U2 0 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0034-6748 EI 1089-7623 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1135 EP 1137 DI 10.1063/1.1148647 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600176 ER PT J AU Whealton, JH Raridon, RJ Leung, KN AF Whealton, JH Raridon, RJ Leung, KN TI Separation of beam and electrons in the spallation neutron source H- ion source SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB The spallation neutron source requires an ion source producing an H- beam with a peak current of 35 mA at a 6.2% duty factor. For the design of this ion source, extracted electrons must be transported and dumped without adversely affecting the H- beam optics. Two issues are considered: (1) electron containment transport and controlled removal; and (2) first-order H- beam steering. For electron containment, various magnetic, geometric, and electrode biasing configurations are analyzed. A kinetic description for the negative ions and electrons is employed with self-consistent fields obtained from a steady-state solution to Poisson's equation. Guiding center electron trajectories are used when the gyroradius is sufficiently small. The magnetic fields used to control the transport of the electrons and the asymmetric sheath produced by the gyrating electrons steer the ion beam. Scenarios for correcting this steering by split acceleration and focusing electrodes will be considered in some detail. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Lawrence Berkeley Lab, Berkeley, CA USA. RP Whealton, JH (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 2 TC 2 Z9 2 U1 0 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1158 EP 1160 DI 10.1063/1.1148716 PN 2 PG 3 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600184 ER PT J AU Sinclair, JW AF Sinclair, JW TI Software architecture considerations for ion source control systems SO REVIEW OF SCIENTIFIC INSTRUMENTS LA English DT Article; Proceedings Paper CT 7th International Conference on Ion Sources (ICIS 97) CY SEP 07-13, 1997 CL TAORMINA, ITALY AB General characteristics of distributed control system software tools are examined from the perspective of ion source control system requirements. Emphasis is placed on strategies for building extensible, distributed systems in which the ion source element is one component of a larger system. Vsystem, a commercial software tool kit from Vista Control Systems was utilized extensively in the control system upgrade of the Holifield Radioactive Ion Beam Facility. Part of the control system is described and the characteristics of Vsystem are examined and compared with those of the Experimental Physics and Industrial Control System (EPICS). (C) 1998 American Institute of Physics. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Sinclair, JW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 9 TC 0 Z9 0 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0034-6748 J9 REV SCI INSTRUM JI Rev. Sci. Instrum. PD FEB PY 1998 VL 69 IS 2 BP 1161 EP 1166 DI 10.1063/1.1148717 PN 2 PG 6 WC Instruments & Instrumentation; Physics, Applied SC Instruments & Instrumentation; Physics GA 104EW UT WOS:000075002600185 ER PT J AU Ortiz, ME Chavez-Lomeli, E Dacal, A Madani, H Suro, J del Campo, JG McConnell, J Shapira, D AF Ortiz, ME Chavez-Lomeli, E Dacal, A Madani, H Suro, J del Campo, JG McConnell, J Shapira, D TI Practical method to calibrate large arrays of detectors, the example of the HILI SO REVISTA MEXICANA DE FISICA LA English DT Article DE nuclear instrumentation; article detectors; sciltillators; heavy ions ID HEAVY-IONS; LIGHT AB Calibration of large arrays of detectors presents a non trivial problem, especially if non linear responses have to be dealt with, and a large variety of particle species is present. Based on a recent successful description of the light induced in scintillators by diferent ions, we propose an application to the practical case of the calibration of the HILI hodoscope array (192 phoswich detectors) for any particle. We are illustrating the method using alpha particles. C1 Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ortiz, ME (reprint author), Univ Nacl Autonoma Mexico, Inst Fis, Apartado Postal 20364, Mexico City 01000, DF, Mexico. NR 5 TC 0 Z9 0 U1 0 U2 0 PU SOCIEDAD MEXICANA DE FISICA PI COYOACAN PA APARTADO POSTAL 70-348, COYOACAN 04511, MEXICO SN 0035-001X J9 REV MEX FIS JI Rev. Mex. Fis. PD FEB PY 1998 VL 44 IS 1 BP 78 EP 81 PG 4 WC Physics, Multidisciplinary SC Physics GA YY578 UT WOS:000072162200012 ER PT J AU Suter, GW AF Suter, GW TI Comments on the interpretation of distributions in "overview of recent developments in ecological risk assessment" SO RISK ANALYSIS LA English DT Letter C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Suter, GW (reprint author), Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU PLENUM PUBL CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0272-4332 J9 RISK ANAL JI Risk Anal. PD FEB PY 1998 VL 18 IS 1 BP 3 EP 4 DI 10.1111/j.1539-6924.1998.tb00908.x PG 2 WC Public, Environmental & Occupational Health; Mathematics, Interdisciplinary Applications; Social Sciences, Mathematical Methods SC Public, Environmental & Occupational Health; Mathematics; Mathematical Methods In Social Sciences GA ZB065 UT WOS:000072431500002 ER PT J AU Shen, DZ Ren, GH Deng, Q Yin, ZW Woody, C Stoll, S AF Shen, DZ Ren, GH Deng, Q Yin, ZW Woody, C Stoll, S TI Scintillation properties of Gd doped beta-PbF2 crystal SO SCIENCE IN CHINA SERIES E-TECHNOLOGICAL SCIENCES LA English DT Article DE beta-PbF2 : Gd crystal; light output; decay time; emission spectrum ID LEAD FLUORIDE AB A single crystal sample of cubic lead chloride doped with gadolinium (beta-PbF2:Gd) was prepared by use of the Bridgman-Stockbarger method. The crystal samples for testing with dimension of empty set20 mm x 20 mm long were all polished. The dopant level of gadolinium is 0.15wt%. The light output and decay rime of the samples were measured in the lab using Cs-137 source and 1 GeV test beam at AGS respectively. Experimental results indicated that beta-PbF2:Gd crystal produces a weak scintillation emission at room temperature corresponding to a light output of similar to 6 photoelectrons per MeV and most of the light is collected within a gate of 30 ns. There is no evidence of any significant slow component extending out of 1 mu s In the X-ray excited emission spectra of beta-PbF2:Gd at room temperature, two emission peaks, 277 nm and 312 nm, were found and corresponded to the transition of I-6(J)-->S-8(7/2) and P-6(J)-->S-8(7/2) of Gd3+ ions, respectively. C1 Chinese Acad Sci, Shanghai Inst Ceram, Shanghai 201800, Peoples R China. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Shen, DZ (reprint author), Chinese Acad Sci, Shanghai Inst Ceram, Shanghai 201800, Peoples R China. NR 9 TC 1 Z9 1 U1 1 U2 5 PU SCIENCE PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 1006-9321 J9 SCI CHINA SER E JI Sci. China Ser. E-Technol. Sci. PD FEB PY 1998 VL 41 IS 1 BP 95 EP 100 DI 10.1007/BF02916878 PG 6 WC Engineering, Multidisciplinary; Materials Science, Multidisciplinary SC Engineering; Materials Science GA YT517 UT WOS:000071615000014 ER PT J AU Garcia, HE Houshyar, A AF Garcia, HE Houshyar, A TI Discrete event simulation of fuel transfer strategies for defueling a nuclear reactor SO SIMULATION LA English DT Article DE nuclear reactor; fuel transfer; Extend (TM); ProModel (TM) AB Fuel handling and conditioning activities for the decommissioning of the Experimental Breeder Reactor II are being performed at Argonne National Laboratory. Discrete event simulation and optimization techniques are being investigated to plan, supervise and perform these activities in such a way that productivity can be improved. The idea is to characterize this operation as a collection of interconnected sewing cells, and then apply operational research techniques to identify appropriate planning schedules for the given scenarios. This paper describes fat application of discrete event simulation to evaluate fuel transfer strategies and identify optimal solutions among distributed resources. C1 Argonne Natl Lab, Idaho Falls, ID 83401 USA. Western Michigan Univ, Dept Ind & Mfg Engn, Kalamazoo, MI 49008 USA. RP Garcia, HE (reprint author), Argonne Natl Lab, POB 2528, Idaho Falls, ID 83401 USA. NR 5 TC 4 Z9 4 U1 2 U2 2 PU SIMULATION COUNCILS INC PI SAN DIEGO PA PO BOX 17900, SAN DIEGO, CA 92117 USA SN 0037-5497 J9 SIMULATION JI Simulation PD FEB PY 1998 VL 70 IS 2 BP 104 EP 118 DI 10.1177/003754979807000203 PG 15 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA 160EU UT WOS:000078218100003 ER PT J AU Chopra, NG Zettl, A AF Chopra, NG Zettl, A TI Measurement of the elastic modulus of a multi-wall boron nitride nanotube SO SOLID STATE COMMUNICATIONS LA English DT Article ID TUBULES AB We have experimentally determined the elastic properties of an individual multi-wall boron nitride (BN) nanotube. From the thermal vibration amplitude of a cantilevered BN nanotube observed in a transmission electron microscope, we find the axial Young's modulus to be 1.22 +/- 0.24 TPa, a value consistent with theoretical estimates. The observed Young's modulus exceeds that of all other known insulating fibers. Our elasticity results confirm that BN nanotubes are highly crystalline with very few defects. (C) 1998 Elsevier Science Ltd. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Chopra, NG (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Zettl, Alex/O-4925-2016 OI Zettl, Alex/0000-0001-6330-136X NR 20 TC 373 Z9 388 U1 5 U2 36 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1998 VL 105 IS 5 BP 297 EP 300 DI 10.1016/S0038-1098(97)10125-9 PG 4 WC Physics, Condensed Matter SC Physics GA YU418 UT WOS:000071715100004 ER PT J AU von Behren, J van Buuren, T Zacharias, M Chimowitz, EH Fauchet, PM AF von Behren, J van Buuren, T Zacharias, M Chimowitz, EH Fauchet, PM TI Quantum confinement in nanoscale silicon: The correlation of size with bandgap and luminescence SO SOLID STATE COMMUNICATIONS LA English DT Article DE nanostructures; light absorption and reflection; luminescence ID POROUS SILICON; NANOCRYSTALS; FILMS; ABSORPTION; SPECTRA; SHAPE; DOTS AB The optical properties of silicon nanocrystallites of known sizes, present in supercritically dried porous silicon films of porosities as high as 92%, have been measured by a variety of techniques. The bandgap and luminescence energies have been measured as a function of size for the first time. The bandgap increases by more than 1 eV due to quantum confinement. The peak luminescence energy which also shifts to the blue is increasingly Stokes shifted with respect to the bandgap, as the size decreases. The measured bandgap is in agreement with realistic theories and the Stokes-shift between bandgap and luminescence energies coincides with the exciton binding energy predicted by these theories. These results demonstrate unambiguously and quantitatively the role of quantum confinement in the optical properties of this indirect gap semiconductor. (C) 1998 Elsevier Science Ltd. C1 Univ Rochester, Dept Elect Engn, Rochester, NY 14627 USA. Tech Univ Munich, D-85747 Garching, Germany. Lawrence Livermore Natl Lab, Dept Chem & Mat Sci, Livermore, CA 94556 USA. Otto Von Guericke Univ, D-39160 Magdeburg, Germany. Univ Rochester, Dept Chem Engn, Rochester, NY 14627 USA. Univ Rochester, Dept Phys & Astron, Laser Energet Lab, Rochester, NY 14627 USA. Univ Rochester, Inst Opt, Rochester, NY 14627 USA. RP von Behren, J (reprint author), Univ Rochester, Dept Elect Engn, Rochester, NY 14627 USA. RI Zacharias, Margit/A-5868-2011 OI Zacharias, Margit/0000-0002-2088-4929 NR 28 TC 113 Z9 113 U1 2 U2 16 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1998 VL 105 IS 5 BP 317 EP 322 DI 10.1016/S0038-1098(97)10099-0 PG 6 WC Physics, Condensed Matter SC Physics GA YU418 UT WOS:000071715100008 ER PT J AU Branz, HM AF Branz, HM TI Hydrogen collision model of light-induced metastability in hydrogenated amorphous silicon SO SOLID STATE COMMUNICATIONS LA English DT Article ID A-SI-H; DIFFUSION; DEFECTS AB A new model of light-induced metastability (Staebler-Wronski effect) in hydrogenated amorphous silicon is proposed. When two mobile H atoms generated by photo-induced carriers collide, they form a metastable, immobile complex containing two Si-H bonds. Excess metastable dangling bonds remain at the uncorrelated sites from which the colliding H were excited. The model accounts quantitatively for the kinetics of light-induced defect creation, both near room temperature and at 4.2 K. Other experimental results, including light-induced and thermal annealing kinetics, are also explained. (C) 1998 Elsevier Science Ltd. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Branz, HM (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. NR 31 TC 60 Z9 63 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1998 VL 105 IS 6 BP 387 EP 391 DI 10.1016/S0038-1098(97)10142-9 PG 5 WC Physics, Condensed Matter SC Physics GA YU443 UT WOS:000071717800007 ER PT J AU Isobe, T Weeks, RA Zuhr, RA AF Isobe, T Weeks, RA Zuhr, RA TI Magnetic properties of nanosize nickel particles produced in silica glasses by ion-implantation and subsequent annealing SO SOLID STATE COMMUNICATIONS LA English DT Article DE nanostructures, metals; nanofabrications; scanning and transmission electron microscopy; photoelectron spectroscopies ID METALS AB When Ni+ ions are implanted into silica glasses at a dose of 6 x 10(16) cm(-2) at 160 keV and 3 mu A cm(-2) nanosize Ni particles (6.5 +/- 1.5 nm) of spherical shape are produced in the implanted layer, as confirmed by transmission electron microscopy (TEM), electron diffractometry and X-ray photoelectron spectroscopy. The relative intensity of ferromagnetic resonance (FMR) absorption at 298 K increases by a factor of similar to 12 after annealing in 4%H-2 + 96%Ar for 4 h, although the Ni particle size observed by TEM does not change during this treatment. The mean Ni particle size, obtained from the temperature dependence of FMR intensity, increases from similar to 4.5 nm to similar to 5.5 nm by annealing. Magnetocrystalline anisotropy is observed in the FMR spectrum, measured at 133 K, of the annealed sample. The increase in FMR intensity by annealing is, therefore, attributed to an increase in the crystallinity of the Ni particles. (C) 1998 Elsevier Science Ltd. C1 Keio Univ, Fac Sci & Technol, Dept Appl Chem, Yokohama, Kanagawa 223, Japan. Vanderbilt Univ, Dept Appl & Engn Sci, Nashville, TN 37235 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Isobe, T (reprint author), Keio Univ, Fac Sci & Technol, Dept Appl Chem, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223, Japan. NR 16 TC 13 Z9 13 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0038-1098 J9 SOLID STATE COMMUN JI Solid State Commun. PD FEB PY 1998 VL 105 IS 7 BP 469 EP 472 DI 10.1016/S0038-1098(97)10156-9 PG 4 WC Physics, Condensed Matter SC Physics GA YV726 UT WOS:000071856600011 ER PT J AU Song, YQ Taylor, RE Pines, A AF Song, YQ Taylor, RE Pines, A TI Imaging of laser-polarized solid xenon SO SOLID STATE NUCLEAR MAGNETIC RESONANCE LA English DT Article DE laser-polarized xenon; magnetic resonance imaging; nuclear magnetic resonance spectroscopy ID XE-129; GAS AB The enhanced spin polarization produced by optical pumping of gaseous rubidium/xenon samples has made possible a number of recent experiments in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI). Here we report MRI of laser-polarized xenon in the solid phase at low temperature. Due to the high xenon density in the solid phase and the enhanced spin polarization, it is possible to achieve high intensity and spatial resolution of the image. Signals were observed from xenon films solidified onto the glass container walls and not from an enclosed chili pepper. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Song, YQ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. NR 16 TC 6 Z9 6 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0926-2040 J9 SOLID STATE NUCL MAG JI Solid State Nucl. Magn. Reson. PD FEB PY 1998 VL 10 IS 4 BP 247 EP 250 DI 10.1016/S0926-2040(97)00078-7 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical; Physics, Condensed Matter; Spectroscopy SC Chemistry; Physics; Spectroscopy GA ZH559 UT WOS:000073123500009 PM 9603626 ER PT J AU Rumsey, M Hurtado, J Hansche, B Simmermacher, T Carne, T Gross, E AF Rumsey, M Hurtado, J Hansche, B Simmermacher, T Carne, T Gross, E TI In-field monitoring of wind turbines SO SOUND AND VIBRATION LA English DT Article; Proceedings Paper CT 17th ASME Wind Energy Symposium CY JAN 12-15, 1998 CL RENO, NEVADA SP ASME AB Our primary goals in this work were to determine how well a laser Doppler vibrometer (LDV) could measure the structural dynamic response of a wind turbine that was parked in the field. We also wanted to determine if LDV modal information could be obtained from a naturally (wind) excited wind turbine. Our test results indicate the LDV can be successfully used in the field environment of an installed wind turbine but with a few restrictions, We were also successful in obtaining modal information from a naturally (wind) excited wind turbine in the field, but the data analysis requires a large number of averaged data sets to obtain reasonable results. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Univ Texas, El Paso, TX 79968 USA. RP Rumsey, M (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU ACOUSTICAL PUBL INC PI BAY VILLAGE PA 27101 E OVIATT RD PO BOX 40416, BAY VILLAGE, OH 44140 USA SN 0038-1810 J9 SOUND VIB JI Sound Vib. PD FEB PY 1998 VL 32 IS 2 BP 14 EP 19 PG 6 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA ZB348 UT WOS:000072462600004 ER PT J AU Ayers, CW AF Ayers, CW TI Electrical signature analysis for automotive alternator diagnostics SO SOUND AND VIBRATION LA English DT Article; Proceedings Paper CT 1996 Machinery Failure Prevention Technology Conference CY 1996 CL MOBILE, ALABAMA AB Automotive alternators are designed to supply power for automobile engine ignition systems as well as to charge the storage battery, The product is used in a large number of applications where consumers are concerned with acoustic noise and vibration that comes from the unit, as well as overall quality and dependability. Alternators and generators in general are used In industries other than automotive, for example: transportation and airline industries and also in military applications, Their manufacturers are interested in pursuing state-of-the-art methods to achieve higher quality and reduced costs. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ayers, CW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 4 Z9 4 U1 1 U2 2 PU ACOUSTICAL PUBL INC PI BAY VILLAGE PA 27101 E OVIATT RD PO BOX 40416, BAY VILLAGE, OH 44140 USA SN 0038-1810 J9 SOUND VIB JI Sound Vib. PD FEB PY 1998 VL 32 IS 2 BP 20 EP 25 PG 6 WC Acoustics; Engineering, Mechanical; Mechanics SC Acoustics; Engineering; Mechanics GA ZB348 UT WOS:000072462600005 ER PT J AU Lorenz, JC Billingsley, RL Evans, LW AF Lorenz, JC Billingsley, RL Evans, LW TI Permeability reduction by pyrobitumen, mineralization, and stress along large natural fractures in sandstones at 18,300-ft depth: Destruction of a reservoir SO SPE RESERVOIR EVALUATION & ENGINEERING LA English DT Article; Proceedings Paper CT 1996 SPE Annual Technical Conference and Exhibition CY OCT 06-09, 1996 CL DENVER, COLORADO SP Soc Petr Engineers AB Gas production from the Frontier formation at 18,300-ft depth in the Frewen Deep #4 well, eastern Green River basin (Wyoming), was uneconomic despite the presence of three sets of numerous, partially open, vertical natural fractures. Production dropped from 360 Mcf/D to 140 Mcf/D during a 10-day production test, and the well was abandoned. Examination of the fractures in the core suggests several possible reasons for this poor production. One factor is the presence of mineralization in the fractures. Another more important factor is that the remnant porosity left in the fractures by partial mineralization is commonly plugged with an overmature hydrocarbon residue (pyrobitumen). Reorientation of the in-situ horizontal compressive stress to a trend normal to the main fractures, which now acts to close fracture apertures during reservoir drawdown, is also an important factor. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Amoco Prod Co, Energy Grp N Amer, Denver, CO USA. RP Lorenz, JC (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 4 TC 2 Z9 3 U1 1 U2 4 PU SOC PETROLEUM ENG PI RICHARDSON PA 222 PALISADES CREEK DR,, RICHARDSON, TX 75080 USA SN 1094-6470 J9 SPE RESERV EVAL ENG JI SPE Reserv. Eval. Eng. PD FEB PY 1998 VL 1 IS 1 BP 52 EP 56 PG 5 WC Energy & Fuels; Engineering, Petroleum; Geosciences, Multidisciplinary SC Energy & Fuels; Engineering; Geology GA ZK931 UT WOS:000073378800009 ER PT J AU Trosset, MW Kafadar, K Morris, MD AF Trosset, MW Kafadar, K Morris, MD TI Queueing at the tax office - Comment SO STATISTICAL SCIENCE LA English DT Article ID ENGINEERS PHYSICAL SCIENTISTS; STATISTICIANS C1 Univ Arizona, Dept Math, Tucson, AZ 85721 USA. Univ Colorado, Dept Math, Denver, CO 80217 USA. Oak Ridge Natl Lab, Math Sci Sect, Oak Ridge, TN 37831 USA. RP Kafadar, K (reprint author), Univ Arizona, Dept Math, Tucson, AZ 85721 USA. NR 19 TC 2 Z9 2 U1 1 U2 1 PU INST MATHEMATICAL STATISTICS PI HAYWARD PA IMS BUSINESS OFFICE-SUITE 7, 3401 INVESTMENT BLVD, HAYWARD, CA 94545 USA SN 0883-4237 J9 STAT SCI JI Stat. Sci. PD FEB PY 1998 VL 13 IS 1 BP 23 EP 29 PG 7 WC Statistics & Probability SC Mathematics GA 101FM UT WOS:000074859000006 ER PT J AU Joyce, JJ Arko, AJ Cox, LE Czuchlewski, S AF Joyce, JJ Arko, AJ Cox, LE Czuchlewski, S TI Resonance photoelectron spectroscopy using a tunable laser plasma light source SO SURFACE AND INTERFACE ANALYSIS LA English DT Article; Proceedings Paper CT Surface Analysis 97 Symposium CY MAY 20-22, 1997 CL ALBUQUERQUE, NEW MEXICO SP Amer Vacuum Soc, Appl Surface Sci Div, Amer Vacuum Soc, New Mexico Chapter DE photoemission; laser; Pu; resonance ID ELECTRONIC-STRUCTURE; A-PU; PLUTONIUM; PHOTOEMISSION; SURFACE AB We report the first resonance photoemission experiments on plutonium metal, with surface preparation accomplished by means of laser ablation, The photoemission experiments were conducted using the newly commissioned tunable light source for transuranic research at Los Alamos. The light source is a tunable, laser plasma system capable of producing photons in the energy range 30-150 eV, with a photon flex of order 10(9) photons s(-1) at 0.1% bandwidth. First results on delta-phase plutonium reveal the 5d-5f resonance enhancement to be maximum at a photon energy of 113 eV. Lower energy photoemission results show a narrow peak very near the Fermi level, with a linewidth of order 100 meV. This peak is verified by resonance photoemission to be of 5f character bat also having strong 6d-7s contributions. The combination of high-energy resolution, tunable energies for orbital character determination and surface sensitivity of the UPS energy range make the laser plasma light source ideal for surface and interface studies. (C) 1998 John Wiley & Sons, Ltd. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Joyce, JJ (reprint author), Los Alamos Natl Lab, Mailstop K764, Los Alamos, NM 87545 USA. NR 19 TC 18 Z9 18 U1 0 U2 2 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD FEB PY 1998 VL 26 IS 2 BP 121 EP 123 DI 10.1002/(SICI)1096-9918(199802)26:2<121::AID-SIA352>3.3.CO;2-K PG 5 WC Chemistry, Physical SC Chemistry GA ZA745 UT WOS:000072396600006 ER PT J AU Stevenson, JO Ward, PP Smith, ML Markle, RJ AF Stevenson, JO Ward, PP Smith, ML Markle, RJ TI A plasma process monitor/control system SO SURFACE AND INTERFACE ANALYSIS LA English DT Article; Proceedings Paper CT Surface Analysis 97 Symposium CY MAY 20-22, 1997 CL ALBUQUERQUE, NEW MEXICO SP Amer Vacuum Soc, Appl Surface Sci Div, Amer Vacuum Soc, New Mexico Chapter DE plasma etching/processing; plasma diagnostics; optical emission spectroscopy; semiconductor plasma processing; thin film manufacturing processes ID OPTICAL-EMISSION SPECTROSCOPY AB Sandia National Laboratories has developed a system to monitor plasma processes for the control of industrial applications. The system is designed to act as a fully automated, stand-alone process monitor during printed wiring board and semiconductor production runs, The monitor routinely performs data collection, analysis, process identification and error detection/correction without the need for human intervention, The monitor can also be used in research mode to allow process engineers to gather additional information about plasma processes, Because plasma processes have wide application in thin-film growth, the monitor could also be used to better understand and control myriad thin-film manufacturing processes, Surface interactions, thin-him interfaces? growth and stoichiometry are potential areas of impact. The plasma process monitor/control system consists of a computer running software developed by Sandia National Laboratories, a commercially available spectrophotometer equipped with a charge-coupled de tice camera, an input/output device and a fiber-optic cable. The tool is designed to be a versatile, multipurpose piece of equipment allowing automated process verification and error detection/correction, as well as a research tool, We have used the monitor for gauging the 'state-of-health' of plasma processes, System 1 has been at Texas Instruments in Austin, TX, since February 1996, monitoring the health of printed wiring board plasma desmear and etch-back, System 2 has been at Advanced Micro Devices in Austin, TX, since July 1996, monitoring integrated circuit multivariate oxide etch, These systems and possible benefits derived from in situ monitoring of plasma processes will be discussed, (C) 1998 John Wiley & Sons, Ltd. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. Adv Micro Devices Inc, Austin, TX USA. RP Stevenson, JO (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 34 TC 18 Z9 18 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD FEB PY 1998 VL 26 IS 2 BP 124 EP 133 DI 10.1002/(SICI)1096-9918(199802)26:2<124::AID-SIA355>3.3.CO;2-2 PG 10 WC Chemistry, Physical SC Chemistry GA ZA745 UT WOS:000072396600007 ER PT J AU Taylor, TN Butt, DP Pantano, CG AF Taylor, TN Butt, DP Pantano, CG TI Auger parameter determination of bonding states on thinly oxidized silicon nitride SO SURFACE AND INTERFACE ANALYSIS LA English DT Article; Proceedings Paper CT Surface Analysis 97 Symposium CY MAY 20-22, 1997 CL ALBUQUERQUE, NEW MEXICO SP Amer Vacuum Soc, Appl Surface Sci Div, Amer Vacuum Soc, New Mexico Chapter DE Auger parameter; silicon nitride; x-ray photoelectron spectroscopy; XPS; Auger electron spectroscopy; AES; oxidation ID X-RAY PHOTOELECTRON; SURFACE OXIDATION-KINETICS; INDUCED AES; SPECTROSCOPY; POWDERS; SI3N4; FILMS AB Silicon nitride powders have been thermally oxidized between 700 and 1200 degrees C in a high-purity N-2-20% O-2 gas environment, The powders were subsequently analyzed by x-ray photoelectron and Anger electron spectroscopies for evidence of oxynitride surface states, Measurements were made on the Si 2p, O 1s, N 1s, C 1s, F 1s and Si KLL transitions, the latter being obtained using bremsstrahlung radiation from the Mg x-ray source, As a function of increasing temperature the data show a clear progression of spectral binding energies and peak shapes that are indicative of more advanced surface oxidation. However, definitive analysis of these data rests on the combined use of both Auger and photoelectron data to define the oxidized surface states for a system that involves two electrically insulating end states: silicon nitride and silicon dioxide, Curve fitting the Si 2p and Si I(LL transitions as a function of oxidation, coupled with tbe use of Auger parameters for the starting silicon nitride and final silicon dioxide, reveals no measurable evidence for an interphase oxynitride in the thin oxide scales of this study where the silicon nitride substrate is detectable. Possible incorrect assignment of oxynitride bonding, from shifted Si 2p states in the carbon referenced spectra, is attributable to band bending as the transition is made from incipient to fully formed silicon dioxide, (C) 1998 John Wiley & Sons, Ltd. C1 Univ Calif Los Alamos Natl Lab, Grp MST 6, Los Alamos, NM 87545 USA. Penn State Univ, Dept Mat Sci & Engn, University Pk, PA 16802 USA. RP Taylor, TN (reprint author), Univ Calif Los Alamos Natl Lab, Grp MST 6, MS-G755, Los Alamos, NM 87545 USA. RI Butt, Darryl/B-7480-2008 OI Butt, Darryl/0000-0003-4501-8864 NR 21 TC 9 Z9 9 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX PO19 1UD, ENGLAND SN 0142-2421 J9 SURF INTERFACE ANAL JI Surf. Interface Anal. PD FEB PY 1998 VL 26 IS 2 BP 134 EP 143 DI 10.1002/(SICI)1096-9918(199802)26:2<134::AID-SIA356>3.0.CO;2-7 PG 10 WC Chemistry, Physical SC Chemistry GA ZA745 UT WOS:000072396600008 ER PT J AU Chambers, SA Henderson, MA Kim, YJ Thevuthasan, S AF Chambers, SA Henderson, MA Kim, YJ Thevuthasan, S TI Chemisorption geometry, vibrational spectra, and thermal desorption of formic acid on TiO2(110) SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 5th International Conference on the Structure of Surfaces (ICS0S 5) CY JUL 08-12, 1996 CL UNIV D AIX MARSEILLE, AIX PROVENCE, FRANCE HO UNIV D AIX MARSEILLE ID SURFACE; DECOMPOSITION; HREELS; TPD AB We have used high-energy X-ray photoelectron spectroscopy and diffraction (XPS/XPD), low-energy electron diffraction (LEED), high-resolution electron energy loss spectroscopy (HREELS) and temperature-programmed desorption (TPD) to determine the molecular orientation, long-range order, vibrational frequencies, and desorption temperatures for formic acid and its decomposition products on TiO2(110). Molecular adsorption occurs at coverages approaching one monolayer, producing a weakly ordered (2 x 1) surface structure. High-energy XPD reveals that the formate binds rigidly in a bidentate fashion through the oxygens to Ti cation rows along the [001] direction with an O-C-O bond angle of 126 +/- 4 degrees. During TPD some surface protons and formate anions recombine and desorb as formic acid above 250 K. However, most of the decomposition products follow reaction pathways leading to H2O, CO and H2CO desorption. Water is formed in TPD below 500 K via the abstraction of lattice oxygen by deposited acid protons. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Chambers, SA (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999,MS K2-12, Richland, WA 99352 USA. NR 11 TC 25 Z9 25 U1 2 U2 19 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 FEB PY 1998 VL 5 IS 1 BP 381 EP 385 DI 10.1142/S0218625X98000700 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZL270 UT WOS:000073415800069 ER PT J AU Hirata, GA Mckittrick, J Devlin, D AF Hirata, GA Mckittrick, J Devlin, D TI Growth and analysis of red, green and blue luminescent oxide thin films SO SURFACE REVIEW AND LETTERS LA English DT Article; Proceedings Paper CT 5th International Conference on the Structure of Surfaces (ICS0S 5) CY JUL 08-12, 1996 CL UNIV D AIX MARSEILLE, AIX PROVENCE, FRANCE HO UNIV D AIX MARSEILLE ID ZNGA2O4 PHOSPHOR; CATHODOLUMINESCENT AB The growth and characterization of europium (Eu(3+)) and terbium (Tb(3+)) doped yttrium aluminum garnet (Y(3)Al(5)O(12) or YAG) and undoped ZnGa(2)O(4) photoluminescent thin films deposited on sapphire substrates at 400 degrees C by excimer pulsed laser ablation is reported. Smooth, continuous 500-nm-thick amorphous films were produced with compositions depleted in oxygen. Luminescence measurements on the as-deposited and on annealed samples revealed that heat treatments at temperatures > 800 degrees C were necessary to induce crystallization and reoxygenate, which coincided with the onset of luminescence. Annealing produced randomly oriented grains on the order of 15-200 nm. C1 Univ Nacl Autonoma Mexico, Ctr Ciencia Mat Condensada, Ensenada 22860, Baja California, Mexico. Univ Calif San Diego, Ames Dept, La Jolla, CA 92093 USA. Univ Calif San Diego, Mat Sci Program, La Jolla, CA 92093 USA. Los Alamos Natl Lab, MST Div, Los Alamos, NM 87545 USA. RP Hirata, GA (reprint author), Univ Nacl Autonoma Mexico, Ctr Ciencia Mat Condensada, Ensenada 22860, Baja California, Mexico. RI Hirata, Gustavo/E-2532-2016 NR 13 TC 3 Z9 3 U1 1 U2 10 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0218-625X J9 SURF REV LETT JI Surf. Rev. Lett. PD FEB PY 1998 VL 5 IS 1 BP 413 EP 417 DI 10.1142/S0218625X98000761 PG 5 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZL270 UT WOS:000073415800075 ER PT J AU Kidd, T Aburano, RD Hong, HW Gog, T Chiang, TC AF Kidd, T Aburano, RD Hong, HW Gog, T Chiang, TC TI Structural determination of the C-60/Ge(111) interface via X-ray diffraction SO SURFACE SCIENCE LA English DT Article DE carbon; coatings; germanium; single crystal epitaxy; surface relaxation and reconstruction; x-ray scattering, diffraction, and reflection ID SCANNING TUNNELING MICROSCOPY; CHARGE-TRANSFER; C-60 MOLECULES; SURFACE; SI(111)-(7X7); RECONSTRUCTION; ADATOMS AB An X-ray diffraction study was performed to determine the nature of the C-60/Ge(111) interface formed by depositing C-60 on a Ge(111)-c(2 x 8) surface at room temperature. In-plane k-scans show a (1 x 1) periodicity at the C-60/Ge(111) interface with no trace of the c(2 x 8) reconstruction, indicating that the Ce adatoms on the clean c(2 x 8)-reconstructed surface are displaced. Scans alone the (10) rod indicate that these adatoms are transferred from the T-4 bonding site to the H-3 site after C-60 deposition. A model consisting of three relaxed bilayers of Ge and randomly distributed adatoms in the H-3 site explains our results. (C) 1998 Elsevier Science B.V. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Frederick Seitz Mat Res Lab, Urbana, IL 61801 USA. Cypress Semicond, San Jose, CA 95134 USA. Argonne Natl Lab, Adv Photon Source, CMC CAT, Argonne, IL 60439 USA. RP Chiang, TC (reprint author), Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. EM t-chiang@uiuc.edu RI Chiang, Tai/H-5528-2011 NR 19 TC 10 Z9 10 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 FEB 1 PY 1998 VL 397 IS 1-3 BP 185 EP 190 DI 10.1016/S0039-6028(97)00731-0 PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZD031 UT WOS:000072643900024 ER PT J AU Eberhardt, A Fenter, P Eisenberger, P AF Eberhardt, A Fenter, P Eisenberger, P TI Growth kinetics in self-assembling monolayers: a unique adsorption mechanism SO SURFACE SCIENCE LA English DT Letter DE adsorption kinetics; alkanethiols; chemisorption; gold; mercaptans; self-assembly; X-ray scattering, diffraction, and reflection ID N-ALKYL THIOLS; GOLD SURFACES; AU(111); SPECTROSCOPY; SUPERLATTICE; ALKANETHIOLS; DISULFIDES; PHASES AB The adsorption kinetics of decanethiol (CH3(CH2)(9)SH) self-assembled from vapor on single crystal Au(111) surfaces have been investigated using grazing incidence X-ray diffraction. These in situ studies demonstrate the existence of two distinct adsorption mechanisms, including a unique associative mechanism in which the growth rate increases quadratically with the molecular impingement rate. These observations indicate that the self-assembly kinetics in these membrane-like films are more complex than previous studies have suggested. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Argonne Natl Lab, Argonne, IL 60439 USA. Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Columbia Earth Inst, New York, NY 10027 USA. RP Eberhardt, A (reprint author), Univ Calif Los Alamos Natl Lab, MS G-755, Los Alamos, NM 87545 USA. NR 25 TC 27 Z9 27 U1 4 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD FEB 1 PY 1998 VL 397 IS 1-3 BP L285 EP L290 DI 10.1016/S0039-6028(97)00873-X PG 6 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA ZD031 UT WOS:000072643900004 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 Measuring dopamine transporter occupancy by cocaine in vivo: Radiotracer considerations SO SYNAPSE LA English DT Article DE positron emission tomography (PET); [C-11]cocaine; [C-11]d-threo-methylphenidate; baboon ID POSITRON EMISSION TOMOGRAPHY; I-123 BETA-CIT; C-11 RACLOPRIDE; BABOON BRAIN; BINDING; PET; INVIVO; EQUIVALENT; LIGAND; SITES AB Several recent neuroimaging studies in humans and in monkeys using different radiotracers have reported widely differing values of dopamine transporter (DAT) occupancy by doses of cocaine which are perceived as reinforcing by humans. Here we tested the hypothesis that the measurement of DAT occupancies by drugs with fast pharmacokinetics such as cocaine requires a radioligand with similar kinetics in order to effectively compete with the drug. We measured DAT occupancy by four different doses of cocaine (1.0, 0.5, 0.25, and 0.1 mg/kg) using [C-11]d-threo-methylphenidate (a radiotracer which binds rapidly to the DAT in vivo) and compared them to estimates reported previously using [C-11]cocaine in the same two baboons and with the same four doses of cocaine [Volkow et al. (1996b) Synapse 24:399-402). Cocaine reduced [C-11]d-threo-methylphenidate binding in striatum in a dose-dependent manner, and values were significantly correlated with those obtained previously with [C-11]cocaine (r = 0.9, F = 37, P < 0.001). The ED(50)s (50% occupancy of DAT by cocaine) were 0.27 and 0.17 mg/kg for [C-11]d-threo-methylphenidate and [C-11]cocaine, respectively. This is significantly lower than values obtained with labeled beta-CIT and other similar radiotracers with a slow uptake and clearance (ED(50)s: 3-7 mg/kg). We conclude that in vivo measurements of DAT occupancy by rapidly clearing drugs like cocaine requires the use of radiotracers having similar kinetics to the drug itself. (C) 1998 Wiley-Liss, Inc. C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. SUNY Stony Brook, Dept Psychiat, Stony Brook, NY 11794 USA. RP Fowler, JS (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. FU NIDA NIH HHS [DA06278]; NINDS NIH HHS [NS 15638] NR 26 TC 53 Z9 53 U1 0 U2 1 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-4476 J9 SYNAPSE JI Synapse PD FEB PY 1998 VL 28 IS 2 BP 111 EP 116 DI 10.1002/(SICI)1098-2396(199802)28:2<111::AID-SYN1>3.0.CO;2-E PG 6 WC Neurosciences SC Neurosciences & Neurology GA YP320 UT WOS:000071265100001 PM 9450511 ER PT J AU Gifford, AN Gatley, SJ Volkow, ND AF Gifford, AN Gatley, SJ Volkow, ND TI Evaluation of the importance of rebinding to receptors in slowing the approach to equilibrium of high-affinity PET and SPECT radiotracers SO SYNAPSE LA English DT Article DE PET; SPECT; receptors; in vivo binding; SCH 23390; brain slice ID POSITRON EMISSION TOMOGRAPHY; RADIOLIGAND BINDING; KINETIC-ANALYSIS; H-3-SCH 23390; RAT STRIATUM; HUMAN BRAIN; DOPAMINE; INVIVO; SCH-23390; INFUSION AB The importance of rebinding to receptors in influencing the kinetics of in vivo binding of PET and SPECT radiotracers was evaluated by examining the binding of a high-affinity D-1 receptor radiotracer, [H-3]SCH 23390, in tissue homogenates, living brain slices, and in vivo. In rat striatal homogenates, [H-3]SCH 23390 binding reached equilibrium with a half-time of 6 min. By contrast, in striatal brain slices incubated in [H-3]SCH 23390, the radioactivity levels in the slice increased in a linear fashion over the 4-h incubation, with no indication of an approach to equilibrium at the termination of the experiment. In in vivo experiments, [H-3]SCH 23390 was given as a slow intravenous infusion to mice, using a paradigm that kept the plasma concentration at a constant level. Under these conditions, striatal [H-3]SCH 23390 levels increased in a linear fashion over the 4-h infusion period, similar to what was observed in the brain slices, and as in the slices there was no indication of approach to a steady state. However, when given instead as a single-bolus intravenous dose, the striatal [H-3]SCH 23390 levels reached a peak only 15 min after injection. Calculations based on the slice experiments, in which the blood-brain barrier is absent, suggested that the rate-limiting step accounting for the failure of [H-3]SCH 23390 levels to reach equilibrium was its hindered diffusion as a result of repeated rebinding to receptors. This phenomenon may also be important in vivo and should be considered as a factor in determining the time-course of binding of radiotracers in PET and SPECT experiments where either the receptor density or radiotracer affinity is high. (C) 1998 Wiley-Liss, Inc. C1 Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. RP Gifford, AN (reprint author), Brookhaven Natl Lab, Dept Med, Upton, NY 11973 USA. NR 25 TC 29 Z9 29 U1 0 U2 0 PU WILEY-LISS PI NEW YORK PA DIV JOHN WILEY & SONS INC, 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-4476 J9 SYNAPSE JI Synapse PD FEB PY 1998 VL 28 IS 2 BP 167 EP 175 DI 10.1002/(SICI)1098-2396(199802)28:2<167::AID-SYN7>3.0.CO;2-9 PG 9 WC Neurosciences SC Neurosciences & Neurology GA YP320 UT WOS:000071265100007 PM 9450517 ER PT J AU Yin, A Nie, S Craig, P Harrison, TM Ryerson, FJ Qian, XL Yang, G AF Yin, A Nie, S Craig, P Harrison, TM Ryerson, FJ Qian, XL Yang, G TI Late Cenozoic tectonic evolution of the southern Chinese Tian Shan SO TECTONICS LA English DT Article ID TIEN-SHAN; TIBETAN PLATEAU; CONTINENTAL COLLISION; SEDIMENTARY RECORD; AUTONOMOUS REGION; GRAVITY-ANOMALIES; NORTHWEST CHINA; CENTRAL-ASIA; TARIM BASIN; DEFORMATION AB Structural, sedimentological, magnetostratigraphic, and Ar-40/Ar-39 thermochronological investigations were conducted in the southern Chinese Tian Shan. On the basis of our own mapping and earlier investigations in the area, the Late Cenozoic southern Tian Shan thrust belt may be divided into four segments based on their style of deformation. From west to east, they are (1) Kashi-Aksu imbricate thrust system, (2) the Baicheng-Kuche fold and thrust system, (3) the Korla right-slip transfer system, and (4) the Lop-Nor thrust system. The westernmost Kashi-Aksu system is characterized by the occurrence of evenly spaced (12-15 km) imbricate thrusts. The Baicheng-Kuche and Korla systems are expressed by a major north dipping thrust (the Kuche thrust) that changes its strike eastward to become a NW striking oblique thrust ramp (the Korla transfer zone). The Lop Nor system in the easternmost part of the southern Chinese Tian Shan consists of widely spaced thrusts, all involved with basement rocks. Geologic mapping and cross-section construction suggest that at least 20-40 km of crustal shortening with a horizontal shortening strain of 20-30% has occurred in the southern Chinese Tian Shan during the late Cenozoic. These estimates are minimum because of both conservative extrapolation of the thrust geometries and partial coverage of the thrust belt by the cross sections. The timing of initial thrusting is best constrained in the Kuche basin where crustal shortening may have occurred at 21-24 Ma, the time of a major facies transition between lacustrine and braided-fluvial sequences constrained in general by biostratigraphy and in detail by magnetostratigraphy. This estimate represents only a minimum age, as development of thrusts in the southern Chinese Tian Shan may have propagated southward toward the foreland. Thus the sedimentary record only represents the southernmost and therefore youngest phase of thrusting. If our estimate of timing for the thrust initiation (21-24 Ma) is correct, using the estimated magnitude of shortening (20-40 km) and shortening strain (20-30%), the averaged rates of late Cenozoic horizontal slip and shortening strain are 1-1.9 mm yr(-1) and 2.9-4.5x10(-16) s(-1), respectively. Our reconnaissance Ar-40/Ar-39 thermochronological analysis in conjunction with earlier published results of apatite fission track analysis by other workers in the Chinese Tian Shan suggests that the magnitude of Cenozoic denudation is no more than 10 km, most likely less than 5 km. We demonstrate via a simple Airy-isostasy model that when the thermal effect on changes in surface elevation is negligible, determination of the spatial distribution and temporal variation of both horizontal shortening strain and denudation becomes a key to reconstructing the elevation history of the Tian Shan. Using this simple model, the loosely constrained magnitude of crustal-shortening strain and denudation in the southern Chinese Tian Shan implies that it may have been elevated 1.0-2.0 km since the onset of Cenozoic thrusting. C1 Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. Univ Calif Los Angeles, Inst Geophys & Planetary Phys, Los Angeles, CA 90095 USA. Peking Univ, Dept Geol, Beijing 100871, Peoples R China. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 95440 USA. RP Yin, A (reprint author), Univ Calif Los Angeles, Dept Earth & Space Sci, Los Angeles, CA 90095 USA. EM yin@ess.ucla.edu; shangyou.nie@petroconsultants.com; pcraig@shellus.com; ryerson1@popeye.llnl.gov RI Harrison, Timothy/E-7443-2012; Yin, An/B-3050-2014 NR 85 TC 254 Z9 413 U1 4 U2 40 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0278-7407 J9 TECTONICS JI Tectonics PD FEB PY 1998 VL 17 IS 1 BP 1 EP 27 DI 10.1029/97TC03140 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA YY396 UT WOS:000072142900001 ER PT J AU Jellison, GE AF Jellison, GE TI Spectroscopic ellipsometry data analysis: measured versus calculated quantities SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE generalized ellipsometry; ellipsometry calculations; anisotropic materials; mueller matrices; depolarization; parameterization of optical functions ID STRATIFIED ANISOTROPIC MEDIA; MOLECULAR-BEAM EPITAXY; OPTICAL-PROPERTIES; MATRIX-METHOD; THIN-FILMS; DIELECTRIC FUNCTION; AMORPHOUS MATERIALS; MUELLER MATRIX; CONSTRAINTS; ALXGA1-XAS AB Spectroscopic ellipsometry is a very powerful technique for optical characterization of thin-film and bulk materials, but the technique measures functions of complex reflection coefficients, which are usually not of interest per se. The interesting characteristics, such as film thickness, surface roughness thickness and optical functions can be determined only by modeling the near-surface region of the sample. However, the measured quantities are not equivalent to those determined from the modeling. Ellipsometry measurements determine elements of the sample Mueller matrix, but the usual result of modeling calculations are elements of the sample Jones matrix. Often this difference is academic, bur if the sample depolarizes the light, it is not. Ellipsometry calculations also include methods for determining the optical functions of materials. Data for bulk materials are usually accurate for substrates, but are not appropriate for most thin films. Therefore, reasonable parameterizations are quite useful in pet-forming spectroscopic ellipsometry data analysis. Recently, there has been an increased interest in anisotropic materials, both in thin-film and bulk form. A generalized procedure will be presented for calculating the elements of the Jones matrix for any number of layers, any one of which may or may not be uniaxial. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Jellison, GE (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. EM jellisongejr@ornl.gov NR 53 TC 236 Z9 237 U1 11 U2 55 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 33 EP 39 PG 7 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700005 ER PT J AU Junge, KE Voss, NR Lange, R Dolan, JM Zollner, S Dashiell, M Hits, DA Orner, BA Jonczyk, R Kolodzey, J AF Junge, KE Voss, NR Lange, R Dolan, JM Zollner, S Dashiell, M Hits, DA Orner, BA Jonczyk, R Kolodzey, J TI Optical properties and band structure of Ge1-yCy and Ge-rich Si1-x-yGexCy alloys SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE optical properties; dielectric function; germanium; carbon ID MOLECULAR-BEAM EPITAXY; SPECTROSCOPIC ELLIPSOMETRY; STRAINED SI1-YCY; SEMICONDUCTOR ALLOYS; DIELECTRIC FUNCTION; SI(001); TRANSITIONS; LAYERS; SI; PARAMETERS AB We measured the dielectric function of Ge1-yCy and Ge-rich Si1-x-yGexCy alloys from 1.6 to 5.2 eV using spectroscopic ellipsometry. These alloys were grown by molecular beam epitaxy at 600 degrees C on (001) Si substrates. Analytic lineshapes fitted to numerically calculated derivatives of their dielectric functions determined the critical-point parameters of the E-1, E-1 + Delta(1), E-0', and E-2 transitions. The critical-point energies of the Ge1-yCy alloys were found to be indistinguishable from those of bulk Ge. This indicates that the presence of C in these alloys has no detectable influence on the band structure. The amplitude of the ellipsometric spectra is much lower than for bulk Ge, which can be attributed to surface roughness and explained within the framework of the Kirchhoff theory of diffraction or using effective medium theory. The degree of surface roughness indicated by optical measurements was verified by atomic force microscopy. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Delaware, Dept Elect & Comp Sci, Newark, DE 19716 USA. RP Zollner, S (reprint author), SPS, Arizona Technol Labs, MD M360,2200 W Broadway Rd, Mesa, AZ 85202 USA. RI Zollner, Stefan/B-4858-2012; Voss, Neil/K-6244-2012 OI Zollner, Stefan/0000-0001-7752-7941; NR 29 TC 1 Z9 1 U1 0 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 172 EP 176 DI 10.1016/S0040-6090(97)00806-7 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700030 ER PT J AU Jellison, GE Modine, FA Doshi, P Rohatgi, A AF Jellison, GE Modine, FA Doshi, P Rohatgi, A TI Spectroscopic ellipsometry characterization of thin-film silicon nitride SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE silicon nitride; spectroscopic ellipsometry; amorphous materials; Tauc-Lorentz; anti-reflection coatings ID OPTICAL FUNCTIONS; DIELECTRICS; HYDROGEN AB We have measured and analyzed the optical characteristics of a series of silicon nitride thin films prepared by plasma-enhanced chemical vapor deposition on silicon substrates for photovoltaic applications. Spectroscopic ellipsometry measurements were made by using a two-channel spectroscopic polarization modulator ellipsometer that measures N, S, and C data simultaneously. The data were fit to a model consisting of air/roughness/SiN/crystalline silicon. The roughness was modeled using the Bruggeman effective medium approximation, assuming 50% SiN, 50% voids. The optical functions of the SiN film were parameterized using a model by Jellison and Modine (Appl. Phys. Lett. 69 (1996) 371; 69 (1996) 2137). All the chi(2) are near 1, demonstrating that this model works extremely well for all SIN films. The measured dielectric functions were used to make optimized SIN anti-reflection coatings for crystalline silicon solar cells. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Georgia Inst Technol, Sch Elect & Comp Engn, Atlanta, GA 30332 USA. RP Jellison, GE (reprint author), Oak Ridge Natl Lab, Div Solid State, POB 2008, Oak Ridge, TN 37831 USA. NR 16 TC 60 Z9 60 U1 0 U2 18 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 193 EP 197 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700034 ER PT J AU Lee, SJ Lange, RJ Hong, S Zollner, S Canfield, PC Panchula, AF Harmon, BN Lynch, DW AF Lee, SJ Lange, RJ Hong, S Zollner, S Canfield, PC Panchula, AF Harmon, BN Lynch, DW TI Theoretical and experimental determination of optical and magneto-optical properties of LuFe2 single crystal SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE Kerr effect; LuFe2; rare earth compounds; optical conductivity; TB-LMTO ID DEPENDENCE; METALS; LU AB We have studied the diagonal and off-diagonal optical conductivity of a LuFe2 single crystal grown by the flux method. Using spectroscopic ellipsometry we have measured the dielectric function from 1.5 to 5.5 eV. The magneto-optical parameters (Kerr rotation and ellipticity) from 1.4 to 4.0 eV were obtained using a magneto-optical polar Kerr spectrometer at temperatures between 7 and 295 K and applied magnetic fields up to 1.2 T which fully saturates the magnetic moment of LuFe2. We describe the apparatus and evaluate the off-diagonal conductivity components from the data. Theoretical calculations of optical conductivities and magneto-optical parameters were performed using the tight binding-linear muffin tin orbitals method within the local spin density approximation. When lifetime broadening is included, the calculations agree well with the experimental data. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. RP Lange, RJ (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. EM lange@ameslab.gov RI Zollner, Stefan/B-4858-2012; Canfield, Paul/H-2698-2014 OI Zollner, Stefan/0000-0001-7752-7941; NR 22 TC 5 Z9 5 U1 0 U2 0 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 222 EP 227 DI 10.1016/S0040-6090(97)00822-5 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700040 ER PT J AU Yao, H Erickson, JC Lim, LA James, RB AF Yao, H Erickson, JC Lim, LA James, RB TI Anisotropic dielectric response and surface aging of mercuric iodide crystal studied by variable angle spectroscopic ellipsometry SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE ellipsometry; mercuric iodide; anisotropic dielectric functions; surface aging ID OPTICAL-PROPERTIES; HGI2 AB Variable angle spectroscopic ellipsometry (VASE) was employed to study the anisotropic optical properties and surface aging phenomena of mercuric iodide (HgI2) - a material for room-temperature radiation detectors. In the optical property study, two surface orientations of this tetragonal crystal were selected, i.e. an a-plane and a c-plane sample. Room temperature multiple-angle SE measurements from both samples with three different optical configurations along with polarized transmission measurements were analyzed simultaneously by the VASE analysis through multiple-sample, multiple-model methods. Anisotropic dielectric functions of single crystal HgI2, epsilon(perpendicular to)(omega) and epsilon(parallel to)(omega), for optical electric field vectors oriented perpendicular and parallel to the c axis, respectively, were obtained over the range of 1.24-5.1 eV. In the surface aging characterization, three different initial HgI2 surface conditions were selected, i.e. an as-grown surface, a cleaved surface, and a surface chemically etched by 10% KI solution. A model of the HgI2 crystal including top surface roughness and subsurface defects was established and characterized, as a function of time, by the VASE analysis. In this model, the surface defects associated with the surface aging were modeled by the Bruggeman effective-medium approximation (EMA) as a HgI2/void mixed overlayer. The relative 2-dimensional (2D) surface-defect-densities were then monitored as the surface aging proceeded. (C) 1998 Elsevier Science S.A. C1 Univ Nebraska, Ctr Microelect & Opt Mat Res, Dept Elect Engn, Lincoln, NE 68588 USA. Sandia Natl Labs, Livermore, CA 94551 USA. RP Yao, H (reprint author), Univ Nebraska, Ctr Microelect & Opt Mat Res, Dept Elect Engn, Lincoln, NE 68588 USA. NR 16 TC 7 Z9 7 U1 1 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 351 EP 355 DI 10.1016/S0040-6090(97)00845-6 PG 5 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700063 ER PT J AU Michaelis, A Irene, EA Auciello, O Krauss, AR Veal, B AF Michaelis, A Irene, EA Auciello, O Krauss, AR Veal, B TI A spectroscopic anisotropy ellipsometry study of YBa2Cu3O7-x superconductors SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE anisotropy; YBa2Cu3O7-x; spectroscopic anisotropy micro-ellipsometry (SAME) ID THIN-FILMS; OXYGEN AB The effect of the optical anisotropy of the high temperature superconducting compound YB2Cu3O7-x (YBCO) on spectroscopic ellipsometry (SE) measurements was studied. For this, the method of spectroscopic anisotropy micro-ellipsometry (SAME) was employed on c-axis- as well as on a,b-axes-oriented YBCO single crystals. SAME measures the ellipsometric parameters Delta and Psi as a function of the angle alpha which describes sample rotation around the surface normal. The analysis of the resulting Delta(alpha) and Psi(alpha)-curves yielded the ordinary and averaged extraordinary complex refractive indices in the UV-VIS range. Additionally, the crystallographic orientation angle phi between the optical axis and the surface normal could be determined. The single crystal results were applied to SE measurements performed on differently oriented YBCO thin films which were prepared by ion beam sputter deposition on top of (100) SrTiO3 substrates. It is shown that SE allows for in-situ monitoring of the crystallographic orientation of thin YBCO films. (C) 1998 Elsevier Science S.A. C1 Univ N Carolina, Dept Chem, Chapel Hill, NC 27599 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Michaelis, A (reprint author), IBM, Siemens Microelect, 1580 Rte 52 Zip 33A,Bldg 630,Hopewell Jct, New York, NY 12533 USA. EM v2mich@us.ibm.com RI Michaelis, Alexander/R-9240-2016 OI Michaelis, Alexander/0000-0002-5987-1252 NR 15 TC 7 Z9 7 U1 0 U2 19 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 362 EP 367 DI 10.1016/S0040-6090(97)00847-X PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700065 ER PT J AU Zollner, S Myers, KD Dolan, JM Bailey, DW Stanton, CJ AF Zollner, S Myers, KD Dolan, JM Bailey, DW Stanton, CJ TI Theory of femtosecond ellipsometry in Ge at 1.5 eV SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE ellipsometry; femtosecond laser pulses; germanium ID ULTRAFAST THERMALIZATION; NONEQUILIBRIUM HOLES; WANNIER EXCITONS; GERMANIUM; GAAS; SEMICONDUCTORS; SPECTROSCOPY; TRANSMISSION; KINETICS; PHONON AB Intense photoexcitation of a semiconductor using femtosecond laser pulses affects its optical properties. We consider the transient photoinduced changes Delta epsilon to the dielectric function epsilon of bulk Ge after excitation with 100-fs laser pulses at 1.5 eV creating a carrier density of 4 x 10(18) cm(-3) due to three mechanisms: (i) diffusion of carriers from the surface into the bulk, (ii) relaxation of carriers in momentum space, and (iii) many-body effects, including band gap renormalization, collisional broadening, screening of the excitonic Coulomb enhancement, and band filling. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys & Astron, Ames, IA 50011 USA. Univ S Carolina, Dept Elect & Comp Engn, Columbia, SC 29208 USA. Univ Florida, Dept Phys, Gainesville, FL 32611 USA. RP Zollner, S (reprint author), Motorola SPS, Technol Lab, MD M360,2200 W Broadway Rd, Mesa, AZ 85202 USA. RI Zollner, Stefan/B-4858-2012 OI Zollner, Stefan/0000-0001-7752-7941 NR 25 TC 8 Z9 8 U1 1 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 FEB PY 1998 VL 313 BP 568 EP 573 DI 10.1016/S0040-6090(97)00886-9 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700103 ER PT J AU Kong, FP Kostecki, R McLarnon, F Muller, RH AF Kong, FP Kostecki, R McLarnon, F Muller, RH TI Spectroscopic ellipsometry of electrochemical precipitation and oxidation of nickel hydroxide films SO THIN SOLID FILMS LA English DT Article; Proceedings Paper CT 2nd International Conference on Spectroscopic Ellipsometry (ICSE-2) CY MAY 12-15, 1997 CL CHARLESTON, SOUTH CAROLINA DE spectroscopic ellipsometry; nickel hydroxide; electrochemical precipitation; inhomogeneous films; effective medium approximation ID DIFFUSION-COEFFICIENT; PROTON DIFFUSION; DEPOSITION; BETA-NI(OH)(2) AB In situ spectroscopic ellipsometry was used to investigate the electrochemical precipitation of nickel hydroxide films. By use of optical models for inhomogeneous films it was found that a specific precipitation current density produced the most compact and homogeneous film structures. The density of nickel hydroxide films was derived to be 1.25-1.50 g/cm(3). The redox behavior of precipitated nickel hydroxide films was studied with an effective-medium optical model. Incomplete conversion to nickel oxyhydroxide and a reduction in film thickness were found during the oxidation cycle. Published by Elsevier Science S.A. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Kong, FP (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. NR 16 TC 13 Z9 15 U1 2 U2 4 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0040-6090 J9 THIN SOLID FILMS JI Thin Solid Films PD FEB PY 1998 VL 313 BP 775 EP 780 DI 10.1016/S0040-6090(97)00994-2 PG 6 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZP520 UT WOS:000073761700141 ER PT J AU Chhabra, RS Herbert, RA Roycroft, JH Chou, B Miller, RA Renne, RA AF Chhabra, RS Herbert, RA Roycroft, JH Chou, B Miller, RA Renne, RA TI Carcinogenesis studies of tetrahydrofuran vapors in rats and mice SO TOXICOLOGICAL SCIENCES LA English DT Article ID CHEMICALS; TOXICITY AB Tetrahydrofuran (THF) is a widely used industrial solvent and was selected for carcinogenesis studies by the National Toxicology Program (NTP) because of its potential for widespread occupational exposure in humans and a lack of information on animal toxicity and carcinogenicity. Groups of 50 male and 50 female F344/N rats and B6C3F(1) mice were exposed to 0, 200, 600, or 1800 ppm THF by inhalation, 6 h per day, 5 days per week, for 105 weeks. Survival and mean body weights of male and female rats exposed to THF were comparable to that of the controls. No clinical findings or nonneoplastic lesions related to THF exposure were observed in male or female rats. The incidences of renal tubule epithelial adenoma or carcinoma (combined) in exposed male rats occurred with a positive trend, and in males exposed to 600 and 1800 ppm exceeded the historical range for controls in 2-year NTP inhalation studies. There were no other neoplastic lesions related to THF exposure observed in male or female rats. After week 36, the survival of male mice exposed to 1800 ppm was significantly lower than that of the controls. Mean body weights of male and female mice exposed to THF were similar to those of the controls throughout the study. Male mice exposed to 1800 ppm were observed in a state of narcosis during and up to 1 h after the exposure periods. Nonneoplastic lesions related to THF exposure were not observed in male or female mice. The neoplastic lesions related to THF exposure were seen in female mice only. In female mice exposed to 1800 ppm, the incidences of hepatocellular neoplasms were significantly greater than those in the controls. In conclusion, there was some evidence of carcinogenic activity of THF in male F344/N rats due to increased incidences of adenoma or carcinoma (combined) of the kidney at the 600 and 1800 ppm exposure levels. There was clear evidence of carcinogenic activity in female B6C3F(1) mice based on increased incidences of hepatocellular neoplasms at the 1800 ppm exposure level. THF was not carcinogenic in female rats or male mice exposed at 200, 600, or 1800 ppm. C1 Natl Inst Environm Hlth Sci, Res Triangle Pk, NC 27709 USA. Pacific NW Lab, Richland, WA 99352 USA. RP Chhabra, RS (reprint author), Natl Inst Environm Hlth Sci, POB 12233, Res Triangle Pk, NC 27709 USA. NR 15 TC 16 Z9 16 U1 0 U2 2 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 1096-6080 J9 TOXICOL SCI JI Toxicol. Sci. PD FEB PY 1998 VL 41 IS 2 BP 183 EP 188 DI 10.1093/toxsci/41.2.183 PG 6 WC Toxicology SC Toxicology GA ZM361 UT WOS:000073530800006 PM 9520354 ER PT J AU Solanki, RS Gorti, JK Southworth, F AF Solanki, RS Gorti, JK Southworth, F TI Using decomposition in large-scale highway network design with a quasi-optimization heuristic SO TRANSPORTATION RESEARCH PART B-METHODOLOGICAL LA English DT Article ID IMPROVEMENTS; ALGORITHMS; MODELS AB The highway network design problem deals with the selection of links from a base network to facilitate the flow of vehicles from origins to destinations. A proper selection of links requires a balance between minimization of travel costs from origins to destinations and minimization of costs incurred in building or improving links in the network. Link construction costs are usually minimized as a part of the objective or constrained by budget availability. National or regional highway network design problems require excessive amounts of computing time, if solved to optimality. This paper presents a variation of the Modified Quasi-Optimization (MQO) heuristic developed by Dionne and Florian (1979). The proposed algorithm solves a large network design problem by decomposing it in a sequence of smaller problems. Additional savings in computation time are achieved by limiting the search in the MQO heuristic to a well-designed set of paths for each OD pair. These paths are generated to suit the network design problem and differ from the K-shortest paths for the OD pairs. The combined use of decomposition and a limited set of paths allows the proposed heuristic to address realistic network design problems. Numerical experience with a problem involving 6563 nodes and 9800 two-ways links is reported. (C) 1998 Elsevier Science Ltd. All rights reserved. C1 Oak Ridge Natl Lab, Div Energy, Ctr Transportat Anal, Oak Ridge, TN 37831 USA. RP Solanki, RS (reprint author), Oak Ridge Natl Lab, Div Energy, Ctr Transportat Anal, POB 2008, Oak Ridge, TN 37831 USA. NR 18 TC 26 Z9 26 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0191-2615 J9 TRANSPORT RES B-METH JI Transp. Res. Pt. B-Methodol. PD FEB PY 1998 VL 32 IS 2 BP 127 EP 140 DI 10.1016/S0191-2615(97)00020-9 PG 14 WC Economics; Engineering, Civil; Operations Research & Management Science; Transportation; Transportation Science & Technology SC Business & Economics; Engineering; Operations Research & Management Science; Transportation GA YN438 UT WOS:000071168600004 ER PT J AU Wullschleger, SD Hanson, PJ Tschaplinski, TJ AF Wullschleger, SD Hanson, PJ Tschaplinski, TJ TI Whole-plant water flux in understory red maple exposed to altered precipitation regimes SO TREE PHYSIOLOGY LA English DT Article DE Acer rubrum; boundary layer conductance; decoupling coefficient; global charge; sap flow; stomatal conductance; transpiration; water stress ID CLIMATE-CHANGE; TRANSPIRATION; FOREST; TREES; DROUGHT; LEAF; RESPONSES; STRESS; PINE; PENNSYLVANIA AB Sap flow gauges were used to estimate whole-plant water flux for five stem-diameter classes of red maple (Acer rubrum L.) growing in the understory of an upland oak forest and exposed to one of three large-scale (0.64 ha) manipulations of soil water content. This Throughfall Displacement Experiment (TDE) used subcanopy troughs to intercept roughly 30% of the throughfall on a "dry" plot and a series of pipes to move this collected precipitation across an "ambient" plot and onto a "wet" plot. Saplings with a stem diameter larger than 10 cm lost water at rates 50-fold greater than saplings with a stem diameter of 1 to 2 cm (326 versus 6.4 mol 1120 tree(-1) day(-1)). These size-class differences were driven largely by differences in leaf area and cross-sectional sapwood area, because rates of water flux expressed per unit leaf area (6.90 mol H2O m(-2) day(-1)) or sapwood area (288 mol H2O dm(-2) day(-1)) were similar among saplings of the five size classes. Daily and hourly rates of transpiration expressed per unit leaf area varied throughout much of the season, as did soil matrix potentials, and treatment differences due to the TDE were observed during two of the seven sampling periods. On July 6, midday rates of transpiration averaged 1.88 mol H2O m(-2) h(-1) for saplings in the "wet" plot, 1.22 mol H2O m(-2) h(-1) for saplings in the "ambient" plot, and 0.76 mol H2O m(-2) h(-1) for saplings in the "dry" plot. During the early afternoon of August 28, transpiration rates were sevenfold lower for saplings in the "dry" plot compared to saplings in the "wet" plot and 2.5-fold lower compared to saplings in the "ambient" plot. Treatment differences in crown conductance followed a pattern similar to that of transpiration, with values that averaged 60% lower for saplings in the "dry" plot compared to saplings in the "wet" plot and 35% lower compared to saplings in the "ambient" plot. Stomatal and boundary layer conductances were roughly equal in magnitude. Estimates of the decoupling coefficient (Omega) ranged between 0.64 and 0.72 for saplings in the three TDE treatment plots. We conclude that red maple saplings growing in the understory of an upland oak forest are responsive to their edaphic and climatic surroundings, and because of either their small stature or their shallow root distribution, or both, are likely to be impacted by precipitation changes similar to those predicted by global climate models. C1 Oak Ridge Natl Lab, Div Environm Sci, Oak Ridge, TN 37831 USA. RP Wullschleger, SD (reprint author), Oak Ridge Natl Lab, Div Environm Sci, POB 2008, Oak Ridge, TN 37831 USA. RI Hanson, Paul J./D-8069-2011; Wullschleger, Stan/B-8297-2012; OI Hanson, Paul J./0000-0001-7293-3561; Wullschleger, Stan/0000-0002-9869-0446; Tschaplinski, Timothy/0000-0002-9540-6622 NR 36 TC 28 Z9 35 U1 0 U2 11 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 FEB PY 1998 VL 18 IS 2 BP 71 EP 79 PG 9 WC Forestry SC Forestry GA YY614 UT WOS:000072165900001 ER PT J AU Miller, DL Gies, RA AF Miller, DL Gies, RA TI Enhancement of ultrasonically-induced hemolysis by perfluorocarbon-based compared to air-based echo-contrast agents SO ULTRASOUND IN MEDICINE AND BIOLOGY LA English DT Article DE ultrasound adverse effects; echocardiography; sonography; cavitation; cell lysis; contrast agents; hemolysis ID FILLED ALBUMIN MICROSPHERES; IN-VITRO; BIOCHEMICAL-CHARACTERIZATION; PULSED ULTRASOUND; CELL-LYSIS; PRESSURE; ALBUNEX; BLOOD AB Hemolysis induced by ultrasonic activation of various contrast-agent gas bodies was investigated. Canine whole blood, with high concentrations of the agents held in 1 mm thick chambers, was exposed in the nearfield of a 2.4-MHz ultrasound beam in a 37 degrees C water bath. Sterile phosphate buffered saline (PBS) served as a control agent without gas bodies. Albunex (R) (Malinckrodt Medical, St. Louis, MO) and Levovist (TM) (Schering AG, Berlin, Germany) represented the air-based contrast agents. The experimental agents FS069 (Optison (TM) Molecular Biosystems Inc., San Diego, CA) and modified MRX-130 (ImaRx Pharmaceutical Corp., Tucson, AZ) represented perfluorocarbon-based contrast agents. No significant ultrasonically-induced hemolysis was detected for the PBS or Levovist (TM) suspensions. After 1 s continuous exposure, ultrasonically-induced hemolysis was significant for Albunex (R) at 0.4 MPa or higher pressure amplitudes, for FS069 at 0.2 MPa and for modified MRX-130 at 0.4 MPa. Hemolysis found after pulsed exposure with 10 mu s pulses and 1 ms pulse repetition period was significant for Albunex (R), FS069 and modified MRX-130 above thresholds of 1.1 MPa, 0.57 MPa and 1.6 MPa, respectively. FS069 led to more hemolysis after pulsed mode exposures of 1 s duration or longer than did Albunex (R), Reduced concentrations of gas bodies gave increased thresholds and reduced hemolysis. These results indicate that improvements in persistence of contrast agents, which increase their clinical utility, may also enhance the potential for cavitational bioeffects. (C) 1998 World Federation for Ultrasound in Medicine & Biology. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Miller, DL (reprint author), Pacific NW Lab, Mail Stop P7-53,POB 999, Richland, WA 99352 USA. FU NCI NIH HHS [CA42947] NR 30 TC 73 Z9 74 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0301-5629 J9 ULTRASOUND MED BIOL JI Ultrasound Med. Biol. PD FEB PY 1998 VL 24 IS 2 BP 285 EP 292 DI 10.1016/S0301-5629(97)00267-6 PG 8 WC Acoustics; Radiology, Nuclear Medicine & Medical Imaging SC Acoustics; Radiology, Nuclear Medicine & Medical Imaging GA YZ643 UT WOS:000072275100013 PM 9550187 ER PT J AU Soll, W Birdsell, K AF Soll, W Birdsell, K TI The influence of coatings and fills on flow in fractured, unsaturated tuff porous media systems SO WATER RESOURCES RESEARCH LA English DT Article ID MODELS AB A numerical study of a single fracture embedded in a porous matrix was performed to investigate the role of fracture coatings and fills on water movement in permeable, fractured porous media. The variables considered were conductivity and continuity of fracture coatings; location, length, and conductivity of fracture fills; combinations of fills and coatings; initial matrix saturation; and inflow boundary conditions. Results from the simulations indicate that in low-saturation, high-capillarity tuff systems, the conditions under which fractures act as rapid flow paths are limited. These conditions include a continuous coating with conductivity several orders of magnitude lower than that of the neighboring matrix, and large inflow rates. However, as initial matrix saturation increases, the amount of fracture flow also increases. Discontinuities in coatings substantially reduce their effectiveness in preventing matrix imbibition. The presence of any coating, however, does produce increased infiltration depths. Fills appear to be effective barriers to fracture flow. C1 Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, Los Alamos, NM 87545 USA. RP Soll, W (reprint author), Univ Calif Los Alamos Natl Lab, Div Earth & Environm Sci, MS F665,Geoanal EES-5, Los Alamos, NM 87545 USA. NR 19 TC 22 Z9 22 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD FEB PY 1998 VL 34 IS 2 BP 193 EP 202 DI 10.1029/97WR02406 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA YU041 UT WOS:000071673900004 ER PT J AU Fuerschbach, PW AF Fuerschbach, PW TI Cathodic cleaning and heat input in variable polarity plasma arc welding of aluminum SO WELDING JOURNAL LA English DT Article AB For variable polarity plasma are welding (VPPAW) of 1100 Al, it was found that the net heat input to the aluminum workpiece did not decrease as independent changes in polarity balance enabled the tungsten electrode to be come the predominant anode in the alternating current are. For the thin sheet edge welds made in this study, the independent parameters used to var); the are current polarity balance were very effective in delivering a wide range of actual are power polarity balance. The ratio of electrode positive polarity are energy to the total are energy ranged from as little as 0.03 to as high as 0.99. Despite this pronounced difference in are polarity, no significant variation in the average are efficiency (net heat input/arc energy) of 0.51 was found. Substantial heating of the workpiece during electrode positive polarity was attributed to field type emission of electrons from the low boiling point aluminum cathode. Unlike thermionic emission at the tungsten, field emission electrons do not cool the cathode. While the actual are efficiencies were relatively constant, there were significant differences in the measured heat input, the weld size, and the effectiveness of the cathodic cleaning. Increases in the are voltage resulted in a gradual increase in are power as the aluminum workpiece became the primary cathode. This resulted in an increase in the measured heat input to the part and an increase in the melted volume. Despite variations in melted volume, no correlation between are polarity and weld dimensions was observed. The effectiveness of positive polarity are power in removing the surface oxide was clearly apparent when examining the resulting welds. Cleaning (i.e., removal of the oxide) can be effectively controlled and optimized through proper selection of the independent parameters used to create the test weld matrix. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Fuerschbach, PW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 27 TC 14 Z9 16 U1 0 U2 5 PU AMER WELDING SOC PI MIAMI PA PO BOX 351040, MIAMI, FL 33135 USA SN 0043-2296 J9 WELD J JI Weld. J. PD FEB PY 1998 VL 77 IS 2 BP 76S EP 85S PG 10 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA YV874 UT WOS:000071872200023 ER PT J AU Reyes, C Sigman, ME Arce, R Barbas, JT Dabestani, R AF Reyes, C Sigman, ME Arce, R Barbas, JT Dabestani, R TI Photochemistry of acenaphthene at a silica gel/air interface SO JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY LA English DT Article DE acenapthene; photochemistry; silica-gel air interface ID POLYCYCLIC AROMATIC-HYDROCARBONS; DRY SILICA; SIO2; PHOTOLYSIS; MECHANISM; PRODUCTS; PHOTODECOMPOSITION; ANTHRACENE; MOLECULES; SURFACE AB The photolysis of acenapthene (ACE) has been studied at a silica gel/air interface. Direct photolysis leads to 1-acenaphthenol as the principal photoproduct. Secondary photochemical conversion of the alcohol into 1-acenaphthenone is also observed. Reactions leading to formation of both 1-acenaphthenol and 1-acenaphthenone are attributed to electron-transfer oxidation mechanisms and the cation radical of ACE is directly observed by transient diffuse reflectance spectroscopy. Preconditioning the silica gel by heating at 200 degrees C in air partially removes physisorbed water from the silica surface and photochemical conversion of ACE is observed to occur faster. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Puerto Rico, Dept Chem, Rio Piedras, PR 00931 USA. Valdosta State Univ, Dept Chem, Valdosta, GA 31698 USA. RP Sigman, ME (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, POB 2008,MS 6100, Oak Ridge, TN 37831 USA. EM sigmanme@ornl.gov NR 27 TC 21 Z9 21 U1 1 U2 3 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 1010-6030 J9 J PHOTOCH PHOTOBIO A JI J. Photochem. Photobiol. A-Chem. PD JAN 31 PY 1998 VL 112 IS 2-3 BP 277 EP 283 DI 10.1016/S1010-6030(97)00290-6 PG 7 WC Chemistry, Physical SC Chemistry GA YZ903 UT WOS:000072306000029 ER PT J AU Aubert, JH AF Aubert, JH TI Solubility of carbon dioxide in polymers by the quartz crystal microbalance technique SO JOURNAL OF SUPERCRITICAL FLUIDS LA English DT Article DE carbon dioxide solubility; diagnostic; polymers; quartz crystal microbalance ID POLYMERIZATION; SORPTION AB The use of a quartz crystal microbalance (QCM) has been demonstrated to be an accurate and relatively easy technique to measure gas solubility in polymers at high pressures. The technique is reversible and could be used for real-time monitoring of a process. We have compared solubility measurements of CO2 into numerous polymers with literature data, obtained from measurements using a gravimentric approach, with good agreement. With improved electronic sensitivity, this technique could be extended to measure the partitioning of a component present at low levels of CO2 into polymers. This would provide a direct measurement technique that would provide value to investigations into the use of CO2 as an agent to infuse chemicals into polymers. (C) 1998 Elsevier Science B.V. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Aubert, JH (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 19 TC 74 Z9 76 U1 0 U2 19 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0896-8446 J9 J SUPERCRIT FLUID JI J. Supercrit. Fluids PD JAN 31 PY 1998 VL 11 IS 3 BP 163 EP 172 DI 10.1016/S0896-8446(97)00033-8 PG 10 WC Chemistry, Physical; Engineering, Chemical SC Chemistry; Engineering GA ZN070 UT WOS:000073605700003 ER PT J AU Dowben, PA Waldfried, C Komesu, T Welipitiya, D McAvoy, T Vescovo, E AF Dowben, PA Waldfried, C Komesu, T Welipitiya, D McAvoy, T Vescovo, E TI The occupied and unoccupied electronic structure of adsorbed ferrocene SO CHEMICAL PHYSICS LETTERS LA English DT Article ID MO-SCF CALCULATION; IONIZATION-POTENTIALS; PHOTOELECTRON-SPECTROSCOPY; SHELL EXCITATION; METALLOCENES; PHOTOEMISSION; ADSORPTION; SPECTRA AB We have studied both the occupied and unoccupied molecular orbitals of adsorbed ferrocene. The occupied molecular orbitals have been identified using a combination of photoemission selection rules and resonant photoemission. Ferrocene adsorbs with a strong preferential molecular orientation on Mo(112) at 150 K, like metallocenes on many other surfaces. Though the ferrocene molecular axis is largely parallel with the Mo(112) surface there is very little perturbation of the molecular orbitals relative to the gas phase. (C) 1998 Elsevier Science B.V. C1 Univ Nebraska, Behlen Lab Phys, Dept Phys & Astron, Lincoln, NE 68588 USA. Univ Nebraska, Ctr Mat Res & Anal, Lincoln, NE 68588 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source, Upton, NY 11973 USA. RP Dowben, PA (reprint author), Univ Nebraska, Behlen Lab Phys, Dept Phys & Astron, Lincoln, NE 68588 USA. NR 36 TC 19 Z9 19 U1 0 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 30 PY 1998 VL 283 IS 1-2 BP 44 EP 50 DI 10.1016/S0009-2614(97)01316-X PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZB859 UT WOS:000072515200008 ER PT J AU Wen, L Melendres, CA AF Wen, L Melendres, CA TI On the mechanism of hematite deposition on a metal surface under nucleate boiling conditions SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE hematite; deposition; metal surface; scanning electron microscopy; microlayer evaporation model ID OXIDE AB The deposition of colloidal hematite particles on a stainless steel surface under nucleate boiling conditions at 100 degrees C was studied using video and scanning electron microscopy techniques. Deposition was found to occur primarily at the interface boundary of the gas-bubble-liquid-solid (heated surface). The amount of deposit depended mainly on the size of the bubble and its residence time on the surface. Particle-bubble collisions apparently result in attachment of the particles to the bubble because of their hydrophobic nature and subsequent accumulation at the triple interface. These results suggest a mechanism of deposition which is different from the generally employed microlayer evaporation model. A "Partiubble Theory" which emphasizes the central role of particle-bubble interaction in the deposition of hydrophobic hematite suspensions appears more appropriate and is suggested. (C) 1998 Elsevier Science B.V. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. RP Melendres, CA (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 13 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD JAN 30 PY 1998 VL 132 IS 2-3 BP 315 EP 319 DI 10.1016/S0927-7757(97)00189-1 PG 5 WC Chemistry, Physical SC Chemistry GA ZG025 UT WOS:000072957300021 ER PT J AU Leon-Escamilla, EA Corbett, JD AF Leon-Escamilla, EA Corbett, JD TI Hydrogen stabilization. Nine isotypic orthorhombic A(5)Pn(3)H phases (among A=Ca, Sr, Ba, Sm, Eu, Yb; Pn=Sb, Bi) formerly described as binary beta-Yb5Sb3-type compounds SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE hydrogen impurities; Zintl phases; interstitial hydrides; synthesis and structure; properties ID INTERSTITIAL COMPOUNDS; ALKALINE-EARTH; CLUSTERS; METALS; HOST AB Pervasive but commonly unappreciated hydrogen impurities in the indicated divalent metals or in reaction systems at high temperature have led to misreports of Ca(5)Pn(3)H, Sr(5)Pn(3)H, Eu(5)Pn(3)H and Yb(5)Pn(3)H for Pn=Sb, Bi as binary phases with the orthorhombic beta-Yb5Sb3-type structure (space group Pnma). Sm5Bi3H is a new member and contains Sm2+. These phases do not form, or are decomposed into hexagonal Mn5Si3(H-x)-type analogues, in heated systems under dynamic high vacuum. The structure of these hydrides is better described as orthorhombic Ca5Sb3F-type with H or F in tetrahedral interstitial sites; Sr(5)Pn(3)F and Y5Sb3F are new examples of the latter group. Both the Ca5Sb3F- and Mn5Si3-type A(5)Pn(3)H(x) phases show appreciable ranges of hydrogen content. The relative stabilities of the orthorhombic hydrides increase with decreasing cation size and, secondarily, for Bi over Sb. EHMO band calculations for the reported binary Ca5Bi3 (Yb5Sb3-type) structure signal the presence of a bound interstitial by the appearance of underutilized calcium states in a half-filled band at E-F that are displaced on hydrogen inclusion in the correct site. Magnetic and resistivity data are also reported. (C) 1998 Elsevier Science S.A. C1 Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, US DOE, Ames, IA 50011 USA. RP Corbett, JD (reprint author), Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. NR 46 TC 44 Z9 44 U1 0 U2 5 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JAN 30 PY 1998 VL 265 IS 1-2 BP 104 EP 114 DI 10.1016/S0925-8388(97)00320-4 PG 11 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZA255 UT WOS:000072344900019 ER PT J AU Burns, JB Peterson, JR Haire, RG AF Burns, JB Peterson, JR Haire, RG TI Standard enthalpies of formation for europium, gadolinium, and lutetium oxychlorides, calculated from measured enthalpies of solution SO JOURNAL OF ALLOYS AND COMPOUNDS LA English DT Article DE europium; gadolinium; lutetium; oxychlorides; enthalpies ID YTTRIUM AB The enthalpies of solution in 1.000 N HCl of Eu, Gd, and Lu oxychlorides (both powder and single crystal samples) were measured on the 50-1150 mu g scale, and their standard enthalpies of formation at 298 K calculated. The lanthanide oxychlorides (LnOCl) were prepared from the corresponding sesquioxides by treatment with gaseous HCl. Single crystals were grown from a 1:10 (Eu, Gd) or 1:1 (Lu) mixture of sesquioxide-in-trichloride flux. Prior estimations of the standard enthalpies of formation for these three oxychlorides were made, based upon the thermodynamic systematics of LnCl(3) and LnOCl as a function of Ln(III) ionic radius. Standard formation enthalpies at 298 K determined in this work are: Delta(f)H(0)(EuOCl(cr))=-903.5+/-3 kJ mol(-1); Delta(f)H(0)(GdOCl(cr))=-981.4+/-3 kJ mol(-1); and Delta(f)H(0)(LuOCl(cr))=-987.2+/-4 kJ mol(-1). These results are in accord with the estimations made. In addition, the standard enthalpy of formation of promethium oxychloride, Delta(f)H(0)(PmOCl(cr)), which is unknown and difficult to obtain experimentally, was estimated on the basis of interpolation within the lanthanide systematics to be -997+/-4 kJ mol(-1). (C) 1998 Elsevier Science S.A. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Pellissipi State Tech Community Coll, Dept Nat Sci, Knoxville, TN 37933 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Transuranium Res Lab, Oak Ridge, TN 37831 USA. RP Peterson, JR (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 17 TC 3 Z9 3 U1 1 U2 8 PU ELSEVIER SCIENCE SA PI LAUSANNE PA PO BOX 564, 1001 LAUSANNE, SWITZERLAND SN 0925-8388 J9 J ALLOY COMPD JI J. Alloy. Compd. PD JAN 30 PY 1998 VL 265 IS 1-2 BP 146 EP 152 DI 10.1016/S0925-8388(97)00435-0 PG 7 WC Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Chemistry; Materials Science; Metallurgy & Metallurgical Engineering GA ZA255 UT WOS:000072344900026 ER PT J AU Teppen, BJ Yu, CH Miller, DM Schafer, L AF Teppen, BJ Yu, CH Miller, DM Schafer, L TI Molecular dynamics simulations of sorption of organic compounds at the clay mineral aqueous solution interface SO JOURNAL OF COMPUTATIONAL CHEMISTRY LA English DT Article DE molecular dynamics simulations; clay mineral adsorption; clay mineral parameter development; trichloroethene adsorption on clay minerals; organic chlorine electrostatic charges ID MONTE-CARLO SIMULATIONS; ELECTROSTATIC POTENTIALS; UNSATURATED CONDITIONS; HALOGENATED ORGANICS; ATOMIC CHARGES; SMECTITE CLAY; MODEL SOLIDS; ADSORPTION; MONTMORILLONITE; DESORPTION AB The adsorption of trichloroethene, C(2)HCl(3), on clay mineral surfaces in the presence of water has been modeled as an example describing a general program that uses molecular dynamics simulations to study the sorption of organic materials at the clay mineral/aqueous solution interface. Surfaces of the clay minerals kaolinite and pyrophyllite were hydrated at different water levels corresponding to partial and complete monolayers of water. In agreement with experimental trends, water was found to outcompete C(2)HCl(3) for clay surface sites. The simulations suggest that at least three distinct mechanisms coexist for C(2)HCl(3) on clay minerals in the environment. The most stable interaction of C(2)HCl(3) with clay surfaces is by full molecular contact, coplanar with the basal surface. This kind of interaction is suppressed by increasing water loads. A second less stable and more reversible interaction involves adsorption through single-atom contact between one Cl atom and the surface. In a third mechanism, adsorbed C(2)HCl(3) never contacts the clay directly but sorbs onto the first water layer. To test the efficacy of existing force field parameters of organic compounds in solid state simulations, molecular dynamics simulations of several representative organic crystals were also performed and compared with the experimental crystal structures. These investigations show that, in general, in condensed-phase studies, parameter evaluations are realistic only when thermal motion effects are included in the simulations. For chlorohydrocarbons in particular, further explorations are needed of atomic point charge assignments. (C) 1998 John Wiley & Sons, Inc. C1 Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. Univ Arkansas, Dept Agron, Fayetteville, AR 72701 USA. Univ Arkansas, Dept Chem, Fayetteville, AR 72701 USA. RP Teppen, BJ (reprint author), Savannah River Ecol Lab, Adv Analyt Ctr Environm Sci, Aiken, SC 29802 USA. EM teppen@srel.edu NR 42 TC 68 Z9 70 U1 2 U2 20 PU WILEY-BLACKWELL PI MALDEN PA COMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USA SN 0192-8651 J9 J COMPUT CHEM JI J. Comput. Chem. PD JAN 30 PY 1998 VL 19 IS 2 BP 144 EP 153 PG 10 WC Chemistry, Multidisciplinary SC Chemistry GA YP392 UT WOS:000071272300007 ER PT J AU Ostensen, RW AF Ostensen, RW TI Tracer tests and contaminant transport rates in dual-porosity formations with application to the WIPP SO JOURNAL OF HYDROLOGY LA English DT Article DE solute transport; fractures; diffusion; tracers; radioactive waste ID FRACTURED POROUS-MEDIA; LARGE-SCALE FLOW; FISSURED ROCKS; SOLUTE TRANSPORT; MATRIX DIFFUSION; DISPERSION; GRANITE AB Transport of contaminants was analyzed for dual-porosity formations in which advection occurs only through fractures, but contaminants can diffuse into the rock matrix porosity. Transport was shown to occur in three distinct regimes: fracture, dual-porosity and total porosity transport. In the fracture transport regime, contaminant transport is controlled by fracture porosity alone. This was shown to end too quickly to have any significance ibr nuclear waste repositories like the Waste Isolation Pilot Plant (WIPP). Dual-porosity transport, in which contaminants are predominantly inside the matrix porosity and in the process of diffusing deeper into the rock, was shown to be controlled by a single formation parameter, called here the transport length, which can be estimated from tracer tests. Although conventional two-well tracer tests yield ambiguous values for fracture width and porosity, they provide useable estimates of the transport length. The effect on tracer tests of random heterogeneity and anisotropy in the formation was analyzed; the arithmetic mean of inferred values from different tests is the correct average for the transport length and the harmonic mean is the correct average for the kinematic porosity. Data were analyzed from nine tracer tests in a dual-porosity dolomite in the Culebra formation above the WIPP repository, including one test repeated at a different flow rare. The effect of dual-porosity on the mean transport rate of contaminants potentially leaking from the WIPP repository was shown to be negligible. Thus, for off-site transport at the WIPP, the formation is adequately modeled as a single-porosity, matrix-only medium. (C) 1998 Published by Elsevier Science B.V. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Ostensen, RW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 31 TC 10 Z9 10 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0022-1694 J9 J HYDROL JI J. Hydrol. PD JAN 30 PY 1998 VL 204 IS 1-4 BP 197 EP 216 DI 10.1016/S0022-1694(97)00120-0 PG 20 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA YZ756 UT WOS:000072288500014 ER PT J AU Romm, J Levine, M Brown, M Petersen, E AF Romm, J Levine, M Brown, M Petersen, E TI A road map for US carbon reductions SO SCIENCE LA English DT Article C1 US DOE, Off Energy Efficiency & Renewable Energy, Washington, DC 20585 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA. Oak Ridge Natl Lab, Energy Efficiency & Renewable Energy Program, Oak Ridge, TN 37831 USA. RP Romm, J (reprint author), US DOE, Off Energy Efficiency & Renewable Energy, Washington, DC 20585 USA. NR 5 TC 17 Z9 18 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 30 PY 1998 VL 279 IS 5351 BP 669 EP 670 DI 10.1126/science.279.5351.669 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YU574 UT WOS:000071731500022 ER PT J AU Schiffer, J AF Schiffer, J TI Physics - Sparse crystals SO SCIENCE LA English DT Article ID ONE-COMPONENT PLASMA; STORAGE RING C1 Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. Univ Chicago, Chicago, IL 60637 USA. RP Schiffer, J (reprint author), Argonne Natl Lab, Div Phys, Argonne, IL 60439 USA. EM schiffer@anph13.phy.anl.gov NR 9 TC 5 Z9 6 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 30 PY 1998 VL 279 IS 5351 BP 675 EP 676 DI 10.1126/science.279.5351.675 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YU574 UT WOS:000071731500026 ER PT J AU Miller, WH AF Miller, WH TI "Direct" and "correct" calculation of canonical and microcanonical rate constants for chemical reactions SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Review ID TRANSITION-STATE THEORY; DISCRETE VARIABLE REPRESENTATION; THERMAL RATE CONSTANTS; CUMULATIVE REACTION PROBABILITY; KOHN VARIATIONAL PRINCIPLE; INTEGRAL CROSS-SECTIONS; S-MATRIX VERSION; QUANTUM-MECHANICAL CALCULATION; ABSORBING BOUNDARY-CONDITIONS; SCATTERING-THEORY AB Theoretical approaches for calculating rate constants of chemical reactions-either the microcanonical rate for a given total energy k(E) or the canonical rate for a given temperature k(T)-are described that are both "direct", i.e., bypass the necessity of having to solve the complete state-to-state quantum reactive scattering problem, yet also "correct", i.e., in principle exact (given a potential energy surface, assuming nonrelativistic quantum mechanics, etc.) Applications to a variety of reactions are presented to illustrate the methodology for various dynamical situations, e.g., transition-state-theory-like dynamics where the system moves directly through the interaction (transition-state) region and reactions that form long-lived collision complexes. It is also shown how this rigorous quantum theory can be combined with the Lindemann mechanism for describing the effects of collisions with a bath gas, so as to be able to treat recombination reactions and other effects of pressure. Finally, several ways are discussed for combining these rigorous approaches for small molecule dynamics with an approximate treatment of (perhaps many) other degrees of freedom (i.e., a solvent, a substrate, a cluster environment) that may be coupled to it. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Miller, WH (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 108 TC 135 Z9 135 U1 6 U2 18 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 29 PY 1998 VL 102 IS 5 BP 793 EP 806 DI 10.1021/jp973208o PG 14 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV452 UT WOS:000071825600001 ER PT J AU Thorn, RP Monks, PS Stief, LJ Kuo, SC Zhang, ZY Ross, SK Klemm, RB AF Thorn, RP Monks, PS Stief, LJ Kuo, SC Zhang, ZY Ross, SK Klemm, RB TI Photoionization-efficiency spectrum and ionization energy of the cyanomethyl radical CH2CN and products of the N(S-4)+C2H3 reaction SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID GAS-PHASE REACTIONS; RATE-CONSTANT; PHOTOELECTRON-SPECTRA; REACTION CHANNELS; ACETONITRILE; THERMOCHEMISTRY; KINETICS; NITROGEN; DIOXIDE; ATOMS AB Photoionization efficiency (PIE) spectra of the CH2CN radical were measured over the wavelength range lambda = 115-130 nm using a discharge-flow-photoionization mass spectrometer coupled to a dispersed synchrotron-radiation source. The cyanomethyl radical was produced by the reaction F + CH3CN --> CH2CN + HF, and the PIE spectrum displayed steplike behavior near threshold, From the half-rise point of the initial step, a value of 10.28(0) +/- 0.01(0) eV was obtained for the adiabatic ionization energy (IE) of CH2CN based on five independent determinations. From a single measurement of the PIE spectrum and threshold for CD2CN, we obtain IE(CD2CN) = 10.24 eV. The experimental result for CH2CN is compared with previous measurements, estimates, and calculations. The present PIMS study of the CH2CN radical provides experimental measurements of the adiabatic ionization energy that are simultaneously the most direct and the must precise available. For the reaction N(S-4) + C2H3, the C2H2N radical product exhibits a PIE spectrum that may include CH2CN along with another species that has a gradual threshold that is at a considerably longer wavelength than the steplike threshold of CH2CN (derived from F + CH3CN). A possible source of this difference is the contribution from higher-energy C2H2N isomers and/or from excited CH2CN, In sharp contrast to the results for the N(S-4) + C2H3 reaction, no signal attributable to an isomer of the C2D2N radical was observed from the N(S-4) + C2H3 reaction, The C2H3N/C2D3N adducts from the N(S-4) + C2H3/C2D3 reactions were also studied. The adduct was observed to be solely CH3CN for the N(S-4) + C2H3 reaction, while for N(S-4) + C2D3, the PIE spectrum appears to include significant contributions from both the lowest-energy isomer CD3CN and one or more higher-energy isomers. C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Klemm, RB (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Code 690, Greenbelt, MD 20771 USA. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 25 TC 22 Z9 22 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 29 PY 1998 VL 102 IS 5 BP 846 EP 851 DI 10.1021/jp973164j PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV452 UT WOS:000071825600007 ER PT J AU Norby, P Poshni, FI Gualtieri, AF Hanson, JC Grey, CP AF Norby, P Poshni, FI Gualtieri, AF Hanson, JC Grey, CP TI Cation migration in zeolites: An in situ powder diffraction and MAS NMR study of the structure of zeolite Cs(Na)-Y during dehydration SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SOLID-STATE NMR; CRYSTAL-STRUCTURE; NA-23; NAX AB In situ synchrotron X-ray powder diffraction and Cs-133 and Na-23 MAS NMR have been used to investigate the cation migration and ordering in samples of cesium-exchanged zeolite NaY as a function of temperature and cesium cation-exchange level and during dehydration. Samples were prepared with cesium-exchange levels varying from 68 to 83% of the total cation content by carrying out repeated ion-exchange and calcination steps. Lower cesium content samples contain sodium cations in the sodalite cages and cesium cations in the supercages (SII and SIII) directly after the ion-exchange process. After dehydration at 350 degrees C and above, sodium cations are observed in the supercages (in SII) and in the double B-rings (SI). A maximum of 8 cesium cations/unit cell (1/sodalite cage) migrate from the super to the sodalite cages, occupying SII' and SI' positions. The supercage sodium cations are then exchanged for cesium in the subsequent ion-exchange steps, increasing the cesium content. In situ X-ray data, collected during dehydration, showed that the sodium migration from SI' to SI occurs initially (at > 180 degrees C). This migration appears to be accompanied by, or drives, the migration of Cs+ from the supercages to the sodalite cages, which occurs at approximately the same temperature (> 200 degrees C). It is not until > 300 degrees C that the migration of SI' sodium cations to SII is observed. Significant variations in the cation occupancies within the cages are seen at different temperatures in the dehydrated samples. For example, at 500 degrees C, there are an equal number of SII and SIII' cesium cations in the lower cesium content sample. On cooling, the cesium cations order in the SII position, the SIII' occupancy dropping from 12.5 to 7. An ordering scheme for the cations in the supercage is suggested to explain these observations. A number of resonances are seen in the Cs-133 MAS NMR, which are assigned, making use of the occupancies obtained from the Rietveld refinements, to the various cesium positions. The lack of spinning sidebands associated with some of the resonances indicates that the some cations in the supercages are mobile, even at room temperature. When the temperature is raised, a number of SII and Sm resonances coalesce, as the cation mobility in the supercages increases. C1 SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. Univ Modena, Dipartimento Sci Terra, I-41100 Modena, Italy. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Grey, CP (reprint author), SUNY Stony Brook, Dept Chem, Stony Brook, NY 11794 USA. RI Hanson, jonathan/E-3517-2010; Gualtieri, Alessandro/L-9680-2015; Norby, Poul/B-9047-2014 OI Gualtieri, Alessandro/0000-0002-4414-9603; Norby, Poul/0000-0002-2590-7050 NR 34 TC 97 Z9 97 U1 1 U2 31 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 29 PY 1998 VL 102 IS 5 BP 839 EP 856 DI 10.1021/jp9730398 PG 18 WC Chemistry, Physical SC Chemistry GA YV450 UT WOS:000071825400013 ER PT J AU Wu, HM Small, GJ AF Wu, HM Small, GJ TI Symmetry-based analysis of the effects of random energy disorder on the excitonic level structure of cyclic arrays: Application to photosynthetic antenna complexes SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID RHODOBACTER-SPHAEROIDES; OPTICAL-SPECTRA; LOCALIZATION AB We extend the work of Wu and Small who introduced symmetry-adapted basis defect patterns (BDPs) for systematic analysis of the effects of random static energy disorder (diagonal or off-diagonal) on the excitonic level structure of cyclic C-n arrays of chromophores. Examples include the B850 and B875 rings of bacteriochlorophyll (BChl) molecules associated with the LH2 and LH1 antenna complexes of purple bacteria for which, so far, n = 8, 9, and 16. Calculation of the localization/extendedness (chromophore occupation number) patterns and participation numbers of the exciton levels reveals that the effects of random disorder on the exciton levels that contribute to the critically important B850 or B875 absorption band can be understood in terms of a single BDP of e(1) symmetry ("hidden correlation" effect). This is a consequence of the structures of the complexes, the complexes falling in the weak disorder regime and the strict symmetry selection rules that govern the couplings between zero-order exciton levels by BDPs. The above finding greatly simplifies computational studies on the effects of random disorder on the spectroscopic properties of the above bands. Our results show that interpretation of electric field (Stark) effects on the B850 and B875 absorption bands must include the effects of energy disorder. Similarities and differences between the effects of diagonal and off-diagonal energy disorder are discussed as is the relevance of oar findings to the superradiant properties of the LH complexes. C1 US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Small, GJ (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 30 TC 45 Z9 46 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1520-6106 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 29 PY 1998 VL 102 IS 5 BP 888 EP 898 DI 10.1021/jp972951d PG 11 WC Chemistry, Physical SC Chemistry GA YV450 UT WOS:000071825400017 ER PT J AU Kolb, EW Turner, MS AF Kolb, EW Turner, MS TI Obituary - David N. Schramm (1945-97) - Astrophysicist who linked outer space to the inner space of particle physics SO NATURE LA English DT Biographical-Item C1 Fermi Natl Accelerator Lab, Dept Theoret Astrophys, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Kolb, EW (reprint author), Fermi Natl Accelerator Lab, Dept Theoret Astrophys, POB 500, Batavia, IL 60510 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 29 PY 1998 VL 391 IS 6666 BP 444 EP 444 DI 10.1038/35044 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YU290 UT WOS:000071701800028 ER PT J AU Delaney, P Choi, HJ Ihm, J Louie, SG Cohen, ML AF Delaney, P Choi, HJ Ihm, J Louie, SG Cohen, ML TI Broken symmetry and pseudogaps in ropes of carbon nanotubes SO NATURE LA English DT Article ID ELECTRONIC-PROPERTIES; MICROTUBULES; TUBULES AB Since the discovery of carbon nanotubes(1), it has been speculated that these materials should behave like nanoscale wires with unusual electronic properties and exceptional strength. Recently, 'ropes' of close-packed single-wall nanotubes have been synthesized in high yield(2). The tubes in these ropes are mainly of the (10,10) type(3), which is predicted to be metallic(4-6), Experiments on individual nanotubes and ropes(7,8) indicate that these systems indeed have transport properties that qualify hem to be viewed as nanoscale quantum wires at low temperature. It has been expected that the close-packing of individual nanotubes into ropes does not change their electronic properties significantly. Here, however, we present first-principles calculations which show that a broken symmetry of the (10,10) tube caused by interactions between tubes in a rope induces a pseudogap of about 0.1 eV at the Fermi level. This pseudogap strongly modifies many of the fundamental, electronic properties: we predict a semimetal-like temperature dependence of the electrical conductivity and a finite gap in the infrared absorption spectrum. The existence of both electron and hole charge carriers will lead to qualitatively different thermopower and Hall-effect behaviours from those expected for a normal metal. C1 Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Seoul Natl Univ, Dept Phys, Seoul 151742, South Korea. Seoul Natl Univ, Ctr Theoret Phys, Seoul 151742, South Korea. RP Louie, SG (reprint author), Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. RI Choi, Hyoung Joon/N-8933-2015 OI Choi, Hyoung Joon/0000-0001-8565-8597 NR 14 TC 281 Z9 283 U1 2 U2 33 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 29 PY 1998 VL 391 IS 6666 BP 466 EP 468 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YU290 UT WOS:000071701800043 ER PT J AU Elliott, JB Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, RP Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, PG Wieman, HH Wienold, T Wolf, K AF Elliott, JB Albergo, S Bieser, F Brady, FP Caccia, Z Cebra, DA Chacon, AD Chance, JL Choi, Y Costa, S Gilkes, ML Hauger, JA Hirsch, AS Hjort, EL Insolia, A Justice, M Keane, D Kintner, JC Lindenstruth, V Lisa, MA Matis, HS McMahan, M McParland, C Muller, WFJ Olson, DL Partlan, MD Porile, NT Potenza, R Rai, G Rasmussen, J Ritter, HG Romanski, J Romero, JL Russo, GV Sann, H Scharenberg, RP Scott, A Shao, Y Srivastava, BK Symons, TJM Tincknell, M Tuve, C Wang, S Warren, PG Wieman, HH Wienold, T Wolf, K CA EOS Collaboration TI The search for the scaling function in the multifragmentation of gold nuclei SO PHYSICS LETTERS B LA English DT Article DE multifragmentation; scaling; critical exponents ID CRITICAL EXPONENTS; PERCOLATION THRESHOLD; PHASE-TRANSITIONS; YIELDS; FRAGMENTATION; PROJECTILES; COLLISIONS; MATTER; SIZE AB It is shown that thermodynamic scaling when applied to systems with few (similar to 150) constituents, in accordance with the theory of critical phenomena, is observed in nuclear multifragmentation. Yields of different nuclear fragments, obtained over a wide range of excitation energies, collapse with some scatter onto a universal curve. This curve is the nuclear scaling function, which is intimately related to the free energy of the system. The determination of the scaling function forms the basis for quantitatively predicting the critical behavior in nuclei. (C) 1998 Elsevier Science B.V. C1 Purdue Univ, W Lafayette, IN 47907 USA. Univ Catania, I-95129 Catania, Italy. Ist Nazl Fis Nucl, Sez Catania, I-95129 Catania, Italy. Univ Calif Davis, Davis, CA 95616 USA. GSI Darmstadt, D-64220 Darmstadt, Germany. Kent State Univ, Kent, OH 44242 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Purdue Univ, W Lafayette, IN 47907 USA. RI Insolia, Antonio/M-3447-2015; TUVE', Cristina/P-3933-2015 OI Insolia, Antonio/0000-0002-9040-1566; TUVE', Cristina/0000-0003-0739-3153 NR 37 TC 35 Z9 35 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 JAN 29 PY 1998 VL 418 IS 1-2 BP 34 EP 41 DI 10.1016/S0370-2693(97)01403-2 PG 8 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZC812 UT WOS:000072620600006 ER PT J AU Lykken, J Montroy, T Willenbrock, S AF Lykken, J Montroy, T Willenbrock, S TI Group-theoretic evidence for SO(10) grand unification SO PHYSICS LETTERS B LA English DT Article ID ANOMALY CANCELLATION; ELECTRIC CHARGE; STANDARD MODEL; QUANTIZATION AB The hypercharges of the fermions are not uniquely determined in SO(10) grand unification, but rather depend upon which linear combination of the two U(1) subgroups of SO(10) superset of SU(3) x SU(2) x U(1) x U(1) remains unbroken. We show that, in general, a given hypercharge assignment can be obtained only with very high-dimensional Higgs representations. The observation that the standard model is obtained with low-dimensional Higgs representations can therefore be regarded as further evidence for SO(10) grand unification. This evidence is independent of the fact that SO(10) superset of SU(5). (C) 1998 Elsevier Science B.V. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Illinois, Dept Phys, Urbana, IL 61801 USA. RP Lykken, J (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 16 TC 4 Z9 4 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 29 PY 1998 VL 418 IS 1-2 BP 141 EP 144 DI 10.1016/S0370-2693(97)01416-0 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZC812 UT WOS:000072620600021 ER PT J AU Degrassi, G Gambino, P Passera, M Sirlin, A AF Degrassi, G Gambino, P Passera, M Sirlin, A TI The role of M-W in precision studies of the standard model SO PHYSICS LETTERS B LA English DT Article ID INTERDEPENDENCE AB Recent calculations have significantly decreased the scheme and residual scale dependence of basic radiative corrections of the Standard Electroweak Model. This leads to a theoretically accurate prediction of the W-boson mass M-W, as well as a reduced upper bound for the Higgs boson mass M-H. The implications of a precise M-W measurement on the M-H estimate are emphasized. (C) 1998 Elsevier Science B.V. C1 CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Max Planck Inst Phys, W Heisenberg Inst, D-80805 Munich, Germany. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. Univ Padua, Dipartimento Fis, Padua, Italy. NYU, Dept Phys, New York, NY 10003 USA. RP Degrassi, G (reprint author), CERN, Div Theory, CH-1211 Geneva 23, Switzerland. OI Passera, Massimo/0000-0002-7471-4124; Degrassi, Giuseppe/0000-0003-1437-548X; Gambino, Paolo/0000-0002-7433-4914 NR 12 TC 81 Z9 81 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 29 PY 1998 VL 418 IS 1-2 BP 209 EP 213 DI 10.1016/S0370-2693(97)01440-8 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZC812 UT WOS:000072620600031 ER PT J AU Kadlec, RF Zelicoff, AP AF Kadlec, RF Zelicoff, AP TI Physicians and biological warfare agents - Reply SO JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION LA English DT Letter C1 US Dept Def, Washington, DC 20305 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kadlec, RF (reprint author), US Dept Def, Washington, DC 20305 USA. NR 2 TC 1 Z9 1 U1 0 U2 0 PU AMER MEDICAL ASSOC PI CHICAGO PA 515 N STATE ST, CHICAGO, IL 60610 USA SN 0098-7484 J9 JAMA-J AM MED ASSOC JI JAMA-J. Am. Med. Assoc. PD JAN 28 PY 1998 VL 279 IS 4 BP 273 EP 274 PG 2 WC Medicine, General & Internal SC General & Internal Medicine GA YT472 UT WOS:000071607000023 ER PT J AU Campbell, JP Hwang, JW Young, VG Von Dreele, RB Cramer, CJ Gladfelter, WL AF Campbell, JP Hwang, JW Young, VG Von Dreele, RB Cramer, CJ Gladfelter, WL TI Crystal engineering using the unconventional hydrogen bond. Synthesis, structure, and theoretical investigation of cyclotrigallazane SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID GAUSSIAN-BASIS SETS; CORRELATED MOLECULAR CALCULATIONS; GALLIUM NITRIDE; DIFFRACTION; CONVERSION; ALUMINUM; GALLANE; DESIGN AB Cyclotrigallazane, [H2GaNH2](3), was prepared by condensing liquid ammonia onto solid trimethylamine gallane, GaH3(NMe3), at -78 degrees C and allowing the mixture to warm to room temperature and was characterized by IR, mass spectroscopy, elemental analysis, single-crystal X-ray, and neutron powder diffraction. Single-crystal X-ray diffraction at T = -167 degrees C established that the (GaN)(3) ring was in the chair conformation. Neutron powder diffraction data collected at 25 degrees C on the fully deuterated analogue were analyzed with Rietveld refinement to give an average bond distance for Ga-D of 1.56(3) Angstrom and a N-D of 1.04(5) Angstrom. The intermolecular interactions were dominated by four Ga-H ... H-N unconventional hydrogen bonds per molecule that form a chain parallel to the crystallographic a axis. The crystallographically equivalent D ... D bond lengths are 1.97 Angstrom. Calculations revealed that in the gas phase, twist-boat conformations are preferred over chairs for cyclotrigallazane and the related boron and aluminum compounds by 0.9 to 2.6 kcal/mol at correlated levels of electronic structure theory. For cyclotriborazane and cyclotrigallazane, calculations suggest that each H ... H hydrogen bond contributes about 3 kcal/mol to the binding energy (relative to the chair monomer); this value is very slightly higher for cyclotrialumazane. C1 Univ Minnesota, Dept Chem, Minneapolis, MN 55455 USA. Univ Calif Los Alamos Natl Lab, LANSCE, Los Alamos, NM 87545 USA. RP Cramer, CJ (reprint author), Univ Minnesota, Dept Chem, 207 Pleasant St SE, Minneapolis, MN 55455 USA. RI Cramer, Christopher/B-6179-2011 OI Cramer, Christopher/0000-0001-5048-1859 NR 56 TC 80 Z9 80 U1 0 U2 9 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 28 PY 1998 VL 120 IS 3 BP 521 EP 531 DI 10.1021/ja971478e PG 11 WC Chemistry, Multidisciplinary SC Chemistry GA YU772 UT WOS:000071752600008 ER PT J AU Ozolins, V Wolverton, C Zunger, A AF Ozolins, V Wolverton, C Zunger, A TI Strain-induced change in the elastically soft direction of epitaxially grown face-centered-cubic metals SO APPLIED PHYSICS LETTERS LA English DT Article ID COHERENT PHASE-DIAGRAMS; LAYERS; ALLOYS; DENSITY; FILMS AB The theory of epitaxial strain energy is extended beyond the harmonic approximation to account for large film/substrate lattice mismatch. We find that for fee noble metals (i) directions [001] and [111] soften under tensile biaxial strain (unlike zincblende semiconductors) while (ii) [110] and [201] soften under compressive biaxial strain. Consequently, (iii) upon sufficient compression [201] becomes the softest direction (lowest elastic energy), but (iv) [110] is the hardest direction for large tensile strain. (v) The dramatic softening of [001] in fee noble metals upon biaxial tensile strain is caused by small fcc/bcc energy differences for these materials. These results can be used in selecting the substrate orientation for effective epitaxial growth of pure elements and A(p)B(q) superlattices, as well as to explain the shapes of coherent precipitates in phase separating alloys. (C) 1998 American Institute of Physics. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Ozolins, V (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. EM vozolins@sst.nrel.gov RI Wolverton, Christopher/B-7542-2009; Ozolins, Vidvuds/D-4578-2009; Zunger, Alex/A-6733-2013 NR 24 TC 8 Z9 8 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 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 26 PY 1998 VL 72 IS 4 BP 427 EP 429 PG 3 WC Physics, Applied SC Physics GA YT563 UT WOS:000071619600012 ER PT J AU Kwon, C Jia, QX Fan, Y Hundley, MF Reagor, DW Coulter, JY Peterson, DE AF Kwon, C Jia, QX Fan, Y Hundley, MF Reagor, DW Coulter, JY Peterson, DE TI Large magnetoresistance in La0.7Sr0.3MnO3/SrTiO3/La0.7Sr0.3MnO3 ramp-edge junctions SO APPLIED PHYSICS LETTERS LA English DT Article ID DEVICES; FILMS AB We report on the fabrication of ferromagnet-insulator-ferromagnet junction devices using a ramp-edge geometry based on (La0.7Sr0.3)MnO3 ferromagnetic electrodes and a SrTiO3 insulator. The maximum junction magnetoresistance (JMR) as large as 23% is observed below 300 Oe at low temperatures (T<100 K). Our ramp-edge junctions exhibit JMR of 6% at 200 K with a field less than 100 Oe. The device performance at room temperature is believed to be limited by both the nearly equivalent coercive fields in the electrodes and the magnetization process, rather than by the insulating barrier. (C) 1998 American Institute of Physics. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Kwon, C (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop K763, Los Alamos, NM 87545 USA. RI Kwon, Chuhee/A-8687-2008; Jia, Q. X./C-5194-2008 NR 17 TC 66 Z9 68 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 26 PY 1998 VL 72 IS 4 BP 486 EP 488 DI 10.1063/1.120794 PG 3 WC Physics, Applied SC Physics GA YT563 UT WOS:000071619600032 ER PT J AU Casteel, WJ Dixon, DA LeBlond, N Mercier, HPA Schrobilgen, GJ AF Casteel, WJ Dixon, DA LeBlond, N Mercier, HPA Schrobilgen, GJ TI Lewis-acid properties of technetium(VII) dioxide trifluoride, TcO2F3: Characterization by F-19, O-17, and Tc-99 NMR spectroscopy and Raman spectroscopy, density functional theory calculations of TcO2F3, M+TcO2F4- [M = Li, Cs, N(CH3)(4)], and TcO2F3 center dot CH3CN, and X-ray crystal structure of Li+TcO2F4- SO INORGANIC CHEMISTRY LA English DT Article ID OSMIUM TETRAFLUORIDE DIOXIDE; BOND ORDERS; MAGNETIC-RESONANCE; SHIELDING TENSORS; CHEMICAL-SHIFTS; OXIDE FLUORIDE; SCF THEORY; BASIS-SETS; VALENCES; IMPLEMENTATION AB Technetium(VII) dioxide trifluoride, TcO2F3, behaves as a Lewis acid toward the fluoride ion and acetonitrile forming M+TcO2F4- [M = Li, Cs, N(CH3)(4)] salts and TcO2F3 . CH3CN. Fluorine-19 NMR spectroscopy established that the TcO2F4- anion has a cis-dioxo geometry in CH3CN solution. Variable-temperature F-19 NMR studies of TcO2F4- and TcO2F3 . CH3CN in CH3CN revealed that the one-bond couplings between Tc-99 and the two fluorine environments exhibit widely different degrees of quadrupolar collapse. The O-17 NMR spectra of O-17-enriched TcO2F4- and TcO2F3 . CH2CN and the H-1 and C-13 NMR spectra of TcO2F3 . CH3CN indicated that chemical exchange occurs between TcO2F3 . CH3CN and CH3CN solvent. The TcO2F4- anion was characterized by X-rag crystallography as its lithium salt crystallizing in the tetragonal system, space group P (4) over bar 2(1)m, with a =14.706(1) Angstrom, c = 8.797(2) Angstrom, V = 194.8(1) Angstrom(3). and Z = 2. at 20 degrees C, Refinement converged with R = 0.0339 (R-w = 0.0320). The anion geometry is a distorted octahedron with the two oxygen ligands cis to each other and is closely related to the [TcO2F4] units in polymeric TcO2F3. The Raman spectra of M+TcO2F4- [M = Li, Cs, N(CH3)(4)] and TcO2F3 . CH3CN were assigned under C-2v and C-5 point symmetries, respectively. Density functional theory calculations at the local and nonlocal levels predict that monomeric TcO2F3 has a trigonal bipyramidal geometry (C-2v point symmetry) and confirm that the cis-dioxo isomers of TcO2F4- and TcO2F3 . CH3CN (CH3CN bonded trans to an oxygen) are the energy-minimized structures. C1 McMaster Univ, Dept Chem, Hamilton, ON L8S 4M1, Canada. Pacific NW Lab, William Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP McMaster Univ, Dept Chem, 1280 Main St W, Hamilton, ON L8S 4M1, Canada. NR 89 TC 27 Z9 27 U1 1 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 EI 1520-510X J9 INORG CHEM JI Inorg. Chem. PD JAN 26 PY 1998 VL 37 IS 2 BP 340 EP 353 DI 10.1021/ic9708935 PG 14 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YU400 UT WOS:000071713300028 ER PT J AU Fujita, E van Eldik, R AF Fujita, E van Eldik, R TI Effect of pressure on the reversible binding of acetonitrile to the "Co(I)-CO2" adduct to form cobalt(III) carboxylate SO INORGANIC CHEMISTRY LA English DT Article ID CARBON-DIOXIDE ACTIVATION; TERPHENYL-CATALYZED PHOTOREDUCTION; NICKEL(II) COMPLEXES; CRYSTAL-STRUCTURES; COORDINATION MODE; AQUEOUS-SOLUTIONS; PULSE-RADIOLYSIS; REACTION VOLUMES; ABINITIO MO; CO2 C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Univ Erlangen Nurnberg, Inst Inorgan Chem, D-91058 Erlangen, Germany. RP Fujita, E (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Fujita, Etsuko/D-8814-2013 NR 40 TC 19 Z9 19 U1 1 U2 13 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0020-1669 J9 INORG CHEM JI Inorg. Chem. PD JAN 26 PY 1998 VL 37 IS 2 BP 360 EP 362 DI 10.1021/ic971044k PG 3 WC Chemistry, Inorganic & Nuclear SC Chemistry GA YU400 UT WOS:000071713300030 ER PT J AU Yu, ZG Smith, DL Saxena, A Bishop, AR AF Yu, ZG Smith, DL Saxena, A Bishop, AR TI Electronic transmission in conjugated-oligomer tunnel structures: effects of lattice fluctuations SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; LIGHT-EMITTING-DIODES; CONDUCTING POLYMERS; WIRES AB The electronic transmission across metal/conjugated-oligomer/metal structures is discussed, emphasizing the role of lattice fluctuations in short oligomer chains. Four cases are discussed: (a) one oligomer chain, (b) two oligomer chains, (c) chains which form a two-dimensional (2D) structure, and (d) chains which form a three-dimensional (3D) structure, sandwiched between metal contacts. The lattice fluctuations are approximated by white-noise disorder. For the one-chain case, resonant tunnelling occurs when the energy of the incoming electron coincides with an electronic level of the oligomer and the corresponding peak diminishes in intensity on increasing the strength of the disorder. Due to the lattice fluctuations, there is an enhancement of the electronic transmission for energies that lie within the electronic energy gap of the oligomer. In the two-chain case the spatial mirror symmetry with respect to the middle line of the two chains is broken when fluctuations are introduced and coherence between the wave functions of the two chains is partly lost. For the 2D and 3D cases the momentum perpendicular to the oligomer chains is no longer conserved when fluctuations are considered and thus a 'scattered' flux, which represents a deviation from the 'specular' flux, appears. The integrated scattered flux over the energy is a measure of the strength of the fluctuations in the oligomers. If only one of the oligomer chains exhibits lattice fluctuations, the incoming electrons can optimize their path so as to tunnel through the chains with a larger transmission: when the energy of the incoming electron is larger than the gap of the ordered oligomer, the electrons avoid the disordered chain; when the energy of the incoming electron lies in the gap of the ordered oligomer, the probability of electrons being near the disordered chain is enhanced. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Yu, ZG (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RI Yu, Z/B-5547-2009; OI , Zhi-Gang/0000-0002-1376-9025 NR 25 TC 2 Z9 2 U1 0 U2 2 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 26 PY 1998 VL 10 IS 3 BP 617 EP 638 DI 10.1088/0953-8984/10/3/014 PG 22 WC Physics, Condensed Matter SC Physics GA YV404 UT WOS:000071819600014 ER PT J AU Ansell, S Krishnan, S Felten, JJ Price, DL AF Ansell, S Krishnan, S Felten, JJ Price, DL TI Structure of supercooled liquid silicon SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Letter ID X-RAY-DIFFRACTION; MOLTEN SILICON; TEMPERATURE-DEPENDENCE; ELECTRONIC-PROPERTIES; MOLECULAR-DYNAMICS; SI; TRANSITION; SIMULATION; GERMANIUM; GE AB We report x-ray diffraction measurements of the structure factor S(Q) and the radial distribution function g(r) of levitated liquid silicon in the stable and supercooled states. Supercooling results in a sharpening of the first peak in S(Q) and shift to an 8% higher Q value, the appearance of a double shoulder on the high-r side of the first peak in g(r), a sharpening of the first peak in g(r) and a decrease in coordination number. These changes are consistent with a significantly enhanced degree of covalent bonding. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Containerless Res Inc, Evanston, IL 60201 USA. RP Ansell, S (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Price, David Long/A-8468-2013 NR 25 TC 90 Z9 90 U1 1 U2 7 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 26 PY 1998 VL 10 IS 3 BP L73 EP L78 DI 10.1088/0953-8984/10/3/005 PG 6 WC Physics, Condensed Matter SC Physics GA YV404 UT WOS:000071819600005 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, TL Bashindzhagyan, GL Bazarko, AO Ben-David, 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 Cavalli-Sforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G D'Oliveira, A Damerell, CJS Daoudi, M de Groot, N De Sangro, R Dell'Orso, 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 Faro, MJ Frey, R Gillman, T Gladding, G Gonzalez, S Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Oishi, N 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 Schall, 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 Staengle, H 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 Va'vra, 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, 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, TL Bashindzhagyan, GL Bazarko, AO Ben-David, 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 Cavalli-Sforza, M Chou, A Church, E Cohn, HO Coller, JA Cook, V Cotton, R Cowan, RF Coyne, DG Crawford, G D'Oliveira, A Damerell, CJS Daoudi, M de Groot, N De Sangro, R Dell'Orso, 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 Faro, MJ Frey, R Gillman, T Gladding, G Gonzalez, S Hart, EL Harton, JL Hasan, A Hasegawa, Y Hasuko, K Hedges, SJ Hertzbach, SS Hildreth, MD Huber, J Huffer, ME Hughes, EW Hwang, H Iwasaki, Y Jackson, DJ Jacques, P Jaros, JA Jiang, ZY Johnson, AS Johnson, JR Johnson, RA Junk, T Kajikawa, R Kalelkar, M Kang, HJ Karliner, I Kawahara, H Kendall, HW Kim, YD King, ME King, R Kofler, RR Krishna, NM Kroeger, RS Labs, JF Langston, M Lath, A Lauber, JA Leith, DWGS Lia, V Liu, MX Liu, X Loreti, M Lu, A Lynch, HL Ma, J Mancinelli, G Manly, S Mantovani, G Markiewicz, TW Maruyama, T Masuda, H Mazzucato, E McKemey, AK Meadows, BT Messner, R Mockett, PM Moffeit, KC Moore, TB Muller, D Nagamine, T Narita, S Nauenberg, U Neal, H Nussbaum, M Ohnishi, Y Oishi, N 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 Schall, 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 Staengle, H 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 Va'vra, 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, 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 CA SLD Collaboration TI Measurement of R(b) using a vertex mass tag SO PHYSICAL REVIEW LETTERS LA English DT Article ID GLUONS AB We report a new measurement of R(b) = Gamma(Z0-->b (b) over bar)/Gamma(Z0-->hadrons) using a double tag technique, where the b hemisphere selection is based on the reconstructed mass of the B hadron decay vertex. The measurement was performed using a sample of 130 x 10(3) hadronic Z(0) events, collected with the SLD detector at SLC. The method utilizes the 3D vertexing abilities of the CCD pixel vertex detector and the small stable SLC beams to obtain a high b-tagging efficiency and purity. We obtain R(b) = 0.2142 +/- 0.0034(stat) +/- 0.0015(syst) +/- 0.0002(R(c)). [S0031-9007(97)05018-7]. C1 Nagoya Univ, Chikusa Ku, Nagoya, Aichi 464, Japan. 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, 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 37325 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 Groot, Nicolo/A-2675-2009; 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 25 TC 47 Z9 47 U1 0 U2 4 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 660 EP 665 DI 10.1103/PhysRevLett.80.660 PG 6 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100005 ER PT J AU Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, P 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, U Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK 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 Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS 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, K Kirshnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P 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 Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VH Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, P 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, U Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK 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 Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS 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, K Kirshnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P 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 Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VH Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A CA DO Collaboration TI Measurement of dijet angular distributions and search for quark compositeness SO PHYSICAL REVIEW LETTERS LA English DT Article ID CTEQ PARTON DISTRIBUTIONS; P(P)OVER-BAR COLLISIONS; HADRON COLLIDERS; ROOT-S=1.8 TEV; JETS AB We have measured the dijet angular distribution in root s = 1.8 TeV p (p) over bar collisions using the D0 detector. Order alpha(s)(3) QCD predictions are in good agreement with the data. At 95% confidence limit the data exclude models of quark compositeness in which the contact interaction scale is below 2 TeV. [S0031-9007(97)05129-6]. C1 NYU, New York, NY 10003 USA. Univ Los Andes, Bogota, Colombia. Univ Arizona, Tucson, AZ 85721 USA. Boston Univ, Boston, MA 02215 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Brown Univ, Providence, RI 02912 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 14000, DF, Mexico. Columbia Univ, New York, NY 10027 USA. Univ Delhi, Delhi 110007, India. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Chicago, IL 60607 USA. Indiana Univ, Bloomington, IN 47405 USA. Iowa State Univ Sci & Technol, Ames, IA 50011 USA. Korea Univ, Seoul 136701, South Korea. Kyungsung Univ, Pusan 608736, South Korea. Univ Calif Berkeley, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Moscow State Univ, Moscow, Russia. Univ Nebraska, Lincoln, NE 68588 USA. Northeastern Univ, Boston, MA 02115 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Univ Oklahoma, Norman, OK 73019 USA. Panjab Univ, Chandigarh 160014, India. Protvino High Energy Phys Inst, Protvino 142284, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77005 USA. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Univ Rochester, Rochester, NY 14627 USA. CEA, DAPNIA, Serv Phys Particles, CE Saclay, Gif Sur Yvette, France. Seoul Natl Univ, Seoul, South Korea. SUNY Stony Brook, Stony Brook, NY 11794 USA. Tata Inst Fundamental Res, Mumbai 400005, India. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Abbott, B (reprint author), NYU, New York, NY 10003 USA. RI Sznajder, Andre/L-1621-2016; Chekulaev, Sergey/O-1145-2015; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Roe, Natalie/A-8798-2012; 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; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015 OI Sznajder, Andre/0000-0001-6998-1108; Baarmand, Marc/0000-0002-9792-8619; Dudko, Lev/0000-0002-4462-3192; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775 NR 19 TC 44 Z9 44 U1 0 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 666 EP 671 DI 10.1103/PhysRevLett.80.666 PG 6 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100006 ER PT J AU Sun, Y Wu, CL Bhatt, K Guidry, M Feng, DH AF Sun, Y Wu, CL Bhatt, K Guidry, M Feng, DH TI Scissors-mode vibrations and the emergence of SU(3) symmetry from the projected deformed mean field SO PHYSICAL REVIEW LETTERS LA English DT Article ID SHELL-MODEL; MICROSCOPIC CALCULATION; NUCLEAR-DEFORMATION; COLLECTIVE MODES; ROTATION; STATES AB Starting from a deformed potential we construct separate bases of collective neutron and proton rotational states by exact angular momentum projection. These rotational states are then coupled by diagonalizing a residual pairing plus quadrupole interaction. Many new bands emerge that are not found in the rotation of the usual BCS condensate, and may correspond to the geometrical scissors mode and its generalizations. These excitation modes can be understood as rotational bands built on spin-1 (h) over bar phonon excitations; they exhibit a nearly perfect dynamical SU(3) fermion spectrum, even though there is no explicit dynamical symmetry in our model. [S0031-9007(97)05162-4]. C1 Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Chung Yuan Christian Univ, Dept Phys, Chungli 32023, Taiwan. Univ Mississippi, Dept Phys & Astron, University, MS 38677 USA. Drexel Univ, Dept Phys & Atmospher Sci, Philadelphia, PA 19104 USA. RP Sun, Y (reprint author), Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RI Sun, Yang/P-2417-2015 NR 26 TC 17 Z9 18 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 672 EP 675 DI 10.1103/PhysRevLett.80.672 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100007 ER PT J AU Rehm, KE Borasi, F Jiang, CL Ackermann, D Ahmad, I Brown, BA Brumwell, F Davids, CN Decrock, P Fischer, SM Gorres, J Greene, J Hackmann, G Harss, B Henderson, D Henning, W Janssens, RVF McMichael, G Nanal, V Nisius, D NOlen, J Pardo, RC Paul, M Reiter, P Schiffer, JP Seweryniak, D Segel, RE Wiescher, M Wuosmaa, AH AF Rehm, KE Borasi, F Jiang, CL Ackermann, D Ahmad, I Brown, BA Brumwell, F Davids, CN Decrock, P Fischer, SM Gorres, J Greene, J Hackmann, G Harss, B Henderson, D Henning, W Janssens, RVF McMichael, G Nanal, V Nisius, D NOlen, J Pardo, RC Paul, M Reiter, P Schiffer, JP Seweryniak, D Segel, RE Wiescher, M Wuosmaa, AH TI Study of the Ni-56(d,p)Ni-57 reaction and the astrophysical Ni-56(p,gamma)Cu-57 reaction rate SO PHYSICAL REVIEW LETTERS LA English DT Article AB The single-particle character of states outside the doubly magic (radioactive) nucleus Ni-56 has been determined through a measurement of the (d,p) neutron transfer reaction using inverse kinematics. From the spectroscopic factors of the low-lying states in Ni-57, the astrophysically interesting yield for the Ni-56(p,gamma) reaction to thr mirror nucleus Cu-57 has been calculated, utilizing charge symmetry. The rate for this reaction in the temperature range typical of novae, supernovae, and x-ray bursts is found to be more than 10 times higher than previously assumed. [S0031-9007(97)05085-0]. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Michigan State Univ, E Lansing, MI 48824 USA. Univ Notre Dame, South Bend, IN 46556 USA. Hebrew Univ Jerusalem, Jerusalem, Israel. Northwestern Univ, Evanston, IL 60208 USA. RP Rehm, KE (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 17 TC 73 Z9 77 U1 0 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 676 EP 679 DI 10.1103/PhysRevLett.80.676 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100008 ER PT J AU Glimm, J Saltz, D Sharp, DH AF Glimm, J Saltz, D Sharp, DH TI Statistical evolution of chaotic fluid mixing SO PHYSICAL REVIEW LETTERS LA English DT Article ID RAYLEIGH-TAYLOR INSTABILITY; 2-PHASE FLOW; MODELS AB We describe a new constitutive theory for two-phase how models of chaotic mixing layers, which form as two incompressible fluids interpenetrate. This theory is compatible with arbitrary velocities of the edges of a mixing layer, and it gives analytic solutions for the distribution of fluid variables across the layer in terms of these velocities. Our results are in agreement with all available data from planar Rayleigh-Taylor instability experiments. The model that we discuss can be embedded in a larger system of two-phase flow equations in order to predict other important physical quantities, such as the fluid pressures and internal energies in compressible mixing. [S0031-9007(97)04668-1]. C1 SUNY Stony Brook, Stony Brook, NY 11794 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Glimm, J (reprint author), SUNY Stony Brook, Stony Brook, NY 11794 USA. NR 20 TC 32 Z9 33 U1 0 U2 2 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 712 EP 715 DI 10.1103/PhysRevLett.80.712 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100017 ER PT J AU Ditmire, T Gumbrell, ET Smith, RA Djaoui, A Hutchinson, MHR AF Ditmire, T Gumbrell, ET Smith, RA Djaoui, A Hutchinson, MHR TI Time-resolved study of nonlocal electron heat transport in high temperature plasmas SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY-EMISSION; LASER-PULSES; CLUSTERS AB Exploiting the high absorption efficiency of intense, ultrashort laser pulses in gases of atomic clusters we have created plasma filaments with temperatures of >1 keV and electron densities in excess of 10(20) cm(-3). Using picosecond laser pulses, we have interferometrically measured the temporal and spatial evolution of the electron density in these plasmas on a fast (<50 ps) time scale. Our measurements indicate that nonlocal heat transport by hot electrons drives a fast ionization wave, and the data agree well with a nonlocal heat transport model. [S0031-9007(97)05139-9]. C1 Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. Univ London Imperial Coll Sci Technol & Med, Blackett Lab, London SW7 2BZ, England. RP Ditmire, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-440, Livermore, CA 94550 USA. NR 18 TC 54 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 JAN 26 PY 1998 VL 80 IS 4 BP 720 EP 723 DI 10.1103/PhysRevLett.80.720 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100019 ER PT J AU Bendele, GM Stephens, PW Prassides, K Vavekis, K Kordatos, K Tanigaki, K AF Bendele, GM Stephens, PW Prassides, K Vavekis, K Kordatos, K Tanigaki, K TI Effect of charge state on polymeric bonding geometry: The ground state of Na2RbC60 SO PHYSICAL REVIEW LETTERS LA English DT Article ID C-60 DIMERS; ELECTRONIC-STRUCTURE; MOLECULAR-DYNAMICS; OPTICAL-ABSORPTION; PRESSURE; FULLERIDE; NA2CSC60; PHASES; ENERGY AB Theoretical calculations have predicted all fullerene polymers to have interfullerene connections via [2 + 2] cycloaddition. We find that the ground state of Na2RbC60 is a one-dimensional polymer of fullerene molecules connected by single carbon-carbon bonds. We discuss and exclude possible steric and kinetic reasons for this discrepancy. Our results imply that it is the charge state of the fullerene molecule that drives the bonding mechanism, causing (C-60(1-))(n) and neutral (C-60)(n) to favor cycloaddition and (C-60(3-))(n) to favor single carbon-carbon bonds. [S0031-9007(97)05104-1]. C1 SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Univ Sussex, Sch Chem Phys & Environm Sci, Brighton BN1 9QJ, E Sussex, England. NEC Corp Ltd, Fundamental Res Labs, Tsukuba, Ibaraki 305, Japan. RP Bendele, GM (reprint author), SUNY Stony Brook, Dept Phys & Astron, Stony Brook, NY 11794 USA. RI Tanigaki, Katsumi/A-4853-2010; Kordatos, Konstantinos /E-6947-2012; Prassides, Kosmas/C-9804-2009; VAVEKIS, KONSTANTINOS/P-4349-2014 OI Tanigaki, Katsumi/0000-0003-1538-6527; VAVEKIS, KONSTANTINOS/0000-0002-1912-0964 NR 28 TC 93 Z9 93 U1 1 U2 3 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 736 EP 739 DI 10.1103/PhysRevLett.80.736 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100023 ER PT J AU Dodgson, MJW Geshkenbein, VB Nordborg, H Blatter, G AF Dodgson, MJW Geshkenbein, VB Nordborg, H Blatter, G TI Characteristics of first-order vortex lattice melting: Jumps in entropy and magnetization SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TC SUPERCONDUCTORS; YBA2CU3O7-DELTA; TRANSITION; LINE AB We derive expressions for the jumps in entropy and magnetization characterizing the first-order melting transition of a flux line lattice. In our analysis we account for the temperature dependence of the Landau parameters and make use of the proper shape of the melting line as determined by the relative importance of electromagnetic and Josephson interactions. The results agree well with experiments on anisotropic Y1Ba2Cu3O7-delta and layered Bi2Sr2Ca1Cu2O8 materials and reaffirm the validity of the London model. C1 ETH Honggerberg, CH-8093 Zurich, Switzerland. LD Landau Theoret Phys Inst, Moscow 117940, Russia. Argonne Natl Lab, Argonne, IL 60439 USA. RP Dodgson, MJW (reprint author), ETH Honggerberg, CH-8093 Zurich, Switzerland. OI Nordborg, Henrik/0000-0003-3432-3257 NR 16 TC 51 Z9 51 U1 1 U2 1 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 837 EP 840 DI 10.1103/PhysRevLett.80.837 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100049 ER PT J AU Booth, CH Bridges, F Kwei, GH Lawrence, JM Cornelius, AL Neumeier, JJ AF Booth, CH Bridges, F Kwei, GH Lawrence, JM Cornelius, AL Neumeier, JJ TI Direct relationship between magnetism and MnO6 distortions in La1-xCaxMnO3 SO PHYSICAL REVIEW LETTERS LA English DT Article ID X-RAY; COLOSSAL-MAGNETORESISTANCE; DOUBLE EXCHANGE; FILMS; LA0.67CA0.33MNO3; TEMPERATURE; RESISTIVITY; LAMNO3; OXIDE AB Measured distortions of the Mn-O bond length distribution from x-ray-absorption fine-structure measurements are found to relate linearly to the doped hole concentration x at room temperature in La1-xCaxMnO3. Comparison of the distortions above and below T-c for colossal magnetoresistor (CMR) samples gives an estimate of the number of delocalized holes n(dh), and we find that ln(n(dh)) proportional to M (magnetization). These results are complementary to resistance measurements that show that ln(rho) proportional to -M. We have thus established the functional relationship between the electronic, spin, and lattice degrees of freedom in the CMR perovskites. C1 Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. Univ Calif Santa Cruz, Dept Phys, Santa Cruz, CA 95064 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Florida Atlantic Univ, Dept Phys, Boca Raton, FL 33431 USA. RP Booth, CH (reprint author), Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA. RI Cornelius, Andrew/A-9837-2008; Booth, Corwin/A-7877-2008 NR 28 TC 222 Z9 222 U1 1 U2 20 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 26 PY 1998 VL 80 IS 4 BP 853 EP 856 DI 10.1103/PhysRevLett.80.853 PG 4 WC Physics, Multidisciplinary SC Physics GA YU437 UT WOS:000071717100053 ER PT J AU Stohlker, T Ionescu, DC Rymuza, P Bosch, F Geissel, H Kozhuharov, C Ludziejewski, T Mokler, PH Scheidenberger, C Stachura, Z Warczak, A Dunford, RW AF Stohlker, T Ionescu, DC Rymuza, P Bosch, F Geissel, H Kozhuharov, C Ludziejewski, T Mokler, PH Scheidenberger, C Stachura, Z Warczak, A Dunford, RW TI Interference between electric and magnetic amplitudes for K shell excitation of high-Z H-like projectiles SO PHYSICS LETTERS A LA English DT Article ID RELATIVISTIC HEAVY-IONS; ATOM COLLISIONS; INTERMEDIATE VELOCITIES; BI PROJECTILES; IONIZATION AB We report an investigation of projectile K shell excitation for high-Z ions in relativistic ion-atom collisions, For the case of H-like Bi, the excitation process is unambiguously identified by observing the radiative decay of the excited levels to the vacant is shell, in coincidence with ions that did not undergo any charge exchange in the reaction target, The results are compared with detailed relativistic calculations, showing that the magnetic interaction is of considerable importance for the K shell excitation process in high-Z ions, For excitation to the L shell sublevels, the experimental data confirm that the magnetic part of the Lienard-Wiechert interaction must be added coherently with the electric part leading to a significant reduction of the K shell excitation cross section. (C) 1998 Elsevier Science B.V. C1 Univ Frankfurt, Inst Kernphys, D-60486 Frankfurt, Germany. Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Hahn Meitner Inst Kernforsch Berlin GmbH, Bereich Theoret Phys, D-14109 Berlin, Germany. Inst Nucl Studies, PL-05400 Swierk, Poland. Inst Nucl Phys, PL-31342 Krakow, Poland. Jagiellonian Univ, Inst Phys, PL-30059 Krakow, Poland. Argonne Natl Lab, Argonne, IL 60439 USA. RP Stohlker, T (reprint author), Univ Frankfurt, Inst Kernphys, August Euler Str 6, D-60486 Frankfurt, Germany. NR 19 TC 23 Z9 23 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JAN 26 PY 1998 VL 238 IS 1 BP 43 EP 48 DI 10.1016/S0375-9601(97)00895-5 PG 6 WC Physics, Multidisciplinary SC Physics GA YY134 UT WOS:000072116700006 ER PT J AU Gubbi, AN George, EP Ohriner, EK Zee, RH AF Gubbi, AN George, EP Ohriner, EK Zee, RH TI Segregation of lutetium and yttrium to grain boundaries in iridium alloys SO ACTA MATERIALIA LA English DT Article ID FRACTURE AB The equilibrium segregation of lutetium and yttrium to grain boundaries in iridium alloys containing 0.3 wt% tungsten was studied. The segregation level of Lu decreased with increasing annealing temperature whereas that of Y initially increased with increasing temperature but then decreased with further increases in temperature. At all temperatures, Y segregated more strongly than lutetium. The observed segregation behavior of the two dopants was explained on the basis of their free energies of segregation and solid solubilities, and the solvus lines for Lu and Y were obtained from the results. Energies of segregation and energies of solution for Lu and Y in the iridium alloy were also determined. (C) 1998 Acta Metallurgica Inc. C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Auburn Univ, Mat Engn Program, Auburn, AL 36849 USA. RP George, EP (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. RI George, Easo/L-5434-2014 NR 20 TC 7 Z9 8 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 23 PY 1998 VL 46 IS 3 BP 893 EP 902 DI 10.1016/S1359-6454(97)00308-X PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YW752 UT WOS:000071969800017 ER PT J AU Holm, EA Zacharopoulos, N Srolovitz, DJ AF Holm, EA Zacharopoulos, N Srolovitz, DJ TI Nonuniform and directional grain growth caused by grain boundary mobility variations SO ACTA MATERIALIA LA English DT Article ID COMPUTER-SIMULATION; DOMAIN-GROWTH; MONTE-CARLO; POTTS-MODEL; KINETICS; TEMPERATURE; DIMENSIONS AB Most derivations of grain growth relations require an assumption of constant grain boundary mobility; in fact, a number of these relations cannot be derived if boundary mobility varies in space or time. Computer simulations of grain growth in which boundary mobility varies in time and/or space have been performed. When mobility varies continuously with position, grains grow with locally normal kinetics. In contrast, when the mobility profile in discontinuous, deviations from normal growth may appear near the mobility discontinuity. When the boundary mobility varies in lime as well as in space, different growth morphologies can occur. Under a one-dimensional Gaussian mobility profile moving across the sample with some velocity, three growth regimes can occur. At low and high profile velocities, grain growth is equiaxed and normal. At intermediate velocities, a fully columnar grain structure forms; the width of the columnar grains evolves with normal growth kinetics. C1 Sandia Natl Labs, Theoret & Computat Mat Modeling Dept, Albuquerque, NM 87185 USA. Univ Michigan, Dept Mat Sci & Engn, Ann Arbor, MI 48109 USA. RP Holm, EA (reprint author), Sandia Natl Labs, Theoret & Computat Mat Modeling Dept, POB 5800, Albuquerque, NM 87185 USA. RI Holm, Elizabeth/S-2612-2016 OI Holm, Elizabeth/0000-0003-3064-5769 NR 18 TC 29 Z9 32 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 23 PY 1998 VL 46 IS 3 BP 953 EP 964 DI 10.1016/S1359-6454(97)00307-8 PG 12 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YW752 UT WOS:000071969800022 ER PT J AU Manosa, L Jurado, M Gonzalez-Comas, A Obrado, E Planes, A Zarestky, J Stassis, C Romero, R Somoza, A Morin, M AF Manosa, L Jurado, M Gonzalez-Comas, A Obrado, E Planes, A Zarestky, J Stassis, C Romero, R Somoza, A Morin, M TI A comparative study of the post-quench behaviour of Cu-Al-Be and Cu-Zn-Al shape memory alloys SO ACTA MATERIALIA LA English DT Article ID NOBLE-METAL ALLOYS; MARTENSITIC-TRANSFORMATION; EQUILIBRIUM PHASES; ATOMIC ORDER; CALORIMETRY; LIFETIME AB This paper reports a comparative investigation of the effect of quenching on the Cu-Al-Be and Cu-Zn-Al shape memory alloys by the use of several experimental techniques. In a first stage, the order-disorder transitions in these alloys have been characterized by means of modulated calorimetry. Results have proved that the A2 reversible arrow DO3 transition in Cu-Al-Be is first order with a latent heat of 1160 J/mol; the B2 reversible arrow L2(1) transition in Cu-Zn-Al is second order, and a peak in the specific-heal vs temperature curve has been observed. Secondly, the post-quench behaviour of these alloys, when subjected to some of the typical heat treatments used to stabilize the beta phase, has also been studied by means of neutron diffraction, positron annihilation and highly sensitive calorimetry. A different post-quench time evolution of the martensitic transition temperatures has been found for the two alloys. For Cu-Al-Be: this evolution has been shown to be correlated with positron annihilation data, while, for Cu-Zn-Al; a correlation with neutron diffraction data has been established. These results show that the measured shifts in the transition temperatures induced by a quench are mostly due to an excess of vacancies in the case of Cu-Al-Be, and to an incomplete degree of L2(1) atomic order in Cu-Zn-Al. (C) 1998 Acta Metallurgica Inc. C1 Univ Barcelona, Fac Fis, Dept Estructura & Constituents Mat, E-08028 Barcelona, Catalonia, Spain. Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA. Univ Nacl Ctr Prov Buenos Aires, IFIMAT, Tandil, Argentina. Comis Invest Cient Prov Buenos Aires, Buenos Aires, DF, Argentina. Inst Natl Sci Appl, Etud Met Phys & Phys Mat Grp, F-69621 Villeurbanne, France. RP Manosa, L (reprint author), Univ Barcelona, Fac Fis, Dept Estructura & Constituents Mat, Diagonal 647, E-08028 Barcelona, Catalonia, Spain. RI MORIN, Michel/A-2161-2009; Manosa, Lluis/D-8579-2014; Planes, Antoni/O-1904-2015 OI Manosa, Lluis/0000-0002-1182-2670; Planes, Antoni/0000-0001-5213-5714 NR 33 TC 36 Z9 36 U1 0 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 23 PY 1998 VL 46 IS 3 BP 1045 EP 1053 DI 10.1016/S1359-6454(97)00301-7 PG 9 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YW752 UT WOS:000071969800028 ER PT J AU Takahashi, K Abe, K Sawamura, S Jonah, CD AF Takahashi, K Abe, K Sawamura, S Jonah, CD TI Spectroscopic study of 4-aminobenzophenone in supercritical CF3H and CO2: local density and Onsager's reaction cavity radius SO CHEMICAL PHYSICS LETTERS LA English DT Article ID SOLVATION DYNAMICS; DIPOLE SOLVATION; FLUIDS; 9-CYANOANTHRACENE; FLUORESCENCE; SIMULATION; EQUATION; MIXTURES; LIQUIDS; ETHANE AB The measured bathochromic shifts of 4-aminobenzophenone (4ABP) in CF3H are explained by Onsager's reaction field theory (ORFT) if the cavity radius is the sum of Van der Waals radii of solute and solvent, while in CO2, the cavity radius is the solute's Van der Waals radius. The experimental local densities around 4ABP have been estimated and show a maximum at a reduced density of 0.5 for CF3H and 0.7 for CO2. Simulations are consistent with the high local densities found at low bulk densities and suggest possible explanations for the different radii used for CF3H and CO2. (C) 1998 Elsevier Science. B.V. C1 Hokkaido Univ, Fac Engn, Sapporo, Hokkaido 060, Japan. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Takahashi, K (reprint author), Hokkaido Univ, Fac Engn, Sapporo, Hokkaido 060, Japan. RI Takahashi, Kenji/C-8846-2011; Takahashi, Kenji/F-4885-2014 NR 32 TC 24 Z9 24 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2614 J9 CHEM PHYS LETT JI Chem. Phys. Lett. PD JAN 23 PY 1998 VL 282 IS 5-6 BP 361 EP 368 DI 10.1016/S0009-2614(97)01274-8 PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZB235 UT WOS:000072450700004 ER PT J AU Gavin, IM Usachenko, SI Bavykin, SG AF Gavin, IM Usachenko, SI Bavykin, SG TI Nucleosome structural transition during chromatin unfolding is caused by conformational changes in nucleosomal DNA SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID SILENT MATING LOCI; YEAST HISTONE H4; CORE PARTICLE; PRIMARY ORGANIZATION; IONIC-STRENGTH; SACCHAROMYCES-CEREVISIAE; N-TERMINI; TRANSCRIPTION; REPRESSION; DOMAIN AB We have recently reported that certain core histone-DNA contacts are altered in nucleosomes during chromatin unfolding (Usachenko, S. I., Gavin I. M., and Bavykin, S. G. (1996) J. Biol. Chem. 271, 3831-3836), In this work, we demonstrate that these alterations are caused by a conformational change in the nucleosomal DNA, Using zero-length protein-DNA cross linking, we have mapped histone-DNA contacts in isolated core particles at ionic conditions affecting DNA stiffness, which may change the nucleosomal DNA conformation, We found that the alterations in histone-DNA contacts induced by an increase in DNA stiffness in isolated core particles are identical to those observed in nucleosomes during chromatin unfolding. The change in the pattern of micrococcal nuclease digestion of linker histone-depleted chromatin at ionic conditions affecting chromatin compaction also suggests that the stretching of the linker DNA may alter the nucleosomal DNA conformation, resulting in a structural transition in the nucleosome which may play a role in rendering the nucleosome competent for transcription and/or replication. C1 VA Engelhardt Mol Biol Inst, Moscow 117984, Russia. RP Bavykin, SG (reprint author), Argonne Natl Lab, Ctr Mechanist Biol & Biotechnol, 9700 S Cass Ave,Bldg 202, Argonne, IL 60439 USA. EM sbavykin@everest.bim.anl.gov NR 78 TC 14 Z9 15 U1 0 U2 0 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814 USA SN 0021-9258 J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 23 PY 1998 VL 273 IS 4 BP 2429 EP 2434 DI 10.1074/jbc.273.4.2429 PG 6 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YT367 UT WOS:000071595200082 PM 9442093 ER PT J AU Wang, YD DuBois, JL Hedman, B Hodgson, KO Stack, TDP AF Wang, YD DuBois, JL Hedman, B Hodgson, KO Stack, TDP TI Catalytic galactose oxidase models: Biomimetic Cu(II)-phenoxyl-radical reactivity SO SCIENCE LA English DT Article ID CRYSTAL-STRUCTURE; ACTIVE-SITE; COPPER; COMPLEXES; OXIDATION; ALCOHOLS; SYSTEM AB Biomimetic functional models of the mononuclear copper enzyme galactose oxidase are presented that catalytically oxidize benzylic and allylic alcohols to aldehydes with O-2 under mild conditions, The mechanistic fidelity between the models and the natural system is pronounced. Modest structural mimicry proves sufficient to transfer an unusual ligand-based radical mechanism, previously unprecedented outside the protein matrix, to a simple chemical system. C1 Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. Stanford Univ, Dept Chem, Stanford, CA 94305 USA. RP Hedman, B (reprint author), Stanford Univ, Stanford Synchrotron Radiat Lab, Stanford, CA 94309 USA. OI Wang, Yadong/0000-0003-2067-382X FU NCRR NIH HHS [RR-01209]; NIGMS NIH HHS [GM50730] NR 32 TC 324 Z9 327 U1 8 U2 58 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 23 PY 1998 VL 279 IS 5350 BP 537 EP 540 DI 10.1126/science.279.5350.537 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT527 UT WOS:000071616000038 PM 9438841 ER PT J AU Liu, J Feng, XD Fryxell, GE Wang, LQ Kim, AY Gong, ML AF Liu, J Feng, XD Fryxell, GE Wang, LQ Kim, AY Gong, ML TI Hybrid mesoporous materials with functionalized monolayers SO ADVANCED MATERIALS LA English DT Article ID SELF-ASSEMBLED MONOLAYERS; MOLECULAR-SIEVES; SILICA; FILMS; DYNAMICS; NMR AB Functionalized mesoporons materials, in which organized functionalized monolayers are covalently bonded to mesoporous supports, show exceptional selectivity and a capacity for removing heavy metals from waste streams. The synthesis and characterization of hybrid materials such as that shown in the Figure (see also the cover of this issue) are described and their potential applications outlined. C1 Pacific NW Lab, Richland, WA 99352 USA. RP Liu, J (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. NR 34 TC 320 Z9 329 U1 5 U2 52 PU WILEY-V C H VERLAG GMBH PI BERLIN PA MUHLENSTRASSE 33-34, D-13187 BERLIN, GERMANY SN 0935-9648 J9 ADV MATER JI Adv. Mater. PD JAN 22 PY 1998 VL 10 IS 2 BP 161 EP + DI 10.1002/(SICI)1521-4095(199801)10:2<161::AID-ADMA161>3.3.CO;2-H PG 6 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 YU745 UT WOS:000071750000013 ER PT J AU Xu, CS Taylor, TR Burton, GR Neumark, DM AF Xu, CS Taylor, TR Burton, GR Neumark, DM TI Vibrationally reserved photoelectron spectroscopy of silicon cluster anions Si-n(-) (n=3-7) SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID CAS SCF/CI CALCULATIONS; ELECTRONIC-STRUCTURES; GROUND-STATE; SPECTRA; SI-3; SI3; PHOTODETACHMENT; SEMICONDUCTOR; STABILITIES; GERMANIUM AB Photoelectron spectra of Si-n(-) (n=3-7) have been measured at several photodetachment energies. The anions were created using a pulsed discharge source, resulting in considerably colder clusters than in earlier work. As a result, vibrationally resolved spectra were obtained for larger clusters and more electronic states than in previous studies of these species, leading to more accurate electron affinities, term energies, and vibrational frequencies for the ground and excited electronic states of the neutral clusters. The assignments of excited states were aided by ab initio calculations and photoelectron angular distributions. (C) 1998 American Institute of Physics. [S0021-9606(98)02703-2]. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Xu, CS (reprint author), Lam Res Corp, 77 W Montague Expressway, Milpitas, CA 95035 USA. RI Neumark, Daniel/B-9551-2009 OI Neumark, Daniel/0000-0002-3762-9473 NR 31 TC 133 Z9 137 U1 1 U2 14 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1998 VL 108 IS 4 BP 1395 EP 1406 DI 10.1063/1.475511 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR488 UT WOS:000071500300014 ER PT J AU Bent, G Krstic, PS Schultz, DR AF Bent, G Krstic, PS Schultz, DR TI The multielectron, hidden crossings method for inelastic processes in slow ion/atom-atom collisions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID HARTREE-FOCK SCHEME; ELECTRON-CAPTURE; GROUND-STATE; SEMICLASSICAL THEORY; HYDROGENIC IONS; IONIZATION; HELIUM; PROTONS; ANTIPROTONS; EXCITATION AB A new method is described for studying collision dynamics in slow ion/atom-atom collisions. It is a generalization of the single-electron, two-center hidden crossings method to multielectron systems. This approach derives from the analytic properties of energy surfaces and wave functions of the adiabatic electronic Hamiltonian when the internuclear distance is extended into the complex plane. The collision dynamics in the adiabatic limit is determined by the topology of the unique multivalued electronic energy surface, particularly by its singular points, the square-root branch points. The surfaces described here have been studied using a complex version of the unrestricted Hartree-Fock and configuration interaction method with all single electron excitations, based on a bivariational principle. Although various inelastic processes can be calculated, the method is especially useful for the description of ionization. We have illustrated this through the calculation of cross sections for ionization of helium by proton and antiproton impact, as well as for the collision of two hydrogen atoms. (C) 1998 American Institute of Physics. [S0021-9606(98)02002-9]. C1 Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. RP Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. NR 63 TC 25 Z9 25 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 JAN 22 PY 1998 VL 108 IS 4 BP 1459 EP 1474 DI 10.1063/1.475518 PG 16 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR488 UT WOS:000071500300022 ER PT J AU Garde, S Hummer, G Paulaitis, ME AF Garde, S Hummer, G Paulaitis, ME TI Free energy of hydration of a molecular ionic solute: Tetramethylammonium ion SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID OF-MEAN-FORCE; COMPUTER-SIMULATIONS; ELECTRON-TRANSFER; POLAR-SOLVENTS; MONTE-CARLO; BORN MODEL; WATER; SOLVATION; POTENTIALS; THERMODYNAMICS AB We have performed Monte Carlo simulations of the tetramethylammonium ion, hydrated by 256 simple point charge (SPC) water molecules, as a function of total charge on the ion. The total charge was varied between -3e to +3e at intervals of 1e, and was distributed equally on the four methyl sites on the ion. Derivatives of the foe energy with respect to charge were related to the fluctuations in the ion-water interaction energies using a cumulant expansion. This derivative information for the different charge states was found to give an accurate description of the free energy of hydration. The calculated hydration foe energies were also found to be only weakly dependent on system size and the method used for calculating the electrostatic interactions (Ewald summation or generalized reaction field), when finite system size corrections are applied. The quadratic charge dependence was obtained for the free energy of hydration for both positive and negative ions as expected from the Born model. The hydration is, however, asymmetric. Negative ions are more favorably hydrated compared to positive ions. We relate this asymmetry of hydration to water structure; that is, to differences in the water oxygen and water hydrogen density profiles surrounding positive and negative ions. Another manifestation of this asymmetry is seen in the positive electrostatic potential at the center of methyl sites in the uncharged state of the tetramethylammonium solute. (C) 1998 American Institute of Physics. C1 Johns Hopkins Univ, Dept Chem Engn, Baltimore, MD 21218 USA. Univ Delaware, Ctr Mol & Engn Thermodynam, Dept Chem Engn, Newark, DE 19716 USA. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Garde, S (reprint author), Johns Hopkins Univ, Dept Chem Engn, Baltimore, MD 21218 USA. EM garde@lanl.gov; michaelp@jhu.edu RI Garde, Shekhar/C-3060-2008; Hummer, Gerhard/A-2546-2013 OI Hummer, Gerhard/0000-0001-7768-746X NR 49 TC 54 Z9 54 U1 0 U2 11 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1998 VL 108 IS 4 BP 1552 EP 1561 DI 10.1063/1.475526 PG 10 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR488 UT WOS:000071500300031 ER PT J AU Imai, M Kato, T Schneider, D AF Imai, M Kato, T Schneider, D TI Coarsening of cubic lattice domains observed in a nonionic surfactant system SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GRAIN-GROWTH AB We have investigated the coarsening process of domains having a cubic lattice in a nonionic surfactant system using a time-resolved small-angle neutron scattering technique, The obtained time evolution of scattering patterns showed growing large domains with strong diffraction intensity fluctuation and shrinking small domains obeying dynamical scaling law, This bimodal domain coarsening suggests an anomalous domain coarsening, During the coarsening the cubic lattice was distorted about 10%, which is probably due to the adjustment of the adjacent lattice at boundary. This elasticity effect probably brings about the observed anomalous domain coarsening. (C) 1998 American Institute of Physics. [S0021-9606(98)51804-1]. C1 Univ Tokyo, Inst Solid State Phys, Tokai, Ibaraki 31911, Japan. Tokyo Metropolitan Univ, Fac Sci, Tokyo 19203, Japan. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Imai, M (reprint author), Univ Tokyo, Inst Solid State Phys, Tokai, Ibaraki 31911, Japan. NR 16 TC 6 Z9 6 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 22 PY 1998 VL 108 IS 4 BP 1710 EP 1714 DI 10.1063/1.475542 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR488 UT WOS:000071500300048 ER PT J AU Karpovich, DS Ray, D AF Karpovich, DS Ray, D TI Adsorption of dimethyl sulfoxide to the liquid/vapor interface of water and the thermochemistry of transport across the interface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Letter ID AQUEOUS SURFACES; MOLECULES; SO2 AB Resonantly enhanced surface second harmonic generation has been used to measure the adsorption isotherm of dimethyl sulfoxide (DMSO) at the liquid/vapor interface of water. The Langmuir model of interfacial adsorption was used to model the data allowing determination of -11.8 (sigma = 1.2) kJ/mol for the Gibbs free energy of adsorption of DMSO to the liquid/vapor interface of water at 293 K. This value of the adsorption energy is combined with data obtained from the literature to yield a complete thermodynamic characterization of a model potential energy surface for the transport of DMSO across the liquid/vapor interface of water. Some implications of this potential energy surface on the kinetics of mass transport are presented. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Ray, D (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. NR 22 TC 28 Z9 28 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 22 PY 1998 VL 102 IS 4 BP 649 EP 652 DI 10.1021/jp972323w PG 4 WC Chemistry, Physical SC Chemistry GA YV235 UT WOS:000071802900001 ER PT J AU Iedema, MJ Kizhakevariam, N Cowin, JP AF Iedema, MJ Kizhakevariam, N Cowin, JP TI Mixed oxide surfaces: Ultrathin films of CaxMg(1-x)O SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID MGO FILMS; CA SEGREGATION; ADSORPTION; SPECTROSCOPY; WATER; TEMPERATURE; MGO(001); MGO(100); MO(100); GROWTH AB Nonstochiometric mixed oxides are often of interest for their novel catalytic or material properties yet are often difficult to synthesize in easily characterizable forms. We report on the use of low-temperature epitaxy of Ca and Mg under oxidizing conditions to yield mixed thin film oxides. Low-energy electron diffraction showed that the mixed oxides grew as single crystals over a wide range of compositions. We compare the water adsorption characteristics of the mixed oxide to that of CaO and MgO and find that the mixed oxide behavior is not a linear combination of the two pure oxide systems. The thermal stability of the mixed oxide film was checked by Anger electron ratios for an oxide-oxide "sandwich" after various "flash" anneals. This and water adsorption results suggest intimate atomic-scale mixing exists until flashed above 1100 K. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. Varian Ion Implant Syst, Portland, OR 97223 USA. RP Iedema, MJ (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, Box 999 M-S K8-88, Richland, WA 99352 USA. NR 28 TC 11 Z9 11 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 22 PY 1998 VL 102 IS 4 BP 693 EP 700 DI 10.1021/jp973169g PG 8 WC Chemistry, Physical SC Chemistry GA YV235 UT WOS:000071802900008 ER PT J AU Ackerbauer, P Balin, DV Baturin, VM Beer, GA Breunlich, WH Case, T Crowe, K Daniel, H Deutsch, J Govaerts, J Grigoriev, YS Hartmann, FJ Kammel, P King, R Lauss, B Maev, EM Markushin, VE Marton, J Muhlbauer, M Petitjean, C Petitjean, T Petrov, GE Prieels, R Prymas, W Schott, W Semenchuk, GG Smirenin, YV Vorobyov, AA Voropaev, NI Wojciechowski, P AF Ackerbauer, P Balin, DV Baturin, VM Beer, GA Breunlich, WH Case, T Crowe, K Daniel, H Deutsch, J Govaerts, J Grigoriev, YS Hartmann, FJ Kammel, P King, R Lauss, B Maev, EM Markushin, VE Marton, J Muhlbauer, M Petitjean, C Petitjean, T Petrov, GE Prieels, R Prymas, W Schott, W Semenchuk, GG Smirenin, YV Vorobyov, AA Voropaev, NI Wojciechowski, P TI A precision measurement of nuclear muon capture on He-3 SO PHYSICS LETTERS B LA English DT Article DE muon; capture; helium; triton; pseudoscalar form factor ID HELIUM AB The muon capture rate in the reaction mu(-)+He-3-->nu(mu)+H-3 has been measured at PSI using a modular high pressure ionization chamber. The rate corresponding to statistical hyperfine population of the mu(3)He atom is (1496.0+/-4.0)s(-1). This result confirms the PCAC prediction for the pseudoscalar form factors of the He-3-H-3 system and the nucleon. (C) 1998 Elsevier Science B.V. C1 Austrian Acad Sci, Inst Medium Energy Phys, A-1090 Vienna, Austria. Petersburg Nucl Phys Inst, Gatchina 188350, Russia. Univ Catholique Louvain, B-1348 Louvain, Belgium. Paul Scherrer Inst, CH-5232 Villigen, Switzerland. Tech Univ Munich, D-85747 Garching, Germany. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. IV Kurchatov Atom Energy Inst, Moscow 123182, Russia. Univ Victoria, Victoria, BC V8W 2Y2, Canada. RP Ackerbauer, P (reprint author), Austrian Acad Sci, Inst Medium Energy Phys, A-1090 Vienna, Austria. EM petitjean@psi.ch RI Marton, Johann/H-2668-2012 OI Marton, Johann/0000-0001-5139-7720 NR 24 TC 60 Z9 60 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 22 PY 1998 VL 417 IS 3-4 BP 224 EP 232 DI 10.1016/S0370-2693(97)01382-8 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZF058 UT WOS:000072858500003 ER PT J AU Jadach, S Placzek, W Skrzypek, M Ward, BFL Was, Z AF Jadach, S Placzek, W Skrzypek, M Ward, BFL Was, Z TI Exact O(alpha) gauge invariant YFS exponentiated Monte Carlo for (un)stable W+W- production at and beyond LEP2 energies SO PHYSICS LETTERS B LA English DT Article ID W-PAIR PRODUCTION; ELECTROWEAK RADIATIVE-CORRECTIONS; HEAVY UNSTABLE PARTICLES; ONE-LOOP; CROSS-SECTION; VECTOR BOSON; E+E-->W+W; DECAY; APPROXIMATION; PROGRAM AB We realize, by Monte Carlo event generator methods, the exact O(alpha) YFS exponentiated calculation of e(+)e(-) -->, W+W-(-->f(1) (f) over bar(1)' + (f) over bar(2)f(2)') at and beyond LEP2 energies, where the left-handed parts of f(i) and f(i)' are the respective upper and lower components of an SU2L doublet, i = 1, 2, Our calculation is gauge invariant from the standpoint of its radiative effects and the respective YFS Monte Carlo event generator YFSWW3, wherein both Standard Model and anomalous triple gauge boson couplings are allowed, generates n(gamma) radiation both from the initial state and from the final W+W-. Sample Monte Carlo data are illustrated. (C) 1998 Elsevier Science B.V. C1 Inst Nucl Phys, Krakow, Poland. CERN, Div Theory, CH-1211 Geneva 23, Switzerland. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Jadach, S (reprint author), Inst Nucl Phys, Ul Kawiory 26A, Krakow, Poland. NR 46 TC 65 Z9 65 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 22 PY 1998 VL 417 IS 3-4 BP 326 EP 336 DI 10.1016/S0370-2693(97)01253-7 PG 11 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA ZF058 UT WOS:000072858500017 ER PT J AU Chen, LH Lucia, L Whitten, DG AF Chen, LH Lucia, L Whitten, DG TI Cooperative electron transfer fragmentation reactions. Amplification of a photoreaction through a tandem chain fragmentation of acceptor and donor pinacols SO JOURNAL OF THE AMERICAN CHEMICAL SOCIETY LA English DT Article ID RADICAL-ION-PAIRS; CATION RADICALS; CLEAVAGE; MECHANISM C1 Univ Rochester, Dept Chem, Rochester, NY 14627 USA. RP Whitten, DG (reprint author), Univ Calif Los Alamos Natl Lab, CST-1 MS J565, Los Alamos, NM 87545 USA. NR 15 TC 9 Z9 9 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0002-7863 J9 J AM CHEM SOC JI J. Am. Chem. Soc. PD JAN 21 PY 1998 VL 120 IS 2 BP 439 EP 440 DI 10.1021/ja9718174 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA YT612 UT WOS:000071624500032 ER PT J AU Neuffer, D Van Ginneken, A AF Neuffer, D Van Ginneken, A TI Simulation studies of ionization cooling SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID PARTICLES AB A mu(+)-mu(-) collider relies on ionization cooling to compress the beam phase-space volume for maximal luminosity. In this paper we present simulations of ionization cooling which explore the various conditions needed for compression to collider conditions. These simulations are based on a maximally complete model of muon-atom interactions, including accurate distributions of multiple scattering and energy straggling effects. Particular cases such as cooling in low-Z absorbers, in active lenses, within solenoids, as well as the use of wedge absorbers for phase space exchange and the energy dependence of the cooling process, are explored. Constraints and guidelines for the development of complete cooling scenarios are discussed. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. RP Neuffer, D (reprint author), Fermi Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 16 TC 1 Z9 1 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 1998 VL 403 IS 1 BP 1 EP 21 DI 10.1016/S0168-9002(97)01070-X PG 21 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU461 UT WOS:000071720100001 ER PT J AU Ajaltouni, Z Albiol, F Alifanov, A Amaral, P Amelin, D Amorim, A Anderson, K Angelini, C Agnvall, S Antola, A Astesan, F Astvatsaturov, A Autiero, D Badaud, F Barreira, G Benetta, R Berglund, S Blanchot, G Blucher, E Blaj, C Bodo, P Bogush, A Bohm, C Boldea, V Borisov, O Bosman, M Bouhemaid, N Brette, P Breveglieri, L Bromberg, C Brossard, M Budagov, J Caloba, L Carvalho, J Casado, P Castera, A Cattaneo, PW Cavalli-Sforza, M Cavasinni, V Chadelas, R Chevaleyre, JC Chirikov-Zorin, I Chlachidze, G Cobal, M Cogswell, F Colaco, F Constantinescu, S Costanzo, D Crouau, M Dadda, L Daudon, F David, J David, M Davidek, T Dawson, J De, K Del Prete, T De Santo, A Di Girolamo, B Dita, S Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Efthymiopoulos, I Engstrom, M Errede, D Errede, S Evans, H Fenyuk, A Ferrer, A Fristedt, A Flaminio, V Gallas, E Gaspar, M Gildemeister, O Givoletto, M Glagolev, V Goggi, VG Gomes, A Gong, S Gouz, Y Grabsky, V Grieco, M Hakopian, H Haney, M Hansen, M Hellman, S Henriques, A Hentzell, H Holmberg, T Holmgren, S Honore, PF Huston, J Ivanyushenkov, Y Jon-And, K Juste, A Kakurin, S Karapetian, G Karyukhin, A Kerek Khokhlov, Y Kopikov, S Kostrikov, M Kostyukhin, V Kukhtin, V Kulchitsky, Y Kurzbauer, W Lami, S Landi, C Lapin, V Lazzeroni, C Lebedev, A Leitner, R Li, J Lippi, M Ledortz, O Lofstedt, B Lomakin, Y Lomakina, O Lokajicek, M Lund-Jensen, B Maio, A Malyukov, S Mariani, R Marroquin, F Martins, JP Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mnatsakanian, E Montarou, G Motto, S Muanza, GS Nemecek, S Nessi, M Odmark, A Onofre, A Orteu, S Padilla, C Pallin, D Pantea, D Patriarca, J Pereira, A Perlas, JA Persson, ST Petit, P Pilcher, J Pinhao, J Poggioli, L Poirot, S Polesello, G Price, L Proudfoot, J Pukhov, O Reinmuth, G Renzoni, G Richards, R Riu, I Romanov, V Ronceux, B Rumyantsev, V Russakovich, N Sami, M Sanders, H Santos, J Savoy-Navarro, A Sawyer, L Says, LP Schwemling, P Seixas, JM Sellden, B Semenov, A Shchelchkov, A Shochet, M Simaitis, V Sissakian, A Solodkov, A Solovianov, O Sonderegger, P Soustruznik, K Stanek, R Starchenko, E Stefanelli, R Stephens, R Suk, M Sundblad, R Svensson, C Tang, F Tardell, S Tas, P Teubert, F Thaler, J Tokar, S Topilin, N Trka, Z Turcot, A Turcotte, M Valkar, S Varandas, MJ Vartapetian, A Vazeille, F Vinogradov, V Vivaldi, F Vorozhtsov, S Wagner, D White, A Wolters, H Yamdagni, N Yarygin, G Yosef, C Yuan, J Zaitsev, A Zdrazil, M AF Ajaltouni, Z Albiol, F Alifanov, A Amaral, P Amelin, D Amorim, A Anderson, K Angelini, C Agnvall, S Antola, A Astesan, F Astvatsaturov, A Autiero, D Badaud, F Barreira, G Benetta, R Berglund, S Blanchot, G Blucher, E Blaj, C Bodo, P Bogush, A Bohm, C Boldea, V Borisov, O Bosman, M Bouhemaid, N Brette, P Breveglieri, L Bromberg, C Brossard, M Budagov, J Caloba, L Carvalho, J Casado, P Castera, A Cattaneo, PW Cavalli-Sforza, M Cavasinni, V Chadelas, R Chevaleyre, JC Chirikov-Zorin, I Chlachidze, G Cobal, M Cogswell, F Colaco, F Constantinescu, S Costanzo, D Crouau, M Dadda, L Daudon, F David, J David, M Davidek, T Dawson, J De, K Del Prete, T De Santo, A Di Girolamo, B Dita, S Dolejsi, J Dolezal, Z Downing, R Dugne, JJ Efthymiopoulos, I Engstrom, M Errede, D Errede, S Evans, H Fenyuk, A Ferrer, A Fristedt, A Flaminio, V Gallas, E Gaspar, M Gildemeister, O Givoletto, M Glagolev, V Goggi, VG Gomes, A Gong, S Gouz, Y Grabsky, V Grieco, M Hakopian, H Haney, M Hansen, M Hellman, S Henriques, A Hentzell, H Holmberg, T Holmgren, S Honore, PF Huston, J Ivanyushenkov, Y Jon-And, K Juste, A Kakurin, S Karapetian, G Karyukhin, A Kerek Khokhlov, Y Kopikov, S Kostrikov, M Kostyukhin, V Kukhtin, V Kulchitsky, Y Kurzbauer, W Lami, S Landi, C Lapin, V Lazzeroni, C Lebedev, A Leitner, R Li, J Lippi, M Ledortz, O Lofstedt, B Lomakin, Y Lomakina, O Lokajicek, M Lund-Jensen, B Maio, A Malyukov, S Mariani, R Marroquin, F Martins, JP Mazzoni, E Merritt, F Michel, B Miller, R Minashvili, I Miralles, L Mnatsakanian, E Montarou, G Motto, S Muanza, GS Nemecek, S Nessi, M Odmark, A Onofre, A Orteu, S Padilla, C Pallin, D Pantea, D Patriarca, J Pereira, A Perlas, JA Persson, ST Petit, P Pilcher, J Pinhao, J Poggioli, L Poirot, S Polesello, G Price, L Proudfoot, J Pukhov, O Reinmuth, G Renzoni, G Richards, R Riu, I Romanov, V Ronceux, B Rumyantsev, V Russakovich, N Sami, M Sanders, H Santos, J Savoy-Navarro, A Sawyer, L Says, LP Schwemling, P Seixas, JM Sellden, B Semenov, A Shchelchkov, A Shochet, M Simaitis, V Sissakian, A Solodkov, A Solovianov, O Sonderegger, P Soustruznik, K Stanek, R Starchenko, E Stefanelli, R Stephens, R Suk, M Sundblad, R Svensson, C Tang, F Tardell, S Tas, P Teubert, F Thaler, J Tokar, S Topilin, N Trka, Z Turcot, A Turcotte, M Valkar, S Varandas, MJ Vartapetian, A Vazeille, F Vinogradov, V Vivaldi, F Vorozhtsov, S Wagner, D White, A Wolters, H Yamdagni, N Yarygin, G Yosef, C Yuan, J Zaitsev, A Zdrazil, M TI Evaluation of Fermi read-out of the Atlas Tilecal prototype SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article DE calorimetry; signal processing; read-out electronics ID CALORIMETER; MICROSYSTEM; FIR AB Prototypes of the FERMI system have been used to read out a prototype of the ATLAS hadron calorimeter in a beam test at the CERN SPS. The FERMI read-out system, using a compressor and a sampling ADC, is compared to a standard charge integrating read-out by measuring the energy resolution of the calorimeter separately with the two systems on the same events. Signal processing techniques have been designed to optimize the treatment of FERMI data. The resulting energy resolution is better than the one obtained with the standard read-out. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Pavia, I-27100 Pavia, Italy. Ist Nazl Fis Nucl, I-27100 Pavia, Italy. Univ Blaise Pascal, CNRS, IN2P3, LPC Clermont Ferrand, Clermont Ferrand, France. IFIC, Valencia, Spain. Inst Phys ASB, Minsk, Byelarus. LIP, P-1000 Lisbon, Portugal. Univ Lisbon, FCUL, P-1699 Lisbon, Portugal. Univ Coimbra, LIP, P-3000 Coimbra, Portugal. Univ Coimbra, FCTUC, P-3000 Coimbra, Portugal. Inst High Energy Phys, Protvino, Russia. Univ Chicago, Chicago, IL 60637 USA. Ist Nazl Fis Nucl, Pisa, Italy. Univ Pisa, I-56100 Pisa, Italy. Stockholm Univ, S-10691 Stockholm, Sweden. Politecn Milan, Pavia, Italy. Univ Paris 06, LPNHE, Paris, France. Univ Paris 07, LPNHE, Paris, France. JINR, Dubna, Russia. CERN, Geneva, Switzerland. Univ Autonoma Barcelona, Inst Fis Altes Energies, Barcelona, Spain. Inst Atom Phys, R-76900 Bucharest, Romania. Linkoping Univ, Ind Microelect Ctr, S-58183 Linkoping, Sweden. Michigan State Univ, E Lansing, MI 48824 USA. UFRJ, COPPE, EE, Rio De Janeiro, Brazil. Univ Illinois, Chicago, IL 60680 USA. Charles Univ, Prague, Czech Republic. Argonne Natl Lab, Argonne, IL 60439 USA. Univ Texas, Arlington, TX 76019 USA. CAEN SPA, Viareggio, Italy. Yerevan Phys Inst, Yerevan 375036, Armenia. SiCon AB, Linkoping, Sweden. Royal Inst Technol, S-10044 Stockholm, Sweden. Acad Sci Czech Republ, Prague, Czech Republic. CAEN Microelect, Pisa, Italy. Linkoping Univ, S-58183 Linkoping, Sweden. Comenius Univ, Bratislava, Slovakia. RP Cattaneo, PW (reprint author), Univ Pavia, Via Palestro 3, I-27100 Pavia, Italy. EM cattaneo@pv.infn.it RI Solodkov, Alexander/B-8623-2017; David, Mario/C-4664-2012; Zaitsev, Alexandre/B-8989-2017; Wolters, Helmut/M-4154-2013; De, Kaushik/N-1953-2013; Nemecek, Stanislav/G-5931-2014; Bosman, Martine/J-9917-2014; Cavalli-Sforza, Matteo/H-7102-2015; Ferrer, Antonio/H-2942-2015; Carvalho, Joao/M-4060-2013; Karyukhin, Andrey/J-3904-2014; Juste, Aurelio/I-2531-2015; OI Solodkov, Alexander/0000-0002-2737-8674; Zaitsev, Alexandre/0000-0002-4961-8368; Gomes, Agostinho/0000-0002-5940-9893; Sawyer, Lee/0000-0001-8295-0605; Wolters, Helmut/0000-0002-9588-1773; De, Kaushik/0000-0002-5647-4489; Bosman, Martine/0000-0002-7290-643X; Ferrer, Antonio/0000-0003-0532-711X; Carvalho, Joao/0000-0002-3015-7821; Barreira, Gaspar/0000-0001-6373-9441; Cattaneo, Paolo Walter/0000-0001-6877-6882; Karyukhin, Andrey/0000-0001-9087-4315; Maio, Amelia/0000-0001-9099-0009; Lami, Stefano/0000-0001-9492-0147; Juste, Aurelio/0000-0002-1558-3291; Amorim, Antonio/0000-0003-0638-2321; Evans, Harold/0000-0003-2183-3127; Colomer, Kiko Albiol/0000-0002-3824-2246 NR 19 TC 1 Z9 1 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 1998 VL 403 IS 1 BP 98 EP 114 DI 10.1016/S0168-9002(97)01086-3 PG 17 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU461 UT WOS:000071720100007 ER PT J AU Philhour, B Boggs, SE Primbsch, JH Slassi-Sennou, AS Lin, RP Feffer, PT McBride, S Goulding, FS Madden, NW Pehl, RH AF Philhour, B Boggs, SE Primbsch, JH Slassi-Sennou, AS Lin, RP Feffer, PT McBride, S Goulding, FS Madden, NW Pehl, RH TI Simulations of pulse shape discrimination (PSD) techniques for background reduction in germanium detectors SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article ID GAMMA-RAY SPECTROSCOPY; GE; SPECTROMETERS AB For modern, actively shielded, narrow aperture germanium detector (GeD) spectrometers at balloon or spacecraft altitudes, the continuum background in the 0.2 to 2 MeV energy range is dominated by the beta(-) decay of radioactive nuclei produced by the interaction of cosmic rays and secondary protons and neutrons within the detector. PSD techniques distinguish single-sire (primarily beta(-)-decay) from multiple-site (primarily photon) events by analyzing the shape of the current pulse formed when the electrons and holes resulting from these energy depositions propagate through the detector. Through numerical simulation of the charge collection process, we demonstrate that the effectiveness of PSD can be enhanced by optimizing detector geometry and external electronics. In particular, PSD results for closed-end coaxial detectors with standard (1.2 cm effective diameter) and narrow (0.6 cm diameter) inner bore, and for a true coaxial narrow-bore detector, are presented. With a newly developed PSD algorithm, improvements in sensitivity at 1 MeV of factors of 2.8 and 3.6 for the standard-bore and narrow-bore closed-end coaxial detectors, respectively, and 4.0 for the true coaxial detector, are predicted. (C) 1998 Elsevier Science B.V. All rights reserved. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Slassi-Sennou, AS (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Boggs, Steven/E-4170-2015 OI Boggs, Steven/0000-0001-9567-4224 NR 14 TC 14 Z9 14 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 21 PY 1998 VL 403 IS 1 BP 136 EP 150 DI 10.1016/S0168-9002(97)01071-1 PG 15 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU461 UT WOS:000071720100009 ER PT J AU Fernandez, A Phillion, DW AF Fernandez, A Phillion, DW TI Effects of phase shifts on four-beam interference patterns SO APPLIED OPTICS LA English DT Article ID INTERFEROMETRIC LITHOGRAPHY; ARRAYS AB An analysis of the effects of relative phase changes on the interference pattern formed by the coherent addition of four plane waves is presented. We focus on the configuration in which four plane waves converge at equal angles along two orthogonal planes, an arrangement that is potentially useful for Printing arrays of microstructures in resist. We show that, depending on the set of polarization vectors chosen, the shape of the interference pattern is a strong function of the phase difference between each pair of beams. If all the beams have the same phase constant, an intensity distribution that is perfectly modulated and that exhibits strong contrast is produced. However, if the phase constant of any one of the beams is shifted by pi from this condition, a pattern with degraded modulation and significantly weaker contrast is formed. We discuss the implication of these results on lithographic applications of multiple-beam patterns. Further, we show that the sensitivity to phase is a general property of all interference patterns formed by four or more intersecting coherent wave fronts that have collinear electric-field components. (C) 1998 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Fernandez, A (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 8 TC 42 Z9 43 U1 1 U2 5 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 20 PY 1998 VL 37 IS 3 BP 473 EP 478 DI 10.1364/AO.37.000473 PG 6 WC Optics SC Optics GA YR499 UT WOS:000071501400011 PM 18268609 ER PT J AU Milam, D AF Milam, D TI Review and assessment of measured values of the nonlinear refractive-index coefficient of fused silica SO APPLIED OPTICS LA English DT Article ID PHASE-MODULATION; DISPERSION; FIBERS; PULSES; LIGHT; GLASS AB The literature describes more than 30 measurements. at wavelengths between 249 and 1550 nm, of the absolute value of the nonlinear refractive-index coefficient of fused silica. Results of these experiments were assessed and best currently available values were selected for the wavelengths of 351, 527, and 1053 nm. The best values are (3.6 +/- 0.64) x 10(-16) cm(2)/W at 351 nm, (3.0 +/- 0.35) x 10(-16) cm(2)/W at 527 nm, and (2.74 +/- 0.17) x 10(-16) cm(2)/W at 1053 nm. (C) 1998 Optical Society of America. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Milam, D (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 26 TC 179 Z9 182 U1 3 U2 24 PU OPTICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE NW, WASHINGTON, DC 20036 USA SN 0003-6935 J9 APPL OPTICS JI Appl. Optics PD JAN 20 PY 1998 VL 37 IS 3 BP 546 EP 550 DI 10.1364/AO.37.000546 PG 5 WC Optics SC Optics GA YR499 UT WOS:000071501400025 PM 18268623 ER PT J AU Athreya, RM Kapahi, VK McCarthy, PJ van Breugel, W AF Athreya, RM Kapahi, VK McCarthy, PJ van Breugel, W TI Large rotation measures in radio galaxies at z > 2 SO ASTRONOMY & ASTROPHYSICS LA English DT Article DE galaxies : magnetic fields; radio continuum : galaxies; cosmology : observations ID GALACTIC MAGNETIC-FIELD; SMALL-SCALE VARIATIONS; LY-ALPHA SYSTEMS; FARADAY-ROTATION; HIGH-REDSHIFT; VLA OBSERVATIONS; COOLING FLOWS; CLUSTER; SPECTRUM; LOBES AB We have carried out multifrequency radio polarisation imaging of a sample of 15 radio galaxies at z > 2 from the MRC/1Jy sample using the VLA. We report here the discovery of large rotation measures (RM) in a considerable fraction of the high redshift radio galaxies. Using the difference between the RM values of the two radio lobes in each source and statistical arguments, we show that the Faraday screens responsible for the RMs are most likely to be in the vicinity of the radio sources themselves. Four of the 15 galaxies show intrinsic (redshift corrected) RMs in excess of 1000 rad m(-2) with the highest value of similar to 6000 rad m(-2) in 1138-262 at z = 2.17. These observations suggest that the environments of the radio galaxies at z > 2 have micro gauss magnetic fields correlated over many kpc (>5-10), at least. We have discussed the problems due to the short time available at those redshifts for the various mechanisms, which are believed to generate and correlate strong magnetic fields on large scales, to operate. In particular, we argue that, unlike at low redshifts, cluster cooling flows are unlikely to have a role in forming deep Faraday screens at high redshifts. It is not clear if the dynamo mechanism is capable of generating such fields in the ambient medium around the radio sources. It appears plausible that condensates of magnetised plasma (galactic or subgalactic sized) are the deep Faraday screens responsible for the observed RMs. We suggest that plasma clumps of as small as 10(9) M. in the path of the radio jet may generate very large RMs. The presence of such strong and large scale magnetic fields in the medium around the radio sources at such early epochs poses a considerable challenge to models of the origin of magnetic fields in the Universe. C1 Natl Ctr Radio Astrophys, Pune 411007, Maharashtra, India. Carnegie Inst Washington Observ, Pasadena, CA 91107 USA. Univ Calif Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. RP Athreya, RM (reprint author), Natl Ctr Radio Astrophys, POB 3,Pune Univ Campus, Pune 411007, Maharashtra, India. NR 48 TC 60 Z9 60 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 JAN 20 PY 1998 VL 329 IS 3 BP 809 EP 820 PG 12 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YT767 UT WOS:000071643000008 ER PT J AU Singh, SB Beard, WA Hingerty, BE Wilson, SH Broyde, S AF Singh, SB Beard, WA Hingerty, BE Wilson, SH Broyde, S TI Interactions between DNA polymerase beta and the major covalent adduct of the carcinogen (+)-anti-benzo[a]pyrene diol epoxide with DNA at a primer-template junction SO BIOCHEMISTRY LA English DT Article ID BASE-EXCISION-REPAIR; ESCHERICHIA-COLI PLASMID; SOLUTION CONFORMATION; OPTICAL ENANTIOMERS; NUCLEAR EXTRACT; BENZOPYRENE; PROTEINS; SITE; 7,8-DIOL-9,10-EPOXIDES; MUTAGENESIS AB A molecular dynamics simulation has been carried out with DNA polymerase beta (beta pol) complexed with a DNA primer-template. The templating guanine at the polymerase active site was covalently modified by the carcinogenic metabolite of benzo[a]pyrene, (+)-anti-benzo[a]pyrene diol epoxide, to form the major (+)-trans-anti-benzo[a]pyrene diol epoxide covalent adduct. Thus, the benzo[a]pyrenyl moiety (BP) is situated in the single-stranded template at the junction between double-and single-stranded DNA. The starting structure was based on the X-ray crystal structure of the rat beta pol primer-template and ddCTP complex [Pelletier, H., Sawaya, M. R., Kumar, A., Wilson, S. H., and Kraut, J. (1994) Science 264, 1891-1903]. During the simulation, the BP and its attached templating guanine rearrange to form a structure in which the BP is closer to parallel with the adjacent base pair. In addition, the templating attached Led guanine is displaced toward the major groove side and access to its Watson-Crick edge is partly obstructed. This structure is stabilized, in part, by new hydrogen bonds between the BP and beta pol Asn(279) and Arg(283). These residues are within hydrogen bonding distance to the incoming ddCTP and templating guanine, respectively, in the crystal structure of the beta pol ternary complex. Site-directed mutagenesis has confirmed their role in dNTP binding, discrimination, and catalytic efficiency [Beard, W. A., Osheroff, W. P., Prasad, ii., Sawaya, M. R., Jaju, M., Wood, T. G., Kraut, J., Kunkel, T. A., and Wilson, S. H. (1996) J. Biol. Chem. 271, 12141-12144]. The predominant biological effect of the BP is DNA polymerase blockage. Consistent with this biological effect, the computed structure suggests the possibility that the BP's main deleterious impact on DNA synthesis might result at least in part from its specific interactions with key polymerase side chains. Moreover, relatively modest movement of BP and its attached guanine, with some concomitant enzyme motion, is necessary to relieve the obstruction and permit the observed rare incorporation of a dATP opposite the guanine lesion. C1 NYU, Dept Biol, New York, NY 10003 USA. Merck & Co Inc, Merck Sharp & Dohme Res Labs, Rahway, NJ 07065 USA. NIEHS, Struct Biol Lab, Res Triangle Pk, NC 27709 USA. Oak Ridge Natl Lab, Div Life Sci, Oak Ridge, TN 37831 USA. RP Broyde, S (reprint author), NYU, Dept Biol, New York, NY 10003 USA. FU NCI NIH HHS [CA-28038]; NCRR NIH HHS [RR-06458] NR 49 TC 15 Z9 15 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 20 PY 1998 VL 37 IS 3 BP 878 EP 884 DI 10.1021/bi9720639 PG 7 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YU546 UT WOS:000071728700012 PM 9454577 ER PT J AU Jessee, JP Fiveland, WA Howell, LH Colella, P Pember, RB AF Jessee, JP Fiveland, WA Howell, LH Colella, P Pember, RB TI An adaptive mesh refinement algorithm for the radiative transport equation SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE radiation; heat transfer; adaptive refinement AB The discrete ordinates form of the radiative transport equation (RTE) is spatially discretized and solved using an adaptive mesh refinement (AMR) algorithm. This technique permits local grid refinement to minimize spatial discretization error of the RTE. An error estimator is applied to define regions for local grid refinement; overlapping refined grids are recursively placed in these regions; and the RTE is then solved over the entire domain. The procedure continues until the spatial discretization error has been reduced to a sufficient level. The following aspects of the algorithm are discussed: error estimation, grid generation, communication between refined levels, and solution sequencing. This initial formulation employs the step scheme and is valid for absorbing and isotropically scattering media in two-dimensional enclosures. The utility of the algorithm is tested by comparing the convergence characteristics and accuracy to those of the standard single-grid algorithm. For two simple benchmark problems, the AMR algorithm maintains the convergence characteristics of the standard single-grid algorithm, but it does not provide any efficiency gains due to a lack of disparate spatial scales. In a third, mon localized problem, however, the AMR algorithm demonstrates significant memory and CPU time reductions. (C) 1998 Academic Press. C1 Babcock & Wilcox, Div Res & Dev, Alliance, OH 44601 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Computat Sci & Engn, Berkeley, CA 94720 USA. RP Jessee, JP (reprint author), Babcock & Wilcox, Div Res & Dev, Alliance, OH 44601 USA. EM patrick.jessee@mcdermott.com NR 16 TC 34 Z9 37 U1 0 U2 5 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 20 PY 1998 VL 139 IS 2 BP 380 EP 398 DI 10.1006/jcph.1997.5870 PG 19 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZB587 UT WOS:000072487500007 ER PT J AU Shashkov, M Swartz, B Wendroff, B AF Shashkov, M Swartz, B Wendroff, B TI Local reconstruction of a vector field from its normal components on the faces of grid cells SO JOURNAL OF COMPUTATIONAL PHYSICS LA English DT Article DE discrete vector fields; reconstruction; non-smooth grids; discrete operators; Lagrangian gas dynamics C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Shashkov, M (reprint author), Univ Calif Los Alamos Natl Lab, T-7,MS-B284, Los Alamos, NM 87545 USA. NR 3 TC 14 Z9 14 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0021-9991 J9 J COMPUT PHYS JI J. Comput. Phys. PD JAN 20 PY 1998 VL 139 IS 2 BP 406 EP 409 DI 10.1006/jcph.1997.5877 PG 4 WC Computer Science, Interdisciplinary Applications; Physics, Mathematical SC Computer Science; Physics GA ZB587 UT WOS:000072487500009 ER PT J AU Romano, P Chen, J Zasadzinski, J AF Romano, P Chen, J Zasadzinski, J TI Josephson and quasiparticle tunneling in SIS junctions of Bi2Sr2CaCu2O8 and Bi2Sr2CuO6 SO PHYSICA C LA English DT Article ID SUPERCONDUCTORS; CUPRATE; NB; SR AB Tunnel junctions have been obtained on Bi2Sr2CaCu2O8 (Bi 2212) and Bi2Sr2CuO6 (Bi 2201) single crystals with T-c values of 86 and 5.5 K respectively. A point contact technique is used with an Au tip, but in certain cases, superconductor-insulator-superconductor (SIS) junctions are obtained between separate pieces of the crystal. These SIS junctions are generally quite stable and in the case of Bi 2212 exhibit well-defined, simultaneous Josephson and quasiparticle tunnel currents, with IcRn = 2-5 mV. The Josephson supercurrent is observed when the junction conductance exceeds a minimum value, G(min), obtained from Ambegaokar-Baratoff theory and the equating of the Josephson coupling energy to k(B)T. For the Bi 2201 crystals the quasiparticle tunneling conductance resembles that of Bi 2212. In particular, a reproducible dip feature is found at eV approximate to 3 Delta in both materials. Relatively high conductance Bi 2201 tunnel junctions (G much greater than G(min)) exhibit a large Josephson current with an IcRn product that is close to the gap voltage 2 Delta/e. (C) 1998 Elsevier Science E.V. C1 IIT, Chicago, IL 60616 USA. Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. Argonne Natl Lab, Div Sci Mat, Argonne, IL 60439 USA. Univ Salerno, Dipartimento Fis, I-84081 Baronissi, Italy. RP Zasadzinski, J (reprint author), IIT, Chicago, IL 60616 USA. NR 18 TC 8 Z9 8 U1 1 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 JAN 20 PY 1998 VL 295 IS 1-2 BP 15 EP 21 DI 10.1016/S0921-4534(97)01667-5 PG 7 WC Physics, Applied SC Physics GA ZE475 UT WOS:000072796600002 ER PT J AU Shyamala, G Yang, X Silberstein, G Barcellos-Hoff, MH Dale, E AF Shyamala, G Yang, X Silberstein, G Barcellos-Hoff, MH Dale, E TI Transgenic mice carrying an imbalance in the native ratio of A to B forms of progesterone receptor exhibit developmental abnormalities in mammary glands SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article ID HUMAN-BREAST; MENSTRUAL-CYCLE; E-CADHERIN; A FORM; MORPHOGENESIS; EXPRESSION; ESTROGEN; GENE; TRANSCRIPTION; SUPERFAMILY AB In this report we document the creation of transgenic mice in which the native ratio of A and B forms of progesterone receptor (PR) has been altered by the introduction of additional A form as transgene. We also show that in these mice there is an aberration in mammary development. In ovariectomized prepubertal PR-A transgenic mice, end buds with unusual morphology persist after ovariectomy, and in young adult nonovariectomized mice, mammary glands have extensive lateral branching, The glands of adult mice also exhibit ductal hyperplasia with a disorganized basement membrane and decreased cell-cell adhesion, features commonly associated with neoplasia, Because progesterone is a mitogenic hormone in mammary glands and PR is required for mammary development, these data provide direct evidence that in vivo a regulated expression of the two isoforms of PR is critical for appropriate cellular response to progesterone and that for mammary glands this may have major implications to carcinogenesis. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Univ Calif Santa Cruz, Dept Biol, Santa Cruz, CA 95064 USA. RP Shyamala, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Bldg 74, Berkeley, CA 94720 USA. EM Shyamala_Harris@lbl.gov FU NCI NIH HHS [CA 66541] NR 35 TC 139 Z9 143 U1 2 U2 4 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JAN 20 PY 1998 VL 95 IS 2 BP 696 EP 701 DI 10.1073/pnas.95.2.696 PG 6 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT462 UT WOS:000071606000048 PM 9435255 ER PT J AU Hui, FYC Eres, G Joy, DC AF Hui, FYC Eres, G Joy, DC TI Factors affecting resolution in scanning electron beam induced patterning of surface adsorption layers SO APPLIED PHYSICS LETTERS LA English DT Article ID TUNNELING MICROSCOPE; OXIDATION; RESIST; LITHOGRAPHY; FABRICATION AB The monoatomic hydride layer on silicon was used as a prototype for resistless electron beam lithography. Arbitrary patterns with linewidths below 60 nm have been achieved. The variation of the linewidth with electron energy, electron dose, and substrate thickness was studied to determine the mechanisms that govern surface hydrogen desorption and subsequent pattern formation. Unlike in resist based lithography, no resolution enhancement was observed with decreasing substrate thickness. The experimental data in combination with Monte Carlo simulations of the backscattered and transmitted electrons suggest that surface hydrogen desorption and pattern formation are not strongly related to the backscattered electrons and the secondary electrons (energies < 50 eV) associated with the backscattered electrons. (C) 1998 American Institute of Physics. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Knoxville, TN 37996 USA. RP Hui, FYC (reprint author), Oak Ridge Natl Lab, Div Solid State, Bldg 3150,MS 6065, Oak Ridge, TN 37831 USA. RI Eres, Gyula/C-4656-2017 OI Eres, Gyula/0000-0003-2690-5214 NR 14 TC 10 Z9 10 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 19 PY 1998 VL 72 IS 3 BP 341 EP 343 DI 10.1063/1.120730 PG 3 WC Physics, Applied SC Physics GA YT041 UT WOS:000071558100025 ER PT J AU Ustinov, VM Weber, ER Ruvimov, S Liliental-Weber, Z Zhukov, AE Egorov, AY Kovsh, AR Tsatsul'nikov, AF Kop'ev, PS AF Ustinov, VM Weber, ER Ruvimov, S Liliental-Weber, Z Zhukov, AE Egorov, AY Kovsh, AR Tsatsul'nikov, AF Kop'ev, PS TI Effect of matrix on InAs self-organized quantum dots on InP substrate SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; TEMPERATURE AB InAs self-organized quantum dots in In0.53Ga0.47As and In0.52Al0.48As matrices have been grown on InP substrates by molecular beam epitaxy. The dot size in InGaAs has been found to be 3-4 times larger, but the areal density about an order of magnitude smaller than that in InAlAs. Low-temperature photoluminescence (PL) of the InAs/InGaAs quantum dots is characterized by a narrow (35 meV) PL line as compared to that of InAs/InAlAs quantum dots (170 meV). Quantum dot formation increases the carrier localization energy as compared to quantum well structures with the same InAs thickness in a similar manner for both InAs/InGaAs and InAs/InAlAs structures, The effect of the barrier band gap on the optical transition energy is qualitatively the same for quantum well and quantum dot structures. The results demonstrate a possibility of controlling the quantum dot emission wavelength by varying the matrix composition. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. AF Ioffe Physicotech Inst, St Petersburg 194021, Russia. RP Ustinov, VM (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM ruv@mhl.lbl.gov RI Liliental-Weber, Zuzanna/H-8006-2012; Egorov, Anton/B-1267-2014; Zhukov, Alexey/A-5523-2014; Tsatsulnikov, Andrey/A-9150-2014; Ustinov, Viktor/J-3545-2013 OI Egorov, Anton/0000-0002-0789-4241; Zhukov, Alexey/0000-0002-4579-0718; NR 10 TC 83 Z9 83 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 19 PY 1998 VL 72 IS 3 BP 362 EP 364 DI 10.1063/1.120737 PG 3 WC Physics, Applied SC Physics GA YT041 UT WOS:000071558100032 ER PT J AU Biswas, R Pan, BC AF Biswas, R Pan, BC TI Microscopic nature of Staebler-Wronski defect formation in amorphous silicon SO APPLIED PHYSICS LETTERS LA English DT Article ID CRYSTALLINE SILICON; MODEL; SI AB Light-induced metastable defects in a-Si:H are proposed to be silicon dangling bonds accompanied by pairs of hydrogen atoms breaking a silicon bond, forming a complex with two Si-H bonds. This supports the model of Branz. These defects are the analog of the H-2* defect in c-Si and their energy correlates with the bond-angle strain. Several features of the annealing are well described by this defect complex. (C) 1998 American Institute of Physics. C1 Iowa State Univ Sci & Technol, Microelect Res Ctr, US Dept Energy, Dept Phys & Astron, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, US Dept Energy, Ames, IA 50011 USA. RP Biswas, R (reprint author), Iowa State Univ Sci & Technol, Microelect Res Ctr, US Dept Energy, Dept Phys & Astron, Ames, IA 50011 USA. EM biswasr@iastate.edu RI Pan, Bicai/A-1235-2010 NR 22 TC 45 Z9 46 U1 0 U2 1 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 19 PY 1998 VL 72 IS 3 BP 371 EP 373 DI 10.1063/1.120740 PG 3 WC Physics, Applied SC Physics GA YT041 UT WOS:000071558100035 ER PT J AU Fullerton, EE Jiang, JS Sowers, CH Pearson, JE Bader, SD AF Fullerton, EE Jiang, JS Sowers, CH Pearson, JE Bader, SD TI Structure and magnetic properties of exchange-spring Sm-Co/Co superlattices SO APPLIED PHYSICS LETTERS LA English DT Article ID 2-PHASE MAGNETS; FILMS AB We present structural and magnetic properties of epitaxial Sm-Co/Co superlattice films prepared via magnetron sputtering. X-ray diffraction and cross-sectional transmission electron microscopy show that the films are structurally coherent, The oriented nature of the interleaved ferromagnetically "hard" and "soft" layers comprising the superlattice provides a realization of the ideal nanostructure of exchange-spring magnets as well as a model system to study layer thickness dependences of the magnetic properties. The superlattice films have an effective fourfold, in-plane magnetic anisotropy. Room-temperature hysteresis loops are relatively square and the demagnetization of the Co is reversible, as expected of exchange-spring magnets with aligned hard magnet layers. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. RP Fullerton, EE (reprint author), IBM Corp, Almaden Res Ctr, San Jose, CA 95120 USA. RI Bader, Samuel/A-2995-2013; Fullerton, Eric/H-8445-2013 OI Fullerton, Eric/0000-0002-4725-9509 NR 9 TC 89 Z9 92 U1 3 U2 25 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 19 PY 1998 VL 72 IS 3 BP 380 EP 382 DI 10.1063/1.120743 PG 3 WC Physics, Applied SC Physics GA YT041 UT WOS:000071558100038 ER PT J AU Gibson, BF Timmermans, RGE AF Gibson, BF Timmermans, RGE TI The pi(+)-emission puzzle in He-4(Lambda) decay SO NUCLEAR PHYSICS A LA English DT Article DE hypernuclei; pi(+) weak decay; strangeness -1 ID HYPERNUCLEI AB We re-examine the puzzling pi(+) emission from the weak decay of He-4(Lambda) and purpose an explanation in terms of a three-body decay similar to of the virtual Sigma(+). Such a resolution of the pi(+) decay puzzle is consistent with the calculated Sigma(+) probability in light Lambda hypernuclei as well as the experimentally observed pi(+) energy spectrum and s-wave angular distribution. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Univ Groningen, Kernfys Versneller Inst, NL-9747 AA Groningen, Netherlands. RP Gibson, BF (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 32 TC 9 Z9 9 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 19 PY 1998 VL 628 IS 3 BP 417 EP 426 DI 10.1016/S0375-9474(97)00642-8 PG 10 WC Physics, Nuclear SC Physics GA ZA968 UT WOS:000072421000005 ER PT J AU Adams, DL Akchurin, N Alexeeva, LV Belikov, NI Bonner, BE Bravar, A Bystricky, J Corcoran, MD Cossairt, JD Cranshaw, J Derevschikov, AA En'yo, H Funahashi, H Goto, Y Grachov, OA Grosnick, DP Hill, DA Iijima, T Imai, K Itow, Y Iwatani, K Kharlov, YV Krueger, KW Kuroda, K Laghai, M Lehar, F de Lesquen, A Lopiano, D Luehring, GC Maki, T Makino, S Masaike, A Matulenko, YA Meschanin, AP Michalowicz, A Miller, DH Miyake, K Nagamine, T Nessi-Tedaldi, F Nessi, M Nguyen, C Nogach, LV Nurushev, SB Ohashi, Y Onel, Y Patalakha, DI Pauletta, G Penzo, A Rappazzo, GF Read, AL Roberts, JB van Rossum, L Rykov, VL Saito, N Salvato, G Schiavon, P Shima, T Skeens, J Solovyanov, VL Spinka, H Stanek, RW Takashima, R Takeutchi, F Tamura, N Tanaka, N Underwood, DG Vasiliev, AN White, JL Yamashita, S Yokosawa, A Yoshida, T Zanetti, A AF Adams, DL Akchurin, N Alexeeva, LV Belikov, NI Bonner, BE Bravar, A Bystricky, J Corcoran, MD Cossairt, JD Cranshaw, J Derevschikov, AA En'yo, H Funahashi, H Goto, Y Grachov, OA Grosnick, DP Hill, DA Iijima, T Imai, K Itow, Y Iwatani, K Kharlov, YV Krueger, KW Kuroda, K Laghai, M Lehar, F de Lesquen, A Lopiano, D Luehring, GC Maki, T Makino, S Masaike, A Matulenko, YA Meschanin, AP Michalowicz, A Miller, DH Miyake, K Nagamine, T Nessi-Tedaldi, F Nessi, M Nguyen, C Nogach, LV Nurushev, SB Ohashi, Y Onel, Y Patalakha, DI Pauletta, G Penzo, A Rappazzo, GF Read, AL Roberts, JB van Rossum, L Rykov, VL Saito, N Salvato, G Schiavon, P Shima, T Skeens, J Solovyanov, VL Spinka, H Stanek, RW Takashima, R Takeutchi, F Tamura, N Tanaka, N Underwood, DG Vasiliev, AN White, JL Yamashita, S Yokosawa, A Yoshida, T Zanetti, A CA FNAL E704 Collaboration TI Measurement of single spin asymmetry in eta-meson production in p up arrow p and (p)over-bar up arrow p interactions in the beam fragmentation region at 200 GeV/c SO NUCLEAR PHYSICS B LA English DT Article DE experimental result; polarization effects; single spin asymmetry; eta-meson production ID HADRON-HADRON COLLISIONS; POLARIZED PROTON-BEAM; ANALYZING POWER; ANTIPROTONS AB We present experimental results on measuring a single spin asymmetry in eta-meson production in the interaction of transversely polarized protons and antiprotons at p(lab) = 200 GeV/c with a proton target in the region 0.2 < x(F) < 0.7 for p up arrow p, 0.3 < x(F) < 0.7 for (p) over bar up arrow p and 0.7 < p(T) < 2.0 GeV/c. A comparison of single spin asymmetries in pi- and eta-meson production is made.(C) 1998 Published by Elsevier Science B.V. C1 Rice Univ, TW Bonner Nucl Lab, Houston, TX 77251 USA. Univ Iowa, Dept Phys, Iowa City, IA 52242 USA. Inst High Energy Phys, Protvino 142284, Russia. Univ Trieste, Dipartimento Fis, I-34100 Trieste, Italy. CEN Saclay, F-91191 Gif Sur Yvette, France. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Kyoto Univ, Dept Phys, Kyoto 606, Japan. Argonne Natl Lab, Argonne, IL 60439 USA. Hiroshima Univ, Higashihiroshima 724, Japan. Phys Particules Lab, F-74017 Annecy Le Vieux, France. Northwestern Univ, Dept Phys, Evanston, IL 60201 USA. Univ Occupat & Environm Hlth, Kitakyushu, Fukuoka 807, Japan. Univ Udine, I-33100 Udine, Italy. Univ Messina, Dipartimento Fis, I-98100 Messina, Italy. Kyoto Univ Educ, Kyoto 612, Japan. Kyoto Sangyo Univ, Kyoto 612, Japan. Okayama Univ, Okayama 700, Japan. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Osaka City Univ, Osaka 558, Japan. RP Adams, DL (reprint author), Rice Univ, TW Bonner Nucl Lab, Houston, TX 77251 USA. RI Zanetti, Anna/I-3893-2012; En'yo, Hideto/B-2440-2015 NR 11 TC 23 Z9 23 U1 0 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 JAN 19 PY 1998 VL 510 IS 1-2 BP 3 EP 11 DI 10.1016/S0550-3213(97)00714-1 PG 9 WC Physics, Particles & Fields SC Physics GA YV360 UT WOS:000071815400001 ER PT J AU Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amidi, E Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK 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 Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P 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 Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A AF Abbott, B Abolins, M Acharya, BS Adam, I Adams, DL Adams, M Ahn, S Aihara, H Alves, GA Amidi, E Amos, N Anderson, EW Astur, R Baarmand, MM Baden, A Balamurali, V Balderston, J Baldin, B Banerjee, S Bantly, J Bartlett, JF Bazizi, K Belyaev, A Beri, SB Bertram, I Bezzubov, VA Bhat, PC Bhatnagar, V Bhattacharjee, M Biswas, N Blazey, G Blessing, S Bloom, P Boehnlein, A Bojko, NI Borcherding, F Boswell, C Brandt, A Brock, R Bross, A Buchholz, D Burtovoi, VS Butler, JM Carvalho, W Casey, D Casilum, Z Castilla-Valdez, H Chakraborty, D Chang, SM Chekulaev, SV Chen, LP Chen, W Choi, S Chopra, S Choudhary, BC Christenson, JH Chung, M Claes, D Clark, AR Cobau, WG Cochran, J Cooper, WE Cretsinger, C Cullen-Vidal, D Cummings, MAC Cutts, D Dahl, OI Davis, K De, K Del Signore, K Demarteau, M Denisov, D Denisov, SP Diehl, HT Diesburg, M Di Loreto, G Draper, P Ducros, Y Dudko, LV Dugad, SR Edmunds, D Ellison, J Elvira, VD Engelmann, R Eno, S Eppley, G Ermolov, P Eroshin, OV Evdokimov, VN Fahland, T Fatyga, M Fatyga, MK 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 Gounder, K Goussiou, A Graf, N Grannis, PD Green, DR Green, J Greenlee, H Grim, G Grinstein, S Grossman, N Grudberg, P Grunendahl, S Guglielmo, G Guida, JA Guida, JM Gupta, A Gurzhiev, SN Gutierrez, P Gutnikov, YE Hadley, NJ Haggerty, H Hagopian, S Hagopian, V Hahn, KS Hall, RE Hanlet, P Hansen, S Hauptman, JM Hedin, D Heinson, AP Heintz, U Hernandez-Montoya, R Heuring, T Hirosky, R Hobbs, JD Hoeneisen, B Hoftun, JS Hsieh, F Hu, T Hu, T Huehn, T Ito, AS James, E Jaques, J Jerger, SA Jesik, R Jiang, JZY Joffe-Minor, T Johns, K Johnson, M Jonckheere, A Jones, M Jostlein, H Jun, SY Jung, CK Kahn, S Kalbfleisch, G Kang, JS Kehoe, R Kelly, ML Kim, CL Kim, SK Klatchko, A Klima, B Klopfenstein, C Klyukhin, VI Kochetkov, VI Kohli, JM Koltick, D Kostritskiy, AV Kotcher, J Kotwal, AV Kourlas, J Kozelov, AV Kozlovski, EA Krane, J Krishnaswamy, MR Krzywdzinski, S Kunori, S Lami, S Lan, H Lander, R Landry, F Landsberg, G Lauer, B Leflat, A Li, H Li, J Li-Demarteau, QZ Lima, JGR Lincoln, D Linn, SL Linnemann, J Lipton, R Liu, Q Liu, YC Lobkowicz, F Loken, SC Lokos, S Lueking, L Lyon, AL Maciel, AKA Madaras, RJ Madden, R Magana-Mendoza, L Mani, S Mao, HS Markeloff, R Marshall, T Martin, MI Mauritz, KM May, B Mayorov, AA McCarthy, R McDonald, J McKibben, T McKinley, J McMahon, T Melanson, HL Merkin, M Merritt, KW Miettinen, H Mincer, A Mishra, CS Mokhov, N Mondal, NK Montgomery, HE Mooney, P da Motta, H Murphy, C Nang, F Narain, M Narasimham, VS Narayanan, A Neal, HA Negret, JP Nemethy, P 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 Piegaia, R Piekarz, H Pischalnikov, Y Podstavkov, VM Pope, BG Prosper, HB Protopopescu, S Qian, J Quintas, PZ Raja, R Rajagopalan, S Ramirez, O Rasmussen, L Reucroft, S Rijssenbeek, M Rockwell, T Roe, NA Rubinov, P Ruchti, R Rutherfoord, J Sanchez-Hernandez, A Santoro, A Sawyer, L Schamberger, RD Schellman, H Sculli, J Shabalina, E Shaffer, C Shankar, HC Shivpuri, RK Shupe, M Singh, H Singh, JB Sirotenko, V Smart, W Smith, RP Snihur, R Snow, GR Snow, J Snyder, S Solomon, J Sood, PM Sosebee, M Sotnikova, N Souza, M Spadafora, AL Stephens, RW Stevenson, ML Stewart, D Stichelbaut, F Stoianova, DA Stoker, D Strauss, M Streets, K Strovink, M Sznajder, A Tamburello, P Tarazi, J Tartaglia, M Thomas, TLT Thompson, J Trippe, TG Tuts, PM Varelas, N Varnes, EW Vititoe, D Volkov, AA Vorobiev, AP Wahl, HD Wang, G Warchol, J Watts, G Wayne, M Weerts, H White, A White, JT Wightman, JA Willis, S Wimpenny, SJ Wirjawan, JVD Womersley, J Won, E Wood, DR Xu, H Yamada, R Yamin, P Yanagisawa, C Yang, J Yasuda, T Yepes, P Yoshikawa, C Youssef, S Yu, J Yu, Y Zhu, ZH Zieminska, D Zieminski, A Zverev, EG Zylberstejn, A TI Experimental search for chargino and neutralino production in supersymmetry models with a light gravitino SO PHYSICAL REVIEW LETTERS LA English DT Article ID FERMILAB TEVATRON; BREAKING; PHYSICS; COLLIDER; DETECTOR; EVENT AB We search for inclusive high E-T diphoton events with large missing transverse energy in p (p) over bar collisions at root s = 1.8 TeV. Such events are expected from pair production of charginos and neutralinos within the framework of the minimal supersymmetric standard model with a light gravitino. No excess of events is observed. In that model, and assuming gaugino mass unification at the GUT scale, we obtain a 95% C.L. exclusion region in the supersymmetry parameter space and lower mass bounds of 150 GeV/c(2) for the lightest chargino and 77 GeV/c(2) for the lightest neutralino. C1 Univ Los Andes, Bogota, Colombia. Univ Arizona, Tucson, AZ 85721 USA. Boston Univ, Boston, MA 02215 USA. Brookhaven Natl Lab, Upton, NY 11973 USA. Brown Univ, Providence, RI 02912 USA. Univ Buenos Aires, Buenos Aires, DF, Argentina. Univ Calif Davis, Davis, CA 95616 USA. Univ Calif Irvine, Irvine, CA 92697 USA. Univ Calif Riverside, Riverside, CA 92521 USA. Ctr Brasileiro Pesquisas Fis, LAFEX, Rio De Janeiro, Brazil. CINVESTAV, Mexico City 14000, DF, Mexico. Columbia Univ, New York, NY 10027 USA. Univ Delhi, Delhi 110007, India. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. Florida State Univ, Tallahassee, FL 32306 USA. Univ Hawaii, Honolulu, HI 96822 USA. Univ Illinois, Chicago, IL 60607 USA. Indiana Univ, Bloomington, IN 47405 USA. Iowa State Univ, Ames, IA 50011 USA. Korea Univ, Seoul 136701, South Korea. Kyungsung Univ, Pusan 608736, South Korea. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Maryland, College Pk, MD 20742 USA. Univ Michigan, Ann Arbor, MI 48109 USA. Michigan State Univ, E Lansing, MI 48824 USA. Moscow State Univ, Moscow, Russia. Univ Nebraska, Lincoln, NE 68588 USA. NYU, New York, NY 10003 USA. Northeastern Univ, Boston, MA 02115 USA. No Illinois Univ, De Kalb, IL 60115 USA. Northwestern Univ, Evanston, IL 60208 USA. Univ Notre Dame, Notre Dame, IN 46556 USA. Univ Oklahoma, Norman, OK 73019 USA. Punjab Univ, Chandigarh 160014, India. Protvino High Energy Phys Inst, Protvino 142284, Russia. Purdue Univ, W Lafayette, IN 47907 USA. Rice Univ, Houston, TX 77005 USA. Univ Estado Rio de Janeiro, Rio De Janeiro, Brazil. Univ Rochester, Rochester, NY 14627 USA. CE Saclay, CEA, DAPNIA, Serv Phys Particules, Gif Sur Yvette, France. Seoul Natl Univ, Seoul, South Korea. SUNY Stony Brook, Stony Brook, NY 11794 USA. Tata Inst Fundamental Res, Colaba 400005, Mumbai, India. Univ Texas, Arlington, TX 76019 USA. Texas A&M Univ, College Stn, TX 77843 USA. RP Abbott, B (reprint author), Univ Los Andes, Bogota, Colombia. RI Alves, Gilvan/C-4007-2013; Peters, Michael/B-4973-2009; Aihara, Hiroaki/F-3854-2010; Shivpuri, R K/A-5848-2010; Gutierrez, Phillip/C-1161-2011; Roe, Natalie/A-8798-2012; 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; Santoro, Alberto/E-7932-2014; Belyaev, Alexander/F-6637-2015; Kim, Sun Kee/G-2042-2015; Chekulaev, Sergey/O-1145-2015; Sznajder, Andre/L-1621-2016 OI Aihara, Hiroaki/0000-0002-1907-5964; Dudko, Lev/0000-0002-4462-3192; Klyukhin, Vyacheslav/0000-0002-8577-6531; De, Kaushik/0000-0002-5647-4489; Belyaev, Alexander/0000-0002-1733-4408; Kim, Sun Kee/0000-0002-0013-0775; Sznajder, Andre/0000-0001-6998-1108 NR 31 TC 44 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 JAN 19 PY 1998 VL 80 IS 3 BP 442 EP 447 DI 10.1103/PhysRevLett.80.442 PG 6 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100005 ER PT J AU Milbrath, BD McIntyre, JI Armstrong, CS Barkhuff, DH Bertozzi, W Chen, JP Dale, D Dodson, G Dow, KA Epstein, MB Farkhondeh, M Finn, JM Gilad, S Jones, MK Joo, K Kelly, JJ Kowalski, S Lourie, RW Madey, R Margaziotis, DJ Markowitz, P Mertz, C Mitchell, J Perdrisat, CF Punjabi, V Qin, L Rutt, PM Sarty, AJ Tieger, D Tschalaer, C Turchinetz, W Ulmer, PE Van Verst, SP Warren, GA Weinstein, LB Woo, RJ AF Milbrath, BD McIntyre, JI Armstrong, CS Barkhuff, DH Bertozzi, W Chen, JP Dale, D Dodson, G Dow, KA Epstein, MB Farkhondeh, M Finn, JM Gilad, S Jones, MK Joo, K Kelly, JJ Kowalski, S Lourie, RW Madey, R Margaziotis, DJ Markowitz, P Mertz, C Mitchell, J Perdrisat, CF Punjabi, V Qin, L Rutt, PM Sarty, AJ Tieger, D Tschalaer, C Turchinetz, W Ulmer, PE Van Verst, SP Warren, GA Weinstein, LB Woo, RJ TI Comparison of polarization observables in electron scattering from the proton and deuteron SO PHYSICAL REVIEW LETTERS LA English DT Article ID ELECTROMAGNETIC FORM-FACTORS; MOMENTUM-TRANSFER; 8.83 (GEV/C)(2); ANALYZING POWER; NEUTRON; NUCLEON; Q(2)=1.75; SYSTEM AB Recoil proton polarization observables were measured for both the p((e) over right arrow,e'(p) over right arrow) and d((e) over right arrow,e'(p) over right arrow)n reactions at two values of Q(2) using a newly commissioned proton focal plane polarimeter at the MIT-Bates Linear Accelerator Center. The hydrogen and deuterium spin-dependent observables D-ll and D-lt, the induced polarization P-n, and the form factor ratio G(E)(P)/G(M)(P) were measured under identical kinematics. The deuterium and hydrogen results are in good agreement with each other and with the plane-wave impulse approximation (PWIA). C1 Univ Virginia, Charlottesville, VA 22901 USA. Coll William & Mary, Williamsburg, VA 23185 USA. MIT, Cambridge, MA 02139 USA. Bates Linear Accelerator Ctr, Cambridge, MA 02139 USA. Calif State Univ Los Angeles, Los Angeles, CA 90032 USA. Univ Maryland, College Pk, MD 20742 USA. Kent State Univ, Kent, OH 44242 USA. Arizona State Univ, Tempe, AZ 85287 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Old Dominion Univ, Norfolk, VA 23259 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. RP Milbrath, BD (reprint author), Eastern Kentucky Univ, Richmond, KY 40475 USA. RI Sarty, Adam/G-2948-2014; McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 37 TC 117 Z9 117 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 19 PY 1998 VL 80 IS 3 BP 452 EP 455 DI 10.1103/PhysRevLett.80.452 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100007 ER PT J AU Woo, RJ Barkhuff, DH Bertozzi, W Chen, JP Dale, D Dodson, G Dow, KA Epstein, MB Farkhondeh, M Finn, JM Gilad, S Jones, MK Joo, K Kelly, JJ Kowalski, S Lourie, RW Madey, R Margaziotis, DJ Markowitz, P McIntyre, JI Mertz, C Milbrath, BD Mitchell, J Perdrisat, CF Punjabi, V Rutt, PM Sarty, AJ Tieger, D Tschalaer, C Turchinetz, W Ulmer, PE Van Verst, SP Vellidis, C Warren, GA Weinstein, L AF Woo, RJ Barkhuff, DH Bertozzi, W Chen, JP Dale, D Dodson, G Dow, KA Epstein, MB Farkhondeh, M Finn, JM Gilad, S Jones, MK Joo, K Kelly, JJ Kowalski, S Lourie, RW Madey, R Margaziotis, DJ Markowitz, P McIntyre, JI Mertz, C Milbrath, BD Mitchell, J Perdrisat, CF Punjabi, V Rutt, PM Sarty, AJ Tieger, D Tschalaer, C Turchinetz, W Ulmer, PE Van Verst, SP Vellidis, C Warren, GA Weinstein, L TI Measurement of the induced proton polarization P-n in the C-12(e,e '(p)over-right-arrow) reaction SO PHYSICAL REVIEW LETTERS LA English DT Article ID SCATTERING; KNOCKOUT AB The first measurements of the induced proton polarization P-n for the C-12(e,e'(p) over right arrow) reaction are reported. The experiment was performed at quasifree kinematics for energy and momentum transfer (w, q) approximate to (294 MeV, 756 MeV/c) and sampled a missing momentum range of 0-250 MeV/c. The induced polarization arises from final-state interactions and for these kinematics is dominated by the real part of the spin-orbit optical potential. The distorted-wave impulse approximation provides good agreement with data fur the 1p(3/2) shelf. The data for the continuum suggest that both the 1s(1/2) shell and underlying l > 1 configurations contribute. C1 Coll William & Mary, Williamsburg, VA 23185 USA. Univ Virginia, Charlottesville, VA 22901 USA. MIT, Cambridge, MA 02139 USA. Bates Linear Accelerator Ctr, Cambridge, MA 02139 USA. Thomas Jefferson Natl Accelerator Facil, Newport News, VA 23606 USA. Calif State Univ Los Angeles, Los Angeles, CA 90032 USA. Univ Maryland, College Pk, MD 20742 USA. Kent State Univ, Kent, OH 44242 USA. Arizona State Univ, Tempe, AZ 85287 USA. Norfolk State Univ, Norfolk, VA 23504 USA. Rutgers State Univ, Piscataway, NJ 08855 USA. Old Dominion Univ, Norfolk, VA 23529 USA. Univ Athens, GR-10679 Athens, Greece. RP Woo, RJ (reprint author), Univ Manitoba, TRIUMF, Vancouver, BC V6T 2A3, Canada. RI Sarty, Adam/G-2948-2014; McIntyre, Justin/P-1346-2014 OI McIntyre, Justin/0000-0002-3706-4310 NR 27 TC 29 Z9 29 U1 0 U2 0 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 19 PY 1998 VL 80 IS 3 BP 456 EP 459 DI 10.1103/PhysRevLett.80.456 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100008 ER PT J AU Shiell, RC Evans, M Stimson, S Hsu, CW Ng, CY Hepburn, JW AF Shiell, RC Evans, M Stimson, S Hsu, CW Ng, CY Hepburn, JW TI High resolution study of low lying correlation satellites in xenon SO PHYSICAL REVIEW LETTERS LA English DT Article ID PHOTOELECTRON-SPECTRUM; CROSS-SECTIONS; RARE-GASES; THRESHOLD; XE; DISTRIBUTIONS; SPECTROSCOPY AB The technique of pulsed field ionization-zero kinetic energy photoelectron spectroscopy, typically applied to the investigation of ionic states of atoms and molecules resulting from single electron excitation, has been used to probe the correlation satellite states of xenon between 23.6-24.7 eV. The resulting spectra show the formation of clearly resolved satellite states with intensities of a similar magnitude to that of the 5s5p(62)S(1/2) ionic state. This technique can be extended to other atomic and molecular species to obtain the positions and cross sections for the formation of such states. C1 Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Shiell, RC (reprint author), Univ Waterloo, Dept Chem, Waterloo, ON N2L 3G1, Canada. NR 21 TC 16 Z9 17 U1 0 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 19 PY 1998 VL 80 IS 3 BP 472 EP 475 DI 10.1103/PhysRevLett.80.472 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100012 ER PT J AU Mikaelian, KO AF Mikaelian, KO TI Analytic approach to nonlinear Rayleigh-Taylor and Richtmyer-Meshkov instabilities SO PHYSICAL REVIEW LETTERS LA English DT Article ID SURFACE AB We present analytic formulas for the nonlinear evolution of the bubble amplitude in Rayleigh-Taylor and Richtmyer-Meshkov instabilities in two and three dimensions. Direct numerical simulations of He/Xe shock tube experiments are also presented and the results are found to agree well with the analytic formulas which are based on an extension of Layzer's theory [Astrophys. J. 122, 1 1955)]. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mikaelian, KO (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 14 TC 58 Z9 58 U1 0 U2 18 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 19 PY 1998 VL 80 IS 3 BP 508 EP 511 DI 10.1103/PhysRevLett.80.508 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100021 ER PT J AU Mason, RJ Tabak, M AF Mason, RJ Tabak, M TI Magnetic field generation in high-intensity-laser-matter interactions SO PHYSICAL REVIEW LETTERS LA English DT Article ID PLASMA; SIMULATION AB A multifluid implicit plasma simulation code has been used to study the transport of hot electrons generated by an intense (greater than or equal to 3 x 10(18) W/cm(2)) short-pulse 1.06 mu m laser into plasma targets over a broad range of densities [(0.35-200)n(crit)], as arising in the Fast Ignitor approach to inertial confinement fusion. The most intense (16-250 MG) magnetic fields generated in this interaction are traced to the pondcromotive push on background electrons, and tardy electron shielding. These fields can focus the heated electrons toward the axis of the beam, while impeding the direct return flow of background electrons. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Mason, RJ (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NR 21 TC 97 Z9 106 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 19 PY 1998 VL 80 IS 3 BP 524 EP 527 DI 10.1103/PhysRevLett.80.524 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100025 ER PT J AU Hirshman, SP Spong, DA Whitson, JC Lynch, VE Batchelor, DB Carreras, BA Rome, JA AF Hirshman, SP Spong, DA Whitson, JC Lynch, VE Batchelor, DB Carreras, BA Rome, JA TI Transport optimization and MHD stability of a small aspect ratio toroidal hybrid stellarator SO PHYSICAL REVIEW LETTERS LA English DT Article ID FIELDS AB A class of small aspect ratio (A) stellarators is found that does nut rely on quasisymmetrization to achieve goad confinement. These systems depart from canonical stellarators by allowing a small net plasma current. An optimization procedure with bounce-averaged omnigeneity and other desirable physical properties as target criteria is described and applied to show the existence of a compact plasma device haring A less than or equal to 3, high beta (ratio of thermal energy to magnetic field energy), and low plasma current. The added design flexibility afforded by the plasma current leads to an attractive low-A hybrid device which is stable to magnetohydrodynamic ballooning modes for (beta) < 6%. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RP Hirshman, SP (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37830 USA. RI Spong, Donald/C-6887-2012; Lynch, Vickie/J-4647-2012 OI Spong, Donald/0000-0003-2370-1873; Lynch, Vickie/0000-0002-5836-7636 NR 18 TC 17 Z9 17 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 JAN 19 PY 1998 VL 80 IS 3 BP 528 EP 531 DI 10.1103/PhysRevLett.80.528 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100026 ER PT J AU Kwok, WK Paulius, LM Vinokur, VM Petrean, AM Ronningen, RM Crabtree, GW AF Kwok, WK Paulius, LM Vinokur, VM Petrean, AM Ronningen, RM Crabtree, GW TI Vortex pinning of anisotropically splayed defects YBa2Cu3O7-delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID HIGH-TEMPERATURE SUPERCONDUCTORS; SINGLE-CRYSTAL YBA2CU3O7; 0.8 GEV PROTONS; CU-O CRYSTALS; COLUMNAR DEFECTS; ELECTRON-IRRADIATION; BOSON LOCALIZATION; MELTING TRANSITION; ENHANCEMENT; DISORDER AB Pinning by splayed defects created by 3.9 GeV Au-197(29+) lolls is studied using transport measurements uf vortex motion perpendicular and parallel to the splay plane in untwinned crystals of YBa2Cu3O7-delta. We compare the transport properties of the crystals and demonstrate (i) a new 1/H dependence of the vortex liquid pinning energy, (ii) a crossing of the Irreversibility lines before and after irradiation, and (iii) a stronger temperature dependence of the critical current for vortex motion perpendicular to the splay plane than for motion parallel to the splay plane. C1 Argonne Natl Lab, Mat Sci & Sci & Technol Ctr Superconduct, Argonne, IL 60435 USA. RP Kwok, WK (reprint author), Argonne Natl Lab, Mat Sci & Sci & Technol Ctr Superconduct, Argonne, IL 60435 USA. NR 30 TC 33 Z9 34 U1 2 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 19 PY 1998 VL 80 IS 3 BP 600 EP 603 DI 10.1103/PhysRevLett.80.600 PG 4 WC Physics, Multidisciplinary SC Physics GA YT463 UT WOS:000071606100044 ER PT J AU Arnold, DW Korolik, M Wittig, C Reisler, H AF Arnold, DW Korolik, M Wittig, C Reisler, H TI The effect of translational energy on collision-induced dissociation of highly excited NO2 on MgO(100) SO CHEMICAL PHYSICS LETTERS LA English DT Article ID PRODUCT STATE DISTRIBUTIONS; DIRECT INELASTIC-SCATTERING; UNIMOLECULAR DECOMPOSITION; MOLECULAR COLLIDERS; TRANSITION-STATE; COOLED NO2 AB Collision-induced dissociation of highly excited NO2 (i.e., mixed B-2(2)/(2)A(1) molecular eigenstates just below D-0) impinging on MgO(100) surfaces has been studied as a function of NO2 internal excitation at an incident translational energy of 4400 cm(-1) by using state-selective NO detection. NO internal energy distributions as well as the average energy transferred per activating collision have been obtained. The results, in particular the NO [(II1/2)-I-2]/[(II3/2)-I-2] population ratios, indicate the presence of exit-channel interactions with the surface that are dependent on collision energy. (C) 1998 Elsevier Science B.V. C1 Univ So Calif, Dept Chem, Los Angeles, CA 90089 USA. RP Arnold, DW (reprint author), Sandia Natl Lab, Mail Stop 9671, Livermore, CA 94551 USA. NR 15 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 JAN 16 PY 1998 VL 282 IS 3-4 BP 313 EP 317 DI 10.1016/S0009-2614(97)01277-3 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA ZA368 UT WOS:000072356500016 ER PT J AU Li, J Fritz, JS AF Li, J Fritz, JS TI Novel polymeric resins for anion-exchange chromatography SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE anion exchangers; stationary phases, LC; inorganic anions; alkylphenols; alkylbenzenes ID SIMULTANEOUS SEPARATION; ION CHROMATOGRAPHY; STATIONARY-PHASE; COLUMN; ELUENTS; CATIONS AB A novel anion-exchange resin containing three amine groups was prepared by reaction of a chloromethylated polystyrene-divinylbenzene (PS-DVB) resin with diethylenetriamine. After being protonated by contact with an aqueous acid, this resin can be used for ion-chromatographic separation of anions. The charge on the resins can be varied from +1 to +3 by changing the pH at which the ion chromatographic separation was carried out. The selectivity of the new ion exchangers for various inorganic anions was quite different from conventional anion exchangers. The performance of this new anion exchanger was studied by changing the pH and the concentration of the eluent, and several different eluents were used with some common anions as testing analytes. Conductivity detection and UV-Vis detection were applied to detect the anions after separation. The new resin can also be used for HPLC separation of neutral organic compounds. Alkylphenols and alkylbenzenes were separated with this new polymeric resin, and excellent separations were obtained under simple conditions. (C) 1998 Elsevier Science B.V. C1 Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. RP Fritz, JS (reprint author), Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. NR 21 TC 20 Z9 24 U1 1 U2 10 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JAN 16 PY 1998 VL 793 IS 2 BP 231 EP 238 DI 10.1016/S0021-9673(97)00905-9 PG 8 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YT993 UT WOS:000071668800002 ER PT J AU Dindal, AB Ma, CY Skeen, JT Jenkins, RA AF Dindal, AB Ma, CY Skeen, JT Jenkins, RA TI Novel calibration technique for headspace analysis of semivolatile compounds SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE headspace analysis; calibration trap; tributyl phosphate; dibutyl butyl phosphonate ID SUPERCRITICAL-FLUID EXTRACTION; URANIUM; REMOVAL; THORIUM AB Vapor phase trap spiking methods have been developed and used for the analysis of volatile organic compounds. Because of their lower vapor pressures, this approach is not suitable for some semivolatile analytes, such as tributyl phosphate (TBP) and dibutyl butyl phosphonate (DBBP). A method was developed to independently quantify TBP and DBBP using a unique trap loading technique, and subsequent thermal desorption/gas chromatographic analysis. Modification of a gas chromatograph injection port allowed methanolic standards to be loaded onto sorbent traps quantitatively. The loaded calibration traps were then thermally desorbed and analyzed. Linearity, reproducibility, accuracy and method detection limits were established and will be reported for TBP and DBBP standards. (C) 1998 Elsevier Science B.V. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Lockheed Martin Energy Res Corp, Oak Ridge, TN 37831 USA. RP Dindal, AB (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Lockheed Martin Energy Res Corp, POB 2008,Bldg 4500S,MS-6120, Oak Ridge, TN 37831 USA. NR 11 TC 2 Z9 2 U1 1 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JAN 16 PY 1998 VL 793 IS 2 BP 397 EP 402 DI 10.1016/S0021-9673(97)00925-4 PG 6 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YT993 UT WOS:000071668800021 ER PT J AU Wlodawer, A Davies, D Petsko, G Rossmann, M Olson, A Sussman, JL AF Wlodawer, A Davies, D Petsko, G Rossmann, M Olson, A Sussman, JL TI Immediate release of crystallographic data: A proposal SO SCIENCE LA English DT Letter C1 NCI, Macromol Struct Lab, Frederick Canc Res & Dev Ctr, Frederick, MD 21702 USA. NIDDKD, Sect Mol Struct, NIH, Bethesda, MD 20892 USA. Brandeis Univ, Rosenstiel Basic Med Sci Res Ctr, Waltham, MA 02254 USA. Purdue Univ, Dept Biol Sci, W Lafayette, IN 47907 USA. Scripps Res Inst, Dept Mol Biol, La Jolla, CA 92037 USA. Brookhaven Natl Lab, Prot Data Bank, Upton, NY 11973 USA. Weizmann Inst Sci, Dept Biol Struct, IL-76100 Rehovot, Israel. RP Wlodawer, A (reprint author), NCI, Macromol Struct Lab, Frederick Canc Res & Dev Ctr, Frederick, MD 21702 USA. NR 1 TC 6 Z9 6 U1 0 U2 0 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 16 PY 1998 VL 279 IS 5349 BP 306 EP 307 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT158 UT WOS:000071570800008 PM 9454319 ER PT J AU Knill, E Laflamme, R Zurek, WH AF Knill, E Laflamme, R Zurek, WH TI Resilient quantum computation SO SCIENCE LA English DT Article ID ERROR-CORRECTING CODES AB Practical realization of quantum computers will require overcoming decoherence and operational errors, which lead to problems that are more severe than in classical computation. It is shown that arbitrarily accurate quantum computation is possible provided that the error per operation is below a threshold value. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Knill, E (reprint author), Los Alamos Natl Lab, CIC-3,Mail Stop B265, Los Alamos, NM 87545 USA. NR 36 TC 314 Z9 320 U1 5 U2 20 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 EI 1095-9203 J9 SCIENCE JI Science PD JAN 16 PY 1998 VL 279 IS 5349 BP 342 EP 345 DI 10.1126/science.279.5349.342 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT158 UT WOS:000071570800035 ER PT J AU Josse, F Lee, Y Martin, SJ Cernosek, RW AF Josse, F Lee, Y Martin, SJ Cernosek, RW TI Analysis of the radial dependence of mass sensitivity for modified-electrode quartz crystal resonators SO ANALYTICAL CHEMISTRY LA English DT Article ID THICKNESS-SHEAR; MICROBALANCE; LIQUID; PROFILE AB The radial dependence of mass sensitivity of the sensing surface is analytically calculated for two examples of "modified-electrode" quartz crystal resonators (QCR), The term "modified-electrode" QCR is used here with respect to the conventional QCR which has two identical circular and concentric electrodes, For these QCRs, the sensing surface is divided into a fully electroded, a partially electroded, and an unelectroded region, and the efficiency of each region is evaluated in terms of the electrode mass loading factor, Such QCRs are typically investigated for sensor applications in which the electrical properties of the liquid load or the coating deposited on the sensing surface (electroded and partially electroded regions) are being measured in addition to mass loading, While modified-electrode QCRs can be viewed as a simple capacitance sensor in those applications, the use of a piezoelectric crystal resonator in the narrow range of frequencies near resonance and antiresonance allows for a direct measurement of the capacitance through the antiresonant frequency, provided that the device damping (motional resistance) is not too high or that the resonance quality factor, Q, is high enough for a stable vibration under the load, It is shown that, for some values of the electrode mass loading factor, the off-electrode efficiency (partially electroded and unelectroded region efficiency) can still have a significant contribution to the overall surface area mass sensitivity, Knowledge of the efficiencies is needed to determine the loading area required for stable QCR sensor operation, This is because additional dissipation of energy into the load can occur, especially for cases where the sample load extends to the unelectroded surface, which has a nonnegligible particle displacement amplitude, It is also shown that, for some applications involving a liquid load and for some values of the electrode thickness, the shear particle displacement profile is such that compressional wave generation can contribute significantly to device damping, thus making the device unstable, Experimental measurements of the mass sensitivity profile on the surface are also performed for those QCRs and compared to theory. C1 Marquette Univ, Microsensor Res Lab, Milwaukee, WI 53201 USA. Marquette Univ, Dept Elect & Comp Engn, Milwaukee, WI 53201 USA. Sandia Natl Labs, Microsensors Res & Dev Dept, Albuquerque, NM 87185 USA. RP Josse, F (reprint author), Marquette Univ, Microsensor Res Lab, POB 1881, Milwaukee, WI 53201 USA. NR 26 TC 46 Z9 47 U1 2 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JAN 15 PY 1998 VL 70 IS 2 BP 237 EP 247 DI 10.1021/ac9706032 PG 11 WC Chemistry, Analytical SC Chemistry GA YR503 UT WOS:000071501800006 ER PT J AU Laintz, KE Hale, CD Stark, P Rouquette, CL Wilkinson, J AF Laintz, KE Hale, CD Stark, P Rouquette, CL Wilkinson, J TI A comparison of liquid and supercritical carbon dioxide as an extraction solvent for plating bath treatment SO ANALYTICAL CHEMISTRY LA English DT Article ID SOLID MATERIALS; FLUID EXTRACTION; LANTHANIDES; RECOVERY; METALS AB Because of increasing federal regulations, alternative metal recovery methods for spent electroplating baths are needed. Supercritical extraction of waste metals using CO2 is potential candidate for this process. However, because of the high-cost of supercritical fluid processing equipment, an extraction system modeled on the use of liquid CO2 rather than supercritical CO2 may be more economical. For this reason, the use of liquid CO2 contained beta-diketones as an extraction solvent for the removal of Ni2+ and Zn2+ from an electroplating solution was investigated and compared to results obtained with supercritical CO2. Acetylacetone (ACAC) and its fluorinated analogues were used as the ligands for the extraction of Ni2+ and Zn2+ from the electroplating bath. While the fluorinated ACAC showed a potential for a higher extraction efficiency, over 70% of both Ni2+ and Zn2+ was extracted using both liquid and supercritical CO2 using a 100-fold molar excess of ACAC. With isopropyl alcohol as a modifier, extraction efficiency was increased to over 80% for both metals using both phases of CO2 as the carrier fluid. C1 Univ Calif Los Alamos Natl Lab, Div Chem Sci & Technol, Los Alamos, NM 87545 USA. RP Laintz, KE (reprint author), Isotag Res, LLC, 600 6th St, Los Alamos, NM 87544 USA. NR 15 TC 26 Z9 27 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JAN 15 PY 1998 VL 70 IS 2 BP 400 EP 404 DI 10.1021/ac9702857 PG 5 WC Chemistry, Analytical SC Chemistry GA YR503 UT WOS:000071501800030 ER PT J AU Tolic, LP Bruce, JE Lei, QP Anderson, GA Smith, RD AF Tolic, LP Bruce, JE Lei, QP Anderson, GA Smith, RD TI In-trap cleanup of proteins from electrospray ionization using soft sustained off-resonance irradiation with Fourier transform ion cyclotron resonance mass spectrometry SO ANALYTICAL CHEMISTRY LA English DT Article ID OLIGONUCLEOTIDES; ACCUMULATION; ASSOCIATIONS; COMPLEXES; ENZYME AB Electrospray ionization Fourier transform ion cyclotron resonance (FI?CR) mass spectrometry is capable of producing high mass resolving power and improved mass accuracy for large proteins and noncovalent complexes when coupled with collisionally induced dissociation (CID) of noncovalent adducts and consequent minimization of ion charge density in the ICR trap during measurements. This work demonstrates the application of in-trap cleanup to several biologically relevant systems, including carbonic anhydrase, 4-oxalocrotonate tautomerase (4OT) analogue, and SecB, a chaperone from Escherichia coli. In-trap cleanup yields improved mass measurements for these systems and is expected to further enable measurements for even more complex systems where adduction levels have precluded study of intact complexes. C1 Pacific NW Natl Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Smith, RD (reprint author), Pacific NW Natl Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. EM rd_smith@pnl.gov RI Smith, Richard/J-3664-2012 OI Smith, Richard/0000-0002-2381-2349 FU NIGMS NIH HHS [GM 53558] NR 28 TC 20 Z9 20 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD JAN 15 PY 1998 VL 70 IS 2 BP 405 EP 408 DI 10.1021/ac970828c PG 4 WC Chemistry, Analytical SC Chemistry GA YR503 UT WOS:000071501800031 PM 9450366 ER PT J AU Vladusic, EA Hornby, AE Guerra-Vladusic, FK Lupu, R AF Vladusic, EA Hornby, AE Guerra-Vladusic, FK Lupu, R TI Expression of estrogen receptor beta messenger RNA variant in breast cancer SO CANCER RESEARCH LA English DT Article ID IDENTIFICATION; RESISTANCE; TAMOXIFEN; TUMORS; CELLS AB Estrogen receptor (ER) beta is expressed in a number of tissues, including the breast. We have recently shown that ER-beta mRNA is regulated by estradiol (E-2) and that antiestrogens antagonize E-2 induction of ER-beta mRNA. Here, we identify by reverse transcription-PCR and by the RNase protection assay a mRNA coding for a variant of ER-beta that is coexpressed with wild-type ER-beta in the ER-alpha-negative, estrogen-independent breast cancer cell line MDA-MB-231 and in malignant breast tumor specimens. In contrast, this variant was not seen in the tested normal breast tissue. Sequence analysis of the ER-beta variant PCR product revealed the absence of 139 bp within the hormone-binding domain. This ER-beta deletion corresponds precisely to the entire exon 5 of ER-alpha. The ER-beta variant protein is predicted to lack part of the hormone-binding domain and may bind E-2 with lower affinity than the wild-type ER-beta protein. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Lupu, R (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM rlupu@lbl.gov NR 30 TC 143 Z9 147 U1 1 U2 3 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD JAN 15 PY 1998 VL 58 IS 2 BP 210 EP 214 PG 5 WC Oncology SC Oncology GA YR421 UT WOS:000071493600006 PM 9443393 ER PT J AU Bao, SP Thrall, BD Gies, RA Miller, DL AF Bao, SP Thrall, BD Gies, RA Miller, DL TI In vivo transfection of melanoma cells by lithotripter shock waves SO CANCER RESEARCH LA English DT Article ID GENE-THERAPY; EXPRESSION; TUMORS; SKIN AB The potential for gene transfection during shock wave tumor therapy was evaluated by searching for shock wave-induced DNA transfer in mouse tumor cells. B16 mouse melanoma cells were cultured by standard methods and implanted s.c. in female C57BL/6 mice 10-14 days before treatment. A luciferase reporter vector was used as the DNA plasmid for intratumoral injection at 0.2 mg/ml tumor, Air at 10% of tumor volume was injected after the DNA in some tumors to enhance acoustic cavitation activity. The shock wave generation system was similar to a Dornier HM-3 lithotripter with pressure amplitudes of 24.4 MPa peak positive and 5.2 MPa peak negative. Luciferase production in isolated tumor cells was measured with a luminometer 1 day after treatment to assess gene transfer and expression. Exposure to 800 shock waves, followed by immediate isolation and culture of tumor cells for 1 day, yielded 1.1 (0.43 SE) pg/10(6) cells for plasmid injection only and 7.5 (2.5 SE) pg/10(6) cells for plasmid plus air injection, Significantly increased luciferase production, relative to shams, occurred for 200-, 400-, 800-, and 1200-shock wave treatments with plasmid and air injection. Exposure with the isolation of tumor cells delayed for a day to allow gene expression within the growing tumors gave increased luciferase production for 100- and 400-shock wave exposures without and with air injection. Gene transfer therefore can be induced during lithotripter shock wave treatment in vivo, particularly with enhanced acoustic cavitation, which supports the concept that gene and shock wave therapy might be advantageously merged. C1 Pacific NW Lab, Richland, WA 99352 USA. Washington State Univ, US Transuranium & Uranium Registries, Richland, WA 99352 USA. RP Miller, DL (reprint author), Pacific NW Lab, POB 999, Richland, WA 99352 USA. RI WSU, USTUR/I-1056-2013 FU NCI NIH HHS [CA42947] NR 20 TC 83 Z9 88 U1 0 U2 5 PU AMER ASSOC CANCER RESEARCH PI BIRMINGHAM PA PO BOX 11806, BIRMINGHAM, AL 35202 USA SN 0008-5472 J9 CANCER RES JI Cancer Res. PD JAN 15 PY 1998 VL 58 IS 2 BP 219 EP 221 PG 3 WC Oncology SC Oncology GA YR421 UT WOS:000071493600008 PM 9443395 ER PT J AU Tarasov, VF Yashiro, H Maeda, K Azumi, T Shkrob, IA AF Tarasov, VF Yashiro, H Maeda, K Azumi, T Shkrob, IA TI Time-resolved ESR in a spin-correlated radical pair with large hyperfine coupling constant at P-31. Micellar size effects and the role of flip-flop transitions SO CHEMICAL PHYSICS LA English DT Article ID INDUCED MAGNETIC-POLARIZATION; DYNAMIC ELECTRON POLARIZATION; LASER FLASH-PHOTOLYSIS; EXCHANGE INTERACTION; (2,4,6-TRIMETHYLBENZOYL)DIPHENYLPHOSPHINE OXIDE; NONADIABATIC TRANSITIONS; ACYLPHOSPHINE OXIDES; RESONANCE-SPECTRA; RECOMBINATION; CIDEP AB Time-resolved ESR spectra from spin-correlated pairs of diphenyl phosphonyl and 2,4,6-trimethylbenzoyl radicals were observed in 308 nm laser photolysis of (2,4,6-trimethylbenzoyl)-diphenylphosphine oxide in sodium alkylsulfate micelles (C-8-C-12). These ESR spectra exhibit unusual polarization patterns in which the M = +1/2 resonance line of diphenyl phosphonyl is split into two inversely polarized components while the M = -1/2 line is in the net absorption. This pattern is shown to result from flip-flop electron-nuclear spin transitions in the diphenyl phosphonyl radical (A[P-31] = 38.5 mT). The corresponding mechanism is an extension of the familiar ST- radical pair mechanism tospin-correlated pairs. Our analysis indicates that in micelles, flip-flop transitions, in concert with the exchange relaxation, equilibrate all three spin states in the F-z = -1/2 manifold of the pair (where F-z is the projection of the total spin of the pair). In the studied system, this equilibration occurs in similar to 100 ns. The equilibration of the F-z = +1/2 states, due to less efficient non-adiabatic ST+ transitions, is much slower and takes microseconds. (C) 1998 Elsevier Science B.V. C1 Tohoku Univ, Dept Chem, Sendai, Miyagi 98077, Japan. Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Tarasov, VF (reprint author), Univ N Carolina, Dept Chem, Venable & Kenan Labs, CB 3290, Chapel Hill, NC 27599 USA. RI Maeda, Kiminori/A-3500-2012 NR 51 TC 18 Z9 18 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-0104 J9 CHEM PHYS JI Chem. Phys. PD JAN 15 PY 1998 VL 226 IS 3 BP 253 EP 269 DI 10.1016/S0301-0104(97)00330-3 PG 17 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YY574 UT WOS:000072161800002 ER PT J AU Gorby, YA Caccavo, F Bolton, H AF Gorby, YA Caccavo, F Bolton, H TI Microbial reduction of cobalt(III)EDTA(-) in the presence and absence of manganese(IV) oxide SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID DISSIMILATORY REDUCTION; WASTE-DISPOSAL; IRON; ADSORPTION; OXIDATION; CO(II)EDTA; MIGRATION; COMPLEXES; TRANSPORT; SEDIMENTS AB Codisposal of Co-60(2+) and EDTA has promoted the transport of radioactive Co-60 in the environment as (60)CoEDTA complexes. Chemical oxidation of Co(II)EDTA(2-) to highly stable and mobile Co(III)EDTA(-) by manganese(VI) oxide minerals can occur under aerobic and anaerobic conditions. Reduction of Co(lll) to Co(ll) decreases the stability of the radionuclide-chelate complex and can limit the transport of the Co-60 in subsurface environments. This study investigated the microbial reduction of Co(III)EDTA(-) in the presence and absence of reactive manganese(IV) oxides. The metal-reducing bacterium Shewanella alga strain BrY enzymatically reduced Co(III)EDTA(-) to Co(II)EDTA(2-) with a 1:1 stoichiometry. Reduction of Co(III)EDTA(-) was not affected by radioactive (60)Co(III)EDTA(-) at concentrations exceeding those recorded in contaminated environments. Bacterial reduction of Co(III)EDTA(-) could he coupled to the chemical oxidation of Co(II)EDTA(2-) by the manganese(IV) oxide mineral pyrolusite, resulting in biotic-abiotic cycling between Co(II)EDTA(2-) and Co(III)EDTA(-). Co(III)EDTA(-) significantly increased the rate and extent of manganese(IV) oxide reduction in the presence of metal reducing bacteria, and the Co(II)EDTA(2-) complex did not dissociate in these anoxic studies. Direct reduction of Co(III)EDTA(-) by microorganisms and geochemical oxidation of Co(II)EDTA(2-) by manganese(IV) oxides are important components of a complex set of coupled microbial and geochemical reactions that may influence the fate and transport of (60)Co(III)EDTA(2-) in the environment. C1 Pacific NW Natl Lab, Environm Microbiol Grp, Richland, WA 99352 USA. Univ New Hampshire, Dept Microbiol, Durham, NH 03824 USA. RP Gorby, YA (reprint author), Pacific NW Natl Lab, Environm Microbiol Grp, Mailstop P7-54,POB 999, Richland, WA 99352 USA. RI Bolton, Harvey/E-5583-2011 NR 24 TC 43 Z9 45 U1 5 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JAN 15 PY 1998 VL 32 IS 2 BP 244 EP 250 DI 10.1021/es970516r PG 7 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA YR900 UT WOS:000071542800008 ER PT J AU Blair, DS Bando, J AF Blair, DS Bando, J TI Quantitative monitoring of volatile organic compounds in water using an evanescent fiber optic chemical sensor SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHLORINATED HYDROCARBONS; INFRARED FIBERS; WAVE; ABSORPTION AB This work evaluates the usefulness of two linear chemometric algorithms, principle component regression and partial least-squares analysis, for modeling the responses of an evanescent fiber optic chemical sensor to aqueous mixtures of organic analytes with individual concentrations ranging from 50 to 200 ppm. Two data sets were examined. One contained trichloroethylene, 1,1,2 trichloroethane, toluene, and chloroform. The second set contained these four analytes as well as tetrachloroethene. Both chemometric algorithms performed comparably on a given data set with cross-validated root mean squared errors of prediction (RMSEP) for trichloroethylene, 1,1,2 trichloroethane, toluene, and chloroform of approximately 6, 9, 6, and 16 ppm from the first set and 7, 11, 13, and 31 ppm from the second set with tetrachloroethene RMSEP of 31 ppm. The decrease in the quantitative performance of the algorithm for modeling toluene and chloroform upon addition of tetrachloroethene to the sample solutions is due to increased intensity of cladding absorption features in the spectral response matrix. These features overlap with the analyte absorption features of toluene and chloroform and reveal one of the limitations with this type of sensing format. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Blair, DS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 20 TC 15 Z9 15 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JAN 15 PY 1998 VL 32 IS 2 BP 294 EP 298 DI 10.1021/es9702428 PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA YR900 UT WOS:000071542800016 ER PT J AU Mohrenweiser, HW Tsujimoto, S Gordon, L Olsen, AS AF Mohrenweiser, HW Tsujimoto, S Gordon, L Olsen, AS TI Regions of sex-specific hypo- and hyper-recombination identified through integration of 180 genetic markers into the metric physical map of human chromosome 19 SO GENOMICS LA English DT Article ID SITU HYBRIDIZATION MAP; HUMAN GENOME; REPEAT-POLYMORPHISM; LINKAGE MAPS; MICROSATELLITE; INTERFERENCE; TELOMERE; HUMAN-CHROMOSOME-19; LOCATION; RATES AB The order of and physical distance between 180 polymorphic markers, many from the Genethon and CHLC genetic maps, have been determined through inclusion of probe-positive cosmids in the metric physical map of human chromosome 19. The markers incorporated into the physical map include 38 genetic markers with heterozygosities of >0.8 and similar to 120 markers with heterozygosities of >0.60. The average distance between markers in this integrated map is similar to 320 kb. Clustering of markers is noted in several regions of the chromosome; only II intervals exist where the distance between markers is greater than 1 Mb, with the largest gap being 1.6 Mb. The ratio of sex-average genetic distance from the Genethon and CHLC genetic linkage maps to physical distance in the metric map is approximately 1.7 cM/Mb for the entire chromosome but ranges from 4 cM/Mb across the telomeric bands to 1 cM/Mb for the centromeric cytogenetic bands. The recombination distance in males is approximately twice that of females in the most telomeric bands but is only 10-25% of the activity observed in females in the more centromeric bands. Seven regions along the chromosome are noted where the recombination distance between markers in one sex is greater than 10 times the recombination distance in the other sex. The integration of genetic markers into the high-resolution physical map of human chromosome 19 provides a framework for isolation of disease genes and resources for studies of genome organization, such as regions of interesting recombinational activity. (C) 1998 Academic Press. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Biol & Biotechnol Res Program, Livermore, CA 94550 USA. RP Mohrenweiser, HW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Biol & Biotechnol Res Program, L-452, Livermore, CA 94550 USA. EM harvey_mohrenweiser@B361.llnl.gov NR 38 TC 37 Z9 39 U1 0 U2 1 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA SN 0888-7543 J9 GENOMICS JI Genomics PD JAN 15 PY 1998 VL 47 IS 2 BP 153 EP 162 DI 10.1006/geno.1997.5097 PG 10 WC Biotechnology & Applied Microbiology; Genetics & Heredity SC Biotechnology & Applied Microbiology; Genetics & Heredity GA YW034 UT WOS:000071889000001 PM 9479487 ER PT J AU Ohba, T Raymond, S Shapiro, SM Otsuka, K AF Ohba, T Raymond, S Shapiro, SM Otsuka, K TI Phonon softening and time dependence of elastic peak appearing prior to the martensitic transformation in Au-47.5 at%Cd SO JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS LA English DT Article DE martensitic transformation; Au52.5Cd47.5; phonon softening; precursor phenomenon; time dependence; neutron inelastic scattering ID ALLOY; AU-49.5 AB There are two distinct martensites called gamma'(2) and zeta'(2) phases near the equi-atomic composition in AuCd alloy system. The phonon dispersion relation of the [zeta zeta 0]TA(2) branch was measured by inelastic neutron scattering in a AU(52.5)Cd(47.5) alloy which produces gamma'(2) martensite. The difficulty of strong neutron absorption was overcome by the use of an isotope Cd-114. The softening was observed at the Brillouin zone boundary and at zeta = 0.35. An elastic peak was observed at zeta = 0.35, but not at the zone boundary. The peculiar time dependent behavior was observed in the elastic peak. C1 Teikyo Univ, Dept Mat Sci & Engn, Utsunomiya, Tochigi 320, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. Univ Tsukuba, Inst Mat Sci, Ibaraki, Osaka 305, Japan. RP Ohba, T (reprint author), Teikyo Univ, Dept Mat Sci & Engn, Utsunomiya, Tochigi 320, Japan. NR 12 TC 17 Z9 17 U1 1 U2 1 PU JAPAN J APPLIED PHYSICS PI MINATO-KU TOKYO PA DAINI TOYOKAIJI BLDG 24-8 SHINBASHI 4-CHOME, MINATO-KU TOKYO, 105, JAPAN J9 JPN J APPL PHYS 2 JI Jpn. J. Appl. Phys. Part 2 - Lett. PD JAN 15 PY 1998 VL 37 IS 1AB BP L64 EP L66 DI 10.1143/JJAP.37.L64 PG 3 WC Physics, Applied SC Physics GA YW769 UT WOS:000071972200022 ER PT J AU Maya, L Thompson, JR Song, KJ Warmack, RJ AF Maya, L Thompson, JR Song, KJ Warmack, RJ TI Thermal conversion of an iron nitride silicon nitride precursor into a ferromagnetic nanocomposite SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID MAGNETIC-PROPERTIES; FILMS; COERCIVITY; SOLIDS AB Iron nitride films, FeN, in a pure form and in the form of a nanocomposite in silicon nitride were prepared by reactive sputtering using iron or iron disilicide, respectively, as targets in a nitrogen plasma. Iron nitride decomposes into the elements by heating in vacuum to 800 degrees C. Intermediate phases such as Fe2N or Fe4N form at lower temperatures. The nanocomposites contain the iron phases as particles with an average size of similar to 5 nm dispersed in the amorphous silicon nitride matrix. The magnetic properties of the nanocomposites were established. The precursor FeN-Si3N4 film is paramagnetic, while the Fe-Si3N4, obtained by heating in vacuum, is ferromagnetic and shows typical superparamagnetic behavior. These films are of interest as recording media with superior chemical and mechanical stability and may be encoded by localized heating. [S0021-8979(98)02902-8]. C1 Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Hlth Sci Res, Oak Ridge, TN 37831 USA. RP Maya, L (reprint author), Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. NR 19 TC 4 Z9 4 U1 1 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1998 VL 83 IS 2 BP 905 EP 910 DI 10.1063/1.366776 PG 6 WC Physics, Applied SC Physics GA YR575 UT WOS:000071509000043 ER PT J AU Gopalan, V Mitchell, TE AF Gopalan, V Mitchell, TE TI Wall velocities, switching times, and the stabilization mechanism of 180 degrees domains in congruent LiTaO3 crystals SO JOURNAL OF APPLIED PHYSICS LA English DT Article ID INTERNAL BIAS; SINGLE-CRYSTALS; ELECTRIC-FIELDS; THIN-FILMS; LINBO3; MICRODOMAINS; CERAMICS; DEVICES; BOUNDARIES; INVERSION AB A systematic study of the kinetics of 180 degrees domains as a function of external electric field is presented for Z-cut LiTaO3 single crystal wafers at room temperature using transient current measurements combined with nondestructive and real-time imaging of 180 degrees domains by light microscopy. The switching time, wall velocity, and nucleation rate follow an exponential behavior with the applied field. A model is proposed which shows that the nucleation and sideways growth of domains play approximately equal parts in determining the switching time. A domain stabilization process occurs on the time scale of a few seconds even at electric fields where the switching time is milliseconds or less. We show that this stabilization process has a strong correlation to the internal fields in the crystal. (C) 1998 American Institute of Physics. [S0021-8979(98)04602-7]. C1 Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. RP Gopalan, V (reprint author), Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, MS K765, Los Alamos, NM 87545 USA. NR 56 TC 105 Z9 107 U1 0 U2 12 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1998 VL 83 IS 2 BP 941 EP 954 DI 10.1063/1.366782 PG 14 WC Physics, Applied SC Physics GA YR575 UT WOS:000071509000049 ER PT J AU Seager, CH Missert, NA Tallant, DR Warren, WL AF Seager, CH Missert, NA Tallant, DR Warren, WL TI Scanning cathodoluminescence as a probe of surface recombination in phosphors excited at low electron energies SO JOURNAL OF APPLIED PHYSICS LA English DT Article AB Scanning cathodoluminescence (SCL) is a technique that has been widely used to categorize local minority carrier lifetime nonuniformities in bulk and thin him semiconductors. In the case of phosphor powders it has been less popular, partly because the collection and scattering of light generated in an array of particles complicates the extraction of quantitative information about light generation efficiency. Here we demonstrate that by coupling SCL with modern digital imaging manipulation techniques, we can extract quantitative information about the beam energy dependence of phosphor cathodoluminescence with high spatial resolution. A number of common phosphors are examined and a wide range of behavior is observed. We find that materials like ZnS:Ag and SrGa2S4:Eu display uniformly high nonradiative surface energy losses, while other materials like ZnO:Zn have surface losses which are spatially very nonuniform. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Seager, CH (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 12 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-8979 J9 J APPL PHYS JI J. Appl. Phys. PD JAN 15 PY 1998 VL 83 IS 2 BP 1153 EP 1155 DI 10.1063/1.366809 PG 3 WC Physics, Applied SC Physics GA YR575 UT WOS:000071509000077 ER PT J AU Hayashi, H Watanabe, N Udagawa, Y Kao, CC AF Hayashi, H Watanabe, N Udagawa, Y Kao, CC TI Optical spectra of liquid water in vacuum uv region by means of inelastic x-ray scattering spectroscopy SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID LOW-ENERGY ELECTRONS; OSCILLATOR-STRENGTHS; ABSORPTION; PHOTOABSORPTION; DEPOSITION; PHOTOIONIZATION; RADIATION; VAPOR; RANGE; H2O AB Inelastic x-ray scattering (IXS) spectroscopy using hard x-rays is in principle equivalent to optical spectroscopy as long as momentum transfer can be approximated to be zero. Hence IXS spectra of liquid water which corresponds to vacuum uv absorption were measured at small energy transfers with energy resolution of 0.5 eV. The loss function was derived from the spectra and its convergence for the momentum transfer smaller than 0.28 a.u. was confirmed. The reflectance spectrum and the optical oscillator strength have been calculated from the loss function. It is shown that the optical oscillator strength of liquid water differs considerably from that of gaseous water. (C) 1998 American Institute of Physics. [S0021-9606(98)52603-7]. C1 Tohoku Univ, Sci Measurements Res Inst, Aoba Ku, Sendai, Miyagi 98077, Japan. Brookhaven Natl Lab, Upton, NY 11973 USA. RP Hayashi, H (reprint author), Tohoku Univ, Sci Measurements Res Inst, Aoba Ku, 2-1-1 Katahira, Sendai, Miyagi 98077, Japan. OI Hayashi, Hisashi/0000-0002-8504-4066 NR 27 TC 59 Z9 59 U1 1 U2 6 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 JAN 15 PY 1998 VL 108 IS 3 BP 823 EP 825 DI 10.1063/1.475446 PG 3 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR359 UT WOS:000071487500001 ER PT J AU De Paul, SM Tomaselli, M Pines, A Ernst, M Meier, BH AF De Paul, SM Tomaselli, M Pines, A Ernst, M Meier, BH TI Reversal of radio-frequency-driven spin diffusion by reorientation of the sample spinning axis SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID NUCLEAR-MAGNETIC-RESONANCE; SOLID-STATE NMR; POLARIZATION-TRANSFER; ROTATIONAL RESONANCE; QUADRUPOLAR NUCLEI; ECHOES AB The dipolar Hamiltonian in a rapidly rotating sample is scaled by the second Legendre polynomial of the cosine of the angle between the rotation axis and the static magnetic field. It is, therefore, possible to refocus the spatial polarization-transfer process, often termed spin diffusion, in extended spin systems by reorienting the rotor axis such that the dipolar interaction Hamiltonian changes sign. We present experimental results which demonstrate that a rapid mechanical sample reorientation leads to a time reversal of the "radio-frequency-driven" spin diffusion among C-13 spins. (C) 1998 American Institute of Physics. [S0021-9606(98)03503-X]. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Nijmegen, Phys Chem Lab, NL-6525 ED Nijmegen, Netherlands. RP De Paul, SM (reprint author), Max Planck Inst Polymerforsch, Postfach 3148, D-55021 Mainz, Germany. RI Ernst, Matthias/A-6732-2010; Meier, Beat/K-4066-2016 OI Ernst, Matthias/0000-0002-9538-6086; Meier, Beat/0000-0002-9107-4464 NR 39 TC 9 Z9 9 U1 1 U2 3 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1998 VL 108 IS 3 BP 826 EP 829 DI 10.1063/1.475494 PG 4 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR359 UT WOS:000071487500002 ER PT J AU Gray, SK Balint-Kurti, GG AF Gray, SK Balint-Kurti, GG TI Quantum dynamics with real wave packets, including application to three-dimensional (J=0)D+H-2 -> HD+H reactive scattering SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID DISCRETE VARIABLE REPRESENTATION; DEPENDENT SCHRODINGER-EQUATION; POTENTIAL-ENERGY SURFACE; MATRIX KOHN METHOD; MOLECULAR PHOTOFRAGMENTATION; VIBRATIONAL PREDISSOCIATION; 3-DIMENSIONAL WAVEPACKET; STATE DISTRIBUTIONS; CROSS-SECTIONS; 3 DIMENSIONS AB We show how to extract S matrix elements for reactive scattering from just the real part of an evolving wave packet. A three-term recursion scheme allows the real part of a wave packet to be propagated without reference to its imaginary part, so S matrix elements can be calculated efficiently. Our approach can be applied not only to the usual time-dependent Schrodinger equation, but to a modified form with the Hamiltonian operator (H) over cap replaced by f((H) over cap), where f is chosen for convenience. One particular choice for f, a cos(-1) mapping, yields the Chebyshev iteration that has proved to be useful in several other recent studies. We show how reactive scattering can be studied by following time-dependent wave packets generated by this mapping. These ideas are illustrated through calculation of collinear H+H-2-->H-2+H and three-dimensional (J=0)D+H-2-->HD+D reactive scattering probabilities on the Liu-Siegbahn-Truhlar-Horowitz (LSTH) potential energy surface. (C) 1998 American Institute of Physics. [S0021-9606(98)02803-7]. C1 Argonne Natl Lab, Div Chem, Theoret Chem Grp, Argonne, IL 60439 USA. Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England. RP Gray, SK (reprint author), Argonne Natl Lab, Div Chem, Theoret Chem Grp, Argonne, IL 60439 USA. NR 64 TC 338 Z9 338 U1 3 U2 24 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1998 VL 108 IS 3 BP 950 EP 962 DI 10.1063/1.475495 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR359 UT WOS:000071487500016 ER PT J AU Nilson, RH Griffiths, SK AF Nilson, RH Griffiths, SK TI A locally analytic density functional theory describing adsorption and condensation in microporous materials SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID PORE-SIZE DISTRIBUTION; CARBON; NITROGEN; FLUIDS AB The fluid density distribution within microscopic pores is determined by solving integral equations relating the local chemical potential to the van der Waals attractions and hard sphere repulsions of surrounding material. To avoid resolving the density distribution on submolecular scales, the governing equations are averaged over zones of molecular size using analytic functions to represent local density variations within each zone, These local density profiles range from singularities to uniform distributions depending on the local variation of the potential field. Sample calculations indicate that this integral approach yields results in very good agreement with those based on traditional density functional theory, while reducing computing times by three or four orders of magnitude for one-dimensional geometries. (C) 1998 American Institute of Physics. [S0021-9606(98)51303-7]. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Nilson, RH (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 19 TC 4 Z9 4 U1 0 U2 0 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1998 VL 108 IS 3 BP 1162 EP 1174 DI 10.1063/1.475479 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR359 UT WOS:000071487500041 ER PT J AU Monks, PS Stief, LJ Krauss, M Kuo, SD Zhang, Z Klemm, RB AF Monks, PS Stief, LJ Krauss, M Kuo, SD Zhang, Z Klemm, RB TI Comment on "A study of Hel photoelectron spectroscopy on the electronic structure of the nitrate free radical NO3" SO JOURNAL OF CHEMICAL PHYSICS LA English DT Letter C1 NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. Ctr Adv Res Biotechnol, Rockville, MD 20850 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. RP Stief, LJ (reprint author), NASA, Goddard Space Flight Ctr, Extraterr Phys Lab, Greenbelt, MD 20771 USA. RI Monks, Paul/H-6468-2016 OI Monks, Paul/0000-0001-9984-4390 NR 2 TC 3 Z9 3 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 15 PY 1998 VL 108 IS 3 BP 1292 EP 1292 DI 10.1063/1.475492 PG 1 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YR359 UT WOS:000071487500055 ER PT J AU Al-Kahtani, A Williams, DL Nibler, JW Sharpe, SW AF Al-Kahtani, A Williams, DL Nibler, JW Sharpe, SW TI High-resolution infrared studies of Al(BH4)(3) and Al(BD4)(3) SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID TUNNELING SPLITTINGS; SPECTRA AB High-resolution (0.01 cm(-1)) FTIR spectra of AI(BH4)(3) and AI(BD4)(3) recorded for low-pressure samples at room temperature are presented that show only broad vibrational bands, with no trace of resolved rotational structure. The BH bridge stretching and the BH2 deformation regions were also examined at 0.001 cm(-1) resolution by tunable infrared diode laser spectroscopy for samples cooled to similar to 10 K in a multipass, slit expansion. These too show near continua, with much more congestion than predicted by nonrigid rotor simulations based on boron isotopic shifts, Coriolis constants, and centrifugal distortion parameters estimated from ab initio calculations. The latter indicate that a particularly low barrier, corresponding to the prismatic D-3h structure, separates two equivalent, lower energy D-3 forms in which the BH4 units are rotated 23 degrees about the Al-B axes. The potential energy surface for the relevant conrotary torsional coordinate is examined at the CCSD/6-311G**//MP2/6-311G** level, yielding a barrier height of 490 cm(-1) and v = 0 and 1 level splittings of 0.052 and 2.7 cm(-1), respectively. The extreme spectral congestion observed is believed to arise primarily from splittings of the ground state and the upper vibrational levels of modes that couple to this conrotary torsional motion and to other tumbling modes of the BH4 units. C1 Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. Pacific NW Lab, William A Wiley Environm Mol Sci Lab, Richland, WA 99352 USA. RP Nibler, JW (reprint author), Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA. EM niblerj@chem.orst.edu NR 29 TC 12 Z9 12 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 15 PY 1998 VL 102 IS 3 BP 537 EP 544 DI 10.1021/jp972684b PG 8 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV229 UT WOS:000071802300007 ER PT J AU Knickelbein, MB Koretsky, GM AF Knickelbein, MB Koretsky, GM TI Infrared studies of the interaction of methanol with Cu-n, Ag-n, and Au-n SO JOURNAL OF PHYSICAL CHEMISTRY A LA English DT Article ID ULTRAVIOLET PHOTOELECTRON-SPECTRA; ELECTRONIC SHELL STRUCTURE; COINAGE METAL-CLUSTERS; SMALL COPPER CLUSTERS; IONIZATION-POTENTIALS; SILVER CLUSTERS; MASS DISTRIBUTIONS; METHYL FORMATE; JELLIUM MODEL; SPECTROSCOPY AB Methanol (Me) adsorbs intact on copper, silver, and gold clusters at 70 K to form thp complexes CunMem, AgnMem, and AunMem, respectively. The infrared photodissociation spectra of the deuterium-substituted complexes M-n(CD3OH)(m) and M-n(CD3OD)(m) (M-n = Cu3-11, Ag3-22, and Au3-13) have been recorded in the 9-11 mu m region. The methanol C-O stretching band frequency is invariant with cluster size and depends only slightly on the metal of which the underlying cluster is composed, indicating that local interactions are responsible for the shift from the gas-phase value and that these interactions are similar for methanol adsorbed on clusters of all three metals. Progressive blue shifts of the depletion bands of AgnMem and AunMem with increasing m indicate a strong interaction among methanol ligands in these species. C1 Argonne Natl Lab, Div Chem, Argonne, IL 60439 USA. RP Knickelbein, MB (reprint author), Argonne Natl Lab, Div Chem, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 72 TC 51 Z9 51 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5639 J9 J PHYS CHEM A JI J. Phys. Chem. A PD JAN 15 PY 1998 VL 102 IS 3 BP 580 EP 586 DI 10.1021/jp973381k PG 7 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YV229 UT WOS:000071802300012 ER PT J AU Xu, L Lio, A Hu, J Ogletree, DF Salmeron, M AF Xu, L Lio, A Hu, J Ogletree, DF Salmeron, M TI Wetting and capillary phenomena of water on mica SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SCANNING-TUNNELING-MICROSCOPY; SURFACE-ENERGY; THIN-FILMS; ADSORPTION; SCALE; CONDUCTIVITY; FORCES AB The structure of water films on mica was locally modified by contact with the tip of an atomic force microscope (AFM) in a humid environment. The subsequent evolution of the film was studied by noncontact scanning polarization force microscopy. At high relative humidity (>20%), capillary condensation caused water to form droplets and two-dimensional islands around the contact point. The droplets evaporated in a short period of time, but the islands remained for much longer periods (hours). At low relative humidity (>20%), the tip contact produced a circular depression in the local polarizability. None of these structures could be observed in contact AFM images which revealed only the usual atomically flat mica surface. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. Chinese Acad Sci, Shanghai Inst Nucl Res, Shanghai 201800, Peoples R China. RP Salmeron, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Sci Mat, Berkeley, CA 94720 USA. EM salmeron@stm.lbl.gov RI Ogletree, D Frank/D-9833-2016 OI Ogletree, D Frank/0000-0002-8159-0182 NR 35 TC 208 Z9 210 U1 6 U2 64 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 15 PY 1998 VL 102 IS 3 BP 540 EP 548 DI 10.1021/jp972289l PG 9 WC Chemistry, Physical SC Chemistry GA YV233 UT WOS:000071802700009 ER PT J AU Dang, LX AF Dang, LX TI Importance of polarization effects in modeling the hydrogen bond in water using classical molecular dynamics techniques SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID SUPERCRITICAL WATER; LIQUID WATER; SIMULATION AB The importance of polarization effects in the hydrogen-bonding structures of water is evaluated using classical molecular dynamics techniques with a polarizable potential model [Dang, L. X.; Chang, T.-M. J. Chem. Phys. 1997, 106, 8149]. The computed water monomer dipole moment in water clusters is significantly enhanced because of induction effects created by other water molecules. In particular, the magnitude of polarization effects reported recently by high-level ab initio calculations [Gregory, J. K.; Clary, D. C.; Liu, K.: Brown, M. G.; Saykally, R. J. Science 1997, 275, 814] is well-reproduced in our simulations. The structure of liquid water at ambient and supercritical conditions is investigated. The evolution of the hydrogen-bonding peak in g(OH) is in good agreement with recent data obtained by neutron diffraction with isotopic substitution experiments (NDIS) [Postorino, P.; Tromp, RH.; Ricci, M. A.; Soper, A. K.; Neilson, G. W. Nature 1993, 366, 668]. This behavior can be attributed to the variability of water dipole moments in different environments, At conditions near critical temperature, in contrast with the interpretation of the NDIS data, the data from our simulations indicated that a considerable degree of hydrogen bonding remains at this state. This result is in good agreement with very recent proton NMR chemical shift measurements. C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Dang, LX (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 22 TC 72 Z9 72 U1 0 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 15 PY 1998 VL 102 IS 3 BP 620 EP 624 DI 10.1021/jp9731258 PG 5 WC Chemistry, Physical SC Chemistry GA YV233 UT WOS:000071802700020 ER PT J AU Bu, HS Cao, J Zhang, ZS Zhang, Z Festag, R Joy, DC Kwon, YK Wunderlich, B AF Bu, HS Cao, J Zhang, ZS Zhang, Z Festag, R Joy, DC Kwon, YK Wunderlich, B TI Structure of single-molecule single crystals of isotactic polystyrene and their radiation resistance SO JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS LA English DT Article DE polystyrene; single-molecule single crystal; radiation resistance; lattice image ID RESOLUTION ELECTRON-MICROSCOPY; POLYMERS AB The structure of single-molecule single crystals of isotactic polystyrene (i-PS) was investigated by electron diffraction (ED). The nanoscale single-molecule single crystals were found to be more resistant to electron irradiation when compared to the larger crystals of many molecules, as indicated by both observation of ED and high-resolution electron microscopy with increasing radiation dose. It is proposed that since the single-molecule single crystals are very small, the secondary electrons escape more frequently from the crystal so that the radiation damage is reduced. Lattice imaging was achieved at room temperature in the case of single-molecule single crystals because of their stability to electron irradiation. (C) 1998 John Wiley & Sons, Inc. C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Fudan Univ, Dept Mat Sci, Shanghai 200433, Peoples R China. Chinese Acad Sci, Beijing Lab Electron Microscopy, Beijing 100080, Peoples R China. Univ Tennessee, Dept Biochem & Cellular & Mol Biol, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Wunderlich, B (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 15 TC 17 Z9 18 U1 1 U2 6 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 USA SN 0887-6266 J9 J POLYM SCI POL PHYS JI J. Polym. Sci. Pt. B-Polym. Phys. PD JAN 15 PY 1998 VL 36 IS 1 BP 105 EP 112 DI 10.1002/(SICI)1099-0488(19980115)36:1<105::AID-POLB12>3.0.CO;2-G PG 8 WC Polymer Science SC Polymer Science GA YV357 UT WOS:000071815100012 ER PT J AU Berger, EA Doms, RW Fenyo, EM Korber, BTM Littman, DR Moore, JP Sattentau, QJ Schuitemaker, H Sodroski, J Weiss, RA AF Berger, EA Doms, RW Fenyo, EM Korber, BTM Littman, DR Moore, JP Sattentau, QJ Schuitemaker, H Sodroski, J Weiss, RA TI A new classification for HIV-1 SO NATURE LA English DT Letter ID HUMAN-IMMUNODEFICIENCY-VIRUS; DISEASE PROGRESSION; INFECTION; INDIVIDUALS; RESISTANCE; PHENOTYPE C1 NIAID, Viral Dis Lab, NIH, Bethesda, MD 20892 USA. Univ Penn, Dept Pathol & Lab Med, Philadelphia, PA 19104 USA. Karolinska Inst, Microbiol & Tumorbiol Ctr, EC Concerted Act HIV Variat, S-17177 Stockholm, Sweden. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. NYU, Med Ctr, Howard Hughes Med Inst, New York, NY 10016 USA. Rockefeller Univ, Aaron Diamond AIDS Res Ctr, New York, NY 10016 USA. Ctr Immunol Marseille Luminy, F-13288 Marseille, France. Netherlands Red Cross, Blood Transfus Serv, Cent Lab, Dept Clin Viroimmunol, Amsterdam, Netherlands. Univ Amsterdam, Expt & Clin Immunol Lab, Amsterdam, Netherlands. Dana Farber Canc Inst, Dept Canc Immunol AIDS, Boston, MA 02115 USA. Inst Canc Res, Chester Beatty Labs, London SW3 6JB, England. RP Berger, EA (reprint author), NIAID, Viral Dis Lab, NIH, Bldg 4,Room 236, Bethesda, MD 20892 USA. NR 10 TC 617 Z9 635 U1 3 U2 18 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 15 PY 1998 VL 391 IS 6664 BP 240 EP 240 DI 10.1038/34571 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YR328 UT WOS:000071484400033 PM 9440686 ER PT J AU Jackson, P Mastrangelo, I Reed, M Tegtmeyer, P Yardley, G Barrett, J AF Jackson, P Mastrangelo, I Reed, M Tegtmeyer, P Yardley, G Barrett, J TI Synergistic transcriptional activation of the MCK promoter by p53: tetramers link separated DNA response elements by DNA looping SO ONCOGENE LA English DT Article DE p53; MCK; transcription; DNA looping ID TATA-BINDING PROTEIN; GENE; IDENTIFICATION; ENHANCER; SEQUENCE; DOMAINS; MUTANT; SITES; TRANSACTIVATION; SUPPRESSION AB The WAF1, Cyclin G and muscle creatine kinase (MCK) genes, all contain multiple copies of the consensus p53-binding element within their regulatory regions, We examined the role of these elements in transactivation of the muscle creatine kinase (MCK) gene by p53, The MCK promoter possesses distal (-3182 to -3133) and proximal (-177 to -81) p53-binding elements within which residues -3182 to -3151 (distal) and -176 to -149 (proximal) show homology to the consensus p53-binding site, Using promoter deletion studies, we find that both proximal and distal elements are required for high level, synergistic transcriptional activation in vivo. Electron microscopy indicates that p53-p53 interactions link proximal and distal p53-binding elements and cause looping out of intervening DNA, suggesting that this DNA sequence may be dispensable for synergy, This idea was confirmed by progressive deletion of the DNA between p53-binding elements, Synergism persisted with spacing reduced to only 150 bp, Tetramerization-deficient p53 mutants were defective for transcriptional activation but still capable of synergy, Our results provide evidence for a model by which high level transcriptional activation of promoters with multiple p53 response elements is achieved. C1 Prince Wales Hosp, Oncol Res Ctr, Randwick, NSW 2031, Australia. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. SUNY Stony Brook, Med Ctr, Dept Mol Genet & Microbiol, Stony Brook, NY 11794 USA. RP Jackson, P (reprint author), Prince Wales Hosp, Oncol Res Ctr, Randwick, NSW 2031, Australia. FU NCI NIH HHS [CA-18808, CA-28148] NR 47 TC 28 Z9 28 U1 1 U2 2 PU STOCKTON PRESS PI BASINGSTOKE PA HOUNDMILLS, BASINGSTOKE RG21 6XS, HAMPSHIRE, ENGLAND SN 0950-9232 J9 ONCOGENE JI Oncogene PD JAN 15 PY 1998 VL 16 IS 2 BP 283 EP 292 DI 10.1038/sj.onc.1201491 PG 10 WC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity SC Biochemistry & Molecular Biology; Oncology; Cell Biology; Genetics & Heredity GA YQ827 UT WOS:000071427100016 PM 9464547 ER PT J AU Payne, MG Deng, L Garrett, WR AF Payne, MG Deng, L Garrett, WR TI Third harmonic generation and destructive interference with femtosecond laser pulses SO OPTICS COMMUNICATIONS LA English DT Article ID RESONANCE; IONIZATION; SHIFTS; GAS AB With an unfocused femtosecond laser tuned to overlap three-photon resonance with a fine structure doublet, a third harmonic field is predicted which has a bandwidth much narrower than that of the laser. Consequently, this third harmonic field decays slowly with time, lasting as long as several nanoseconds. The population left in the excited states is suppressed by a destructive interference between different excitation pathways. (C) 1998 Elsevier Science B.V. C1 Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. Oak Ridge Natl Lab, Chem Phys Sect, Oak Ridge, TN 37831 USA. RP Payne, MG (reprint author), Georgia So Univ, Dept Phys, Statesboro, GA 30460 USA. RI Deng, Lu/B-3997-2012 NR 12 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0030-4018 J9 OPT COMMUN JI Opt. Commun. PD JAN 15 PY 1998 VL 146 IS 1-6 BP 257 EP 261 DI 10.1016/S0030-4018(97)00494-X PG 5 WC Optics SC Optics GA ZM329 UT WOS:000073527600051 ER PT J AU Nellis, WJ Louis, AA Ashcroft, NW AF Nellis, WJ Louis, AA Ashcroft, NW TI Metallization of fluid hydrogen SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article DE hydrogen; metallization of hydrogen; liquid metallic hydrogen; insulator-metal transition ID MOLECULAR-HYDROGEN; ELECTRICAL-CONDUCTIVITY; MEGABAR PRESSURES; SHOCK COMPRESSION; SOLID HYDROGEN; DENSE HYDROGEN; TRANSITIONS; DEUTERIUM; EQUATION; STATE AB The electrical resistivity of liquid hydrogen has been measured at the high dynamic pressures, densities and temperatures that can be achieved with a reverberating shock wave. The resulting data are most naturally interpreted in terms of a continuous transition from a semiconducting to a metallic largely diatomic fluid, the latter at 140 GPa (nine-fold compression) and 3000 K. While the fluid at these conditions resembles common liquid metals by the scale of its resistivity of 500 mu Omega cm, it differs by retaining a strong pairing character, and the precise mechanism by which a metallic state might be attained is still a matter of debate. Some evident possibilities include: (i) physics of a largely one-body character, such as a band-overlap transition; (ii) physics of a strong-coupling or many-body character, such as a Mott-Hubbard transition; and (iii) processes in which structural changes are paramount. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Cornell Univ, Atom & Solid State Phys Lab, Ithaca, NY 14853 USA. RP Nellis, WJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 69 TC 39 Z9 40 U1 3 U2 8 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 15 PY 1998 VL 356 IS 1735 BP 119 EP 135 DI 10.1098/rsta.1998.0153 PG 17 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YW096 UT WOS:000071896300015 ER PT J AU Rao, CNR Iye, Y McGreevy, R Edwards, PP Nellis, WJ Tunstall, DP AF Rao, CNR Iye, Y McGreevy, R Edwards, PP Nellis, WJ Tunstall, DP TI Magnetic field-induced metal-insulator transitions in graphite and diluted magnetic semiconductors - Discussion SO PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Editorial Material C1 Indian Inst Sci, Bangalore 560012, Karnataka, India. Univ Birmingham, Sch Chem, Birmingham B15 2TT, W Midlands, England. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9AJ, Fife, Scotland. RP Rao, CNR (reprint author), Indian Inst Sci, Bangalore 560012, Karnataka, India. RI Rao, C.N.R./B-1569-2009; Ahirwal, Ashish /F-2532-2013 OI Rao, C.N.R./0000-0003-4088-0615; Ahirwal, Ashish /0000-0002-9127-6541 NR 0 TC 0 Z9 0 U1 0 U2 0 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-503X J9 PHILOS T R SOC A JI Philos. Trans. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 15 PY 1998 VL 356 IS 1735 BP 171 EP 172 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YW096 UT WOS:000071896300020 ER PT J AU Soderlind, P Wills, JM Eriksson, O AF Soderlind, P Wills, JM Eriksson, O TI Simple model for complex structures SO PHYSICAL REVIEW B LA English DT Article ID CRYSTAL-STRUCTURE; BULK PROPERTIES; PHASE-DIAGRAM; BAND; SYSTEMS; METALS AB The complex structures of the low-temperature phases of light actinides are analyzed in terms of a simple model involving Pettifor's structural energy difference theorem in combination with an estimate of the structural dependence of the electrostatic interaction in the solid. With this simple model the complex structures of the actinides are contrasted to the simpler ones of the transition metals, and in agreement with observations we find that at ambient conditions the f-electron elements favor distorted structures, whereas d-electron metals "prefer" cubic or hcp structures. C1 Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87544 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87544 USA. RP Soderlind, P (reprint author), Lawrence Livermore Natl Lab, Dept Phys, Livermore, CA 94550 USA. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 23 TC 21 Z9 21 U1 1 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1320 EP 1323 DI 10.1103/PhysRevB.57.1320 PG 4 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800005 ER PT J AU Kiryukhin, V Casa, D Keimer, B Hill, JP Higgins, MJ Bhattacharya, S AF Kiryukhin, V Casa, D Keimer, B Hill, JP Higgins, MJ Bhattacharya, S TI X-ray-scattering study of the charge-density-wave structure in NbSe3 in high magnetic fields SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; PHASE-TRANSITION AB An upper bound of Delta q/q less than or equal to 2.5x10(-3) on the magnetic-field-induced shift of the wave vector of the low temperature charge-density wave in NbSe3 is established by high-resolution x-ray diffraction in magnetic fields up to 10 T. The charge-density-wave order parameter is also magnetic-field independent, to within 10%. These limits are discussed in the context of magnetotransport experiments on NbSe3 as well as theoretical models that had predicted a magnetic-field dependence of the charge-density-wave structure. C1 Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NEC Res Inst, Princeton, NJ 08540 USA. RP Kiryukhin, V (reprint author), Princeton Univ, Dept Phys, Princeton, NJ 08544 USA. RI Casa, Diego/F-9060-2016 NR 26 TC 13 Z9 13 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1332 EP 1335 DI 10.1103/PhysRevB.57.1332 PG 4 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800008 ER PT J AU Zhang, JM Giehler, M Gobel, A Ruf, T Cardona, M Haller, EE Itoh, K AF Zhang, JM Giehler, M Gobel, A Ruf, T Cardona, M Haller, EE Itoh, K TI Optical phonons in isotopic Ge studied by Raman scattering SO PHYSICAL REVIEW B LA English DT Article ID TEMPERATURE-DEPENDENCE; GERMANIUM; SEMICONDUCTORS; DISORDER; DENSITY; SI AB The effects of isotopic substitution on the T-point phonon in isotopically enriched (Ge-70, Ce-73, Ge-74, and Ce-76) and disordered (natural Ge and Ge-70/76) germanium samples have been measured with Ranan spectroscopy. We believe. in contrast to earlier work: that intrinsic bulk Raman phonons are observed only when surface oxides are removed by chemical etching, and a laser line In the red is used to greatly enhance the penetration depth of the light. In high-resolution experiments at 10 K, performed under these conditions, we obtain more precise phonon frequencies and find significantly reduced phonon linewidths than reported before. Our observations improve on previous results. and are in better agreement with predictions of coherent-potential-approximation and supercell calculations. C1 Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany. Univ Calif Berkeley, Berkeley, CA 94720 USA. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Zhang, JM (reprint author), Max Planck Inst Festkorperforsch, Heisenbergstr 1, D-70569 Stuttgart, Germany. RI Itoh, Kohei/C-5738-2014 NR 24 TC 68 Z9 68 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1348 EP 1351 DI 10.1103/PhysRevB.57.1348 PG 4 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800012 ER PT J AU Cho, JH Zhang, ZY Lee, SH Kang, MH AF Cho, JH Zhang, ZY Lee, SH Kang, MH TI Geometry and core-level shifts of an adsorbed Sb monolayer on GaAs(110) SO PHYSICAL REVIEW B LA English DT Article ID ELECTRONIC-STRUCTURE; SB/GAAS(110) INTERFACE; SURFACE; PSEUDOPOTENTIALS; ANTIMONY; STATE; WAVE AB The atomic geometry and the core-level. shifts of an Sb monolayer adsorbed on the GaAs(110) surface have been determined using the pseudopotential density-functional theory, The results clearly favor the epitaxial continued layer structure (ECLS) model, and demonstrate the need to include the Ga partial-core correction for both the GaAs bulk lattice constant and the Sb-Ga bond length. Furthermore, within the ECLS geometry, both the initial- and the final-state model calculations lead to the same conclusion that the 4d core-level binding energy of an Sb atom bonded to Ga shifts downwards by about 0.4 eV relative to that of an Sb bonded to As. These findings provide the theoretical basis For the interpretation of recent photoelectron diffraction experiments. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. Univ Tennessee, Dept Phys & Astron, Knoxville, TN 37996 USA. Pohang Univ Sci & Technol, Dept Phys, Pohang 790784, South Korea. RP Cho, JH (reprint author), Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RI Lee, Sung-Hoon/A-9582-2011; Cho, Jun-Hyung/R-7256-2016 OI Lee, Sung-Hoon/0000-0002-8553-8007; Cho, Jun-Hyung/0000-0002-1785-1835 NR 22 TC 13 Z9 13 U1 1 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1352 EP 1355 DI 10.1103/PhysRevB.57.1352 PG 4 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800013 ER PT J AU Zachar, O Kivelson, SA Emery, VJ AF Zachar, O Kivelson, SA Emery, VJ TI Landau theory of stripe phases in cuprates and nickelates SO PHYSICAL REVIEW B LA English DT Article ID 2-DIMENSIONAL HUBBARD-MODEL; MONTE-CARLO; HEISENBERG-ANTIFERROMAGNET; DOPED ANTIFERROMAGNET; LONG-RANGE; CHARGE; HOLES; SPINS; SUPERCONDUCTIVITY; FLUCTUATIONS AB We consider a Landau theory of coupled charge and spin-density-wave order parameters as a simple model for the ordering that has been observed experimentally in the La2NiO4 and La2CuO4 families of doped antiferromagnets. The period or the charge-density wave is generically half that of the spin-density wave. or equivalently the charges form antiphase domain walls in the antiferromagnetic order. A sharp distinction exists between the case in which the ordering is primarily charge driven (which produces a sequence of transitions in qualitative agreement with experiment) or spin driven (which does not). We also find that stripes with non-collinear spin order (i.e., spiral phases) are possible in a region of the phase diagram a here the transition is spin driven; the spiral is circular only when there is no charge order, and is otherwise elliptical with an eccentricity proportional to the magnitude of the charge order. C1 Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Zachar, O (reprint author), Univ Calif Los Angeles, Dept Phys, Los Angeles, CA 90095 USA. NR 38 TC 136 Z9 137 U1 5 U2 23 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1422 EP 1426 DI 10.1103/PhysRevB.57.1422 PG 5 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800031 ER PT J AU Springborg, M Albers, RC Schmidt, K AF Springborg, M Albers, RC Schmidt, K TI Fractional occupancies and temperature in electronic-structure calculations SO PHYSICAL REVIEW B LA English DT Article ID 1ST-PRINCIPLES MOLECULAR-DYNAMICS; DENSITY-FUNCTIONAL ENERGIES; LINEAR COMBINATION; ORBITALS; OCCUPATIONS; GRADIENTS; FORCES AB Fractional occupancies are often used in electronic-structure calculations. We use a simple model that contains the essential elements of more elaborate first-principles techniques in order to evaluate the effects of four typical fractional occupancy schemes on a system's calculated physical properties. We find that when the broadenings used in such a scheme are not significantly larger than the characteristic energies of the system of interest, the results depend only marginally on the type of broadening function that is used, except for Lorentzian broadening. We have also studied differences between free-energy and total-energy formulations. Finally, we present closed formulas for those parts of the forces that originate from the fractional occupancies, both for our model and for electronic-structure calculations within the density-functional formalism. Based on our results, we recommend using a simple step-function broadening scheme, which, unlike some more common methods, does not require a highly nonlinear equation to be iteratively solved for the Fermi energy. C1 Univ Konstanz, Dept Chem, D-78457 Constance, Germany. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Konstanz, Dept Chem, D-78457 Constance, Germany. NR 23 TC 12 Z9 12 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1427 EP 1435 DI 10.1103/PhysRevB.57.1427 PG 9 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800032 ER PT J AU Haas, H Wang, CZ Fahnle, M Elsasser, C Ho, KM AF Haas, H Wang, CZ Fahnle, M Elsasser, C Ho, KM TI Environment-dependent tight-binding model for molybdenum SO PHYSICAL REVIEW B LA English DT Article ID GROUND-STATE PROPERTIES; TOTAL-ENERGY METHOD; TRANSITION-METALS; NOBLE-METALS; SURFACE; MO(001); 4D-TRANSITION; POTENTIALS; CONSTANTS; VACANCIES AB A transferable orthogonal tight-binding model is developed for molybdenum, with special emphasis on applications in molecular-dynamics studies. The elements of the Hamiltonian matrix and the repulsive potential are allowed to depend on the environment in order to account for the effects of the neglected three center matrix elements, for the neglected nonorthogonality effects and for the variation of the finite set of basis orbitals in different configurations as well. To check the accuracy of the model, the structural energy differences, the elastic constants, the phonon spectrum along high-symmetry lines in the Brillouin zone, the formation and migration energy of a vacancy, the formation energy of an octahedral interstitial atom, surface energies, and relaxations, as well as reconstructions of a (100) surface, are calculated and compared with ab initio data and experimental results. C1 Max Planck Inst Met Res, D-70569 Stuttgart, Germany. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Phys, Ames, IA 50011 USA. Max Planck Inst Met Res, D-70174 Stuttgart, Germany. RP Max Planck Inst Met Res, Heisenbergstr 1, D-70569 Stuttgart, Germany. NR 52 TC 53 Z9 53 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1461 EP 1470 DI 10.1103/PhysRevB.57.1461 PG 10 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800036 ER PT J AU Kurmaev, EZ Stadler, S Ederer, DL Harada, Y Shin, S Grush, MM Callcott, TA Perera, RCC Zatsepin, DA Ovechkina, N Kasai, M Tokura, Y Takahashi, T Chandrasekaran, K Vijayaraghavan, R Varadaraju, UV AF Kurmaev, EZ Stadler, S Ederer, DL Harada, Y Shin, S Grush, MM Callcott, TA Perera, RCC Zatsepin, DA Ovechkina, N Kasai, M Tokura, Y Takahashi, T Chandrasekaran, K Vijayaraghavan, R Varadaraju, UV TI Electronic structure of Sr2RuO4: X-ray fluorescence emission study SO PHYSICAL REVIEW B LA English DT Article ID NONCUPRATE SUPERCONDUCTOR SR2RUO4; EXTENDED VANHOVE SINGULARITY; LAYERED PEROVSKITE; UNDULATOR BEAMLINE; SPECTROSCOPY; EXCITATION AB The results of measurements of O 1s total x-ray-fluorescence yield and Ru N-2,N-3 and O K-alpha x-ray fluorescence emission spectra of Sr2RuO4 and Sr2Ru4.25 are presented. An excitation energy dependence of the O K-alpha x-ray emission spectra (XES) was observed in both compounds. The energy dependence of the spectra is attributed to the excitation of inequivalent O(1) in-plant and O(2) apical oxygens. The O(1) 2p and O(2) 2p density of states distribution in the valence band of Sr2RuO4 was found to be different in accordance with the results of band-structure calculations. O(1) 2p states are found to be mixed with Ru 4d(t(2g) states providing the formation of pi bonds. While the O K-alpha XES spectra are in fair agreement with hand structure calculations, the theoretical two-peak distribution of Ru N-2,N-3 XES is found to be different with respect to the intensity ratios and widths of the peaks of Ru N-2,N-3 XES. These differences an attributed to a decrease of intensity of radiative 4d --> 4p transitions in the vicinity of the Fermi level (where the localization of Ru 4d states is higher than at the bottom of the valence band) due to a strong Kuster-Kronig transition. C1 Russian Acad Sci, Inst Met Phys, Yekaterinburg 620219, Russia. Tulane Univ, Dept Phys, New Orleans, LA 70118 USA. Univ Tokyo, Inst Solid State Phys, Synchrotron Radiat Lab, Tokyo 188, Japan. Univ Tennessee, Dept Phys, Knoxville, TN 37996 USA. Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Univ Tokyo, Dept Appl Phys, Tokyo 113, Japan. Tohoku Univ, Dept Phys, Sendai, Miyagi 98077, Japan. Indian Inst Technol, MSRC, Madras 600036, Tamil Nadu, India. RP Kurmaev, EZ (reprint author), Russian Acad Sci, Inst Met Phys, GSP-170, Yekaterinburg 620219, Russia. RI Takahashi, Takashi/E-5080-2010; Tokura, Yoshinori/C-7352-2009; Kurmaev, Ernst/J-4254-2013; Zatsepin, Dmitry/F-5520-2012 OI Kurmaev, Ernst/0000-0003-4625-4930; NR 21 TC 25 Z9 26 U1 0 U2 6 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1558 EP 1562 DI 10.1103/PhysRevB.57.1558 PG 5 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800048 ER PT J AU Kellar, SA Chen, Y Huff, WRA Moler, EJ Hussain, Z Shirley, DA AF Kellar, SA Chen, Y Huff, WRA Moler, EJ Hussain, Z Shirley, DA TI Surface structure determination of Au(1 ML) Fe(15 ML) Au(100) using angle-resolved photoemission extended fine structure SO PHYSICAL REVIEW B LA English DT Article ID MAGNETIC-STRUCTURE; ADSORBATE-GEOMETRY; PHOSPHORUS; FE(001); GROWTH; FILMS; FE; DIFFRACTION; RELAXATION; MONOLAYER AB We have determined the atomic surface structure of a thin film of Fe (15 ML) grown On the Au(100) surface, Au(1 ML)/Fe(15 ML)/Au(100), with angle-resolved photoemission extended fine structure (ARPEFS) using the Au 4f(7/2) core level. We have confirmed that a bcc crystalline Fe film grows epitaxially on the Au(100) substrate with 1 ML or Au atoms remaining on the surface using angle-resolved photoemission spectroscopy. We analyzed the ARPEFS oscillations using an electron-scattering code based on the Rehr-Albers scattering matrix formalism. Our analysis finds that the surface Au atoms are positioned in the fourfold hollow sites 1.67 +/- 0.02 Angstrom above the Fe surface. We also find that the grown Fe layers are very like bulk bcc Fe, with an interlayer spacing of 1.43 +/- 0.03 Angstrom. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Adv Light Source, Berkeley, CA 94720 USA. Penn State Univ, Dept Chem, University Pk, PA 16802 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. RP Kellar, SA (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. NR 37 TC 7 Z9 7 U1 0 U2 0 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 3 BP 1890 EP 1895 DI 10.1103/PhysRevB.57.1890 PG 6 WC Physics, Condensed Matter SC Physics GA YU434 UT WOS:000071716800093 ER PT J AU Ravindran, P Nordstrom, L Ahuja, R Wills, JM Johansson, B Eriksson, O AF Ravindran, P Nordstrom, L Ahuja, R Wills, JM Johansson, B Eriksson, O TI Theoretical investigation of the high-pressure phases of Ce SO PHYSICAL REVIEW B LA English DT Article ID GENERALIZED GRADIENT APPROXIMATION; CRYSTAL-STRUCTURE STABILITIES; SPIN-DENSITY APPROXIMATION; GROUND-STATE PROPERTIES; ALPHA-GAMMA-TRANSITION; KONDO VOLUME-COLLAPSE; ELECTRONIC-STRUCTURE; CERIUM METAL; GAMMA->ALPHA TRANSITION; ORBITAL POLARIZATION AB In order to shed light on the recent experimental controversy concerning the intermediate pressure phases of Ce we have made systematic electronic structure and total-energy studies on Ce in the experimentally reported low-pressure phase alpha-Ce (fcc), the intermediate-pressure alpha-U (alpha'), the body-centered monoclinic [alpha "(I)], and C-face-centered monoclinic [alpha "(II)] phases, together with the stable high-pressure body-centered tetragonal phase. We also included the body-centered cubic, hexagonal-close-packed, and omega (hP3) phases. In this study we used the accurate full-potential linear muffin-tin orbital (FPLMTO) method. The optimized structural parameters obtained from our total-energy studies for the alpha' and alpha "(II) phases are found to be in good agreement with corresponding experimental values. The structural optimization of the alpha "(I) phase always yields the fee or bet phase stable, depending upon the volume considered. Except for an improvement in the equilibrium volume, the generalized gradient correction reproduces the calculated relative stability between different phases of Ce at high pressure of the local-density approximation. Of the experimentally reported intermediate pressure structures [alpha', alpha "(I) and alpha "(II)] we find that the alpha "(II) phase is the most stable. Among the contending phases, alpha' and alpha "(I), the latter is very close in energy to the alpha " phase whereas the former is substantially higher in energy. We thus rule out the alpha-U structure as an intermediate pressure phase of Ce. Our work suggests that the most probable structural phase transition sequence of Ce metal is fcc(gamma)-->fcc(alpha)-->alpha "(II)-->bct, which is consistent with current experimental results. C1 Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. Univ Calif Los Alamos Natl Lab, Ctr Mat Sci, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Ravindran, P (reprint author), Univ Uppsala, Dept Phys, Condensed Matter Theory Grp, Box 530, S-75121 Uppsala, Sweden. RI Eriksson, Olle/E-3265-2014 OI Eriksson, Olle/0000-0001-5111-1374 NR 62 TC 21 Z9 21 U1 1 U2 7 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 4 BP 2091 EP 2101 DI 10.1103/PhysRevB.57.2091 PG 11 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900023 ER PT J AU Wolverton, C Zunger, A AF Wolverton, C Zunger, A TI Cation and vacancy ordering in LixCoO2 SO PHYSICAL REVIEW B LA English DT Article ID LASER-ABLATION DEPOSITION; PHASE-DIAGRAMS; 1ST-PRINCIPLES CALCULATION; SPECIAL POINTS; LICOO2; DENSITY; SYSTEMS; OXIDES; SPINEL; ALLOYS AB Using a combination of first-principles total energies, a cluster expansion technique, and Monte Carlo simulations. we have studied the Li/Co ordering in LiCoO2 and Li-vacancy/Co ordering in the square CoO2. We find: (i) A ground-state search of the space of substitutional cation configurations yields the CuPt structure as the lowest-energy state in the octahedral system LiCoO2 (and square CoO2), in agreement with the experimentally observed phase. (ii) Finite-temperature calculations predict that the solid-state order-disorder transitions for LiCoO2 and square CoO2 occur at temperatures (similar to 5100 K and similar to 4400 K, respectively) much higher than melting, thus making these transitions experimentally inaccessible. (iii) The energy of the reaction E-tot(sigma,LiCoO2) - E-tot(sigma,square CoO2) - E-tot(Li,bcc) gives the average battery voltage (V) over bar of a LixCoO2/Li cell for the cathode in the structure a. Searching the space of configurations a for large average voltages,we find that sigma = CuPt [a monolayer [111] superlattice] has a high voltage ((V) over bar = 3.78 V), but that this could be increased by cation randomization ((V) over bar = 3.99 V), by partial disordering ((V) over bar = 3.86 V), or by forming a two-layer Li2Co2O4 superlattice along [111] ((V) over bar = 4.90 V). C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Wolverton, C (reprint author), Natl Renewable Energy Lab, Golden, CO 80401 USA. RI Wolverton, Christopher/B-7542-2009; Zunger, Alex/A-6733-2013 NR 41 TC 103 Z9 106 U1 5 U2 59 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 4 BP 2242 EP 2252 DI 10.1103/PhysRevB.57.2242 PG 11 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900041 ER PT J AU Biswas, R Li, QM Pan, BC Yoon, Y AF Biswas, R Li, QM Pan, BC Yoon, Y TI Mechanism for hydrogen diffusion in amorphous silicon SO PHYSICAL REVIEW B LA English DT Article ID A-SI-H; MOTION AB Tight-binding molecular-dynamics calculations reveal a mechanism for hydro en diffusion in hydrogenated amorphous silicon. Hydrogen diffuses through the network by successively bonding with nearby silicons and breaking their Si-Si bonds. The diffusing hydrogen carries with it a newly created dangling bond. These intermediate transporting states are densely populated in the network, have lower energies than H at the center of stretched Si-Si bonds, and can play a crucial role in hydrogen diffusion. C1 Iowa State Univ, Dept Phys, Microelect Res Ctr, Ames, IA 50011 USA. Iowa State Univ, US DOE, Ames Lab, Ames, IA 50011 USA. RP Biswas, R (reprint author), Iowa State Univ, Dept Phys, Microelect Res Ctr, Ames, IA 50011 USA. RI Pan, Bicai/A-1235-2010 NR 17 TC 42 Z9 43 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 4 BP 2253 EP 2256 DI 10.1103/PhysRevB.57.2253 PG 4 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900042 ER PT J AU Windl, W Sankey, OF Menendez, J AF Windl, W Sankey, OF Menendez, J TI Theory of strain and electronic structure of Si1-yCy and Si1-x-yGexCy alloys SO PHYSICAL REVIEW B LA English DT Article ID MOLECULAR-BEAM EPITAXY; INTERSTITIAL-CARBON; SEMICONDUCTOR ALLOYS; ELASTIC PROPERTIES; SI1-XGEX ALLOYS; SOLID-SOLUTIONS; MONTE-CARLO; SILICON; SI(001); RELAXATION AB We examine the strain-composition relation and band gap/deep-level properties of Si1-x-yGexCy alloys using a local-orbital density-functional scheme. For purely substitutional carbon, a strong nonlinearity in the dependence of the bulk-alloy lattice constant on the concentration is found. In the linear regime of small carbon concentrations, this leads to a much more rapid decrease of the lattice constant with carbon concentration than predicted by Vegard's law. A comparison of our dependence of the lattice constants in Si1-xGex and Si1-yCy alloys on the concentrations suggests a germanium-carbon strain compensation ratio of(15 +/- 3):1. This ratio is found to decrease when interstitial carbon is present. These results are compared with recent experiments, where the strain as well as the fraction of interstitial carbon have been measured. We also examine the band structure of Si1-yCy alloys in the technically interesting concentration range of a few percent carbon. We find that the carbon-induced states are highly localized, and can form a deep level in the band gap of silicon. We show that these findings are an important step toward an understanding of recent experimental photoluminescence spectra. C1 Arizona State Univ, Ctr Solid State Sci, Tempe, AZ 85287 USA. Arizona State Univ, Dept Phys & Astron, Tempe, AZ 85287 USA. RP Windl, W (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. EM windl@tl2.lanl.gov RI Menendez, Jose/C-1034-2009; Windl, Wolfgang/C-7255-2012 OI Menendez, Jose/0000-0001-8739-9197; Windl, Wolfgang/0000-0001-5892-0684 NR 80 TC 45 Z9 45 U1 1 U2 10 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 4 BP 2431 EP 2442 DI 10.1103/PhysRevB.57.2431 PG 12 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900067 ER PT J AU Alatalo, M Weinert, M Watson, RE AF Alatalo, M Weinert, M Watson, RE TI Stability of Zr-Al alloys SO PHYSICAL REVIEW B LA English DT Article ID PSEUDOPOTENTIALS; ALUMINUM; L12 AB The Zr-Al alloy system has one of the more complicated binary transition-metal aluminide phase diagrams: ten reported intermediate phases belonging to four different crystal systems. In order to understand the competition among different structures and concentrations, the heats of formation of a number of different possible structures were calculated using both all-electron and pseudopotential methods. The Zr5Al3 (tI32) and Zr5Al4 (hP18) phases are predicted to be high-temperature phases. The existence of the large number of observed phases is attributed to the fact that the heats of formation for ZrxAl1-x for x = 0.25-0.75 fall on a nearly straight line, suggesting that these phases should have narrow composition ranges. In addition, a simple procedure to modify and test the pseudopotentials is presented and shown to yield calculated metallic alloy properties in good agreement with the all-electron results. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Alatalo, M (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 20 TC 20 Z9 21 U1 0 U2 1 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 1098-0121 EI 1550-235X J9 PHYS REV B JI Phys. Rev. B PD JAN 15 PY 1998 VL 57 IS 4 BP R2009 EP R2012 DI 10.1103/PhysRevB.57.R2009 PG 4 WC Physics, Condensed Matter SC Physics GA YV536 UT WOS:000071834900003 ER PT J AU Bloom, ED Wells, JD AF Bloom, ED Wells, JD TI Multi-GeV photons from electron-dark-matter scattering near active galactic nuclei SO PHYSICAL REVIEW D LA English DT Article ID GAMMA-RAYS; EMISSION; BLAZARS; GALAXY; MODEL AB Active galactic nuclei (AGN) may emit highly collimated and intense jets of relativistic electrons which upscatter ambient photons. These electrons can also scatter off the cold dark matter halo of the galaxy to produce high energy photons which have a more isotropic signature than the upscattered photons from QED processes. We propose to look for these high energy photons coming from AGN as a method to detect dark matter. As a primary example we work out the expected signal from electrons scattering off the lightest supersymmetric partner into a photon plus selectron. Using the optimistic side of astrophysical uncertainties, we still find the signal from M87 or Centaurus A, two close-by AGN, smaller than the sensitivities expected of the currently proposed photon detectors. However, long running photon detectors and future detectors of higher sensitivity might be able to distinguish a signal from AGN sources. In order to have confidence that new physics sources are discernible, we also emphasize the importance of multiwavelength studies of AGN with varying jet axis orientation to the Earth. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. NR 37 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 2470-0010 EI 2470-0029 J9 PHYS REV D JI Phys. Rev. D PD JAN 15 PY 1998 VL 57 IS 2 BP 1299 EP 1302 DI 10.1103/PhysRevD.57.1299 PG 4 WC Astronomy & Astrophysics; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YU015 UT WOS:000071671300065 ER PT J AU Beausang, CW Fallon, P Appelbe, DE Aztalos, S Clark, RM Clarke, S Cederwall, B Deleplanque, MA Diamond, RM Erturk, S Kelly, W Lee, IY Macchaivelli, AO Patterson, DC Smith, MB Stephens, FS Twin, PJ Wilson, AN AF Beausang, CW Fallon, P Appelbe, DE Aztalos, S Clark, RM Clarke, S Cederwall, B Deleplanque, MA Diamond, RM Erturk, S Kelly, W Lee, IY Macchaivelli, AO Patterson, DC Smith, MB Stephens, FS Twin, PJ Wilson, AN TI Lifetimes of yrast and excited superdeformed states in Gd-150: effect of particle-hole excitations on the deformation SO PHYSICS LETTERS B LA English DT Article ID BANDS AB The quadrupole moments and deformations have been measured for six superdeformed bands in Gd-150. The results indicate evidence for deformation driving properties of both the high-hi intruder and also low-N natural parity states at the superdeformed Fermi surface. Several new transitions have been identified and placed in the low spin non-yrast portion of one of the SD bands. (C) 1998 Published by Elsevier Science B.V. C1 Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. Yale Univ, Wright Nucl Struct Lab, New Haven, CT 06511 USA. Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Royal Inst Technol, S-10044 Stockholm, Sweden. Iowa State Univ, Ames, IA 50011 USA. RP Beausang, CW (reprint author), Univ Liverpool, Oliver Lodge Lab, Liverpool L69 3BX, Merseyside, England. RI Cederwall, Bo/M-3337-2014; OI Cederwall, Bo/0000-0003-1771-2656; Smith, Martin/0000-0003-0834-1574; Wilson, Anna/0000-0001-6928-1689 NR 18 TC 11 Z9 11 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 15 PY 1998 VL 417 IS 1-2 BP 13 EP 19 DI 10.1016/S0370-2693(97)01347-6 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YY923 UT WOS:000072201500003 ER PT J AU Dvali, G Riotto, A AF Dvali, G Riotto, A TI Minimalism in inflation model building SO PHYSICS LETTERS B LA English DT Article ID D-TERMS; HYBRID INFLATION; SUPERSYMMETRY; SUPERGRAVITY; SUPERSTRINGS; CONSTRAINTS AB In this paper we demand that a successful inflationary scenario should follow from a model entirely motivated by particle physics considerations. We show that such a connection is indeed possible within the framework of concrete supersymmetric Grand Unified Theories where the doublet-triplet splitting problem is naturally solved. The Fayet-Iliopoulos D-term of a gauge U(1)(xi) symmetry, which plays a crucial role in the solution of the doublet-triplet splitting problem, simultaneously provides a built-in inflationary slope protected from dangerous supergravity corrections. (C) 1998 Published by Elsevier Science B.V. C1 CERN, Div Theory, CH-1211 Geneva, Switzerland. NASA, Fermi Natl Accelerator Lab, Fermilab Astrophys Ctr, Batavia, IL 60510 USA. RP Dvali, G (reprint author), CERN, Div Theory, CH-1211 Geneva, Switzerland. NR 29 TC 18 Z9 18 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 15 PY 1998 VL 417 IS 1-2 BP 20 EP 26 DI 10.1016/S0370-2693(97)01357-9 PG 7 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YY923 UT WOS:000072201500004 ER PT J AU Brodsky, SJ Huet, P AF Brodsky, SJ Huet, P TI Aspects of SU(N-c) gauge theories in the limit of small number of colors SO PHYSICS LETTERS B LA English DT Article AB We investigate properties of the color space of SU(N-c) gauge theories in the limit of small numbers (N-c-->0) and large number of flavors. More generally, we introduce a rescaling of alpha(s) and n(f) which assigns a finite limit to colored quantities as N-c-->O, which reproduces their known large-n(c) limit, and which expresses them as an analytic function of N-c(2) for arbitrary value of N-c. The vanishing-N-c limit has an Abelian character and is also the small-N-c limit of [U(1)](Nc-1). This limit does not have an obvious quantum field theory interpretation; however, it provides practical consistency checks on QCD perturbative quantities by comparing them to their QED counterparts. Our analysis also describes the two-dimensional topological structure involved in the interpretation of the small N-c-limit in color space. (C) 1998 Elsevier Science B.V. C1 Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Univ Calif Santa Cruz, Inst Particle Phys, Santa Cruz, CA 95064 USA. RP Brodsky, SJ (reprint author), Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. EM sjbth@slac.stanford.edu; huet@scipp.ucsc.edu NR 14 TC 37 Z9 37 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 15 PY 1998 VL 417 IS 1-2 BP 145 EP 153 DI 10.1016/S0370-2693(97)01209-4 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YY923 UT WOS:000072201500023 ER PT J AU Bagan, E Ball, P Braun, VM AF Bagan, E Ball, P Braun, VM TI Radiative corrections to the decay B ->pi e nu and the heavy quark limit SO PHYSICS LETTERS B LA English DT Article ID QCD SUM-RULES; PION WAVE-FUNCTION; EXCLUSIVE PROCESSES; FORM-FACTORS; QUANTUM CHROMODYNAMICS; ASYMPTOTIC-BEHAVIOR; MESON DECAYS; B-DECAYS; FACTORIZATION; MODEL AB We calculate radiative corrections to the light-cone sum rule for the semileptonic form factor in B --> pi ev decays and thus remove the major uncertainty in determining the CKM mixing angle \V-ub\ by this method. We discuss the remaining uncertainties and perspectives for further studies. The structure of the radiative corrections suggests factorization of soft (end-point) and hard rescattering contributions in heavy-to-light decays in the heavy quark limit. (C) 1998 Elsevier Science B.V. C1 Autonomous Univ Barcelona, Dept Fis, Fis Teor Grp, E-08193 Bellaterra, Spain. Autonomous Univ Barcelona, Inst Fis Altes Energies, E-08193 Bellaterra, Spain. Fermi Natl Accelerator Lab, Batavia, IL 60510 USA. NORDITA, DK-2100 Copenhagen, Denmark. RP Bagan, E (reprint author), Autonomous Univ Barcelona, Dept Fis, Fis Teor Grp, E-08193 Bellaterra, Spain. NR 34 TC 109 Z9 109 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 15 PY 1998 VL 417 IS 1-2 BP 154 EP 162 DI 10.1016/S0370-2693(97)01371-3 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YY923 UT WOS:000072201500024 ER PT J AU Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cramer, O Crowe, KM Crede, V Degener, T Djaoshvili, N von Dombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Haddock, RP Heinsius, FH Heinzelman, M Herbstrith, A Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Kurilla, U Lakata, M Landua, R Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R Ould-Saada, F Peters, K Pick, B Pietra, C Pinder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Suh, JS Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D Wiedner, U Wittmack, K Zou, BS AF Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cramer, O Crowe, KM Crede, V Degener, T Djaoshvili, N von Dombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Haddock, RP Heinsius, FH Heinzelman, M Herbstrith, A Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Kurilla, U Lakata, M Landua, R Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R Ould-Saada, F Peters, K Pick, B Pietra, C Pinder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Suh, JS Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D Wiedner, U Wittmack, K Zou, BS CA Crystal Barrel Collaboration TI Decay dynamics of the process eta -> 3 pi(0) SO PHYSICS LETTERS B LA English DT Article AB The parameter alpha -0.052 +/- 0.020 describing the shape of the eta --> 3 pi(0) Dalitz plot has been determined using the data from the Crystal Barrel detector at LEAR. The value is compared to predictions of chiral perturbation theory. (C) 1998 Elsevier Science B.V. C1 Univ Karlsruhe, Karlsruhe, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. Univ Bonn, D-53115 Bonn, Germany. Hungarian Acad Sci, H-1525 Budapest, Hungary. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CERN, CH-1211 Geneva 4, Switzerland. Univ Hamburg, D-22761 Hamburg, Germany. Univ London Queen Mary & Westfield Coll, London E1 4NS, England. Univ Calif Los Angeles, Los Angeles, CA 90024 USA. Univ Munich, D-80333 Munich, Germany. Univ Ljubljana, Ljubljana, Slovenia. Silesian Univ, Katowice, Poland. Univ Karlsruhe, D-76021 Karlsruhe, Germany. LPHNE Paris 6, F-75252 Paris, France. LPHNE Paris 7, F-75252 Paris, France. Carnegie Mellon Univ, Pittsburgh, PA 15213 USA. Ctr Rech Nucl, F-67037 Strasbourg, France. Univ Zurich, CH-8057 Zurich, Switzerland. RP Abele, A (reprint author), Univ Karlsruhe, Kaiserstr 12, Karlsruhe, Germany. RI Meyer, Curtis/L-3488-2014 OI Meyer, Curtis/0000-0001-7599-3973 NR 7 TC 30 Z9 30 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 15 PY 1998 VL 417 IS 1-2 BP 193 EP 196 DI 10.1016/S0370-2693(97)01377-4 PG 4 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YY923 UT WOS:000072201500029 ER PT J AU Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cramer, O Crede, V Crowe, KM Degener, T Djaoshvili, N von Dombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Haddock, RP Heinsius, FH Heinzelmann, M Herbstrith, A Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Kurilla, U Lakata, M Landua, R Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R Ould-Saada, F Peters, K Pick, B Pietra, C Pinder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D WIedner, U Wittmack, K Zou, BS AF Abele, A Adomeit, J Amsler, C Baker, CA Barnett, BM Batty, CJ Benayoun, M Berdoz, A Beuchert, K Bischoff, S Blum, P Braune, K Bugg, DV Case, T Cramer, O Crede, V Crowe, KM Degener, T Djaoshvili, N von Dombrowski, S Doser, M Dunnweber, W Ehmanns, A Engelhardt, D Faessler, MA Giarritta, P Haddock, RP Heinsius, FH Heinzelmann, M Herbstrith, A Herz, M Hessey, NP Hidas, P Hodd, C Holtzhaussen, C Jamnik, D Kalinowsky, H Kammle, B Kammel, P Kisiel, J Klempt, E Koch, H Kolo, C Kunze, M Kurilla, U Lakata, M Landua, R Matthay, H McCrady, R Meier, J Meyer, CA Montanet, L Ouared, R Ould-Saada, F Peters, K Pick, B Pietra, C Pinder, CN Ratajczak, M Regenfus, C Resag, S Roethel, W Schmidt, P Scott, I Seibert, R Spanier, S Stock, H Strassburger, C Strohbusch, U Suffert, M Thoma, U Tischhauser, M Volcker, C Wallis, S Walther, D WIedner, U Wittmack, K Zou, BS CA Crystal Barrel Collaboration TI Momentum dependence of the decay eta ->pi(+)pi(-)pi(0) SO PHYSICS LETTERS B LA English DT Article ID ETA->3-PI AB The pi(0) momentum dependence of the decay eta --> pi(+)pi(-)pi(0) has been measured with the Crystal Barrel detector. The analysis is based on 3230 events. The results of this independent measurement are compared to new chiral perturbation theory calculations and previous measurements. (C) 1998 Elsevier Science B.V. C1 Univ Karlsruhe, D-76021 Karlsruhe, Germany. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. Ruhr Univ Bochum, D-44780 Bochum, Germany. Univ Bonn, D-53115 Bonn, Germany. Hungarian Acad Sci, H-1525 Budapest, Hungary. Rutherford Appleton Lab, Didcot OX11 0QX, Oxon, England. CERN, CH-1211 Geneva 4, Switzerland. RP Abele, A (reprint author), Univ Karlsruhe, D-76021 Karlsruhe, Germany. RI Meyer, Curtis/L-3488-2014 OI Meyer, Curtis/0000-0001-7599-3973 NR 11 TC 25 Z9 25 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 15 PY 1998 VL 417 IS 1-2 BP 197 EP 201 DI 10.1016/S0370-2693(97)01376-2 PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YY923 UT WOS:000072201500030 ER PT J AU Fontes, CJ AF Fontes, CJ TI The role of the 5p(5)5d configuration and spin-orbit coupling in the electron-impact excitation of the lowest-lying J=0 and J=2 levels of xenon and krypton SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID DIFFERENTIAL CROSS-SECTIONS; DISTORTED-WAVE CALCULATION; NOBLE-GASES; RARE-GASES; ARGON; XE AB Calculations of electron-impact differential cross sections (DCSs) for heavy rare gases have traditionally employed a single [np(5)(n + 1)s)] configuration to describe the lowest-lying excited levels. Such calculations have been applied to systems up through xenon (n = 5) with the assumption that additional configurations would give a negligible contribution to the DCS. While this assumption is certainly valid for neon and argon, Khakoo et al recently demonstrated the importance of including the 5p(5)5d configuration when calculating the DCSs of the lowest-lying J = 0 and J = 2 levels of xenon. In particular, their calculated ratios of these two DCSs agree better with experiment and exhibit a more radical departure from the expected 5:1 statistical value than predicted by earlier theoretical investigations. In this paper we show that the 5p(5)5d configuration in conjunction with the spin-orbit coupling effect is responsible for the different behaviour in the cross sections of the J = 0 and J = 2 levels. A similar, brief analysis is applied to the pair of lowest-lying J = 1 levels of xenon. The effect of the 4p(5)4d configuration on DCS calculations of krypton is also explored. C1 Univ Calif Los Alamos Natl Lab, Appl Theoret Div, Los Alamos, NM 87545 USA. RP Fontes, CJ (reprint author), Univ Calif Los Alamos Natl Lab, Appl Theoret Div, POB 1663, Los Alamos, NM 87545 USA. NR 12 TC 2 Z9 2 U1 2 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JAN 14 PY 1998 VL 31 IS 1 BP 175 EP 181 DI 10.1088/0953-4075/31/1/017 PG 7 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YV406 UT WOS:000071819800017 ER PT J AU Krstic, PS Schultz, DR Bent, G AF Krstic, PS Schultz, DR Bent, G TI Ionization of He by slow protons SO JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS LA English DT Article ID HARTREE-FOCK SCHEME; ELECTRON-CAPTURE; CROSS-SECTIONS; COLLISIONS; HELIUM; STATES; IONS; EXCITATION; IMPACT; ATOM AB The recently developed method of multi-electronic hidden crossings is used to describe the ionization of He by proton impact. Single ionization is satisfactorily described by taking into account only single excited configurations within a fully correlated, molecular structure configuration interaction calculation of the electronic eigensurfaces in the plane of complex internuclear distance. However, a significant role is played by doubly excited states in double ionization. Within this theoretical framework, the single-ionization mechanism is found and described by a series of hidden crossings. A comparison with measurements and other theoretical approaches is given. C1 Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. Univ Connecticut, Dept Phys, Storrs, CT 06269 USA. RP Oak Ridge Natl Lab, Div Phys, Oak Ridge, TN 37831 USA. NR 27 TC 4 Z9 4 U1 0 U2 3 PU IOP PUBLISHING LTD PI BRISTOL PA TEMPLE CIRCUS, TEMPLE WAY, BRISTOL BS1 6BE, ENGLAND SN 0953-4075 EI 1361-6455 J9 J PHYS B-AT MOL OPT JI J. Phys. B-At. Mol. Opt. Phys. PD JAN 14 PY 1998 VL 31 IS 1 BP 183 EP 195 DI 10.1088/0953-4075/31/1/018 PG 13 WC Optics; Physics, Atomic, Molecular & Chemical SC Optics; Physics GA YV406 UT WOS:000071819800018 ER PT J AU Christen, HM Norton, DP Gea, LA Boatner, LA AF Christen, HM Norton, DP Gea, LA Boatner, LA TI Pulsed laser deposition of solid-solution films using segmented targets SO THIN SOLID FILMS LA English DT Article DE pulsed laser; solid-solution films; laser beam ID KNBO3 THIN-FILMS; CHEMICAL-VAPOR-DEPOSITION; POTASSIUM NIOBATE; GROWTH; MGO AB A new method for the growth of solid-solution thin films has been developed in which a pre-determined ratio of the components can be deposited by the controlled use of a single rotating target. This variable compositional control is achieved by altering the radial position of either the target, which incorporates wedge-shaped segments of the solid-solution components, or of the laser beam. The method was used to grow films of the solid solution KTa1-xNbxO3 for which the predicted and measured values of the ferroelectric transition temperature far selected Ta/Nb ratios were in excellent agreement. This approach is generally applicable to solid-solution systems and is not restricted to ferroelectric oxides. (C) 1998 Elsevier Science S.A. C1 Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Christen, HM (reprint author), Neocera Inc, 10000 Virginia Manor Rd,Suite 300, Beltsville, MD 20705 USA. RI Christen, Hans/H-6551-2013; Boatner, Lynn/I-6428-2013 OI Christen, Hans/0000-0001-8187-7469; Boatner, Lynn/0000-0002-0235-7594 NR 20 TC 21 Z9 21 U1 0 U2 5 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 JAN 14 PY 1998 VL 312 IS 1-2 BP 156 EP 159 DI 10.1016/S0040-6090(97)00736-0 PG 4 WC Materials Science, Multidisciplinary; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter SC Materials Science; Physics GA ZN334 UT WOS:000073635500028 ER PT J AU Durston, PJ Palmer, RE Wilcoxon, JP AF Durston, PJ Palmer, RE Wilcoxon, JP TI Manipulation of passivated gold clusters on graphite with the scanning tunneling microscope SO APPLIED PHYSICS LETTERS LA English DT Article ID ATOMIC-FORCE MICROSCOPE; ARRAYS AB Chemically passivated gold nanoclusters deposited on the surface of graphite have been manipulated with the scanning tunneling microscope (STM) in ultrahigh vacuum. The controlled clearing of a definite shape in a cluster layer is demonstrated. Clusters embedded in a close-packed array could not be removed from the surface, apparently because of the attractive interaction between neighboring ligand chains. A minority channel of cluster fragmentation has been identified and leads to the creation of platelets which can be further manipulated by the STM tip. (C) 1998 American Institute of Physics. C1 Univ Birmingham, Sch Phys & Astron, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. Sandia Natl Labs, Nanstruct & Adv Mat Dept 1152, Albuquerque, NM 87185 USA. RP Durston, PJ (reprint author), Univ Birmingham, Sch Phys & Astron, Nanoscale Phys Res Lab, Birmingham B15 2TT, W Midlands, England. EM r.e.palmer@bham.ac.uk RI Palmer, Richard/A-5366-2008 OI Palmer, Richard/0000-0001-8728-8083 NR 15 TC 34 Z9 34 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 12 PY 1998 VL 72 IS 2 BP 176 EP 178 DI 10.1063/1.120677 PG 3 WC Physics, Applied SC Physics GA YQ549 UT WOS:000071398900015 ER PT J AU Ruvimov, S Dicker, C Washburn, J Liliental-Weber, Z AF Ruvimov, S Dicker, C Washburn, J Liliental-Weber, Z TI Twin formation in As precipitates in low-temperature GaAs during high-temperature annealing SO APPLIED PHYSICS LETTERS LA English DT Article ID MOLECULAR-BEAM EPITAXY; LAYERS AB High-resolution electron microscopy was employed to study the atomic structure of As precipitates formed in low-temperature GaAs during high-temperature annealing,most all the precipitates after annealing at 850 and 950 degrees C were found to be twinned with a {<(1)over bar 104>} crystallographic twin plane. Twinning is associated with the crystallization of amorphous or liquidlike As precipitates during cooling. Nucleation of rhombohedral As appears to be most favorable on the short facet that is parallel to the {111}B plane of GaAs. Twin formation usually initiates on the long facet bounded by the {111}A plane. The crystallization usually terminated with a void because of the shrinkage of the As volume during solidification. (C) 1998 American Institute of Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. EM ruv@mh1.lbl.gov RI Liliental-Weber, Zuzanna/H-8006-2012 NR 14 TC 8 Z9 8 U1 0 U2 2 PU AMER INST PHYSICS PI MELVILLE PA 1305 WALT WHITMAN RD, STE 300, MELVILLE, NY 11747-4501 USA SN 0003-6951 EI 1077-3118 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 12 PY 1998 VL 72 IS 2 BP 226 EP 228 DI 10.1063/1.120693 PG 3 WC Physics, Applied SC Physics GA YQ549 UT WOS:000071398900032 ER PT J AU Hirai, Y Lochter, A Galosy, S Koshida, S Niwa, S Bissell, MJ AF Hirai, Y Lochter, A Galosy, S Koshida, S Niwa, S Bissell, MJ TI Epimorphin functions as a key morphoregulator for mammary epithelial cells SO JOURNAL OF CELL BIOLOGY LA English DT Article ID HEPATOCYTE GROWTH-FACTOR; PRESYNAPTIC GLUTAMATE-RECEPTOR; DUCTAL MORPHOGENESIS; EXTRACELLULAR-MATRIX; GENE-EXPRESSION; TRANSGENIC MICE; CULTURED-CELLS; E-CADHERIN; GLAND; DIFFERENTIATION AB Hepatocyte growth factor (HGF) and EGF have been reported to promote branching morphogenesis of mammary epithelial cells, We now show that it is epimorphin that is primarily responsible for this phenomenon, In vivo, epimorphin was detected in the stromal compartment but not in lumenal epithelial cells of the mammary gland; in culture, however, a subpopulation of mammary epithelial cells produced significant amounts of epimorphin. When epimorphin-expressing epithelial cell clones were cultured in collagen gels they displayed branching morphogenesis in the presence of HGF, EGF, keratinocyte growth factor, or fibroblast growth factor, a process that was inhibited by anti-epimorphin but not anti-HGF antibodies. The branch length, however, was roughly proportional to the ability of the factors to induce growth, Accordingly, epimorphin-negative epithelial cells simply grew in a cluster in response to the growth factors and failed to branch. When recombinant epimorphin was added to these collagen gels, epimorphin-negative cells underwent branching morphogenesis. The mode of action of epimorphin on morphogenesis of the gland, however, was dependent on how it was presented to the mammary cells. If epimorphin was overexpressed in epimorphin-negative epithelial cells under regulation of an inducible promoter or was allowed to coat the surface of each epithelial cell in a nonpolar fashion, the cells formed globular, alveoli-like structures with a large central lumen instead of branching ducts, This process was enhanced also by addition of HGF, EGF, or other growth factors and was inhibited by epimorphin antibodies. These results suggest that epimorphin is the primary morphogen in the mammary gland but that growth factors are necessary to achieve the appropriate cell numbers for the resulting morphogenesis to be visualized. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. Sumitomo Elect Ind Ltd, Biomed Res & Dev Dept, Yokohama, Kanagawa 244, Japan. RP Hirai, Y (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd,MS 83-101, Berkeley, CA 94720 USA. FU NCI NIH HHS [CA57621, R01 CA057621] NR 49 TC 117 Z9 118 U1 1 U2 5 PU ROCKEFELLER UNIV PRESS PI NEW YORK PA 1114 FIRST AVE, 4TH FL, NEW YORK, NY 10021 USA SN 0021-9525 J9 J CELL BIOL JI J. Cell Biol. PD JAN 12 PY 1998 VL 140 IS 1 BP 159 EP 169 DI 10.1083/jcb.140.1.159 PG 11 WC Cell Biology SC Cell Biology GA YR491 UT WOS:000071500600016 PM 9425164 ER PT J AU Johnson, PD Chang, Y Brookes, NB Weinert, M AF Johnson, PD Chang, Y Brookes, NB Weinert, M TI Potassium adsorption and an unoccupied surface state on Fe(001) SO JOURNAL OF PHYSICS-CONDENSED MATTER LA English DT Article ID SPIN POLARIZATION ANALYZER; ELECTRONIC-STRUCTURE; PHOTOEMISSION; FE(100); SPECTROSCOPY AB Spin-polarized photoemission studies of potassium adsorption on an Fe(001) surface provide evidence of a minority-spin surface state sitting immediately above the Fermi level on the clean surface. This state of d(z)2 symmetry is associated with the surface state predicted in first-principles calculations and the state utilized in chemically selective scanning tunnelling microscopy studies of the Fe(001) surface. C1 Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. RP Johnson, PD (reprint author), Brookhaven Natl Lab, Dept Phys, Upton, NY 11973 USA. NR 14 TC 14 Z9 14 U1 0 U2 10 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0953-8984 J9 J PHYS-CONDENS MAT JI J. Phys.-Condes. Matter PD JAN 12 PY 1998 VL 10 IS 1 BP 95 EP 100 DI 10.1088/0953-8984/10/1/011 PG 6 WC Physics, Condensed Matter SC Physics GA YV398 UT WOS:000071819000011 ER PT J AU Chernikov, MA Ott, HR Bianchi, A Migliori, A Darling, TW AF Chernikov, MA Ott, HR Bianchi, A Migliori, A Darling, TW TI Elastic moduli of a single quasicrystal of decagonal Al-Ni-Co: Evidence for transverse elastic isotropy SO PHYSICAL REVIEW LETTERS LA English DT Article ID ICOSAHEDRAL QUASICRYSTALS; AL65CU20CO15; CRYSTALS AB The single quasicrystal elastic moduli c(ij) of decagonal Al-Ni-Co were determined using resonant ultrasound spectroscopy at selected fixed temperatures in the range between 5 and 290 K. Decagonal Al-Ni-Co is found to be transversely elastically isotropic to (0.02 +/- 0.04)%. The elastic moduli c(ij) (T) exhibit weak temperature dependences. The elastic Debye temperature Theta(D)(el) calculated from c(ij) measured at 5 K agrees well with the thermodynamic Debye temperature Theta(D)(th) obtained from a low-temperature specific-heat experiment. C1 ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Chernikov, MA (reprint author), ETH Honggerberg, Festkorperphys Lab, CH-8093 Zurich, Switzerland. RI Bianchi, Andrea/E-9779-2010 OI Bianchi, Andrea/0000-0001-9340-6971 NR 20 TC 78 Z9 83 U1 0 U2 7 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 12 PY 1998 VL 80 IS 2 BP 321 EP 324 DI 10.1103/PhysRevLett.80.321 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ975 UT WOS:000071444000029 ER PT J AU Ortiz, G Souza, I Martin, RM AF Ortiz, G Souza, I Martin, RM TI Exchange-correlation hole in polarized insulators: Implications for the microscopic functional theory of dielectrics SO PHYSICAL REVIEW LETTERS LA English DT Article ID MACROSCOPIC POLARIZATION; PHASE AB We present a simple and direct proof that the exchange-correlation hole, and therefore the exchange-correlation energy, in a polarized insulator is not determined by the bulk density alone. It is uniquely characterized by the density and the macroscopic electric polarization of the dielectric medium. C1 Univ Illinois, Dept Phys, Urbana, IL 61801 USA. Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA. Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Univ Illinois, Dept Phys, 1110 W Green St, Urbana, IL 61801 USA. NR 16 TC 25 Z9 25 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 12 PY 1998 VL 80 IS 2 BP 353 EP 356 DI 10.1103/PhysRevLett.80.353 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ975 UT WOS:000071444000037 ER PT J AU Li, SY Rodriguez, JA Hrbek, J Huang, HH Xu, GQ AF Li, SY Rodriguez, JA Hrbek, J Huang, HH Xu, GQ TI Chemical and electronic properties of silver atoms supported on sulfur and molybdenum sulfide surfaces SO SURFACE SCIENCE LA English DT Article DE ab initio quantum chemical methods and calculations; hydrogen; molybdenum; silver; sulfides; surface chemical reaction; thermal desorption spectroscopy; X-ray photoelectron spectroscopy ID HYDRODESULFURIZATION CATALYSTS; INTERMEDIATE NEGLECT; PROMOTED SULFIDATION; SINGLE-CRYSTAL; MOS2; ADSORPTION; HYDROGEN; RU(001); NI; COADSORPTION AB The chemical and electronic properties of a series of Ag/SmaltMo(110) and Ag/MoSX systems have been investigated using X-ray photoemission, thermal desorption mass spectroscopy, hydrogen (H-2, D-2, or D) chemisorption and molecular orbital calculations. At 100 K, sulfur multilayers supported on Mo(110) react with silver to form sulfide compounds. Upon annealing to high temperature, the silver sulfides promote the sulfidation of the Mo support leading to the formation MoSX. Silver atoms deposited on molybdenum sulfide surfaces remain in a metallic state at temperatures below 300 K. The results of INDO/S and ab initio self-consistent-field calculations indicate that the Ag-MoS2 bond is best described as covalent with a small degree of ionic character. On MoS2 surfaces, Ag is a poor electron donor compared with Co and Ni. At temperatures above 400 K 4g diffuses into the bulk of molybdenum sulfide. forming AgMoSX compounds. These bimetallic sulfides decompose at high temperatures (>800 K) with Ag desorbing and MoSX remaining solid. The AgSY/MoSX and ASMoS(X) systems were unreactive towards molecular hydrogen under ultrahigh vacuum conditions. However. gas-phase atomic hydrogen reacted with the surfaces to form gaseous hydrogen sulfide and led to sorption of hydrogen by the AgSY/MoSX and AgMoSX systems. Compared with other similar systems (MoSX, NiSY/MoSX, CoSY/MoSX, ZnSY/MoSX), the AgSY/MoSX systems show the lowest rate of hydrogenation of Mo-bonded S atoms. The Ag adatoms are very efficient for blocking D<->S interactions. (C) 1998 Elsevier Science B.V. C1 Natl Univ Singapore, Dept Chem, Singapore 119260, Singapore. Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RP Xu, GQ (reprint author), Natl Univ Singapore, Dept Chem, Singapore 119260, Singapore. EM chmxugq@nus.sg RI Xu, Guo Qin/C-2077-2013; Hrbek, Jan/I-1020-2013 NR 51 TC 15 Z9 16 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JAN 12 PY 1998 VL 395 IS 2-3 BP 216 EP 228 DI 10.1016/S0039-6028(97)00626-2 PG 13 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA YY858 UT WOS:000072194000014 ER PT J AU Kendelewicz, T Liu, P Brown, GE Nelson, EJ AF Kendelewicz, T Liu, P Brown, GE Nelson, EJ TI Atomic geometry of the PbS(100) surface SO SURFACE SCIENCE LA English DT Article DE photoelectron spectroscopy; surface relaxation; X-ray standing waves ID CORE-LEVEL SHIFTS; SYNCHROTRON RADIATION; CROSS-SECTION; 110 SURFACES; RELAXATION; SEMICONDUCTORS; OVERLAYERS; GALENA AB The surface structure of PbS(100), in the form of the mineral galena, was studied with the X-ray standing wave technique using surface-sensitive Auger electron yield detection and normal incidence geometry. We find that neither S nor Pb surface atoms are displaced from their respective bulk site positions. This lack of surface relaxation differs from the recent suggestion based on theory that a sizable contraction is needed to explain the experimentally observed lack of a surface core-level shift in Pb 5d photoemission data. To shed more light on this issue, we have also measured high-resolution Pb 4f, Pb 5d, and S 2p photoemission spectra for PbS(100) and confirmed that the surface core-level shifts are absent for cations as well as for anions. (C) 1998 Elsevier Science B.V. C1 Stanford Univ, Dept Geog & Environm Sci, Stanford, CA 94309 USA. Stanford Univ, SLAC, Stanford Synchrotron Radiat Lab, Stanford, CA 94305 USA. RP Kendelewicz, T (reprint author), Stanford Univ, Dept Geog & Environm Sci, Stanford, CA 94309 USA. NR 22 TC 20 Z9 20 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 JAN 12 PY 1998 VL 395 IS 2-3 BP 229 EP 238 DI 10.1016/S0039-6028(97)00627-4 PG 10 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA YY858 UT WOS:000072194000015 ER PT J AU Yoon, HA Salmeron, M Somorjai, GA AF Yoon, HA Salmeron, M Somorjai, GA TI An LEED and STM study of the structures formed by sulfur on the Rh(111) surface SO SURFACE SCIENCE LA English DT Article DE metal surface; rhodium; scanning tunneling microscopy; sulfur; surface structure ID SCANNING-TUNNELING-MICROSCOPY; 111 SURFACE; ELECTRON-DIFFRACTION; PD(111) SURFACE; ADSORPTION SITE; CRYSTALLOGRAPHY; RE(0001); RELAXATIONS; OVERLAYERS; PLATINUM AB The structures formed by sulfur adsorbed on the Rh(111) surface have been studied with Auger electron spectroscopy (AES), low-energy electron diffraction (LEED) and scanning tunneling microscopy (STM). Five differently ordered overlayer structures were observed to form as a function of coverage. These are: (root 3 x root 3)R30 degrees, c(root 3 x 7)rect, c(4 x 2), (4 x 4) and (7 x 7). The first structure forms up to 0.33 monolayers, with S occupying fee hollow sites. Above 0.33, hcp hollow sites are occupied as well. In the c(4 x 2) structure, at 0.5 monolayer coverage, there is equal occupation of fee and hcp hollow sites. The transition from the (root 3 x root 3)R30 degrees to c(4 x 2) overlayer occurs by formation of dense domain boundaries containing both fee and hcp sites. The S in the hcp sites is metastable and, upon heating, it moves to nearest fee sites to produce the (4 x 4) structure. (C) 1998 Elsevier Science B.V. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. RP Salmeron, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. EM salmeron@stm.lbl.gov NR 39 TC 17 Z9 17 U1 1 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 JAN 12 PY 1998 VL 395 IS 2-3 BP 268 EP 279 DI 10.1016/S0039-6028(97)00631-6 PG 12 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA YY858 UT WOS:000072194000019 ER PT J AU Tobin, JG Goodman, KW Schumann, FO Willis, RF Kortright, JB Denlinger, JD Rotenberg, E Warwick, A Smith, NV AF Tobin, JG Goodman, KW Schumann, FO Willis, RF Kortright, JB Denlinger, JD Rotenberg, E Warwick, A Smith, NV TI Direct extraction of exchange splittings from magnetic X-ray dichroism in photoelectron spectroscopy SO SURFACE SCIENCE LA English DT Letter DE alloys; angle resolved photoemission; iron; magnetic films; magnetic phenomena; magnetic surfaces; nickel; photoelectron spectroscopy; semi-empirical models and model calculations; soft X-ray photoelectron spectroscopy ID CORE-LEVEL PHOTOEMISSION; LINEARLY POLARIZED-LIGHT; 2P ABSORPTION-SPECTRA; CIRCULAR-DICHROISM; BRANCHING RATIO; 4F PHOTOEMISSION; ULTRATHIN FILMS; FINE-STRUCTURE; ALLOY-FILMS; FE AB It will be demonstrated that core-level exchange splitting can be extracted directly from normalized difference curves in magnetic X-ray circular dichroism (MXCD) in angle-resolved photoelectron spectroscopy (PES). Although high resolution is a requirement for the method, this determination can be performed without resorting to time-consuming and difficult spectral simulations. For well-defined cases, it will be shown empirically that this method may also work for the analysis of magnetic X-ray linear dichroism (MXLD). Applying this approach, it will be possible to use MXCD and MXLD in PES for direct surface magnetometry with full elemental specificity. (C) 1998 Elsevier Science B.V. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Penn State Univ, Dept Phys, University Pk, PA 16802 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Tobin, JG (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 East Ave, Livermore, CA 94550 USA. RI Rotenberg, Eli/B-3700-2009; Schumann, Frank /K-9364-2014; Tobin, James/O-6953-2015 OI Rotenberg, Eli/0000-0002-3979-8844; NR 41 TC 12 Z9 12 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0039-6028 J9 SURF SCI JI Surf. Sci. PD JAN 12 PY 1998 VL 395 IS 2-3 BP L227 EP L235 DI 10.1016/S0039-6028(97)00831-5 PG 9 WC Chemistry, Physical; Physics, Condensed Matter SC Chemistry; Physics GA YY858 UT WOS:000072194000002 ER PT J AU Romalis, MV Bogorad, PL Cates, GD Chupp, TE Coulter, KP Hughes, EW Johnson, JR Kumar, KS Smith, TB Thompson, AK Welsh, R AF Romalis, MV Bogorad, PL Cates, GD Chupp, TE Coulter, KP Hughes, EW Johnson, JR Kumar, KS Smith, TB Thompson, AK Welsh, R TI Toward precision polarimetry of dense polarized He-3 targets SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th RCNP International Workshop on Polarized 3He Beams and Gas Targets and Their Application (HELION 97) CY JAN 20-24, 1997 CL KOBE, JAPAN SP Osaka Univ, Res Ctr Nucl Phys, Phys Soc Japan, Kobe Tokiwa Coll, Konan Univ, Kobe City, Hyogo Prefecture, Mitsubishi Elect Co, Spectra Phys, Japan, Osaka Vacuum Co Ltd, Morishima Manufactory, Toei Works, Anzai Grp ID DEPENDENT FREQUENCY-SHIFTS; NUCLEAR-POLARIZATION; OPTICAL MEASUREMENT; RB-HE-3 COLLISIONS AB We describe several new measurement and analysis techniques used to determine the polarization of the He-3 target in a recently completed measurement of the neutron spin structure function g(1)(n) at SLAC (E-154). Tne polarization was determined using two independent methods. The first method used a standard technique of Adiabatic Fast Passage, calibrated by a measurement af Boltzmann polarization in a sample of water. We describe several systematic effects affecting this calibration procedure, The second method used a shift of the Rb Zeeman resonance frequency due to the polarization of He-3. Implementation and calibration of this technique are discussed in detail. Finally, the density of He-3 in the cell was measured using two independent methods, one of them based on the pressure broadening of Rb D-1 anti D-2 lines due to He-3. C1 Princeton Univ, Princeton, NJ 08544 USA. Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. Natl Inst Stand & Technol, Gainesville, MD 20899 USA. Univ Michigan, Ann Arbor, MI 48109 USA. CALTECH, Pasadena, CA 91125 USA. RP Romalis, MV (reprint author), Princeton Univ, Princeton, NJ 08544 USA. NR 20 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 1998 VL 402 IS 2-3 BP 260 EP 267 DI 10.1016/S0168-9002(97)00847-4 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU452 UT WOS:000071718800019 ER PT J AU van den Brand, JFJ Alarcon, R Bauer, T Boersma, D Botto, T Bulten, HJ van Buuren, L Ent, R Ferro-Luzzi, M Geurts, D Harvey, M Heimberg, P Highinbotham, D de Jager, CW Norum, B Passchier, I Poolman, HR van der Putte, M Six, E Steijger, J Szczerba, D de Vries, H AF van den Brand, JFJ Alarcon, R Bauer, T Boersma, D Botto, T Bulten, HJ van Buuren, L Ent, R Ferro-Luzzi, M Geurts, D Harvey, M Heimberg, P Highinbotham, D de Jager, CW Norum, B Passchier, I Poolman, HR van der Putte, M Six, E Steijger, J Szczerba, D de Vries, H TI Spin effects in medium-energy electron-He-3 scattering SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th RCNP International Workshop on Polarized 3He Beams and Gas Targets and Their Application (HELION 97) CY JAN 20-24, 1997 CL KOBE, JAPAN SP Osaka Univ, Res Ctr Nucl Phys, Phys Soc Japan, Kobe Tokiwa Coll, Konan Univ, Kobe City, Hyogo Prefecture, Mitsubishi Elect Co, Spectra Phys, Japan, Osaka Vacuum Co Ltd, Morishima Manufactory, Toei Works, Anzai Grp ID QUASI-ELASTIC SCATTERING; POLARIZED ELECTRONS; FORM-FACTOR; HE-3; NEUTRON; OBSERVABLES; MODEL AB New physics can be accessed by scattering polarized electrons from a polarized He-3 internal gas target. It is discussed how the asymmetries for the reactions <(He-3)over right arrow>((e) over right arrow, e'), <(He-3)over right arrow>((e) over right arrow, e'p) <(He-3)over right arrow>((e) over right arrow, e'n) <(He-3)over right arrow>((e) over right arrow, e'd) and <(He-3)over right arrow>((e) over right arrow, e'pn) may provide precise information on the S' and the D-wave parts of the He-3 ground-state wave function, the neutron form factors, and the role of spin-dependent reaction mechanism effects. The experiment uses up to 900 MeV (polarized) electrons from the AmPS storage ring in Amsterdam, Netherlands, in combination with large acceptance electron and hadron detectors. C1 Free Univ Amsterdam, Dept Phys & Astron, NL-1081 HV Amsterdam, Netherlands. NIKHEF H, NL-1009 DB Amsterdam, Netherlands. Arizona State Univ, Dept Phys, Tempe, AZ 85287 USA. Rijks Univ Utrecht, Dept Phys, Utrecht, Netherlands. Hampton Univ, Dept Phys, Hampton, VA 23668 USA. TJNAF, Newport News, VA 23606 USA. Univ Virginia, Dept Phys, Charlottesville, VA 22901 USA. RP van den Brand, JFJ (reprint author), Free Univ Amsterdam, Dept Phys & Astron, De Boelelaan 1081, NL-1081 HV Amsterdam, Netherlands. NR 17 TC 3 Z9 3 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 1998 VL 402 IS 2-3 BP 268 EP 276 DI 10.1016/S0168-9002(97)00848-6 PG 9 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU452 UT WOS:000071718800020 ER PT J AU Gao, H AF Gao, H TI Precise measurement of the neutron magnetic form factor from quasielastic (He-3)over-right-arrow((e)over-right-arrow, e ') SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th RCNP International Workshop on Polarized 3He Beams and Gas Targets and Their Application (HELION 97) CY JAN 20-24, 1997 CL KOBE, JAPAN SP Osaka Univ, Res Ctr Nucl Phys, Phys Soc Japan, Kobe Tokiwa Coll, Konan Univ, Kobe City, Hyogo Prefecture, Mitsubishi Elect Co, Spectra Phys, Japan, Osaka Vacuum Co Ltd, Morishima Manufactory, Toei Works, Anzai Grp ID QUASI-ELASTIC SCATTERING; DIODE-LASER ARRAYS; POLARIZED HE-3; ELECTRON-SCATTERING; SPIN EXCHANGE; NUCLEI; GAS; RB AB Polarized He-3 targets have proven to be a useful tool for studying the electric and magnetic form factors of the neutron, and the spin structure of the neutron. The neutron magnetic form factor at low Q(2) was previously determined at MIT-Bates from the quasielastic (3) (H) over right arrow e((e) over right arrow,e') process. A new experiment is planned at TJNAF to systematically measure the inclusive He-3 quasielastic transverse asymmetry, A(T'), at Q(2) = 0.1-0.5 (GeV/c)(2) with high statistical and systematic accuracy. A 2% statistical uncertainty is aimed at all the proposed values of Q(2), and 3% systematic uncertainty for A(T), can be achieved for this experiment. The precise data will constrain theoretical calculations of He-3 quasielastic asymmetry. Furthermore, the neutron magnetic form factor at Q(2) = 0.1-0.5 (Gev/c)(2) will be extracted from the measured asymmetries with an overall uncertainty of 2%. Precise measurements of G(M)(n) at low Q(2) will resolve the discrepancy among the existing data in the same Q(2) region. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Gao, H (reprint author), Argonne Natl Lab, Argonne, IL 60439 USA. RI Gao, Haiyan/G-2589-2011 NR 44 TC 5 Z9 5 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 1998 VL 402 IS 2-3 BP 277 EP 283 DI 10.1016/S0168-9002(97)00849-8 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU452 UT WOS:000071718800021 ER PT J AU Souder, PA Bogorad, PL Brash, EJ Cates, GD Cummings, WJ Gorelov, A Hasinoff, MD Hausser, O Hicks, K Holmes, R Huang, JC Kumar, KS Larson, B Lorenzon, W McCracken, J Michaux, P Middleton, H Saettler, E Siegel, D Tupa, D Wang, X Young, A AF Souder, PA Bogorad, PL Brash, EJ Cates, GD Cummings, WJ Gorelov, A Hasinoff, MD Hausser, O Hicks, K Holmes, R Huang, JC Kumar, KS Larson, B Lorenzon, W McCracken, J Michaux, P Middleton, H Saettler, E Siegel, D Tupa, D Wang, X Young, A TI Laser polarized muonic He-3 and spin dependent mu(-) capture SO NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT LA English DT Article; Proceedings Paper CT 7th RCNP International Workshop on Polarized 3He Beams and Gas Targets and Their Application (HELION 97) CY JAN 20-24, 1997 CL KOBE, JAPAN SP Osaka Univ, Res Ctr Nucl Phys, Phys Soc Japan, Kobe Tokiwa Coll, Konan Univ, Kobe City, Hyogo Prefecture, Mitsubishi Elect Co, Spectra Phys, Japan, Osaka Vacuum Co Ltd, Morishima Manufactory, Toei Works, Anzai Grp DE muon; pseudoscalar; polarized target ID PSEUDOSCALAR COUPLING-CONSTANT; HELIUM ATOM; MU; RB AB We have developed an apparatus that can polarize muonic He-3 and detect the triton from the reaction mu(-) and He-3 --> nu + H-3. With this apparatus, we have measured the vector analyzing power of the reaction. This technique promises to provide a good test of QCD. C1 Syracuse Univ, Syracuse, NY 13214 USA. Princeton Univ, Princeton, NJ 08544 USA. Simon Fraser Univ, Burnaby, BC V5A 1S6, Canada. Univ British Columbia, Vancouver, BC V6T 1Z1, Canada. TRIUMF, Vancouver, BC V6T 2A3, Canada. Ohio Univ, Athens, OH 45701 USA. Univ Penn, Philadelphia, PA 19104 USA. Los Alamos Natl Lab, Los Alamos, NM USA. RP Souder, PA (reprint author), Syracuse Univ, Syracuse, NY 13214 USA. NR 21 TC 13 Z9 13 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0168-9002 J9 NUCL INSTRUM METH A JI Nucl. Instrum. Methods Phys. Res. Sect. A-Accel. Spectrom. Dect. Assoc. Equip. PD JAN 11 PY 1998 VL 402 IS 2-3 BP 311 EP 318 DI 10.1016/S0168-9002(97)00855-3 PG 8 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Physics, Particles & Fields SC Instruments & Instrumentation; Nuclear Science & Technology; Physics GA YU452 UT WOS:000071718800027 ER PT J AU Stanford, SA Eisenhardt, PR Dickson, M AF Stanford, SA Eisenhardt, PR Dickson, M TI The evolution of early-type galaxies in distant clusters SO ASTROPHYSICAL JOURNAL LA English DT Article DE galaxies, clusters, general; galaxies, elliptical and lenticular, cD; galaxies, evolution; galaxies, photometry ID ELLIPTICAL GALAXIES; STAR-FORMATION; STELLAR POPULATIONS; MAGNITUDE RELATION; DISK GALAXIES; COLORS; PHOTOMETRY; MODEL; COMA; HST AB We present results from an optical-infrared photometric study of early-type (E+S0) galaxies in 19 galaxy clusters out to z = 0.9. The galaxy sample is selected on the basis of morphologies determined from Hubble Space Telescope (HST) WFPC2 images and is photometrically defined in the K band in order to minimize redshift-dependent selection biases. Using new ground-based photometry in five optical and infrared bands for each cluster, we examine the evolution of the color-magnitude relation for early-type cluster galaxies, considering its slope, intercept, and color scatter around the mean relation. New multiwavelength photometry of galaxies in the Coma Cluster is used to provide a baseline sample at z approximate to 0 with which to compare the distant clusters. The optical-IR colors of the early-type cluster galaxies become bluer with increasing redshift in a manner consistent with the passive evolution of an old stellar population formed at an early cosmic epoch. The degree of color evolution is similar for clusters at similar redshift and does not depend strongly on the optical richness or X-ray luminosity of the cluster, which suggests that the history of early-type galaxies is relatively insensitive to environment, at least above a certain density threshold. The slope of the color-magnitude relationship shows no significant change out to z = 0.9, which provides evidence that it arises from a correlation between galaxy mass and metallicity, not age. Finally, the intrinsic scatter in the optical-IR colors of the galaxies is small and nearly constant with redshift, which indicates that the majority of giant, early-type galaxies in clusters share a common star formation history, with little perturbation due to uncorrelated episodes of later star formation. Taken together, our results are consistent with models in which most early-type galaxies in rich clusters are old, formed the majority of their stars at high redshift in a well-synchronized fashion, and evolved quiescently thereafter. We consider several possible effects that may be introduced by the choice of morphologically recognizable elliptical and SO galaxies in dense environments as a subject for study. In particular, the inclusion of SO galaxies, which might be undergoing morphological transformation in clusters as part of the Butcher-Oemler effect, may influence the results of our investigation. C1 CALTECH, Jet Prop Lab, Pasadena, CA 91109 USA. Lawrence Livermore Natl Lab, Inst Geophys & Planetary Phys, Livermore, CA 94550 USA. Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA. Johns Hopkins Univ, Space Telescope Sci Inst, Baltimore, MD 21218 USA. RP Dickson, M (reprint author), CALTECH, Jet Prop Lab, 4800 Oak Grove Dr, Pasadena, CA 91109 USA. NR 72 TC 465 Z9 465 U1 0 U2 0 PU IOP PUBLISHING LTD PI BRISTOL PA DIRAC HOUSE, TEMPLE BACK, BRISTOL BS1 6BE, ENGLAND SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1998 VL 492 IS 2 BP 461 EP 479 DI 10.1086/305050 PN 1 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YU308 UT WOS:000071704200005 ER PT J AU Richer, J Michaud, G Rogers, F Iglesias, C Turcotte, S LeBlanc, F AF Richer, J Michaud, G Rogers, F Iglesias, C Turcotte, S LeBlanc, F TI Radiative accelerations for evolutionary model calculations SO ASTROPHYSICAL JOURNAL LA English DT Article DE atomic data; diffusion; stars, interiors ID STELLAR ENVELOPES; MOMENTUM-TRANSFER; STARS; OPACITIES; PHOTOIONIZATION; DIFFUSION; FORCES; ANOMALIES; CARBON; OXYGEN AB Monochromatic opacities from the OPAL database have been used to calculate radiative accelerations for the 21 included chemical species. The 10(4) frequencies used are sufficient to calculate the radiative accelerations of many elements for T > 10(5) K, using frequency sampling. This temperature limit is higher for less abundant elements. As the abundances of Fe, He, or O are varied, the radiative acceleration of other elements changes, since abundant elements modify the frequency dependence of the radiative flux and the Rosseland opacity. Accurate radiative accelerations for a given element can only be obtained by allowing the abundances of the species that contribute most to the Rosseland opacity to vary during the evolution and recalculating the radiative accelerations and the Rosseland opacity during the evolution. There are physical phenomena that cannot be included in the calculations if one uses only the OPAL data. For instance, one should correct for the momentum given to the electron in a photoionization. Such effects are evaluated using atomic data from Opacity Project, and correction factors are given. C1 Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Univ Montreal, Dept Phys, Montreal, PQ H3C 3J7, Canada. Univ Moncton, Dept Phys, Moncton, NB E1A 3E9, Canada. RP Richer, J (reprint author), CERCA, 5160 Blvd Decarie, Montreal, PQ H3X 2H9, Canada. NR 31 TC 73 Z9 73 U1 0 U2 0 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1998 VL 492 IS 2 BP 833 EP 842 DI 10.1086/305054 PN 1 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YU308 UT WOS:000071704200033 ER PT J AU Wishnow, EH Ozier, I Gush, HP Schaefer, J AF Wishnow, EH Ozier, I Gush, HP Schaefer, J TI Translational band of gaseous hydrogen at low temperature SO ASTROPHYSICAL JOURNAL LA English DT Article DE infrared, general; methods, laboratory; methods, numerical; molecular processes ID GALAXIES COLD GAS; ABSORPTION-SPECTRA; INFRARED OBSERVATIONS; DARK-MATTER; H-2-H-2; FEATURES; SYSTEM; DIMERS; PAIRS AB A comparison is made between the observed submillimeter absorption spectrum of normal hydrogen gas at three different temperatures near 25 K and a fully quantum mechanical ab initio calculated spectrum. Measurements cover the wavenumber range 20-320 cm(-1), where, under the experimental conditions of low temperature and low pressure, the pure translational band is observed virtually isolated from the S(0) rotational line. The theoretical analysis shows that the H-2 spectrum is primarily due to transient collision-induced dipole moments in pairs of colliding molecules, i.e., due to free-free transitions. Bound-free transitions of the H-2 dimer are responsible for an additional similar to 10% of the absorption intensity. The agreement between the theoretical spectra and the measurements is excellent, thereby verifying that the intermolecular potential, the wave functions, and the model of the induced dipole moment have all been accurately represented. As a consequence, it is possible to predict with confidence the absorption spectrum of H-2 in physical conditions not readily accessible to laboratory measurements. C1 Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada. Univ Calif Lawrence Livermore Natl Lab, Astrophys Grp, Div 5, Livermore, CA 94551 USA. Max Planck Inst Astrophys, D-85740 Garching, Germany. RP Wishnow, EH (reprint author), Univ British Columbia, Dept Phys & Astron, 2036 Main Mall, Vancouver, BC V6T 1Z1, Canada. EM wishnow@llnl.gov; jas@mpa-garching.mpg.de NR 31 TC 4 Z9 4 U1 0 U2 1 PU UNIV CHICAGO PRESS PI CHICAGO PA 5801 S ELLIS AVENUE, CHICAGO, IL 60637 USA SN 0004-637X J9 ASTROPHYS J JI Astrophys. J. PD JAN 10 PY 1998 VL 492 IS 2 BP 843 EP 848 DI 10.1086/305060 PN 1 PG 6 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA YU308 UT WOS:000071704200034 ER PT J AU Borisov, L Halpern, MB Schweigert, C AF Borisov, L Halpern, MB Schweigert, C TI Systematic approach to cyclic orbifolds SO INTERNATIONAL JOURNAL OF MODERN PHYSICS A LA English DT Article ID CONFORMAL FIELD-THEORY; KAC-MOODY ALGEBRAS; PION-QUARK MODEL; VIRASORO ALGEBRAS; FREE FERMIONS; 2 DIMENSIONS; FIXED-POINTS; CONSTRUCTION; STRINGS; TENSOR AB We introduce an orbifold induction procedure which provides a systematic construction of cyclic orbifolds, including their twisted sectors. The procedure gives counterparts in the orbifold theory of all the current-algebraic constructions of conformal field theory and enables us to find the orbifold characters and their modular transformation properties. C1 Math Sci Res Inst, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RP Borisov, L (reprint author), Math Sci Res Inst, 1000 Centennial Dr, Berkeley, CA 94720 USA. OI Schweigert, Christoph/0000-0003-1342-6230 NR 61 TC 91 Z9 91 U1 1 U2 2 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA JOURNAL DEPT PO BOX 128 FARRER ROAD, SINGAPORE 9128, SINGAPORE SN 0217-751X J9 INT J MOD PHYS A JI Int. J. Mod. Phys. A PD JAN 10 PY 1998 VL 13 IS 1 BP 125 EP 168 DI 10.1142/S0217751X98000044 PG 44 WC Physics, Nuclear; Physics, Particles & Fields SC Physics GA YV595 UT WOS:000071842400003 ER PT J AU Goldman, T Maltman, K Stephenson, GJ Ping, JL Wang, F AF Goldman, T Maltman, K Stephenson, GJ Ping, JL Wang, F TI Systematic theoretical search for dibaryons in a relativistic model SO MODERN PHYSICS LETTERS A LA English DT Article ID INTERMEDIATE RANGE ATTRACTION; QUARK DELOCALIZATION; SUBSTRUCTURE AB A relativistic quark potential model is used to do a systematic search for quasi-stable dibaryon states in the u, d and s three-flavor world. Flavor symmetry breaking and channel coupling effects are included and an adiabatic method and fractional parentage expansion technique are used in the calculations. The relativistic model predicts dibaryon candidates completely consistent with the nonrelativistic model. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. York Univ, Dept Math & Stat, N York, ON M3J 1P3, Canada. Univ New Mexico, Dept Phys, Albuquerque, NM 87131 USA. Nanjing Normal Univ, Dept Phys, Nanjing 210097, Peoples R China. Nanjing Univ, Dept Phys, Nanjing 210008, Peoples R China. Nanjing Univ, Ctr Theoret Phys, Nanjing 210008, Peoples R China. RP Goldman, T (reprint author), Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 24 TC 43 Z9 43 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA 5 TOH TUCK LINK, SINGAPORE 596224, SINGAPORE SN 0217-7323 EI 1793-6632 J9 MOD PHYS LETT A JI Mod. Phys. Lett. A PD JAN 10 PY 1998 VL 13 IS 1 BP 59 EP 70 DI 10.1142/S0217732398000097 PG 12 WC Physics, Nuclear; Physics, Particles & Fields; Physics, Mathematical SC Physics GA YW432 UT WOS:000071934700008 ER PT J AU Loehle, C AF Loehle, C TI Superstars need not apply SO NEW SCIENTIST LA English DT Editorial Material C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Loehle, C (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU NEW SCIENTIST PUBL EXPEDITING INC PI ELMONT PA 200 MEACHAM AVE, ELMONT, NY 11003 USA SN 0262-4079 J9 NEW SCI JI New Sci. PD JAN 10 PY 1998 VL 157 IS 2116 BP 46 EP 46 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YR805 UT WOS:000071532000032 ER PT J AU Holesinger, TG Willis, JO Martinez, MC Coulter, JY AF Holesinger, TG Willis, JO Martinez, MC Coulter, JY TI Texture development in Bi2Sr2CaCu2Oy current leads SO PHYSICA C LA English DT Article DE superconductor; Bi-2212; isothermal; melt processing ID TAPES; SUPERCONDUCTORS; ANISOTROPY; FILMS AB Isothermal melt processing has been used to partially texture bulk samples of Bi2Sr2CaCu2Oy (Bi-2212). Anisotropic growth of Bi-2212 occurs from the partial melt in the presence of an oxygen gradient. The orientational preference is for the c-axis of the Bi-2212 grains to align perpendicular to the oxygen gradient. However, the one-dimensional nature of the oxygen gradient does not result in uniaxial texture. Incorporation of a set of silver plates aligned parallel to the oxygen gradient was found to provide the second texturing mechanism needed to improve grain-to-grain alignment and start the development of uniaxial texture within bulk Bi-2212 bars. Texture within the bars was investigated by anisotropy measurements of the critical current in applied magnetic fields and compared to previously published results on Bi-2212 films. At liquid nitrogen temperatures, the presence of partial texture in the bulk Bi-2212 bars was found to increase the performance in applied fields by a factor of two relative to the untextured current leads. However, comparison of the bulk-textured bar to the Bi-2212 film revealed that the bar has a significantly larger spread in grain orientations than does the 50 mu m thick film. (C) 1998 Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. RP Holesinger, TG (reprint author), Univ Calif Los Alamos Natl Lab, Superconduct Technol Ctr, Los Alamos, NM 87545 USA. NR 16 TC 2 Z9 2 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JAN 10 PY 1998 VL 294 IS 3-4 BP 161 EP 168 DI 10.1016/S0921-4534(97)01780-2 PG 8 WC Physics, Applied SC Physics GA ZC806 UT WOS:000072619900001 ER PT J AU Browning, ND Buban, JP Nellist, PD Norton, DP Chisholm, MF Pennycook, SJ AF Browning, ND Buban, JP Nellist, PD Norton, DP Chisholm, MF Pennycook, SJ TI The atomic origins of reduced critical currents at [001] tilt grain boundaries in YBa2Cu3O7-delta thin films SO PHYSICA C LA English DT Article DE grain boundaries; transport properties; EELS; Z-contrast; STEM ID TRANSPORT-PROPERTIES; PAIRING STATE; MICROSTRUCTURE; SYMMETRY; CRYSTALS; SRTIO3; SUPERCONDUCTORS; BICRYSTALS; INTERFACES AB Grain boundaries have long been known to have a deleterious and irreproducible effect on the transport properties of high-T-c oxide superconductors, particularly in the high-angle regime where an exponential decrease in critical current has been reported. We demonstrate, through a combination of atomic resolution Z-contrast imaging and bond valence sum analysis, that it is the atomic structure of the grain boundary that dominates this behavior. [001] tilt grain boundaries in thin-film YBa2Cu3O7-delta are composed of arrays of dislocations in defined sequences, The resulting strain fields seriously perturb the local electronic structure, leading to a non-superconducting zone at the grain boundary. The width of this zone increases linearly with misorientation angle, naturally explaining the observed exponential decrease in critical current. In addition, the widely varying J(c) measurements for a given grain boundary misorientation can be naturally explained by the facetting of the grain boundary plane. (C) 1998 Elsevier Science B.V. C1 Univ Illinois, Dept Phys MC 273, Chicago, IL 60607 USA. Oak Ridge Natl Lab, Div Solid State, Oak Ridge, TN 37831 USA. RP Browning, ND (reprint author), Univ Illinois, Dept Phys MC 273, 845 W Taylor St, Chicago, IL 60607 USA. EM browning@uic.edu OI Browning, Nigel/0000-0003-0491-251X NR 37 TC 118 Z9 119 U1 1 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JAN 10 PY 1998 VL 294 IS 3-4 BP 183 EP 193 DI 10.1016/S0921-4534(97)01689-4 PG 11 WC Physics, Applied SC Physics GA ZC806 UT WOS:000072619900004 ER PT J AU Xu, YW Wurnig, J Kramer, MJ Dennis, KW McCallum, RW Schwichtenberg, CR Moodenbaugh, AR AF Xu, YW Wurnig, J Kramer, MJ Dennis, KW McCallum, RW Schwichtenberg, CR Moodenbaugh, AR TI Superconductivity in reduced and then reoxidized Nd1.05Ba1.59(Cu1-xFex)(3)O7-delta SO PHYSICA C LA English DT Article DE substitution effects; structure; EELS ID NEUTRON-DIFFRACTION; ND; EU; DISORDER; CU; ER; DY; GD; YBA2(CU1-XFEX)3O7-DELTA; YBA2CU3O7-DELTA AB The system Nd1.05Ba1.95(Cu1-xFex)(3)O7-delta (NdFe-123) was studied. Substitution of Fe for Cu suppresses superconducting transition temperature T-c more rapidly in the NdFe-123 system than in the comparable YBa2(Cu1-xFex) (YFe-123) system. Samples reduced in argon and then reoxidized in oxygen at 400 degrees C show considerable increases in T-c. However, the T-c of these reoxidized samples still fall below those of similar YFe-123, Microstructural investigation by electron microscopy, structure from X-ray diffraction and their relationships to superconductivity are developed. Possible mechanisms for the T-c variations are discussed. (C) 1998 Elsevier Science B.V. C1 Mankato State Univ, Dept Phys & Astron, Mankato, MN 56002 USA. S Dakota Sch Mines & Tech, Dept Phys, Rapid City, SD 57702 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Brookhaven Natl Lab, Div Mat Sci, Upton, NY 11973 USA. RP Xu, YW (reprint author), Mankato State Univ, Dept Phys & Astron, Mankato, MN 56002 USA. OI Moodenbaugh, Arnold/0000-0002-3415-6762 NR 28 TC 2 Z9 2 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0921-4534 J9 PHYSICA C JI Physica C PD JAN 10 PY 1998 VL 294 IS 3-4 BP 194 EP 202 DI 10.1016/S0921-4534(97)01781-4 PG 9 WC Physics, Applied SC Physics GA ZC806 UT WOS:000072619900005 ER PT J AU Rouy, D Duverger, N Lin, SD Emmanuel, F Houdebine, LM Denefle, P Viglietta, C Gong, E Rubin, EM Hughes, SD AF Rouy, D Duverger, N Lin, SD Emmanuel, F Houdebine, LM Denefle, P Viglietta, C Gong, E Rubin, EM Hughes, SD TI Apolipoprotein(a) yeast artificial chromosome transgenic rabbits - Lipoprotein(a) assembly with human and rabbit apolipoprotein B SO JOURNAL OF BIOLOGICAL CHEMISTRY LA English DT Article ID EXPRESSING HUMAN APOLIPOPROTEIN(A); MICE; GENE; MUTAGENESIS; SITE AB The in vivo analysis of lipoprotein(a) (Lp(a)), an independent atherosclerosis risk factor in humans, has been limited in part by its restricted distribution among mammals, Although transgenic mice have been created containing Lp(a), the relatively small size of the mouse has precluded some studies. To examine the properties of this molecule in a significantly larger mammal, we have used a 270-kilobase yeast artificial chromosome clone containing the human apolipoprotein(a) (apo(a)) gene and a 90-kilobase P1 phagemid clone containing the human apolipoprotein B (apoB) gene to create transgenic rabbits that express either or both transgenes, Expression of both transgenes was tissue specific and localized predominantly to the liver, Average apolipoprotein plasma levels in the rabbits were 2.5 mg/dl for apo(a) and 17.6 mg/dl for human apoB. In contrast to observations in apo(a) transgenic mice, we found that apo(a) plasma levels in the rabbits were stable throughout sexual maturity, Also, apo(a) formed a covalent association with the endogenous rabbit apoB albeit with a lower efficiency than its association with human apoB, The analysis of Lp(a) transgenic rabbits has provided new insights into apo(a) expression and Lp(a) assembly, In addition, these transgenic rabbits potential will provide an improved experimental model for the in vivo analysis of Lp(a) and its role in promoting atherosclerosis and restenosis. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Human Genome, Div Life Sci, Berkeley, CA 94720 USA. Ctr Rech Vitry Alfortville, Rhone Poulenc Rorer Gencell, Atherosclerosis Dept, F-94403 Vitry Sur Seine, France. INRA, F-78352 Jouy En Josas, France. RP Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Human Genome, Div Life Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. EM emrubin@lbl.gov FU NHLBI NIH HHS [PPG HL18574] NR 21 TC 36 Z9 39 U1 0 U2 2 PU AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC PI BETHESDA PA 9650 ROCKVILLE PIKE, BETHESDA, MD 20814-3996 USA SN 0021-9258 EI 1083-351X J9 J BIOL CHEM JI J. Biol. Chem. PD JAN 9 PY 1998 VL 273 IS 2 BP 1247 EP 1251 DI 10.1074/jbc.273.2.1247 PG 5 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YQ669 UT WOS:000071411400082 PM 9422793 ER PT J AU Ting, EY Porter, MD AF Ting, EY Porter, MD TI Separations of benzodiazepines using electrochemically modulated liquid chromatography - Efficient separations from changes in the voltage applied to a porous graphitic carbon stationary phase SO JOURNAL OF CHROMATOGRAPHY A LA English DT Article DE stationary phases, LC; electrochemically modulated liquid chromatography; benzodiazepines ID POLYPYRROLE; EMLC AB Electrochemically modulated liquid chromatography has been applied to the separation of a mixture of benzodiazepines using a porous graphitic carbon (PGC) stationary phase. Changes in the voltage applied (E-appl) to PGC strongly alter the retention of all of the components in the mixture, having the unusual effect of stretching both ends of the chromatogram as E-appl becomes more negative. That is, the retention for some of the benzodiazepines increases as E-appl moves negatively, whereas that for some of the benzodiazepines decreases. Together, these dependencies result in the ability to resolve fully the mixture while only marginally increasing the total elution time with respect to that obtained at the open circuit potential. (C) 1998 Elsevier Science B.V. C1 US DOE, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Chem, Ames, IA 50011 USA. RP Porter, MD (reprint author), US DOE, Ames Lab, Microanalyt Instrumentat Ctr, Ames, IA 50011 USA. NR 18 TC 21 Z9 21 U1 1 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0021-9673 J9 J CHROMATOGR A JI J. Chromatogr. A PD JAN 9 PY 1998 VL 793 IS 1 BP 204 EP 208 DI 10.1016/S0021-9673(97)00855-8 PG 5 WC Biochemical Research Methods; Chemistry, Analytical SC Biochemistry & Molecular Biology; Chemistry GA YT992 UT WOS:000071668700021 ER PT J AU Krespan, CG Dixon, DA AF Krespan, CG Dixon, DA TI Transformations of F-alkyl iodides and bromides induced by nickel(0) carbonyl SO JOURNAL OF ORGANIC CHEMISTRY LA English DT Article ID ELECTRONIC-PROPERTIES; ENERGETICS; CONDENSATION; PALLADIUM; COMPLEXES AB Adducts of primary F-alkyl iodides with nickel carbonyl are formed readily in donor solvents and pyrolyze at 100-150 degrees C to give olefinic coupling products in high yield. The mechanism proposed to account for the observed chemistry involves preferential alpha-elimination of fluorine with formation of a carbenoid species complex coordinated to nickel. Differences in reaction paths among several types of substrate halides are rationalized on the basis of polarization of the Ni-C bond in the adducts, Support for these proposals is provided by state-of-the-art calculations. C1 DuPont Co Inc, Cent Res & Dev, Expt Stn, Wilmington, DE 19880 USA. Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Krespan, CG (reprint author), DuPont Co Inc, Cent Res & Dev, Expt Stn, POB 80328, Wilmington, DE 19880 USA. NR 32 TC 6 Z9 6 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0022-3263 J9 J ORG CHEM JI J. Org. Chem. PD JAN 9 PY 1998 VL 63 IS 1 BP 36 EP 43 DI 10.1021/jo970805y PG 8 WC Chemistry, Organic SC Chemistry GA YR487 UT WOS:000071500200008 ER PT J AU Ge, NH Wong, CM Lingle, RL McNeill, JD Gaffney, KJ Harris, CB AF Ge, NH Wong, CM Lingle, RL McNeill, JD Gaffney, KJ Harris, CB TI Femtosecond dynamics of electron localization at interfaces SO SCIENCE LA English DT Article ID 2-PHOTON PHOTOEMISSION; POLARONS; CRYSTALS AB The dynamics of two-dimensional smalt-polaron formation at ultrathin alkane layers on a silver(111) surface have been studied with femtosecond time-and angle-resolved two-photon photoemission spectroscopy. Optical excitation creates interfacial electrons in quasi-free states fbr motion parallel to the interface, These initially delocalized electrons self-trap as small polarons in a localized state within a few hundred femtoseconds. The localized electrons then decay back to the metal within picoseconds by tunneling through the adlayer potential barrier, The energy dependence of the self-trapping rate has been measured and modeled with a theory analogous to electron transfer theory. This analysis determines the inter-and intramolecular vibrational modes of the overlayer responsible for self-trapping as well as the relaxation energy of the overlayer molecular lattice. These results for a model interface contribute to the fundamental picture of electron behavior in weakly bonded solids and can lead to better understanding of carrier dynamics in many different systems, including organic light-emitting diodes. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Harris, CB (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM harris@socrates.berkeley.edu RI McNeill, Jason/E-5389-2011 NR 33 TC 180 Z9 180 U1 3 U2 34 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 USA SN 0036-8075 J9 SCIENCE JI Science PD JAN 9 PY 1998 VL 279 IS 5348 BP 202 EP 205 DI 10.1126/science.279.5348.202 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YQ636 UT WOS:000071408100034 ER PT J AU Batista, VS Miller, WH AF Batista, VS Miller, WH TI Semiclassical molecular dynamics simulations of ultrafast photodissociation dynamics associated with the Chappuis band of ozone SO JOURNAL OF CHEMICAL PHYSICS LA English DT Review ID CONSISTENT FIELD APPROXIMATION; POTENTIAL-ENERGY SURFACES; DEPENDENT ROTATED HARTREE; FEYNMAN PATH INTEGRATION; CURVE-CROSSING SYSTEM; INITIAL-VALUE METHOD; CLASSICAL ANALOG; WAVE-FUNCTIONS; PHASE-SPACE; REAL-TIME AB In this paper we investigate the nonadiabatic ultrafast dynamics of interconversion between the two lower lying excited states of (1)A " symmetry (1 (1)A " and 2 (1)A ") of ozone following photoexcitation of the molecule in the gas phase with visible light. Our algorithm involves a semiclassical initial value representation method which is able to describe electronically nonadiabatic processes within the time dependent picture through the quantization of the classical electron-nuclear model Hamiltonian of Meyer and Miller [J. Chem, Phys. 70, 7 (1979)]. We explore the capabilities of these techniques as applied to studying the dynamics of a realistic reaction of photodissociation on full nb initio electronic potential energy surfaces. Our semiclassical results provide an intuitive understanding of the most fundamental dynamical features involved in the process of predissociation, such as decay and recurrence events, as well as an interpretation of experimental studies of the Chappuis band of ozone in the frequency domain. (C) 1998 American Institute Physics. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Miller, WH (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Dept Chem, Berkeley, CA 94720 USA. EM miller@neon.cchem.berkely.edu NR 101 TC 65 Z9 65 U1 2 U2 9 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 JAN 8 PY 1998 VL 108 IS 2 BP 498 EP 510 DI 10.1063/1.475413 PG 13 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP022 UT WOS:000071233400016 ER PT J AU Curtiss, LA Raghavachari, K Redfern, PC Stefanov, BB AF Curtiss, LA Raghavachari, K Redfern, PC Stefanov, BB TI Assessment of complete basis set methods for calculation of enthalpies of formation SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID GAUSSIAN-2 THEORY; MODEL CHEMISTRY; G2 AB Three complete basis set models of Petersson cr nl. [J. Chem. Phys. 104, 2598 (1996)], CBS-QI CBS-q, and CBS-4, have been assessed on the G2 neutral test set of 148 molecules [J. Chem. Phys, 106, 1063 (1997)]. The average absolute deviations with experiment of the calculated enthalpies of formation from the three CBS methods are 1.57 kcal/mol (CBS-Q), 2.13 kcal/mol (CBS-q), and 3.06 kcal/mol (CBS-4). The maximum deviations of the methods are 11.2, 10.3, and 14.4 kcal/mol. respectively. The most accurate method, CBS-Q, has an average absolute deviation similar to that of G2 theory. The three CBS methods have also been assessed on a 40 molecule set using isodesmic bond separation reactions to calculate enthalpies of formation. There is a significant improvement in the accuracy of the enthalpies compared to these calculated using atomization energies? although not as much as for G2 theory. Ln a test on naphthalene, enthalpies calculated using the CBS methods have large deviations. The CBS-Q method has a deviation of 28.7 kcal/mol and, surprisingly, the deviation increases to 34.3 kcal/mol when isodesmic bond separation reaction energies are used. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Chem Technol, Argonne, IL 60439 USA. Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA. RP Curtiss, LA (reprint author), Argonne Natl Lab, Div Chem Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. RI Stefanov, Boris/E-8905-2012 NR 18 TC 83 Z9 84 U1 0 U2 10 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 1998 VL 108 IS 2 BP 692 EP 697 DI 10.1063/1.475442 PG 6 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP022 UT WOS:000071233400035 ER PT J AU Tammaro, M Evans, JW AF Tammaro, M Evans, JW TI Chemical diffusivity and wave propagation in surface reactions: Lattice-gas model mimicking CO-oxidation with high CO-mobility SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID KINETIC PHASE-TRANSITIONS; A-B(2) REACTION MODEL; MONTE-CARLO; SPANNING PROBABILITY; CATALYTIC REACTION; 2D PERCOLATION; BISTABILITY; SIMULATIONS; DESORPTION AB We analyze the spatiotemporal behavior in a lattice-gas model for the monomor-dimer reaction on surfaces. This model. which mimics catalytic CO-oxidation, includes a mobile monomer adspecies (representing CO), an immobile dissociatively adsorbed dimer species (representing O), and a finite reaction rate (for CO2 production). We characterize in detail the propagation of the chemical wave or reaction front produced when the stable reactive steady-state of the model displaces the metastable. CO-poisoned state, In the regime of high CO-mobility, such propagation can be described directly within a "hydrodynamic" reaction-diffusion equation formalism. However, we show that the chemical diffusivity of CO is dependent on the O coverage, reflecting the percolative nature of CO-transport through a background of immobile O. We also emphasize that gradients in the coverage of immobile O induce a diffusive flux in the highly mobile CO. These features significantly influence wave propagation and reaction front structure. In addition, our analysis accounts for the feature that in this hydrodynamic regime, correlations persist in the distribution of adsorbed immobile O, and that these influence the reaction kinetics, the steady states, and the percolation and diffusion properties. To this end, we utilize a "hybrid" approach which incorporates a mean-field reaction-diffusion treatment of adsorbed CO, coupled with a lattice-gas treatment of adsorbed O [Tammaro et al., J. Chem. Phys. 103, 10277 (1995)]. (C) 1998 American Institute of Physics. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. Iowa State Univ, Dept Phys, Ames, IA 50011 USA. Iowa State Univ, Dept Math, Ames, IA 50011 USA. RP Tammaro, M (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 45 TC 41 Z9 42 U1 0 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 1998 VL 108 IS 2 BP 762 EP 773 DI 10.1063/1.475436 PG 12 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP022 UT WOS:000071233400043 ER PT J AU Jiang, JW Liu, HL Hu, Y Prausnitz, JM AF Jiang, JW Liu, HL Hu, Y Prausnitz, JM TI A molecular-thermodynamic model for polyelectrolyte solutions SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID STATISTICAL MECHANICAL MODELS; PERCUS-YEVICK APPROXIMATION; POLY-ELECTROLYTE SOLUTIONS; MEAN SPHERICAL MODEL; POISSON-BOLTZMANN; COUNTERION CONDENSATION; ASYMMETRIC ELECTROLYTES; CHEMICAL ASSOCIATION; ANALYTIC SOLUTION; LIMITING LAWS AB Polyelectrolyte solutions are modeled as freely tangent-jointed, charged hard-sphere chains and corresponding counterions in a continuum medium with permitivity E. By adopting the sticky-point model, the Helmholtz function for polyelectrolyte solutions is derived through the r-particle cavity-correlation function (CCF) for chains of sticky, charged hard spheres. The r-CCF is approximated by a product of effective nearest-neighbor two-particle CCFs: these are determined from the hypernetted-chain and mean-spherical closures (HNC/MSA) inside and outside the hard core, respectively, for the integral equation theory for electrolytes. The colligative properties are given as explicit functions of a scaling parameter Gamma that can be estimated by a simple iteration procedure. Osmotic pressures, osmotic coefficients, and activity coefficients are calculated for model solutions with various chain lengths. They are in good agreement with molecular simulation and experimental results. (C) 1998 American Institute of Physics. C1 E China Univ Sci & Technol, Thermodynam Res Lab, Shanghai 200237, Peoples R China. Univ Calif Berkeley, Dept Chem Engn, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Hu, Y (reprint author), E China Univ Sci & Technol, Thermodynam Res Lab, Shanghai 200237, Peoples R China. RI JIANG, Jianwen/G-1505-2013; OI Jiang, Jianwen/0000-0003-1310-9024 NR 33 TC 56 Z9 61 U1 0 U2 8 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 1998 VL 108 IS 2 BP 780 EP 784 DI 10.1063/1.475438 PG 5 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP022 UT WOS:000071233400045 ER PT J AU Chang, TM Dang, LX AF Chang, TM Dang, LX TI Transfer of chloroform across the water-carbon tetrachloride liquid-liquid interface SO JOURNAL OF CHEMICAL PHYSICS LA English DT Article ID MOLECULAR-DYNAMICS; SIMULATIONS; MEMBRANE; SOLUTES C1 Pacific NW Lab, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Chang, TM (reprint author), Pacific NW Lab, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. NR 15 TC 12 Z9 12 U1 1 U2 2 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0021-9606 J9 J CHEM PHYS JI J. Chem. Phys. PD JAN 8 PY 1998 VL 108 IS 2 BP 818 EP 819 DI 10.1063/1.475441 PG 2 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA YP022 UT WOS:000071233400050 ER PT J AU Lutt, M Fitzsimmons, MR Li, DQ AF Lutt, M Fitzsimmons, MR Li, DQ TI X-ray reflectivity study of self-assembled thin films of macrocycles and macromolecules SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID STRUCTURAL CHARACTERIZATION; MONOLAYERS; SURFACES; GOLD; MULTILAYERS; SCATTERING AB The layer-by-layer growth of film structures consisting of sequential depositions of oppositely charged macromolecules (polymers) and macrocycles (ring-shaped molecules) has been carried out using the self-assembly technique. These self-assembled structures were characterized with X-ray reflectometry, results from which indicate (1) the average electron density of the sample measured after a sequential deposition of macromolecules followed by macrocycles remained the same regardless of the number of depositions made, while (2) the average thicknesses of alternately deposited macromolecules and macrocycles deposited at the beginning of the fabrication were larger than those deposited after many depositions and (3) the roughness of the growth surface generally increased with each deposition. These observations suggest that inorganic-organic interactions play an important role during the initial stages of thin-film growth, but less so as the thin film becomes thicker. C1 Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST4, Los Alamos, NM 87545 USA. Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering Ctr, Los Alamos, NM 87545 USA. RP Li, DQ (reprint author), Univ Calif Los Alamos Natl Lab, Chem Sci & Technol Div CST4, POB 1663, Los Alamos, NM 87545 USA. RI Lujan Center, LANL/G-4896-2012 NR 23 TC 45 Z9 45 U1 0 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 8 PY 1998 VL 102 IS 2 BP 400 EP 405 DI 10.1021/jp9723473 PG 6 WC Chemistry, Physical SC Chemistry GA YR895 UT WOS:000071542300013 ER PT J AU Zaban, A Ferrere, S Gregg, BA AF Zaban, A Ferrere, S Gregg, BA TI Relative energetics at the semiconductor sensitizing dye electrolyte interface SO JOURNAL OF PHYSICAL CHEMISTRY B LA English DT Article ID NANOCRYSTALLINE TIO2 FILMS; CHARGE-TRANSFER SENSITIZERS; SOLAR-CELL; PHOTOELECTROCHEMICAL CELLS; POTENTIAL DISTRIBUTION; TRANSFER KINETICS; BAND ENERGETICS; METAL-COMPLEXES; SOLID-STATE; CONVERSION AB Chemical oxidation, spectro-electrochemical reduction, and potential-dependent photoluminescence were employed to investigate changes in the redox potential of eight different adsorbed sensitizing dyes relative to the potentials of the semiconductor and the electrolyte solution. The redox potentials of the investigated dyes were pH-independent in solution but developed a pH dependence that varied between 21 and 53 mV per pH unit upon adsorption to an oxide surface. Electrochemical experiments show that the apparent redox potential of the dye could also be influenced by an external bias applied to the electrode. The adsorption-induced potential changes were found to depend on both the dye structure and the electrolyte composition. A proposed model that considers the position of the specifically adsorbed dye relative to the ionic double layer at the electrode/electrolyte interface explains these results qualitatively. When the dye is mostly inside the double layer, its potential will tend to follow changes in the semiconductor potential; when it is mostly outside, its potential will be almost independent of the semiconductor. The fact that the potential of the sensitizing dye is not fixed relative to either the semiconductor or the electrolyte solution has important implications for the understanding and optimization of dye-sensitized cells. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP Zaban, A (reprint author), Bar Ilan Univ, Dept Chem, IL-52900 Ramat Gan, Israel. NR 55 TC 169 Z9 169 U1 1 U2 21 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 1089-5647 J9 J PHYS CHEM B JI J. Phys. Chem. B PD JAN 8 PY 1998 VL 102 IS 2 BP 452 EP 460 DI 10.1021/jp972924n PG 9 WC Chemistry, Physical SC Chemistry GA YR895 UT WOS:000071542300019 ER PT J AU Chambers, JQ Higuchi, N Schimel, JP AF Chambers, JQ Higuchi, N Schimel, JP TI Ancient trees in Amazonia SO NATURE LA English DT Letter ID FOREST; IMPACT C1 Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. Univ Calif Lawrence Livermore Natl Lab, Hlth & Ecol Assessment Div, Livermore, CA 94550 USA. Inst Nacl Pesquisas Amazonia, BR-69011 Manaus, Amazonas, Brazil. RP Chambers, JQ (reprint author), Univ Calif Santa Barbara, Dept Ecol Evolut & Marine Biol, Santa Barbara, CA 93106 USA. RI Chambers, Jeffrey/J-9021-2014 OI Chambers, Jeffrey/0000-0003-3983-7847 NR 8 TC 131 Z9 138 U1 1 U2 24 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 8 PY 1998 VL 391 IS 6663 BP 135 EP 136 DI 10.1038/34325 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YQ378 UT WOS:000071380900034 ER PT J AU Hemminki, A Markie, D Tomlinson, I Avizienyte, E Roth, S Loukola, A Bignell, G Warren, W Aminoff, M Hoglund, P Jarvinen, H Kristo, P Pelin, K Ridanpaa, M Salovaara, R Toro, T Bodmer, W Olschwang, S Olsen, AS Stratton, MR de la Chapelle, A Aaltonen, LA AF Hemminki, A Markie, D Tomlinson, I Avizienyte, E Roth, S Loukola, A Bignell, G Warren, W Aminoff, M Hoglund, P Jarvinen, H Kristo, P Pelin, K Ridanpaa, M Salovaara, R Toro, T Bodmer, W Olschwang, S Olsen, AS Stratton, MR de la Chapelle, A Aaltonen, LA TI A serine/threonine kinase gene defective in Peutz-Jegheus syndrome SO NATURE LA English DT Article ID MUTATIONS; CANCER AB Studies of hereditary cancer syndromes have contributed greatly to our understanding of molecular events involved in tumorigenesis. Here we investigate the molecular background of the Peutz-Jeghers syndrome(1,2) (PJS), a rare hereditary disease in which there is predisposition to benign and malignant tumours of many organ systems. A locus for this condition was recently assigned to chromosome 19p (ref. 3). We have identified truncating germline mutations in a gene residing on chromosome 19p in multiple individuals affected by PJS. This previously identified but unmapped gene, LKB1 (ref. 4), has strong homology to a cytoplasmic Xenopus serine/threonine protein kinase XEEK1 (ref. 5), and weaker similarity to many other protein kinases. Peutz-Jeghers syndrome is therefore the first cancer-susceptibility syndrome to be identified that is due to inactivating mutations in a protein kinase. C1 Univ Helsinki, Haartman Inst, Dept Med Genet, FIN-00014 Helsinki, Finland. Univ Helsinki, Haartman Inst, Dept Pathol, FIN-00014 Helsinki, Finland. Dunedin Sch Med, Dept Pathol, Dunedin, New Zealand. Inst Canc Res, Haddow Labs, Sect Canc Genet, Sutton SM2 5NG, Surrey, England. John Radcliffe Hosp, Nuffield Dept Clin Med, Oxford OX3 9DU, England. Univ Helsinki, Cent Hosp, Dept Surg 2, FIN-00290 Helsinki, Finland. Folkhalsan Inst Genet, Helsinki 00280, Finland. John Radcliffe Hosp, Inst Mol Med, Imperial Canc Res Fund, Canc & Immunogenet Lab, Oxford OX3 9DS, England. Fdn Jean Dausset CEPH, INSERM, U434, F-75010 Paris, France. Univ Calif Lawrence Livermore Natl Lab, Ctr Human Genome, Livermore, CA 94550 USA. Ohio State Univ, Ctr Comprehens Canc, Columbus, OH 43210 USA. RP Aaltonen, LA (reprint author), Univ Helsinki, Haartman Inst, Dept Med Genet, POB 21 Haartmaninkatu 3, FIN-00014 Helsinki, Finland. EM Lauri.Aaltonen@Helsinki.Fi RI Olschwang, Sylviane/G-2716-2013; Aaltonen, Lauri/A-5375-2010; OI Aaltonen, Lauri/0000-0001-6839-4286; Bodmer, Walter/0000-0001-6244-9792 NR 15 TC 918 Z9 975 U1 6 U2 28 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 8 PY 1998 VL 391 IS 6663 BP 184 EP 187 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YQ378 UT WOS:000071380900053 PM 9428765 ER PT J AU Nogales, E Wolf, SG Downing, KH AF Nogales, E Wolf, SG Downing, KH TI Structure of the alpha beta tubulin dimer by electron crystallography SO NATURE LA English DT Article ID TAXOL-BINDING-SITE; COLCHICINE-BINDING; EXCHANGEABLE GTP; GUANOSINE TRIPHOSPHATE; BRAIN BETA-1-TUBULIN; AMINO-ACIDS; MICROTUBULE; HYDROLYSIS; LOCALIZATION; PHOTOLABELS AB The alpha beta tubulin heterodimer is the structural subunit of microtubules, which are cytoskeletal elements that are essential for intracellular transport and cell division in all eukaryotes. Each tubulin monomer binds a guanine nucleotide, which is non-exchangeable when it is bound in the alpha subunit, or N site, and exchangeable when bound in the beta subunit, or E site. The alpha- and beta-tubulins share 40% amino-acid sequence identity, both exist in several isotype forms, and both undergo a variety of posttranslational modifications'. Limited sequence homology has been found with the proteins FtsZ(2) and Misato(3), which are involved in cell division in bacteria and Drosophila, respectively. Here we present an atomic model of the alpha beta tubulin dimer fitted to a 3.7-Angstrom density map obtained by electron crystallography of zinc-induced tubulin sheets. The structures of alpha- and beta-tubulin are basically identical: each monomer is formed by a core of two beta-sheets surrounded by alpha-helices. The monomer structure is very compact, but can be divided into three functional domains: the amino-terminal domain containing the nucleotide-binding region, an intermediate domain containing the Taxol-binding site, and the carboxy-terminal domain, which probably constitutes the binding surface for motor proteins. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Nogales, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RI WOLF, SHARON/K-1768-2012 OI WOLF, SHARON/0000-0002-5337-5063 NR 30 TC 1429 Z9 1475 U1 19 U2 133 PU MACMILLAN MAGAZINES LTD PI LONDON PA PORTERS SOUTH, 4 CRINAN ST, LONDON, ENGLAND N1 9XW SN 0028-0836 J9 NATURE JI Nature PD JAN 8 PY 1998 VL 391 IS 6663 BP 199 EP 203 DI 10.1038/34465 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YQ378 UT WOS:000071380900057 PM 9428769 ER PT J AU Kisslinger, LS Goldman, T Li, Z AF Kisslinger, LS Goldman, T Li, Z TI QED penguin contributions to isospin splittings of heavy-light quark systems SO PHYSICS LETTERS B LA English DT Article ID SYMMETRY-BREAKING; QCD AB Recent experiments show that the isospin-violating mass splitting of the B mesons is very small, but the best fits with a QCD sum rule analysis give a splitting of at least 1.0 MeV. The isospin-violating mass splittings of the charmed mesons, on the other hand, are in agreement with experiment, In this letter we show that the inclusion of 2nd kind QED penguin diagrams can account for this discrepancy within the errors in the QCD sum rule method. (C) 1998 Elsevier Science B.V. C1 Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. Univ Calif Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. Peking Univ, Beijing 100871, Peoples R China. RP Kisslinger, LS (reprint author), Carnegie Mellon Univ, Dept Phys, Pittsburgh, PA 15213 USA. NR 10 TC 3 Z9 3 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 8 PY 1998 VL 416 IS 3-4 BP 263 EP 267 DI 10.1016/S0370-2693(97)01321-X PG 5 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YW029 UT WOS:000071888500002 ER PT J AU Hackman, G Janssens, RVF Moore, EF Nisius, D Ahmad, I Carpenter, MP Fischer, SM Khoo, TL Lauritsen, T Reiter, P AF Hackman, G Janssens, RVF Moore, EF Nisius, D Ahmad, I Carpenter, MP Fischer, SM Khoo, TL Lauritsen, T Reiter, P TI Lifetime measurements of superdeformed bands in Sm-142: A test of the additivity principle for quadrupole moments SO PHYSICS LETTERS B LA English DT Article ID GD-146; NUCLEI AB Lifetime measurements with the Doppler shift attenuation method have been performed for the two superdeformed (SD) bands of Sm-142. The inferred transition quadrupole moments, Q(0),, are 11.7 +/- 0.1 eb for the yrast SD band and 13.2(-0.7)(+0.8) eb for the excited SD band. These results are consistent with expectations from mean-field calculations, and indicate that the proposed additivity of contributions of individual orbitals to Q(0), is valid for SD nuclei over an extended mass range in the vicinity of Dy-152. Published by Elsevier Science B.V. C1 Argonne Natl Lab, Argonne, IL 60439 USA. N Carolina State Univ, Raleigh, NC 27695 USA. Triangle Univ Nucl Lab, Durham, NC 27708 USA. RP Hackman, G (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 23 TC 16 Z9 16 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0370-2693 J9 PHYS LETT B JI Phys. Lett. B PD JAN 8 PY 1998 VL 416 IS 3-4 BP 268 EP 273 DI 10.1016/S0370-2693(97)01244-6 PG 6 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YW029 UT WOS:000071888500003 ER PT J AU Lykken, J Poppitz, E Trivedi, SP AF Lykken, J Poppitz, E Trivedi, SP TI Chiral gauge theories from D-branes SO PHYSICS LETTERS B LA English DT Article AB We construct brane configurations leading to chiral four dimensional N=1 supersymmetric gauge theories. The brane realizations consist of intersecting Neveu-Schwarz five-branes and Dirichlet four-branes in non-flat spacetime backgrounds. We discuss in some detail the construction in a C-2/Z(M) orbifold background. The infrared theory on the four-brane worldvolume is a four dimensional N=1 SU(N)(M) gauge theory with chiral matter representations. We discuss various consistency checks and show that the spectral curves describing the Coulomb phase of the theory can be obtained once the orbifold brane construction is embedded in M-theory. We also discuss the addition of extra vectorlike matter and other interesting generalizations. (C) 1998 Published by Elsevier Science B.V. C1 Fermilab Natl Accelerator Lab, Batavia, IL 60510 USA. Univ Chicago, Enrico Fermi Inst, Chicago, IL 60637 USA. RP Fermilab Natl Accelerator Lab, POB 500, Batavia, IL 60510 USA. NR 34 TC 42 Z9 42 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 JAN 8 PY 1998 VL 416 IS 3-4 BP 286 EP 294 DI 10.1016/S0370-2693(97)01220-3 PG 9 WC Astronomy & Astrophysics; Physics, Nuclear; Physics, Particles & Fields SC Astronomy & Astrophysics; Physics GA YW029 UT WOS:000071888500006 ER PT J AU Zalka, C AF Zalka, C TI Simulating quantum systems on a quantum computer SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT ITP Conference on Quantum Coherence and Decoherence CY DEC 15-18, 1996 CL SANTA BARBARA, CA SP ITP DE quantum computers; simulated decay; fermionic field theories; one-dimensional particle; energy spectrum ID COMPUTATION AB We show that the time evolution of the wave function of a quantum-mechanical many-particle system can be simulated precisely and efficiently on a quantum computer. The time needed for such a simulation is comparable to the time of a conventional simulation of the corresponding classical system, a performance which can't be expected from any classical simulation of a quantum system. We then show how quantities of interest, like the energy spectrum of a system, can be obtained. We also indicate that ultimately the simulation of quantum field theory might be possible on large quantum computers. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Zalka, C (reprint author), Los Alamos Natl Lab, T-6,MS B288, Los Alamos, NM 87545 USA. NR 28 TC 136 Z9 137 U1 0 U2 5 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 8 PY 1998 VL 454 IS 1969 BP 313 EP 322 DI 10.1098/rspa.1998.0162 PG 10 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT736 UT WOS:000071639900005 ER PT J AU Paz, JP Zurek, WH AF Paz, JP Zurek, WH TI Continuous error correction SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT ITP Conference on Quantum Coherence and Decoherence CY DEC 15-18, 1996 CL SANTA BARBARA, CA SP ITP DE error correction; master equation; stabilizer codes; corrective quantum jumps ID QUANTUM AB We propose a new approach to study the evolution of a quantum state that is encoded in a system which is continuously subjected to the operations required to implement a quantum error-correcting code. In the limit of continuous error correction we introduce a Markovian master equation that includes the effects of: (a) Hamiltonian evolution; (b) errors caused by the interaction with an environment; and (c) error-correcting operations. The master equation is formally presented for all stabilizer codes and its solution is analysed for the simplest such code. C1 Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Fis JJ Giambiagi, RA-1428 Buenos Aires, DF, Argentina. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Paz, JP (reprint author), Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Fis JJ Giambiagi, Pabellon 1,Ciudad Univ, RA-1428 Buenos Aires, DF, Argentina. RI Paz, Juan/C-5947-2008 NR 13 TC 17 Z9 17 U1 0 U2 1 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 8 PY 1998 VL 454 IS 1969 BP 355 EP 364 PG 10 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT736 UT WOS:000071639900008 ER PT J AU Knill, E Laflamme, R Zurek, WH AF Knill, E Laflamme, R Zurek, WH TI Resilient quantum computation: error models and thresholds SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT ITP Conference on Quantum Coherence and Decoherence CY DEC 15-18, 1996 CL SANTA BARBARA, CA SP ITP DE quantum computation; quantum information; error correction; fault tolerance ID CORRECTING CODES; LOGIC GATE; UNIVERSAL; ENTANGLEMENT AB Recent research has demonstrated that quantum computers can solve certain types of problems substantially faster than the known classical algorithms. These problems include factoring integers and certain physics simulations. Practical quantum computation requires overcoming the problems of environmental noise and operational errors, problems which appear to be much more severe than in classical computation, due to the inherent fragility of quantum superpositions involving many degrees of freedom. Here we show that arbitrarily accurate quantum computations are possible provided that the error per operation is below a threshold value. The result is obtained by combining quantum error-correction, fault-tolerant state recovery, fault-tolerant encoding of operations and concatenation. It holds under physically realistic assumptions on the errors. C1 Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Knill, E (reprint author), Los Alamos Natl Lab, CIC-3,MS B265, Los Alamos, NM 87545 USA. NR 37 TC 176 Z9 177 U1 0 U2 7 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 8 PY 1998 VL 454 IS 1969 BP 365 EP 384 PG 20 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT736 UT WOS:000071639900009 ER PT J AU Chuang, IL Gershenfeld, N Kubinec, MG Leung, DW AF Chuang, IL Gershenfeld, N Kubinec, MG Leung, DW TI Bulk quantum computation with nuclear magnetic resonance: theory and experiment SO PROCEEDINGS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES LA English DT Article; Proceedings Paper CT ITP Conference on Quantum Coherence and Decoherence CY DEC 15-18, 1996 CL SANTA BARBARA, CA SP ITP DE quantum mechanics; quantum computation; NMR; spin resonance; decoherence; entanglement ID COMPUTERS; LOGIC; PHASE; GATES AB We show that quantum computation is possible with mixed states instead of pure states as inputs. This is performed by embedding within the mixed state a subspace that transforms like a pure state and that can be identified by labelling based on logical (spin), temporal, or spatial degrees of freedom. This permits quantum computation to be realized with bulk ensembles far from the ground state. Experimental results are presented for quantum gates and circuits implemented with liquid nuclear magnetic resonance techniques and verified by quantum state tomography. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. MIT, Media Lab, Phys & Media Grp, Cambridge, MA 02139 USA. Univ Calif Berkeley, Coll Chem, Berkeley, CA 94720 USA. Stanford Univ, Ginzton Lab, ERATO, Quantum Fluctuat Project, Stanford, CA 94305 USA. RP Chuang, IL (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop B288, Los Alamos, NM 87545 USA. NR 30 TC 216 Z9 229 U1 0 U2 10 PU ROYAL SOC PI LONDON PA 6-9 CARLTON HOUSE TERRACE, LONDON SW1Y 5AG, ENGLAND SN 1364-5021 EI 1471-2946 J9 P ROY SOC A-MATH PHY JI Proc. R. Soc. A-Math. Phys. Eng. Sci. PD JAN 8 PY 1998 VL 454 IS 1969 BP 447 EP 467 PG 21 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YT736 UT WOS:000071639900013 ER PT J AU Liu, FQ Tilley, TD AF Liu, FQ Tilley, TD TI A coordination network based on d(0) transition-metal centers: synthesis and structure of the [2,4]-connected layered compound [(TiCl(4))(2)Si(C(6)H(4)CN-p)(4)]center dot 1.5C(7)H(8) SO CHEMICAL COMMUNICATIONS LA English DT Article ID MOLECULES; FRAMEWORKS; SILVER(I); LIGANDS AB The tetrafunctional silane Si(C(6)H(4)CN-p)(4) forms a coordination network with TiCl(4) consisting of 4,2-connected layers containing large (56 atom) rings. C1 Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Chem Sci, Berkeley, CA 94720 USA. RP Tilley, TD (reprint author), Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA. EM tdtilley@socrates.berkeley.edu NR 22 TC 16 Z9 16 U1 0 U2 0 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND SN 1359-7345 J9 CHEM COMMUN JI Chem. Commun. PD JAN 7 PY 1998 IS 1 BP 103 EP 104 DI 10.1039/a706020c PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA YT355 UT WOS:000071593500049 ER PT J AU Mao, B Hingerty, BE Broyde, S Patel, DJ AF Mao, B Hingerty, BE Broyde, S Patel, DJ TI Solution structure of the aminofluorene [AF]-intercalated conformer of the syn-[AF]-C-8-dG adduct opposite dC in a DNA duplex SO BIOCHEMISTRY LA English DT Article ID 2 INTERCHANGEABLE CONFORMATIONS; NUCLEAR MAGNETIC-RESONANCE; C-8-MODIFIED SYN GUANINE; CARCINOGEN N-2-ACETYLAMINOFLUORENE; COMPUTATIONAL CHARACTERIZATION; 2-AMINOFLUORENE-MODIFIED DNA; ENERGY MINIMIZATION; BASE DISPLACEMENT; ESCHERICHIA-COLI; DG OPPOSITE AB We report below on a conformational equilibrium between AF-intercalated and AF-external states in slow exchange for the [AF]dG lesion positioned opposite dC in the d(C-[AF]G-C) d(G-C-G) sequence context, The slow exchange between states is attributed to interconversion between syn glycosidic torsion angle in the AF-intercalated and anti torsion angle in AF-external conformers of the [AF]dG opposite dC containing duplex. The present paper describes an NMR-molecular mechanics study that defines the solution structure of the AF-intercalated conformer for the case of [AF]dG adduct positioned opposite dC in the d(C-[AF]G-C).d(G-C-G) sequence context. The structure is of the base displacement-intercalation type where the aminofluorene ring is intercalated into the helix between intact Watson-Crick dG.dC base pairs, which results in a displacement of the modified guanine ring into the major groove where it stacks with the major groove edge of its 5'-flanking cytosine in the adduct duplex. The conformational equilibrium between AF-intercalated conformer (similar to 70%) with a syn alignment and AF-external conformer (similar to 30%) with an anti alignment for the [AF]dG adduct positioned opposite dC in the d(C-[AF]G-C).d(G-C-G) sequence context can be contrasted with our earlier demonstration that the population is 100% for the AP-intercalated conformer with a syn alignment at the N-(deoxyguanosin-8-yl)-2-aminopyrene ([AP]dG) adduct site positioned opposite dC in the same sequence context [Mao, B,, Vyas, R. R., Hingerty, B, E,, Broyde, S,, Basu, A, K., and Patel, D, J. (1996) Biochemistry, 35, 12659-12670]. This shift in population may reflect the much larger size of the pyrenyl ring of the [AP]dG adduct compared to the fluorenyl ring of the [AF]dG adduct which in turn might provide for a greater overlap of the aromatic amine with the flanking base pairs in the intercalated conformer of the former adduct in DNA. C1 Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, New York, NY 10021 USA. Oak Ridge Natl Lab, Hlth Sci Res Div, Oak Ridge, TN 37831 USA. NYU, Dept Biol, New York, NY 10003 USA. RP Patel, DJ (reprint author), Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, 1275 York Ave, New York, NY 10021 USA. FU NCI NIH HHS [CA-28038, CA-75449, CA-49982] NR 53 TC 61 Z9 61 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 6 PY 1998 VL 37 IS 1 BP 81 EP 94 DI 10.1021/bi972257o PG 14 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YR517 UT WOS:000071503200010 PM 9425028 ER PT J AU Mao, B Hingerty, BE Broyde, S Patel, DJ AF Mao, B Hingerty, BE Broyde, S Patel, DJ TI Solution structure of the aminofluorene [AF]-external conformer of the anti-[AF]-C-8-dG adduct opposite dC in a DNA duplex SO BIOCHEMISTRY LA English DT Article ID MUTATION HOT-SPOT; SINGLE ACETYLAMINOFLUORENE ADDUCT; 2 INTERCHANGEABLE CONFORMATIONS; NUCLEAR MAGNETIC-RESONANCE; C-8-MODIFIED SYN GUANINE; ENERGY MINIMIZATION; BASE DISPLACEMENT; ESCHERICHIA-COLI; DG OPPOSITE; MAJOR GROOVE AB The Escherichia coli genome contains a C-G(1)-G(2)-C-G(3)-C-C NarI hot spot sequence for -2 deletion mutations at G(3) by aromatic amine carcinogens 2-acetylaminofluorene (AAF) and 2-aminofluorene (AF) that form covalent adducts at the C-8-position of the guanine ring, Each of the three guanines are positioned in different sequence contexts (C-G(1)-G, G-G(2)-C, and C-G(3)-C) which provides an opportunity to investigate the potential sequence dependent interconversion between AF-intercalated and AF-external conformers of the [AF]dG adduct positioned opposite dC within the NarI sequence at the duplex level. We have prepared and purified DNA duplexes containing the [AF]dG adduct positioned in C-[AF]G-G, G-[AF]G-C, and C-[AF]G-C NarI sequence contexts and observe the ratio of AF-intercalated to AF-external conformers to be 30:70, 10:90, and 50:50, respectively. We have applied a combined NMR-molecular mechanics approach to define the structure of the AF-external conformer in the G-[AF]G-C NarI sequence context where it is the predominant conformation (90%) in solution. The modified guanine of the [AF]dG adduct aligns through Watson-Crick pairing with its partner cytosine and is stacked into the helix between flanking Watson-Crick dG.dC base pairs, The AF-external conformer with its anti[AF]dG residue causes minimal perturbations in the DNA duplex at and adjacent to the lesion site with the covalently linked fluorenyl ring readily accommodated in the major groove and tilted toward the 5'-end of the modified strand of the helix. This paper on the structure of the AF-external conformer with an anti-[AF]dG adduct together with the preceding paper in this issue on the structure of the AF-intercalated conformer with a syn-[AF]dG adduct defines for the first time the capacity of the mutagenic [AF]dG lesion to adopt interconverting syn and anti alignments with the equilibrium shifting between the conformers depending on nearest neighbor and next-nearest neighbor sequences, Perhaps, recognition of the [AF]dG lesion by the repair machinery would be able to discriminate between the AF-intercalated conformer with its base displacement-fluorenyl ring insertion perturbation of the helix and the AF-external conformer where the DNA helix is essentially unperturbed at the lesion site and the fluorenyl ring is positioned with directionality in the major groove. C1 Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, New York, NY 10021 USA. Oak Ridge Natl Lab, Hlth Sci Res Div, Oak Ridge, TN 37831 USA. NYU, Dept Biol, New York, NY 10003 USA. RP Patel, DJ (reprint author), Mem Sloan Kettering Canc Ctr, Cellular Biochem & Biophys Program, 1275 York Ave, New York, NY 10021 USA. FU NCI NIH HHS [CA-49982, CA-75449, CA-28038] NR 33 TC 54 Z9 54 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0006-2960 J9 BIOCHEMISTRY-US JI Biochemistry PD JAN 6 PY 1998 VL 37 IS 1 BP 95 EP 106 DI 10.1021/bi972258g PG 12 WC Biochemistry & Molecular Biology SC Biochemistry & Molecular Biology GA YR517 UT WOS:000071503200011 PM 9425029 ER PT J AU Hostetler, MJ Wingate, JE Zhong, CJ Harris, JE Vachet, RW Clark, MR Londono, JD Green, SJ Stokes, JJ Wignall, GD Glish, GL Porter, MD Evans, ND Murray, RW AF Hostetler, MJ Wingate, JE Zhong, CJ Harris, JE Vachet, RW Clark, MR Londono, JD Green, SJ Stokes, JJ Wignall, GD Glish, GL Porter, MD Evans, ND Murray, RW TI Alkanethiolate gold cluster molecules with core diameters from 1.5 to 5.2 nm: Core and monolayer properties as a function of core size SO LANGMUIR LA English DT Review ID SELF-ASSEMBLED MONOLAYERS; ANGLE X-RAY; COLLOIDAL PLATINUM NANOPARTICLES; STABILIZED METAL-CLUSTERS; ORGANIC-SURFACES; STRUCTURAL CHARACTERIZATION; NANOSTRUCTURED MATERIALS; INFRARED-SPECTROSCOPY; 3 DIMENSIONS; SOLID-STATE AB The mean size of the gold (Au) core in the synthesis of dodecanethiolate-stabilized Au cluster compounds can be finely adjusted by choice of the Au:dodecanethiolate ratio and the temperature and rate at which the reduction is conducted. The Au clusters have been examined with a large number of independent analytical tools, producing a remarkably consistent picture of these materials. Average cluster and core dimensions, as ascertained by H-1 NMR line broadening, high-resolution transmission electron microscopy, small-angle X-ray scattering, and thermogravimetric analysis, vary between diameters of 1.5 and 5.2 nm (similar to 110-4800 Au atoms/core). The electronic properties of the Au core were examined by UV/vis and X-ray photoelectron spectroscopy; the core appears to remain largely metallic in nature even at the smallest core sizes examined. The alkanethiolate monolayer stabilizing the Au core ranges with core size from similar to 53 to nearly 520 ligands/core, and was probed by Fourier transform infrared spectroscopy, differential scanning calorimetry, contact-angle measurements, and thermal desorption mass spectrometry. The dodecanethiolate monolayer on small and large core clusters exhibits discernable differences; the line dividing "3-dimensional" monolayers and those resembling self-assembled monolayers on flat Au (2-dimensional monolayers) occurs at clusters with similar to 4.4 nm core diameters. C1 Univ N Carolina, Kenan Labs Chem, Chapel Hill, NC 27599 USA. Iowa State Univ, Dept Chem, Ames, IA 50011 USA. Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. Oak Ridge Inst Sci & Educ, Oak Ridge, TN 37831 USA. RP Murray, RW (reprint author), Univ N Carolina, Kenan Labs Chem, Chapel Hill, NC 27599 USA. RI Evans, Neal/F-5955-2011; bee, betty/G-1104-2011; Zhong, Chuan-Jian/D-3394-2013 NR 104 TC 1466 Z9 1480 U1 38 U2 463 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JAN 6 PY 1998 VL 14 IS 1 BP 17 EP 30 DI 10.1021/la970588w PG 14 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YQ945 UT WOS:000071440700003 ER PT J AU Godinez, LA Lin, J Munoz, M Coleman, AW Rubin, S Parikh, A Zawodzinski, TA Loveday, D Ferraris, JP Kaifer, AE AF Godinez, LA Lin, J Munoz, M Coleman, AW Rubin, S Parikh, A Zawodzinski, TA Loveday, D Ferraris, JP Kaifer, AE TI Multilayer self-assembly of amphiphilic cyclodextrin hosts on bare and modified gold substrates: Controlling aggregation via surface modification SO LANGMUIR LA English DT Article ID ADAMANTANECARBOXYLATE INCLUSION COMPLEXES; INTERFACIAL BINDING-PROPERTIES; ENTHALPY-ENTROPY COMPENSATION; QUARTZ CRYSTAL MICROBALANCE; MOLECULAR RECOGNITION; BETA-CYCLODEXTRIN; ELECTRODE SURFACES; CALORIMETRIC TITRATION; ALPHA-CYCLODEXTRIN; MONOLAYER FILMS AB Self-assembled multilayers of the three modified cyclodextrins (hexakis(2,3-O-hexyl-6-deoxy-6-amino)-alpha-cyclodextrin (1), heptakis(2,3-O-hexyl-6-deoxy-6-amino)-beta-cyclodextrin (2), and octakis(2,3-O-hexyl-6-deoxy-6-amino)-gamma-cyclodextrin (3)) on bare gold, as well as on gold surfaces modified with mercaptopropionic (4) and mercaptooctanoic (5) acid, were investigated by cyclic voltammetric, contact angle, FT-IR, and quartz crystal microbalance measurements in neutral aqueous media. The level of organization of the aggregates formed by the three CD derivatives (1-3) on the negatively charged surface of the mercaptopropionic and mercaptooctanoic acid modified gold electrodes proved to be substantially better than that on bare gold electrodes. This finding suggests that although the amphiphilic character of compounds 1-3 can induce aggregation on a gold surface, the electrostatic interaction between the carboxylic acid groups and the positively charged cyclodextrins is the primary force leading to the formation of well-organized aggregates. C1 Univ Miami, Dept Chem, Coral Gables, FL 33124 USA. CNRS, UPR 412, IBCP 7, F-69367 Lyon, France. Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. Univ Texas, Dept Chem, Richardson, TX 75083 USA. RP Kaifer, AE (reprint author), Univ Miami, Dept Chem, Coral Gables, FL 33124 USA. RI PARIKH, ATUL/D-2243-2014 OI PARIKH, ATUL/0000-0002-5927-4968 NR 53 TC 32 Z9 32 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0743-7463 J9 LANGMUIR JI Langmuir PD JAN 6 PY 1998 VL 14 IS 1 BP 137 EP 144 DI 10.1021/la970749w PG 8 WC Chemistry, Multidisciplinary; Chemistry, Physical; Materials Science, Multidisciplinary SC Chemistry; Materials Science GA YQ945 UT WOS:000071440700017 ER PT J AU Schramm, DN AF Schramm, DN TI Primordial nucleosynthesis SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT National-Academy-of-Sciences Colloquium on the Age of the Universe, Dark Matter, and Structure Formation CY MAR 21-23, 1997 CL ARNOLD & MABEL BECKMAN CTR NAT ACAD SCI & ENGN, IRVINE, CALIFORNIA SP Natl Acad Sci HO ARNOLD & MABEL BECKMAN CTR NAT ACAD SCI & ENGN ID BIG-BANG NUCLEOSYNTHESIS; NEUTRON LIFETIME; HALO-STARS; INTERSTELLAR-MEDIUM; ULTRACOLD NEUTRONS; DARK-MATTER; ABUNDANCE; LITHIUM; UNIVERSE; HE-3 AB With the advent of the new extragalactic deuterium observations, Big Bang nucleosynthesis (BBN) is on the verge of undergoing a transformation. In the past, the emphasis has been on demonstrating the concordance of the BBN model with the abundances of the light isotopes extrapolated back to their primordial values by using stellar and galactic evolution theories, As a direct measure of primordial deuterium is converged upon, the nature of the field will shift to using the much more precise primordial D/H to constrain the more flexible stellar and galactic evolution models (although the question of potential systematic error in He-4 abundance determinations remains open). The remarkable success of the theory to date in establishing the concordance has led to the very robust conclusion of BBN regarding the baryon density. This robustness remains even through major model variations such as an assumed first-order quark-hadron phase transition. The BBN constraints on the cosmological baryon density are reviewed and demonstrate that the bulk of the baryons are dark and also that the bulk of the matter in the universe is nonbaryonic. Comparison of baryonic density arguments from Lyman-alpha clouds, x-ray gas in clusters, and the microwave anisotropy are made. C1 Univ Chicago, Chicago, IL 60637 USA. NASA, Fermilab Astrophys Ctr, Fermilab, Batavia, IL 60510 USA. RP Schramm, DN (reprint author), Univ Chicago, 5640 S Ellis Ave, Chicago, IL 60637 USA. EM dns@oddjob.uchicago.edu NR 83 TC 6 Z9 6 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 USA SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD JAN 6 PY 1998 VL 95 IS 1 BP 42 EP 46 DI 10.1073/pnas.95.1.42 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA YQ846 UT WOS:000071429500010 PM 9419322 ER PT J AU King, WE Schwartz, AJ AF King, WE Schwartz, AJ TI Toward optimization of the grain boundary character distribution in OFE copper SO SCRIPTA MATERIALIA LA English DT Article ID ORIENTATION IMAGING MICROSCOPY; DISTRIBUTION GBCD; INTERGRANULAR CRACKING; DESIGN; TEXTURE; RECRYSTALLIZATION; RESISTANCE C1 Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. RP King, WE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Chem & Mat Sci Directorate, Livermore, CA 94550 USA. NR 18 TC 64 Z9 66 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 6 PY 1998 VL 38 IS 3 BP 449 EP 455 DI 10.1016/S1359-6462(97)00486-7 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA YU649 UT WOS:000071739900014 ER PT J AU McKamey, CG Carmichael, CA Cao, WD Kennedy, RL AF McKamey, CG Carmichael, CA Cao, WD Kennedy, RL TI Creep properties of phosphorus plus boron-modified alloy 718 SO SCRIPTA MATERIALIA LA English DT Article ID HIGH-TEMPERATURE WATER; INTERGRANULAR CRACKING; NI-16CR-9FE C1 Oak Ridge Natl Lab, Div Met & Ceram, Oak Ridge, TN 37831 USA. Allvac, Monroe, NC 28110 USA. RP McKamey, CG (reprint author), Oak Ridge Natl Lab, Div Met & Ceram, POB 2008, Oak Ridge, TN 37831 USA. NR 23 TC 32 Z9 36 U1 1 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6462 J9 SCRIPTA MATER JI Scr. Mater. PD JAN 6 PY 1998 VL 38 IS 3 BP 485 EP 491 DI 10.1016/S1359-6462(97)00476-4 PG 7 WC Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Science & Technology - Other Topics; Materials Science; Metallurgy & Metallurgical Engineering GA YU649 UT WOS:000071739900019 ER PT J AU Michalske, TA Houston, JE AF Michalske, TA Houston, JE TI Dislocation nucleation at nano-scale mechanical contacts SO ACTA MATERIALIA LA English DT Article ID INTERFACIAL FORCE MICROSCOPY; ASSEMBLING MONOLAYER FILMS; INDENTATION EXPERIMENTS; THIN-FILMS; GOLD-FILMS; DEFORMATION; HARDNESS; AU(111); LOAD AB The plastic deformation of metals in highly localized stress fields is critical to macroscopic phenomena such as fracture, surface wear and adhesion where crack tips and surface asperities concentrate the applied stress. Controlled-probe contact techniques can be used to measure forces and displacements on the atomic scale, thereby directly exploring elastic and plastic deformation of solids al the nanometer level. In this study we use interfacial force microscopy to quantitatively examine the nano-scale elastic and plastic response of single crystal Au(111) surfaces using controlled-probe contacts with a range of radii extending down to 500 Angstrom. Our results show that the stress at the plastic threshold increases with decreasing probe-tip radius. We apply a model for dislocation nucleation which reproduces the scaling behavior with tip radius and discuss deficiencies in the model and plausible reasons for the underestimation in quantitative stress values. (C) 1998 Acta Metallurgica Inc. C1 Sandia Natl Labs, Surface & Interface Dept, Albuquerque, NM 87185 USA. RP Michalske, TA (reprint author), Sandia Natl Labs, Surface & Interface Dept, POB 5800, Albuquerque, NM 87185 USA. NR 34 TC 109 Z9 111 U1 2 U2 29 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 5 PY 1998 VL 46 IS 2 BP 391 EP 396 DI 10.1016/S1359-6454(97)00270-X PG 6 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YR995 UT WOS:000071553600002 ER PT J AU Moody, NR Hwang, RQ Venka-Taraman, S Angelo, JE Norwood, DP Gerberich, WW AF Moody, NR Hwang, RQ Venka-Taraman, S Angelo, JE Norwood, DP Gerberich, WW TI Adhesion and fracture of tantalum nitride films SO ACTA MATERIALIA LA English DT Article ID THIN-FILMS; BIMATERIAL INTERFACES; SURFACE-DIFFUSION; INDENTATION; RESISTANCE; STRESS; MICROSCRATCH; DELAMINATION; LOAD; MICROSTRUCTURE AB Indentation fracture and continuous nanoscratch testing were used in this study to determine the effects of compressive residual stresses on the fracture of thin sputter-deposited tantalum nitride films. Some films were tested in the as-deposited condition while others were vacuum annealed at 300 degrees C. The only discernible change in structure was a surface rearrangement of atoms into parallel arrays of striations on the vacuum annealed samples revealing a high compressive residual stress state after deposition. Comparison of results and application of mechanics-based models showed that these stresses had a strong effect on the fracture of the as-deposited films. The models also provided a good measure of the residual stress levels and interfacial strain energy release rates. (C) 1998 Acta Metallurgica Inc. C1 Univ Minnesota, Minneapolis, MN 55455 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Moody, NR (reprint author), Sandia Natl Labs, Livermore, CA 94551 USA. NR 47 TC 40 Z9 40 U1 1 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 5 PY 1998 VL 46 IS 2 BP 585 EP 597 DI 10.1016/S1359-6454(97)00243-7 PG 13 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YR995 UT WOS:000071553600020 ER PT J AU Gilbert, CJ Ritchie, RO AF Gilbert, CJ Ritchie, RO TI On the quantification of bridging tractions during subcritical crack growth under monotonic and cyclic fatigue loading in a grain-bridging silicon carbide ceramic SO ACTA MATERIALIA LA English DT Article ID MECHANICAL WEIGHT FUNCTION; B-C ADDITIONS; OPENING-DISPLACEMENT; CURVE BEHAVIOR; R-CURVES; RESISTANCE; ALUMINA; SPECIMENS; STRESSES; SPINEL AB The mechanisms of cyclic fatigue-crack propagation in a grain-bridging ceramic, namely an in situ toughened, monolithic silicon carbide, is examined. The primary goal is to directly quantify the bridging stresses as a function of cyclic loading. To investigate the effect of the number of loading cycles on the strength of the wake bridging zone, crack-opening profiles of cracks grown at high velocity near the K-c instability (to simulate behavior on the R-curve) and at low velocity near the fatigue threshold (to simulate the cyclically-loaded crack) were measured in situ in the scanning electron microscope at a fixed applied stress intensity. Differences between the measured profiles and those computed for elastic traction-free cracks permit the estimation of the traction distributions. These are then used to simulate resistance curve and fatigue-crack growth rate date. Predictions are found to be in close agreement with experimental measurements on disc-shaped compact-tension specimens. The results provide direct, quantitative evidence that bridging tractions are indeed progressively diminished due to cyclic loading during fatigue-crack propagation in a grain-bridging ceramic. (C) 1998 Acta Metallurgica Inc. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Mat Sci & Mineral Engn, Berkeley, CA 94720 USA. RP Gilbert, CJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Ritchie, Robert/A-8066-2008 OI Ritchie, Robert/0000-0002-0501-6998 NR 38 TC 28 Z9 28 U1 1 U2 6 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 1359-6454 J9 ACTA MATER JI Acta Mater. PD JAN 5 PY 1998 VL 46 IS 2 BP 609 EP 616 DI 10.1016/S1359-6454(97)00248-6 PG 8 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering SC Materials Science; Metallurgy & Metallurgical Engineering GA YR995 UT WOS:000071553600022 ER PT J AU Zouboulis, E Renusch, D Grimsditch, M AF Zouboulis, E Renusch, D Grimsditch, M TI Advantages of ultraviolet Raman scattering for high temperature investigations SO APPLIED PHYSICS LETTERS LA English DT Article ID LASER SOURCE; SPECTROSCOPY AB We show that UV Raman spectroscopy is eminently well suited for the in situ investigation of samples at high temperatures. Using sapphire as a test material, we have recorded Raman spectra from ambient temperature to 1700 K using different excitation wavelengths, both in the visible and near UV region of the spectrum. These spectra show that, because of the very rapid decrease of blackbody radiation in the short wavelength region, Raman spectra recorded in the near UV region of the spectrum are free from the blackbody radiation background, which typically hampers experiments in the visible. With 266 nm exciting radiation, we observe no thermal background even at 1700 K. We foresee that the method will become a powerful tool for in situ investigations of high-temperature materials. (C) 1998 American Institute of Physics. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Natl Tech Univ, Dept Phys, Zografos 15780, Greece. RP Zouboulis, E (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 12 TC 16 Z9 16 U1 3 U2 5 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 5 PY 1998 VL 72 IS 1 BP 1 EP 3 DI 10.1063/1.121437 PG 3 WC Physics, Applied SC Physics GA YP871 UT WOS:000071324400002 ER PT J AU Vanheusden, K Kama, SP Pugh, RD Warren, WL Fleetwood, DM Devine, RAB Edwards, AH AF Vanheusden, K Kama, SP Pugh, RD Warren, WL Fleetwood, DM Devine, RAB Edwards, AH TI Thermally activated electron capture by mobile protons in SiO2 thin films SO APPLIED PHYSICS LETTERS LA English DT Article ID INDUCED INTERFACE STATES; SI/SIO2 INTERFACE; ATOMIC-HYDROGEN; DEFECTS; SILICON; BUILDUP; IRRADIATION; DEPENDENCE; CREATION; OXIDES AB The annihilation of mobile protons in thin SiO2 films by capture of ultraviolet-excited electrons has been analyzed for temperatures between 77 and 500 K. We observe a strong increase in proton annihilation with increasing temperature, and derive an activation energy for electron capture of about 0.2 eV. Based on quantum chemical [(OH)(3)Si](2)-O-H+ cluster calculations, we suggest photoexcitation of electrons from excited vibrational states of the ground electronic (valence band) state to a nearby excited electronic (SiO2 gap) state. It is argued that the latter excitation can result in H-0 formation at elevated temperatures. (C) 1998 American Institute of Physics. C1 USAF, Phillips Lab, Space Mission Technol Div, Kirtland AFB, NM 87117 USA. Sandia Natl Labs, Albuquerque, NM 87185 USA. France Telecom, Ctr Natl Etud Telecommun, F-38243 Meylan, France. Univ N Carolina, Dept Elect Engn, Charlotte, NC 28223 USA. RP Vanheusden, K (reprint author), USAF, Phillips Lab, Space Mission Technol Div, Kirtland AFB, NM 87117 USA. NR 20 TC 23 Z9 24 U1 0 U2 4 PU AMER INST PHYSICS PI WOODBURY PA CIRCULATION FULFILLMENT DIV, 500 SUNNYSIDE BLVD, WOODBURY, NY 11797-2999 USA SN 0003-6951 J9 APPL PHYS LETT JI Appl. Phys. Lett. PD JAN 5 PY 1998 VL 72 IS 1 BP 28 EP 30 DI 10.1063/1.121447 PG 3 WC Physics, Applied SC Physics GA YP871 UT WOS:000071324400011 ER PT J AU Curtis, RA Prausnitz, JM Blanch, HW AF Curtis, RA Prausnitz, JM Blanch, HW TI Protein-protein and protein-salt interactions in aqueous protein solutions containing concentrated electrolytes SO BIOTECHNOLOGY AND BIOENGINEERING LA English DT Article DE proteins; salts; intermolecular interactions; potentials of mean force; precipitation; crystallization ID EGG-WHITE LYSOZYME; PHASE-EQUILIBRIA; CRYSTAL-GROWTH; SERUM-ALBUMIN; SOLUBILITY; CRYSTALLIZATION; THERMODYNAMICS; CHROMATOGRAPHY; PRECIPITATION; PURIFICATION AB Protein-protein and protein-salt interactions have been obtained for ovalbumin in solutions of ammonium sulfate and for lysozyme in solutions of ammonium sulfate, sodium chloride, potassium isothiocyanate, and potassium chloride. The two-body interactions between ovalbumin molecules in concentrated ammonium-sulfate solutions can be described by the DLVO potentials plus a potential that accounts for the decrease in free volume available to the protein due to the presence of the salt ions. The interaction between ovalbumin and ammonium sulfate is unfavorable, reflecting the kosmotropic nature of sulfate anions. Lysozyme-lysozyme interactions cannot be described by the above potentials because anion binding to lysozyme alters these interactions. Lysozyme-isothiocyanate complexes are strongly attractive due to electrostatic interactions resulting from bridging by the isothiocyanate ion. Lysozyme-lysozyme interactions in sulfate solutions are more repulsive than expected, possibly resulting from a larger excluded volume of a lysozyme-sulfate bound complex or perhaps, hydration forces between the lysozyme-sulfate complexes. (C) 1998 John Wiley & Sons, Inc. C1 UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720. UNIV CALIF BERKELEY,LAWRENCE BERKELEY LAB,DIV CHEM SCI,BERKELEY,CA 94720. NR 56 TC 160 Z9 162 U1 3 U2 38 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0006-3592 J9 BIOTECHNOL BIOENG JI Biotechnol. Bioeng. PD JAN 5 PY 1998 VL 57 IS 1 BP 11 EP 21 DI 10.1002/(SICI)1097-0290(19980105)57:1<11::AID-BIT2>3.0.CO;2-Y PG 11 WC Biotechnology & Applied Microbiology SC Biotechnology & Applied Microbiology GA YH990 UT WOS:A1998YH99000002 PM 10099173 ER PT J AU Kendrick, B AF Kendrick, B TI The effects of pseudomagnetic fields in molecular spectra and scattering (vol 64, pg 581, 1997) SO INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY LA English DT Correction, Addition RP Kendrick, B (reprint author), LOS ALAMOS NATL LAB,THEORET DIV T12 MSB268,POB 1663,LOS ALAMOS,NM 87545, USA. NR 3 TC 5 Z9 5 U1 0 U2 1 PU JOHN WILEY & SONS INC PI NEW YORK PA 605 THIRD AVE, NEW YORK, NY 10158-0012 SN 0020-7608 J9 INT J QUANTUM CHEM JI Int. J. Quantum Chem. PD JAN 5 PY 1998 VL 66 IS 1 BP 111 EP 111 DI 10.1002/(SICI)1097-461X(1998)66:1<111::AID-QUA11>3.0.CO;2-C PG 1 WC Chemistry, Physical; Mathematics, Interdisciplinary Applications; Physics, Atomic, Molecular & Chemical SC Chemistry; Mathematics; Physics GA YH540 UT WOS:A1998YH54000009 ER PT J AU Conzett, HE AF Conzett, HE TI The vanishing analyzing powers in electron-proton elastic scattering; symmetries and dynamics SO NUCLEAR PHYSICS A LA English DT Article DE electron-proton scattering; role of P and T symmetries; hermiticity; and helicity conservation in vanishing of proton analyzing power ID TIME-REVERSAL INVARIANCE; TESTS AB In high energy electron-proton elastic scattering the two parity-conserving analyzing powers vanish in the one-photon-exchange approximation. The electron analyzing-power vanishes from electron helicity-conservation, but the underlying reason(s) for the vanishing of the proton analyzing-power is (are) not clear. Therefore, a more detailed examination of this question has been made and is reported here. It is then noted that the proton analyzing-power is an optimum experimental observable for the determination of higher order contributions to this basic electron-nucleon electromagnetic interaction. (C) 1998 Elsevier Science B.V. C1 Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Conzett, HE (reprint author), Lawrence Berkeley Lab, Div Nucl Sci, Bldg 88-111,1 Cyclotron Rd, Berkeley, CA 94720 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 0375-9474 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 5 PY 1998 VL 628 IS 1 BP 81 EP 86 DI 10.1016/S0375-9474(97)00593-9 PG 6 WC Physics, Nuclear SC Physics GA YZ190 UT WOS:000072229300005 ER PT J AU Burakovsky, L Goldman, T AF Burakovsky, L Goldman, T TI Towards resolution of the scalar meson nonet enigma: Gell-Mann-Okubo revisited SO NUCLEAR PHYSICS A LA English DT Article DE pseudoscalar mesons; scalar mesons; Nambu-Jona-Lasinio; instantons ID JONA-LASINIO MODEL; MIXING ANGLE; 450 GEV/C; RESONANCE; NARROW; DECAY; NAMBU; ETA; ANNIHILATION; GLUEBALL AB The new SU(3) nonet mass formula 2M(2)(s (s) over bar) + 3M(2)(n (n) over bar, I = 1) = 4M(2)(s (n) over bar) + M-2(n (n) over bar, I = 0) (n = u, d), obtained in our previous paper by using Regge phenomenology, is rederived for the pseudoscalar and scalar mesons in the Nambu-Jona-Lasinio model with instanton-induced interaction and applied to the problem of the correct qq assignment for the scalar meson nonet. The results strongly favor the masses of the scalar isoscalar mostly octet and mostly singlet states in the vicinity of 1.45 and 1.1 GeV, respectively. (C) 1998 Elsevier Science B.V. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Burakovsky, L (reprint author), Los Alamos Natl Lab, Div Theoret, MS B285, Los Alamos, NM 87545 USA. EM burakov@pion.lanl.gov; goldman@t5.lanl.gov NR 58 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9474 EI 1873-1554 J9 NUCL PHYS A JI Nucl. Phys. A PD JAN 5 PY 1998 VL 628 IS 1 BP 87 EP 100 DI 10.1016/S0375-9474(97)00611-8 PG 14 WC Physics, Nuclear SC Physics GA YZ190 UT WOS:000072229300006 ER PT J AU Arkani-Hamed, N March-Russell, J Murayama, H AF Arkani-Hamed, N March-Russell, J Murayama, H TI Building models of gauge-mediated supersymmetry breaking without a messenger sector SO NUCLEAR PHYSICS B LA English DT Article ID LINEAR E(+)E(-) COLLIDERS; MODULI SPACES; MECHANISM; SCALE AB We propose a general scheme for constructing models in which the Standard Model (SM) gauge interactions are the mediators of supersymmetry breaking to the fields in the supersymmetric SM, but where the SM gauge groups couple directly to the sector which breaks supersymmetry dynamically. Despite the direct coupling, the models preserve perturbative unification of the SM gauge coupling constants. Furthermore, the supergravity contributions to the squark and slepton masses can be naturally small, typically being much less than 1% of the gauge-mediated (GM) contributions. Both of these goals can be achieved without need of a fine-tuning or a very small coupling constant. This scheme requires run-away directions at the renormalizable level which are only lifted by non-renormalizable terms in the superpotential. To study the proposed scheme in practice, we develop a modified class of models based on SU(N) x SU(N - 1) which allows us to gauge an SU(N - 2) global symmetry. However, we point out a new problem which can exist in models where the dynamical supersymmetry breaking sector and the ordinary sector are directly coupled - the two-loop renormalization group has contributions which can induce negative (mass)(2) for the squarks and sleptons. We clarify the origin of the problem and argue that it is likely to be surmountable. We give a recipe for a successful model. (C) 1998 Published by Elsevier Science B.V. C1 Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Inst Adv Study, Sch Nat Sci, Princeton, NJ 08540 USA. RP Univ Calif Berkeley, Ernest Orlando Lawrence Berkeley Natl Lab, Theoret Phys Grp, Berkeley, CA 94720 USA. RI Murayama, Hitoshi/A-4286-2011 NR 62 TC 77 Z9 77 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0550-3213 EI 1873-1562 J9 NUCL PHYS B JI Nucl. Phys. B PD JAN 5 PY 1998 VL 509 IS 1-2 BP 3 EP 32 DI 10.1016/S0550-3213(97)00573-7 PG 30 WC Physics, Particles & Fields SC Physics GA YM601 UT WOS:000071081100001 ER PT J AU Shan, XW He, XY AF Shan, XW He, XY TI Discretization of the velocity space in the solution of the Boltzmann equation SO PHYSICAL REVIEW LETTERS LA English DT Article ID NAVIER-STOKES EQUATION; LATTICE AB We point out an equivalence between the discrete velocity method of solving the Boltzmann equation, of which the lattice Boltzmann equation method is a special example, and the approximations to the Boltzmann equation by a Hermite polynomial expansion. Discretizing the Boltzmann equation with a Bhatnagar-Gross-Krook collision term at the velocities that correspond to the nodes of a Hermite quadrature is shown to be equivalent to truncating the Hermite expansion of the distribution function to the corresponding order. The truncated part of the distribution has no contribution to the moments of low orders and is negligible at small Mach numbers. C1 Univ Calif Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, Los Alamos, NM 87545 USA. USAF, Res Lab, GPOF, PL, Hanscom AFB, MA 01731 USA. RP Shan, XW (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret, Complex Syst Grp, MS-B213, Los Alamos, NM 87545 USA. RI Shan, Xiaowen/H-2836-2013 OI Shan, Xiaowen/0000-0002-6350-9248 NR 17 TC 213 Z9 216 U1 2 U2 27 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 5 PY 1998 VL 80 IS 1 BP 65 EP 68 DI 10.1103/PhysRevLett.80.65 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ289 UT WOS:000071370400017 ER PT J AU Barov, N Conde, ME Gai, W Rosenzweig, JB AF Barov, N Conde, ME Gai, W Rosenzweig, JB TI Propagation of short electron pulses in a plasma channel SO PHYSICAL REVIEW LETTERS LA English DT Article ID ION-FOCUSED REGIME; BEAM; ACCELERATION; LENS AB We report the near-steady state propagation over long distance of a 25 psec, tightly focused relativistic electron beam which creates, by radial ejection of plasma electrons, a focusing ion channel in a plasma of electron density smaller than the beam. A dense beam core, close in radius to the injected beam, which was nearly matched to the ion focusing strength, is observed at the plasma exit. Time-resolved imaging confirms that this core is situated in the trailing half of the beam, as predicted by analytical and computer models. We discuss the impact of these results on plasma wake field acceleration schemes. C1 Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA. Argonne Natl Lab, Div High Energy Phys, Argonne, IL 60439 USA. RP Univ Calif Los Angeles, Dept Phys & Astron, 405 Hilgard Ave, Los Angeles, CA 90095 USA. NR 18 TC 39 Z9 39 U1 0 U2 2 PU AMER PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 EI 1079-7114 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 5 PY 1998 VL 80 IS 1 BP 81 EP 84 DI 10.1103/PhysRevLett.80.81 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ289 UT WOS:000071370400021 ER PT J AU DeWilde, Y Miyakawa, N Guptasarma, P Iavarone, M Ozyuzer, L Zasadzinski, JF Romano, P Hinks, DG Kendziora, C Crabtree, GW Gray, KE AF DeWilde, Y Miyakawa, N Guptasarma, P Iavarone, M Ozyuzer, L Zasadzinski, JF Romano, P Hinks, DG Kendziora, C Crabtree, GW Gray, KE TI Unusual strong-coupling effects in the tunneling spectroscopy of optimally doped and overdoped Bi2Sr2CaCu2O8+delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID ANGLE-RESOLVED PHOTOEMISSION; STATES; SUPERCONDUCTORS; DENSITY; ANISOTROPY; GAP AB Tunneling spectroscopy measurements are reported on single crystals of Bi2Sr2CaCu2O8+delta using vacuum tunneling and point-contact methods. A reproducible dip feature in the tunneling conductance is found near /eV/ = 2 Delta, observed for both voltage polarities in the best resolved spectra. With overdoping the position of the dip continues to scale with a, and its magnitude decreases as a decreases. These results indicate that the dip feature arises from a strong-coupling effect whereby the quasiparticle lifetime is decreased at a characteristic energy of similar to 2 Delta, consistent with an electron-electron pairing interaction. C1 Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. Sci Univ Tokyo, Dept Appl Phys, Shinjuku Ku, Tokyo 162, Japan. IIT, Chicago, IL 60616 USA. USN, Res Lab, Washington, DC 20375 USA. RP DeWilde, Y (reprint author), Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. RI Iavarone, Maria/C-3628-2008; Ozyuzer, Lutfi/H-3142-2011; OI De Wilde, Yannick/0000-0002-5973-1460 NR 23 TC 166 Z9 167 U1 1 U2 4 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 5 PY 1998 VL 80 IS 1 BP 153 EP 156 DI 10.1103/PhysRevLett.80.153 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ289 UT WOS:000071370400039 ER PT J AU Miyakawa, N Guptasarma, P Zasadzinski, JF Hinks, DG Gray, KE AF Miyakawa, N Guptasarma, P Zasadzinski, JF Hinks, DG Gray, KE TI Strong dependence of the superconducting gap on oxygen doping from tunneling measurements on Bi2Sr2CaCu2O8-delta SO PHYSICAL REVIEW LETTERS LA English DT Article ID T-C SUPERCONDUCTORS; ELECTRONIC SPECIFIC-HEAT; NORMAL-STATE; SPECTROSCOPY; CONDUCTANCE AB Tunneling measurements are reported for break junctions on Bi2Sr2CaCu2O8-delta Single crystals with various oxygen concentrations. Superconducting energy gaps a are observed in the underdoped samples which are considerably larger (similar to 30%) than found in optimal doped crystals. The trend of decreasing Delta and 2 Delta/kT(c), with increasing hole doping is continued into the overdoped region. Thus the superconducting gap and strong-coupling ratio change monotonically and dramatically over a narrow doping region where T-c, exhibits a maximum. C1 Argonne Natl Lab, Div Mat Sci, Argonne, IL 60439 USA. Argonne Natl Lab, Sci & Technol Ctr Supercond, Argonne, IL 60439 USA. Sci Univ Tokyo, Dept Appl Phys, Shinjuku Ku, Tokyo 162, Japan. IIT, Chicago, IL 60616 USA. RP Miyakawa, N (reprint author), Argonne Natl Lab, Div Mat Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 24 TC 264 Z9 264 U1 0 U2 5 PU AMERICAN PHYSICAL SOC PI COLLEGE PK PA ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA SN 0031-9007 J9 PHYS REV LETT JI Phys. Rev. Lett. PD JAN 5 PY 1998 VL 80 IS 1 BP 157 EP 160 DI 10.1103/PhysRevLett.80.157 PG 4 WC Physics, Multidisciplinary SC Physics GA YQ289 UT WOS:000071370400040 ER PT J AU Nieto, MM Truax, DR AF Nieto, MM Truax, DR TI Reply to "Generating functions for Hermite polynomials of arbitrary order" by Fernandez SO PHYSICS LETTERS A LA English DT Editorial Material AB The results in the comment by Fernandez [Phys. Lett, A 237 (1998) 189] are placed on a more general mathematical foundation. (C) 1998 Published by Elsevier Science B.V. C1 Univ Calif Los Alamos Natl Lab, Theoret Div MSB285, Los Alamos, NM 87545 USA. Univ Calgary, Dept Chem, Calgary, AB T2N 1N4, Canada. RP Nieto, MM (reprint author), Univ Calif Los Alamos Natl Lab, Theoret Div MSB285, POB 1663, Los Alamos, NM 87545 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0375-9601 J9 PHYS LETT A JI Phys. Lett. A PD JAN 5 PY 1998 VL 237 IS 3 BP 192 EP 193 DI 10.1016/S0375-9601(97)00854-2 PG 2 WC Physics, Multidisciplinary SC Physics GA YQ830 UT WOS:000071427400017 ER PT J AU Wang, JH Lim, K Smolyar, A Teng, MK Liu, JH Tse, AGD Liu, J Hussey, RE Chishti, Y Thomson, CT Sweet, RM Nathenson, SG Chang, HC Sacchettini, JC Reinherz, EL AF Wang, JH Lim, K Smolyar, A Teng, MK Liu, JH Tse, AGD Liu, J Hussey, RE Chishti, Y Thomson, CT Sweet, RM Nathenson, SG Chang, HC Sacchettini, JC Reinherz, EL TI Atomic structure of an alpha beta T cell receptor (TCR) heterodimer in complex with an anti-TCR Fab fragment derived from a mitogenic antibody SO EMBO JOURNAL LA English DT Review DE crystallography; immune receptors; quaternary structure; signal transduction ID MAJOR HISTOCOMPATIBILITY COMPLEX; ELECTRON-DENSITY MAPS; CLASS-I H-2K(B); CRYSTAL-STRUCTURE; MONOCLONAL-ANTIBODY; LYMPHOCYTES-T; CD3 COMPLEX; T3-MOLECULAR COMPLEX; PEPTIDE VARIABILITY; SIGNAL TRANSDUCTION AB Each T cell receptor (TCR) recognizes a peptide antigen bound to a major histocompatibility complex (MHC) molecule via a clonotypic alpha beta heterodimeric structure (Ti) non-covalently associated with the monomorphic CD3 signaling components, A crystal structure of an alpha beta TCR-anti-TCR Fab complex: shows an Fab fragment derived from the H57 monoclonal antibody (mAb), interacting with the elongated FG loop of the C beta domain, situated beneath the V beta domain, This loop, along with the partially exposed ABED beta sheet of C beta, and glycans attached to both C beta and C alpha domains, forms a cavity of sufficient size to accommodate a single non-glycosylated Ig domain such as the CD3 epsilon ectodomain, That this asymmetrically localized site is embedded within the rigid constant domain module has implications for the mechanism of signal transduction in both TCR and pre-TCR complexes. Furthermore, quaternary structures of TCRs vary significantly even when they bind the same MHC molecule, as manifested by a unique twisting of the V module relative to the C module. C1 Harvard Univ, Sch Med, Dana Farber Canc Inst, Immunobiol Lab, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Med, Boston, MA 02115 USA. Harvard Univ, Sch Med, Dept Pediat, Boston, MA 02115 USA. Texas A&M Univ, Dept Biochem & Biophys, College Stn, TX 77843 USA. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Yeshiva Univ Albert Einstein Coll Med, Dept Microbiol & Immunol, Bronx, NY 10461 USA. RP Reinherz, EL (reprint author), Univ Sci & Technol China, Dept Biol, Hefei 230026, Peoples R China. NR 108 TC 150 Z9 151 U1 0 U2 4 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0261-4189 J9 EMBO J JI Embo J. PD JAN 2 PY 1998 VL 17 IS 1 BP 10 EP 26 DI 10.1093/emboj/17.1.10 PG 17 WC Biochemistry & Molecular Biology; Cell Biology SC Biochemistry & Molecular Biology; Cell Biology GA YU347 UT WOS:000071708000002 PM 9427737 ER PT B AU Pace, JC Nasstrom, JS AF Pace, JC Nasstrom, JS GP AMER METEOROL SOC AMER METEOROL SOC TI Evaluation of ARAC's models using the ETEX data set SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94551 USA. RP Pace, JC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, POB 808,L-103, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 40 EP 43 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100009 ER PT B AU Pace, JC AF Pace, JC GP AMER METEOROL SOC AMER METEOROL SOC TI Description of ARAC's real-time modeling support to the Mars Pathfinder and Cassini missions SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94551 USA. RP Pace, JC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, POB 808,L-103, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 44 EP 48 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100010 ER PT B AU Shannon, JD AF Shannon, JD GP AMER METEOROL SOC AMER METEOROL SOC TI Expanding the horizons of the Visibility Assessment Scoping Model (VASM) SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Argonne Natl Lab, Div Environm Sci, Argonne, IL 60439 USA. RP Shannon, JD (reprint author), Argonne Natl Lab, Div Environm Sci, Bldg 203, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 100 EP 104 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100023 ER PT B AU Brown, MJ Muller, C Stretz, P AF Brown, MJ Muller, C Stretz, P GP AMER METEOROL SOC AMER METEOROL SOC TI Exposure estimates using urban plume dispersion and traffic microsimulation models SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Los Alamos Natl Lab, Energy & Environm Anal Grp, Los Alamos, NM 87545 USA. RP Brown, MJ (reprint author), Univ Calif Los Alamos Natl Lab, Energy & Environm Anal Grp, TSA-4,MS F604, Los Alamos, NM 87545 USA. NR 0 TC 1 Z9 1 U1 0 U2 2 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 140 EP 143 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100032 ER PT B AU Shannon, JD AF Shannon, JD GP AMER METEOROL SOC AMER METEOROL SOC TI Modeling air pollution in the Tracking and Analysis Framework (TAF) SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Shannon, JD (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 203, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 158 EP 162 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100036 ER PT B AU Berkowitz, CM Fast, JD AF Berkowitz, CM Fast, JD GP AMER METEOROL SOC AMER METEOROL SOC TI A preliminary analysis of the effect of boundary layer mixing on elevated photochemical plumes over Connecticut SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Battelle Mem Inst, Pacific NW Labs, Atmospher Sci Grp, Richland, WA 99352 USA. RP Berkowitz, CM (reprint author), Battelle Mem Inst, Pacific NW Labs, Atmospher Sci Grp, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 192 EP 195 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100043 ER PT B AU Chan, ST AF Chan, ST GP AMER METEOROL SOC AMER METEOROL SOC TI A three-dimensional model for simulating atmospheric dispersion of heavy-gases over complex terrain SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Chan, ST (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-103, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 220 EP 222 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100050 ER PT B AU Bowen, BM Baars, JA Stone, JA AF Bowen, BM Baars, JA Stone, JA GP AMER METEOROL SOC AMER METEOROL SOC TI Nocturnal wind direction shear and its potential impact on pollutant transport SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, ARAC, Livermore, CA 94550 USA. RP Bowen, BM (reprint author), Univ Calif Lawrence Livermore Natl Lab, ARAC, L-103,POB 808, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 236 EP 241 PG 6 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100054 ER PT B AU Sugiyama, G Chan, ST AF Sugiyama, G Chan, ST GP AMER METEOROL SOC AMER METEOROL SOC TI A new meteorological data assimilation model for real-time emergency response SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Sugiyama, G (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-103,POB 808, Livermore, CA 94550 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 285 EP 289 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100065 ER PT B AU Lee, RL Albritton, JR Foster, K Leone, JM Sugiyama, G AF Lee, RL Albritton, JR Foster, K Leone, JM Sugiyama, G GP AMER METEOROL SOC AMER METEOROL SOC TI ARAC-3, a new modeling system for real-time responses and assessments of atmospheric releases SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Lee, RL (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 290 EP 293 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100066 ER PT B AU Pace, JC Albritton, JR Baskett, RL Zhang, XJ Masonjones, MC Moussa, NA Overbeck, K Parks, CR Evans, RJ AF Pace, JC Albritton, JR Baskett, RL Zhang, XJ Masonjones, MC Moussa, NA Overbeck, K Parks, CR Evans, RJ GP AMER METEOROL SOC AMER METEOROL SOC TI Modeling the 17 January 1997 Delta-II explosion by ARAC, ADORA, and REEDM SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94551 USA. RP Pace, JC (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, L-103,POB 808, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 294 EP 301 PG 8 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100067 ER PT B AU Zhong, S Doran, JC Fast, JD AF Zhong, S Doran, JC Fast, JD GP AMER METEOROL SOC AMER METEOROL SOC TI The effect of re-entrainment on surface pollutant concentration in the Mexico City Basin SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Pacific NW Natl Lab, Richland, WA USA. RP Zhong, S (reprint author), MSIN, POB 999,K9-30, Richland, WA 99352 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 372 EP 376 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100083 ER PT B AU Fast, JD AF Fast, JD GP AMER METEOROL SOC AMER METEOROL SOC TI The impact of thermally-driven circulations on inhomogeneous ozone concentrations within the Mexico City Basin SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Fast, JD (reprint author), Pacific NW Natl Lab, POB 999,K9-30, Richland, WA 99352 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 377 EP 381 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100084 ER PT B AU Bian, X Whiteman, CD Iglesias, GS Garcia, EW AF Bian, X Whiteman, CD Iglesias, GS Garcia, EW GP AMER METEOROL SOC AMER METEOROL SOC TI Climatological analyses of air pollution in the Mexico Basin SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Pacific NW Natl Lab, Richland, WA USA. RP Bian, X (reprint author), Battelle NW Labs, K9-30,POB 999, Richland, WA 99352 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 382 EP 386 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100085 ER PT B AU Nasstrom, JS Ermak, DL AF Nasstrom, JS Ermak, DL GP AMER METEOROL SOC AMER METEOROL SOC TI Langevin equation modeling of convective boundary layer dispersion assuming homogeneous, skewed turbulence SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nasstrom, JS (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-103,POB 806, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 555 EP 559 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100123 ER PT B AU Coulter, RL Klazura, J Lesht, BM Shannon, JD Sisterson, DL Wesely, ML AF Coulter, RL Klazura, J Lesht, BM Shannon, JD Sisterson, DL Wesely, ML GP AMER METEOROL SOC AMER METEOROL SOC TI Using the ABLE facility to observe urbanization effects on planetary boundary layer processes SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Meeting Abstract CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Coulter, RL (reprint author), Argonne Natl Lab, Div Environm Res, Bldg 203, Argonne, IL 60439 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP J76 EP J79 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100148 ER PT B AU Doran, JC Coulter, RL King, CW Lee, JT Sosa, G AF Doran, JC Coulter, RL King, CW Lee, JT Sosa, G GP AMER METEOROL SOC AMER METEOROL SOC TI Wind patterns affecting pollutant transport in Mexico City SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Pacific NW Labs, Richland, WA 99352 USA. RP Doran, JC (reprint author), Pacific NW Labs, POB 999,MSIN K9-30, Richland, WA 99352 USA. RI Sosa, Gustavo/F-3912-2015 OI Sosa, Gustavo/0000-0002-4980-3491 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP J33 EP J37 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100139 ER PT B AU Fast, JD AF Fast, JD GP AMER METEOROL SOC AMER METEOROL SOC TI Observational requirements for describing circulations within the Mexico City basin using four-dimensional data assimilation SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Meeting Abstract CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Pacific NW Labs, Richland, WA 99352 USA. RP Fast, JD (reprint author), Pacific NW Labs, POB 999,K9-30, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP J71 EP J75 PG 5 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100147 ER PT B AU Gaffney, JS Marley, NA Drayton, PJ AF Gaffney, JS Marley, NA Drayton, PJ GP AMER METEOROL SOC AMER METEOROL SOC TI Aircraft measurements of nitrogen dioxide and peroxyacyl nitrates using luminol chemiluminescence with fast capillary gas chromatography SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Gaffney, JS (reprint author), Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP J45 EP J47 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100142 ER PT B AU Marley, NA Gaffney, JS Cunningham, MM AF Marley, NA Gaffney, JS Cunningham, MM GP AMER METEOROL SOC AMER METEOROL SOC TI Ozone chemiluminescent detection of olefins: Potential applications for real-time measurements of natural hydrocarbon emissions SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Argonne Natl Lab, Div Environm Res, Argonne, IL 60439 USA. RP Marley, NA (reprint author), Argonne Natl Lab, Div Environm Res, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP J42 EP J44 PG 3 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100141 ER PT B AU Shaw, WJ Spicer, CW Kenny, DV AF Shaw, WJ Spicer, CW Kenny, DV GP AMER METEOROL SOC AMER METEOROL SOC TI Evaluation of a tandem mass spectrometer for measuring eddy correlation fluxes of trace gases SO 10TH JOINT CONFERENCE ON THE APPLICATIONS OF AIR POLLUTION METEOROLOGY WITH THE A&WMA LA English DT Proceedings Paper CT 10th Joint Conference on the Applications of Air Pollution Meteorology with the A&WMA / American-Meteorological-Society CY JAN 11-16, 1998 CL PHOENIX, AZ SP Air & Waste Management Assoc, Amer Meteorol Soc C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Shaw, WJ (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999,MS K9-30, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP J38 EP J41 PG 4 WC Environmental Sciences; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences GA BL92P UT WOS:000077162100140 ER PT B AU Albritton, JR Kong, J Lee, RL Hodur, R Lieu, CS AF Albritton, JR Kong, J Lee, RL Hodur, R Lieu, CS GP AMS AMS TI Simulations of the march 1996 storm in the San Francisco Bay Area SO 12TH CONFERENCE ON NUMERICAL WEATHER PREDICTION LA English DT Proceedings Paper CT 12th Conference on Numerical Weather Prediction CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc (AMS) AB The San Francisco/Monterey Bay Area in California experienced a severe weather, precipitation, event in early March of 1996. A series of waves moved across the region from the NW from March 10 through 12th, delivering successively heavier rains. Subsequently the system moved to central and Southern California where still more severe weather developed on March 13th; others have begun to study this final phase of the storm. The case of interest is described and illustrated qualitatively at an internet site accessible from the San Francisco Bay Area National Weather Service's main site, http://www.nws.mbay.net/home.html, or directly at http://nimbo.wrh.noaa.gov/Monterey/bami/bami.html, authored by Scott Archer and Dave Reynolds. C1 Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94550 USA. RP Albritton, JR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 63 EP 64 PG 2 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM02Q UT WOS:000077436900021 ER PT B AU Leach, MJ Kong, J AF Leach, MJ Kong, J GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI Scale interaction in a California precipitation event SO 16TH CONFERENCE ON WEATHER ANALYSIS AND FORECASTING / SYMPOSIUM ON THE RESEARCH FOCI OF THE U.S. WEATHER RESEARCH PROGRAM LA English DT Proceedings Paper CT 16th Conference on Weather Analysis and Forecasting / Symposium on the Research Foci of the US Weather Research Program CY JAN 11-16, 1998 CL PHOENIX, AZ SP Amer Meteorol Soc C1 Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, Livermore, CA 94550 USA. RP Leach, MJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, Div Atmospher Sci, L-103, Livermore, CA 94550 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 270 EP 272 PG 3 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BL92Q UT WOS:000077162300093 ER PT B AU Paisner, JA Murray, JR AF Paisner, JA Murray, JR GP IEEE IEEE IEEE TI The National Ignition Facility for inertial confinement fusion SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The National Ignition Facility for inertial confinement fusion will contain a 1.8 MJ, 500 TW frequency-tripled neodymium glass laser system that will. be used to explore fusion ignition and other problems in the physics of high temperature and density. We describe the facility briefly. The NIF is scheduled to be completed in 2003. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Paisner, JA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 57 EP 62 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300008 ER PT B AU von Halle, A AF von Halle, A CA TFTR Grp GP IEEE IEEE IEEE TI Final operations of the tokamak fusion test reactor (TFTR) SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB In April of 1997, The TFTR completed it's final operating period bringing to a close a highly successful phase of research in plasma science. The TFTR produced over 80,000 high power plasmas since 1982 with the objectives of studying the plasma physics of large tokamaks, gaining experience in the solution of engineering problems associated with large fusion systems, and demonstrating fusion energy production from the burning, on a pulsed basis, of deuterium and tritium in a magnetically confined toroidal plasma system. In 1993, TFTR became the first magnetic fusion device to study plasmas using nearly equal concentrations of deuterium and tritium. Since that time, over 1000 D-T experimental shots and over 23,000 D-D shots have been carried out demonstrating new regimes of plasma confinement, proof of alpha heating, and reactor level fusion power densities by producing a plasma which yielded over 10MW of fusion power at a corresponding central fusion power density of similar to 2.8MWm(-3). The TFTR technical systems routinely operated at or beyond the original design criteria throughout the period, maintaining an impressive machine availability of >85%, and continued to do so through the final night of operations when a plasma with a record 7.7MJ of stored energy was attained. Safe operation of the TFTR systems in D-T has been demonstrated, with over 950kCi of tritium processed within the constraints of a 50kCi site limit and a 20kCi machine limit. The Tritium Purification System "closed the loop" on the TFTR fuel cycle during the final operating campaign, processing >50kCi of tritium at >98% purity back to the Tritium Storage and Delivery System U-Beds for further use on TFTR experiments. This paper describes the experimental results of TFTR along with the technical systems and operating routines that provided the backbone of the TFTR experimental program. Discussed are the upgrades made to the TFTR device in preparation for the final operating campaign and the present plans for the shutdown and safing of the facility. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP von Halle, A (reprint author), Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 2 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 65 EP 69 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300009 ER PT B AU Piet, SJ Bosia, G Costley, A diPietro, E Dilling, DA Johnson, G Kataoka, Y Makowsi, MA Schleicher, R Taylor, N Walker, C Wykes, M AF Piet, SJ Bosia, G Costley, A diPietro, E Dilling, DA Johnson, G Kataoka, Y Makowsi, MA Schleicher, R Taylor, N Walker, C Wykes, M GP IEEE IEEE IEEE TI Implementation of the ITER radionuclide confinement function SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The ITER confinement is tailored to ITER technological constraints and ITER radiological and chemical hazards, while meeting the consensus environmental release limits adopted by the project. This paper summarizes the ITER confinement functional requirements, describes the confinement strategy for the ITER tokamak, and shows how the design meets the objectives, All radionuclide sources are confined by at least two barriers. The first barrier for the ITER plasma and in-vessel deposits is the vacuum vessel (VV) and the er-vessel portions of the primary heat transfer system (PHTS) of the plasma facing components. The second barrier starts with the cryostat vessel (CV! and is extended to include the heat transfer vaults, Thus, two critical components are high quality vacuum vessels, which must be intact for the machine to operate independent of safety considerations. Features to prevent or limit releases via various penetrations of the VV are tailored to the characteristics of the potential hazards associated with each system, as in a chemical plant. This strategy includes first and second barriers in various heating and current drive systems interfacing with the plasma. The primary heat transfer coolant is contained by the cooling systems and by the PI-ITS vaults that form the second barrier. Outside the second barrier, some volumes are assigned confinement-related functions and are equipped with heating, ventilation, and air-conditioning (HVAC) systems which treat potential releases. These features work together to assure that the potential impact on public health and safety is within acceptable limits for all credible challenging events, The paper also includes limited information on the confinement of sources during maintenance, in the tritium plant, and in the hot cell building. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Piet, SJ (reprint author), Idaho Natl Engn & Environm Lab, POB 1625,2351 North Blvd,M-S 2214, Idaho Falls, ID 83415 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 129 EP 132 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300021 ER PT B AU Latkowski, JF Phillips, TW AF Latkowski, JF Phillips, TW GP IEEE IEEE IEEE TI Monte Carlo prompt dose calculations for the National Ignition Facility SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB During peak operation, the National Ignition Facility (NIF) will conduct as many as 600 experiments per year and attain deuterium-tritium fusion yields as high as 1200 MJ/yr, The radiation effective dose equivalent (EDE) to workers is limited to an average of 0.3 mSv/yr (30 mrem/yr) in occupied areas of the facility. Laboratory personnel located outside the facility will receive EDEs less than or equal to 0.5 mSv/yr (less than or equal to 50 mrem/yr). The total annual occupational EDE for the facility will be maintained at I 0.1 person-Sv/yr (less than or equal to 10 person-rem/yr). To ensure that prompt EDEs meet these limits, three-dimensional Monte Carlo calculations have been completed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Latkowski, JF (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave,L-481, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 149 EP 152 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300026 ER PT B AU Smolik, GR McCarthy, KA Carmack, WJ Coates, K AF Smolik, GR McCarthy, KA Carmack, WJ Coates, K GP IEEE IEEE IEEE TI Mobilization from austenitic stainless steel in air and steam: Recent tests, compilation of data from tests to date, and resulting dose calculations SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB A failure in the vacuum plasma chamber of a fusion reactor could result in the intrusion of air or steam causing oxidation of activated materials comprising plasma facing and structural components. Brides formed may then be mobilized by mechanisms involving either volatilized or spalled oxides. We have measured the mobilization of various elements from austenitic stainless steels, which is a candidate structural material, using transpiration test methods. This paper compiles all data for this type of alloy from our experimental studies performed from 1983 to 1996 and presents dose calculations resulting from the updated database. C1 Idaho Natl Engn & Environm Lab, LMITCO, Idaho Falls, ID 83415 USA. RP Smolik, GR (reprint author), Idaho Natl Engn & Environm Lab, LMITCO, POB 1625, Idaho Falls, ID 83415 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 161 EP 166 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300029 ER PT B AU Piet, SJ Costley, A Federici, G Heckendorn, F Little, R AF Piet, SJ Costley, A Federici, G Heckendorn, F Little, R GP IEEE IEEE IEEE TI ITER tokamak dust - Limits, production, removal surveying SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Some tokamak dust will exist inside the ITER Vacuum Vessel as a result of routine sputtering, disruptions, and possibly maintenance-related activities. The three plasma-facing materials (beryllium, carbon, tungsten) will give rise to a dust mixture with radiological, chemically toxic, and chemically reactive hazards. The project has evolved an approach to ensuring that the public is protected via confinement, limiting chemical reactions, and limiting the dust Inventory, This paper provides an overview of the dust safety limits, production, removal, and surveying methods. C1 Idaho Natl Engn & Environm Lab, Idaho Falls, ID 83415 USA. RP Piet, SJ (reprint author), Idaho Natl Engn & Environm Lab, POB 1625,2351 N Blvd,MS 2214, Idaho Falls, ID 83415 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 167 EP 170 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300030 ER PT B AU Smolik, GR Anderl, RA Pawelko, RJ Carmack, WJ Hembree, PB Oates, MA AF Smolik, GR Anderl, RA Pawelko, RJ Carmack, WJ Hembree, PB Oates, MA GP IEEE IEEE IEEE TI BET surface area measurements of materials for fusion safety studies SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The reaction of air or steam with plasma facing materials and tokamak dust is a concern during an accident involving a breach in the vacuum plasma chamber of a fusion reactor. Hydrogen generated from steam reactions must be maintained below explosive concentrations. An important parameter influencing reaction rates is the specific surface area (SSA) of a material. We present the capabilities and background that we have obtained using the BET gas adsorption method on various fusion relevant materials. BET data are useful in developing correlations with steam reaction rates and characterizing irradiated beryllium and dust collected from tokamaks. C1 Idaho Natl Engn & Environm Lab, LMITCO, Idaho Falls, ID 83415 USA. RP Smolik, GR (reprint author), Idaho Natl Engn & Environm Lab, LMITCO, POB 1625, Idaho Falls, ID 83415 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 183 EP 187 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300034 ER PT B AU Neumeyer, C Heitzenroeder, P Chrzanowski, J Nelson, B Spitzer, J Wilson, R Dudek, L Kaita, R Ramakrishnan, S Bashore, D Perry, E AF Neumeyer, C Heitzenroeder, P Chrzanowski, J Nelson, B Spitzer, J Wilson, R Dudek, L Kaita, R Ramakrishnan, S Bashore, D Perry, E CA NSTX Team GP IEEE IEEE IEEE TI Engineering overview of the national spherical torus experiment (NSTX) SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The NSTX Project will provide a national facility for the study of plasma confinement, heating, and current drive in a low aspect ratio, spherical torus (ST) configuration, The ST configuration is an alternate confinement concept which is characterized by high beta, high elongation, high bootstrap fraction, and low BT compared to conventional tokamaks, NSTX is the next step ST experiment following smaller experiments such as the PPPL CDX-U (Current Drive Experiment, Upgrade), the START (Small Tight Aspect Ratio Tokamak) at Culham, and the HIT (Helicity Injected Tokamak) at University of Washington, and is similar in scale to the MAST (Meg-Amp Spherical Tokamak) machine now under construction at Culham. This paper provides a description of mission and gives an overview of the main engineering features of the design of the machine and facility and discusses some of the key design solutions. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08540 USA. RP Neumeyer, C (reprint author), Princeton Univ, Plasma Phys Lab, Princeton, NJ 08540 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 221 EP 226 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300042 ER PT B AU Mueller, D Blanchard, W Doyle, BL Hosea, JC Nagy, A Pearson, G Skinner, CH Ulrickson, MA Wampler, WR Zweben, SJ AF Mueller, D Blanchard, W Doyle, BL Hosea, JC Nagy, A Pearson, G Skinner, CH Ulrickson, MA Wampler, WR Zweben, SJ GP IEEE IEEE IEEE TI Tritium retention and removal on TFTR SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Tritium retention and removal are critical issues for the success of ITER or any DT fusion reactor. The Tokamak Fusion Test Reactor, TFTR, is the first fusion facility to afford the opportunity to study the tritium retention and removal over an extended period. In TFTR, tritium accumulates on all surfaces with line of sight to the plasma by codeposition of tritium with carbon. Measurements of both deuterium and tritium retention fractions have yielded retention between 0.2 and 0.6 of the injected fuel in the torus. Tritium has been successfully removed from TFTR by glow discharge cleaning and by air purges. The in-vessel inventory was reduced by a factor of 2, facilitating machine maintenance. In TFTR, the amount of dust recovered from the TFTR vacuum vessel has varied from several grams to a few kilograms. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Mueller, D (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 2 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 279 EP 282 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300055 ER PT B AU Gentile, CA Kalish, M Amarescu, E Benson, J Blanchard, W Bunting, C Bush, S Camp, R Carpe, A Carnevale, RH Casey, M Ciebiera, L Connell, S Gibson, M Hawryluk, R Hatcher, R Hawes, R Homer, S Hosea, J Hyatt, D Kearns, E Kozub, T Langford, J Langish, S Marsala, R Montague, J Nagy, A Pearson, G Quigley, M Raftopoulos, S Raucci, R Reeves, D Rogers, E Schobert, J Shaltis, D Sichta, P Such, C Vinson, S Viola, M von Halle, A Walker, W Walters, T Williams, S Yager, R AF Gentile, CA Kalish, M Amarescu, E Benson, J Blanchard, W Bunting, C Bush, S Camp, R Carpe, A Carnevale, RH Casey, M Ciebiera, L Connell, S Gibson, M Hawryluk, R Hatcher, R Hawes, R Homer, S Hosea, J Hyatt, D Kearns, E Kozub, T Langford, J Langish, S Marsala, R Montague, J Nagy, A Pearson, G Quigley, M Raftopoulos, S Raucci, R Reeves, D Rogers, E Schobert, J Shaltis, D Sichta, P Such, C Vinson, S Viola, M von Halle, A Walker, W Walters, T Williams, S Yager, R GP IEEE IEEE IEEE TI The operation of the TFTR tritium system SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB In April of 1993 PPPL embarked upon the tritium operations phase of the TFTR project. Four years later, in the early morning of April 4, 1997, TFTR pulsed with tritium for the last time. In those four years, approximately 1 mega Curie of tritium was processed, and a Tritium purification System (TPS) was commissioned. During this period > 1,000 invasive (line break) operations were performed with < 425 CL of tritium released to the environment. The highly successful operation of the TFTR tritium systems was due to a corporate culture which stressed the importance of safe operations and the commitment by the TFTR staff to conduct nuclear operations in an efficient and safe fashion. The operation of TFTR as a nuclear facility employed 1,096 detailed operations procedures which were adhered to by all nuclear operations personnel and included a clear chain of command for nuclear operations. The successful start of TFTR D-T plasma operations on the evening of December 11, 1993, marked the first time that a D-T fueled plasma was produced in an American Fusion Reactor. This, coupled with the >1000 D-T plasmas over the next several years, was the result of detailed plans and analysis. The same level of detailed planning and attention to safe nuclear operations led to the successful commissioning and operation of the Tritium Purification System, which recycled similar to 8 grams of tritium prior to shutdown as the result of TFTR decommissioning, The real time tracking of tritium at the site was accomplished by a multi-compartment tritium accounting system which employed ion-chambers, mass spectrometers, beta scintillator, and calibrated volumes for PVT inventory determination. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Gentile, CA (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 283 EP 285 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300056 ER PT B AU Nobile, A Nasise, JE Schmierer, EN Walthers, CR Alexander, NB Besenbruch, GE Goodin, DT Harding, D Lund, L AF Nobile, A Nasise, JE Schmierer, EN Walthers, CR Alexander, NB Besenbruch, GE Goodin, DT Harding, D Lund, L GP IEEE IEEE IEEE TI Status of the design of the tritium handling systems for the OMEGA Cryogenic Target System SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The OMEGA Laser Facility at the University of Rochester Laboratory for Laser Energetics (UR/LLE) will begin laser illumination campaigns on cryogenic DT ICF targets in the year 2000. The OMEGA Cryogenic Target System (OCTS) will fill plastic ICF targets to high pressure, cool them to cryogenic temperature, layer and characterize targets, then transport them to the center of the OMEGA Target Chamber where they will be illuminated by a 30 kJ laser. The OCTS is being designed and constructed by General Atomics. Although the quantities of tritium being handled are relatively small (<1 g), the tritium handling systems to support the OCTS operation are significant. The high pressure system must compress DT at a very slow and uniform rate to pressures in excess of 1500 atm. This must be accomplished under the constraint of <1 g tritium inventory. The gloveboxes that provide secondary containment of the tritium handling equipment are relatively large, and one glovebox in particular must support a 1700 kg cryostat vessel, contain the vacuum and gas handling systems, and allow for access to the cryostat vessel for maintenance and repair when it becomes tritium contaminated. There are two major vacuum systems that support the OCTS operation. These were designed to be tritium compatible, relatively compact, easy to maintain, and yet provide high vacuum and roughing vacuum to a number of vessels having a wide range of tritium contamination levels. Finally, Tritium Removal Systems (TRSs) are being designed to provide cleanup of the glovebox atmosphere, vacuum system effluents, and equipment associated with the Target Chamber. The TRS must perform in a manner to support a yearly tritium release limit of 150 mCi of tritium, which is a significant challenge. This paper describes the current status as well as some of the challenges encountered in the design of the DT high pressure system, the gloveboxes, the vacuum system, and the TRSs. C1 Univ Calif Los Alamos Natl Lab, Tritium Sci & Engn Grp, Los Alamos, NM 87544 USA. RP Nobile, A (reprint author), Univ Calif Los Alamos Natl Lab, Tritium Sci & Engn Grp, POB 1663, Los Alamos, NM 87544 USA. RI Harding, David/F-5913-2012 NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 286 EP 291 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300057 ER PT B AU Blanchard, W Camp, R Carnevale, H Casey, M Collins, J Gentile, CA Gibson, M Hosea, JC Kalish, M Langford, J Langish, S Miller, D Nagy, A Pearson, GG Raucci, R Rule, K Winston, J AF Blanchard, W Camp, R Carnevale, H Casey, M Collins, J Gentile, CA Gibson, M Hosea, JC Kalish, M Langford, J Langish, S Miller, D Nagy, A Pearson, GG Raucci, R Rule, K Winston, J GP IEEE IEEE IEEE TI Tritium reduction and control in the vacuum vessel during TFTR outage and decommissioning SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB In the summer/fall of 1996 after nearly three years of D-T operations, TFTR underwent an extended outage during which large port covers were removed from the vacuum vessel in order to complete upgrades to the tokamak, Following the venting of the torus, a three tier system was developed for the outage in order to reduce and control the free tritium in the vacuum vessel so as to minimize the exposure to personnel during port cover removal and reinstallation, The first phase of the program to reduce the free tritium consisted of direct flowthrough of room air through the vacuum vessel to the molecular sieve beds using the Torus Cleanup System. Real time measurements of the effluent tritium concentration were used to derive the amount of tritium removed from the torus, Once the tree tritium in the vessel had been reduced to approximately 50 Ci, a second phase was initiated using a 55 Gallon Drum Bubbler System for the direct processing of the vacuum vessel to further lower the tritium level in the torus, Tritium oxide Is absorbed by the bubbler system with the exhaust vented to one of the tritium monitored HVAC ventilation stacks, To preclude the release of tritium to the Test Cell location of TFTR and to minimize the exposure of workers, a variable flow exhaust system was employed in order to maintain a negative pressure in the vacuum vessel between 0.05" and 1.5" w.c. during the removal of port covers ranging in size from approximately 5 to 1000 in(2), These systems were completely successful in reducing and controlling the free tritium in TFTR and were Instrumental In maintaining ALARA (As Low As Reasonably Achievable) exposures to tritium during the 1996 outage. These systems are again being utilized during the safe shutdown and decommissioning of TFTR which commenced in April of 1997, This paper describes In detail the configuration of these systems and the data obtained during the outage and sate shutdown of TFTR. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Blanchard, W (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 297 EP 300 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300059 ER PT B AU Birdsell, SA Willms, RS Arzu, P Costello, A AF Birdsell, SA Willms, RS Arzu, P Costello, A GP IEEE IEEE IEEE TI Effect of inlet conditions on the performance of a palladium membrane reactor SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Palladium membrane reactors (PMR) are used to remove tritium and other hydrogen isotopes from impurities such as tritiated methane and tritiated water. This paper investigates the effect of inlet conditions on the performance of a PMR. ii set of experiments were run to determine, independently, the effect of inlet compositions and residence time on performance. Also, the experiments were designed to determine if the injected form of hydrogen (CH4 or H2O) effects performance. Results show that the PMR operates at optimal hydrogen recovery with a broad range of inlet compositions and performance is shown to increase with increased residence time. PMR performance is shown to be independent of whether hydrogen is injected in the form of CH4 or H2O. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Birdsell, SA (reprint author), Univ Calif Los Alamos Natl Lab, MS C348, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 301 EP 303 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300060 ER PT B AU Willms, RS Tuggle, D Birdsell, S Parkinson, J Price, B Lohmeir, D AF Willms, RS Tuggle, D Birdsell, S Parkinson, J Price, B Lohmeir, D GP IEEE IEEE IEEE TI Comparison of methods for separating small quantities of hydrogen isotopes from an inert gas SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB It is frequent within tritium processing systems that a small amount of hydrogen isotopes (Q(2)) must be separated from an inert gas such as He, Ar and N-2. Thus, a study of presently available technologies for effecting such a separation was performed. A "base case" and seven technology alternatives were identified and a simple design of each was prepared. These technologies included oxidation-adsorption-metal bed reduction, oxidation-adsorption-palladium membrane reactor, cryogenic adsorption, cryogenic trapping, cryogenic distillation, hollow fiber membranes, gettering and permeators. It was found that all but the last two methods were unattractive for recovering Q(2) from N2- Reasons for technology rejection included 1) the method unnecessarily turns the hydrogen isotopes into water, resulting in a cumbersome and more hazardous operation, 2) the method would not work without further processing, and 3) while the method would work, it would only do so in an impractical way. On the other hand, getters and permeators were found to be attractive methods for this application. Both of these methods would perform the separation in a straightforward, essentially zero-waste, single step operation. The only drawback for permeators was that limited low-partial Q(2) pressure data is available. The drawbacks for getters are their susceptibility to irreversible and exothermic reaction with common species such as oxygen and water, and the lack of long-term operation of such beds. More research is envisioned for both of these methods to mature these attractive technologies. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Willms, RS (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 304 EP 308 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300061 ER PT B AU Sherman, RH Taylor, DJ Honnell, KG O'hira, S Kawamura, Y Nishi, M Okuno, K AF Sherman, RH Taylor, DJ Honnell, KG O'hira, S Kawamura, Y Nishi, M Okuno, K GP IEEE IEEE IEEE TI Radiochemical reactions between tritium and humid air SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Radiochemical reactions between pure tritium (T-2) and moist air have been examined using real-time Raman spectroscopy. The reacting constituents were contained in a 1 cm(3) quartz cell sealed by a quartz-to-metal seal leading to a valve. A near-stoichiometric mixture of T-2 and O-2 was introduced into the cell, and the time evolution of the composition was monitored at 297 K for twenty-nine days. The production of T2O was observed in these experiments, for the first time unambiguously detected in Raman spectroscopy. T2O exhibits a relatively weak vibrational band at similar to 2241 cm(-1). The radiochemical production of tritiated water did not occur in the expected 2:1 ratio, but rather with the O-2 disappearing totally when the T-2 was only slightly over halfway depleted. After the disappearance of O-2, the T-2 partial pressure continued to decrease, but at a slower rate. The initial water in the moist-air mixture disappeared totally after about 15 hours, with no concomitant production of HT. A small quantity of CO2 was also detected, presumably produced by radiochemically driven reactions with stainless steel components. C1 Univ Calif Los Alamos Natl Lab, Tritum Syst Test Assembly, Los Alamos, NM 87545 USA. RP Sherman, RH (reprint author), Univ Calif Los Alamos Natl Lab, Tritum Syst Test Assembly, MS C332, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 313 EP 316 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300063 ER PT B AU Nagy, A Amerescu, E Blanchard, W Camp, R Casey, M Chase, K Cropper, M Czeizinger, T DiMattia, M Gentile, C Gething, J Gibson, M Langford, J Hosea, J Hyatt, D Kalish, M Kamperschroer, J Langish, S Miller, D Mueller, D Pearson, G Raftopoulos, S Raucci, R Stevenson, T VonHalle, A Winston, J AF Nagy, A Amerescu, E Blanchard, W Camp, R Casey, M Chase, K Cropper, M Czeizinger, T DiMattia, M Gentile, C Gething, J Gibson, M Langford, J Hosea, J Hyatt, D Kalish, M Kamperschroer, J Langish, S Miller, D Mueller, D Pearson, G Raftopoulos, S Raucci, R Stevenson, T VonHalle, A Winston, J GP IEEE IEEE IEEE TI Tritium recovery from the TFTR vessel SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The Tokamak Fusion Test Reactor (TFTR) was supplied over 7.5x10(5) Curies combined through the vacuum vessel and Neutral Beam (NB) tritium gas injectors. Out of this quantity approximately 29,530 Curies (Ci) has entered the vacuum vessel as neutral atoms, including cold streaming gas and 20,270 Ci as direct vessel injection. TFTR has had two short term outages during DT operations (Outage 1('95) & 2('96), plus the final shutdown, Outage 3 ('97), after DT operations in which tritium held up in the vessel and NB's has been actively recovered. The respective recovery values are: Outage (No.1) 8,257 Ci, (No. 2) 4,668 Ci and No. 3 final shutdown) 3965 Ci. The methods for recovering this included: 1.) Vessel baking to 150 degrees C during Deuterium Glow Discharge Cleaning (DGDC), 2.) Helium/Oxygen GDC (HeOGDC), 3.) Pulse Discharge Cleaning (PDC), 4.) Continuous moist air purges and 5.) Dry air, moist air (40% RH), and deuterium vent/soak/pump. The processes showing equivalent efficiency are the GDC, HeOGDC, and moist air purges at elevated temperatures. A small amount of tritium is introduced in the vessel at high energy through the NE similar to 3% relative to that supplied to the beam lines and similar to 1/2 of this is essentially buried in the carbon composite tiles and has a longer time constant for removal than the direct vessel injected tritium. Data shows that the bulk of surface tritium is removed by active cleaning methods and in the presence of moist air purges (room air at similar to 40% relative humidity) combined with elevated temperatures which accelerates its removal. Continuous outgassing at low levels in the presence of moist air (750 Torr) follows the active tritium removal processes and moist air purges. The TFTR tritium removal processes and their corresponding removal rates and quantities are reported. An ion chamber is used to measure the tritium accumulated in the Gas Holding Tanks (GHT) from the vessel throughout all the active and passive processes. The ion chamber compensation for varying gas mixtures was found to be critical in accurate measurement of this recovery and is discussed. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Nagy, A (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 317 EP 320 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300064 ER PT B AU Skinner, CH Kugel, H Mueller, D Doyle, BL Wampler, WR AF Skinner, CH Kugel, H Mueller, D Doyle, BL Wampler, WR GP IEEE IEEE IEEE TI Tritium removal by CO2 laser heating. SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Efficient techniques for rapid tritium removal will be necessary for ITER to meet its physics and engineering goals. One potential technique is transient surface heating by a scanning CO2 or Nd:Yag laser that would release tritium without the severe engineering difficulties of bulk heating of the vessel We have modeled the heat propagation into a surface layer and find that a multi-kW/cm(2) flux with a exposure time of order 10 ms is suitable to heat a 50 micron co-deposited layer to 1,000-2,000 degrees. Improved wall conditioning may be a significant side benefit. We identify remaining issues that need to be addressed experimentally. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Skinner, CH (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 321 EP 324 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300065 ER PT B AU Odegard, BC Cadden, CH Watson, RD Nygren, R Slattery, KT AF Odegard, BC Cadden, CH Watson, RD Nygren, R Slattery, KT GP IEEE IEEE IEEE TI A review of the US joining technologies for plasma facing components in the ITER fusion reactor SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB This paper is an overview of joining technologies developed for the fabrication of duplex armor/heat sink structures for use as actively cooled plasma facing components (PFC's). Tore Supra has been facing the challenge of implementing such technology with carbon armor brazed to copper alloy heat sinks for several years. Also, extensive preparations were made for the deployment of actively cooled limiters with beryllium armor joined to copper alloy heat sinks in the Joint Eurpean Torus (JET). With the development of plasma facing components for the International Thermonuclear Experimental Reactor (ITER), there has been a trend toward fabrication of more sophisticated structures to deal with the challenges of relatively long component lifetimes under high thermal loads. This paper summarizes earlier work on Tore Supra and JET as well as current efforts in the US in developing adequate joining technologies for ITER plasma facing components. For ITER, many unique and innovative joining techniques are being considered in the quest to join two candidate armor materials (beryllium and tungsten) to a copper base alloy heat sink (CuNiBe, DS copper, or CuCrZr). These techniques include brazing and diffusion bonding, incorporating compliant layers, diffusion barrier coatings and diffusion enhancing coatings at the bond interfaces. At this writing, two beryllium-copper divertor mock-ups have survived 1000 thermal cycles at IO MW/m(2) without damage during testing at the electron beam test system (EBTS) facility at Sandia National Laboratories in New Mexico. A plasma-sprayed (Be on Cu) ITER first wall mock-up has survived 3000 cycles at 1 MW/m(2) without damage. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Odegard, BC (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 1 U2 5 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 337 EP 343 PG 7 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300068 ER PT B AU Brunkhorst, C AF Brunkhorst, C GP IEEE IEEE IEEE TI RF cavity analysis with spreadsheet software SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB High power RP systems are commonly used in fusion research. At Princeton, they are required to deliver power in the megawatt range at frequencies of 30 to 80 Mhz. As both frequency and power output are increased, circuits composed of conventional inductors and capacitors become difficult to realize. Under these conditions, cavities composed of sections of transmission line are employed as tuned circuits. A simple method Is presented, whereby transmission line impedance transformations are calculated utilizing spreadsheet software such as Microsoft(R) Excel. From these calculations, RF cavity models may be constructed, yielding information such as plate impedance, currents and voltages at various points In the cavity, and bandwidth. This method was used In the design to convert both 80, and 40 - 80 Mhz FMIT sources to 30 MHz, for use on TFTR. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Brunkhorst, C (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 449 EP 451 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300094 ER PT B AU Greenough, N Brunkhorst, C Clark, R Fredd, E Martin, A AF Greenough, N Brunkhorst, C Clark, R Fredd, E Martin, A GP IEEE IEEE IEEE TI Design of the final power amplifier stage for the 30 MHz TFTR FMIT RF sources SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Two of the 80 MHz transmitters originally built for the Fusion Materials Irradiation Test facility (FMIT) by Continental Electronics Manufacturing Company were converted by PPPL RF Engineering to operate at 30 MHz in the TFFR ICRF System. This system consists of sir multimegawatt RF sources providing radio frequency power to antennas located Pt four bays on TFTR Power levels of more than two megawatts have been supplied by each of these sources at pulse widths of three seconds. This paper presents the detailed design and analyses of the Final Power Amplifier (FPA) stage of these new sources and its subsequent fabrication and commissioning The FPA utilizer re-entrant cavities similar in design to those used in the Intermediate Power Amplifier and Driver stages. A brief description of the sources' setup to accommodate impedance variations of plasma-loaded antennas is also included. Finally, an overview of the ICRF tube protection system ir discussed. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Greenough, N (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 452 EP 455 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300095 ER PT B AU Martin, A Brunkhorst, C Clark, R Fredd, E Greenough, N AF Martin, A Brunkhorst, C Clark, R Fredd, E Greenough, N GP IEEE IEEE IEEE TI New 30 MHz TFTR high power ICRF sources SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The TFTR ICRF system consists of sir multimegawatt RF sources providing radio frequency power to antennas located at four bays on TFTR Power levels of more than two megawatts have been supplied by each of these sources at pulse widths of three seconds. Two of the sources were designed and built by the Princeton Plasma Physics Laboratory's (PPPL) RF Engineering group and currently operate at 30 MHz. The other four sources are modified versions of the 80 MHz transmitters originally built for the Fusion Materials Irradiation Test facility by continental Electronics Manufacturing company. Prior to fiscal year 1997 (FY97), the modified FMIT sources operated over the 40-to-80 MHz frequency range. At the end of FY96, two of PPPL's 40-80 MHz FMIT sources were loaned to Massachusetts Institute of Technology (MIT) to support the C-MOD experimental program PPPL replaced these sources with two new 30 MHz sources. These units were assembled both from new cavity components designed by PPPL and from components of some of the original 80 MHz FMITs stored at Princeton. The new 30 MHz EMIT sources were commissioned and operational on TFTR in February 1997. This paper describes the detailed design and analysis of the Intermediate Power Amplifier and Driver stages of these new sources and their subsequent fabrication and commissioning. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Martin, A (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 456 EP 458 PG 3 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300096 ER PT B AU Reass, WA Miera, DA Wurden, GA AF Reass, WA Miera, DA Wurden, GA GP IEEE IEEE IEEE TI Initial design of the 60 Megawatt rotating magnetic field (RMF) oscillator system for the University of Washington "TCS" field reversed configuration experiment SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB This paper presents the initial electrical and mechanical design of two phase-locked 30 Megawatt RMS, 150 kHz oscillator systems used for current drive and plasma sustainment of the "Translation, Confinement, and Sustainment" (TCS) field reversed configuration (FRC) plasma. By the application of orthogonally-placed saddle coils on the surface of the glass vacuum vessel, the phase-controlled rotating magnetic field perturbation will induce an electric field in the plasma which should counter the intrinsic ohmic decay of the plasma and maintain the FRC. Each system utilizes a bank of 6 parallel magnetically beamed ML8618 triodes. These devices are rated at 250 Amperes cathode current and a 45 kV plate voltage. An advantage of the magnetically beamed triode is their extreme efficiency, requiring only 2.5 kW of filament and a few amps and a few kV of grid drive. Each 3.5 uH saddle coil is configured with an adjustable tank circuit (for tuning). Assuming no losses and a nominal 18 kV plate voltage, the tubes can circulate about 30 kV and 9 kA (pk to pk) in the saddle coil antenna, a circulating power of over 33 megawatts RMS. On each cycle the tubes can kick in up to 1500 Amperes, providing a robust phase control. DC high-voltage from the tubes is isolated from the saddle coil antennas and tank circuits by a 1:1 coaxial air-core balun transformer. To control the ML8618's phase and amplitude, fast 150 Ampere "totem-pole" grid drivers, an "on" hot-deck and an "off" hot-deck are utilized. The hot-decks use up to 6 each 3CPX1500A7 slotted radial beam triodes. By adjusting the conduction angle, amplitude may be regulated, with inter-pulse timing, phase angle can be controlled. A central feedback timing chassis monitors each systems' saddle coil antenna and appropriately derives each systems timing signals. Fiber-optic cables are used to isolate between the control room timing chassis and the remote power oscillator system. Complete system design detail will be presented in addition to anticipated (computer generated) performance characteristics. Initial design and construction began in FY97, and will continue through FY98, with delivery to the experiment in FY99, for commencement of physics experiments on sustaining the FRC. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Reass, WA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Wurden, Glen/A-1921-2017 OI Wurden, Glen/0000-0003-2991-1484 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 473 EP 476 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300101 ER PT B AU Reass, WA Wurden, GA Nadle, DL Mauel, ME Navratil, GA AF Reass, WA Wurden, GA Nadle, DL Mauel, ME Navratil, GA GP IEEE IEEE IEEE TI Operational performance of the two channel 10 megawatt feedback amplifier system for MHD control on the Columbia University HBT-EP tokamak SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The operational characteristics and performance of the two channel 10 Megawatt MHD feedback control system as installed by Los Alamos National Laboratory on the Columbia University HBT-EP tokamak are described. In the present configuration, driving independent 300 uH saddle coil sets, each channel can deliver 1100 Amperes and 16 kV peak to peak. Full power bandwidth is about 12 kilt, with capabilities at reduced power to 30 kHz. The present system topology is designed to suppress magnetohydrodynamic activity with m=2 n=1 symmetry. Application of either static (single phase) or rotating (twin phased) magnetic perturbations shows the ability to spin up or slow down the plasma, and also prevent (or cause) so-called "mode-locking". Open loop and active feedback experiments using a digital signal processor (DSP) have been performed on the HBT-EP tokamak and initial results show the ability to manipulate the plasma MHD mode frequency. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Reass, WA (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. RI Wurden, Glen/A-1921-2017; OI Wurden, Glen/0000-0003-2991-1484; Mauel, Michael/0000-0003-2490-7478 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 497 EP 500 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300105 ER PT B AU Sichta, P Chu, J Mueller, D AF Sichta, P Chu, J Mueller, D GP IEEE IEEE IEEE TI TFTR realtime control applications using the Digital Plasma Control System SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB This paper describes the design, development, and operating experiences using the Digital plasma Control System on the Tokamak Fusion Test Reactor(TFTR). This VME-based system has been used for three real-time control applications on TFTR, plasma position and current control, piezoelectric valve control using pulse width modulation, and impurity gas injection feedback control. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Sichta, P (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 501 EP 504 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300106 ER PT B AU Hatcher, RE Okabayashi, M Pomphrey, N Sichta, P Woolley, R AF Hatcher, RE Okabayashi, M Pomphrey, N Sichta, P Woolley, R GP IEEE IEEE IEEE TI Resistive wall mode feedback stabilization studies using a lumped-parameter circuit equation formulation SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The role of the resistive wall mode in limiting tokamak plasma performance is well chronicled and is a central topic of the Feedback Stabilization Initiative (FSI). It is believed that stabilization of this mode, which is a converted branch of the ideal-MHD external kink mode, may lead to the design of devices capable of accessing higher performance advanced operating regimes. We have developed a formulation of the resistive wail mode, for the limiting case of infinite aspect ratio, using the elementary physical concepts of self and mutual inductance. This results in a set of coupled lumped-parameter circuit equations with the variables being the perturbed plasma current, the helical component of induced current in the resistive shell, and (with feedback) the current in the active coil. These equations, which describe plasma perturbations of n greater than or equal to 1, have a one to one correspondence with plasma vertical positional n = 0 control. Comparisons between the dispersion relations for the two cases show that the quantity that carries the strength of the instability for the resistive wall mode, equivalent to the negative decay index in vertical position control, is L-pl(1 - f) where L-pl is the helical inductance of the perturbed plasma current and (1 - f) is related to the helicity of the ideal-MHD kink mode. This method has been applied successfully to describe the resistive wall mode in general terms and to describe analytically resistive wall mode feedback stabilization schemes. Formulation in this manner should facilitate numerical simulation of resistive wall mode feedback schemes. In this paper, we will describe the formulation in detail, show how the resulting circuit equations compare to the equations arrived at using traditional MHD analysis methods (particularly with the inclusion of feedback), and compare the resistive wall mode equations to those that describe the (n = 0) vertical instability. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Hatcher, RE (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 513 EP 516 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300109 ER PT B AU Kugel, HW Boedo, J Chance, M Goldston, R Jardin, S Kesner, J Luckhardt, S Manickam, J McGuire, K Okabayashi, M Schmidt, J Schmitz, L Zakharov, L AF Kugel, HW Boedo, J Chance, M Goldston, R Jardin, S Kesner, J Luckhardt, S Manickam, J McGuire, K Okabayashi, M Schmidt, J Schmitz, L Zakharov, L GP IEEE IEEE IEEE TI Feedback stabilization experiment for MHD control with edge current SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Two conceptual designs were investigated for an experimental facility with sufficient versatility to evaluate active mode stabilization of high power tokamak edge plasmas. This paper discusses the experimental facilities required to evaluate five innovative methods for edge control and feedback stabilization. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kugel, HW (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 517 EP 522 PG 6 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300110 ER PT B AU Woolley, RD AF Woolley, RD GP IEEE IEEE IEEE TI Magnetic plasma feedback stabilization design SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Engineering Issues relevant to the design of magnetic based systems for plasma feedback stabilization of internal tearing modes and resistive wall modes are discussed herein. Proposed design optimization methods are delineated, and are then illustrated In practice by applying them to the example design of a hypothetical experimental plasma feedback stabilization demonstration facility. In addition to the physical dynamics of the plasma itself and of the eddy current behavior of metallic structures close to the plasma, the plasma feedback system includes magnetic field sensors distributed spatially near the plasma, digital signal processing electronics to implement an optimal state-estimating "observer" and an optimal controller, and also electromagnets and their associated power circuitry. The magnetic field sensors must be sufficiently numerous and spatially well distributed so that each unstable plasma eigenmode can be resolved without spatial aliasing. Digital signal processing algorithms must be sufficiently fast to continually estimate the amplitude,phase, and rotation rate of each unstable eigenmode based on the magnetic field sensors' signal histories. They must be sufficiently sophisticated to discriminate between field amplitude components produced directly by the plasma perturbations and the components produced In response to optimal controller commands, and they should be sufficiently robust for a range of plasma parameters. The electromagnets must be located close enough to the plasma to drive a controlled opposing field with the proper resolution of helical shapes, and their power circuitry must be capable of producing the commanded amplitude, phase, and rotation rates for the driven field. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Woolley, RD (reprint author), Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 523 EP 526 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300111 ER PT B AU Bashore, D Oliaro, G Roney, P Sichta, P Tindall, K AF Bashore, D Oliaro, G Roney, P Sichta, P Tindall, K GP IEEE IEEE IEEE TI Conceptual design for the NSTX central instrumentation and control system SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The design and construction phase for the National Spherical Torus Experiment (NSTX) is under way at the Princeton Plasma Physics Laboratory (PPPL). Operation is scheduled to begin on April 30, 1999. This paper describes the conceptual design for the NSTX Central Instrumentation and Control (I&C) System. Major elements of the Central I&C System include the Process Control System, Plasma Control System, Network System, Data Acquisition System, and Synchronization System to support the NSTX experimental device. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Bashore, D (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 535 EP 538 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300114 ER PT B AU Payne, SA Beach, RJ Bibeau, C Ebbers, CA Emanuel, MA Honea, EC Krupke, WF Marshall, CD Orth, CD Powell, HT Schaffers, KI Skidmore, JA Sutton, SB AF Payne, SA Beach, RJ Bibeau, C Ebbers, CA Emanuel, MA Honea, EC Krupke, WF Marshall, CD Orth, CD Powell, HT Schaffers, KI Skidmore, JA Sutton, SB GP IEEE IEEE IEEE TI Recent advances and challenges for diode-pumped solid-state lasers as an inertial fusion energy driver candidate SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB We discuss how solid-state laser technology can serve in the interests of fusion energy beyond the goals of the National Ignition Facility (NIF), which is now being constructed to ignite a deuterium-tritium target to fusion conditions in the laboratory for the first time. We think that advanced solid-state laser technology can offer the repetition-rate and efficiency needed to drive a fusion power plant, in contrast to the single-shot character of NIF, As discussed below, we propose that a gas-cooled, diode-pumped Yb:S-FAP laser can provide a new paradigm for fusion laser technology leading into the next century. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Payne, SA (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-441, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 583 EP 587 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300125 ER PT B AU Meier, WR Bangerter, RO Faltens, A AF Meier, WR Bangerter, RO Faltens, A GP IEEE IEEE IEEE TI Systems modeling for heavy ion drivers - An induction linac example SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB A source-to-target model for an induction linac driver for heavy ion fusion has been developed and is described here. Design features for a reference case driver that meets the requirements of one current target design are given, and the systems analyses supporting the point design are discussed. Directions for future work are noted. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Meier, WR (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 598 EP 602 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300128 ER PT B AU Chrzanowski, J Spitzer, J Citrolo, J Brooks, A Fan, HM Neumeyer, C Heitzenroeder, P AF Chrzanowski, J Spitzer, J Citrolo, J Brooks, A Fan, HM Neumeyer, C Heitzenroeder, P CA NSTX Team GP IEEE IEEE IEEE TI National Spherical Torus Experiment (NSTX) - Center Stack design and assembly SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The National Spherical Torus Experiment (NSTX) is a low aspect ratio, spherical torus (ST) configuration device under construction at PPPL. One of the most complex components of this device Is the Center Stack Assembly (CSA). The CSA measures 5.7 meters (18.6 feet) in length and 34.2 cm. (13.476 in.) in diameter. It consists of the inner legs of the Toroidal Field (TF) winding, the Ohmic Heating (OH) solenoid and Its associated tension cylinder, three inner Poloidal Field (PF) coils, thermal insulation, diagnostics and an Inconel casing which forms the inner wail of the vacuum vessel boundary. Some of the engineering issues associated with the CSA design and which are Included in this paper are loads, load paths and stresses on the CSA, material selection including conductor, insulation, and manufacturing/ assembly issues. An elaborate support structure Is required for reacting loads in the CSA. This structure includes a tension tube for supporting the OH coil and reacting the axial loads and hub assemblies at each end of the CSA to react electromagnetic loads on the bolted TF flags to act together as a monolithic structure. High insulation shear stresses of 16.6 MPa (2.4 ksi) were anticipated in the inner TF coil legs. It was necessary to establish a R&D program to determine the maximum shear strengths and fatigue life of the selected insulation. These R&D test results are included in the paper. The CSA is designed to be disassembled from the vacuum vessel in the event that future repairs or upgrades are required. The dimensional restraints on the outside diameter of the CSA has resulted in reduced clearances between components. This along with the excessive lengths combine to make the assembly of the CSA components a critical phase of the program. This paper provides a description of the NSTX CSA and reviews those engineering issues associated with the design. An overview of the NSTX is described in more detail in a companion paper (1). C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Chrzanowski, J (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 637 EP 640 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300136 ER PT B AU Bulmer, RH Neilson, GH AF Bulmer, RH Neilson, GH GP IEEE IEEE IEEE TI Alternative poloidal field configurations for ITER SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The US Home Team has investigated the physics and engineering issues for two alternate poloidal field coil configurations for ITER. The first is called the Segmented CS configuration, where all of the solenoid modules are pancake-wound. The second option, termed the Hybrid CS configuration, utilizes a layer-wound central module and pancake-wound end modules. Performance comparisons are presented for the baseline design and the two alternate PF configurations, characterizing the 21 MA reference scenario. Alternate operating modes such as reverse-shear operation and a 17 MA driven mode were evaluated, but are not reported here. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Bulmer, RH (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 685 EP 688 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300148 ER PT B AU Heitzenroeder, P Brooks, A Citrolo, J Dahlgren, F Neilson, H Montgomery, DB Sborchia, C AF Heitzenroeder, P Brooks, A Citrolo, J Dahlgren, F Neilson, H Montgomery, DB Sborchia, C GP IEEE IEEE IEEE TI Engineering overview of the ITER hybrid central solenoid SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The hybrid central solenoid was proposed as a possible alternative to the segmented central solenoid since it avoids the most serious issue of the segmented solenoid design: the placement of superconducting joints in a 13 T field. The hybrid is so named because it adopts features from both the reference and segmented designs in a configuration which results in the fields at the superconducting joints being similar to those in the reference design. This paper overviews the engineering details of the reference, segmented, and hybrid designs and discusses the tradeoffs involved in the various designs. Although the hybrid was not adopted for the EDA design due to unresolved issues, it evolved into the present reference design which includes some of the design details of the hybrid. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Heitzenroeder, P (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 693 EP 696 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300150 ER PT B AU Reiersen, WT Neilson, GH Jardin, SC Hill, DN Park, HK Young, KM Chang, CS Nevins, W Brown, T Schultz, J Sevier, L Cho, S Kim, J Lee, GS AF Reiersen, WT Neilson, GH Jardin, SC Hill, DN Park, HK Young, KM Chang, CS Nevins, W Brown, T Schultz, J Sevier, L Cho, S Kim, J Lee, GS GP IEEE IEEE IEEE TI The design of the Korea superconducting tokamak advanced research (KSTAR) SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The KSTAR team is carrying out the design and research and development for a steady-state-capable advanced superconducting tokamak to establish the basis for an attractive fusion reactor as a future energy source, The physics requirements are driven by the plasma control and exhaust capabilities needed to extend the performance and pulse length of tokamak plasmas. The tokamak has major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 T and plasma current 2MA, a strongly shaped plasma cross-section shaping (elongation 2.0 and triangularity 0.8), and a double-null poloidal divertor. The initial pulse length is 20 s, long enough to study physics on confinement timescales, but short enough to permit economical plasma-facing component technology. The pulse length can be increased to 300 s through upgrades. The machine will be operable in either hydrogen or deuterium, but neutron yields will be constrained to avoid the cost and inconvenience of remote maintenance and low-activation materials. The magnet system provides an inductively driven 20 s pulse with full current, beta, and shaping. With non-inductive current drive, steady-state plasmas can be sustained over a wide range of profile shapes and plasma pressures. Passive structures are provided to stabilize the vertical instability and high-beta modes and internal coils are provided for fast position control. The divertor structures are designed for particle removal, recycling control, impurity control, and flexibility for advanced divertor operation. The plasma heating system is designed for heating, current-drive, profile control, and flexibility. It will deliver power via neutral beams (8 MW), ion-cyclotron waves (6 MW), and lower-hybrid waves (1.5 MW), each of which can be expanded through upgrades. A comprehensive set of diagnostics is planned for plasma control, performance evaluation, and physics understanding. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Reiersen, WT (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 725 EP 728 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300157 ER PT B AU Peng, YKM Cheng, ET Galambos, JD Strickler, DJ Berk, SE AF Peng, YKM Cheng, ET Galambos, JD Strickler, DJ Berk, SE GP IEEE IEEE IEEE TI Physics and systems design analyses for spherical torus (ST) based VNS SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Physics and systems design analyses are carried out to estimate the desired fusion core parameters for an ST based Volume Neutron Source (ST-VNS) that utilizes a single-turn toroidal field coil (TFC). A design with a major radius R-o= 1.07 m is estimated to have large margins in physics, technology, and engineering for the initial operation at moderate performance (neutron wall load,W-L= 0.5-2.0 MW/m(2)). The VNS therefore begins with technologies already assumed in the ITER EDA, and the relatively conservative physics to be tested initially by the ST proof-of-principle experiments presently being built. Given continued advances in technology via the VNS and in physics via the ST experiments, the design should permit upgrades to test components and operation at the level of future Pilot Plant and Power Plants (W-L = 5 MW/m(2)). This approach to VNS places premium on modular components and remote maintenance, encourages continued innovation and optimization in ST fusion and plasma science, and enhances the practicality of the ST pathway to fusion power. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Peng, YKM (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 733 EP 736 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300159 ER PT B AU Post-Zwicker, AP Barnes, D Carroll, D Davis, W Pfaff, R Stotler, DP Williams, M Baron, J McKay, M Friedman, EA AF Post-Zwicker, AP Barnes, D Carroll, D Davis, W Pfaff, R Stotler, DP Williams, M Baron, J McKay, M Friedman, EA GP IEEE IEEE IEEE TI Using the Internet for Plasma Physics Education SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The current reform in K-12 science education emphasizes the creation of curricula that are student-led, hands-on, and open-ended. trend is based on current research examining the best practice in science learning and teaching. Computers are an important part of this change and the Internet adds a unique dimension to the possible ways that computers can be used as a learning tool. The Internet Plasma Physics Educational Experience (IPPEX) was created and modeled upon these principles to teach middle and high school students about plasma physics and fusion energy. Sections include a virtual tokamak, analysis of data from the TFTR experiment, and "ask a scientist". C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Post-Zwicker, AP (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. RI Stotler, Daren/J-9494-2015; OI Stotler, Daren/0000-0001-5521-8718; Davis, William/0000-0003-0666-7247 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 760 EP 763 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300166 ER PT B AU Nilson, DG Carlstrom, TN Hsieh, CL Stallard, BW Stockdale, RE AF Nilson, DG Carlstrom, TN Hsieh, CL Stallard, BW Stockdale, RE GP IEEE IEEE IEEE TI Central Thomson scattering upgrade on DIII-D SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The existing 36 channel Thomson scattering system on the DIII-D tokamak measures the plasma temperature and density in the core region. However, with the recent interest in core peaked density profiles, coverage needs to be extended into the magnetic axis. This paper addresses the technical issues involved with extending the viewing region from a major radius of 194 cm to 165 cm, At least one of the existing seven core laser beams will be rerouted to probe the plasma horizontally instead of vertically. To do this, a rigid extension of the existing laser/collection optics tower will be built to route the laser to a nearby tangential port. ii fiber bundle array from one of the two existing core plasma collection optics sets will be rotated to allow up to 10 of the 36 core channels to view along this new beam path, A new in-vessel absorbing glass laser dump must be developed since there are no appropriate laser beam exit ports. The close proximity of this laser dump to the viewing region presents stray light issues that must be resolved to allow for an accurate density calibration using Rayliegh scattering in argon gas. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Nilson, DG (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 791 EP 794 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300173 ER PT B AU Dudek, LE Bell, RE Palladino, R Parsells, RF AF Dudek, LE Bell, RE Palladino, R Parsells, RF GP IEEE IEEE IEEE TI Mechanical design of the TFTR poloidal rotation diagnostic SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB In the spring of 1997, a poloidal rotation diagnostic was installed on TFTR for the final DT experiments. This spectroscopic diagnostic was designed to measure the poloidal velocity to determine the radial electric field in the plasma. The collecting optics consist of a quartz window vacuum interface, two vertically opposed fan-shaped arrays of 1 mm quartz fibers and lens system. The design requirements, as well as short design to implementation schedule, led to some unique design features. To minimize errors introduced by the toroidal velocity component of the measurement, tight position requirements were placed on the alignment of the fiber optic assemblies relative to the tokamak and to each other. Activation and contamination of the TFTR vacuum vessel presented unique design issues for installation and precise alignment of the optics to 1 part in 1000 from outside the vacuum vessel. The design progressed from concept to implementation in less than six months requiring a relatively simple design. C1 Princeton Univ, Plasma Phys Lab, Princeton, NJ 08543 USA. RP Dudek, LE (reprint author), Princeton Univ, Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 795 EP 798 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300174 ER PT B AU Kugel, HW Gorman, J Johnson, D Labik, G Lemunyan, G Mansfield, D Timberlake, J Vocaturo, M AF Kugel, HW Gorman, J Johnson, D Labik, G Lemunyan, G Mansfield, D Timberlake, J Vocaturo, M GP IEEE IEEE IEEE TI Development of lithium deposition techniques for TFTR SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The ability to increase the quantity of lithium deposition into TFTR beyond that of the Pellet Injector while minimizing perturbations to the plasma provides interesting experimental and operational options. Two additional lithium deposition tools were developed for possible application during the 1996 Experimental Schedule: a solid lithium target probe for real-time deposition, and a lithium effusion oven for deposition between discharges. The lithium effusion oven was operated in TFTR to deposit lithium on the Inner Limiter in the absence of plasma. This resulted in the third highest power TFTR discharge. C1 Princeton Univ, Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kugel, HW (reprint author), Princeton Univ, Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 869 EP 872 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300191 ER PT B AU Labik, G Bartolick, J Gorman, J Johnson, D LeMunyan, G Long, D Mansfield, D Vocaturo, M AF Labik, G Bartolick, J Gorman, J Johnson, D LeMunyan, G Long, D Mansfield, D Vocaturo, M GP IEEE IEEE IEEE TI DOLLOP (Deposition of lithium by laser outside of plasma) - An overview SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB This paper describes the spallation of lithium into TFTR by laser and operated during the last run period. Liquid droplets of lithium were delivered into the edge of TFTR plasmas at Low velocities in order to coat the interior of the TFTR vacuum vessel, and study the effects on machine performance. A 1.6 Joule 1064 nm, 30 Hz pulsed YAG laser was used to form droplets from a heated cauldron containing liquid lithium. The cauldron was resistance heated and part of a new probe head attached to the existing Bay D Long Probe. The cauldron was moved into the bottom of the vacuum vessel and positioned in the shadow of a poloidal limiter. The laser, associated equipment, and beam expanding optics were located in a walled enclosure approximately 46m from the cauldron. Three fixed mirrors directed the beam through the test cell wall and into a box containing the focusing optics, steering mirror and a remote viewing CID video camera system. The focused beam was aimed vertically downward through a vacuum window and into the lithium cauldron. The system was controlled using LabView(TM) software. Safety issues were resolved with engineered hardware design, interlocked circuits and administrative control. Lithium was successfully introduced into TFTR. Some interesting physics results were obtained. There was insufficient time to optimize the operation and design but initial results point to interesting possibilities for future experiments. Laboratory tests indicated that the cauldron could feasibly be positioned horizontally or vertically. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Labik, G (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 873 EP 876 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300192 ER PT B AU Odegard, BC Cadden, CH AF Odegard, BC Cadden, CH GP IEEE IEEE IEEE TI Beryllium-copper diffusion bonding for an ITER first wall application SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Several different joint assemblies were evaluated in support of a manufacturing technology for diffusion bonding a beryllium armor tile to a copper alloy heat sink for fusion reactor applications. Because beryllium reacts with all but a few elements to form intermetallic compounds, this study considered several different surface treatments as a means of both inhibiting these reactions and promoting a good diffusion bond between the two substrates. All diffusion bonded assemblies used aluminum or an aluminum-beryllium composite (AlBeMet-150) as the interfacial material in contact with beryllium. In most cases, explosive bonding was utilized as a technique for joining the copper alloy heat sink to an aluminum or AlBeMet-150 substrate, which was subsequently diffusion bonded to an aluminum coated beryllium tile. In this approach, a 250 mu m thick titanium foil is used as a diffusion barrier between the copper and aluminum to prevent the formation of Cu-Al intermetallic phases. In all cases, a hot isostatic pressing (HIP) furnace was used in conjunction with canned assemblies in order to minimize oxidation and apply sufficient pressure on the assembly for excellent metal-to-metal contact and subsequent bonding. Several different processing schedules were evaluated during the course of this study; bonded assemblies were produced with up to 100% joint efficiency. At this writing, a beryllium-copper divertor mock-up has survived 1000 thermal cycles at 10 MW/m(2) without damage during testing at the electron beam test system (EBTS) facility at Sandia National Laboratory in New Mexico. C1 Sandia Natl Labs, Livermore, CA 94551 USA. RP Odegard, BC (reprint author), Sandia Natl Labs, POB 969, Livermore, CA 94551 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 896 EP 900 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300198 ER PT B AU Nygren, RE AF Nygren, RE GP IEEE IEEE IEEE TI A comparison of stresses in armor joints with and without interlayers SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Post-fabrication and operating stresses in heat sinks with a 1mm compliant layer (or no interlayer) between tungsten armor and a CuCrZr channel were analyzed with a 2-D finite element model with temperature dependent properties, generalized plane strain, and strain hardening. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Nygren, RE (reprint author), Sandia Natl Labs, POB 5800,MS1129, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 901 EP 905 PG 5 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300199 ER PT B AU Spampinato, PT Barry, RE Chesser, JB Menon, MM Dagher, MA Slotwinski, A AF Spampinato, PT Barry, RE Chesser, JB Menon, MM Dagher, MA Slotwinski, A GP IEEE IEEE IEEE TI A laser metrology/viewing system for ITER in-vessel inspection SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB This paper identifies the requirements for a remotely operated precision laser ranging system for the International Thermonuclear Experimental Reactor. The inspection system is used for metrology and viewing, and must be capable of achieving submillimeter accuracy and operation in a reactor vessel that has high gamma radiation, high vacuum, elevated temperature, and magnetic field levels, A coherent, frequency modulated laser radar system is under development to meet these requirements. The metrology/viewing sensor consists of a compact laser-optic module linked through fiberoptics to the laser source and imaging units, located outside the harsh environment. The deployment mechanism is a remotely operated telescopic mast. Gamma irradiation up to 10(7) Gy was conducted on critical sensor components with no significant impact to data transmission, and analysis indicates that critical sensor components can operate in a magnetic field with certain design modifications. Plans for testing key components in a magnetic field are underway. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Spampinato, PT (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 941 EP 944 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300208 ER PT B AU Menon, MM Grann, EB Slotwinski, A AF Menon, MM Grann, EB Slotwinski, A GP IEEE IEEE IEEE TI Radiation effects on optical components of a laser radar sensor designed for remote metrology in ITER SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB A frequency modulated laser radar is being developed for in-vessel metrology and viewing of plasma-facing surfaces. Some optical components of this sensor must withstand intense gamma radiation (3 x 10(6) rad/h) during operation. We have tested the effect of radiation on a silica core polarization maintaining optical fiber and on TeO2 crystals at doses rep to similar to 10(9) rad. Additional tests are planned for evaluating the performance of a complete acousto-optic (AO) scanning device. The progress made in these tests is also described. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Menon, MM (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 977 EP 980 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300217 ER PT B AU Reiersen, W Dahlgren, F Steiner, D Bonanos, P Bromberg, L Neumeyer, C Fan, HM AF Reiersen, W Dahlgren, F Steiner, D Bonanos, P Bromberg, L Neumeyer, C Fan, HM GP IEEE IEEE IEEE TI A comparative assessment of centerpost design options for ARIES-ST SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The ARIES team is presently assessing the feasibility of a low aspect ratio (LAR) or spherical tokamak (ST) to serve as a commercial power plant. Development of a credible design for the centerpost is one of the key feasibility issues. In this paper, centerpost design options are identified and systematically assessed. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Reiersen, W (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 1035 EP 1038 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300230 ER PT B AU Kamperschroer, JH Cropper, MB Grisham, LR McCormack, BE Nagy, A O'Connor, TE Oldaker, ME Stevenson, TN von Halle, A AF Kamperschroer, JH Cropper, MB Grisham, LR McCormack, BE Nagy, A O'Connor, TE Oldaker, ME Stevenson, TN von Halle, A GP IEEE IEEE IEEE TI Tritium consumption and retention in TFTR neutral beams SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB 750,000 Ci of tritium have passed through the TFTR neutral beamlines since December, 1993. During the course of 725 tritium heated discharges, 47,000 Ci have been extracted as ions from the ion sources and 27,000 Ci injected into TFTR as neutral atoms. Prior to the commencement of deuterium-tritium (DT) experiments, Los Alamos and Sandia National Laboratories made estimates of tritium retention in each beamline due to implantation in the 2 m(2) of copper beam absorbers and adsorption on the 250 m(2) of internal surface area. Their estimates were: 500 Ci embedded per beamline in beam absorbers after 1000 DT shots; and 100 Ci adsorbed per beamline after exposure to 1 ton of tritium for 1 hour. Both estimates were revised downward since the estimates assumed pure tritium operation, whereas the neutral beams used orders of magnitude more deuterium than tritium. Deuterium competes with tritium for implantation and adsorption sites, reducing the uptake of tritium relative to the use of pure tritium. Data from neutron detectors indicated that the quantity of tritium implanted is equivalent to the revised estimate. The amount of adsorbed tritium exceeds the prediction. While tritium operation was highly successful, there were problems with the failure of several ion sources and gas injectors. Ion source failures were not due to the use of tritium as the working gas. However, their removal yielded information regarding tritium retention. Ten tritium injectors failed during the three and a half years of tritium experiments; six were replaced. At the conclusion of TFTR operation, all working tritium injectors had throughput leaks. By comparison, the deuterium injectors, which used the same valves, had only two minor fill valve leaks, and no repairs were necessary. Tritium contaminated component removal required purging until the concentration of tritium in any released air was < 20 mu Ci/m(3). For ion source removal, this necessitated 50 to 100 purges and the release of several Ci. Upon removal, source surfaces had to be further decontaminated, from several million dpm/100 cm(2), to levels at which repairs could be effected. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kamperschroer, JH (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 1071 EP 1074 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300238 ER PT B AU Kamperschroer, JH Cropper, MB Grisham, LR McCormack, BE O'Connor, TE Oldaker, ME Stevenson, TN von Halle, A AF Kamperschroer, JH Cropper, MB Grisham, LR McCormack, BE O'Connor, TE Oldaker, ME Stevenson, TN von Halle, A GP IEEE IEEE IEEE TI Analysis of ion source arc chamber failure and grid damage sustained during high power operation SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Several ion sources failed during the last months of TFTR operation. Four suffered are chamber vacuum leaks which admitted SF6 into the source. One of these also had warped accelerator rails which resulted in damage to a water cooled scraper. The arc chamber leaks occurred at the boundary between the probe plate and either the bucket or interface plate. Vacuum seals at those locations consist of a mylar insulator sandwiched between two o-rings. At the failure point, the mylar had been punctured back to the o-ring. Are tracks were observed along the plasma facing surfaces of the probe plate and were funneled into every other gap between magnet. This evidence is suggestive of JxB forces driving the arcs toward the interface between the various plates and toward the o-ring. Damage is correlated with high are power and the failure to expeditiously extinguish the are. Operation with additional anode area is suggested as a means to avoid are creation. On the source with the warped grid rails, a section of a nearby scraper was melted. TFTR ion sources are masked down versions of the US Common Long Pulse Ion Source. Four rails on either end of the source are masked creating an ion beam that is similar to 43 cm tall. Rails under the mask were the most deformed (0.055" out of tolerance). Damage is believed to have occurred during 3 s pulses when 15 MJ were extracted over 3 s under slightly overdense conditions. The rails were deflected back towards the are chamber causing the edge beamlets to be directed away from the axis. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kamperschroer, JH (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 1075 EP 1078 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300239 ER PT B AU Kamperschroer, JH Garzotto, V Grisham, LR McCormack, BE O'Connor, TE Oldaker, ME Stevenson, TN von Halle, A AF Kamperschroer, JH Garzotto, V Grisham, LR McCormack, BE O'Connor, TE Oldaker, ME Stevenson, TN von Halle, A GP IEEE IEEE IEEE TI The TFTR neutral beam pulse length limit SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB Early operation of the TFTR long pulse ion sources identified the full-energy ion dump as the critical constraint for long pulse operation. Full power, two second operation resulted in severe stress cracking of this component. Subsequent to this discovery, the dumps on all beamlines were replaced and new operating procedures implemented that restricted the surface temperature to that consistent with 120 kV for 0.65 s. In November, 1996 the ion dump in a tritium contaminated beamline was remotely inspected. No new damage was observed and the pulse length limit was relaxed to allow 95 kV, 5 s operation in support of enhanced reversed shear experiments. Two techniques have been proposed and partly tested that reduce ion dump power densities and permit longer pulse lengths. These are: 1) rastering of the ion beam across the ion dump, and 2) a vertical adjustment of the impact point on the full-energy dump. The latter of these techniques has applicability to the proposed Korean tokamak, KSTAR, which is currently using the TPX beamline tan upgraded TFTR beamline) as the basis for its design. Rastering consists of moving the ion beam laterally across the dump, thereby increasing the heated area. Based on static rastering experiments, the power density reduction due to several rastering patterns have been modeled. A 40% decrease in power density is predicted. Technique #2 stems from the curved nature of the full-energy ion dump-ions from the outer two ion sources strike lower on the dump than do ions from the center source. A small increase in the magnetic field moves the impact point higher up on the ion dump and farther from the magnet's focal point. The result is a 20% reduction in power density. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Kamperschroer, JH (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 1079 EP 1082 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300240 ER PT B AU Combs, SK Baylor, LR Foust, CR Gouge, MJ Jernigan, TC Milora, SL AF Combs, SK Baylor, LR Foust, CR Gouge, MJ Jernigan, TC Milora, SL GP IEEE IEEE IEEE TI Experimental study of curved guide tubes for pellet injection SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB The use of curved guide tubes for transporting frozen hydrogen pellets offers great flexibility for pellet injection into plasma devices. While this technique has been previously employed, an increased interest in its applicability has been generated with the recent ASDEX Upgrade experimental data far magnetic high-field side (HFS) pellet injection. In these innovative experiments, the pellet penetration appeared to be significantly; deeper than for the standard magnetic low-field side injection scheme, along with corresponding greater fueling efficiencies. Thus, some of the major experimental fusion devices are planning experiments with HFS pellet injection. Because of the complex geometries of experimental fusion devices, installations with multiple curved guide tube sections will be required for HFS pellet injection. To more thoroughly understand and document the capability of curved guide tubes, an experimental study is under way at the Oak Ridge National Laboratory (ORNL). In particular, configurations and pellet parameters applicable for the DIII-D tokamak and the International Thermonuclear Experimental Reactor (ITER) were simulated in laboratory experiments. Initial test results with nominal 2.7- and 10-mm-diam deuterium pellets are presented and discussed. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Combs, SK (reprint author), Oak Ridge Natl Lab, POB 2009, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 1102 EP 1105 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300246 ER PT B AU Awad, MN Martin, WJ AF Awad, MN Martin, WJ GP IEEE IEEE IEEE TI Windage loss reduction study for TFTR pulse generator SO 17TH IEEE/NPSS SYMPOSIUM ON FUSION ENGINEERING, VOLS 1 AND 2 LA English DT Proceedings Paper CT 17th IEEE/NPSS Symposium on Fusion Engineering CY OCT 06-10, 1997 CL SAN DIEGO, CA SP IEEE, NPSS, Boeing Co, Lawrence Livermore Natl Lab, MIT, Sandia Natl Lab, Univ California San Diego, Univ Illinois AB In PPPL's campaign to Improve operating efficiency and reduce operating costs of our large vertical shaft motor generators proved to be a fruitful area. The measured losses In the stator air cooling loop were In the area of one megawatt.. Reducing these losses was the focus of a recent study by PPPL and GE Hydro. Operating data was used to calculate the load cycle temperature profile of the motor generator. Based on the wide margin between design limitation and operating profile, the estimated energy saving is about 200 KW per hour, cin optimum air velocity through the generator stator cooler was determined and means were developed to reduce the flow without compromising generator insulation limits. C1 Princeton Plasma Phys Lab, Princeton, NJ 08543 USA. RP Awad, MN (reprint author), Princeton Plasma Phys Lab, POB 451, Princeton, NJ 08543 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4226-7 PY 1998 BP 1125 EP 1128 PG 4 WC Engineering, Electrical & Electronic; Nuclear Science & Technology; Physics, Applied; Physics, Fluids & Plasmas SC Engineering; Nuclear Science & Technology; Physics GA BL48U UT WOS:000075681300251 ER PT S AU Vernon, SP Kearney, PA Tong, WM Prisbrey, S Larson, C Moore, CE Weber, FW Cardinale, G Yan, PY Hector, SD AF Vernon, SP Kearney, PA Tong, WM Prisbrey, S Larson, C Moore, CE Weber, FW Cardinale, G Yan, PY Hector, SD BE Grenon, BJ Abboud, FE TI Masks for extreme ultraviolet lithography SO 18TH ANNUAL SYMPOSIUM ON PHOTOMASK TECHNOLOGY AND MANAGEMENT SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th Annual BACUS Symposium on Photomask Technology and Management CY SEP 16-18, 1998 CL REDWOOD CITY, CA SP BACUS DE extreme ultraviolet lithography; masks; multilayers; defects; inspection; mask blanks ID RAY PROJECTION LITHOGRAPHY; REFLECTION AB In extreme ultraviolet lithography (EUVL), the technology specific requirements on the mask are a direct consequence of the utilization of radiation in the spectral region between 10 and 15 nm. At these wavelengths, all condensed materials are highly absorbing and efficient radiation transport mandates the use of all-reflective optical systems. Reflectivity is achieved with resonant, wavelength-matched multilayer (ML) coatings on all of the optical surfaces - including the mask. The EUV mask has a unique architecture - it consists of a substrate with a highly reflective ML coating (the mask blank) that is subsequently over-coated with a patterned absorber layer (the mask). Particulate contamination on the EUVL mask surface, errors in absorber definition and defects in the ML coating all have the potential to print in the lithographic process. While highly developed technologies exist for repair of the absorber layer, no viable strategy for the repair of ML coating defects has been identified. In this paper the state-of-the-art in ML deposition technology, optical inspection of EUVL mask blank defects and candidate absorber patterning approaches are reviewed. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Vernon, SP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 22 TC 16 Z9 16 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3007-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3546 BP 184 EP 193 DI 10.1117/12.332826 PG 10 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BM43T UT WOS:000078742500018 ER PT S AU Jeong, ST Idir, M Johnson, L Lin, Y Batson, P Levesque, R Kearney, P Yan, PY Gullikson, E Underwood, JH Bokor, J AF Jeong, ST Idir, M Johnson, L Lin, Y Batson, P Levesque, R Kearney, P Yan, PY Gullikson, E Underwood, JH Bokor, J BE Grenon, BJ Abboud, FE TI Actinic detection of EUVL mask blank defects SO 18TH ANNUAL SYMPOSIUM ON PHOTOMASK TECHNOLOGY AND MANAGEMENT SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th Annual BACUS Symposium on Photomask Technology and Management CY SEP 16-18, 1998 CL REDWOOD CITY, CA SP BACUS DE EUVL; mask; Mo/Si multilayer; printable defect AB We report the design and initial experimental results of an actinic inspection system for extreme ultraviolet lithography mask blank defect detection. Initial bright-field and dark-field results demonstrate sensitivity to submicron size phase defects. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. RP Jeong, ST (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Xray Opt, Berkeley, CA 94720 USA. NR 9 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3007-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3546 BP 524 EP 530 DI 10.1117/12.332865 PG 7 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BM43T UT WOS:000078742500055 ER PT S AU Spector, SJ White, DL Tennant, DM Luo, P Wood, OR AF Spector, SJ White, DL Tennant, DM Luo, P Wood, OR BE Grenon, BJ Abboud, FE TI Rapid at-wavelength inspection of EUV mask blanks by photoresist transfer SO 18TH ANNUAL SYMPOSIUM ON PHOTOMASK TECHNOLOGY AND MANAGEMENT SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT 18th Annual BACUS Symposium on Photomask Technology and Management CY SEP 16-18, 1998 CL REDWOOD CITY, CA SP BACUS DE extreme-ultraviolet; lithography; mask inspection; reflective masks AB We have developed a new technique for at-wavelength inspection of EUV mask blanks. In this technique a thin layer of EUV photoresist is applied directly to a mask blank which is then flood exposed with EUV light and partially developed. We have demonstrated using atomic force microscopy (AFM) that a change in reflectance of only 12% can cause a similar to 50 Angstrom mound in ZEP photoresist. We propose that such mounds could be detected by existing optical inspection tools, and have demonstrated the detection of similar features in ZEP (created using electron beam lithography) by an automated darkfield optical scanning instrument. The greatest advantage of the technique is speed, since both steps (EUV flood exposure and optical inspection) can be done rapidly. Difficulties, such as contamination and resist roughness, are discussed along with possible solutions. C1 Brookhaven Natl Lab, Bell Labs, Lucent Technol, Upton, NY 11973 USA. RP Spector, SJ (reprint author), Brookhaven Natl Lab, Bell Labs, Lucent Technol, Upton, NY 11973 USA. NR 11 TC 7 Z9 7 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-3007-2 J9 P SOC PHOTO-OPT INS PY 1998 VL 3546 BP 548 EP 555 DI 10.1117/12.332877 PG 8 WC Optics; Imaging Science & Photographic Technology SC Optics; Imaging Science & Photographic Technology GA BM43T UT WOS:000078742500058 ER PT B AU Biefeld, RM Allerman, AA Kurtz, SR Burkhart, JH AF Biefeld, RM Allerman, AA Kurtz, SR Burkhart, JH BE Melloch, M Reed, MA TI The growth of mid-infrared emitting InAsSb/InAsP strained-layer superlattices using metal-organic chemical vapor deposition SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB We describe the metal-organic chemical vapor deposition of InAsSb/InAsP strained-layer superlattice (SLS) active regions for use in mid-infrared emitters. These SLSs were grown at 500 degrees C, and 200 torr in a horizontal quartz reactor using trimethylindium, triethylantimony, AsH3, and PH3. By changing the layer thickness and composition we have prepared structures with low temperature (less than or equal to 20K) photoluminescence wavelengths ranging from 3.2 to 5.0 mu m. Excellent performance was observed for an SLS light emitting diode (LED) and both optically pumped and electrically injected SLS lasers. An InAsSb/InAsP SLS injection laser emitted at 3.3 mu m at 80 K with peak power of 100 mW. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Biefeld, RM (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 113 EP 116 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900026 ER PT B AU Jones, ED Blount, M Chow, W Hou, H Simmons, JA AF Jones, ED Blount, M Chow, W Hou, H Simmons, JA BE Melloch, M Reed, MA TI Bandgap renormalization studies of n-type GaAs/AlGaAs single quantum wells SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB Bandgap energy renormalization due to many body effects has been studied in a series of n-type 8-nm-wide GaAs/AlGaAs single quantum wells using magnetoluminescence spectroscopy at 1.4K. The 2D-carrier densities varied between 1 and 12 x 10(11) cm(-2). At the maximum 2D-carrier density, the bandgap energy reduction compared to an undoped specimen was found to be about 34 meV. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Jones, ED (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 187 EP 190 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900044 ER PT B AU Denecke, R Morais, J Liesegang, J Fadley, CS AF Denecke, R Morais, J Liesegang, J Fadley, CS BE Melloch, M Reed, MA TI X-ray photoelectron diffraction study of hexagonal GaN(0001) thin films SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB We report on the first scanned-angle x-ray photoelectron diffraction measurements on GaN(0001) in the wurtzite structure, as grown on sapphire substrates using LPCVD. These as-grown samples reveal forward scattering peaks in agreement with a theoretical calculation using a multiple scattering cluster calculation. From the combination of experiment and theoretical calculation and from a simple intensity ratio argument the surface polarity for these samples could be determined to be N. The surface contamination by O and C does not exhibit any clear structure. The data also indicate that C is on average closer to the GaN surface than O. C1 Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RP Denecke, R (reprint author), Lawrence Berkeley Natl Lab, Div Mat Sci, Berkeley, CA 94720 USA. RI Morais, Jonder/E-5022-2013 OI Morais, Jonder/0000-0002-4143-1208 NR 0 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 223 EP 226 DI 10.1109/ISCS.1998.711622 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900053 ER PT B AU Blount, MA Simmons, JA Lyo, SK Harff, NE Weckwerth, MV AF Blount, MA Simmons, JA Lyo, SK Harff, NE Weckwerth, MV BE Melloch, M Reed, MA TI Magnetoresistance and cyclotron mass in extremely-coupled double quantum wells under in-plane magnetic fields SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB We experimentally investigate the transport properties of an extremely-coupled AlGaAs/GaAs double quantum well, subject to in-plane magnetic fields (B-parallel to). The coupling of the double quantum well is sufficiently strong that the symmetric-antisymmetric energy gap (Delta(SAS)) is larger than the Fermi energy (E-F). Thus for all B-parallel to, only the lower energy branch of the dispersion curve is occupied. In contrast to systems with weaker coupling such that Delta(SAS) < E-F we find: (1) only a single feature, a maximum, in the in-plane magnetoresistance, (2) a monotonic increase with B-parallel to, in the cyclotron mass up to 2.2 times the bulk GaAs mass, and (3) an increasing Fermi surface orbit area with B-parallel to, in good agreement with theoretical predictions. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Blount, MA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 275 EP 278 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900065 ER PT B AU Kurtz, SR Allerman, AA Biefeld, RM Baucom, KC AF Kurtz, SR Allerman, AA Biefeld, RM Baucom, KC BE Melloch, M Reed, MA TI Multi-staged, InAsSb mid-infrared lasers and light-emitting diodes, grown by MOCVD SO 1997 IEEE INTERNATIONAL SYMPOSIUM ON COMPOUND SEMICONDUCTORS LA English DT Proceedings Paper CT 24th IEEE International Symposium on Compound Semiconductors CY SEP 08-11, 1997 CL SAN DIEGO, CA SP IEEE, Motorola, USN, Off Naval Res, Siemens, Aixtron, EPI AB We describe the first mid-infrared (4 mu m) lasers and LEDs utilizing strained InAsSb, multi-stage (or "cascaded) active regions. An (n)InAs/(p)GaAsSb semimetal layer is incorporated into each stage as an internal electron-hole source. To date, 2-stage LEDs and 2-stage lasers have been demonstrated. Our multi-stage devices were grown by MOCVD. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kurtz, SR (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-3883-9 PY 1998 BP 569 EP 572 PG 4 WC Engineering, Electrical & Electronic; Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Optics; Physics, Applied SC Engineering; Materials Science; Optics; Physics GA BL44M UT WOS:000075543900135 ER PT B AU Krieger, B Kipnis, I Ludewigt, BA AF Krieger, B Kipnis, I Ludewigt, BA BE Nalcioglu, O TI XPS: A multi-channel preamplifier-shaper IC for x-ray spectroscopy SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB An integrated circuit featuring 48 channels of charge-sensitive preamplifiers followed by variable-gain pulse shaping amplifiers is being developed as part of an x-ray spectrometer with a highly segmented detector to handle high fluxes in synchrotron experiments. Such detector systems can provide excellent energy resolution combined with one-dimensional spatial information. The IC provides preamplifier and shaping amplifier functions and its output stage is capable of driving conventional ADC modules directly. Reported here are first measurements made on the performance of a 16-channel prototype integrated circuit. At present, the preamplifier-shaper circuit achieves an equivalent input noise of 26 electrons rms at 2 mu s peaking time with a 0.2 pF external capacitor, which is similar to the capacitance of a single detector element. Pulse shaping is accomplished by a novel CR-RC2 filter section that utilizes several high-linearity transconductor circuits to provide a broad range of continuously variable peaking times while still maintaining the linearity and noise performance necessary for x-ray spectroscopy. The design was fabricated in standard 1.2 mu m CMOS technology.*. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Krieger, B (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 5 EP 7 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900002 ER PT B AU Li, Z Eremin, V Ilyashenko, I Ivanov, A Verbitskaya, E AF Li, Z Eremin, V Ilyashenko, I Ivanov, A Verbitskaya, E BE Nalcioglu, O TI Investigation of epitaxial silicon layers as a material for radiation hardened silicon detectors SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Epitaxial grown thick layers (>100 mu m) of high resistivity silicon (Epi-Si) have been investigated as a possible candidate of radiation hardened material for detectors for high-energy physics. As grown Epi-Si layers contain high concentration (up to 2.10(12) cm(-3)) of deep levels compared with that in standard high resistivity bulk Si. After irradiation of test diodes by protons (E-p = 24 GeV) with a fluence of 1.5.10(11) cm(-2), no additional radiation induced deep traps have been detected. A reasonable explanation is that there is a sink of primary radiation induced defects (interstitial and vacancies), possibly by as-grown defects, in epitaxial layers. The "sinking" process, however, becomes non-effective at high radiation fluences (10(14) cm(-2)) due to saturation of epitaxial defects by high concentration of radiation induced ones. As a result, at neutron fluence of 1.10(14)cm(-2) the deep level spectrum corresponds to well-known spectrum of radiation induced defects in high resistivity bulk Si. The net effective concentration in the space charge region equals to 3-10(12) cm(-3) after 3 months of room temperature storage and reveals similar annealing behavior for epitaxial as compared to bulk silicon. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Li, Z (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Verbitskaya, Elena/D-1521-2014 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 46 EP 50 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900011 ER PT B AU Koster, JE Bounds, JA Kerr, PL Steadman, PA Whitley, CR AF Koster, JE Bounds, JA Kerr, PL Steadman, PA Whitley, CR BE Nalcioglu, O TI Whole body personnel monitoring via ionization detection SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A project between Fernald EMP and LANL is to field a monitor for the detection of alpha-emitting contamination on a human body. Traditional personnel monitoring for alpha emitters involves either frisking with a probe or pressing against large detectors in order to overcome the short range of alpha particles. These methods have a low alpha collection efficiency, and can miss contamination on less accessible surfaces. We have investigated the sensitivity and practicality of measuring the entire subject simultaneously using the technique of ionization monitoring. The goal is to create a booth that personnel step into quickly during egress from radiological facilities. The detection technique relies on a breeze of air passing over the subject. Alpha emission produces copious ions In the ambient air which are transported by the air current to an ion collector, resulting in a small electrical current proportional to the amount of contamination. Results indicate a conservative sensitivity of 3000 disintegrations per minute localized to one of five areas of the body in a measurement lasting less than 2 minutes. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Koster, JE (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 57 EP 61 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900013 ER PT B AU Kerr, PL Koster, JE Conaway, JG Bounds, JA Steadman, PA Whitley, CW AF Kerr, PL Koster, JE Conaway, JG Bounds, JA Steadman, PA Whitley, CW BE Nalcioglu, O TI Monitoring airborne alpha-emitter contamination SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Facilities that may produce airborne alpha-emitter contamination require a continuous air monitoring (CAM) system. However, these traditional CAMs have difficulty in environments with large quantities of non-radioactive particulates such as dust and salt. Los Alamos has developed an airborne-plutonium sensor (APS) for the REBOUND experiment at the Nevada Test Site which detects alpha contamination directly in the air, and so is less vulnerable to the problems associated with counting activity on a filter. In addition, radon compensation is built into the detector by the use of two measurement chambers. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Kerr, PL (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 62 EP 67 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900014 ER PT B AU Whitley, CR Bounds, JA Steadman, PA AF Whitley, CR Bounds, JA Steadman, PA BE Nalcioglu, O TI Portable swipe monitor for alpha contamination SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A portable swipe monitor has been developed at Los Alamos National Laboratory for the state of New Mexico. The monitor is intended for use at New Mexico ports of entry to detect removable alpha contamination on shipments bound for the proposed Waste Isolation Pilot Plant (WIPP). This detector uses Long-Range Alpha Detection (LRAD) technology, which monitors ionization created by alpha interactions with ambient air, and includes built-in background subtraction of external radiation fields and radon. Its sensitivity to alpha contamination is on the order of a few tens of dpm, and it has excellent linearity throughout its entire range of over 200,000 counts per minute of alpha activity. Designed to be used primarily in the field, the monitor is battery-powered and can operate continuously for up to five hours. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Whitley, CR (reprint author), Univ Calif Los Alamos Natl Lab, MS J-561, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 68 EP 70 PG 3 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900015 ER PT B AU Ericson, MN Allen, MD Boissevain, J Britton, CL Emery, MS Hahn, SF Kapustinsky, JS Lind, RE Musrock, MS Simon-Gillo, J Smith, DE Sullivan, JP Van Hecke, H Young, GR AF Ericson, MN Allen, MD Boissevain, J Britton, CL Emery, MS Hahn, SF Kapustinsky, JS Lind, RE Musrock, MS Simon-Gillo, J Smith, DE Sullivan, JP Van Hecke, H Young, GR BE Nalcioglu, O TI Front-end module readout and control electronics for the PHENIX multiplicity vertex detector SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Front-end module (FEM) readout and control are implemented as modular, high-density, reprogrammable functions in the PHENIX Multiplicity Vertex Detector. FEM control is performed by the heap manager, an FPGA-based circuit in the FEM unit. Each FEM has 256 channels of front-end electronics, readout, and control, all located on an MCM. Data readout, formatting, and control are performed by the heap manager along with 4 interface units that reside outside the MVD detector cylinder. This paper discusses the application of a generic heap manager and the addition of 4 interface module types to meet the specific control and data readout needs of the MVD. Unit functioning, interfaces, timing, data format, and communication rates will be discussed in detail. In addition, subsystem issues regarding mode control, serial architecture and functions, error handling, and FPGA implementation and programming will be presented. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ericson, MN (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 140 EP 144 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900030 ER PT B AU Burks, M Beuville, E Cwetanski, P Retiere, F Smirnov, N Trentalange, S Wieman, H AF Burks, M Beuville, E Cwetanski, P Retiere, F Smirnov, N Trentalange, S Wieman, H BE Nalcioglu, O TI Integrated gas microstrip and microgap chambers for a MicroTPC vertex detector SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Readout devices are being developed for use in a gas based vertex detector called the MicroTPC. The readout devices will consist of either integrated microstrip or microgap detectors. These devices are unique in that they have the detector fabricated directly onto the silicon with the preamplifier and shaper electronics. This offers lower noise and higher channel density compared to conventional microstrip design. Both devices were fabricated at Hewlett Packard using a standard 0.8 mu m,3 metal process. Integrated gas microstrip detectors have been tested and an energy resolution of 18% FWHM, an electronics noise of 80 e(-) r.m.s. and a gas gain of 200 was achieved. Integrated gas microgap detectors have also been fabricated and tested but only limited success has been achieved in comparison to the microstrip detectors. These devices, in conjunction with a low mass, high resolution MicroTPC should make a vertex detector well suited for heavy-ion physics environments such as RHIC and the LHC. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Burks, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 159 EP 163 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900034 ER PT B AU Derenzo, SE Weber, MJ AF Derenzo, SE Weber, MJ BE Nalcioglu, O TI Ab-initio cluster calculations of hole transport and activator excitation in CsI : Tl and CsI : Na SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB We describe methods for using Gausian94 (an ab-initio molecular orbital program) to compute energies and electron distributions that describe (1) the formation and transport of holes in the crystal CsI and (2) the electronic nature of the lowest excited states of CsI, CsI:Tl and CsI:Na. To model these processes, the Schrodinger equation was solved at the Hartree-Fock level (in some cases with Moller-Plesset second-order electron correlation corrections) for clusters ranging in size from of 12 Cs and 12 I atoms to 16 Cs and 29 I atoms in an electrostatic field generated by approximately 5800 point charges. The calculations show that(1)a relaxed hole in CsI is shared equally by two I atoms (classic V-k center) bound by an energy of 0.85 eV; (2) the energy barrier for the motion of the hole is 0.15 eV and the transition state consists of the hole on a single I atom; (3) the lowest excited state of Cs12I12 is a V-k center plus a diffuse electron in the Rydberg states of the other ions (an exciton); (4) the lowest excited state of the cluster NaCs13I14 is an exciton whose energy is lowered by the presence of the Na atom; and (5) the lowest excited state of the cluster TlCs13I14 is an excited Tl atom with all Cs and I electrons in their ground states. We believe that it is now computationally possible to model hole transport and electronic excitation in a variety of compounds to guide the search for new scintillators. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Derenzo, SE (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 164 EP 168 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900035 ER PT B AU Pengg, F AF Pengg, F BE Nalcioglu, O TI Pixel detector readout electronics with two-level discriminator scheme SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB In preparation for a silicon pixel detector with more than 3000 readout channels per chip for operation at the future large hadron collider LHC at CERN the analog frontend of the readout electronics has been designed and measured on several test arrays with 16 by 4 cells. They are implemented in the HP 0.8 mu m process but compatible with the design rules of the radiation hard Honeywell 0.8 mu m bulk process. They contain bump bonding pad, preamplifier, discriminator and control logic for masking and testing in each cell. The layout area is only 50 mu m by 140 mu m per cell. A new two-level discriminator scheme has been developped to solve the problems of time-walk and interpixel cross-coupling. The measured gain of the preamplifier is 900mV per minimum ionizing particle (MIP, about 24000 e(-)) with a return to baseline within 750ns for a 1MIP input signal. The full readout chain shows an equivalent noise charge of 60e(-) r.m.s.. The time-walk is a function of the separation between the two threshold levels. With a separation of 1500e(-) a time-walk of 22ns is measured. The interpixel cross-coupling is measured as less than 3%. A single cell is operated with 35 mu W power consumption at 3.5V supply voltage. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Pengg, F (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 184 EP 188 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900039 ER PT B AU Paulus, MJ Uckan, T Lenarduzzi, R March-Leuba, J Castleberry, K Mattingly, JK Mihalczo, JT Mullens, JA Valentine, TE McEvers, JA AF Paulus, MJ Uckan, T Lenarduzzi, R March-Leuba, J Castleberry, K Mattingly, JK Mihalczo, JT Mullens, JA Valentine, TE McEvers, JA BE Nalcioglu, O TI Detector system for monitoring fissile mass flow in liquids and gasses SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A computer controlled detector/electronics module has been designed and constructed for the Oak Ridge National Laboratory fissile mass flow (FMF) monitor. The FMF monitor employs a host computer, a modulated neutron source (Cf-252) and four of the gamma-ray detector/electronics modules described here to non-intrusively measure liquid or gas fissile-mass-flow rates in a pipe. The gamma-ray detector/electronics modules each consist of a bismuth germanate/photomultiplier- tube scintillation detector, an integrating preamplifier, a bipolar spectroscopy amplifier, two single channel analyzers, a temperature sensor and an onboard network communications node. The host computer automatically calibrates amplifier gain and single-channel analyzer thresholds via the network using a characteristic emission peak of the material flowing in the pipe and corrects for detector gain variations due to the temperature coefficients of the bismuth germanate. The single channel analyzer output pulses are counted by a microprocessor on board the network node and reported to the host computer. The key components of the detector/electronics module are described and initial data obtained with the FMF monitor are presented. C1 Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37830 USA. RP Paulus, MJ (reprint author), Oak Ridge Natl Lab, Div Instrumentat & Controls, POB 2008, Oak Ridge, TN 37830 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 197 EP 200 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900042 ER PT B AU Reeder, PL Bowyer, TW AF Reeder, PL Bowyer, TW BE Nalcioglu, O TI High sensitivity detection of Xe-133g via delayed coincidence counting SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Sensitive detection of Xe fission products is needed for monitoring the Comprehensive Test Ban Treaty. Pacific Northwest National Laboratory has developed an automated system for separating Xe from air which includes a beta-gamma counting system for Xe-131m, Xe-133g, Xe-133m, and Xe-135g. Even greater sensitivity for Xe-133g can be achieved by use of the delayed coincidence between beta particles which feed the 81-keV state in Cs-133 and the conversion electrons produced in the deexcitation of the 81-keV state (t(1/2) = 6.36 ns). Besides the ability to detect Xe-133g with 0 background, this technique distinguishes Xe-133g from Xe-131m and Xe-133m. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Reeder, PL (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 201 EP 205 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900043 ER PT B AU Wojcik, R Majewski, S Kross, B Steinbach, D Weisenberger, AG AF Wojcik, R Majewski, S Kross, B Steinbach, D Weisenberger, AG BE Nalcioglu, O TI High spatial resolution gamma imaging detector based on a 5 '' diameter R3292 Hamamatsu PSPMT SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB High resolution imaging gamma-ray detectors were developed using Hamamatsu's 5 " diameter R3292 position sensitive PMT (PSPMT) [1] and a variety of crystal scintillator arrays. Special readout techniques were used to maximize the active imaging area while reducing the number of readout channels. Spatial resolutions approaching 1 mm were obtained in a broad energy range from 20 to 511 keV. Results are also presented of coupling the scintillator arrays to the PMT via imaging light guides consisting of acrylic optical fibers which enables greater design freedom. C1 Jefferson Lab, Newport News, VA 23606 USA. RP Wojcik, R (reprint author), Jefferson Lab, 12000 Jefferson Ave, Newport News, VA 23606 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 221 EP 225 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900047 ER PT B AU Britton, CL Ericson, MN Frank, SS Moore, JA Simpson, ML Young, GR Smith, RS Clonts, LG Parakkat, TB Boissevain, J Hahn, S Kapustinsky, JS Simon-Gillo, J Sullivan, JP van Hecke, H AF Britton, CL Ericson, MN Frank, SS Moore, JA Simpson, ML Young, GR Smith, RS Clonts, LG Parakkat, TB Boissevain, J Hahn, S Kapustinsky, JS Simon-Gillo, J Sullivan, JP van Hecke, H BE Nalcioglu, O TI TGV32: A 32-channel preamplifier chip for the multiplicity vertex detector at PHENIX SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB The TGV32, a 32-channel preamplifier-multiplicity discriminator chip for the Multiplicity Vertex Detector (MVD) at PHENIX, is a unique silicon preamplifier in that it provides both an analog output for storage in an analog memory and a weighted summed-current output for conversion to a channel multiplicity count. The architecture and test results of the chip are presented. Details about the design of the preamplifier, discriminator, and programmable digital-analog converters (DACs) performance as well as the process variations are presented. The chip is fabricated in a 1.2-mu m, n-well, CMOS process. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Britton, CL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 231 EP 235 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900049 ER PT B AU Bryan, WL Jagadish, U Britton, CL Frank, SS Ericson, MN Simpson, ML Young, GR Clonts, LG Smith, RS Oskarsson, A Mark, T Obrien, E Greene, V AF Bryan, WL Jagadish, U Britton, CL Frank, SS Ericson, MN Simpson, ML Young, GR Clonts, LG Smith, RS Oskarsson, A Mark, T Obrien, E Greene, V BE Nalcioglu, O TI TGLD: A 16 channel charge readout chip for the PHENIX pad chamber detector subsystem at RHIC SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB This paper describes the PHENIX Pad Chamber (PC) subsystem charge readout chip, TOLD. Due to the PC's high channel density, the TGLD and associated circuitry operate within the active detector region as permanent, zero access components during PHENIX operation and implement remote set-up, test and operation. Since the PC detector consists of three subassemblies (PC1, PC2 and PC3) that detect particles at three different distances fi om the PHENIX collision vertex, the TGLD design accommodates varying pad capacitance and charge gain for PCI, PC2 and PC3 and provides adjustable discrimination thresholds from MIP/10 to 2 MIP (Minimum Ionizing Particle). Operation with a complimentary digital memory unit (DMU) to form low power, low mass, readout cards is described. Partitioning of readout electronics and address control for robust PC operation are discussed. Component and system test results are reported. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Bryan, WL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Simpson, Michael/A-8410-2011 OI Simpson, Michael/0000-0002-3933-3457 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 236 EP 239 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900050 ER PT B AU Wintenberg, AL Moscone, CG Jones, JP Young, GR AF Wintenberg, AL Moscone, CG Jones, JP Young, GR BE Nalcioglu, O TI A CMOS integrating amplifier for the PHENIX ring imaging cherenkov detector SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A CMOS integrating amplifier has been developed for use in the PHENIX Ring Imaging Cherenkov (RICH) detector. The amplifier, consisting of a charge-integrating amplifier followed by a variable gain amplifier (VGA), is an element of a photon measurement system comprising a photomultiplier tube, a wideband, gain-of-10 amplifier, the integrating amplifier, and an analog memory followed by an ADC and double correlated sampling implemented in software. The integrating amplifier is designed for a nominal full scale input of 160 pC with a gain of 20 mV/pC and a dynamic range of 1000:1. The VGA is used for equalizing gains prior to forming analog sums for trigger purposes. The gain of the VGA is variable over a 3:1 range using a 5-bit digital control, and the risetime is held to approximately 20 ns using switched compensation in the VGA. Details of the design and results from several prototype devices fabricated in 1.2 mu m Orbit CMOS are presented. A complete noise analysis of the integrating amplifier and the correlated sampling process is included as well as a comparison of calculated, simulated and measured results. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Wintenberg, AL (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 244 EP 248 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900052 ER PT B AU David, G Kistenev, E Stoll, S White, S Woody, C Bazilevsky, A Belikov, S Chernichenkov, S Denisov, A Gilitzky, Y Kochetkov, V Melnikov, Y Onuchin, V Semenov, A Shelikhov, V Soldatov, A AF David, G Kistenev, E Stoll, S White, S Woody, C Bazilevsky, A Belikov, S Chernichenkov, S Denisov, A Gilitzky, Y Kochetkov, V Melnikov, Y Onuchin, V Semenov, A Shelikhov, V Soldatov, A BE Nalcioglu, O TI The calibration and monitoring system for the PHENIX lead-scintillator electromagnetic calorimeter SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB The calibration and monitoring system for the PHENIX lead-scintillator electromagnetic calorimeter is described along with the experience obtained in using this system to calibrate calorimeter modules with cosmic rays. The system is based on a UV laser which delivers light to each module through a series of optical fibers and splitters that is monitored at various points using silicon and vacuum photodiodes. Results are given from a prototype system based on a nitrogen laser which was used to monitor the stability of several modules, as well as to set the gains of the phototubes and establish the energy calibration of all calorimeter modules before installation into the final detector. A description of the final system to be used in PHENIX, based on a high power YAG laser, is also given. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP David, G (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. RI Soldatov, Anatoly/O-1797-2013 OI Soldatov, Anatoly/0000-0002-0682-1219 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 376 EP 380 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900080 ER PT B AU Paulus, MJ Mihalczo, JT Valentine, TE Mullens, JA Breeding, JE Uckan, T Mattingly, J Turner, G Smith, MC McEvers, JA AF Paulus, MJ Mihalczo, JT Valentine, TE Mullens, JA Breeding, JE Uckan, T Mattingly, J Turner, G Smith, MC McEvers, JA BE Nalcioglu, O TI A novel method for determining pulse counting circuitry dead time using the Nuclear Weapons Inspection System SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A novel method for measuring dead time in nuclear pulse processing circuitry has been developed using the autocorrelation measurement capability of the Nuclear Weapons Inspection System(NWIS). Initially developed for active neutron interrogation of nuclear weapons and other fissile assemblies, NWIS employs a custom gallium arsenide application specific integrated circuit and a new signature analysis software package to simultaneously acquire and display the autocorrelation and cross-correlation spectra of up to five detector/electronics systems. The system operates at clock frequencies up to I GHZ, permitting the collection of timing pulses in bins as narrow as I ns. In normal operation NWIS uses well characterized detectors and constant fraction discriminators, but it may also be configured to accept pulses from any circuit and to use the autocorrelation spectrum to accurately determine dead-time. Unlike traditional dead-time assessment techniques that typically require multiple sources and an assumed dead-time model, NWIS provides single-measurement assessment of circuit dead time and does not require an assumed dead-time model or a calibrated high count-rate source. C1 Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37830 USA. RP Paulus, MJ (reprint author), Oak Ridge Natl Lab, Div Instrumentat & Controls, POB 2008, Oak Ridge, TN 37830 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 462 EP 466 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900098 ER PT B AU Amman, M Beaulieu, L Hong, WS Phair, L Walton, JT Wozniak, GJ AF Amman, M Beaulieu, L Hong, WS Phair, L Walton, JT Wozniak, GJ BE Nalcioglu, O TI Heavy ion response of amorphous silicon transmission detectors for particle identification SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB In an effort to determine the applicability of a-Si:H transmission detectors to integrated Delta E-E detector telescopes, we have measured the response of discrete a-Si:H detectors to ions with atomic numbers between 7 and 36 and ranging in energy from 0.5 to 4.5 MeV/nucleon. Measured pulse height spectra show substantial pulse height deficits which depend on detector bias. Additionally an unexpected result is obtained in that the amplitudes of the detector signals correlate better with the total ion energy than with the ion energy loss in the transmission detector. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Amman, M (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 474 EP 478 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900101 ER PT B AU Bellwied, R Beuttenmuller, R Chen, W DiMassimo, D Dou, L Dyke, H French, A Hall, JR Hoffmann, GW Humanic, TJ Kotov, IV Kraner, HW Li, Z Liaw, CJ Lopez, J Lynn, D Rykov, VL Pandey, SU Pruneau, C Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Wilson, WK AF Bellwied, R Beuttenmuller, R Chen, W DiMassimo, D Dou, L Dyke, H French, A Hall, JR Hoffmann, GW Humanic, TJ Kotov, IV Kraner, HW Li, Z Liaw, CJ Lopez, J Lynn, D Rykov, VL Pandey, SU Pruneau, C Schambach, J Sedlmeir, J Sugarbaker, E Takahashi, J Wilson, WK BE Nalcioglu, O TI Anode region design and focusing properties of STAR Silicon Drift Detectors SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Electron collection at the anodes of large-area silicon drift detectors was studied with STAR2 prototypes. Results of measurements of anode leakage currents, signal dependence on focusing voltages, anode uniformity, and model simulations are reported. A design of the anode region is presented. The design optimization is discussed. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kotov, IV (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 510 EP 515 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900109 ER PT B AU Emery, MS Ericson, MN Britton, CL Smith, MC Frank, SS Young, GR Allen, MD Clonts, LG AF Emery, MS Ericson, MN Britton, CL Smith, MC Frank, SS Young, GR Allen, MD Clonts, LG BE Nalcioglu, O TI Timing and control requirements for a 32-channel AMU-ADC ASIC for the PHENIX detector SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A custom CMOS Application Specific Integrated Circuit (ASIC) has been developed consisting of an analog memory unit (AMU) and analog to digital converter (ADC), both of which have been designed for applications in the PHENIX experiment. This IC consists of 32 pipes of analog memory with 64 cells per pipe. Each pipe also has its own ADC channel. Timing and control signal requirements for optimum performance are discussed in this paper. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Emery, MS (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 651 EP 655 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900140 ER PT B AU Ericson, MN Frank, SS Britton, CL Emery, MS Sam, JS Wintenberg, AL AF Ericson, MN Frank, SS Britton, CL Emery, MS Sam, JS Wintenberg, AL BE Nalcioglu, O TI A configurable CMOS voltage DAC for multichannel detector systems SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A CMOS voltage DAC has been developed for integration into multiple front-end electronics ASICs associated with the PHENIX detector located at the RHIC accelerator of Brookhaven National Laboratory. The topology allows wide-range output programmability by selection of an offset voltage and on-chip resistor and transistor sizing. The DAC is trimless and requires no external components, making it ideal for highly integrated collider detector systems. Errors associated with on-chip bias are minimized using a topology that implements a ratiometric relationship which compensates for absolute resistance value changes and is limited only by errors in the on-chip matching of MOSFETs and resistive devices. Temperature-induced errors associated with the integrated resistors are also minimized by the circuit topology and monolithic construction. All reference voltages and currents are derived using a single regulated voltage supply. This paper presents the general DAC architecture and design method, discusses on-chip matching issues and tradeoffs associated with device sizing and monolithic layout, and presents measured performance of various gate length DACs fabricated in a 1.2 mu m CMOS process including integral nonlinearity, differential nonlinearity, and slope and offset errors. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Ericson, MN (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 671 EP 674 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900144 ER PT B AU Frank, SS Britton, CL Wintenberg, AL Young, GR AF Frank, SS Britton, CL Wintenberg, AL Young, GR BE Nalcioglu, O TI Trigger circuits for the PHENIX electromagnetic calorimeter SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Monolithic and discrete circuits have been developed to provide trigger signals for the PHENIX electromagnetic calorimeter detector. These trigger circuits are deadtimeless and create overlapping 4 by 4 energy sums, a cosmic muon trigger, and a 144 channel energy sum. The front end electronics of the PHENIX system sample the energy and timing channels at each bunch crossing (BC) but it is not known immediately if this data is of interest. The information from the trigger circuits is used to determine if the data collected is of interest and should be digitized and stored or discarded. This paper presents details of the design, issues affecting circuit performance, characterization of prototypes fabricated in 1.2 mu m Orbit CMOS, and integration of the circuits into the EMCal electronics system. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Frank, SS (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 680 EP 684 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900146 ER PT B AU McKinnon, AD Hubbard, CW AF McKinnon, AD Hubbard, CW BE Nalcioglu, O TI Data communications and management of a distributed network of automated data acquisition and analysis systems SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Several research applications require the deployment of a distributed network of automated data acquisition and analysis systems. These systems must provide a reliable and robust method of transferring acquired data to an appropriate data center. The data center must be capable of forwarding the acquired data to a potentially large group of researchers. The network's system operators need robust tools that allow them to easily manage and verify the state of health of the individual systems within the data acquisition and analysis network. Research at PNNL on automated radionuclide systems for the Comprehensive Nuclear Test Ban Treaty has shown that existing Internet protocols and software applications can be leveraged in the deployment of a functioning network of automated data acquisition and analysis systems. Specifically e-mail, FTP, and network news can be used to transmit data, while SNMP based management tools can be used to manage the systems within the network. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP McKinnon, AD (reprint author), Pacific NW Natl Lab, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 730 EP 733 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900159 ER PT B AU Ronan, M Kirkby, D Johnson, AS de Groot, N AF Ronan, M Kirkby, D Johnson, AS de Groot, N BE Nalcioglu, O TI Java online monitoring framework SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB An online monitoring framework has been written in the Java Language Environment to develop applications for monitoring special purpose detectors during commissioning of the PEP-II Interaction Region. PER-II machine parameters and signals from several of the commissioning detectors are logged through VxWorks/EPICS and displayed by Java display applications. Remote clients are able to monitor the machine and detector performance using graphical displays and analysis histogram packages. In this paper, the design and implementation of the object-oriented Java framework is described. Illustrations of data acquisition, display and histograming applications are also given. C1 Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Ronan, M (reprint author), Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI de Groot, Nicolo/A-2675-2009 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 734 EP 738 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900160 ER PT B AU Mahler, GJ Yu, B Smith, GC Kane, WR Lemley, JR AF Mahler, GJ Yu, B Smith, GC Kane, WR Lemley, JR BE Nalcioglu, O TI A portable gamma-ray spectrometer using compressed xenon SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB An ionization chamber using compressed xenon has been designed and built for gamma-ray spectrometry. The device is based on signal measurement from a parallel plate detector, with the gas enclosure constructed specifically for packaging into a portable instrument; thus, appropriate engineering practices using ASME codes have been followed. The portable system comprises two small containers that can be setup for operation in just a few minutes. Its sensitivity is 100 keV to over 1 MeV, with a resolution at 662 keV of 2.5% FWHM for uniform irradiation, and 2% FWHM for collimated irradiation, comparable to the best ever with compressed xenon. It also exhibits greater specificity than most scintillators, such as NaI. The device is insensitive to neutron damage and has a low power requirement. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Mahler, GJ (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 769 EP 773 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900169 ER PT B AU Rawool-Sullivan, MW Estep, RJ Miko, D AF Rawool-Sullivan, MW Estep, RJ Miko, D BE Nalcioglu, O TI Estimation of obliquely scattered gamma-ray response functions in the gross-count tomographic gamma scanner (GC-TGS) method SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB It was recently shown that a logarithmic response-function technique based on the material basis set (MBS) formalism used in the tomographic gamma scanner (TGS) method allows gross spectra from NaI detectors to be used in both measuring MBS transmission corrections using external transmission sources and in applying the corrections to emission spectra to arrive at radionuclide mass estimates. In this work we have attempted to show that addition of the oblique scatter component can increase the accuracy of the GC-TGS measurements with both NaI and high-purity germanium detectors. This paper describes the formalism behind the GC-TGS method and the improvement achieved in the analysis by including the scatter component. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Rawool-Sullivan, MW (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87545 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 774 EP 778 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900170 ER PT B AU Miley, HS Bowyer, SM Hubbard, CW McKinnon, AD Perkins, RW Thompson, RC Warner, RA AF Miley, HS Bowyer, SM Hubbard, CW McKinnon, AD Perkins, RW Thompson, RC Warner, RA BE Nalcioglu, O TI Automated aerosol sampling and analysis for the Comprehensive Test Ban Treaty SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Detecting nuclear debris from a nuclear weapon exploded in or substantially vented to the Earth's atmosphere constitutes the most certain indication that a violation of the Comprehensive Test Ban Treaty has occurred. For this reason, a radionuclide portion of the International Monitoring System is being designed and implemented. The IMS will monitor aerosols and gaseous xenon isotopes to detect atmospheric and underground tests, respectively. The monitoring network will be composed of a number of manual or automatic stations which have the capacity to sample large volumes of air each day and make sensitive gamma-ray spectroscopy measurements of the samples collected. In addition, a number of Certified Laboratories will perform confirmatory measurements on samples that show detectable quantities of fission products. This may be accomplished by measuring (instrumentally or by radiochemical means) certain isotopes which discriminate weapons debris from reactor accidents and other releases of fission products. An automated system, the Radionuclide Aerosol Sampler/Analyzer (RASA), has been developed at Pacific Northwest National Laboratory to meet CTBT aerosol measurement requirements. This is achieved by the use of a novel sampling apparatus, a high-resolution germanium detector, and very sophisticated software. This system draws a large volume of air (similar to 20,000 m(3)/day), performs automated gamma-ray spectral measurements (MDC(Ba-140) < 30 mu Bq/m(3)), and communicates this and other data to a central data facility. Automated systems offer the added benefit of rigid controls, easily implemented QA/QC procedures, and centralized depot maintenance and operation. Other types of automated communication include pull or push transmission of State-Of-Health data, commands, and configuration data. In addition, a graphical user interface, Telnet, and other interactive communications are supported over ordinary phone or network lines. This system has been the subject of a USAF commercialization effort to meet US CTBT monitoring commitments. It will also be available to other CTBT signatories and the monitoring community for various governmental, environmental, or commercial needs. The current status of the commercialization will be discussed. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Miley, HS (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 779 EP 785 PG 7 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900171 ER PT B AU Chen, W Eremin, V Li, Z Menichelli, D Wang, Q Zhao, L Chien, CY Xie, X Anderson, D Kwan, S AF Chen, W Eremin, V Li, Z Menichelli, D Wang, Q Zhao, L Chien, CY Xie, X Anderson, D Kwan, S BE Nalcioglu, O TI Design and processing of various configurations of silicon pixel detectors for high irradiation tolerance up to 6x10(14) n/cm(2) in LHC application SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Various new configurations of silicon pixel detector have been designed and are in prototype production. The material selection and detector design are aimed to production silicon detectors with radiation tolerance up to 6x10(14) n/cm(2) (or 4x10(14) pi/cm(2)) in LHC environment, which corresponds to a net increase (with long term anneal) of space charge of about 4.2x10(13) cm(-3). The configuration of n(+)/n/p(+), with multi-guard-rings structure for high voltage (up to 300 volts) operation, has been used for the purpose to make the detector insensitive to space charge sign inversion. The material selection of medium resistivity (1.9k Omega-cm) n-type silicon has been made to try a new solution in extending detector lifetime: it should be the first step toward the use of low resistivity silicon, to prevent type inversion. The traditional configuration of p(+)/n/n(+), with multi-guard-ring structure and high resistivity (4-6k Omega-cm) n-type material, has also been used with the same layout, to get a comparison. It is shown as the fabrication of n(+)/n/p(+) pixel detectors requires eight mask steps, while just four mask steps are required for the p(+)/n/n(+) configuration. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Chen, W (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 882 EP 886 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900195 ER PT B AU Landis, DA Madden, NW Goulding, FS AF Landis, DA Madden, NW Goulding, FS BE Nalcioglu, O TI Bipolar pulsed reset for AC coupled charge-sensitive preamplifiers SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A new type of charge restoration is described for use particularly in germanium gamma-ray spectrometers for accelerator and space physics applications. A bipolar pulsed reset technique is applied to these applications for the first time. This technique overcomes the problems introduced by the need here to AC couple detectors and the fact that very large energy depositions occur due to charged particles present in substantial fluxes, particularly in space. The circuit is described and experimental results are presented and discussed. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Engn, Dept Engn Sci,Measurement Sci Grp, Berkeley, CA 94720 USA. RP Landis, DA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Engn, Dept Engn Sci,Measurement Sci Grp, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 887 EP 891 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900196 ER PT B AU Kueck, JD Nicely, GH Chiloyan, J Leake, HC Sims, TR Trehan, N Attarian, G Baxter, F AF Kueck, JD Nicely, GH Chiloyan, J Leake, HC Sims, TR Trehan, N Attarian, G Baxter, F BE Nalcioglu, O TI A discussion of degraded voltage relaying for nuclear generating stations SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Nuclear generating stations utilize degraded voltage relaying schemes to protect electrical equipment against sustained low voltage conditions, Typical design involves the use of degraded voltage relays (DVRs) which, when actuated, automatically disconnect the safety buses from the degraded offsite power source and initiate reconnection to an alternate source such as the diesel generator. Although the industry recognizes the importance of ensuring that adequate voltage is supplied to critical plant equipment, the method of achieving this goal is a matter of ongoing discussion, Arguments are presented for and against automatic disconnection of the power source when a degraded voltage condition is sensed by the DVRs. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Kueck, JD (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 921 EP 926 PG 6 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900203 ER PT B AU Weisenberger, AG Kross, B Majewski, S Wojick Bradley, EL Saha, MS AF Weisenberger, AG Kross, B Majewski, S Wojick Bradley, EL Saha, MS BE Nalcioglu, O TI Design features and performance of a CsI(Na) array based gamma camera for small animal gene research SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB We report on the development of a radiation imaging system based on a matrix of CsI(Na) scintillating crystals. This detector system has been optimized for high resolution radiation imaging of the distribution of iodine 125 (I-125) in,, laboratory animal. The radioisotope I-125 is readily available as a label to molecular biology probes that can be used in gene research. Iodine 125 decays via electron capture emitting a 35 keV gamma-ray with the prompt emission of several 27-32 KeV X-rays. A coincidence condition can be set to detect the I-125 decays thus reducing background radiation contribution to the image. The system utilizes the Hamamatsu 5 inch diameter 3292 position sensitive photomultiplier tube (PSPMT) coupled to the CsI(Na) matrix and a custom built high resolution copper-beryllium collimator. A conventional photomultiplier coupled to a NaI (Tl) crystal scintillator is used to detect the coincident radiation resulting from the decay of I-125. C1 Thomas Jefferson Natl Accelerator Facil, Detector Grp, Newport News, VA USA. RP Weisenberger, AG (reprint author), Thomas Jefferson Natl Accelerator Facil, Detector Grp, Newport News, VA USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 1140 EP 1144 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900247 ER PT B AU Beuville, E Cahn, R Cederstrom, B Danielsson, M Hall, A Hasegawa, B Luo, L Lundqvist, M Nygren, D Oltman, E Vestlund, J Walton, J AF Beuville, E Cahn, R Cederstrom, B Danielsson, M Hall, A Hasegawa, B Luo, L Lundqvist, M Nygren, D Oltman, E Vestlund, J Walton, J BE Nalcioglu, O TI High resolution X-ray imaging using a silicon strip detector SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB We are presenting the first images and an initial evaluation of a scanned-slot X-ray imaging system based on edge-on silicon strip detectors and high-speed low-noise parallel processing ASICs. We have demonstrated noiseless single photon counting above a minimal threshold of 7.2 keV. Edge scans show negligible cross talk between different channels in the ASIC. The Modulation Transfer Function (MTF) has been measured and found to agree with the ideal MTF for 100 mu m pixel size. The first images are obtained at very low exposures and show the high performance of the system. We also present a way of enhancing the X-ray flux to a slot by using a refractive X-ray lens. We believe this focusing device will significantly enhance the potential for scanned-slot X-ray imaging. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Beuville, E (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 1269 EP 1273 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900274 ER PT B AU Klein, GJ Reutter, BW Ho, MH Reed, JH Huesman, RH AF Klein, GJ Reutter, BW Ho, MH Reed, JH Huesman, RH BE Nalcioglu, O TI Real-time system for respiratory-cardiac gating in positron tomography SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB A Macintosh-based signal processing system has been developed to support simultaneous respiratory and cardiac gating on the ECAT EXACT HR PET scanner. Using the Lab-View real-time software environment, the system reads analog inputs from a pneumatic respiratory bellows and an ECG monitor to compute an appropriate histogram memory location for the PET data. Respiratory state is determined by the bellows signal amplitude; cardiac state is based on the time since the last R-wave. These two states are used in a 2D lookup table to determine a combined respiratory-cardiac state. A 4-bit address encoding the selected histogram is directed from the system to the ECAT scanner, which dynamically switches the destination of tomograph events as respiratory-cardiac state changes. To test the switching efficiency of the combined Macintosh/ECAT system, a rotating emission phantom was built. Acquisitions with 25 msec gates while the phantom was rotating at 240 rpm demonstrate the system could effectively stop motion at this rate, with approximately 5 msec switching time between gates. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Klein, GJ (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Ctr Funct Imaging, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 1284 EP 1287 PG 4 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900277 ER PT B AU Reutter, BW Gullberg, GT Huesman, RH AF Reutter, BW Gullberg, GT Huesman, RH BE Nalcioglu, O TI Kinetic parameter estimation from attenuated SPECT projection measurements SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB Kinetic parameters are commonly estimated from dynamically acquired nuclear medicine data by first reconstructing a temporal sequence of images and subsequently fitting the parameters to time-activity curves generated from regions of interest overlaid upon the image sequence. Biased estimates can result from images reconstructed using inconsistent projections of a time-varying distribution of radiopharmaceutical acquired by a rotating SPECT system. To overcome this problem we investigated the estimation of kinetic parameters directly from projection data by modeling the data acquisition process. To accomplish this it was necessary to parametrize the spatial and temporal distribution of the radiopharmaceutical within the SPECT field of view. In a simulated transverse slice, kinetic parameters were estimated for simple one compartment models for three myocardial regions of interest, as well as for the liver. Myocardial uptake and washout parameters estimated by conventional analysis of noiseless simulated data had biases ranging between 1-63%. Parameters estimated directly from the noiseless projection data were unbiased as expected, since the model used for fitting was faithful to the simulation. Parameter uncertainties for 500,000 detected events ranged between 1-25% for the myocardial uptake parameters and 1-18% for the myocardial washout parameters. C1 Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. RP Reutter, BW (reprint author), Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Ctr Funct Imaging, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 1340 EP 1344 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900289 ER PT B AU Gleason, SS Sari-Sarraf, H Hudson, KT Hubner, KF AF Gleason, SS Sari-Sarraf, H Hudson, KT Hubner, KF BE Nalcioglu, O TI Higher accuracy and throughput in computer-aided screening of mammographic microcalcifications SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB This paper outlines a new methodology for computer-aided screening (CAS) of microcalcifications. The proposed approach takes advantage of the research already performed in the held of CAS and facilitates its translation to practical screening systems by exploring two concepts that address the key issues of (1) higher accuracy and (2) higher throughput. The first concept involves the utilization of a front-end fractal encoding scheme that analyzes digitized mammograms and generates focus-of-attention regions (FARs). The second concept is that of distributed segmentation, that is, subjecting FARs to multiple microcalcification segmentation techniques. To validate the impact of FAR generation on the ensuing processes in GAS, specifically that of segmentation, an existing segmentation technique was selected and applied to 100 digitized mammograms (45 with and 55 without microcalcifications). Utilizing the selected segmentation technique in conjunction with the proposed fractal encoding scheme reduced the number of false detections from 310 to 53 (83% reduction) in images with microcalcifications and from 931 to 197 (79% reduction) in images without microcalcifications. This was accomplished while maintaining a coverage rate of 88%. In addition, the input data were reduced by up to 99%. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Gleason, SS (reprint author), Oak Ridge Natl Lab, POB 2008,Bldg 3546,MS 6011, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 1464 EP 1468 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900316 ER PT B AU Cunningham, GS Hanson, KM Battle, XL AF Cunningham, GS Hanson, KM Battle, XL BE Nalcioglu, O TI Three dimensional reconstructions from low-count SPECT data using deformable models SO 1997 IEEE NUCLEAR SCIENCE SYMPOSIUM - CONFERENCE RECORD, VOLS 1 & 2 LA English DT Proceedings Paper CT 1997 IEEE Nuclear Science Symposium and Medical Imaging Conference CY NOV 09-15, 1997 CL ALBUQUERQUE, NM SP IEEE AB We demonstrate the reconstruction of a 3D, time-varying bolus of radiotracer from first-pass data obtained at the dynamic SPECT imager, FASTSPECT, built by the University of Arizona. The object imaged is a CardioWest Total Artificial Heart. The bolus is entirely contained in one ventricle and its associated inlet and outlet tracts. The model for the radiotracer distribution is a time-varying closed surface parameterized by 162 vertices that are connected to make 960 triangles, with uniform intensity of radiotracer inside. The total curvature of the surface is minimized through the use of a weighted prior in the Bayesian framework. MAP estimates for the vertices, interior intensity and background scatter are produced for diastolic and systolic frames, the only two frames analyzed. The strength of the prior is determined by finding the corner of the L-curve. The results indicate that qualitatively pleasing results are possible even with as few as 1780 counts per time frame (total after summing over all 24 detectors). Quantitative results will require correcting certain undesirable features of the reconstruction due to inappropriate assumptions in the model, e.g. inhomogeneities in the radiotracer distribution and smoothness of the surface at the tract/ventricle join. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Cunningham, GS (reprint author), Univ Calif Los Alamos Natl Lab, MS P940, Los Alamos, NM 87545 USA. RI Cunningham, Gregory/F-1017-2011 OI Cunningham, Gregory/0000-0001-8819-4345 NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4259-3 PY 1998 BP 1469 EP 1473 PG 5 WC Instruments & Instrumentation; Nuclear Science & Technology; Physics, Nuclear; Radiology, Nuclear Medicine & Medical Imaging SC Instruments & Instrumentation; Nuclear Science & Technology; Physics; Radiology, Nuclear Medicine & Medical Imaging GA BL13T UT WOS:000074401900317 ER PT B AU Koontz, R Blokhina, G Gold, S Krasnykh, A AF Koontz, R Blokhina, G Gold, S Krasnykh, A GP IEEE, DIELECT & INSULAT SOC IEEE, DIELECT & INSULAT SOC TI High dielectric constant materials for pulsed energy storage capacitors SO 1998 ANNUAL REPORT CONFERENCE ON ELECTRICAL INSULATION AND DIELECTRIC PHENOMENA, VOLS 1 AND 2 LA English DT Proceedings Paper CT 67th Annual Conference on Electrical Insulation and Dielectric Phenomena CY OCT 25-28, 1998 CL ATLANTA, GA SP IEEE, Dielect & Insulat Soc AB A high dielectric constant coupled with a high dielectric strength is essential in producing high energy density, low inductance capacitors used in pulsed energy systems. The NLC (Next Linear Collider) which is envisioned as the next step in high energy physics research tools will employ several thousand pulsed klystron RF sources. The modulators for these klystrons require efficient, reliable energy storage capacitors. Collaboration with Russian scientists has made available to us information and capacitor samples based on the Tungsten-Bronze family which exhibit dielectric constants of over 1,000, and working voltage gradients in excess of 60 kV/cm. We are currently testing 10 nanofarad, 40 kV capacitor samples in pulsed modulator service manufactured at the GIRIKOND Institute in St. Petersburg, Russia. Dr. Galina Blokhina is the designer of these capacitors. The material is a solid solution of complex compounds of niobate dielectric. The Tungsten-Bronze-Type Crystals are bound in amorphous glass. The paper summarizes the theoretical studies of this material with a Russian and English bibliography, describes Dr. Blokhina's manufacturing processes, and presents the results of pulsed energy storage testing carried out at SLAG for the NLC R&D effort. It is the intent of this paper to spark interest in transferring this technology to the world community so that R&D in this area will expand and provide this technology to many users including the NLC project. C1 Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Koontz, R (reprint author), Stanford Linear Accelerator Ctr, POB 4349, Stanford, CA 94309 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5035-9 PY 1998 BP 23 EP 26 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BM01M UT WOS:000077417300004 ER PT S AU Foster, I Kesselman, C AF Foster, I Kesselman, C BE Vandoni, CE TI Computational grids SO 1998 CERN SCHOOL OF COMPUTING, PROCEEDINGS SE C E R N REPORTS LA English DT Proceedings Paper CT 21st CERN School of Computing CY SEP 06-19, 1998 CL FUNCHAL, PORTUGAL SP European Org Nucl Res ID GROUP COMMUNICATION-SYSTEM; DESIGN AB This article introduces the key concepts underlying computational grids. The article is structured in terms of six questions: Why do we need computational grids? What types of applications will they be used for? Who will use grids? How will they program them? What is involved in building a grid? What problems remain to be solved before grids become commonplace? C1 Argonne Natl Lab, Div Math & Comp Sci, Argonne, IL 60439 USA. RP Foster, I (reprint author), Argonne Natl Lab, Div Math & Comp Sci, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 76 TC 0 Z9 0 U1 0 U2 0 PU C E R N PI GENEVA PA MEYRIN, CH-1211 GENEVA, SWITZERLAND SN 0007-8328 BN 92-9083-136-7 J9 CERN REPORT PY 1998 VL 98 IS 08 BP 87 EP 113 PG 27 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering SC Computer Science GA BM56Z UT WOS:000079121400006 ER PT B AU Kupferman, SL AF Kupferman, SL BE Nelson, TL TI Deployment of a compact, transportable, fully automated Josephson voltage standard SO 1998 CONFERENCE ON PRECISION ELECTROMAGNETIC MEASUREMENTS DIGEST LA English DT Proceedings Paper CT 1998 Conference on Precision Electromagnetic Measurements (CPEM 98) CY JUL 06-10, 1998 CL WASHINGTON, D.C. SP Natl Inst Stand & Technol, Bur Int Poids & Mesures, IEEE, Instrumentat & Measurement Soc, Natl Res Council Canada, Union Radio Sci Int, Amer Assoc Lab Accreditat, Andeen Hagerling Inc, APS, Instrument & Measurement Sci Top Grp, APS, Precis Measurement & Fundamental Constants, Baltimore Gas & Elect, Cal Lab Magazine, Clarke Hess Commun Res Corp, Creat Mkt Assoc, Fluke Corp, Guildline Instruments, Hewlett Packard Co, Instrument Support Solut Div, IEEE, Instrument & Measurement Soc, Washington Chapter, IEEE, Natl Capital Area Council, Natl Conf Stand Lab, Org Amer States, Wavetek Corp AB The development of a compact portable 10 V Josephson voltage standard has been described previously. Here we discuss modifications, accuracy intercomparisons, field testing and operator training carried out prior to its deployment as a traveling primary standard for nine NASA standards laboratories. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kupferman, SL (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5018-9 PY 1998 BP 307 EP 308 DI 10.1109/CPEM.1998.699923 PG 2 WC Engineering, Electrical & Electronic; Instruments & Instrumentation; Optics; Spectroscopy SC Engineering; Instruments & Instrumentation; Optics; Spectroscopy GA BL51B UT WOS:000075725900160 ER PT B AU Pollock, GM AF Pollock, GM GP IEEE TI Dynamic visualization techniques for high consequence software SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 4 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB This report documents a prototype tool developed to investigate the use of visualization and virtual reality technologies for improving software surety confidence. The tool is utilized within the execution phase of the software life cycle. It provides a capability to monitor an executing program against prespecified requirements constraints provided in a program written in the requirements specification language SAGE. The resulting Software Attribute Visual Analysis Tool (SAVAnT) also provides a technique to assess the completeness of a software specification. The prototype tool is described along with the requirements constraint language after a brief literature review is presented. Examples of how the tool can be used are also presented. In conclusion, the most significant advantage of this tool is to provide a first step in evaluating specification completeness, and to provide a more productive method for program comprehension and debugging. The expected payoff is increased software surety confidence, increased program comprehension, and reduced development and debugging time. C1 Sandia Natl Labs, Dept Comp Sci, Albuquerque, NM 87185 USA. RP Pollock, GM (reprint author), Sandia Natl Labs, Dept Comp Sci, POB 5800,MS 1109, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 277 EP 296 PG 20 WC Engineering, Aerospace; Computer Science, Information Systems; Computer Science, Software Engineering; Telecommunications SC Engineering; Computer Science; Telecommunications GA BL20H UT WOS:000074665100024 ER PT B AU Rienstra, J Ballard, M AF Rienstra, J Ballard, M GP IEEE TI Multispectral focal plane assembly for satellite remote sensing SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 5 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB Sandia National Laboratories and several subsystem contractors are developing technologies applicable to multispectral remote sensing from space. A proof of concept multispectral sensor system is under development. The objective of building this sensor is to demonstrate and evaluate multispectral imaging technologies for various applications. The three major subsystems making up the sensor are the focal plane assembly (FPA), the cryocooler, and the telescope. This paper covers the focal plane assembly, which is the basis of the sensor system. The focal plane assembly includes sensor chip assemblies, optical filters, and a vacuum enclosure with cold shielding. Linear detector arrays provide spatial resolution in the cross-track direction for a pushbroom imager configuration. The optical filters define 15 spectral bands in a range from 0.45 mu m to 10.7 mu m. All the detector arrays are mounted on a single focal plane and are designed to operate at 75 K. No beam splitters are used. The four spectral bands covering the visible to near infrared have roughly 2400 pixels each, and the remaining 11 spectral bands have roughly 600 pixels each. The average total rate of multispectral data from the FPA is approximately 15.4 megapixels per second. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Rienstra, J (reprint author), Sandia Natl Labs, POB 5800,M-S 0972, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 233 EP 241 PG 9 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL20J UT WOS:000074665200024 ER PT B AU Choquette, KD Hou, HQ Geib, KM Hammons, BE AF Choquette, KD Hou, HQ Geib, KM Hammons, BE GP IEEE TI Selectively oxidized vertical-cavity laser performance and technology SO 1998 IEEE AEROSPACE CONFERENCE PROCEEDINGS, VOL 5 LA English DT Proceedings Paper CT IEEE Aerospace Conference CY MAR 21-28, 1998 CL ASPEN, CO SP IEEE, Aerosp & Electr Syst Soc AB We discuss revolutionary performance advances in selectively oxidized vertical-cavity surface emitting lasers (VCSELs), which have enabled low operating power laser diodes appropriate for aerospace applications. Incorporating buried oxide layers converted from AlGaAs layers within the laser cavity produces enhanced optical and electrical confinement enabling superior laser performance, such as high efficiency and modulation bandwidth. VCSELs are also shown to be viable over varied environmental conditions such as ambient temperature and ionized radiation. The development of novel VCSEL technologies for advanced system applications is also described. Two-dimensional individually addressable VCSEL arrays exhibit uniform threshold and operating characteristics. Bottom emitting 850 nm VCSEL arrays fabricated using wafer fusion are also reported. C1 Sandia Natl Labs, Ctr Compound Semicond Sci & Technol, Albuquerque, NM 87185 USA. RP Choquette, KD (reprint author), Sandia Natl Labs, Ctr Compound Semicond Sci & Technol, POB 5800 MS0603, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4311-5 PY 1998 BP 283 EP 288 PG 6 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BL20J UT WOS:000074665200028 ER PT S AU Cong, G Parvin, B AF Cong, G Parvin, B GP IEEE COMP SOC IEEE COMP SOC TI Shape from Equal Thickness Contours SO 1998 IEEE COMPUTER SOCIETY CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION, PROCEEDINGS SE PROCEEDINGS - IEEE COMPUTER SOCIETY CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION LA English DT Proceedings Paper CT 1998 IEEE Computer-Society Conference on Computer Vision and Pattern Recognition CY JUN 23-25, 1998 CL SANTA BARBARA, CA SP IEEE Comp Soc, Tech Comm Pattern Anal & Machine Intelligence AB A unique imaging modality based on Equal Thickness Contours (ETC) has introduced a new opportunity for 3D shape reconstruction from multiple views. We present a computational framework for representing each view of an object in terms of its object thickness, and then integrating these representations into a SD surface by algebraic reconstruction. The object thickness is inferred by grouping curve segments that correspond to points of second derivative maxima. At each step of the process, we use some form of regularization to ensure closeness to the original features, as well as neighborhood continuity. We apply our approach to images of a sub-micron crystal structure obtained through a holographic process. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Informat & Comp Sci Div, Berkeley, CA 94720 USA. RP Cong, G (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Informat & Comp Sci Div, Berkeley, CA 94720 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1063-6919 BN 0-8186-8497-6 J9 PROC CVPR IEEE PY 1998 BP 502 EP 507 DI 10.1109/CVPR.1998.698652 PG 6 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL27E UT WOS:000074947400073 ER PT S AU Sari-Sarraf, H Goddard, JS AF Sari-Sarraf, H Goddard, JS GP IEEE COMP SOC IEEE COMP SOC TI Robust defect segmentation in woven fabrics SO 1998 IEEE COMPUTER SOCIETY CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION, PROCEEDINGS SE PROCEEDINGS - IEEE COMPUTER SOCIETY CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION LA English DT Proceedings Paper CT 1998 IEEE Computer-Society Conference on Computer Vision and Pattern Recognition CY JUN 23-25, 1998 CL SANTA BARBARA, CA SP IEEE Comp Soc, Tech Comm Pattern Anal & Machine Intelligence AB This paper describes a robust segmentation algorithm far the detection and localization of woven fabric defects. The essence of the presented segmentation algorithm is the localization of those events (i.e., defects) in the input images that disrupt the global homogeneity of the background texture. To this end, preprocessing modules, based on the wavelet transform and edge fusion, al-e employed with the objective of attenuating the background texture and accentuating the defects. Then, texture features are utilized to measure the global homogeneity of the output images, if these images are deemed to be globally nonhomogenous (i.e., defects are present), a local roughness measure is used to localize the defects. The utility of this algorithm can be extended beyond the specific application in our work, that is, defect segmentation in woven fabrics. indeed, in a general sense, this algorithm can be used to detect and to localize anomalies that reside in images characterized by ordered texture. The efficacy of this algorithm has been tested thoroughly under realistic conditions and as a part of an on-line fabric inspection system. Using over 3700 images of fabrics, containing 26 different types of defects, the overall detection rate of our approach was 89% with a localization accuracy of less than 0.2 incites and a false alarm rate of 2.5%. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Sari-Sarraf, H (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 14 Z9 14 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1063-6919 BN 0-8186-8497-6 J9 PROC CVPR IEEE PY 1998 BP 938 EP 944 DI 10.1109/CVPR.1998.698717 PG 7 WC Computer Science, Artificial Intelligence; Computer Science, Interdisciplinary Applications SC Computer Science GA BL27E UT WOS:000074947400137 ER PT B AU Andrews, JJ Mcclung, LB White, TJ AF Andrews, JJ Mcclung, LB White, TJ GP IEEE TI Ensuring that electrical equipment is safe for its intended use SO 1998 IEEE INDUSTRIAL & COMMERCIAL POWER SYSTEMS TECHNICAL CONFERENCE - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Industrial and Commercial Power Systems Technical Conference CY MAY 03-08, 1998 CL EDMONTON, CANADA SP IEEE, Ind Applicat Soc, Ind Power Syst Dept, IEEE, PES & IAS No Canada Chapter AB The Occupational Safety and Administration (OSHA) regulations, the National Electrical Code (NEC), and several other nationally recognized Standards and Recommended Practices, indicate that electrical equipment must be inspected tested and evaluated to ensure that it is essentially free of hazards. Manufacturer-supplied standard lines containing "approved" components, and manufacturer-supplied assemblies that are "listed" by a "Nationally Recognized Testing Laboratory (NRTL)", are acceptable to OSHA. When no NRTL accepts, certifies, lists, or labels a particular piece of equipment, or determines if to be safe, special actions, involving the authority having jurisdiction (AHJ), are required to assure that the equipment complies with regulations. Such equipment would include custom-made one-of-a-kind equipment, equipment made "in-house" for research or other special purposes, and equipment manufactured outside of the United States. This Paper gives guidance towards ensuring that electrical equipment meets the safety intention of present-day regulations, codes, and standards. C1 Westinghouse Savannah River Co, Aiken, SC 29808 USA. RP Andrews, JJ (reprint author), Westinghouse Savannah River Co, Savannah River Site, Aiken, SC 29808 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4509-6 PY 1998 BP 119 EP 126 DI 10.1109/ICPS.1998.692554 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BL49Y UT WOS:000075702700017 ER PT B AU Andrews, JJ Marshall, JA AF Andrews, JJ Marshall, JA GP IEEE TI A detailed investigation of an electrical shock and burn injury SO 1998 IEEE INDUSTRIAL & COMMERCIAL POWER SYSTEMS TECHNICAL CONFERENCE - CONFERENCE RECORD LA English DT Proceedings Paper CT IEEE Industrial and Commercial Power Systems Technical Conference CY MAY 03-08, 1998 CL EDMONTON, CANADA SP IEEE, Ind Applicat Soc, Ind Power Syst Dept, IEEE, PES & IAS No Canada Chapter AB Even with appropriate lockouts in place for the job being done, a fully trained and qualified electrician received a severe electrical shock, third degree burns, and lacerations when he made contact with an energized 480 volt cable lug attached to a circuit breaker terminal. Although he had, to be hospitalized for two days, the electrician survived and was able to contribute to the incident investigation. The investigation showed that a variety of deficiencies, rebated to electrical safety, combined to allow the injury to occur. This paper describes the results of the detailed investigation of the incident, and identifies the variety of accident contributors, which, had they been recognized and addressed, might have prevented the injury. These potential contributors are items that should be addressed in everyone's Electrical Safety Program. C1 Westinghouse Savannah River Co, Aiken, SC 29808 USA. RP Andrews, JJ (reprint author), Westinghouse Savannah River Co, Savannah River Site, Aiken, SC 29808 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4509-6 PY 1998 BP 143 EP 154 DI 10.1109/ICPS.1998.692557 PG 4 WC Energy & Fuels; Engineering, Electrical & Electronic SC Energy & Fuels; Engineering GA BL49Y UT WOS:000075702700020 ER PT B AU Touzet, C Santos, JM AF Touzet, C Santos, JM GP IEEE TI Reinforcement function design and bias for efficient learning in mobile robots SO 1998 IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS AT THE IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE - PROCEEDINGS, VOL 1-2 LA English DT Proceedings Paper CT IEEE International Conference on Fuzzy Systems at the World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP IEEE, Neural Networks Council, Int Neural Network Soc, IEEE, Alaska Sect AB The main paradigm in sub-symbolic learning robot domain is the reinforcement learning method Various techniques have been developed to deal with the memorization/generalization problem, demonstrating the superior ability of artificial neural network implementations. In this paper, we address the issue of designing the reinforcement so as to optimize the exploration part of the learning. We also present and summarize works relative to the use of bias intended to achieve the effective synthesis of the desired behavior. Demonstrative experiments involving a self-organizing map implementation of the O-learning and real mobile robots (Nomad 200 and Khepera) in a task of obstacle avoidance behavior synthesis are described. C1 Oak Ridge Natl Lab, CESAR, Oak Ridge, TN 37831 USA. RP Touzet, C (reprint author), Oak Ridge Natl Lab, CESAR, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4863-X PY 1998 BP 153 EP 158 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BL20P UT WOS:000074668800027 ER PT B AU Cooper, JA Ross, TJ AF Cooper, JA Ross, TJ GP IEEE TI The application of new mathematical structures to safety analysis SO 1998 IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS AT THE IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE - PROCEEDINGS, VOL 1-2 LA English DT Proceedings Paper CT IEEE International Conference on Fuzzy Systems at the World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP IEEE, Neural Networks Council, Int Neural Network Soc, IEEE, Alaska Sect AB Probabilistic safety analyses (PSAs) often depend on significant subjectivity. The recent successes of fuzzy logic and fuzzy and hybrid mathematics in portraying subjectivity is a reminder that a selection made from the most applicable mathematical tools is more important than forced adaptation of conventional tools. In this paper, we consider new approaches that enhance conventional and fuzzy PSA by improved handling of subjectivity. The most significant of the mathematical structures we have investigated (from a standpoint of safety analysis applications) will be described, and the general types of applications will be outlined. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cooper, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4863-X PY 1998 BP 692 EP 697 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BL20P UT WOS:000074668800123 ER PT B AU Jacobsen, HA AF Jacobsen, HA GP IEEE TI A generic architecture for hybrid intelligent systems SO 1998 IEEE INTERNATIONAL CONFERENCE ON FUZZY SYSTEMS AT THE IEEE WORLD CONGRESS ON COMPUTATIONAL INTELLIGENCE - PROCEEDINGS, VOL 1-2 LA English DT Proceedings Paper CT IEEE International Conference on Fuzzy Systems at the World Congress on Computational Intelligence (WCCI 98) CY MAY 04-09, 1998 CL ANCHORAGE, AK SP IEEE, Neural Networks Council, Int Neural Network Soc, IEEE, Alaska Sect DE intelligent systems; neuro-fuzzy approaches; agent paradigm; intelligent prefetching over wireless media AB The integration of different learning and adaptation techniques in one architecture, to overcome individual limitations and achieve synergetic effects through hybridization or fusion of these techniques, has in recent years contributed to a large number of new intelligent system designs. Most of these approaches, however, follow an ad hoc design methodology, further justified by success in certain application domains. Due to the lack of a common framework it remains often difficult to compare the various systems conceptually and evaluate their performance comparatively. In this paper we first aim at classifying state-of-the-art intelligent systems, which have evolved over the past decade in the soft computing community. We identify four categories, based on the systems' overall architecture: (1) single component systems, (2) fusion-based systems, (3) hierarchical systems, and (4) hybrid systems. We then introduce a unifying paradigm, derived from concepts well known in the AI and agent community, as conceptual framework to better understand, modularize, compare and evaluate the individual approaches. We think it is crucial for the design of intelligent systems to focus on the integration and interaction of different learning techniques in one model rather then merging them to create ever new techniques. Two original instantiations of this framework are presented and discussed. Their performance is evaluated for prefetching of bulk data over wireless media. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Jacobsen, HA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4863-X PY 1998 BP 709 EP 714 PG 6 WC Computer Science, Artificial Intelligence SC Computer Science GA BL20P UT WOS:000074668800126 ER PT S AU Luck, JP Little, CQ Roberts, RS AF Luck, JP Little, CQ Roberts, RS GP IEEE TI A human supervisory approach to modeling industrial scenes using geometric primitives SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB A three-dimensional world model is crucial for many robotic tasks. Modeling techniques tend to be either fully manual or autonomous. Manual methods are extremely time consuming but also highly accurate and flexible. Autonomous techniques are fast but inflexible and, with real-world data, often inaccurate. The method presented in this paper combines the two, yielding a highly efficient, flexible, and accurate mapping tool. The segmentation and modeling algorithms that compose the method are specifically designed for industrial environments, and are described in detail. A mapping system based on these algorithms has been designed. It enables a human supervisor to quickly construct a fully defined world model from unfiltered and unsegmented real-world range imagery. Examples of how industrial scenes are modeled with the mapping system are provided. C1 Colorado Sch Mines, Golden, CO 80401 USA. RP Luck, JP (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 875 EP 880 PG 6 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900139 ER PT S AU Feddema, JT Robinett, RD Driessen, BJ AF Feddema, JT Robinett, RD Driessen, BJ GP IEEE TI Designing stable finite state machine behaviors using phase plane analysis and variable structure control SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB This paper discusses how phase plane analysis can be used to describe the overall behavior of single and multiple autonomous robotic vehicles with finite state machine rules. The importance of this result is that we can begin to design provably asymptotically stable group behaviors from a set of simple control laws and appropriate switching points with decentralized variable structure control. The ability to prove asymptotically stable group behavior is especially important for applications such as locating military targets or land mines. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Feddema, JT (reprint author), Sandia Natl Labs, POB 5800,MS 1003, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 1134 EP 1141 PG 2 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900180 ER PT S AU Feddema, JT Simon, RW AF Feddema, JT Simon, RW GP IEEE TI CAD-driven microassembly and visual Servoing SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB This paper describes current research and development on a robotic visual servoing system for assembly of LIGA (Lithography Galvonoforming Abforming) parts. The workcell consists of an AMTI robot, precision stage, long working distance microscope, and LIGA fabricated. tweezers for picking up the parts. Fourier optics methods are used to generate synthetic microscope images from CAD drawings. These synthetic images are used off-line to test image processing routines under varying magnifications and depths of field. They also provide reference image features which are used to visually servo the part to the desired position. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Feddema, JT (reprint author), Sandia Natl Labs, POB 5800,MS 1003, Albuquerque, NM 87185 USA. NR 0 TC 17 Z9 20 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 1212 EP 1219 PG 2 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900192 ER PT S AU Kwok, KS Loucks, CS Driessen, BJ AF Kwok, KS Loucks, CS Driessen, BJ GP IEEE TI Rapid 3-D digitizing and tool path generation for complex shapes SO 1998 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION, VOLS 1-4 SE IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION LA English DT Proceedings Paper CT IEEE International Conference on Robotics and Automation CY MAY 16-20, 1998 CL KATHOLIEKE UNIV LEUVEN, LEUVEN, BELGIUM SP IEEE, Robot & Automat Soc, Consiglio Nazl Ric, Fund Sci Res, Flanders, Belgium, Fraunhofer Inst Produktionstechnik & Automatisier, Commiss European Communities, INRIA, BULL, CNES, DAIMLER, KUKA, MATRA, SIEMENS, TECNOSPAZIO, THOMSON-CSF HO KATHOLIEKE UNIV LEUVEN AB A system for automatic tool path generation was developed at Sandia National Laboratories for finish machining operations. The system consists of a commercially available 5-axis milling machine controlled by Sandia developed software. This system was used to remove overspray on cast turbine blades. A laser-based, structured-light sensor, mounted on a tool holder, is used to collect 3D data points around the surface of the turbine blade. Using the digitized model of the blade, a tool path is generated which will drive a 0.375" CBN grinding pin around the tip of the blade. A fuzzified digital filter was developed to properly eliminate false sensor readings caused by burrs, holes and overspray. The digital filter was found to successfully generate the correct tool path for a blade with intentionally scanned holes and defects. The fuzzified filter improved the computation, efficiency by a factor of 25. For application to general parts, an adaptive scanning algorithm was developed and presented with simulation and experimental results. A right pyramid and an ellipsoid were scanned successfully with the adaptive algorithm in simulation studies. In actual experiments, a nose cone and a turbine blade were successfully scanned. A complex shaped turbine blade was successfully scanned and finish machined using these algorithms. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Kwok, KS (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1050-4729 BN 0-7803-4300-X J9 IEEE INT CONF ROBOT PY 1998 BP 2789 EP 2794 PG 4 WC Automation & Control Systems SC Automation & Control Systems GA BL12F UT WOS:000074368900443 ER PT S AU Garcia, HE Vilim, RB AF Garcia, HE Vilim, RB GP IEEE IEEE IEEE IEEE TI Combining physical modeling, neural processing, and likelihood testing for online process monitoring SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB Two basic approaches can be taken to model physical systems. One approach derives a model structure from the known physical laws. However, obtaining a model with the required fidelity can be difficult if the system is not well understood. A second approach is to employ a black-box structure to learn the implicit input-output relationships from measurements in which no particular attention is paid to modeling the underlying processes. Clearly one should exploit whatever physical insight one has into the properties of the system. This paper describes a method that draws on the respective strengths of each of these two approaches. The technique combines known first principles knowledge derived from physical modeling with measured input-output mappings derived from neural processing to produce a computer model of a dynamical process. The technique is used to diagnose operational changes of mechanical equipment by statistically comparing, using a likelihood test, the predicted model output for the given measured input with the actual process output. Experiments with a peristaltic pump were conducted and results are presented here. C1 Argonne Natl Lab, Technol Dev Div, Idaho Falls, ID 83403 USA. RP Garcia, HE (reprint author), Argonne Natl Lab, Technol Dev Div, POB 2528, Idaho Falls, ID 83403 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 806 EP 810 PG 5 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700139 ER PT S AU Dress, W AF Dress, W GP IEEE IEEE IEEE IEEE TI A Bayesian approach to extracting meaning from system behavior SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB The modeling relation and its reformulation to include the semiotic hierarchy is essential for the understanding, control, and successful re-creation of natural systems. This presentation will argue for a careful application of Rosen's modeling relationship to the problems of intelligence and autonomy in natural and artificial systems. To this end, I discuss the essential need for a correct theory of induction, learning, and probability; and suggest that modern Bayesian probability theory, developed by Cox, Jaynes, and others, can adequately meet such demands, especially on the operational level of extracting meaning from observations. The methods of Bayesian and Maximum Entropy parameter estimation have been applied to measurements of system observables to directly infer the underlying differential equations generating system behavior. This approach bypasses the usual method of parameter estimation based on assuming a functional form for the observable and then estimating the parameters that would lead to the particular observed behavior. The computational savings is great since only location parameters enter into the maximum-entropy calculations; this innovation finesses the need for nonlinear parameters altogether. Such an approach more directly extracts the semantics inherent in a given system by going to the root of system meaning as expressed by abstract form or shape, rather than in syntactic particulars, such as signal amplitude and phase. Examples will be shown how the form of a system can be followed while ignoring unnecessary details. In this sense, we are observing the meaning of the "words" rather than being concerned with their particular expression or "language." For the present discussion, empirical models are embodied by the differential equations underlying, producing, or describing the behavior of a process as measured or tracked by a particular variable set-the observables. The a priori models are probability structures that capture syntactical relationships within the formal system that mirrors the natural system under observation. Inductive learning is then a prescription for incorporating the current, and possibly changing, empirical model into an iterative syntactical relationship in the form of a statement about parameters, producing an updated a priori model subject to future modification in the light of changing parameter sets. The probabilistic nature of the model descriptions replaces the rigid structures normally used with a flexible descriptions. These structures then evolve both with new knowledge about the system under study as well as with temporal evolution as the system changes its form or structure in response to environmental interactions or internal dynamics. The implications for anticipatory control and understanding of natural and artificial systems are evident and unfold into possibilities for the creation of complex artificial systems. C1 Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37831 USA. RP Dress, W (reprint author), Oak Ridge Natl Lab, Div Instrumentat & Controls, POB 2008 MS 6011, Oak Ridge, TN 37831 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 2243 EP 2248 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700393 ER PT S AU Kercel, SW AF Kercel, SW GP IEEE IEEE IEEE IEEE TI Peering through a dirty window: A Bayesian approach to making mine detection decisions from noisy data SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB For several reasons, Bayesian parameter estimation is superior to other methods for extracting features of a weak signal from noise. Since it exploits prior knowledge, the analysis begins from a more advantageous starting point than other methods. Also, since "nuisance parameters" can be dropped out of the Bayesian analysis, the description of the model need not be as complete as is necessary for such methods as matched filtering. In the limit for perfectly random noise and a perfect description of the model, the signal-to-noise ratio improves as the square root of the number of samples in the data. Even with the imperfections of real-world data, Bayesian approaches this ideal limit of performance more closely than other methods. A major unsolved problem in landmine detection is the fusion of data from multiple sensor types. Bayesian data fusion is only beginning to be explored as a solution to the problem. In single sensor processes Bayesian analysis can sense multiple parameters from the data stream of the one sensor. It does so by computing a joint probability density function of a set of parameter values from the sensor output. However, there is no inherent requirement that the information must come from a single sensor. If multiple sensors are applied to a single process, where several different parameters are implicit in each sensor output data stream, the joint probability density function of all the parameters of interest can be computed in exactly the same manner as the single sensor case. Thus, it is just as practical to base decisions on multiple sensor outputs as it is for single sensors. This should provide a practical way to combine the outputs of dissimilar sensors, such as ground penetrating radar and electromagnetic induction devices, producing a better detection decision than could be provided by either sensor alone. C1 Oak Ridge Natl Lab, Div Instrumentat & Controls, Oak Ridge, TN 37831 USA. RP Kercel, SW (reprint author), Oak Ridge Natl Lab, Div Instrumentat & Controls, POB 2008 MS 6011, Oak Ridge, TN 37831 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 2249 EP 2254 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700394 ER PT S AU Cooper, JA AF Cooper, JA GP IEEE IEEE IEEE IEEE TI Constrained mathematics analysis of uncertain variables SO 1998 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5 SE IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Conference on Systems, Man, and Cybernetics - Intelligent Systems for Humans in a Cyberworld (SMC 98) CY OCT 11-14, 1998 CL SAN DIEGO, CA SP IEEE, Syst Man & Cybernet Soc AB Analyses (e.g., safety analyses and reliability analyses) that are based on variable or uncertain inputs need to reflect the ranges of potential output variability or uncertainty. A challenging problem in mathematically processing the operands is that constraints inherent in the problem definition can require computations that are difficult to implement. Examples of possible constraints are that the sum of the probabilities of partitioned possible outcomes must be one, and repeated appearances of the same variable must all have the identical value. The latter, called the "repeated variable problem" will be addressed in this paper in order to show how range-based probabilistic evaluation of Boolean logic expressions, such as those describing the outcomes of fault trees and event trees, can be facilitated. The results are applicable to fuzzy mathematics, interval analysis, Monte Carlo analysis and other range-based techniques. The problem is important, because unconstrained computations result in wider ranges of outputs than those properly obtained with constrained mathematics. We illustrate techniques that can be used to transform complex constrained problems into trivial problems in most tree logic expressions, and into tractable problems in most other cases. The approach is based on the Boolean logic characteristics of "unateness" and "minimal compactness," and differential calculus characteristics related to regions of monotonicity. Example problems are used to demonstrate the techniques and the advantages of constrained mathematics. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Cooper, JA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1062-922X BN 0-7803-4778-1 J9 IEEE SYS MAN CYBERN PY 1998 BP 3206 EP 3211 PG 6 WC Computer Science, Cybernetics SC Computer Science GA BL88E UT WOS:000077033700558 ER PT B AU Monroe, DK Swanson, SE AF Monroe, DK Swanson, SE GP IEEE IEEE TI Complete method for E-bd correction by series resistance characterization SO 1998 IEEE INTERNATIONAL INTEGRATED RELIABIILTY WORKSHOP FINAL REPORT LA English DT Proceedings Paper CT 1998 International Integrated Reliability Workshop (IRW) CY OCT 12-15, 1998 CL LAKE TAHOE, CA SP IEEE Electron Devices Soc, IEEE Reliabil Soc DE capacitor; MOS; breakdown; leakage; Fowler-Nordheim ID CAPACITOR; OXIDE AB We have developed a semi-automated method for determining the series resistance profiles of dot capacitors and for obtaining corrected oxide fields at breakdown. This method is based upon a least-squares-fit of IV data, obtained from a voltage-ramp test, to the Fowler-Nordheim leakage model. The profiles provide insight into the general characteristics of series resistance. Certain features of the profiles can be associated with charge trapping and the onset of oxide breakdown. C1 Sandia Natl Labs, Reliabil Phys Dept, Albuquerque, NM 87185 USA. RP Monroe, DK (reprint author), Sandia Natl Labs, Reliabil Phys Dept, Org 1728,MS-1081,POB 5800, Albuquerque, NM 87185 USA. NR 11 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4881-8 PY 1998 BP 33 EP 38 DI 10.1109/IRWS.1998.745364 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BM43U UT WOS:000078742600007 ER PT B AU Miller, SL Rodgers, MS LaVigne, G Sniegowski, JJ Clews, P Tanner, DM Peterson, KA AF Miller, SL Rodgers, MS LaVigne, G Sniegowski, JJ Clews, P Tanner, DM Peterson, KA GP IEEE TI Failure modes in surface micromachined MicroElectroMechanical actuators SO 1998 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 36TH ANNUAL LA English DT Proceedings Paper CT 36th Annual IEEE International Reliability Physics Symposium CY MAR 31, 1996-APR 02, 1998 CL RENO, NV SP IEEE Electron Devices Soc, IEEE Reliabil Soc DE microengine; failure mechanisms; MEMS failure modes AB In order for the rapidly emerging field of MicroElectroMechanical Systems (MEMS) to meet its extraordinary expectations regarding commercial impact, issues pertaining to how they fail must be understood. We identify failure modes common to a broad range of MEMS actuators, including adhesion (stiction) and friction-induced failures caused by improper operational methods, mechanical instabilities, and electrical instabilities. Demonstrated methods to mitigate these failure modes include implementing optimized designs, model-based operational methods, and chemical surface treatments. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Miller, SL (reprint author), Sandia Natl Labs, POB 5800,Mail Stop 1080, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4400-6 PY 1998 BP 17 EP 25 DI 10.1109/RELPHY.1998.670437 PG 9 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BK90C UT WOS:000073835800003 ER PT B AU Tanner, DM Miller, WM Eaton, WP Irwin, LW Peterson, KA Dugger, MT Senft, DC Smith, NF Tangyunyong, P Miller, SL AF Tanner, DM Miller, WM Eaton, WP Irwin, LW Peterson, KA Dugger, MT Senft, DC Smith, NF Tangyunyong, P Miller, SL GP IEEE TI The effect of frequency on the lifetime of a surface micromachined microengine driving a load SO 1998 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 36TH ANNUAL LA English DT Proceedings Paper CT 36th Annual IEEE International Reliability Physics Symposium CY MAR 31, 1996-APR 02, 1998 CL RENO, NV SP IEEE Electron Devices Soc, IEEE Reliabil Soc AB Experiments have been performed on surface micromachined microengines driving load gears to determine the effect of the rotation frequency on median cycles to failure. We did observe a frequency dependence and have developed a model based on fundamental wear mechanisms and forces exhibited in resonant mechanical systems. Stressing loaded microengines caused observable wear in the rotating joints and in a few instances lead to fracture of the pin joint in the drive gear. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Tanner, DM (reprint author), Sandia Natl Labs, POB 5800,MS 1081, Albuquerque, NM 87185 USA. NR 0 TC 7 Z9 7 U1 1 U2 3 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4400-6 PY 1998 BP 26 EP 35 DI 10.1109/RELPHY.1998.670438 PG 10 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BK90C UT WOS:000073835800004 ER PT B AU Barton, DL Osinski, M Perlin, P Eliseev, PG Lee, JH AF Barton, DL Osinski, M Perlin, P Eliseev, PG Lee, JH GP IEEE TI Degradation of single-quantum well InGaN green light emitting diodes under high electrical stress SO 1998 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 36TH ANNUAL LA English DT Proceedings Paper CT 36th Annual IEEE International Reliability Physics Symposium CY MAR 31, 1996-APR 02, 1998 CL RENO, NV SP IEEE Electron Devices Soc, IEEE Reliabil Soc AB We performed a degradation study of high-brightness Nichia single-quantum well AlGaN/InGaN/GaN green light-emitting diodes (LEDs). The devices were subjected to high current electrical stress with current pulse amplitudes between 1 A and 7 A and voltages between 10 V and 70 V with a pulse length of 100 ns and a 1 kHz repetition rate. The study showed that when the current amplitude was increased above 6 A, a fast (about 1 s) degradation occurred, with a visible discharge between the p-and n-type electrodes. Subsequent failure analysis revealed severe damage to the metal contacts which lead to the formation of shorts in the surface plane of the diode. For currents smaller than 6 A, a slow degradation was observed as a decrease in optical power and an increase in the reverse current leakage. After between 24 and 100 hours however, a rapid degradation occurred which was similar to the rapid degradation observed at higher currents. The failure analysis results indicate that the degradation process begins with carbonization of the plastic encapsulation material on the diode surface which leads to the formation of a conductive path across the LED and subsequently to the destruction of the diode itself. C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Barton, DL (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, MS1081, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4400-6 PY 1998 BP 119 EP 123 DI 10.1109/RELPHY.1998.670460 PG 5 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BK90C UT WOS:000073835800019 ER PT B AU Cole, EI Tangyunyong, P Barton, DL AF Cole, EI Tangyunyong, P Barton, DL GP IEEE TI Backside localization of open and shorted IC interconnections SO 1998 IEEE INTERNATIONAL RELIABILITY PHYSICS SYMPOSIUM PROCEEDINGS - 36TH ANNUAL LA English DT Proceedings Paper CT 36th Annual IEEE International Reliability Physics Symposium CY MAR 31, 1996-APR 02, 1998 CL RENO, NV SP IEEE Electron Devices Soc, IEEE Reliabil Soc AB A new failure analysis technique has been developed for backside and frontside localization of open and shorted interconnections on ICs. This scanning optical microscopy technique takes advantage of the interactions between IC defects and localized heating using a focused infrared laser (lambda = 1340 nm). Images are produced by monitoring the voltage changes across a constant current supply used to power the IC as the laser beam is scanned across the sample. The method utilizes the Seebeck Effect to localize open interconnections and Thermally-Induced Voltage Alteration (TIVA) to detects shorts. The interaction physics describing the signal generation process and several examples demonstrating the localization of opens and shorts are described. Operational guidelines and limitations are also discussed. C1 Sandia Natl Labs, Elect Qual Reliabil Ctr, Albuquerque, NM 87185 USA. RP Cole, EI (reprint author), Sandia Natl Labs, Elect Qual Reliabil Ctr, MS 1081, Albuquerque, NM 87185 USA. NR 0 TC 1 Z9 1 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4400-6 PY 1998 BP 129 EP 136 DI 10.1109/RELPHY.1998.670462 PG 8 WC Engineering, Electrical & Electronic; Physics, Applied; Physics, Condensed Matter SC Engineering; Physics GA BK90C UT WOS:000073835800021 ER PT B AU Ashikhmin, A Litsyn, S AF Ashikhmin, A Litsyn, S GP IEEE IEEE TI Upper bounds on the size of quantum codes SO 1998 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Symposium on Information Theory CY AUG 16-22, 1998 CL MIT, CAMBRIDGE, MA SP IEEE, Informat Theory Soc, Natl Sci Fdn, NASA, USN, Off Naval Res, AT&T, Motorola, Qualcomm, Lucent Technol, Bell Lab Innovat HO MIT AB Upper bounds on the size of quantum error correcting codes are considered. We generalize the linear programming approach to the quantum case and obtain the Singleton, Hamming and first linear programming type bounds for quantum codes. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ashikhmin, A (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. EM alexei@c3serve.c3.lanl.gov; litsyn@eng.tau.ac.il NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5000-6 PY 1998 BP 351 EP 351 DI 10.1109/ISIT.1998.708956 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA BL58H UT WOS:000075932800349 ER PT B AU Ashikhmin, A Barg, A AF Ashikhmin, A Barg, A GP IEEE IEEE TI Binomial moments of the distance distribution: Bounds and applications SO 1998 IEEE INTERNATIONAL SYMPOSIUM ON INFORMATION THEORY - PROCEEDINGS LA English DT Proceedings Paper CT IEEE International Symposium on Information Theory CY AUG 16-22, 1998 CL MIT, CAMBRIDGE, MA SP IEEE, Informat Theory Soc, Natl Sci Fdn, NASA, USN, Off Naval Res, AT&T, Motorola, Qualcomm, Lucent Technol, Bell Lab Innovat HO MIT AB We study a combinatorial invariant of codes which counts the number of ordered pairs of codewords in all subcodes of a given support in a code. The main part of this work is related to deriving lower bounds on this invariant, both finite and asymptotic. These bounds are used to obtain new lower bounds on the probability of undetected error of binary codes on the BSC which improve previously known results. We also derive new asymptotic upper bounds on the exponent of undetected error and extend the region of code rates in which this exponent is tight. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Ashikhmin, A (reprint author), Univ Calif Los Alamos Natl Lab, Mail Stop P990, Los Alamos, NM 87545 USA. EM alexei@c3serve.c3.lanl.gov; abarg@research.bell-labs.com NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5000-6 PY 1998 BP 437 EP 437 DI 10.1109/ISIT.1998.709042 PG 1 WC Engineering, Electrical & Electronic SC Engineering GA BL58H UT WOS:000075932800435 ER PT B AU McMahan, MA AF McMahan, MA GP IEEE IEEE TI Cocktails and other libations - The 88-inch cyclotron radiation effects facility SO 1998 IEEE RADIATION EFFECTS DATA WORKSHOP LA English DT Proceedings Paper CT IEEE Radiation Effects Data Workshop held in Conjunction with IEEE Nuclear and Space Radiation Effects Conference CY JUL 20-24, 1998 CL NEWPORT BEACH, CA SP IEEE, Nucl & Plasma Sci Soc, Inst Elect & Electr Engineers Inc AB The 88-lnch Cyclotron at the E.O. Lawrence Berkeley National Laboratory has unique capabilities of advantage for radiation effects testing (RET) and detector calibrations for space applications. The ability to deliver from protons (low linear energy transfer (LET) and high range) to bismuth (LET = 100 MeV/mg/cm(2)), and most ions in between, makes the Cyclotron facility a versatile cosmic ray factory on Earth. In addition, the availability of "cocktail" beams of several ion species allows the luxury of testing parts over a range of LET values with one tune-up, saving time and money. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP McMahan, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5109-6 PY 1998 BP 156 EP 163 DI 10.1109/REDW.1998.731497 PG 8 WC Engineering, Aerospace; Engineering, Electrical & Electronic; Nuclear Science & Technology SC Engineering; Nuclear Science & Technology GA BM17C UT WOS:000077899800024 ER PT S AU Littlefield, RJ Macedonia, MAJCR Coleman, JD AF Littlefield, RJ Macedonia, MAJCR Coleman, JD BE Schneider, SC Levy, M McAvoy, BR TI MUSTPAC (TM) 3-D ultrasound telemedicine/telepresence system SO 1998 IEEE ULTRASONICS SYMPOSIUM - PROCEEDINGS, VOLS 1 AND 2 SE ULTRASONICS SYMPOSIUM LA English DT Proceedings Paper CT 1998 IEEE Ultrasonics Symposium CY OCT 05-08, 1998 CL SENDAI, JAPAN SP IEEE, Ultrason Ferroelect & Frequency Control Soc ID FETAL TELEMEDICINE AB MUSTPAC(TM) is a family of ultrasound telemedicine systems based on the use of 3-D (volumetric) data acquisition. Diagnostically useful scans can be taken by an operator with limited training and no ultrasound diagnostic skills, using a simple "point-and-shoot" procedure. For diagnosis, volumetric datasets are transmitted to a remote radiologist, who uses a "virtual ultrasound probe" to reslice the datasets along arbitrary planes, using familiar hand movements and seeing 2-D (planar) displays similar to those of a conventional real-time hands-on examination. Prototype MUSTPAC(TM) systems have operated in a military field hospital and on a Mt. Everest climbing expedition, and are currently being evaluated for clinical application in rural and remote environments. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Littlefield, RJ (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 8 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA SN 1051-0117 BN 0-7803-4096-5 J9 ULTRASON PY 1998 BP 1669 EP 1675 PG 7 WC Acoustics; Engineering, Electrical & Electronic SC Acoustics; Engineering GA BM87A UT WOS:000079968900371 ER PT B AU Berg, RS Winter, V AF Berg, RS Winter, V BE Ntafos, S TI Use of integrity techniques and risk assessment in system design SO 1998 IEEE WORKSHOP ON APPLICATION-SPECIFIC SOFTWARE ENGINEERING AND TECHNOLOGY (ASSET 98) - PROCEEDINGS LA English DT Meeting Abstract CT IEEE Workshop on Application-Specific Software Engineering and Technology (ASSET 98) CY MAR 26-28, 1998 CL UNIV TEXAS DALLAS, RICHARDSON, TX SP IEEE, Comp Soc, Univ Texas Dallas, Ctr Applicat Specif Syst & Software Engn HO UNIV TEXAS DALLAS C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Berg, RS (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8582-4 PY 1998 BP 60 EP 62 DI 10.1109/ASSET.1998.688234 PG 3 WC Computer Science, Software Engineering; Telecommunications SC Computer Science; Telecommunications GA BL38R UT WOS:000075345000010 ER PT B AU Jordan, SE Snell, MK Madsen, MM Smith, JS Peters, BA AF Jordan, SE Snell, MK Madsen, MM Smith, JS Peters, BA BE Medeiros, DJ Watson, EF Carson, JS Manivannan, MS TI Discrete-event simulation for the design and evaluation of physical protection systems SO 1998 WINTER SIMULATION CONFERENCE PROCEEDINGS, VOLS 1 AND 2 LA English DT Proceedings Paper CT 1998 Winter Simulation Conference on Simulation in the 21st-Century (WSC 98) CY DEC 13-16, 1998 CL WASHINGTON, D.C. AB This paper explores the use of discrete-event simulation for the design and control of physical protection systems for fixed-site facilities housing items of significant value. It begins by discussing several modeling and simulation activities currently performed in designing and analyzing these protection systems and then discusses capabilities that design/analysis tools should have. The remainder of the article then discusses in detail how some of these new capabilities have been implemented in software to achieve a prototype design and analysis tool. The simulation software technology provides a communications mechanism between a running simulation and one or more external programs. In the prototype security analysis tool, these capabilities are used to facilitate human-in-the-loop interaction and to support a real-time connection to a virtual reality (VR) model of the facility being analyzed. This simulation tool can be used for both training tin realtime mode) and facility analysis and design (in fast mode). C1 Sandia Natl Labs, Dept 5838, Albuquerque, NM 87123 USA. RP Jordan, SE (reprint author), Sandia Natl Labs, Dept 5838, Mail Stop 0780,1515 Eubank Blvd SE, Albuquerque, NM 87123 USA. RI Peters, Brett/H-4272-2011 OI Peters, Brett/0000-0003-1671-2056 NR 5 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-5133-9 PY 1998 BP 899 EP 905 PG 7 WC Computer Science, Interdisciplinary Applications; Computer Science, Software Engineering; Engineering, Multidisciplinary; Engineering, Manufacturing; Engineering, Electrical & Electronic; Transportation SC Computer Science; Engineering; Transportation GA BM30S UT WOS:000078340100122 ER PT B AU Nolan, DS Farrell, BF AF Nolan, DS Farrell, BF GP AMER METEOROL SOC AMER METEOROL SOC AMER METEOROL SOC TI The Reynolds number dependence of the flow structure and maximum windspeeds of tornado-like vortices SO 19TH CONFERENCE ON SEVERE LOCAL STORMS LA English DT Proceedings Paper CT 19th Conference on Severe Local Storms CY SEP 14-18, 1998 CL MINNEAPOLIS, MN SP Amer Meteorol Soc C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Nolan, DS (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, 1 Cyclotron Rd,50A-2152, Berkeley, CA 94720 USA. NR 11 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOCIETY PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 USA PY 1998 BP 214 EP 217 PG 4 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA BM52X UT WOS:000079026500058 ER PT B AU Smith, BW Laubscher, B Cooke, B Harlander, J AF Smith, BW Laubscher, B Cooke, B Harlander, J BE Schaepman, M Schlapfer, D Itten, K TI Pushbroom Fourier transform ultraspectral IR imaging with no moving parts: The imaging spatial heterodyne spectrometer SO 1ST EARSEL WORKSHOP ON IMAGING SPECTROSCOPY LA English DT Proceedings Paper CT 1st EARSeL Workshop on Imaging Spectroscopy CY OCT 06-08, 1998 CL UNIV ZURICH, REMOTE SENSING LAB, ZURICH, SWITZERLAND SP EARSeL HO UNIV ZURICH, REMOTE SENSING LAB ID PHOTODIODE ARRAY; SPECTROSCOPY AB Ultraspectral imaging in the thermal infrared (TIR) is currently performed with dispersive spectrometers based on prisms or gratings, or with Fourier Transform Spectrometers (FTS). The Imaging Spatial Heterodyne Spectrometer (ISHS) is a revolutionary FTS design for remote sensing (see Harlander et al. 1992 for an ISHS design in the far ultraviolet). There are several configurations of ISHS, all of which share the following characteristics: 1) no parts that move during data collection, 2) no slit, 3) high etendue, 4) pushbroom imaging, 5) ease of attaining very high spectral resolution, and 6) greatly reduced data rate compared to conventional FTSs. The last two characteristics are both due to "heterodyning" of the spatial fringe frequencies [explained below]. In one configuration of ISHS each mirror in the conventional Michelson FTS is replaced with a fixed diffraction grating. Light is deflected as a function of wavelength in opposite directions in the two arms of the interferometer, so that spatial fringes are formed by crossing of nonparallel coherent wavefronts. These fringes can be directly imaged on a two-dimensional focal plane array (FPA) detector. "Heterodyning" comes about because the designer can choose any "reference" wavenumber of light to produce no fringes in the ISHS interferometer. Wavenumbers nearby to the reference produce fringes whose spatial frequency is proportional to the difference between the wavenumber and the reference. In contrast, the wavenumber of light that produces no fringes in the Michelson FTS is zero. The ISHS attains high spectral resolution in a small package by selection of appropriate grating spacing and focal length for the imaging optics. It attains economical data rates by needing fewer samples, because the fringe frequencies are low, for the same spectral and spatial resolution as a conventional FTS. The FOV is pushbroomed along the ground to accumulate interferograms for all pixels simultaneously. Each time the FPA is read out, interferograms are completed for one line (the trailing line) of ground scene pixels. Because of reduced sampling requirements, interferograms can be completed in much less than a second from an airborne or satellite platform (without the pointing and tracking complexities of staring). Because of the low data rate a broad-area search ISHS instrument could be coupled to an ultrafast on-board processor for realtime mapping of ultraspectral signatures. Comparisons: In comparison to the conventional FTS, the ISHS has: 1) no parts that move during data collection, 2) pushbroom imaging, 3) approximately the same signal-to-noise ratio (S/N) for equivalent conditions, 4) much lower data rate. In comparison to dispersive spectrometers, the ISHS has: 1) higher etendue, and 2) much smaller size for equally high spectral resolution, 3) approximately the same S/N except in cases where the entire dispersive spectrometer is cryogenically cooled, and 4) full-field imaging for ease in jitter and motion reconstruction from in-scene analysis. Current program: Los Alamos has constructed a prototype ISHS for ground-based observations with the following features: Wavelength band, any 100 cm(-1) between 870 and 1250 cm(-1); spectral resolution, 1 cm(-1); telescope aperture, 300 mm; field of view, 0.69 degrees; system f/number, 2.1; interferometer aperture, 45 mm; focal plane array (FPA), 256x256 pixels, HgCdTe; S/N approximately 300. The wavelength band is limited by the number of pixels in the FPA and by the optical quality of the objective telescope. We will present current results as well as concepts for remote sensing applications of ISHS in other wavelength bands. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Smith, BW (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 16 TC 0 Z9 0 U1 2 U2 2 PU EUROPEAN ASSOC REMOTE SENSING LABORATORIES PI VERSAILLES PA LAB TELEDETECT INRA-INA PG, 78000 VERSAILLES, FRANCE BN 2-908885-22-0 PY 1998 BP 53 EP + PG 4 WC Remote Sensing; Spectroscopy SC Remote Sensing; Spectroscopy GA BR38E UT WOS:000166270600007 ER PT S AU Lewinsohn, CA Eldridge, JI Jones, RH AF Lewinsohn, CA Eldridge, JI Jones, RH BE Bray, D TI Techniques for measuring interfacial recession in CFCC's and the implications on subcritical crack growth SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID REINFORCED CERAMIC COMPOSITES; BRITTLE MATRIX COMPOSITES; OXIDATION; KINETICS AB Interfacial properties play a significant role in determining the mechanical response of continuous fiber reinforced, ceramic composites. Increases in fracture toughness, relative to the monolithic matrix material, and non-catastrophic failure modes are dependent on fiber matrix debonding during crack propagation. The most common method employed to promote debonding at the fiber matrix interface is to incorporate an interphase material. Unfortunately, most interphase materials are susceptible to degradation when exposed to oxidizing environments. Degradation of the interphase also degrades the composite properties and may influence the failure mode. In many cases, oxidation may result in the loss of interphase material. Development of composites with degradation-resistant interphases requires a technique to measure the extent of interphase recession. This paper will demonstrate the use of a fiber push-in technique to determine interphase recession distances for carbon interphases and will compare the relative advantages of this method with optical measurements and TGA. C1 Battelle Mem Inst, Pacific NW Labs, Richland, WA 99352 USA. RP Lewinsohn, CA (reprint author), Battelle Mem Inst, Pacific NW Labs, POB 999, Richland, WA 99352 USA. NR 13 TC 9 Z9 9 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 19 EP 26 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200003 ER PT S AU Shen, TD Schwarz, RB Sickafus, KE Ustundag, E AF Shen, TD Schwarz, RB Sickafus, KE Ustundag, E BE Bray, D TI Vanadium/MgAl2O4 composites for hostile environment applications - Part I: Processing SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Metal-ceramic composites of vanadium and magnesio-aluminate (spinel) were developed for applications in high radiation environments. A number of powder processing routes were used to obtain composites with different properties. These are (1) ball milling mixtures of commercial powders; (2) in situ displacement reactions during ball milling; and (3) same as (2) with the addition of a small amount of reducing metallic elements. The ball milled powders mere consolidated by hot isostatic pressing. This talk discusses the processing routes and the microstructures obtained. The following talk (Part II) in this conference presents the properties of the composites. C1 Univ Calif Los Alamos Natl Lab, MST Div, Los Alamos, NM 87545 USA. RP Shen, TD (reprint author), Univ Calif Los Alamos Natl Lab, MST Div, Los Alamos, NM 87545 USA. RI Ustundag, Ersan/C-1258-2009 OI Ustundag, Ersan/0000-0002-0812-7028 NR 10 TC 0 Z9 0 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 155 EP 162 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200018 ER PT S AU Routbort, JL Goretta, KC Doshi, R Richards, VL Krumpelt, M Wolfenstine, J de Arellano-Lopez, AR AF Routbort, JL Goretta, KC Doshi, R Richards, VL Krumpelt, M Wolfenstine, J de Arellano-Lopez, AR BE Bray, D TI Mechanical properties of Ce0.9Gd0.1O2-x and Ce0.9Gd0.1O2-x+Al2O3 composites SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID FRACTURE-TOUGHNESS; CREEP; ZIRCONIA; CERAMICS AB The room-temperature elastic moduli, fracture strength, and fracture toughness of dense, fine-grained, pure Ce0.9Gd0.1O1.95 and composites containing 1.3 and 9.1 wt.% Al2O3 were investigated. Addition of 9.1 wt.% Al2O3 to Ce0.9Gd0.1O1.95 changed the fracture mode from intergranular to transgranular and increased room-temperature fracture strength from 65 to 125 MPa and fracture toughness from 1.3 to 1.6 MPam(1/2). In addition, steady-state compressive creep was measured for Ce0.9Gd0.1O1.95 and the Ce0.9Gd0.1O2-x + 9.1 wt.% Al2O3 composite. The stress exponent approximate to 1.3 and the activation energy approximate to 480 kJ/mole for Ce0.9Gd0.1O1.95 suggested diffusional flow controlled by the cations. There was no difference in creep rate between Ce0.9Gd0.1O2-x and the composite. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Routbort, JL (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. OI R. de Arellano Lopez, Antonio/0000-0002-7443-0244 NR 21 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 189 EP 196 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200022 ER PT S AU Radhakrishnan, R Williams, J Kramer, M Akinc, M AF Radhakrishnan, R Williams, J Kramer, M Akinc, M BE Bray, D TI Comparison of the sintering behavior of SHS and arc melted Ti5Si3 SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID COMBUSTION SYNTHESIS; SILICIDE AB Single phase Ti5Si3 was synthesized by SHS and are-melting of elemental powders. The synthesized powders were ground and classified to < 20 mu m. After sintering at 1800 degrees C or 1900 degrees C, in an argon atmosphere, the densities were found to be similar for both SHS and are-melted materials. However, when the form of the reactants for are-melting were changed from powders to solid lumps, lower sintered densities were obtained. The difference in sintered densities was attributed to the oxygen content. To support this hypothesis, Ti5Si3 was intentionally doped with oxygen and sintered under identical conditions. Ti5Si3 doped with oxygen had the highest sintered density among all the samples investigated. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Radhakrishnan, R (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 12 TC 3 Z9 3 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 381 EP 388 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200042 ER PT S AU Park, YS Butt, DP Castro, R Hollis, K Petrovic, J AF Park, YS Butt, DP Castro, R Hollis, K Petrovic, J BE Bray, D TI Viability and degradation of molybdenum disilicide materials in molten glass environments SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID SILICON-CARBIDE; OXIDATION AB The durability and degradation mechanisms of MoSi2 materials, compared to other refractory materials, were investigated for industrial glass applications. The corrosion behavior was assessed by measuring dimensional changes above, at, and below the molten glass line. Tests were performed at temperatures ranging from 1000 degrees C to 1550 degrees C for 0.5 to 1510 hours under dynamic and static conditions. Mechanisms were evaluated using SEM, EDS, EMPA, XRD, and TEM. Test results show that MoSi2 is superior to other test refractories except ACZS and ZrO2. MoSi2 is comparable to ACZS and ZrO2 above and below the glass line due to the formation of protective SiO2 and Mo-rich layers, respectively. However corrosion of MoSi2 at the glass line is more rapid due to dissolution of SiO2 and simultaneous sublimation of Mo oxides. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Park, YS (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 16 TC 1 Z9 1 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 389 EP 395 PG 7 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200043 ER PT S AU Chu, F Thoma, DJ AF Chu, F Thoma, DJ BE Bray, D TI Processing and properties of Mo5Si3 single crystals SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Ultra-high temperature structural ceramics Mo5Si3 has been studied for materials processing and physical and mechanical properties. Single crystal Mo5Si3 has been synthesized by both optical floating zone and Czochralski methods. Thermal and elastic properties of Mo5Si3 single crystals were experimentally measured. Results show that Mo5Si3 is significantly anisotropic along a and c directions in thermal expansion. Single crystal elastic moduli indicate that it has less elastic anisotropy and lower shear moduli than some silicides. Room temperature Vickers indentation tests on (100) and (001) planes have been performed in different indenter diagonal orientations and the corresponding deformation and fracture modes have been revealed. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Chu, F (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Mail Stop G755, Los Alamos, NM 87545 USA. NR 8 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 413 EP 420 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200046 ER PT S AU Cook, BA Zelle, S Kramer, MJ AF Cook, BA Zelle, S Kramer, MJ BE Bray, D TI High temperature electrical resistivity and oxidation resistance of Mo-Si-B prepared by mechanical alloying SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID TRANSITION; SILICON AB Alloys based on the Mo5Si3-B benchmark were prepared by mechanical alloying (MA) of elemental powders and consolidated by vacuum hot pressing. The effect of two different types of milling media were examined; hardened tool steel and tungsten carbide. The evolution of the milling process was followed by X-ray diffraction and TEM. The intensity of the diffraction peaks corresponding to elemental silicon were reduced to background noise after as little as two hours of milling. Powders subject to MA for as little as one hour exhibited high defect density and showed evidence of diffusion of silicon into molybdenum. After 15 hours, amorphous and crystalline nanophased grains containing Mo and Si were observed. A systematic reduction in the bcc lattice parameter of Mo was observed, suggestive of substitutional diffusion of Si onto Mo sites. Densities greater than 95% of theoretical were obtained on powders consolidated at 1300 degrees C. Electrical resistivity measurements on specimens taken from the consolidated compacts gave results comparable to that of are melted and sintered materials. Results of preliminary oxidation tests at 1100 degrees C indicate that a continuous protective scale is formed but that the presence of contamination From the grinding media affects the chemistry of the scale. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Cook, BA (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 429 EP 436 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200048 ER PT S AU Tiegs, TN Menchhofer, PA Plucknett, KP Becher, PF Thomas, CB Liaw, PK AF Tiegs, TN Menchhofer, PA Plucknett, KP Becher, PF Thomas, CB Liaw, PK BE Bray, D TI Comparison of sintering behavior and properties of aluminide-bonded ceramics SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID BINDER PHASE; COMPOSITES AB Recent studies have examined new materials that are based on a matrix consisting of a hard carbide phase and an aluminide (e.g., Ni3Al, FeAl) binder phase. Initial results show that these composites have fracture toughness values comparable to the very high values obtained in the best commercial cobalt-bonded WC composites. In addition, these composites can also exhibit extremely high fracture strengths (e.g,, in excess of 1 GPa), and these strength levels are retained at temperatures up to 800 degrees C. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Tiegs, TN (reprint author), Oak Ridge Natl Lab, POB 2008, Oak Ridge, TN 37831 USA. RI Menchhofer, Paul/E-1529-2017 OI Menchhofer, Paul/0000-0001-9475-314X NR 13 TC 1 Z9 1 U1 1 U2 4 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 447 EP 455 PG 9 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200050 ER PT S AU Biner, SB AF Biner, SB BE Bray, D TI Creep deformation behavior of SiC particulate reinforced aluminum composite SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID BOUNDARY CAVITATION AB In this study the creep deformation and creep rupture behavior of 20vol% SIC particulate reinforced 2014 aluminum alloy and 1100 aluminum alloy were studied. The results indicate that the stress enhancement resulting from grain sliding, grain rotation in the matrix and interface cavitation at the reinforcements play a significant role in the creep deformation behavior of the composite. When these effects and threshold stress concepts are considered together, the creep data for the composite unify with the creep data that are seen for the 1100 aluminum alloy. C1 Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Biner, SB (reprint author), Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. NR 9 TC 1 Z9 1 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 475 EP 482 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200053 ER PT S AU Sixta, ME MoberlyChan, WJ De Jonghe, LC AF Sixta, ME MoberlyChan, WJ De Jonghe, LC BE Bray, D TI Grain boundaries, oxidation, and strength of heat treated SiC SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID TOUGHENED SILICON-CARBIDE; B-C ADDITIONS; KINETICS; BORON AB After thermomechanical processing to develop a tough ceramic microstructure, additional thermal processing often is desirable to alter surface conditions such as for joining applications and/or for improving corrosion resistance. These subsequent heat treatments can change the near-surface fracture path of the SiC from a tough intergranular mode to a transgranular mode. However, the bulk strength degradation can be minimized while improving the oxidation resistance by a factor of ii. The role of the grain boundaries is investigated with SEM, HRTEM, and EDS. Subtle changes in the grain boundary chemistry and structure dramatically influence strength and oxidation. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Sixta, ME (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 18 TC 0 Z9 0 U1 1 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 509 EP 516 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200057 ER PT S AU Sun, JG Easler, TE Szweda, A Pillai, TAK Deemer, C Ellingson, WA AF Sun, JG Easler, TE Szweda, A Pillai, TAK Deemer, C Ellingson, WA BE Bray, D TI Thermal imaging and air-coupled ultrasound characterization of a continuous fiber ceramic composite SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB SYLRAMIC(TM) continuous fiber ceramic-matrix composites (Nicalon(TM) fiber/SiNC matrix) were fabricated by Dow Coming Corporation with the polymer-impregnation and pyrolysis (PIP) process. The composite macrostructure and its uniformity, and the completeness of infiltration during processing were studied as a function of number of PIP cycles. Two nondestructive evaluation (NDE) methods, i.e., infrared thermal imaging and air-coupled ultrasound (UT), were used to investigate flat composite panels of two thicknesses and various sizes. The thermal imaging method provided two-dimensional (2D) images of through-thickness thermal diffusivity distributions, and the air-coupled UT method provided 2D images of through-thickness ultrasonic transmission of the panel components. Results from both types of NDEs were compared at various PIP cycles during fabrication of the composites. A delaminated region was clearly detected and its progressive repair was monitored during processing. The NDE data were also correlated to results obtained from destructive characterization. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Sun, JG (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 533 EP 540 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200060 ER PT S AU Clausen, B Ustundag, E Rangaswamy, P Bourke, MAM Sass, SL Barbieri, TJ AF Clausen, B Ustundag, E Rangaswamy, P Bourke, MAM Sass, SL Barbieri, TJ BE Bray, D TI Investigations of the reduction of NiAl2O4 - II: X-ray diffraction studies SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID METAL-CERAMIC MICROSTRUCTURES; AL-O SYSTEM AB The volume shrinkage that accompanies the reduction of NiAl2O4 to a metal-ceramic composite of nickel and alumina leads to residual stress buildup. We have attempted to utilize these stresses to "temper" a ceramic component by placing it under compression. To prove the concept, we produced model specimens which we investigated using X-ray diffraction. Employing the conventional "d vs. sin(2)Psi" method to map surface stresses, the results obtained from these measurements are presented together with finite element calculation predictions used to interpret experimental stress data. C1 Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering, Los Alamos, NM 87545 USA. RP Clausen, B (reprint author), Univ Calif Los Alamos Natl Lab, Manuel Lujan Jr Neutron Scattering, MS H805, Los Alamos, NM 87545 USA. RI Ustundag, Ersan/C-1258-2009; Clausen, Bjorn/B-3618-2015 OI Ustundag, Ersan/0000-0002-0812-7028; Clausen, Bjorn/0000-0003-3906-846X NR 5 TC 0 Z9 0 U1 0 U2 2 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 557 EP 564 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200063 ER PT S AU Sun, JG Petrak, DR Pillai, TAK Deemer, C Ellingson, WA AF Sun, JG Petrak, DR Pillai, TAK Deemer, C Ellingson, WA BE Bray, D TI Nondestructive evaluation and characterization of damage and repair for continuous fiber ceramic composite panels SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: A SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Continuous fiber ceramic matrix composites are currently being developed for a variety of high-temperature applications. Because of the high costs of making these components, minor damage incurred during manufacturing or operation must be repaired in order to extend the life of the components. In this study, five ceramic-grade Nicalon(TM)-fiber/SiNC-matrix composite panels were intentionally damaged with a pendulum-type impactor during an impact test. The damaged panels were then repaired at Dow Coming Corporation. Three nondestructive evaluation (NDE) methods were used to study the characteristics of the panels after the damage and again after the panels were repaired. The NDE methods were Xray radiography, infrared thermal imaging, and air-coupled ultrasound. The results showed that the impact test induced various types of damage in the panels. The NDE data that were obtained by the three NDE methods were correlated with each other. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Sun, JG (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 5 Z9 5 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 3 BP 615 EP 622 PG 8 WC Materials Science, Ceramics; Materials Science, Characterization & Testing; Materials Science, Composites SC Materials Science GA BN01Q UT WOS:000080406200069 ER PT S AU Lewinsohn, CA Henager, CH Jones, RH AF Lewinsohn, CA Henager, CH Jones, RH BE Bray, D TI Environmentally induced time-dependent failure mechanisms in CFCCs at elevated temperatures. SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID CERAMIC-MATRIX COMPOSITES; OXIDATION; NICALON; EMBRITTLEMENT; CARBON AB The results of several studies suggest that a variety of mechanisms exist for time-dependent failure in CFCCs at elevated temperatures. The failure mechanisms of CFCCs at elevated temperatures when oxidation processes occur during deformation are presented and discussed in the framework of a "Failure Mechanism Map". In particular, the transition between the oxidation embrittlement mechanism (OEM) and the interfacial removal mechanism (IRM) is discussed with respect to oxygen concentration, exposure temperature, and carbon interphase thickness. Experimental data and modeling from studies, using flexural loading, at PNNL is combined with observations reported by others to produce the map. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Lewinsohn, CA (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. OI Henager, Chuck/0000-0002-8600-6803 NR 14 TC 14 Z9 14 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 11 EP 18 PG 8 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400002 ER PT S AU Andrews, MJ Wereszczak, AA Breder, K Ferber, MK Kirkland, TP AF Andrews, MJ Wereszczak, AA Breder, K Ferber, MK Kirkland, TP BE Bray, D TI Investigations of the Weibull modulus as a function of stressing rate SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB A major factor that inhibits the implementation of silicon nitride (Si3N4) in load bearing applications, such as exhaust valves for diesel engines [1-2], is the successful utilization and demonstration of design and life prediction algorithms. Life prediction algorithms [3-4] model time dependent failure due to subcritical crack growth using a power-law relationship within a Weibull distribution. The probabilistic prediction assumes that the Weibull modulus is invariant to the stressing rate or time. Experimental data for a recently commercialized Si3N4 have shown that surface flaws were more susceptible to slow crack growth (SCG) than volume flaws. Furthermore, within a 95 percent confidence band, the Weibull modulus significantly decreased for surface-induced failures as the stressing rate decreased. The study found that surface flaw limiting failure strength correlated well with the calculated probability of failure based on the reduced stressing rate. The volume-induced failures, which were less susceptible to SCG, had no significant decrease in the Weibull modulus. In addition, the failure strength limited by volume flaws did not correlate as well with the calculated probability of failure based on the reduced stressing rate. Using AlliedSignal's life prediction codes to estimate the failure probability of a ceramic diesel valve from the same data resulted in the same Weibull moduli behavior; namely, as the stressing rate decreased, surface failures had greater influence in decreasing the Weibull modulus than volume failures. However, the findings of this study do not have strong statistical significance due to the insufficient number of censored failure strengths used in the analysis, and will require further investigations when additional censored data becomes available. C1 Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Andrews, MJ (reprint author), Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RI Wereszczak, Andrew/I-7310-2016 OI Wereszczak, Andrew/0000-0002-8344-092X NR 7 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 79 EP 87 PG 9 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400009 ER PT S AU Breder, K Wereszczak, AA Andrews, MJ AF Breder, K Wereszczak, AA Andrews, MJ BE Bray, D TI Exploration of the Weibull modulus as a function of surface preparation and flexure testing conditions SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Weibull characteristic strength and modulus were studied as a function of machining severity and orientation. The characteristic strength decreased as machining conditions were more aggressive, and longitudinally machined specimens were consistently stronger than transversely machined specimens. The Weibull modulus did not vary systematically with machining conditions, but after pooling data from sets machined under identical conditions, a low Weibull modulus and a poor fit to the Weibull distribution was obtained. The results showed that the lack of reliability of the machining process effectively decreased the Weibull modulus, a critical parameter to be used in the life prediction of machined components. C1 Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RP Breder, K (reprint author), Oak Ridge Natl Lab, High Temp Mat Lab, Oak Ridge, TN 37831 USA. RI Wereszczak, Andrew/I-7310-2016 OI Wereszczak, Andrew/0000-0002-8344-092X NR 12 TC 5 Z9 5 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 89 EP 97 PG 9 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400010 ER PT S AU Biner, SB AF Biner, SB BE Bray, D TI Bridging behavior at creep regime SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL ID CRACK-GROWTH; COMPOSITES; CAVITATION; CERAMICS; MODEL AB In this study, the growth behavior of the bridged cracks in the creep regime is investigated numerically. In the analysis, crack growths resulting from growth creep cavities with diffusional and dislocation assisted mechanisms are fully accounted for. The results indicate that the bridging tractions significantly relax even with the creep deformation of the composite alone. In contrast to homogeneous cracks, the cavities grow at comparably high rates to each other ahead of the bridged cracks at creep regime. C1 Iowa State Univ, Ames Lab, Ames, IA 50011 USA. RP Biner, SB (reprint author), Iowa State Univ, Ames Lab, Ames, IA 50011 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 135 EP 142 PG 8 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400015 ER PT S AU Unal, O Sordelet, DJ Barnard, DJ Akinc, M AF Unal, O Sordelet, DJ Barnard, DJ Akinc, M BE Bray, D TI Strength measurement of thick brittle coatings on metals SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Thick plasma sprayed Al2O3 and ZrO2 coatings were prepared on Al-alloy substrates to determine their strength by the strength of materials approach with the assumption that they are elastic and well bonded at the interface. An analytical relationship between the critical (failure) load and the failure stress was derived as a function of geometric parameters and elastic modulus ratio of coating and substrate. The loading curves of the specimens revealed distinct regions due to brittle fracture of the coatings. Experimentally determined failure loads were used to calculate the strength values for the coatings. C1 Ames Lab, Ames, IA 50011 USA. RP Unal, O (reprint author), Ames Lab, Ames, IA 50011 USA. NR 3 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 283 EP 291 PG 9 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400032 ER PT S AU Singh, JP Sutaria, M Chopra, A AF Singh, JP Sutaria, M Chopra, A BE Bray, D TI Thermomechanical behavior of plasma-sprayed zirconia thermal barrier coatings SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB The effect of coating porosity and thickness on the resistance to damage of yttria stabilized zirconia thermal barrier coatings in an oxidizing environment by thermal cycling was evaluated. Hardness and elastic modulus of an as-processed porous coating were lower than those of a dense coating and the porous coating failed after fewer thermal cycles. Similarly, specimen with a thicker coating failed after fewer thermal cycles than specimen with a thinner coating. The earlier failure of the porous coating is due to lower fracture toughness and enhanced oxidation of the coating/substrate interface, whereas, the earlier failure of the thick coating is due to higher thermal transient stresses that developed in the coating during thermal cycling. Generally, an increase in coating density led to initial increase in both hardness and elastic modulus with increasing thermal cycles. However, hardness and density gradually decreased as the number of thermal cycles increased because of microcracks formation and growth. Microscopic observations indicated that the formation of multiple microcracks and their subsequent growth and coalescence led to final coating failure. C1 Argonne Natl Lab, Div Energy Technol, Argonne, IL 60439 USA. RP Singh, JP (reprint author), Argonne Natl Lab, Div Energy Technol, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 313 EP 321 PG 9 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400035 ER PT S AU Youngblood, GE Jones, RH Morscher, GN Scholz, R Kohyama, A AF Youngblood, GE Jones, RH Morscher, GN Scholz, R Kohyama, A BE Bray, D TI Irradiation creep of advanced SiC-based fibers SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Continuous fiber-reinforced SiCf/SiC composites have low residual radioactivity and promising high temperature mechanical properties which make them attractive for applications in advanced fusion energy systems. For potential composite applications in the 600-1000 degrees C fusion relevant temperature range, a temperature range where thermal creep generally is insignificant in SiC or in advanced SiC fibers, irradiation-enhanced creep (IEC) may be important. In situ IEC tests were conducted in torsion on SCS-6 SiC fiber irradiated with 14 MeV deuterons to relatively low doses (0.06 dpa) at 450, 600 and 800 degrees C. The steady-state torsional creep rate depended linearly on stress and particle flux and surprisingly increased as the irradiation temperature decreased. A bend stress relaxation (BSR) fiber creep test has been adopted to further examine IEC during neutron irradiation in a reactor to high doses (>10 dpa). Reference 1 and 100 hr. thermal BSR creep test results were obtained for selected fibers (Sylramic, Hi Nicalon S, Hi Nicalon, Nicalon CG and Tyranno E) and are compared to irradiation dimensional stability tests for these fibers. C1 Pacific NW Natl Lab, Richland, WA 99352 USA. RP Youngblood, GE (reprint author), Pacific NW Natl Lab, Richland, WA 99352 USA. NR 10 TC 3 Z9 3 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 341 EP 346 PG 6 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400039 ER PT S AU Petrovic, JJ McClellan, KJ Kise, CD Hoover, RC Scarborough, WK AF Petrovic, JJ McClellan, KJ Kise, CD Hoover, RC Scarborough, WK BE Bray, D TI Functionally graded boron carbide SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Fabrication techniques were developed for producing graded porosity B4C, and for producing aluminum-B4C and epoxy-B4C functionally graded materials. The key fabrication aspect was obtaining the graded porosity B4C. The feasibility of producing graded porosity B4C using a grading of carbon densification aid produced from a gradient of furfuryl alcohol carbon precursor was demonstrated. This approach is quite promising, but it was not optimized in the present investigation. Graded porosity B4C materials were produced by a layering approach using different size distributions of B4C powders in the green state, and then densifying the layered assembly by hot pressing at 1900 degrees C. The hardness of uninfiltrated graded B4C, aluminum infiltrated B4C, and epoxy infiltrated B4C was observed to be similar. C1 Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. RP Petrovic, JJ (reprint author), Univ Calif Los Alamos Natl Lab, Div Mat Sci & Technol, Los Alamos, NM 87545 USA. NR 5 TC 5 Z9 5 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 387 EP 393 PG 7 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400045 ER PT S AU Neuman, AD Blacic, MJ Platero, M Romero, RS McClellan, KJ Petrovic, JJ AF Neuman, AD Blacic, MJ Platero, M Romero, RS McClellan, KJ Petrovic, JJ BE Bray, D TI Mechanical properties of melt-derived erbium oxide SO 22ND ANNUAL CONFERENCE ON COMPOSITES, ADVANCED CERAMICS, MATERIALS, AND STRUCTURES: B SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures CY JAN 20-24, 1998 CL COCOA BEACH, FL AB Erbium oxide (Er2O3) is a rare earth oxide that is chemically and thermally stable and has a melting point of 2430 OC. There is relatively little information available regarding single crystal growth of erbia or the properties of erbia. In this study, erbia single crystals have been grown in a Xenon Optical Floating Zone Unit XeOFZ capable of melting materials at temperatures up to 3000 degrees C. Erbia was melt synthesized in the XeOFZ unit in a containerless fashion, proving for little chance of contamination. Crystals were grown in compressed air, inert, oxidizing, and reducing atmospheres. A recurring problem with melt synthesis of erbia is the appearance of "flakes" at the edges of the melt zone during growth; these flakes disrupt the growth process. The processing details, along with an initial survey of the physical properties of erbia single crystals, are discussed. C1 Univ Calif Los Alamos Natl Lab, Grp NMT8, Los Alamos, NM 87544 USA. RP Neuman, AD (reprint author), Univ Calif Los Alamos Natl Lab, Grp NMT8, POB 1663, Los Alamos, NM 87544 USA. NR 11 TC 4 Z9 4 U1 1 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 4 BP 423 EP 429 PG 7 WC Materials Science, Ceramics; Materials Science, Composites SC Materials Science GA BN01R UT WOS:000080406400049 ER PT B AU Clark, D Larsen, E Katz, S AF Clark, D Larsen, E Katz, S GP AFS AFS TI Neural net implementations of the Cupola Process Model SO 2ND INTERNATIONAL CUPOLA CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd International Cupola Conference CY OCT 07-09, 1998 CL CINCINNATI, OH SP Amer Foundrymens Soc, Amer Coke & Coal Chem Inst, Iron Casting Res Inst AB The Cupola Process Model developed in recent years provides a first-principles calculation of the steady-state operation of the cupola furnace. This model takes several minutes to calculate a particular steady state condition for the cupola, but the results can also be represented by neural networks trained on a series of model input/output sets. These representations have the advantage of very rapid calculation and accurate interpolation between the discrete sets of model data, and they are useful in producing graphical user interfaces for scientific and economic analysis, cupola design, and the presentation of data to cupola operators. They are also a step towards more sophisticated automatic control of cupola melting. C1 Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. RP Clark, D (reprint author), Idaho Natl Engn Lab, Idaho Falls, ID 83415 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU AMER FOUNDRYMENS SOC PI DES PLAINES PA GOLF AND WOLF RDS, DES PLAINES, IL 60016 USA PY 1998 BP 141 EP 151 PG 11 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BR97R UT WOS:000168248300011 ER PT B AU King, P AF King, P GP AFS AFS TI Experimentation in industrial cupolas SO 2ND INTERNATIONAL CUPOLA CONFERENCE PROCEEDINGS LA English DT Proceedings Paper CT 2nd International Cupola Conference CY OCT 07-09, 1998 CL CINCINNATI, OH SP Amer Foundrymens Soc, Amer Coke & Coal Chem Inst, Iron Casting Res Inst AB There are two areas which impact the quality of the information obtained from experiments performed in an operating cupola. The first has to do with the means of obtaining the desired information - the available data acquisition system. Without a reliable method of obtaining useful data, any experiment will give limited or questionable results. The second has to do with the design of the experiments themselves. Experimentation in cupola furnaces is costly, therefore carefully designed and statistically valid experiments that produce substantial amounts of useful information with minimum disruption to the quality of iron produced are a requirement. This paper addresses these aspects of experimentation in an operating industrial cupola and describes methods of interpreting the data to obtain meaningful results. C1 US DOE, Albany Res Ctr, Washington, DC 20585 USA. RP King, P (reprint author), US DOE, Albany Res Ctr, Washington, DC 20585 USA. NR 17 TC 0 Z9 0 U1 0 U2 0 PU AMER FOUNDRYMENS SOC PI DES PLAINES PA GOLF AND WOLF RDS, DES PLAINES, IL 60016 USA PY 1998 BP 153 EP 164 PG 12 WC Metallurgy & Metallurgical Engineering SC Metallurgy & Metallurgical Engineering GA BR97R UT WOS:000168248300012 ER PT S AU Bisset, KR AF Bisset, KR GP IEEE COMP SOC TI An adaptive synchronization protocol for parallel discrete event simulation SO 31ST ANNUAL SIMULATION SYMPOSIUM, PROCEEDINGS SE PROCEEDINGS OF THE ANNUAL SIMULATION SYMPOSIA LA English DT Proceedings Paper CT 31st Annual Simulation Symposium CY APR 05-09, 1998 CL BOSTON, MA SP Soc Comp Simulat Int AB Simulation, especially discrete event simulation (DES), is used in a variety of disciplines where numerical methods are difficult or impossible to apply. One problem with this method is that a sufficiently detailed simulation may take hours or days to execute, and multiple runs may be needed in order to generate the desired results. Parallel discrete event simulation (PDES) has been explored for many years as a method to decrease the time taken to Execute a simulation. Many protocols have been developed which work well for particular types of simulations, bur perform poorly when used for other types of simulations. Often it is difficult to know a priori whether a particular protocol is appropriate Sor a given problem. in this work, an adaptive synchronization method (ASM) is developed which works well an an entire spectrum of problems. The ASM determines, using an artificial neural network (ANN), the likelihood that a particular event is safe to process. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87545 USA. RP Bisset, KR (reprint author), Univ Calif Los Alamos Natl Lab, TSA 5,MS F602, Los Alamos, NM 87545 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1080-241X BN 0-8186-8418-6 J9 PROC ANNU SIMUL SYMP PY 1998 BP 26 EP 33 DI 10.1109/SIMSYM.1998.668421 PG 8 WC Computer Science, Interdisciplinary Applications; Computer Science, Theory & Methods SC Computer Science GA BK94T UT WOS:000073924800004 ER PT B AU Parmeter, JE Linker, KL Rhykerd, CL Bouchier, FA Hannum, DW AF Parmeter, JE Linker, KL Rhykerd, CL Bouchier, FA Hannum, DW BE Sanson, LD TI Development of a trace explosives detection portal for personnel screening SO 32ND ANNUAL 1998 INTERNATIONAL CARNAHAN CONFERENCE ON SECURITY TECHNOLOGY LA English DT Proceedings Paper CT 32nd Annual International Carnahan Conference on Security Technology CY OCT 12-14, 1998 CL ALEXANDRIA, VA SP IEEE, Lexington Sect, IEEE, Aerosp & Electr Syst Soc, Chung Shan Inst Sci & Technol, Natl Chiao Tung Univ AB We discuss the development, design, and operation of a walk-through trace detection portal designed to screen personnel for explosives. Developed at Sandia National Laboratories (SNL) with primary funding from the Federal Aviation Administration (FAA) and additional support from the Department of Energy Office of Safeguards and Security, this portal is intended primarily for use in airport terminals and in other localities where a very high throughput of pedestrian traffic is combined with stringent security requirements. The portal is capable of detecting both vapor and particulate contamination, with the collection of explosive material being based upon the entrainment of that material in air flows over the body of the person being screened. This portal is capable of detecting high explosives of interest to the FAA. We discuss the results of field testing of the portal in the Albuquerque international Airport in September, 1997 and more recent steps towards commercialization of the portal. C1 Sandia Natl Labs, Dept 5848, Albuquerque, NM 87185 USA. RP Parmeter, JE (reprint author), Sandia Natl Labs, Dept 5848, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4536-3 PY 1998 BP 47 EP 49 DI 10.1109/CCST.1998.723764 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA BL81S UT WOS:000076808100006 ER PT B AU Hicks, MJ Snell, MS Sandoval, JS Potter, CS AF Hicks, MJ Snell, MS Sandoval, JS Potter, CS BE Sanson, LD TI Cost and performance analysis of physical protection systems - A case study SO 32ND ANNUAL 1998 INTERNATIONAL CARNAHAN CONFERENCE ON SECURITY TECHNOLOGY LA English DT Proceedings Paper CT 32nd Annual International Carnahan Conference on Security Technology CY OCT 12-14, 1998 CL ALEXANDRIA, VA SP IEEE, Lexington Sect, IEEE, Aerosp & Electr Syst Soc, Chung Shan Inst Sci & Technol, Natl Chiao Tung Univ AB Design and analysis of physical protection systems requires 1) identification of mission critical assets; 2) identification of potential threats that might undermine mission capability; 3) identification of the consequences of loss of mission-critical assets (e.g., time and cost to recover required capability and impact on operational readiness); and 4) analysis of the effectiveness of physical protection elements. CPA-Cost and Performance Analysis-addresses the fourth of these four issues. CPA is a methodology that joins Activity Based Cost estimation with performance-based analysis of physical protection systems. CPA offers system managers an approach that supports both tactical decision making and strategic planning. Current exploratory applications of the CPA methodology address analysis of alternative conceptual designs. Hypothetical data is used to illustrate this process. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Hicks, MJ (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4536-3 PY 1998 BP 79 EP 84 DI 10.1109/CCST.1998.723770 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BL81S UT WOS:000076808100012 ER PT B AU Pritchard, DA White, RL Adams, DG Krause, E Fox, ET Ladd, MD Heintzleman, RE Sprauer, PC MacEachin, JJ AF Pritchard, DA White, RL Adams, DG Krause, E Fox, ET Ladd, MD Heintzleman, RE Sprauer, PC MacEachin, JJ BE Sanson, LD TI Test and evaluation of panoramic imaging security sensor for force protection and facility security SO 32ND ANNUAL 1998 INTERNATIONAL CARNAHAN CONFERENCE ON SECURITY TECHNOLOGY LA English DT Proceedings Paper CT 32nd Annual International Carnahan Conference on Security Technology CY OCT 12-14, 1998 CL ALEXANDRIA, VA SP IEEE, Lexington Sect, IEEE, Aerosp & Electr Syst Soc, Chung Shan Inst Sci & Technol, Natl Chiao Tung Univ AB This paper describes the design and preliminary test results of a 360-degree scanning, multispectral intrusion detection sensor. This moderate-resolution, panoramic imaging sensor is intended for exterior use at ranges from 50 to 1500 meters. This Advanced Exterior Sensor (AES) uses three sensing technologies (infrared, visible, and radar), separate track processors and sensor fusion to provide low false-alarm intrusion detection, tracking, and immediate visual assessment. The images from the infrared and visible detector sets and the radar range data are updated as the sensors rotate about once per second. The radar provides range data with one-meter resolution. This sensor has been designed for low-cost, easy use and rapid deployment to cover wide areas beyond, or in place of, typical perimeters, and tactical applications around fixed or temporary high-value assets. A prototype AES has been developed and preliminary test results are presented. This sensor represents a growing trend to use low-cost thermal imaging sensors, combined with other devices and advanced processing, for protection of U.S. military forces and other national assets. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Pritchard, DA (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4536-3 PY 1998 BP 190 EP 195 DI 10.1109/CCST.1998.723788 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BL81S UT WOS:000076808100030 ER PT B AU Garcia, ML AF Garcia, ML BE Sanson, LD TI Development of security engineering curricula at US universities SO 32ND ANNUAL 1998 INTERNATIONAL CARNAHAN CONFERENCE ON SECURITY TECHNOLOGY LA English DT Proceedings Paper CT 32nd Annual International Carnahan Conference on Security Technology CY OCT 12-14, 1998 CL ALEXANDRIA, VA SP IEEE, Lexington Sect, IEEE, Aerosp & Electr Syst Soc, Chung Shan Inst Sci & Technol, Natl Chiao Tung Univ AB The Southwest Surety Institute was formed in June, 1996 by Arizona State University (ASU), New Mexico Institute of Mining and Technology (NM Tech), New Mexico State University (NMSU), and Sandia National Laboratories (SNL) to provide new educational programs in Security Engineering. This is the first science-based program of its kind in the United Slates, directed at educating Security Engineers to help government and industry address their security needs. Current courses include security system design, evaluation, principles, and technology, the criminal justice system, and explosives surety. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Garcia, ML (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4536-3 PY 1998 BP 230 EP 233 DI 10.1109/CCST.1998.723796 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL81S UT WOS:000076808100038 ER PT B AU Critchlow, T Ganesh, M Musick, R AF Critchlow, T Ganesh, M Musick, R BE Halper, M TI Meta-data based mediator generation SO 3RD IFCIS INTERNATIONAL CONFERENCE ON COOPERATIVE INFORMATION SYSTEMS - PROCEEDINGS LA English DT Proceedings Paper CT 3rd IFCIS International Conference on Cooperative Information Systems CY AUG 20-22, 1998 CL NEW YORK, NY SP Int Fdn Cooperat Informat Syst, New Jersey Inst Technol AB Mediators are a critical component of any data warehouse; they transform data from source formats to the warehouse representation while resolving semantic and syntactic conflicts. The close relationship between mediators and databases requires a mediator to be updated whenever an associated schema is modified. Failure to quickly perform these updates significantly reduces the reliability of the warehouse because queries do not have access to the most current data. This may result in incorrect or misleading responses, and reduce user confidence in the warehouse. Unfortunately, this maintenance may be a significant undertaking if a warehouse integrates several dynamic data sources. This paper describes a meta-data framework, and associated software, designed to automate a significant portion of the mediator generation task and thereby reduce the effort involved in adapting to schema changes. By allowing the DBA to concentrate on identifying the modifications at a high level, instead of reprogramming the mediator, turnaround time is reduced and warehouse reliability is improved. C1 Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. RP Critchlow, T (reprint author), Univ Calif Lawrence Livermore Natl Lab, Ctr Appl Sci Comp, Livermore, CA 94550 USA. NR 0 TC 3 Z9 3 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA BN 0-8186-8380-5 PY 1998 BP 168 EP 176 DI 10.1109/COOPIS.1998.706195 PG 9 WC Computer Science, Information Systems; Computer Science, Theory & Methods SC Computer Science GA BL61H UT WOS:000076010500017 ER PT B AU Klett, J AF Klett, J BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI High thermal conductivity, mesophase pitch-derived carbon foam SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn DE carbon foam; high thermal conductivity; and mesophase pitch AB A relatively simple technique for fabricating mesophase pitch-based carbon foam has been developed at Oak Ridge National Laboratory. This technique produces graphitic foam with an open cell structure and an extremely high bulk thermal conductivity, >100 W/m . K. The cell walls have a highly aligned graphitic structure, similar to high-performance carbon fibers, exhibiting interlayer spacing (d(002)) of 0.336 nm, coherence length (L-a,L-100) of 203 nm, and a stacking height (L-c,L-002) of 442 nm. Consequently, the foam cell walls (struts) exhibit a thermal conductivity between 700 and 1,200 W/m . K. Because of the low density (rho) of 0.5 g/cm(3), the specific thermal conductivity of the foam is more than four times greater than that of copper. C1 Oak Ridge Natl Lab, Carbon & Insulat Mat Technol Grp, Div Met & Ceram, Oak Ridge, TN 37831 USA. RP Klett, J (reprint author), Oak Ridge Natl Lab, Carbon & Insulat Mat Technol Grp, Div Met & Ceram, Oak Ridge, TN 37831 USA. RI Klett, James/E-6860-2017 OI Klett, James/0000-0002-2553-9649 NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 745 EP 755 PG 11 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500069 ER PT B AU Guthrie, SE Thomas, GJ AF Guthrie, SE Thomas, GJ BE Kliger, HS Rasmussen, BM Pilato, LA Tolle, TB TI A novel process for fabricating Mg2Ni SO 43RD INTERNATIONAL SAMPE SYMPOSIUM AND EXHIBITION ON MATERIALS AND PROCESS AFFORDABILITY - KEYS TO THE FUTURE, VOL 43 LA English DT Proceedings Paper CT 43rd International SAMPE Symposium and Exhibition on Materials and Process Affordability - Keys to the Future CY MAY 31-JUN 04, 1998 CL ANAHEIM, CA SP Soc Adv Mat & Proc Engn DE Mg2Ni; lightweight hydride; hydrogen storage AB The alloy, Mg2Ni, has a number of desirable properties for use as a lightweight reversible hydride for hydrogen storage applications. It has relatively good storage capacity (3.6 wt.% H-2 as Mg2NiH4) and a higher plateau pressure and lower operating temperature than MgH2. A novel low temperature (<300 degrees C) process is reported that does not require melting of the alloy constituents to achieve a single phase alloy of Mg2Ni. The process results in smaller particle dimensions without sacrifice in product yield and eliminates the need for post processing to achieve homogenization and particle sizing. It can also be implemented in-situ in storage vessels to greatly simplify fabrication while providing more material predictability during the activation process. The process is described and the hydride properties of the product are reported and compared to conventionally formed alloys. C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Guthrie, SE (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU SOC ADVANCEMENT MATERIAL & PROCESS ENGINEERING PI COVINA PA 1161 PARKVIEW DR,, COVINA, CA 91724-3748 USA BN 0-938994-79-4 PY 1998 BP 1105 EP 1112 PG 8 WC Materials Science, Multidisciplinary; Materials Science, Characterization & Testing; Materials Science, Composites; Polymer Science SC Materials Science; Polymer Science GA BL49K UT WOS:000075698500103 ER PT B AU Prono, J DeLanoy, M Deupree, R Skiby, J Thompson, B AF Prono, J DeLanoy, M Deupree, R Skiby, J Thompson, B GP SOC TECH COMMUN SOC TECH COMMUN TI Developing new levels of edit SO 45TH ANNUAL CONFERENCE ON IMAGINATION, INNOVATION AND COMMUNICATION LA English DT Proceedings Paper CT 47th Annual Conference on Imagination, Innovation and Communication CY MAY 17-20, 1998 CL ANAHEIM, CA AB In 1985, the writing and editing group at Los Alamos National Laboratory established four levels of edit for technical reports. When a survey in 1994 showed that both authors and editors felt the levels were not meeting author needs, we set about revising them. Our goals were to simplify the editing process, focus editing on improving technical clarity: and ensure that value Iras added in editing. This paper describes our revision process and product-three author-based levels of edit. C1 Univ Calif Los Alamos Natl Lab, Commun Arts & Serv Grp, Los Alamos, NM 87545 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU SOC TECHNICAL COMMUNICATION PI ARLINGTON PA 901 N STUART ST, SUITE 904, ARLINGTON, VA 22203-1854 USA BN 1-891709-00-3 PY 1998 BP 436 EP 440 PG 5 WC Communication SC Communication GA BQ71A UT WOS:000089239500171 ER PT B AU Dimos, D Yang, P AF Dimos, D Yang, P GP EIA EIA TI Direct-write fabrication of integrated, multilayer ceramic components SO 48TH ELECTRONIC COMPONENTS & TECHNOLOGY CONFERENCE - 1998 PROCEEDINGS SE PROCEEDINGS - ELECTRONIC COMPONENTS AND TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT 48th Electronic Components & Technology Conference CY MAY 25-28, 1998 CL SEATTLE, WA SP IEEE, Components Packaging Mfg Technol Soc, Electr Ind Assoc AB The need for advanced (electronic) ceramic components with smaller size, greater functionality, and enhanced reliability requires the ability to integrate electronic ceramics in complex 3-D architectures. However, traditional tape casting and screen printing approaches are poorly suited to the requirements of rapid prototyping and small-lot manufacturing. To address this need, we are developing a direct-write approach for fabricating highly integrated, multilayer components using a micropen to deposit slurries in precise patterns. This approach provides the ability to fabricate multifunctional, multimaterial integrated ceramic components (MMICCs) in an agile and rapid way, and has been used to make integrated passive devices such RC filters, inductors, and voltage transformers. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Dimos, D (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4526-6 J9 P ELECTR C PY 1998 BP 225 EP 227 DI 10.1109/ECTC.1998.678697 PG 3 WC Engineering, Electrical & Electronic SC Engineering GA BL14K UT WOS:000074438800034 ER PT B AU Malba, V Young, D Ou, JJ Bernhardt, AF Boser, BE AF Malba, V Young, D Ou, JJ Bernhardt, AF Boser, BE GP EIA EIA TI High-performance RF coil inductors on silicon SO 48TH ELECTRONIC COMPONENTS & TECHNOLOGY CONFERENCE - 1998 PROCEEDINGS SE PROCEEDINGS - ELECTRONIC COMPONENTS AND TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT 48th Electronic Components & Technology Conference CY MAY 25-28, 1998 CL SEATTLE, WA SP IEEE, Components Packaging Mfg Technol Soc, Electr Ind Assoc AB Strong demand for wireless communication devices has motivated research directed toward monolithic integration of transceivers. The fundamental electronic component least compatible with silicon integrated circuits is the inductor, although a number of inductors are required to implement oscillators, filters and matching networks in cellular devices. Spiral inductors have been integrated into the silicon IC metallization sequence but have not performed adequately due to coupling to the silicon which results in parasitic capacitance and loss. We have, for the first time, fabricated three dimensional coil inductors on silicon which have significantly lower capacitive coupling and loss and which now exceed the requirements of potential applications. Quality factors of 30 at 1 GHz have been measured in single turn devices and Q > 16 in 2 and 4 turn devices. The reduced Q for multiturn devices appears to be related to eddy currents in outer turns generated by magnetic fields from current in neighboring turns. Higher Q values significantly in excess of 30 are anticipated using modified coil designs. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Malba, V (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. NR 0 TC 7 Z9 8 U1 0 U2 2 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4526-6 J9 P ELECTR C PY 1998 BP 252 EP 255 DI 10.1109/ECTC.1998.678702 PG 4 WC Engineering, Electrical & Electronic SC Engineering GA BL14K UT WOS:000074438800039 ER PT B AU Palmer, DW Benson, DA Peterson, DW Sweet, JN AF Palmer, DW Benson, DA Peterson, DW Sweet, JN GP EIA EIA TI IC chip stress during plastic package molding SO 48TH ELECTRONIC COMPONENTS & TECHNOLOGY CONFERENCE - 1998 PROCEEDINGS SE PROCEEDINGS - ELECTRONIC COMPONENTS AND TECHNOLOGY CONFERENCE LA English DT Proceedings Paper CT 48th Electronic Components & Technology Conference CY MAY 25-28, 1998 CL SEATTLE, WA SP IEEE, Components Packaging Mfg Technol Soc, Electr Ind Assoc AB Approximately 95% of the world's integrated chips are packaged using a hot, high pressure transfer molding process. The stress created by the flow of silica powder loaded epoxy can displace the fine bonding wires and can even distort the metalization patterns under the protective chip passivation layer [1, 2]. In this study we developed a technique to measure the mechanical stress over the surface of an integrated circuit during the molding process. A CMOS test chip with 25 diffused resistor stress sensors was applied to a commercial lead frame. Both compression and shear stresses were measured at all 25 locations on the surface of the chip every 50 milliseconds during molding. These measurements have a fine time and stress resolution which should allow comparison with computer simulation of the molding process, thus allowing optimization of both the manufacturing process and mold geometry. C1 Sandia Natl Labs, Albuquerque, NM 87185 USA. RP Palmer, DW (reprint author), Sandia Natl Labs, POB 5800, Albuquerque, NM 87185 USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU IEEE PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 USA BN 0-7803-4526-6 J9 P ELECTR C PY 1998 BP 1326 EP 1331 DI 10.1109/ECTC.1998.678916 PG 6 WC Engineering, Electrical & Electronic SC Engineering GA BL14K UT WOS:000074438800209 ER PT S AU Johnson, T AF Johnson, T BE Kieffer, J TI Technology priorities: Results of the glass technology roadmap workshop SO 58TH CONFERENCE ON GLASS PROBLEMS SE CERAMIC ENGINEERING AND SCIENCE PROCEEDINGS LA English DT Proceedings Paper CT 58th Conference on Glass Problems CY OCT 14-15, 1997 CL UNIV ILLINOIS URBANA-CHAMPAIGN, URBANA, IL SP Ohio State Univ, Dept Mat Sci, Ohio State Univ, Dept Engn, Univ Illinois Urbana Champaign HO UNIV ILLINOIS URBANA-CHAMPAIGN AB The American glass industry has taken on important step in defining its future in response to changing market and business conditions. The industry faces exciting new opportunities but also serious challenges. New technology is expected to play a defining role in creating a competitive advantage for U.S. glass manufacturers. Advanced glass technology can lower production costs and create high-profit, innovative Products to compete with other materials and foreign competitors. However, the complexity of new products and the intensity of global competition require that glass producers adopt new strategies for developing and applying innovative technologies. C1 US Dept Energy, Washington, DC 20585 USA. RP Johnson, T (reprint author), US Dept Energy, Washington, DC 20585 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, WESTERVILLE, OH 43081-8720 USA SN 0196-6219 J9 CERAM ENG SCI PROC PY 1998 VL 19 IS 1 BP 99 EP 110 PG 12 WC Materials Science, Ceramics SC Materials Science GA BL07L UT WOS:000074177500008 ER PT B AU Nieto, MM AF Nieto, MM BE Kasperkovitz, P Grau, D TI Towards even and odd squeezed number states SO 5TH WIGNER SYMPOSIUM, PROCEEDINGS LA English DT Proceedings Paper CT 5th Wigner Symposium CY AUG 25-29, 1997 CL VIENNA, AUSTRIA AB The time evolution of even and odd squeezed states, as well as that of squeezed number states, has been given in simple, analytic form. This follows experimental work on trapped ions which has demonstrated even and odd coherent states, number states, and squeezed (but not displaced) ground states. We review this situation and consider the extension to even and odd squeezed number states. Questions of uncertainty relations are also discussed. C1 Univ Calif Los Alamos Natl Lab, Div Theoret T8 MSB285, Los Alamos, NM 87544 USA. RP Nieto, MM (reprint author), Univ Calif Los Alamos Natl Lab, Div Theoret T8 MSB285, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU WORLD SCIENTIFIC PUBL CO PTE LTD PI SINGAPORE PA PO BOX 128 FARRER RD, SINGAPORE 9128, SINGAPORE BN 981-02-3464-3 PY 1998 BP 453 EP 455 PG 3 WC Mathematics, Applied; Physics, Multidisciplinary; Physics, Mathematical SC Mathematics; Physics GA BL70A UT WOS:000076377700134 ER PT S AU Rao, NSV Batsell, SG AF Rao, NSV Batsell, SG BE Makki, K Chlamtac, I Pissinou, N TI On routing algorithms with end-to-end delay guarantees SO 7TH INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS AND NETWORKS - PROCEEDINGS SE IEEE INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS AND NETWORKS LA English DT Proceedings Paper CT 7th International Conference on Computer Communications and Networks CY OCT 12-15, 1998 CL LAFAYETTE, LA SP NASA, BellSouth, IEEE, Commun Soc, USA, Army Res Lab AB We consider the transmission. of a message of size r from a source to a destination. over a computer network with n nodes and m links. There are three sources of delays: (a) propagation delays along the links, (b) delays due to bandwidth availability on the links, and (c) queuing delays at the intermediate nodes. First, we consider that the delays on various links and nodes are given. as functions of the message site. If the delay in (b) is a non-increasing function Of the bandwidth, we propose O(m(2) + mnlogn) time algorithm to compute a path with the minimum end-to-end delay for any given message size r. We then consider that the queuing delay in (c) is a random variable correlated with the message size according to an unknown distribution. At each node. the measurements of queuing delays and message sizes are available. We propose too algorithms to compute paths whose delays are close to optimal delays with a high probability, irrespective of the distribution of the delays. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Rao, NSV (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU IEEE COMPUTER SOC PI LOS ALAMITOS PA 10662 LOS VAQUEROS CIRCLE, PO BOX 3014, LOS ALAMITOS, CA 90720-1264 USA SN 1095-2055 BN 0-8186-9014-3 J9 IEEE IC COMP COM NET PY 1998 BP 162 EP 167 DI 10.1109/ICCCN.1998.739912 PG 4 WC Computer Science, Information Systems; Telecommunications SC Computer Science; Telecommunications GA BL97V UT WOS:000077336300022 ER PT B AU Taljat, B Zacharia, T Wang, XL Keiser, JR Swindeman, RW Hubbard, CR AF Taljat, B Zacharia, T Wang, XL Keiser, JR Swindeman, RW Hubbard, CR GP CANADIAN PULP & PAPER ASSOC TI Mechanical design of steel tubing for use in black liquor recovery boilers SO 9TH INTERNATIONAL SYMPOSIUM ON CORROSION IN THE PULP AND PAPER INDUSTRY LA English DT Proceedings Paper CT 9th International Symposium on Corrosion in the Pulp and Paper Industry CY MAY 26-29, 1998 CL OTTAWA, CANADA SP Canadian Pulp & Paper Assoc, Tech Sect, TAPPI, NACE Int, Svenska Pappers och Cellulosaingeniorsforeningen, Suomen Paperi Insinoorien Yhdistys, Swedish Corros Inst AB Finite element models were developed for thermal-mechanical analysis of black liquor recovery boiler floor tubes. Residual stresses in boiler floors due to various manufacturing processes were analyzed. The modeling results were verified by X-ray and neutron diffraction measurements at room temperature on as-manufactured tubes as well as tubes after service. The established finite element models were then used to evaluate stress conditions during boiler operation. Using these finite element models, a parametric response surface study was performed to investigate the influence of material properties of the clad layer on stresses in the floor tubes during various boiler operating conditions, which yielded a generalized solution of stresses in the composite tube floors. The results of the study are useful for identifying the mechanisms of cracking experienced by recovery boilers. Based on the results of the response surface study, a recommendation was made for more suitable materials in terms of the analyzed mechanical properties. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Taljat, B (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Wang, Xun-Li/C-9636-2010; OI Wang, Xun-Li/0000-0003-4060-8777; Zacharia, Thomas/0000-0001-6463-5425 NR 0 TC 0 Z9 0 U1 0 U2 0 PU CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION PI MONTREAL PA SUN LIFE BLDG, 23RD FLOOR, 1155 METCALFE ST, MONTREAL, PQ H3B 2X9, CANADA BN 1-896742-28-9 PY 1998 BP 193 EP 197 PG 5 WC Engineering, Chemical; Materials Science, Paper & Wood SC Engineering; Materials Science GA BL19F UT WOS:000074636500028 ER PT B AU Swindeman, RW Keiser, JR Maziasz, PJ Singbeil, DL AF Swindeman, RW Keiser, JR Maziasz, PJ Singbeil, DL GP CANADIAN PULP & PAPER ASSOC TI Fatigue cracking of coextruded 304L/CS tubes SO 9TH INTERNATIONAL SYMPOSIUM ON CORROSION IN THE PULP AND PAPER INDUSTRY LA English DT Proceedings Paper CT 9th International Symposium on Corrosion in the Pulp and Paper Industry CY MAY 26-29, 1998 CL OTTAWA, CANADA SP Canadian Pulp & Paper Assoc, Tech Sect, TAPPI, NACE Int, Svenska Pappers och Cellulosaingeniorsforeningen, Suomen Paperi Insinoorien Yhdistys, Swedish Corros Inst AB The mechanical and thermal fatigue of austenitic stainless steels was examined for the maximum temperature range expected in coextruded floor tubes of recovery boilers;;to determine the likelihood that the cracking in the 304L stainless steel cladding could be fatigue related. The microstructures and cracking patterns of fatigue-tested specimens were compared to features observed in cracked cladding and significant differences were found which suggested that fatigue was not the most likely cause for failure. Biaxial thermal fatigue testing of coextruded tubes and panels was performed to gather more evidence of cracking patterns. Here, transient thermal stresses were imposed by rapidly heating the tubing surface with lamps. In spite of high surface temperatures, no cracks were produced in the 304L stainless steel cladding, and this observation was interpreted as evidence that cracking must be corrosion related. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Swindeman, RW (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. OI Maziasz, Philip/0000-0001-8207-334X NR 0 TC 0 Z9 0 U1 0 U2 0 PU CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION PI MONTREAL PA SUN LIFE BLDG, 23RD FLOOR, 1155 METCALFE ST, MONTREAL, PQ H3B 2X9, CANADA BN 1-896742-28-9 PY 1998 BP 209 EP 212 PG 4 WC Engineering, Chemical; Materials Science, Paper & Wood SC Engineering; Materials Science GA BL19F UT WOS:000074636500030 ER PT B AU Keiser, JR Taljat, B Wang, XL Swindeman, RW Maziasz, PJ Meyers, LE Thomas, RL Elliott, ST Singbeil, DL Prescott, R Gorog, JP AF Keiser, JR Taljat, B Wang, XL Swindeman, RW Maziasz, PJ Meyers, LE Thomas, RL Elliott, ST Singbeil, DL Prescott, R Gorog, JP GP CANADIAN PULP & PAPER ASSOC TI Causes and solutions for cracking of coextruded and weld overlay floor tubes in black liquor recovery boilers SO 9TH INTERNATIONAL SYMPOSIUM ON CORROSION IN THE PULP AND PAPER INDUSTRY LA English DT Proceedings Paper CT 9th International Symposium on Corrosion in the Pulp and Paper Industry CY MAY 26-29, 1998 CL OTTAWA, CANADA SP Canadian Pulp & Paper Assoc, Tech Sect, TAPPI, NACE Int, Svenska Pappers och Cellulosaingeniorsforeningen, Suomen Paperi Insinoorien Yhdistys, Swedish Corros Inst AB Cracking of coextruded, black liquor recovery boiler floor tubes is both a safety and an economic issue to mill operators. In an effort to determine the cause of the cracking and to identify a solution, extensive studies, described in this and three accompanying papers, are being conducted. In this paper, results of studies to characterize both the cracking and the chemical and thermal environment are reported. Based on the results described in this series of papers, a possible mechanism is presented and means to lessen the likelihood of cracking or to totally avoid cracking of floor tubes are offered. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Keiser, JR (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RI Wang, Xun-Li/C-9636-2010; OI Wang, Xun-Li/0000-0003-4060-8777; Maziasz, Philip/0000-0001-8207-334X NR 0 TC 0 Z9 0 U1 0 U2 1 PU CANADIAN PULP & PAPER ASSOC TECHNICAL SECTION PI MONTREAL PA SUN LIFE BLDG, 23RD FLOOR, 1155 METCALFE ST, MONTREAL, PQ H3B 2X9, CANADA BN 1-896742-28-9 PY 1998 BP 213 EP 220 PG 8 WC Engineering, Chemical; Materials Science, Paper & Wood SC Engineering; Materials Science GA BL19F UT WOS:000074636500031 ER PT S AU Kleinmann, RLP Hedin, RS Nairn, RW AF Kleinmann, RLP Hedin, RS Nairn, RW BE Geller, W Klapper, H Salomons, W TI Treatment of mine drainage by anoxic limestone drains and constructed wetlands SO ACIDIC MINING LAKES: ACID MINE DRAINAGE, LIMNOLOGY AND RECLAMATION SE ENVIRONMENTAL SCIENCE LA English DT Proceedings Paper CT International Symposium on the Abatement of Geogenic Acidification in Mining Lakes CY SEP, 1995 CL UFZ, DEPT INLAND WATERS RES, MAGDEBURG, GERMANY HO UFZ, DEPT INLAND WATERS RES C1 US DOE, Pittsburgh, PA 15236 USA. RP Kleinmann, RLP (reprint author), US DOE, POB 10940, Pittsburgh, PA 15236 USA. NR 24 TC 12 Z9 13 U1 1 U2 14 PU SPRINGER-VERLAG BERLIN PI BERLIN PA HEIDELBERGER PLATZ 3, D-14197 BERLIN, GERMANY SN 1431-6250 BN 3-540-63486-X J9 ENVIRONM SCI PY 1998 BP 303 EP 319 PG 17 WC Engineering, Environmental; Limnology; Water Resources SC Engineering; Marine & Freshwater Biology; Water Resources GA BM48E UT WOS:000078867600016 ER PT J AU Heilbronn, L Frankel, K Holabird, K Zeitlin, C McMahan, MA Rathbun, W Cronqvist, M Gong, W Madey, R Htun, M Elaasar, M Anderson, BD Baldwin, AR Jiang, J Keane, D Scott, A Shao, Y Watson, JW Zhang, WM Galonsky, A Ronningen, R Zecher, P Kruse, J Wang, J Westfall, GD Yenello, S Deak, F Horvath, A Kiss, A Seres, Z Schelin, H Stronach, C Cary, R AF Heilbronn, L Frankel, K Holabird, K Zeitlin, C McMahan, MA Rathbun, W Cronqvist, M Gong, W Madey, R Htun, M Elaasar, M Anderson, BD Baldwin, AR Jiang, J Keane, D Scott, A Shao, Y Watson, JW Zhang, WM Galonsky, A Ronningen, R Zecher, P Kruse, J Wang, J Westfall, GD Yenello, S Deak, F Horvath, A Kiss, A Seres, Z Schelin, H Stronach, C Cary, R TI Production of neutrons from interactions of GCR-like particles SO ACTA ASTRONAUTICA LA English DT Article ID PRODUCTION CROSS-SECTIONS; STOPPING-LENGTH TARGETS; 256-MEV PROTONS; MEV-NUCLEON; CARBON; YIELDS AB In order to help assess the risk to astronauts due to the long-term exposure to the natural radiation environment in space, an understanding bf how the primary radiation field is changed when passing through shielding and tissue materials must be obtained. One important aspect of the change in the primary radiation field after passing through shielding materials is the production of secondary particles from the breakup of the primary. Neutrons are an important component of the secondary particle field due to their relatively high biological weighting factors, and due to their relative abundance, especially behind thick shielding scenarios. Because of the complexity of the problem, the estimation of the risk from exposure to the secondary neutron field must be handled using calculational techniques. However, those calculations will need an extensive set of neutron cross section and thick-target neutron yield data in order to make an accurate assessment of the risk. In this paper we briefly survey the existing neutron-production data sets that are applicable to the space radiation transport problem, and we point out how neutron production from protons is different than neutron production from heavy ions. We also make comparisons of one the heavy-ion data sets with Boltzmann-Uehling-Uhlenbeck (BUU) calculations. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Heilbronn, L (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Horvath, Akos/D-1056-2012; Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 14 TC 0 Z9 0 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN-APR PY 1998 VL 42 IS 1-8 SI SI BP 363 EP 373 DI 10.1016/S0094-5765(98)00131-3 PG 11 WC Engineering, Aerospace SC Engineering GA 113KH UT WOS:000075549800032 PM 11541619 ER PT J AU Miller, J Zeitlin, C Heilbronn, L Borak, T Carter, T Frankel, KA Fukumura, A Murakami, T Rademacher, SE Schimmerling, W Stronach, C AF Miller, J Zeitlin, C Heilbronn, L Borak, T Carter, T Frankel, KA Fukumura, A Murakami, T Rademacher, SE Schimmerling, W Stronach, C TI Ground-based simulations of cosmic ray heavy ion interactions in spacecraft and planetary habitat shielding materials SO ACTA ASTRONAUTICA LA English DT Article ID FRAGMENTATION AB This paper surveys some recent accelerator-based measurements of the nuclear fragmentation of high energy nuclei in shielding and tissue-equivalent materials. These data are needed to make accurate predictions of the radiation field produced at depth in spacecraft and planetary habitat shielding materials and in the human body by heavy charged particles in the galactic cosmic radiation. Projectile-target combinations include 1 GeV/nucleon Fe-56 incident on aluminum and graphite and 600 MeV/nucleon Fe-56 and 290 MeV/nucleon C-12 On polyethylene. We present examples of the dependence of fragmentation on material type and thickness, of a comparison between data and a fragmentation model, and of multiple fragments produced dong the beam axis. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Miller, J (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RI Heilbronn, Lawrence/J-6998-2013 OI Heilbronn, Lawrence/0000-0002-8226-1057 NR 3 TC 7 Z9 7 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0094-5765 J9 ACTA ASTRONAUT JI Acta Astronaut. PD JAN-APR PY 1998 VL 42 IS 1-8 SI SI BP 389 EP 394 DI 10.1016/S0094-5765(98)00133-7 PG 6 WC Engineering, Aerospace SC Engineering GA 113KH UT WOS:000075549800034 PM 11541622 ER PT J AU Guo, XX Zhao, H Shi, DJ Xu, J Xu, XD Ru, BG AF Guo, XX Zhao, H Shi, DJ Xu, J Xu, XD Ru, BG TI Expression of mouse MT-I cDNA in filamentous cyanobacterium to enhance its metal-resistance SO ACTA BOTANICA SINICA LA Chinese DT Article DE mMT-I; smt O-P; transgenic filamentous cyanobacterium; heavy metal-resistance; Anabaena sp. PCC 7120 ID PROKARYOTIC METALLOTHIONEIN; LOCUS AB The cMT-like promoter (smt O-P) was used for the expression of mMT-I cDNA in cyanobacterium, Anabaena sp. PCC 7120, to enhance its metal-binding ability and specificity. Shuttle vector pKT-MRE was constructed and replicated in E. coli HB101, and triparental conjugate transfer was applied for transforming cyanobacterial cells. Sm-screening, Southern and Western blotting analysis were used for the identification of the transgenic cyanobacterium clones. Transgenic cyanobacterial metal-absorption ability, heavy metal-resistance and photosynthesis measurements in the medium containing heavy metal ion indicated that the expression of foreign mMT-I enhanced the cyanobacterial heavy metal-resistance to 1.5 times in the transgenic Anabaena sp. PCC 7120. C1 Peking Univ, Coll Life Sci, Natl Lab Prot & Plant Engn, Beijing 100871, Peoples R China. Chinese Acad Sci, Inst Bot, Beijing 100093, Peoples R China. Michigan State Univ, US DOE, Plant Res Lab, E Lansing, MI 48824 USA. RP Guo, XX (reprint author), Peking Univ, Coll Life Sci, Natl Lab Prot & Plant Engn, Beijing 100871, Peoples R China. NR 12 TC 4 Z9 4 U1 0 U2 0 PU SCIENCE PRESS PI BEIJING PA 16 DONGHUANGCHENGGEN NORTH ST, BEIJING 100717, PEOPLES R CHINA SN 0577-7496 J9 ACTA BOT SIN JI Acta Bot. Sin. PY 1998 VL 40 IS 4 BP 320 EP 324 PG 5 WC Biochemistry & Molecular Biology; Plant Sciences SC Biochemistry & Molecular Biology; Plant Sciences GA ZR139 UT WOS:000073941300006 ER PT J AU Dautant, A Meyer, JB Yariv, J Precigoux, G Sweet, RM Kalb, AJ Frolow, F AF Dautant, A Meyer, JB Yariv, J Precigoux, G Sweet, RM Kalb, AJ Frolow, F TI Structure of a monoclinic crystal form of cytochrome b1 (bacterioferritin) from E-coli SO ACTA CRYSTALLOGRAPHICA SECTION D-BIOLOGICAL CRYSTALLOGRAPHY LA English DT Article ID ESCHERICHIA-COLI; HEME-BINDING; FERRITIN; IRON; PROTEIN; GENE; PURIFICATION; SUBUNIT; OVERPRODUCTION; SEQUENCE AB Crystals of E. coli cytochrome bl, alias bacterioferritin, were grown from a low ionic strength solution. The resulting monoclinic P2(1) structure was solved by molecular replacement and refined using noncrystallographic symmetries applied to the fundamental unit, consisting of two protein subunits and a single haem. From the Patterson self-rotation results it was shown that the asymmetric unit of the monoclinic crystal consists of 12 such dimers and corresponds to a complete, nearly spherical, molecule of bacterioferritin (M-r = 450 kDa) of 432 point-group symmetry. It is thus the most symmetrical cytochrome. As previously determined for the tetragonal form, the haem is located in a special position on a local twofold axis of the dimer. A bimetal centre is also observed within the four-helix bundle of each monomer; a metal-binding site is located on the fourfold axis. C1 Univ Bordeaux 1, ERS133 CNRS, Unite Biophys Struct, F-33405 Talence, France. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. Fac Chem, Weizmann Inst Sci, Rehovot, Israel. RP Dautant, A (reprint author), Univ Bordeaux 1, ERS133 CNRS, Unite Biophys Struct, F-33405 Talence, France. RI Frolow, Felix/A-1760-2013 NR 42 TC 40 Z9 42 U1 0 U2 8 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 JAN 1 PY 1998 VL 54 BP 16 EP 24 DI 10.1107/S0907444997006811 PN 1 PG 9 WC Biochemical Research Methods; Biochemistry & Molecular Biology; Biophysics; Crystallography SC Biochemistry & Molecular Biology; Biophysics; Crystallography GA YW685 UT WOS:000071962300002 PM 9867433 ER PT J AU Brannon, RM AF Brannon, RM TI Caveats concerning conjugate stress and strain measures for frame indifferent anisotropic elasticity SO ACTA MECHANICA LA English DT Article ID CONSTITUTIVE LAWS AB Small-distortion constitutive laws are often extemporaneously generalized to large deformations by merely applying them in the unrotated material frame or, equivalently, by using polar rates. This approach does render the resulting constitutive model indifferent to large superimposed rigid rotations, but it may lead to incorrect predictions for both the magnitude and direction of stress whenever there is significant material distortion. To demonstrate this claim, an exact large-deformation solution is derived for the stress in an idealized fiber-reinforced composite. This example shows that the Cauchy tangent stiffness tensor (corresponding to the conjugate pair of Cauchy stress and the symmetric part of the velocity gradient) must evolve in both magnitude and direction whenever the material distorts. Volume changes necessarily lead to a loss of major-symmetry of this Cauchy tangent stiffness tensor, which can be rectified by instead using specific or Kirchhoff stress. A previous work that correctly pointed out the need for the Cauchy stiffness tensor to distort is shown to have overlook:ed an additional contribution from the rate of distortion. Some of the anomalous properties of the Cauchy stiffness tensor are eradicated by instead using the second Piola-Kirchhoff stress or, equivalently, convected coordinates. Such an approach, however, demands accurate measurements of large-distortion material response, not only to obtain physically realistic results, but also to avoid potential instabilities in numerical computations. C1 Sandia Natl Labs, Dept Computat Phys & Mech, Albuquerque, NM 87185 USA. RP Brannon, RM (reprint author), Sandia Natl Labs, Dept Computat Phys & Mech, POB 5800, Albuquerque, NM 87185 USA. NR 6 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG WIEN PI VIENNA PA SACHSENPLATZ 4-6, PO BOX 89, A-1201 VIENNA, AUSTRIA SN 0001-5970 J9 ACTA MECH JI Acta Mech. PY 1998 VL 129 IS 1-2 BP 107 EP 116 DI 10.1007/BF01379653 PG 10 WC Mechanics SC Mechanics GA ZL005 UT WOS:000073389300008 ER PT J AU Seinost, G Gasser, R Reisinger, E Rigler, MY Fischer, L Keplinger, A Dattwyler, RJ Dunn, JJ Klein, W AF Seinost, G Gasser, R Reisinger, E Rigler, MY Fischer, L Keplinger, A Dattwyler, RJ Dunn, JJ Klein, W TI Cardiovascular manifestations of Lyme disease and effects upon left ventricular dysfunction SO ACTA MEDICA AUSTRIACA LA German DT Article DE dilated cardiomyopathy; Lyme disease; antibiotics; ceftriaxone; Borrelia burgdorferi ID IDIOPATHIC DILATED CARDIOMYOPATHY; BORRELIA-BURGDORFERI; DIAGNOSIS; CEFTRIAXONE; CARDITIS; ECHOCARDIOGRAPHY; RECOMMENDATIONS; MYOCARDITIS; SPIROCHETE; INFECTION AB Borrelia burgdorferi infection (BBI) is suggested to be associated with dilated cardiomyopathy (IDC). Stanek et al. were able to cultivate Borrelia burgdorferi (BB) from myocardial biopsy tissue of a patient with longstanding dilated cardiomyopathy. Here we present a study in which we examined the effect of standard antibiotic treatment on the left ventricular ejection fraction (LV-EF) in patients with dilated cardiomyopathy associated with BBI. In this study we assessed the serum (IgG, IgM ELISA; Western Blot) and the history of 46 IDC-patients with specific respect to BBI (mean LV-EF: 30.4 +/- 1.3%; measured by cardiac catheterisation and echocardiography - length-area-volume method). All 46 patients received standard treatment for dilated cardiomyopathy: ACE-inhibitors, digitalis and diuretics. 11 (24%) patients showed positive serology and a history of BBI; 9 of these also had a typical history of tick bite and erythema chronicum migrans (ECM) and/or other organ involvement, 2 had no recollection of tick bite or EMC, but showed other BE-associated disorders (neuropathy, oligoarthritis). These II patients with BBI received standard antibiotic treatment with intraveneous ceftriaxone 2 g bid for 14 days. 6 (55%) recovered completely and showed a normal LV-EF after 6 months, 3 (27%) improved their LV-EF and 2 (18%) did not improve at all. This amounts to 9 (82%) recovery/improvement in the BE-group. The 35 patients who did not show positive serology or a history of BBI did not receive antibiotic treatment. In this group without BBI 12 (26%) showed recovery/improvement following the standard treatment of dilated cardiomyopathy (see above). Our results indicate that BBI could play a decisive role in the development of dilated cardiomyopathy, especially in a geographical region as Graz, where BE is endemic. While aware of the small number of BE-patients in this study, we nevertheless conclude that, in a remarkable number of patients with signs of BBI, dilated cardiomyopathy could be reversed and LV-EF improved upon standard antibiotic treatment. C1 SUNY Stony Brook, Dept Med, Div Clin Immunol Allergy, Stony Brook, NY 11794 USA. Graz Univ, Med Klin, Klin Abt Kardiol, A-8036 Graz, Austria. Brookhaven Natl Lab, Dept Biol, Upton, NY 11973 USA. RP Seinost, G (reprint author), SUNY Stony Brook, Dept Med, Div Clin Immunol Allergy, Stony Brook, NY 11794 USA. EM gseinost@mail.som.sunysb.edu NR 53 TC 4 Z9 4 U1 0 U2 0 PU BLACKWELL WISSENSCHAFTS-VERLAG GMBH PI BERLIN PA KURFURSTENDAMM 57, D-10707 BERLIN, GERMANY SN 0303-8173 J9 ACTA MED AUST JI Acta Med. Austriaca PY 1998 VL 25 IS 2 BP 44 EP 50 PG 7 WC Medicine, General & Internal SC General & Internal Medicine GA ZX762 UT WOS:000074552600002 PM 9681041 ER PT J AU Blakely, EA AF Blakely, EA TI Radiation-induced changes in a cell's program for life SO ACTA ONCOLOGICA LA English DT Editorial Material C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, Berkeley, CA 94720 USA. RP Blakely, EA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Life Sci, 1 Cyclotron Rd,Mailstop 70A-1118, Berkeley, CA 94720 USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU SCANDINAVIAN UNIVERSITY PRESS PI OSLO PA PO BOX 2959 TOYEN, JOURNAL DIVISION CUSTOMER SERVICE, N-0608 OSLO, NORWAY SN 0284-186X J9 ACTA ONCOL JI Acta Oncol. PY 1998 VL 37 IS 2 BP 127 EP 128 PG 2 WC Oncology SC Oncology GA ZR604 UT WOS:000073995200003 PM 9636006 ER PT J AU Geiger, K Longacre, R AF Geiger, K Longacre, R TI Interplay of parton and hadron cascades in nucleus - Nucleus collisions at CERN SPS and RHIC SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article ID SPACE-TIME DESCRIPTION; ULTRARELATIVISTIC ENERGIES; MONTE-CARLO; QCD; MODEL; DYNAMICS; VENUS AB We introduce a Monte-Carlo space-time model for high-energy collisions with nuclei, involving the dynamical interplay of perturbative QCD parton production and evolution, with non-perturbative parton-cluster formation and 'afterburner' cascading of formed pre-hadronic clusters plus hadron excitations. This approach allows us to trace the space-time history of parton and hadron degrees of freedom of nuclear collisions on the microscopical level of parton and hadron cascades in both position and momentum space, from the instant of nuclear overlap to the final yield of particles. In applying this approach, we analyze Pb + Pb collisions at the CERN SPS with beam energy 158 GeV (root s/A = 17 GeV) and Au + Au collisions at RHIC with collider energy root s/A = 200 GeV. We find that the perturbative QCD parton production and cascade development provides an important contribution to particle production at central rapidities, and that the 'afterburner' cascading of pre-hadronic clusters and formed hadrons emerging from the parton cascade is essential. The overall agreement of our model calculations including the 'afterburner' cascading with the observed particle spectra at the CERN SPS is fairly good, whereas the neglect of the final-state interactions among hadronic excitations deviates significantly. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Geiger, K (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 38 TC 10 Z9 10 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 8 IS 1-2 BP 41 EP 67 PG 27 WC Physics, Nuclear SC Physics GA 112EE UT WOS:000075480500004 ER PT J AU Dobado, A Pelaez, JR AF Dobado, A Pelaez, JR TI On the size of the chiral condensate, generalized chiral perturbation theory and the DIRAC experiment SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article ID PI-PI-SCATTERING; FINITE-TEMPERATURE; LOW-ENERGY; SYMMETRY BREAKING; QUARK CONDENSATE; 2 LOOPS; QCD; CORRELATORS; AMPLITUDE; MESONS AB In the near future, the DIRAC collaboration will measure pi pi scattering lengths with great precision. Those measurements are likely to shed some light on the problem of the size of the chiral [0\(q) over bar q\0] condensate. Although it is usually assumed to be as large as similar to (-225 MeV)(3), in the last years a more general approach has been developed to accommodate either a large or a small alternative similar to (-100 MeV)(3). Such a low value would also modify the standard temperature estimate at which the chiral phase transition occurs. In this work we briefly review the basic theoretical ideas related to this issue as well as the experiment that could help to establish any of the two scenarios. C1 Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain. Stanford Univ, Stanford Linear Accelerator Ctr, Stanford, CA 94309 USA. RP Univ Complutense Madrid, Dept Fis Teor, E-28040 Madrid, Spain. EM dobado@eucmax.sim.ucm.es; pelaez@slac.stanford.edu RI Pelaez, Jose/K-9767-2014 OI Pelaez, Jose/0000-0003-0737-4681 NR 49 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO RT PI BUDAPEST PA PRIELLE K U 19, PO BOX 245,, H-1117 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 8 IS 4 BP 307 EP 321 PG 15 WC Physics, Nuclear SC Physics GA 162JB UT WOS:000078341500004 ER PT J AU Joss, DT Paul, ES Semple, AT Nolan, PJ Clark, RM Lee, IY Fallon, P Asztalos, SJ Cederwall, B Deleplanque, MA Diamond, RM Macchiavelli, AO Stephens, FS Hauschild, K Hibbert, IM O'Brien, NJ Wadsworth, R Becker, JA Bernstein, L Farris, LP Kelly, WH AF Joss, DT Paul, ES Semple, AT Nolan, PJ Clark, RM Lee, IY Fallon, P Asztalos, SJ Cederwall, B Deleplanque, MA Diamond, RM Macchiavelli, AO Stephens, FS Hauschild, K Hibbert, IM O'Brien, NJ Wadsworth, R Becker, JA Bernstein, L Farris, LP Kelly, WH TI Lifetime measurements of a triaxial band in Ce-133 SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT International Symposium on Exotic Nuclear Shapes CY MAY 12-17, 1997 CL DEBRECEN, HUNGARY ID SHELL AB The Doppler shift attenuation method has been used to determine the transition quadrupole moment of a triaxial band belonging to the gamma-soft nucleus, Ce-133. Doppler broadened lineshape (DBLS) analysis has revealed the magnitude of the Q(t) value to be similar to 2.4 eb. This contribution provides new information of (i) the transition quadrupole moment of this band (ii) the lifetimes of in-band and sidefeeding transitions and (iii) the relative deformations of coexisting nuclear shapes. C1 Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. Univ York, York Y01 5DD, N Yorkshire, England. Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. Iowa State Univ, Ames, IA 50011 USA. RP Joss, DT (reprint author), Univ Liverpool, Oliver Lodge Lab, Liverpool L69 7ZE, Merseyside, England. RI Cederwall, Bo/M-3337-2014; Hauschild, Karl/A-6726-2009 OI Cederwall, Bo/0000-0003-1771-2656; NR 6 TC 0 Z9 0 U1 1 U2 1 PU AKADEMIAI KIADO RT PI BUDAPEST PA PRIELLE K U 19, PO BOX 245,, H-1117 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 1 BP 111 EP 112 PG 2 WC Physics, Nuclear SC Physics GA 112DB UT WOS:000075477900018 ER PT J AU Bender, M Rutz, K Burvenich, T Reinhard, PG Maruhn, JA Greiner, W AF Bender, M Rutz, K Burvenich, T Reinhard, PG Maruhn, JA Greiner, W TI Superheavy nuclei in self-consistent models SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article ID MEAN-FIELD THEORY; GROUND-STATE PROPERTIES; EFFECTIVE FORCES; HEAVIEST ELEMENTS; FISSION-BARRIERS; SHELL STRUCTURE; DRIP-LINE; PARAMETRIZATION; STABILITY; SPACE AB The shell structure of superheavy nuclei is investigated within various parametrizations of relativistic and nonrelativistic nuclear mean-field models. The heaviest known even-even nuclei are used as a benchmark to estimate the predictive value of the models. From that starting point, spherical and deformed shell closures in the superheavy region are searched. C1 Univ Frankfurt, Inst Theoret Phys, D-60325 Frankfurt, Germany. Gesell Schwerionenforsch GmbH, D-64291 Darmstadt, Germany. Univ Erlangen Nurnberg, Inst Theoret Phys 2, D-91058 Erlangen, Germany. Oak Ridge Natl Lab, Joint Inst Heavy Ion Res, Oak Ridge, TN 37831 USA. RP Bender, M (reprint author), Univ Frankfurt, Inst Theoret Phys, Robert Mayer Str 10, D-60325 Frankfurt, Germany. NR 38 TC 1 Z9 1 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 2 BP 167 EP 184 PG 18 WC Physics, Nuclear SC Physics GA 112DC UT WOS:000075478000003 ER PT J AU Solem, JC AF Solem, JC TI Status of research in gamma-ray lasers SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Review ID NUCLEAR-EXCITATION; SYNCHROTRON RADIATION; ELECTRON TRANSITION; QUANTUM COHERENCE; INVERSION; SUPERFLUORESCENCE; SCATTERING; EMISSION; AMPLIFICATION; KINETICS AB This article reviews conceptual devices designed to generate coherent high-quantum-energy radiation by stimulating nuclear transitions in solids; and delineates some of the promising areas of research. Solid state gamma-ray lasers can benefit from (1) Mossbauer effect or recoilless emission, which suppresses first-order Doppler broadening, and brings the emitting nuclei close to a common resonant frequency; and (2) Borrmann effect, which suppresses non-resonant scattering and absorption, and may allow a crystal lattice to act as a distributed resonator. I discuss some of the basic physics that governs the performance of conceptual gamma-ray lasers, and some of the classic approaches to design. Many of these early schemes were shown to be unworkable decades ago, but re-emerge in different forms generally without attention to the fallacies already revealed. Other schemes have languished for lack of a champion. I also describe some exciting new approaches, particularly those utilizing techniques for suppressing resonant absorption, which can realize gain without a true inversion. Finally, I submit some recommendations for future research. C1 Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. RP Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA. NR 105 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO RT PI BUDAPEST PA PRIELLE K U 19, PO BOX 245,, H-1117 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 2 BP 185 EP 205 PG 21 WC Physics, Nuclear SC Physics GA 112DC UT WOS:000075478000004 ER PT J AU Geiger, K Muller, B AF Geiger, K Muller, B TI How dense does parton matter get in Pb+Pb collisions at the CERN SPS? SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article ID HEAVY-ION COLLISIONS; RELATIVISTIC NUCLEAR COLLISIONS; PSI' SUPPRESSION; J/PSI; QCD; CASCADES AB We examine the qualitative features of parton production through materialization in heavy-ion collisions within perturbative QCD, and estimate the magnitude of the resulting parton density created during the early stage of the collisions. The implications for "anomalous" J/psi suppression observed in Pb + Pb collisions at the CERN SPS are discussed. We argue that the A-dependence of absorption of J/psi by (partonic) comovers is steeper than assumed in most phenomenological models, because the absorption process is dominated by quasi-perturbative QCD interactions. Our argument is supported by results recently obtained in the framework of the parton cascade model. We predict significant "anomalous" suppression for Pb + Pb collisions at the CERN-SPS, but not for S + U collisions. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. Duke Univ, Dept Phys, Durham, NC 27708 USA. RP Geiger, K (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 24 TC 8 Z9 8 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 2 BP 207 EP 213 PG 7 WC Physics, Nuclear SC Physics GA 112DC UT WOS:000075478000005 ER PT J AU Mezei, F AF Mezei, F TI Neutronenwirtschaft SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article AB Advanced accelerator technology allows us today to produce large quantities of neutrons from electricity economically as efficiently as by fission reactors, but with a hugely enhanced flexibility of delivery, which resembles to that of other industrial commodities. With the new capability of transmuting tons of a vast variety of elements into another each year, the commodity neutron becomes a potential key factor in the management of the environment and the resources of the Earth. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. Hahn Meitner Inst Kernforsch Berlin GmbH, D-1000 Berlin, Germany. RP Mezei, F (reprint author), Univ Calif Los Alamos Natl Lab, POB 1663, Los Alamos, NM 87544 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 2 BP 215 EP 218 PG 4 WC Physics, Nuclear SC Physics GA 112DC UT WOS:000075478000006 ER PT J AU Browne, JC Venneri, F Li, N Williamson, MA AF Browne, JC Venneri, F Li, N Williamson, MA TI Accelerator-driven Transmutation of Waste SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article AB Taking advantage of the recent breakthroughs in accelerator technology and of the natural flexibility of subcritical systems, the Accelerator-driven Transmutation of Waste (ATW) concept offers the United States and other countries the possibility to essentially eliminate plutonium, higher actinides, and environmentally hazardous fission products from the waste stream destined for permanent storage. C1 Univ Calif Los Alamos Natl Lab, Los Alamos ATW Project, Los Alamos, NM 87544 USA. RP Browne, JC (reprint author), Univ Calif Los Alamos Natl Lab, Los Alamos ATW Project, POB 1663, Los Alamos, NM 87544 USA. NR 3 TC 6 Z9 6 U1 3 U2 4 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 2 BP 249 EP 258 PG 10 WC Physics, Nuclear SC Physics GA 112DC UT WOS:000075478000010 ER PT J AU Lee, TSH Lopez, JA Morales, J Thondikulam, G AF Lee, TSH Lopez, JA Morales, J Thondikulam, G TI Separable potentials for the hadronic phase SO ACTA PHYSICA HUNGARICA NEW SERIES-HEAVY ION PHYSICS LA English DT Article; Proceedings Paper CT 2nd Latin American Workshop on Nuclear and Heavy Ion Physics CY SEP 01-05, 1997 CL UNIV SIMON BOLIVAR, CARACAS, VENEZUELA HO UNIV SIMON BOLIVAR AB To understand the hadronic phase to be formed in RHIC experiments, the interaction potentials that reproduce nucleon-nucleon scattering data at modern energies are determined. We obtain analytical expressions for the T-matrix, phase shifts and NN potentials using computer-based symbolic mathematics. C1 Argonne Natl Lab, Argonne, IL 60439 USA. Univ Texas, El Paso, TX 79968 USA. RP Lee, TSH (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 4 TC 0 Z9 0 U1 0 U2 0 PU AKADEMIAI KIADO PI BUDAPEST PA PO BOX 245, H-1519 BUDAPEST, HUNGARY SN 1219-7580 J9 ACTA PHYS HUNG NS-H JI Acta Phys. Hung. New Ser.-Heavy Ion Phys. PY 1998 VL 7 IS 3-4 BP 263 EP 274 PG 12 WC Physics, Nuclear SC Physics GA 112DE UT WOS:000075478200002 ER PT J AU Myers, WD Swiatecki, WJ AF Myers, WD Swiatecki, WJ TI A macroscopic model of nuclear rotation SO ACTA PHYSICA POLONICA B LA English DT Article; Proceedings Paper CT XXV Mazurian Lakes School of Physics CY AUG 27-SEP 06, 1997 CL PIASKI, POLAND SP Andrzej Soltan Inst Nucl Phys, Warsaw Univ, Tempus, Polish State Comm Sci Res, Natl Atom Agcy ID MASSES AB We have formulated a statistical model of nuclear properties that combines the Thomas-Fermi assumption of two fermions per h(3) of phase space with an effective interaction between the nucleons. The model has been employed in the calculation of nuclear masses and density distributions. The initial calculations assumed spherical symmetry but a later extension to three dimensions permits the calculation of fission saddle-point shapes and the corresponding fission barriers. It is also possible to include angular momentum and we have constructed an extension of the model which describes approximately ground-state, superdeformed and fission-isomeric rotational bands of even-even nuclei. The model is based on a three-term energy expression corresponding to: a) a rigid rotation of part of the nucleus, b) the energy of initially counter-rotating gyroscopes that the overall rotation gradually aligns in the direction of the total angular momentum, and c) a potential energy resisting such alignment. The model can be used for a macroscopic description of the angular momentum dependence of nuclear fission barriers. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, Berkeley, CA 94720 USA. RP Myers, WD (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Div Nucl Sci, 1 Cyclotron Rd, Berkeley, CA 94720 USA. NR 11 TC 2 Z9 2 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 JAN-FEB PY 1998 VL 29 IS 1-2 BP 313 EP 323 PG 11 WC Physics, Multidisciplinary SC Physics GA ZD260 UT WOS:000072667400025 ER PT S AU Boggs, SE Lin, RP Feffer, PT Slassi-Sennou, S McBride, S Primbsch, JH Youssefi, K Zimmer, G Cork, C Luke, P Madden, N Malone, D Pehl, R Pelling, M Cotin, F Vedrenne, G AF Boggs, SE Lin, RP Feffer, PT Slassi-Sennou, S McBride, S Primbsch, JH Youssefi, K Zimmer, G Cork, C Luke, P Madden, N Malone, D Pehl, R Pelling, M Cotin, F Vedrenne, G BE Riedler, W Torkar, K TI A high resolution gamma-ray and hard x-ray spectrometer (HIREGS) for long duration balloon flights SO ACTIVE EXPERIMENTS IN SPACE PLASMAS SE ADVANCES IN SPACE RESEARCH LA English DT Article; Proceedings Paper CT 31st COSPAR Scientific Assembly CY JUL 14-21, 1996 CL BIRMINGHAM, ENGLAND SP Comm Space Res, World Climate Res Programme, European Space Agcy, NOAA, Natl Environm Satellite Data & Informat Sci, Sci Comm Ocean Res, Int Union Geol Sci, Int Astronaut Federat, Int Decade Nat Disaster Reduct, UNESCO, UN, Off Outer Space Affairs AB The HIREGS gamma-ray spectrometer made a 23-day Long Duration Balloon Flight (LDBF) from Antarctica in January 1995 to observe Galactic sources of gamma-ray and hard X-ray line and continuum emission, The scientific instrument itself is discussed, followed by a more extensive discussion of the characteristics of the instrument unique to LDBFs. The flight performance and preliminary results are briefly summarized. (C) 1998 COSPAR. Published by Elsevier Science Ltd. C1 Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. Univ Calif Berkeley, Dept Phys, Berkeley, CA 94720 USA. Univ Calif San Diego, Ctr Astrophys & Space Sci, La Jolla, CA 92093 USA. Ctr Etud Spatiale Rayonnements, F-31029 Toulouse, France. Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA. RP Boggs, SE (reprint author), Univ Calif Berkeley, Space Sci Lab, Berkeley, CA 94720 USA. RI Boggs, Steven/E-4170-2015 OI Boggs, Steven/0000-0001-9567-4224 NR 5 TC 5 Z9 5 U1 0 U2 0 PU PERGAMON PRESS LTD PI OXFORD PA THE BOULEVARD LANGFORD LANE KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0273-1177 BN 0-08-043460-6 J9 ADV SPACE RES PY 1998 VL 21 IS 7 BP 1015 EP 1018 DI 10.1016/S0273-1177(97)01090-9 PG 4 WC Engineering, Aerospace; Astronomy & Astrophysics; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Engineering; Astronomy & Astrophysics; Geology; Meteorology & Atmospheric Sciences GA BL02N UT WOS:000074073000014 ER PT B AU Fenimore, EE AF Fenimore, EE BE Scarsi, L Bradt, H Giommi, P Fiore, F TI Gamma-ray burst spectra and time histories from 2 to 400 keV SO ACTIVE X-RAY SKY: RESULTS FROM BEPPOSAX AND RXTE LA English DT Proceedings Paper CT Active X-Ray Sky Conference CY OCT 21-24, 1997 CL ROME, ITALY AB The Gamma-Ray burst detector on Ginga consisted of a proportional counter to observe the x-rays and a scintillation counter to observe the gamma-rays. It was ideally suited to study the x-rays associated with gamma-ray bursts (GRBs). Ginga detected similar to 120 GRBs and 22 of them had sufficient statistics to determine spectra from 2 to 400 keV. Although the Ginga and BATSE trigger criteria were very similar, the distribution of spectral parameters was different. Ginga observed bend energies in the spectra down to 2 keV and had a larger fraction of bursts with low energy power law indexes greater than zero. The average ratio of energy in the x-ray band (2 to 10 keV) compared to the gamma-ray band (50 to 300 keV) was 24%. Some events had more energy in the x-ray band than in the gamma-ray band. One Ginga event had a period of time preceding the gamma rays that was effectively pure x-ray emission. This x-ray "preactivity" might be due to the penchant for the GRB time structure to be broader at lower energy rather than a different physical process. The x-rays tend to rise and fall slower than the gamma rays but they both tend to peak at about the same time. This argues against models involving the injection of relativistic electrons that cool by synchrotron radiation. C1 Univ Calif Los Alamos Natl Lab, Los Alamos, NM 87544 USA. RP Fenimore, EE (reprint author), Univ Calif Los Alamos Natl Lab, MS D436, Los Alamos, NM 87544 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS BN 0-444-82990-3 PY 1998 BP 635 EP 639 PG 5 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA BL61F UT WOS:000076009100123 ER PT S AU Gavel, DT Friedman, HW AF Gavel, DT Friedman, HW BE Bonaccini, D Tyson, RK TI Measurements of the Lick Observatory sodium laser guide star SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ AB The Lick Observatory guide star laser has provided a beacon sufficient to close the adaptive optics loop and produce corrected images during runs in 1996 and 1997. This report summarizes measurements of the wavefront quality of the outgoing beam, photoreturn signal from the sodium beacon, and radiance distribution of the guide star on the sky, and follows with an analysis of the impact of the laser on adaptive optics system performance. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Gavel, DT (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808,L-458, Livermore, CA 94550 USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 254 EP 259 DI 10.1117/12.321680 PG 6 WC Optics SC Optics GA BL80V UT WOS:000076793400028 ER PT S AU Friedman, HW Cooke, JB Danforth, PM Erbert, GV Feldman, M Gavel, DT Jenkins, SL Jones, HE Kanz, VK Kuklo, T Newman, MJ Pierce, EL Presta, RW Salmon, JT Thompson, GR Wong, NJ AF Friedman, HW Cooke, JB Danforth, PM Erbert, GV Feldman, M Gavel, DT Jenkins, SL Jones, HE Kanz, VK Kuklo, T Newman, MJ Pierce, EL Presta, RW Salmon, JT Thompson, GR Wong, NJ BE Bonaccini, D Tyson, RK TI Design and performance of a laser guide star system for the Keck II telescope SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE sodium laser; guide star; adaptive optics AB A laser system to generate sodium-layer guide stars has been designed, built and delivered to the Keck Observatory in Hawaii. The system uses frequency doubled YAG lasers to pump liquid dye lasers and produces 20 W of average power. The design and performance results of this laser system are presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA. RP Friedman, HW (reprint author), Univ Calif Lawrence Livermore Natl Lab, Box 808,L-464, Livermore, CA 94551 USA. NR 0 TC 7 Z9 7 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 260 EP 276 DI 10.1117/12.321681 PG 17 WC Optics SC Optics GA BL80V UT WOS:000076793400029 ER PT S AU Max, CE Macintosh, B Olivier, SS Gavel, DT Friedman, HW AF Max, CE Macintosh, B Olivier, SS Gavel, DT Friedman, HW BE Bonaccini, D Tyson, RK TI Observing techniques for astronomical laser guide star adaptive optics SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE adaptive optics; laser guide stars; point spread function AB We discuss astronomical observing requirements and their implementation using sodium-layer laser guide star adaptive optics. Specific issues requiring implementation include the ability to place the astronomical object at different locations within the field of view; reliable subtraction of Rayleigh-scattered Light; efficient focusing; and stable point-spread-function characterization. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Max, CE (reprint author), Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. OI Max, Claire/0000-0003-0682-5436 NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 277 EP 281 DI 10.1117/12.321706 PG 5 WC Optics SC Optics GA BL80V UT WOS:000076793400030 ER PT S AU Brase, JM An, J Avicola, K Beeman, BV Gavel, DT Hurd, R Johnston, B Jones, H Kuklo, T Max, CE Olivier, SS Waltjen, KE Watson, J AF Brase, JM An, J Avicola, K Beeman, BV Gavel, DT Hurd, R Johnston, B Jones, H Kuklo, T Max, CE Olivier, SS Waltjen, KE Watson, J BE Bonaccini, D Tyson, RK TI The wavefront control system for the Keck Telescope SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE adaptive optics; laser guide star; deformable mirror; Keck Telescope AB The laser guide star adaptive optics system currently being developed for the Keck 2 telescope consists of several major subsystems: the optical bench, wavefront control, user interface and supervisory control, and the laser system. The paper describes the design and implementation of the wavefront control subsystem that controls a 349 actuator deformable mirror for high order correction and tip-tilt mirrors for stabilizing the image and laser positions. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Brase, JM (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. OI Max, Claire/0000-0003-0682-5436 NR 0 TC 4 Z9 4 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 517 EP 521 DI 10.1117/12.321687 PG 5 WC Optics SC Optics GA BL80V UT WOS:000076793400057 ER PT S AU Avicola, K Watson, J Beeman, B Kuklo, T Taylor, J AF Avicola, K Watson, J Beeman, B Kuklo, T Taylor, J BE Bonaccini, D Tyson, RK TI Design and performance of the tip-tilt subsystem for the Keck II telescope adaptive optics system SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ AB A tip-tilt control system has been built as part of the adaptive optics system for the Keck II telescope on Mauna Kea in Hawaii. This system is used to correct for wavefront tip-tilt when the adaptive optics system is in the laser guide star mode, and it uses a natural star as the reference. The system consists of a tip-tilt sensor, fast steering mirror, and digital controller. The tip-tilt sensor is based on a quadrant lens assembly with fiber-optics coupling to four photon counting silicon avalanche photodiodes (APDs). The fast steering mirror mount has three PZT actuators with position sensors, and an 8 inch Silicon Carbide lightweight mirror. The controller accommodates a range of integration times, and includes automatic light level control, and an adaptive control algorithm which optimizes control performance with changing tilt star image sizes. The design and performance characteristics of a tip-tilt control system for the Keck II telescope are presented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Avicola, K (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 0 TC 4 Z9 5 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 628 EP 637 DI 10.1117/12.321629 PG 10 WC Optics SC Optics GA BL80V UT WOS:000076793400069 ER PT S AU Carrano, CJ Olivier, SS Brase, JM Macintosh, BA An, JR AF Carrano, CJ Olivier, SS Brase, JM Macintosh, BA An, JR BE Bonaccini, D Tyson, RK TI Phase retrieval techniques for adaptive optics SO ADAPTIVE OPTICAL SYSTEM TECHNOLOGIES, PARTS 1 AND 2 SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT SPIE Conference on Adaptive Optical System Technologies CY MAR 23-26, 1998 CL KONA, HI SP SPIE, European So Observ DE adaptive optics; phase retrieval; phase diversity; optical system calibration AB We have developed and tested a method for minimizing static aberrations in adaptive optics systems. In order to correct the static phase aberrations, we need to measure the aberrations through the entire system. We have employed various phase retrieval algorithms to detect these aberrations. We have performed simulations of our experimental setup demonstrating that phase retrieval can improve the static aberrations to below the 20 nn rms level, with the limiting factor being local turbulence in the AO system. Experimentally thus far, we have improved the static aberrations down to the 50 nm level, with the limiting factor being the ability to adjust the deformable mirror. This should be improved with better control algorithms now being implemented. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Carrano, CJ (reprint author), Univ Calif Lawrence Livermore Natl Lab, POB 808, Livermore, CA 94550 USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2800-0 J9 P SOC PHOTO-OPT INS PY 1998 VL 3353 BP 658 EP 667 DI 10.1117/12.321633 PG 10 WC Optics SC Optics GA BL80V UT WOS:000076793400072 ER PT B AU Nieh, TG AF Nieh, TG BE Ciach, R TI High strain rate superplasticity in some lightweight alloys and their composites SO ADVANCED LIGHT ALLOYS AND COMPOSITES SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SUB-SERIES 3, HIGH TECHNOLOGY LA English DT Proceedings Paper CT Conference of the NATO Advanced Study Institute on Advanced Light Alloys and Composites CY SEP 05-15, 1997 CL ZAKOPANE, POLAND SP NATO Sci Affairs Div, European Mat Res Soc, Polish State Comm Sci Res, Polish Minist Econ AB Over the last decade, superplasticity at high strain rates (>10(-1) s(-1)) has been reported in many fine grain structural materials, including metal-matrix composites, mechanically-alloyed materials, and modified conventional alloys. Up to date, there exists extensive data indicating superplastic strain rate increases with decreasing grain size. However, some recent experimental evidences also suggest that the presence of a small amount of liquid phase at interfaces or grain boundaries can influence the deformation mechanisms and enhance the strain rate for superplasticity. In the present paper, two alloy systems- 2124 Al and ZK60 Mg, and their metal matrix composites are examined. Micro structure-superplastic property relations for each alloy and its composite are characterized and compared to illustrate the optimal microstructural and testing conditions for achieving high-strain-rate superplasticity. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Nieh, TG (reprint author), Univ Calif Lawrence Livermore Natl Lab, L-369, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 0 U2 2 PU SPRINGER PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-5222-X J9 NATO ASI 3 HIGH TECH PY 1998 VL 59 BP 467 EP 476 PG 10 WC Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering; Materials Science, Composites SC Materials Science; Metallurgy & Metallurgical Engineering GA BM15V UT WOS:000077846100062 ER PT S AU Thomas, N Wolfe, J Farmer, J AF Thomas, N Wolfe, J Farmer, J BE Stepp, LM TI Protected silver coating for astronomical mirrors SO ADVANCED TECHNOLOGY OPTICAL/IR TELESCOPES VI SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Advanced Technology Optical/IR Telescopes VI CY MAR 23-25, 1998 CL KONA, HI SP SPIE, European SO Observ AB A durable protected silver coating was designed and fabricated for use on flashlamp reflectors in the National Ignition Facility (NIF) to avoid tarnishing under corrosive conditions and intense visible light. This coating provides a valuable alternative for telescope mirror coatings where high reflectance and durability are important requirements. This paper describes a protected silver coating having high reflectance from 400 nm to 10,000 nm. An alternate coating design extends the high reflectance down to 300 nm while maintaining high reflectance out to 10,000 nm The specular reflectance is between 95% and 97% in the visible region and 98% or better in the infrared region. C1 Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94550 USA. RP Thomas, N (reprint author), Univ Calif Lawrence Livermore Natl Lab, 7000 E Ave, Livermore, CA 94550 USA. NR 0 TC 13 Z9 14 U1 0 U2 1 PU SPIE-INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA 1000 20TH ST, PO BOX 10, BELLINGHAM, WA 98227-0010 USA SN 0277-786X BN 0-8194-2799-3 J9 P SOC PHOTO-OPT INS PY 1998 VL 3352 BP 580 EP 586 DI 10.1117/12.319243 PG 7 WC Astronomy & Astrophysics; Optics SC Astronomy & Astrophysics; Optics GA BL66H UT WOS:000076232300059 ER PT B AU Viswanathan, S Brinkman, CR Prugert, RM AF Viswanathan, S Brinkman, CR Prugert, RM BE Tiryakioglu, M Campbell, J TI The metal compression forming process SO ADVANCES IN ALUMINUM CASTING TECHNOLOGY LA English DT Proceedings Paper CT Materials Solutions Conference 98 on Aluminum Casting Technology CY OCT 12-15, 1998 CL ROSEMONT, IL SP ASM Int AB Metal Compression Forming (MCF) is a variant of the squeeze casting process, in which molten metal is allowed to solidify under pressure in order to close porosity and form a sound part. However, the MCF process applies pressure on the entire mold face, thereby directing pressure on all regions of the casting and producing a uniformly sound part. The process is capable of producing parts with properties close to those of forgings, while retaining the near net shape, complexity in geometry, and relatively low cost of the casting process. The paper describes the casting process development involved in the production of an aluminum A357 alloy motor mount bracket, including the use of a filling and solidification model to design the gating and determine process parameters. Tensile properties of the component are presented and correlated with those of forged components. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Viswanathan, S (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 0-87170-667-9 PY 1998 BP 39 EP 43 PG 5 WC Materials Science, Composites SC Materials Science GA BM49F UT WOS:000078896200004 ER PT B AU Viswanathan, S Sabau, AS Han, Q Duncan, AJ AF Viswanathan, S Sabau, AS Han, Q Duncan, AJ BE Tiryakioglu, M Campbell, J TI Modeling of porosity in aluminum alloy castings SO ADVANCES IN ALUMINUM CASTING TECHNOLOGY LA English DT Proceedings Paper CT Materials Solutions Conference 98 on Aluminum Casting Technology CY OCT 12-15, 1998 CL ROSEMONT, IL SP ASM Int AB As part of a program to develop codes for the prediction of microporosity in cast lightweight automotive structural parts, permeability measurements have been conducted on aluminum-4.5% copper alloy and the measured permeabilities have been related to the solidification microstructure. A comprehensive methodology taking into account mold filling, solidification, shrinkage-driven interdendritic fluid flow, hydrogen precipitation, and porosity evolution has been developed for the prediction of microporosity and macroporosity. Microporosity distributions have also been experimentally determined for plate and bar castings of aluminum-4.5% copper alloy over a wide range of solidification conditions. These experimentally determined porosity distributions are correlated to results from the computer model. Based on these results, the model will be used to predict porosity distributions in a complex shaped casting. C1 Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. RP Viswanathan, S (reprint author), Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA. NR 19 TC 1 Z9 1 U1 0 U2 0 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 0-87170-667-9 PY 1998 BP 135 EP 138 PG 4 WC Materials Science, Composites SC Materials Science GA BM49F UT WOS:000078896200017 ER PT B AU Horstemeyer, MF Mosher, DA AF Horstemeyer, MF Mosher, DA BE Tiryakioglu, M Campbell, J TI High strain rate effects on cast A356 aluminum alloy SO ADVANCES IN ALUMINUM CASTING TECHNOLOGY LA English DT Proceedings Paper CT Materials Solutions Conference 98 on Aluminum Casting Technology CY OCT 12-15, 1998 CL ROSEMONT, IL SP ASM Int C1 Sandia Natl Labs, Livermore, CA 94550 USA. RP Horstemeyer, MF (reprint author), Sandia Natl Labs, Livermore, CA 94550 USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ASM INTERNATIONAL PI MATERIALS PARK PA 9503 KINSMAN RD, MATERIALS PARK, OH 44073 USA BN 0-87170-667-9 PY 1998 BP 149 EP 150 PG 2 WC Materials Science, Composites SC Materials Science GA BM49F UT WOS:000078896200019 ER PT S AU Petersen, OW Ronnov-Jessen, L Weaver, VM Bissell, MJ AF Petersen, OW Ronnov-Jessen, L Weaver, VM Bissell, MJ BE VandeWoude, GF Klein, G TI Differentiation and cancer in the mammary gland: Shedding light on an old dichotomy SO ADVANCES IN CANCER RESEARCH, VOL 75 SE Advances in Cancer Research LA English DT Review ID BREAST-CARCINOMA-CELLS; RECONSTITUTED BASEMENT-MEMBRANE; TRANSFORMING GROWTH-FACTOR; RECEPTOR ER CDNA; EPITHELIAL-CELLS; EXTRACELLULAR-MATRIX; ESTROGEN-RECEPTOR; GENE-EXPRESSION; INTEGRIN EXPRESSION; BETA-1 INTEGRINS C1 Univ Copenhagen, Panum Inst, Inst Med Anat, Struct Cell Biol Unit, DK-2200 Copenhagen N, Denmark. Rigshosp, Finsen Lab, DK-2100 Copenhagen O, Denmark. Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Petersen, OW (reprint author), Univ Copenhagen, Panum Inst, Inst Med Anat, Struct Cell Biol Unit, DK-2200 Copenhagen N, Denmark. RI Ronnov-Jessen OR Ronnovjessen, Lone/A-5981-2013 FU NCI NIH HHS [CA64786-02, R01 CA064786, R01 CA064786-05, R37 CA064786] NR 144 TC 50 Z9 53 U1 1 U2 4 PU ELSEVIER ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-230X BN 0-12-006675-0 J9 ADV CANCER RES JI Adv.Cancer Res. PY 1998 VL 75 BP 135 EP 161 DI 10.1016/S0065-230X(08)60741-1 PG 29 WC Oncology SC Oncology GA BM54X UT WOS:000079074200004 PM 9709809 ER PT J AU Tomasik, P Schilling, CH AF Tomasik, P Schilling, CH TI Complexes of starch with inorganic guests SO ADVANCES IN CARBOHYDRATE CHEMISTRY AND BIOCHEMISTRY, VOL 53 SE ADVANCES IN CARBOHYDRATE CHEMISTRY AND BIOCHEMISTRY LA English DT Review ID CYCLODEXTRIN INCLUSION COMPLEXES; POTATO STARCH; CIRCULAR-DICHROISM; IODINE COMPLEXES; RESONANCE RAMAN; AMYLOSE; WATER; BLUE; CONFORMATION; TRIIODIDE C1 Hugon Kollataj Acad Agr, Dept Chem & Phys, PL-30059 Krakow, Poland. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. RP Tomasik, P (reprint author), Hugon Kollataj Acad Agr, Dept Chem & Phys, PL-30059 Krakow, Poland. NR 644 TC 63 Z9 65 U1 2 U2 15 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-2318 J9 ADV CARBOHYD CHEM BI JI Adv.Carbohydr.Chem.Biochem. PY 1998 VL 53 BP 263 EP 343 DI 10.1016/S0065-2318(08)60046-3 PG 81 WC Biochemistry & Molecular Biology; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA BM54V UT WOS:000079073400007 ER PT J AU Tomasik, P Schilling, CH AF Tomasik, P Schilling, CH TI Complexes of starch with organic guests SO ADVANCES IN CARBOHYDRATE CHEMISTRY AND BIOCHEMISTRY, VOL 53 SE ADVANCES IN CARBOHYDRATE CHEMISTRY AND BIOCHEMISTRY LA English DT Review ID NUCLEAR-MAGNETIC-RESONANCE; AMYLOSE-LIPID COMPLEXES; DIFFERENTIAL SCANNING CALORIMETRY; WHEAT-STARCH; INCLUSION COMPLEXES; POTATO STARCH; INCREASING TEMPERATURE; PHYSICAL-PROPERTIES; SUGAR SOLUTIONS; WATER MOBILITY C1 Hugon Kollataj Acad Agr, Dept Chem & Phys, PL-30059 Krakow, Poland. Iowa State Univ Sci & Technol, Ames Lab, Ames, IA 50011 USA. Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA. RP Tomasik, P (reprint author), Hugon Kollataj Acad Agr, Dept Chem & Phys, PL-30059 Krakow, Poland. NR 489 TC 65 Z9 67 U1 2 U2 9 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 USA SN 0065-2318 J9 ADV CARBOHYD CHEM BI JI Adv.Carbohydr.Chem.Biochem. PY 1998 VL 53 BP 345 EP 426 DI 10.1016/S0065-2318(08)60047-5 PG 82 WC Biochemistry & Molecular Biology; Chemistry, Organic SC Biochemistry & Molecular Biology; Chemistry GA BM54V UT WOS:000079073400008 ER PT S AU DuBois, DL AF DuBois, DL BE Inui, T Anpo, M Izui, K Yanagida, S Yamaguchi, T TI Development of electrocatalysts for carbon dioxide reduction using polydentate ligands to probe structure-activity relationships SO ADVANCES IN CHEMICAL CONVERSIONS FOR MITIGATING CARBON DIOXIDE SE STUDIES IN SURFACE SCIENCE AND CATALYSIS LA English DT Article; Proceedings Paper CT 4th International Conference on Carbon Dioxide Utilization CY SEP 07-11, 1997 CL KYOTO, JAPAN SP Chem Soc Japan, Res Assoc CO2 Chem Fixat, Res Inst Innovat Technol Earth, Commemorat Assoc Japan World Exposit 1970, New Energy & Ind Technol Dev Org, Federat Elect Power Co, Japan Automobile Manufacturers, Japan Chem Ind Assoc, Engn Adv Assoc Japan, Cement Assoc Japan ID ELECTROCHEMICAL CO2 REDUCTION; ELECTRON-TRANSFER; COMPLEXES; ADSORPTION; CATALYSTS; MONOXIDE; HYDROGEN; WATER AB This paper describes the use of polydentate ligands to optimize the performance of palladium catalysts for CO2 reduction and to probe mechanistic aspects of catalytic reactions. Polydentate ligands can be used to precisely control coordination environments, electronic properties, and specific steric interactions that can lead to new insights into the relationship between catalyst structure and activity. C1 Natl Renewable Energy Lab, Golden, CO 80401 USA. RP DuBois, DL (reprint author), Natl Renewable Energy Lab, 1617 Cole Blvd, Golden, CO 80401 USA. NR 28 TC 1 Z9 1 U1 1 U2 2 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82574-6 J9 STUD SURF SCI CATAL PY 1998 VL 114 BP 43 EP 53 PG 11 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical; Environmental Sciences SC Chemistry; Engineering; Environmental Sciences & Ecology GA BK88Q UT WOS:000073803900005 ER PT S AU Fujita, E Brunschwig, BS Cabelli, D Renner, MW Furenlid, LR Ogata, T Wada, Y Yanagida, S AF Fujita, E Brunschwig, BS Cabelli, D Renner, MW Furenlid, LR Ogata, T Wada, Y Yanagida, S BE Inui, T Anpo, M Izui, K Yanagida, S Yamaguchi, T TI Photochemical carbon dioxide reduction with metal complexes: Differences between cobalt and nickel macrocycles SO ADVANCES IN CHEMICAL CONVERSIONS FOR MITIGATING CARBON DIOXIDE SE STUDIES IN SURFACE SCIENCE AND CATALYSIS LA English DT Article; Proceedings Paper CT 4th International Conference on Carbon Dioxide Utilization CY SEP 07-11, 1997 CL KYOTO, JAPAN SP Chem Soc Japan, Res Assoc CO2 Chem Fixat, Res Inst Innovat Technol Earth, Commemorat Assoc Japan World Exposit 1970, New Energy & Ind Technol Dev Org, Federat Elect Power Co, Japan Automobile Manufacturers, Japan Chem Ind Assoc, Engn Adv Assoc Japan, Cement Assoc Japan ID ELECTROCATALYTIC REDUCTION; COORDINATION MODE; AQUEOUS-SOLUTION; ABINITIO MO; CO2; BINDING; THERMODYNAMICS; ACTIVATION; SPECTROSCOPY; KINETICS C1 Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. Brookhaven Natl Lab, Dept Appl Sci, Upton, NY 11973 USA. Brookhaven Natl Lab, Natl Synchrotron Light Source Dept, Upton, NY 11973 USA. Osaka Univ, Grad Sch Engn, Suita, Osaka 565, Japan. RP Fujita, E (reprint author), Brookhaven Natl Lab, Dept Chem, Upton, NY 11973 USA. RI Brunschwig, Bruce/G-4249-2011; Fujita, Etsuko/D-8814-2013 NR 28 TC 1 Z9 1 U1 1 U2 13 PU ELSEVIER SCIENCE PUBL B V PI AMSTERDAM PA SARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-2991 BN 0-444-82574-6 J9 STUD SURF SCI CATAL PY 1998 VL 114 BP 97 EP 106 PG 10 WC Chemistry, Applied; Chemistry, Physical; Engineering, Chemical; Environmental Sciences SC Chemistry; Engineering; Environmental Sciences & Ecology GA BK88Q UT WOS:000073803900010 ER PT J AU Zhong, GM Guiochon, G AF Zhong, GM Guiochon, G TI Fundamentals of simulated moving bed chromatography under linear conditions SO ADVANCES IN CHROMATOGRAPHY, VOL 39 SE ADVANCES IN CHROMATOGRAPHY LA English DT Review ID COUNTERCURRENT ADSORPTION SEPARATION; FRUCTOSE GLUCOSE SEPARATION; ROBUST DESIGN; LIQUID-CHROMATOGRAPHY; NUMERICAL-SIMULATION; CHIRAL EPOXIDE; SYSTEM; OPERATION; ADSORBER; MODEL C1 Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. Oak Ridge Natl Lab, Div Chem & Analyt Sci, Oak Ridge, TN 37831 USA. RP Zhong, GM (reprint author), Univ Tennessee, Dept Chem, Knoxville, TN 37996 USA. NR 80 TC 8 Z9 8 U1 2 U2 6 PU MARCEL DEKKER PI NEW YORK PA 270 MADISON AVE, NEW YORK, NY 10016 USA SN 0065-2415 J9 ADV CHROMATOGR PY 1998 VL 39 BP 351 EP 400 PG 50 WC Chemistry, Analytical SC Chemistry GA BK60A UT WOS:000072707700007 ER PT B AU Schenter, GK Garrett, BC Gai, H Dang, LX AF Schenter, GK Garrett, BC Gai, H Dang, LX BE Hase, WL TI Comparison of classical and quantum statistical mechanical simulations of aqueous ionic clusters SO ADVANCES IN CLASSICAL TRAJECTORY METHODS, VOL 3: COMPARISONS OF CLASSICAL AND QUANTUM DYNAMICS SE ADVANCES IN CLASSICAL TRAJECTORY METHODS : A RESEARCH ANNUAL LA English DT Proceedings Paper CT Mesilla Chemistry Workshop on Comparisons of Classical and Quantum Dynamics CY 1997 CL MESILLA, NM AB Comparison is made of classical and quantum mechanical treatments of nuclear motion on thermally averaged structural and energetic properties of aqueous clusters. At finite temperatures, radial distribution functions and enthalpies of formation are computed using classical and path integral Monte Carlo simulations. Diffusion Monte Carlo simulations are used to calculate quantum mechanical enthalpies of formation at 0 K. Calculations are reported for Cl-(H2O)(n) and I-(H2O)(n) with n = 1-6, for temperatures from 0 to 300 K. Comparisons are also made with properties computed within the harmonic approximation, which is often used to extend electronic structure calculations to finite temperatures, using the geometries, energies, and frequencies at minimum-energy geometries. It is found that the quantum mechanical results can differ markedly from the classical ones, particularly at the lower temperatures. We discuss the implications of these findings for obtaining analytical fits to potential energy surfaces and for interpreting experimental investigations into cluster structure. C1 Battelle Mem Inst, Pacific NW Labs, Environm Mol Sci Lab, Richland, WA 99352 USA. RP Schenter, GK (reprint author), Battelle Mem Inst, Pacific NW Labs, Environm Mol Sci Lab, POB 999, Richland, WA 99352 USA. RI Garrett, Bruce/F-8516-2011; Schenter, Gregory/I-7655-2014 OI Schenter, Gregory/0000-0001-5444-5484 NR 0 TC 9 Z9 9 U1 0 U2 2 PU JAI PRESS INC PI STAMFORD PA 100 PROSPECT STREET, STAMFORD, CT 06901-1640 USA BN 0-7623-0445-6 J9 ADV CLAS TR PY 1998 VL 3 BP 1 EP 33 PG 33 WC Chemistry, Physical; Physics, Atomic, Molecular & Chemical SC Chemistry; Physics GA BL94T UT WOS:000077261000001 ER PT S AU Kane, SF Siewert, TA McCowan, CN Farland, AL AF Kane, SF Siewert, TA McCowan, CN Farland, AL BE Balachandran, UB Gubser, DG Hartwig, KT Reed, RP Warnes, WH Bardos, VA TI Welding consumable development for a cryogenic (4 K) application SO ADVANCES IN CRYOGENIC ENGINEERING MATERIALS, VOL 44, PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT 12th International Cryogenic Materials Conference (ICMC) CY JUL 28-AUG 01, 1997 CL PORTLAND, OR SP Cabot Performance Mat, Oxford Instruments, Intermagnet Gen Corp ID TOUGHNESS; METALS AB This paper summarizes the development and qualification of an appropriate welding consumable for a demanding cryogenic magnet application. This research shows that higher oxygen content in the weld manifests itself as inclusions, which have a severe detrimental effect upon the fracture toughness at 4 K. Also, welds enriched with manganese and nickel have demonstrated improved fracture toughness. These discoveries were combined in the development of a nitrogen- and manganese-modified, high-nickel stainless-steel alloy. It produced gas metal are welds with superior cryogenic mechanical properties when welding procedures were modified to reduce the oxygen content. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kane, SF (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 22 TC 0 Z9 0 U1 0 U2 1 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45918-3 J9 ADV CRYOG ENG PY 1998 VL 44 BP 89 EP 96 PN A AND B PG 8 WC Thermodynamics; Materials Science, Multidisciplinary SC Thermodynamics; Materials Science GA BM41R UT WOS:000078666200012 ER PT S AU Kane, SF Farland, AL AF Kane, SF Farland, AL BE Balachandran, UB Gubser, DG Hartwig, KT Reed, RP Warnes, WH Bardos, VA TI Techniques for automatic autogenous welding of low sulfur 316LN beam tube SO ADVANCES IN CRYOGENIC ENGINEERING MATERIALS, VOL 44, PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT 12th International Cryogenic Materials Conference (ICMC) CY JUL 28-AUG 01, 1997 CL PORTLAND, OR SP Cabot Performance Mat, Oxford Instruments, Intermagnet Gen Corp ID TOUGHNESS AB Leaks and questionable penetration were found in some autogenous machine welded joints between the RHIC beam tube and flange located in the interconnect region. This investigation found the leaks were caused by hot cracking resulting from complications in welding low-sulfur, low-ferrite stainless steel. The marginal penetration is attributed to the joint design and the low sulfur content of the beam tube. Both problems are corrected using the same welding machine with specific electrode placement relative to the joint, and the addition of hydrogen to the shield gas. Repairs only should be accomplished with the addition of filler metal. C1 Brookhaven Natl Lab, Upton, NY 11973 USA. RP Kane, SF (reprint author), Brookhaven Natl Lab, Upton, NY 11973 USA. NR 10 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45918-3 J9 ADV CRYOG ENG PY 1998 VL 44 BP 105 EP 112 PN A AND B PG 8 WC Thermodynamics; Materials Science, Multidisciplinary SC Thermodynamics; Materials Science GA BM41R UT WOS:000078666200014 ER PT S AU Green, MA Mukherjee, SK Dardin, SM O'Neill, JW Marrs, RE Magee, E AF Green, MA Mukherjee, SK Dardin, SM O'Neill, JW Marrs, RE Magee, E BE Balachandran, UB Gubser, DG Hartwig, KT Reed, RP Warnes, WH Bardos, VA TI Tests of fill fibers and epoxy resins for the fabrication of impregnated superconducting solenoids SO ADVANCES IN CRYOGENIC ENGINEERING MATERIALS, VOL 44, PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT 12th International Cryogenic Materials Conference (ICMC) CY JUL 28-AUG 01, 1997 CL PORTLAND, OR SP Cabot Performance Mat, Oxford Instruments, Intermagnet Gen Corp AB While fabricating a 6 tesla superconducting solenoid for an EBIT experiment(1) at the Lawrence Livermore National Laboratory, a pair of test solenoids were wound and potted to test fill fibers and resins systems for impregnating tightly wound superconducting solenoids. Two types of fibers were used as layer to layer insulation and to fill spaces between 0.75 mm diameter formvar insulated wires. Two resin systems with different cure temperatures were tested. Ground plane insulation with and without sheets of mica was also tested. Two closely packed solenoids with an outside diameter of 150 mm were wound on an aluminum mandrel. Once the solenoids were wound and resin impregnated, they were quickly cooled to 77 K using liquid nitrogen. After the cold shock test, the coils were inspected and sectioned. The results of these tests are presented in this report. C1 Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. RP Green, MA (reprint author), Univ Calif Berkeley, Lawrence Berkeley Lab, Berkeley, CA 94720 USA. NR 6 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45918-3 J9 ADV CRYOG ENG PY 1998 VL 44 BP 205 EP 210 PN A AND B PG 6 WC Thermodynamics; Materials Science, Multidisciplinary SC Thermodynamics; Materials Science GA BM41R UT WOS:000078666200027 ER PT S AU Ostenson, JE Breitwisch, MJ Kouzoudis, D Finnemore, DK AF Ostenson, JE Breitwisch, MJ Kouzoudis, D Finnemore, DK BE Balachandran, UB Gubser, DG Hartwig, KT Reed, RP Warnes, WH Bardos, VA TI Growth of transient phases during Bi(2212) to Bi(2223) transformation SO ADVANCES IN CRYOGENIC ENGINEERING MATERIALS, VOL 44, PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT 12th International Cryogenic Materials Conference (ICMC) CY JUL 28-AUG 01, 1997 CL PORTLAND, OR SP Cabot Performance Mat, Oxford Instruments, Intermagnet Gen Corp ID PB-DOPED BI2SR2CA1CU2O8+DELTA; BI2SR2CA2CU3O10+DELTA AB Hot stage X-ray measurements and hot stage environmental electron scanning microscopy (ESEM) measurements have been used to study the intermediate phases that grow as the Bi(2212) grains begin to transforms into Bi(2223). The primary purpose is to investigate transient phases that may appear at the interface between the Bi(2212) grains and a Ag overlay while the temperature is being ramped to the reaction temperature at a rate comparable to that used in the commercial processing of tape conductors. Pb-doped Bi(2212) is metastable and is found to decompose and recrystallize during the ramp up to the reaction temperature. In addition, above about 973 K (700 degrees C), hillocks are found to grow between the flat surfaces of the Bi(2212) grains and the Ag overlay. Scanning Auger measurements show that these hillocks are composed of crystals of(Sr,Ca)O about 100 nm in diameter and have a Sr/Ca ratio of about 1.5. This growth of hillocks occurs on the time scale of tens of minutes and it may temporarily deplete the Bi(2212) grains of Sr leaving them Ca rich. C1 US DOE, Ames Lab, Ames, IA 50011 USA. RP Ostenson, JE (reprint author), US DOE, Ames Lab, Ames, IA 50011 USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45918-3 J9 ADV CRYOG ENG PY 1998 VL 44 BP 443 EP 447 PN A AND B PG 5 WC Thermodynamics; Materials Science, Multidisciplinary SC Thermodynamics; Materials Science GA BM41R UT WOS:000078666200058 ER PT S AU Xu, Y Goretta, KC Cuber, MM Burdt, ML Feng, LR Chen, N Balachandran, U Xu, M AF Xu, Y Goretta, KC Cuber, MM Burdt, ML Feng, LR Chen, N Balachandran, U Xu, M BE Balachandran, UB Gubser, DG Hartwig, KT Reed, RP Warnes, WH Bardos, VA TI Processing considerations for adding nanometer-scale oxides to enhance flux pinning in high-temperature superconductors SO ADVANCES IN CRYOGENIC ENGINEERING MATERIALS, VOL 44, PTS A AND B SE ADVANCES IN CRYOGENIC ENGINEERING LA English DT Proceedings Paper CT 12th International Cryogenic Materials Conference (ICMC) CY JUL 28-AUG 01, 1997 CL PORTLAND, OR SP Cabot Performance Mat, Oxford Instruments, Intermagnet Gen Corp ID CRITICAL-CURRENT-DENSITY; CU-O; SINGLE-CRYSTALS; SHEATHED TAPES; BI2SR2CACU2OX; ADDITIONS; CENTERS; PHASE; TI; TLBA2CA2CU3OX AB Several nanometer-scale oxide inclusions were added to Bi2Sr2CaCu2Ox high-temperature superconductors to determine their effectiveness in creating intragranular flux-pinning sites. Powder pellets were fabricated and heat treated by partial-melt processing. Effects of the additives on melting response, superconducting properties, and microstructural development were examined. Al2O3 additions exhibited the most promise for forming stable pinning centers, ZrO2 and SnO2 additions were moderately promising, TiO2, Fe2O3, and ZnO additions were less promising, and Y2O3 additions destroyed superconductivity. C1 Argonne Natl Lab, Argonne, IL 60439 USA. RP Xu, Y (reprint author), Argonne Natl Lab, 9700 S Cass Ave, Argonne, IL 60439 USA. NR 28 TC 0 Z9 0 U1 0 U2 0 PU PLENUM PRESS DIV PLENUM PUBLISHING CORP PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0065-2482 BN 0-306-45918-3 J9 ADV CRYOG ENG PY 1998 VL 44 BP 493 EP 500 PN A AND B PG 8 WC Thermodynamics; Materials Science, Multidisciplinary SC Thermodynamics; Materials Science GA BM41R UT WOS:000078666200065 ER EF